cas 21442-01-3, N-(2-HYDROXYPROPYL)METHACRYLAMIDE

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RETRACTED ARTICLE: Folic acid mediated endocytosis enhanced by modified multi stimuli nanocontainers for cancer targeting and treatment: Synthesis, characterization, in-vitro and in-vivo evaluation of therapeutic efficacy
Polymeric materials are in the epicenter of scientific research the last decade and have been used in a range of pharmaceutical and biological applications. Multifunctional polymeric materials are capable targeting agents, which can be used as controlled drug release vehicles for the enhancement of therapeutic efficacy, as well as for diagnostic purposes. A newer generation of these smart polymeric entities constitutes of smart nanocontainers (NCs), which can navigate the drug to specific areas by avoiding random distribution, and thus resulting in drug toxicity reduction. The combination of pH, thermo and redox sensitivity of the multi stimuli NCs can help to achieve specific release of the drug in the tumor area, where these sensitivity parameters can be observed. Hollow polymeric multi stimuli fluorescent tNCs based on N-(2-Hydroxypropyl)methacrylamide (HPMA) were successfully functionalized with a specific targeting moiety; folic acid, and then characterized morphologically, by scanning electron and transmission electron microscopy, as well as structurally, by Fourier-transform infrared spectroscopy. Their targeting mechanism was investigated in vitro in cervical cancer cell lines and in vivo in tumor bearing mice. According to our results the folic acid functionalized NCs targeted HeLa cells’ surface within the first 30 min of treatment. Human tumor xenografted mice (nonobese diabetic/severe combined immunodeficient) were injected with folate functionalized NCs and their tumor uptake was estimated by γ-imaging at about 3.5%. The targeting efficiency of the folate functionalized NCs was investigated directly in vivo by γ-imaging and indirectly by a tumor efficacy protocol.
Efthimiadou,Lelovas,Fragogeorgi,Boukos,Balafas,Loudos,Kostomitsopoulos,Theodosiou,Tziveleka,Kordas
(2020/01/13)

COMPOSITIONS AND METHODS OF MANUFACTURING STAR POLYMERS FOR LIGAND DISPLAY AND/OR DRUG DELIVERY
A star polymer of formula O[P1]-([X]-A[P2]-[Z]-[P3])n where O is a core; A is a polymer arm attached to the core; X is a linker molecule between the core and the polymer arm; Z is a linker molecule between the end of the polymer arm and P3; P1, P2 and P3 are each independently one or more pharmaceutically active compounds that act extracellularly or intracellularly, n is an integer number; [ ] denotes that the group is optional; and at least one of P1, P2 or P3 is present.
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Paragraph 00422-00424

(2020/10/28)

Overcoming resistance to rituximab in relapsed non-Hodgkin lymphomas by antibody-polymer drug conjugates actively targeted by anti-CD38 daratumumab
B-cell non-Hodgkin lymphomas (B-NHL) represent the most common type of hematologic malignancies in the Western hemisphere. The therapy of all B-NHL is based on the combination of different genotoxic cytostatics and anti-CD20 monoclonal antibody (mAb) rituximab. Unfortunately, many patients relapse after the mentioned front-line treatment approaches. The therapy of patients with relapsed/refractory (R/R) B-NHL represents an unmet medical need. We designed, developed and tested novel actively targeted hybrid mAb-polymer-drug conjugate (APDC) containing anti-CD20, anti-CD38 or anti-CD19 mAbs. Biocompatible copolymers based on N-(2-hydroxypropyl)methacrylamide (HPMA) with cytostatic agent doxorubicin attached via stimuli-sensitive hydrazone bond were employed for the mAb grafting. Anti-lymphoma efficacy of the APDC nanotherapeutics was evaluated in vivo on a panel of three patient-derived lymphoma xenografts derived from two patients with R/R B-NHL and one patient with so far untreated B-NHL. In both PDX models derived from patients with R/R B-NHL, the targeting with anti-CD38 antibody daratumumab demonstrated highly improved anti-lymphoma efficacy compared to the targeting with anti-CD20 rituximab, two experimental anti-CD19 antibodies and non-targeted controls. The results represent a proof-of-concept of a new algorithm of personalized anti-tumor therapy based on highly innovative APDC biomaterials.
Helman, Karel,Klener, Pavel,Mavis, Cory,Etrych, Tomá?,Janou?ková, Olga,Lidicky, Ond?ej,Machová, Daniela,Pokorná, Eva,Vo?ková, Petra
p. 160 - 170
(2020/09/07)

Biotinylated HPMA centered polymeric nanoparticles for Bortezomib delivery
Bortezomib (BTZ) is a proteasome inhibitor as approved by US FDA for the treatment of multiple myeloma. It exhibits significant anti-cancer properties, against solid tumors; but lacks aqueous solubility, chemical stability which hinders its successful formulation development. The present study is an attempt to deliver BTZ using N-(2-hydroxypropyl) methacrylamide (HPMA) based copolymeric conjugates and biotinylated PNPs in an effective manner. Study describes a systematic synthetic pathway to synthesize functional polymeric conjugates such as HPMA-Biotin (HP-BT) HPMA-Polylactic acid (HPLA) and HPMA-PLA-Biotin (HPLA-BT) followed by exhaustive characterization both spectroscopically and microscopically. Our strategy yielded polymeric nanoparticles (PNPs) of narrow size range of 199.7 ± 1.32 nm. Release studies were performed at pH 7.4 and 5.6. PNPs were 2-folds less hemolytic (p 50 value of these PNPs was 56.06 ± 0.12 nM, which was approximately two folds less than BTZ (p 0 t-∞) of DL-HPLA-BT PNPs (drug loaded) than BTZ with an improved half-life. Overall the developed PNPs led to the improved and effective BTZ delivery.
Ajazuddin,Gupta, Umesh,Nakhate, Kartik T.,Rani, Sarita,Sahoo, Rakesh K.
(2020/03/10)

Polyvalent Diazonium Polymers Provide Efficient Protection of Oncolytic Adenovirus Enadenotucirev from Neutralizing Antibodies while Maintaining Biological Activity in Vitro and in Vivo
Oncolytic viruses offer many advantages for cancer therapy when administered directly to confined solid tumors. However, the systemic delivery of these viruses is problematic because of the host immune response, undesired interactions with blood components, and inherent targeting to the liver. Efficacy of systemically administered viruses has been improved by masking viral surface proteins with polymeric materials resulting in modulation of viral pharmacokinetic profile and accumulation in tumors in vivo. Here we describe a new class of polyvalent reactive polymer based on poly(N-(2-hydroxypropyl)methacrylamide) (polyHPMA) with diazonium reactive groups and their application in the modification of the chimeric group B oncolytic virus enadenotucirev (EnAd). A series of six copolymers with different chain lengths and density of reactive groups was synthesized and used to coat EnAd. Polymer coating was found to be extremely efficient with concentrations as low as 1 mg/mL resulting in complete (>99%) ablation of neutralizing antibody binding. Coating efficiency was found to be dependent on both chain length and reactive group density. Coated viruses were found to have reduced transfection activity both in vitro and in vivo, with greater protection against neutralizing antibodies resulting in lower transgene production. However, in the presence of neutralizing antibodies, some in vivo transgene expression was maintained for coated virus compared to the uncoated control. The decrease in transgene expression was found not to be solely due to lower cellular uptake but due to reduced unpackaging of the virus within the cells and reduced replication, indicating that the polymer coating does not cause permanent inactivation of the virus. These data suggest that virus activity may be modulated by the appropriate design of coating polymers while retaining protection against neutralizing antibodies.
Francini, Nora,Purdie, Laura,Mantovani, Giuseppe,Alexander, Cameron,Cochrane, Daniel,Illingworth, Sam,Fisher, Kerry,Seymour, Leonard W.,Spain, Sebastian G.
p. 1244 - 1257
(2019/05/11)

Impact of Polymer-TLR-7/8 Agonist (Adjuvant) Morphology on the Potency and Mechanism of CD8 T Cell Induction
Small molecule Toll-like receptor-7 and -8 agonists (TLR-7/8a) can be used as vaccine adjuvants to induce CD8 T cell immunity but require formulations that prevent systemic toxicity and focus adjuvant activity in lymphoid tissues. Here, we covalently attached TLR-7/8a to polymers of varying composition, chain architecture and hydrodynamic behavior (～300 nm submicrometer particles, ～10 nm micelles and ～4 nm flexible random coils) and evaluated how these parameters of polymer-TLR-7/8a conjugates impact adjuvant activity in vivo. Attachment of TLR-7/8a to any of the polymer compositions resulted in a nearly 10-fold reduction in systemic cytokines (toxicity). Moreover, both lymph node cytokine production and the magnitude of CD8 T cells induced against protein antigen increased with increasing polymer-TLR-7/8a hydrodynamic radius, with the submicrometer particle inducing the highest magnitude responses. Notably, CD8 T cell responses induced by polymer-TLR-7/8a were dependent on CCR2+ monocytes and IL-12, whereas responses by a small molecule TLR-7/8a that unexpectedly persisted in vaccine-site draining lymph nodes (T1/2 = 15 h) had less dependence on monocytes and IL-12 but required Type I IFNs. This study shows how modular properties of synthetic adjuvants can be chemically programmed to alter immunity in vivo through distinct immunological mechanisms.
Lynn, Geoffrey M.,Chytil, Petr,Francica, Joseph R.,Lagová, Anna,Kueberuwa, Gray,Ishizuka, Andrew S.,Zaidi, Neeha,Ramirez-Valdez, Ramiro A.,Blobel, Nicolas J.,Baharom, Faezzah,Leal, Joseph,Wang, Amy Q.,Gerner, Michael Y.,Etrych, Tomá?,Ulbrich, Karel,Seymour, Leonard W.,Seder, Robert A.,Laga, Richard
p. 854 - 870
(2019/02/15)

HPMA-PLGA Based Nanoparticles for Effective In Vitro Delivery of Rifampicin
Purpose: Tuberculosis (TB) chemotherapy witnesses some major challenges such as poor water-solubility and bioavailability of drugs that frequently delay the treatment. In the present study, an attempt to enhance the aqueous solubility of rifampicin (RMP) was made via co-polymeric nanoparticles approach. HPMA (N-2-hydroxypropylmethacrylamide)-PLGA based polymeric nanoparticulate system were prepared and evaluated against Mycobacterium tuberculosis (MTB) for sustained release and bioavailability of RMP to achieve better delivery. Methodology: HPMA-PLGA nanoparticles (HP-NPs) were prepared by modified nanoprecipitation technique, RMP was loaded in the prepared NPs. Characterization for particle size, zeta potential, and drug-loading capacity was performed. Release was studied using membrane dialysis method. Results: The average particles size, zeta potential, polydispersity index of RMP loaded HPMA-PLGA-NPs (HPR-NPs) were 260.3 ± 2.21?nm, ?6.63 ± 1.28?mV, and 0.303 ± 0.22, respectively. TEM images showed spherical shaped NPs with uniform distribution without any cluster formation. Entrapment efficiency and drug loading efficiency of HPR-NPs were found to be 76.25 ± 1.28%, and 26.19 ± 2.24%, respectively. Kinetic models of drug release including Higuchi and Korsmeyer-peppas demonstrated sustained release pattern. Interaction studies with human RBCs confirmed that RMP loaded HP-NPs are less toxic in this model than pure RMP with (p 0.05). Conclusions: The pathogen inhibition studies revealed that developed HPR-NPs were approximately four times more effective with (p 0.05) than pure drug against sensitive Mycobacterium tuberculosis (MTB) stain. It may be concluded that HPR-NPs holds promising potential for increasing solubility and bioavailability of RMP.
Rani, Sarita,Gothwal, Avinash,Pandey, Pawan K.,Chauhan, Devendra S.,Pachouri, Praveen K.,Gupta, Umesh D.,Gupta, Umesh
(2018/12/11)

Polymer Cancerostatics Targeted by Recombinant Antibody Fragments to GD2-Positive Tumor Cells
A water-soluble polymer cancerostatic actively targeted against cancer cells expressing a disialoganglioside antigen GD2 was designed, synthesized and characterized. A polymer conjugate of an antitumor drug doxorubicin with a N-(2-hydroxypropyl)methacrylamide-based copolymer was specifically targeted against GD2 antigen-positive tumor cells using a recombinant single chain fragment (scFv) of an anti-GD2 monoclonal antibody. The targeting protein ligand was attached to the polymer-drug conjugate either via a covalent bond between the amino groups of the protein using a traditional nonspecific aminolytic reaction with a reactive polymer precursor or via a noncovalent but highly specific interaction between bungarotoxin covalently linked to the polymer and the recombinant scFv modified with a C-terminal bungarotoxin-binding peptide. The GD2 antigen binding activity and GD2-specific cytotoxicity of the targeted noncovalent polymer-scFv complex proved to be superior to the covalent polymer-scFv conjugate.
Pola, Robert,Král, Vlastimil,Filippov, Sergey K.,Kaberov, Leonid,Etrych, Tomá?,Sieglová, Irena,Sedlá?ek, Juraj,Fábry, Milan,Pechar, Michal
p. 412 - 421
(2019/01/18)

Based on N - (2 - hydroxypropyl) methacrylamide polymer nanometer grain and its preparation method
The invention discloses an N-(2-hydroxypropyl) methacrylamide polymer based nanoparticles capable of overcoming a mucus barrier and a preparation method thereof. The nanoparticles consist of nucleuses and shells, wherein the kernels are a nanometer compound prepared from a biocompatible carrier material and active ingredients, and the shells are an HPMA polymer and its derivatives.
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Paragraph 0057; 0058

(2019/02/26)

Cyclic Peptide-Polymer Nanotubes as Efficient and Highly Potent Drug Delivery Systems for Organometallic Anticancer Complexes
Functional drug carrier systems have potential for increasing solubility and potency of drugs while reducing side effects. Complex polymeric materials, particularly anisotropic structures, are especially attractive due to their long circulation times. Here, we have conjugated cyclic peptides to the biocompatible polymer poly(2-hydroxypropyl methacrylamide) (pHPMA). The resulting conjugates were functionalized with organoiridium anticancer complexes. Small angle neutron scattering and static light scattering confirmed their self-assembly and elongated cylindrical shape. Drug-loaded nanotubes exhibited more potent antiproliferative activity toward human cancer cells than either free drug or the drug-loaded polymers, while the nanotubes themselves were nontoxic. Cellular accumulation studies revealed that the increased potency of the conjugate appears to be related to a more efficient mode of action rather than a higher cellular accumulation of iridium.
Larnaudie, Sophie C.,Brendel, Johannes C.,Romero-Canelón, Isolda,Sanchez-Cano, Carlos,Catrouillet, Sylvain,Sanchis, Joaquin,Coverdale, James P. C.,Song, Ji-Inn,Habtemariam, Abraha,Sadler, Peter J.,Jolliffe, Katrina A.,Perrier, Sébastien
p. 239 - 247
(2018/01/17)

Native Chemical Ligation for Cross-Linking of Flower-Like Micelles
In this study, native chemical ligation (NCL) was used as a selective cross-linking method to form core-cross-linked thermosensitive polymeric micelles for drug delivery applications. To this end, two complementary ABA triblock copolymers having polyethylene glycol (PEG) as midblock were synthesized by atom transfer radical polymerization (ATRP). The thermosensitive poly isopropylacrylamide (PNIPAM) outer blocks of the polymers were copolymerized with either N-(2-hydroxypropyl)methacrylamide-cysteine (HPMA-Cys), P(NIPAM-co-HPMA-Cys)-PEG-P(NIPAM-co-HPMA-Cys) (PNC) or N-(2-hydroxypropyl)methacrylamide-ethylthioglycolate succinic acid (HPMA-ETSA), P(NIPAM-co-HPMA-ETSA)-PEG-P(NIPAM-co-HPMA-ETSA) (PNE). Mixing of these polymers in aqueous solution followed by heating to 50 °C resulted in the formation of thermosensitive flower-like micelles. Subsequently, native chemical ligation in the core of micelles resulted in stabilization of the micelles with a Z-average of 65 nm at body temperature. Decreasing the temperature to 10 °C only affected the size of the micelles (increased to 90 nm) but hardly affected the polydispersity index (PDI) and aggregation number (Nagg) confirming covalent stabilization of the micelles by NCL. CryoTEM images showed micelles with an uniform spherical shape and dark patches close to the corona of micelles were observed in the tomographic view. The dark patches represent more dense areas in the micelles which coincide with the higher content of HPMA-Cys/ETSA close to the PEG chain revealed by the polymerization kinetics study. Notably, this cross-linking method provides the possibility for conjugation of functional molecules either by using the thiol moieties still present after NCL or by simply adjusting the molar ratio between the polymers (resulting in excess cysteine or thioester moieties) during micelle formation. Furthermore, in vitro cell experiments demonstrated that fluorescently labeled micelles were successfully taken up by HeLa cells while cell viability remained high even at high micelle concentrations. These results demonstrate the potential of these micelles for drug delivery applications.
Najafi, Marzieh,Kordalivand, Neda,Moradi, Mohammad-Amin,Van Den Dikkenberg, Joep,Fokkink, Remco,Friedrich, Heiner,Sommerdijk, Nico A. J. M.,Hembury, Mathew,Vermonden, Tina
p. 3766 - 3775
(2018/09/06)

Self-Assembled Thermoresponsive Polymeric Nanogels for 19F MR Imaging
Magnetic resonance imaging using fluorinated contrast agents (19F MRI) enables to achive highcontrast in images due to the negligible fluorine background in living tissues. In this pilot study, we developed new biocompatible, temperature-responsive, and easily synthesized polymeric nanogels containing a sufficient concentration of magnetically equivalent fluorine atoms for 19F MRI purposes. The structure of the nanogels is based on amphiphilic copolymers containing two blocks, a hydrophilic poly[N-(2-hydroxypropyl)methacrylamide] (PHPMA) or poly(2-methyl-2-oxazoline) (PMeOx) block, and a thermoresponsive poly[N(2,2difluoroethyl)acrylamide] (PDFEA) block. The thermoresponsive properties of the PDFEA block allow us to control the process of nanogel self-assembly upon its heating in an aqueous solution. Particle size depends on the copolymer composition, and the most promising copolymers with longer thermoresponsive blocks form nanogels of suitable size for angiogenesis imaging or the labeling of cells (approximately 120 nm). The in vitro 19F MRI experiments reveal good sensitivity of the copolymer contrast agents, while the nanogels were proven to be noncytotoxic for several cell lines.
Kolouchova, Kristyna,Sedlacek, Ondrej,Jirak, Daniel,Babuka, David,Blahut, Jan,Kotek, Jan,Vit, Martin,Trousil, Jiri,Konefa?, Rafa?,Janouskova, Olga,Podhorska, Bohumila,Slouf, Miroslav,Hruby, Martin
p. 3515 - 3524
(2018/07/30)

Conjugated and Entrapped HPMA-PLA Nano-Polymeric Micelles Based Dual Delivery of First Line Anti TB Drugs: Improved and Safe Drug Delivery against Sensitive and Resistant Mycobacterium Tuberculosis
Purpose: First line antiTB drugs have several physical and toxic manifestations which limit their applications. RIF is a hydrophobic drug and has low water solubility and INH is hepatotoxic. The main objective of the study was to synthesize, characterize HPMA-PLA co-polymeric micelles for the effective dual delivery of INH and RIF. Methods: HPMA-PLA co-polymer and HPMA-PLA-INH (HPI) conjugates were synthesized and characterized by FT-IR and 1H–NMR spectroscopy. Later on RIF loaded HPMA-PLA-INH co-polymeric micelles (PMRI) were formulated and characterized for size, zeta potential and surface morphology (SEM, TEM) as well as critical micellar concentration. The safety was assessed through RBC’s interaction study. The prepared PMRI were evaluated through MABA assay against sensitive and resistant strains of M. Tuberculosis. Results: Size, zeta and entrapment efficiency for RIF loaded HPMA-PLA-INH polymeric micelles (PMRI) was 87.64?±?1.98?nm, ?19?±?1.93?mV and 97.2?±?1.56%, respectively. In vitro release followed controlled and sustained delivery pattern. Sustained release was also supported by release kinetics. Haemolytic toxicity of HPI and PMRI was 8.57 and 7.05% (p??0.01, INH Vs PMRI; p??0.0001, RIF Vs PMRI), respectively. MABA assay (cytotoxicity) based MIC values of PMRI formulation was observed as ≥0.0625 and ≥0.50?μg/mL (for sensitive and resistant strain). The microscopic analysis further confirmed that the delivery approach was effective than pure drugs. Conclusions: RIF loaded and INH conjugated HPMA-PLA polymeric micelles (PMRI) were more effective against sensitive and resistant M tuberculosis. The developed approach can lead to improved patient compliance and reduced dosing in future, offering improved treatment of tuberculosis.
Upadhyay, Seema,Khan, Iliyas,Gothwal, Avinash,Pachouri, Praveen K.,Bhaskar,Gupta, Umesh D.,Chauhan, Devendra S.,Gupta, Umesh
p. 1944 - 1955
(2017/08/07)

HYDROPHILIC POLYMER CONJUGATE WITH MULTIPLE ANTIVIRAL AGENTS FOR TREATING A VIRAL INFECTION
The present invention relates to a hydrophilic polymer conjugate comprising multiple antiviral agents for treating viral infections. The present invention also relates to methods of treating viral infections, in particular, human immunodeficiency virus (HIV) infection, by administration of a hydrophilic polymer conjugate comprising multiple antiviral agents. The polymer conjugates may be useful in combination therapy for the treatment of HIV.
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Page/Page column 70-71

(2018/01/17)

IBodies: Modular synthetic antibody mimetics based on hydrophilic polymers decorated with functional moieties
Antibodies are indispensable tools for biomedicine and anticancer therapy. Nevertheless, their use is compromised by high production costs, limited stability, and difficulty of chemical modification. The design and preparation of synthetic polymer conjugates capable of replacing antibodies in biomedical applications such as ELISA, flow cytometry, immunocytochemistry, and immunoprecipitation is reported. The conjugates, named "iBodies", consist of an HPMA copolymer decorated with low-molecular-weight compounds that function as targeting ligands, affinity anchors, and imaging probes. We prepared specific conjugates targeting several proteins with known ligands and used these iBodies for enzyme inhibition, protein isolation, immobilization, quantification, and live-cell imaging. Our data indicate that this highly modular and versatile polymer system can be used to produce inexpensive and stable antibody substitutes directed toward virtually any protein of interest with a known ligand.
?ácha, Pavel,Knedlík, Tomá?,Schimer, Ji?í,Tykvart, Jan,Parolek, Jan,Navrátil, Václav,Dvo?áková, Petra,Sedlák, Franti?ek,Ulbrich, Karel,Strohalm, Ji?í,Majer, Pavel,?ubr, Vladimír,Konvalinka, Jan
supporting information
p. 2356 - 2360
(2016/02/18)

Indium-based and iodine-based labeling of HPMA copolymer-epirubicin conjugates: Impact of structure on the in vivo fate
Recently, we developed 2nd generation backbone degradable N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer-drug conjugates which contain enzymatically cleavable sequences (GFLG) in both polymeric backbone and side-chains. This design allows using polymeric carriers with molecular weights above renal threshold without impairing their biocompatibility, thereby leading to significant improvement in therapeutic efficacy. For example, 2nd generation HPMA copolymer-epirubicin (EPI) conjugates (2P-EPI) demonstrated complete tumor regression in the treatment of mice bearing ovarian carcinoma. To obtain a better understanding of the in vivo fate of this system, we developed a dual-labeling strategy to simultaneously investigate the pharmacokinetics and biodistribution of the polymer carrier and drug EPI. First, we synthesized two different types of dual-radiolabeled conjugates, including 1) 111In-2P-EPI-125I (polymeric carrier 2P was radiolabeled with 111In and drug EPI with 125I), and 2) 125I-2P-EPI-111In (polymeric carrier 2P was radiolabeled with 125I and drug EPI with 111In). Then, we compared the pharmacokinetics and biodistribution of these two dual-labeled conjugates in female nude mice bearing A2780 human ovarian carcinoma. There was no significant difference in the blood circulation between polymeric carrier and payload; the carriers (111In-2P and 125I-2P) showed similar retention of radioactivity in both tumor and major organs except kidney. However, compared to 111In-labeled payload EPI, 125I-labeled EPI showed lower radioactivity in normal organs and tumor at 48 h and 144 h after intravenous administration of conjugates. This may be due to different drug release rates resulting from steric hindrance to the formation of enzyme-substrate complex as indicated by cleavage experiments with lysosomal enzymes (Tritosomes). A slower release rate of EPI(DTPA)111In than EPI(Tyr)125I was observed. It may be also due to in vivo catabolism and subsequent iodine loss as literature reported. Nevertheless, tumor-to-tissue uptake ratios of both radionuclides were comparable, indicating that drug-labeling strategy does not affect the tumor targeting ability of HPMA copolymer conjugates.
Zhang, Libin,Zhang, Rui,Yang, Jiyuan,Wang, Jiawei,Kope?ek, Jind?ich
p. 306 - 318
(2016/07/06)

METHOD FOR PRODUCING 2-HYDROXYALKYL (METH) ACRYLAMIDE
PROBLEM TO BE SOLVED: To provide a method for producing N-(2-hydroxyalkyl)(meth) acrylamide. SOLUTION: The reaction of a ketimine compound or an aldimine compound of 2-aminoalkyl (meth) acrylate with water makes it possible to produce N-(2-hydroxyalkyl)(meth) acrylamide with high yields. SELECTED DRAWING: None COPYRIGHT: (C)2017,JPOandINPIT
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Paragraph 0038

(2017/06/02)

Role of Polymer Architecture on the Activity of Polymer-Protein Conjugates for the Treatment of Accelerated Bone Loss Disorders
Polymers of similar molecular weights and chemical constitution but varying in their macromolecular architectures were conjugated to osteoprotegerin (OPG) to determine the effect of polymer topology on protein activity in vitro and in vivo. OPG is a protein that inhibits bone resorption by preventing the formation of mature osteoclasts from the osteoclast precursor cell. Accelerated bone loss disorders, such as osteoporosis, rheumatoid arthritis, and metastatic bone disease, occur as a result of increased osteoclastogenesis, leading to the severe weakening of the bone. OPG has shown promise as a treatment in bone disorders; however, it is rapidly cleared from circulation through rapid liver uptake, and frequent, high doses of the protein are necessary to achieve a therapeutic benefit. We aimed to improve the effectiveness of OPG by creating OPG-polymer bioconjugates, employing reversible addition-fragmentation chain transfer polymerization to create well-defined polymers with branching densities varying from linear, loosely branched to densely branched. Polymers with each of these architectures were conjugated to OPG using a "grafting-to" approach, and the bioconjugates were characterized by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The OPG-polymer bioconjugates showed retention of activity in vitro against osteoclasts, and each bioconjugate was shown to be nontoxic. Preliminary in vivo studies further supported the nontoxic characteristics of the bioconjugates, and measurement of the bone mineral density in rats 7 days post-treatment via peripheral quantitative computed tomography suggested a slight increase in bone mineral density after administration of the loosely branched OPG-polymer bioconjugate. (Chemical Equation Presented).
Tucker, Bryan S.,Stewart, Jon D.,Aguirre, J. Ignacio,Holliday, L. Shannon,Figg, C. Adrian,Messer, Jonathan G.,Sumerlin, Brent S.
p. 2374 - 2381
(2015/08/19)

Thermoresponsive Polymer Micelles as Potential Nanosized Cancerostatics
An effective chemotherapy for neoplastic diseases requires the use of drugs that can reach the site of action at a therapeutically efficacious concentration and maintain it at a constant level over a sufficient period of time with minimal side effects. Currently, conjugates of high-molecular-weight hydrophilic polymers or biocompatible nanoparticles with stimuli-releasable anticancer drugs are considered to be some of the most promising systems capable of fulfilling these criteria. In this work, conjugates of thermoresponsive diblock copolymers with the covalently bound cancerostatic drug pirarubicin (PIR) were synthesized as a reversible micelle-forming drug delivery system combining the benefits of the above-mentioned carriers. The diblock copolymer carriers were composed of hydrophilic poly[N-(2-hydroxypropyl)methacrylamide]-based block containing a small amount (～5 mol %) of comonomer units with reactive hydrazide groups and a thermoresponsive poly[2-(2-methoxyethoxy)ethyl methacrylate] block. PIR was attached to the hydrophilic block of the copolymer through the pH-sensitive hydrazone bond designed to be stable in the bloodstream at pH 7.4 but to be degraded in an intratumoral/intracellular environment at pH 5-6. The temperature-induced conformation change of the thermoresponsive block (coil-globule transition), followed by self-assembly of the copolymer into a micellar structure, was controlled by the thermoresponsive block length and PIR content. The cytotoxicity and intracellular transport of the conjugates as well as the release of PIR from the conjugates inside the cells, followed by its accumulation in the cell nuclei, were evaluated in vitro using human colon adenocarcinoma (DLD-1) cell lines. It was demonstrated that the studied conjugates have a great potential to become efficacious in vivo pharmaceuticals. (Figure Presented).
Laga, Richard,Janou?ková, Olga,Ulbrich, Karel,Pola, Robert,Bla?ková, Jana,Filippov, Sergey K.,Etrych, Tomá?,Pechar, Michal
p. 2493 - 2505
(2015/08/19)

Synthesis of Poly[ N -(2-hydroxypropyl)methacrylamide] conjugates of inhibitors of the ABC transporter that overcome multidrug resistance in doxorubicin-resistant P388 cells in vitro
The effects of novel polymeric therapeutics based on water-soluble N-(2-hydroxypropyl)methacrylamide copolymers (P(HPMA)) bearing the anticancer drug doxorubicin (Dox), an inhibitor of ABC transporters, or both, on the viability and the proliferation of the murine monocytic leukemia cell line P388 (parental cell line) and its doxorubicin-resistant subline P388/MDR were studied in vitro. The inhibitor derivatives 5-methyl-4-oxohexanoyl reversin 121 (MeOHe-R121) and 5-methyl-4-oxohexanoyl ritonavir ester (MeOHe-RIT), showing the highest inhibitory activities, were conjugated to the P(HPMA) via the biodegradable pH-sensitive hydrazone bond, and the ability of these conjugates to block the ATP driven P-glycoprotein (P-gp) efflux pump was tested. The P(HPMA) conjugate P-Ahx-NH-N=MeOHe-R121 showed a dose-dependent increase in the ability to sensitize the P388/MDR cells to Dox from 1.5 to 24μM, and achieved an approximately 50-fold increase in sensitization at 24μM. The P(HPMA) conjugate P-Ahx-NH-N=MeOHe-RIT showed moderate activity at 6μM (～10 times higher sensitization) and increased sensitization by 50-fold at 12μM. The cytostatic activity of the P(HPMA) conjugate P-Ahx-NH-N=MeOHe-R121(Dox) containing Dox and the P-gp inhibitor MeOHe-R121, both bound via hydrazone bonds to the P(HPMA) carrier, was almost 30 times higher than that of the conjugate P-Ahx-NH-N=Dox toward the P388/MDR cells in vitro. A similar result was observed for P-Ahx-NH-N=MeOHe-RIT(Dox), which exhibited almost 10 times higher cytostatic activity than P-Ahx-NH-N=Dox.
?ubr,Sivák,Koziolová,Braunová,Pechar,Strohalm,Kabe?ová,?íhová,Ulbrich,Ková?
p. 3030 - 3043
(2014/11/07)

Inhibition of protein and cell attachment on materials generated from N -(2-hydroxypropyl) acrylamide
Effective control over biointerfacial interactions is essential for a broad range of biomedical applications. At this point in time, only a relatively small range of radically polymerizable monomers have been described that are able to generate low fouling polymer materials and surfaces. The most important examples that have been successfully used in the context of the reduction of nonspecific protein adsorption and subsequent cell attachment include PEG-based monomers such as poly(ethylene glycol) methacrylate (PEGMA), zwitterionic monomers such as 2-methacryloyloxyethyl phosphorylcholine and noncharged monomers such as acrylamide and N-(2-hydroxypropyl) methacrylamide (HPMAm). However, issues such as oxidative degradation and poor polymerization characteristics limit the applicability of most of these candidates. Here we have synthesized the monomer N-(2-hydroxypropyl) acrylamide (HPAm), examined its polymerization kinetics and evaluated its suitability for RAFT mediated polymerization in comparison to HPMAm. We also synthesized hydrogels using HPMAm and HPAm and evaluated the ability of HPAm polymers to occlude protein adsorption and cell attachment. In RAFT-controlled polymerization, much faster (8×) polymerization was observed for HPAm relative to HPMAm and better control was achieved over the molecular weight distribution. The performance of hydrogels prepared from HPAm in the prevention of protein adsorption and cellular attachment was equivalent to or better than that observed for materials made from HPMAm and PEG. These results open the door for HPAm based polymers in applications where effective control over biointerfacial interactions is required.
Fairbanks, Benjamin D.,Thissen, Helmut,Maurdev, George,Pasic, Paul,White, Jacinta F.,Meagher, Laurence
p. 3259 - 3266
(2015/01/08)

Synthesis of click-reactive HPMA copolymers using RAFT polymerization for drug delivery applications
This study describes a versatile strategy combining reversible addition fragmentation transfer (RAFT) polymerization and click chemistry to synthesize well-defined, reactive copolymers of N-(2-hydroxypropyl)methacrylamide (HPMA) for drug delivery applications. A novel azide containing monomer N-(3-azidopropyl)methacrylamide (AzMA) was synthesized and copolymerized with HPMA using RAFT polymerization to provide p(HPMA-co-AzMA) copolymers with high control of molecular weight (～10-54 kDa) and polydispersity (≤1.06). The utility of the side-chain azide functionality by Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) was demonstrated by efficient conjugation (up to 92%) of phosphocholine, a near infrared dye, and poly(ethylene glycol) (PEG) with different substitution degrees, either alone or in combination. This study introduces a novel and versatile method to synthesize well-defined click-reactive HPMA copolymers for preparing a panel of bioconjugates with different functionalities needed to systemically evaluate and tune the biological performance of polymer-based drug delivery. Copyright
Ebbesen, Morten F.,Schaffert, David H.,Crowley, Michael L.,Oupicky, David,Howard, Kenneth A.
p. 5091 - 5099
(2013/11/06)

Polymer therapeutics with a coiled coil motif targeted against murine BCL1 leukemia
The specificity of polymer conjugates based on N-(2-hydroxypropyl) methacrylamide (HPMA) bearing cytostatic drugs for cancer cells could be significantly increased by the incorporation of a suitable targeting ligand, such as a monoclonal antibody (mAb). However, direct binding of the protein to the polymer carrier could cause considerable problems, such as decreasing the binding capacity of mAb to its target. Here, we introduce a novel strategy of joining a targeting moiety to a polymeric conjugate with cytostatic drug. The scFv of B1 mAb (specific for BCL1 leukemia cells) was tagged with peptide K ((VAALKEK)4). Peptide E ((VAALEKE)4), which forms a stable coiled coil structure heterodimer with peptide K, was assembled with the HPMA copolymers bearing doxorubicin. Such targeted polymeric conjugates possess very selective and high binding activity toward BCL1 cells. Similarly, targeted polymeric conjugates exert approximately 100 times higher cytostatic activity toward BCL1 cells in comparison to nontargeted conjugates in vitro. At the same time, the conjugates have comparable and rather low cytostatic activity for 38C13 cells, which are used as a negative control, in vitro.
Pola, Robert,Laga, Richard,Ulbrich, Karel,Sieglová, Irena,Král, Vlastimil,Fábry, Milan,Kabe?ová, Martina,Ková?, Marek,Pechar, Michal
p. 881 - 889
(2013/05/09)

Ir(III)-catalyzed mild C-H amidation of arenes and alkenes: An efficient usage of acyl azides as the nitrogen source
Reported herein is the development of the Ir(III)-catalyzed direct C-H amidation of arenes and alkenes using acyl azides as the nitrogen source. This procedure utilizes an in situ generated cationic half-sandwich iridium complex as a catalyst. The reaction takes place under very mild conditions, and a broad range of sp2 C-H bonds of chelate group-containing arenes and olefins are smoothly amidated with acyl azides without the intervention of the Curtius rearrangement. Significantly, a wide range of reactants of aryl-, aliphatic-, and olefinic acyl azides were all efficiently amidated with high functional group tolerance. Using the developed approach, Z-enamides were readily accessed with a complete control of regio- and stereoselectivity. The developed direct amidation proceeds in the absence of external oxidants and releases molecular nitrogen as a single byproduct, thus offering an environmentally benign process with wide potential applications in organic synthesis and medicinal chemistry.
Ryu, Jaeyune,Kwak, Jaesung,Shin, Kwangmin,Lee, Donggun,Chang, Sukbok
supporting information
p. 12861 - 12868
(2013/09/23)

HPMA copolymer-doxorubicin conjugates: The effects of molecular weight and architecture on biodistribution and in vivo activity
The molecular weight and molecular architecture of soluble polymer drug carriers significantly influence the biodistribution and anti-tumour activities of their doxorubicin (DOX) conjugates in tumour-bearing mice. Biodistribution of N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer-DOX conjugates of linear and star architectures were compared in EL4 T-cell lymphoma-bearing mice. Biodistribution, including tumour accumulation, and anti-tumour activity of the conjugates strongly depended on conjugate molecular weight (MW), polydispersity, hydrodynamic radius (Rh) and molecular architecture. With increasing MW, renal clearance decreased, and the conjugates displayed extended blood circulation and enhanced tumour accumulation. The linear conjugates with flexible polymer chains were eliminated by kidney clearance more quickly than the highly branched star conjugates with comparable MWs. Interestingly, the data suggested different mechanisms of renal filtration for star and linear conjugates. Only star conjugates with MWs below 50,000 g.mo -1 were removed by kidney filtration, while linear polymer conjugates with MWs near 70,000 g.mol- 1, exceeding the generally accepted limit for renal elimination, were detected in the urine 36-96 h after injection. Additionally, survival of tumour-bearing mice was strongly dependent on molecular weight and polymer conjugate architecture. Treatment of mice with the lower MW conjugate at a dose of 10 mg DOX eq./kg resulted in 12% long-term surviving animals, while treatment with the corresponding star conjugate enabled 75% survival of animals.
Etrych, Tomas,Subr, Vladimir,Strohalm, Jiri,Sirova, Milada,Rihova, Blanka,Ulbrich, Karel
p. 346 - 354
(2013/02/23)

Removable nanocoatings for siRNA polyplexes
To assist in overcoming the in-herent instability of nucleic acid-containing polyplexes in physiological solutions, we have here set out to develop removable nanocoatings for modifying the surface of siRNA-based nanoparticles. Here, N-(2-hydroxypropyl)methacrylamide (HPMA) based copolymers containing carbonylthiazolidine-2-thione (TT) reactive groups in their side chains bound via disulfide spacers to the polymeric backbone were synthesized, and these copolymers were used to coat the surface of polyplexes formed by the self-assembly of anti-Luciferase siRNA with the polycations polyethylene imine (PEI) and poly(HPMA)-grafted poly(l-lysine) (GPL). The coating process was monitored by analyzing changes in the weight-average molecular weight (M w), the hydrodynamic radius (Rh), and the zeta-potential (ζ) of the polyplexes, using both static (SLS) and dynamic (DLS) light scattering methods. The outlined methods resulted in the attachment of, on average, 28 polymer molecules to the surface of the polyplexes, forming a ～5-nm-thick hydrophilic stealth coating. Initial efforts to develop RGD-targeted coated polyplexes are also described. Atomic force microscopy (AFM) showed an angular polyplex structure and confirmed the narrow size distribution of the coated nanoparticles. The stability of the polymer-coated and uncoated polyplexes was evaluated by gel electrophoresis and by turbidity measurements, and it was found that modifying the surface of the siRNA-containing polyplexes substantially improved their stability in physiological solutions. Using polymer-coated GPL-based polyplexes containing anti-Luciferase siRNA, we finally also obtained some initial proof-of-principle for time- and concentration-dependent target-specific gene silencing, suggesting that these systems hold significant potential for further in vitro and in vivo evaluation.
Kostka, Libor,Koňák, ?estmír,?ubr, Vladimír,?pírková, Milena,Addadi, Yoseph,Neeman, Michal,Lammers, Twan,Ulbrich, Karel
experimental part
p. 169 - 179
(2012/02/04)

Coiled coil peptides as universal linkers for the attachment of recombinant proteins to polymer therapeutics
We have designed, synthesized, and characterized peptides containing four repeats of the sequences VAALEKE (peptide E) or VAALKEK (peptide K). While the peptides alone adopt in aqueous solutions a random coil conformation, their equimolar mixture forms heterodimeric coiled coils as confirmed by CD spectroscopy. 5-Azidopentanoic acid was connected to the N-terminus of peptide E via a short poly(ethylene glycol) spacer. The terminal azide group enabled conjugation of the peptide with a synthetic drug carrier based on the N-(2-hydroxypropyl)methacrylamide copolymer containing propargyl groups using "click" chemistry. When incorporated into the polymer drug carrier, peptide E formed a stable noncovalent complex with peptide K belonging to a recombinant single-chain fragment (scFv) of the M75 antibody. The complex thereby mediates a noncovalent linkage between the polymer drug carrier and the protein. The recombinant scFv antibody fragment was selected as a targeting ligand against carbonic anhydrase IX - a marker overexpressed by tumor cells of various human carcinomas. The antigen binding affinity of the polymer-scFv complex was confirmed by ELISA. This approach offers a well-defined, specific, and nondestructive universal method for the preparation of protein (antibody)-targeted polymer drug and gene carriers designed for cell-specific delivery.
Pechar, Michal,Pola, Robert,Laga, Richard,Ulbrich, Karel,Bednarova, Lucie,Malon, Petr,Sieglova, Irena,Kral, Vlastimil,Fabry, Milan,Vanek, Ondrej
body text
p. 3645 - 3655
(2012/06/30)

Multivalent benzoboroxole functionalized polymers as gp120 glycan targeted microbicide entry inhibitors
Microbicides are women-controlled prophylactics for sexually transmitted infections. The most important class of microbicides target HIV-1 and contain antiviral agents formulated for topical vaginal delivery. Identification of new viral entry inhibitors that target the HIV-1 envelope is important because they can inactivate HIV-1 in the vaginal lumen before virions can come in contact with CD4+ cells in the vaginal mucosa. Carbohydrate binding agents (CBAs) demonstrate the ability to act as entry inhibitors due to their ability to bind to glycans and prevent gp120 binding to CD4+ cells. However, as proteins they present significant challenges in regard to economical production and formulation for resource-poor environments. We have synthesized water-soluble polymer CBAs that contain multiple benzoboroxole moieties. A benzoboroxole-functionalized monomer was synthesized and incorporated into linear oligomers with 2-hydroxypropylmethacrylamide (HPMAm) at different feed ratios using free radical polymerization. The benzoboroxole small molecule analogue demonstrated weak affinity for HIV-1BaL gp120 by SPR; however, the 25 mol % functionalized benzoboroxole oligomer demonstrated a 10-fold decrease in the KD for gp120, suggesting an increased avidity for the multivalent polymer construct. High molecular weight polymers functionalized with 25, 50, and 75 mol % benzoboroxole were synthesized and tested for their ability to neutralize HIV-1 entry for two HIV-1 clades and both R5 and X4 coreceptor tropism. All three polymers demonstrated activity against all viral strains tested with EC50s that decrease from 15000 nM (1500 μg mL -1) for the 25 mol % functionalized polymers to 11 nM (1 μg mL-1) for the 75 mol % benzoboroxole-functionalized polymers. These polymers exhibited minimal cytotoxicity after 24 h exposure to a human vaginal cell line.
Jay, Julie I.,Lai, Bonnie E.,Myszka, David G.,Mahalingam, Alamelu,Langheinrich, Kris,Katz, David F.,Kiser, Patrick F.
experimental part
p. 116 - 129
(2011/11/05)

Multi-component polymeric system for tumour cell-specific gene delivery using a universal bungarotoxin linker
Purpose: A new universal tool for specific, non-covalent and non-destructive attachment of a recombinant antibody fragment to a polymer-modified adenovirus has been utilised to regulate the tropism of adenoviral gene delivery vector. Methods: We have prepared a multivalent reactive N-(2-hydroxypropyl)methacrylamide-based copolymer (PHPMA) bearing an α-bungarotoxin-binding peptide (BTXbp). The copolymer was used for covalent surface modification of adenoviral vectors (Ad). The α-bungarotoxin protein (BTX) has a nanomolar binding affinity for BTXbp, allowing non-covalent linkage of BTX fusion proteins. A single chain variable fragment of anti-PSMA antibody bearing BTX (scFv-BTX) binding to the prostate-specific membrane antigen (PSMA) was conjugated with the copolymer-coated adenovirus to enable specific infection of prostate cancer cells via PSMA receptors. Results: As shown by ELISA, the copolymer-coated virus exhibited much reduced binding to anti-Ad antibodies. Infection of PC-3 and LNCaP prostate cancer cells was ～100-fold less efficient with copolymer-coated Ad than with un-modified Ad. Conjugation of scFv-BTX with Ad-PHPMA-BTXbp led to 5-10-fold restoration of infection in PSMA-positive LNCaP cells. In PSMA-negative PC-3 cells, the conjugation of scFv-BTX with Ad-PHPMA-BTXbp gave no enhancement of infection. Conclusions: We have shown that the presented Ad-PHPMA-BTXbp/scFv-BTX system can be used as a universal tool for a receptor-specific virotherapy.
Willemsen, Ralph A.,Pechar, Michal,Carlisle, Robert C.,Schooten, Erik,Pola, Robert,Thompson, Amber J.,Seymour, Leonard W.,Ulbrich, Karel
experimental part
p. 2274 - 2282
(2011/08/08)

A fluorescent polymeric heparin sensor
Linear copolymers have been developed which carry binding sites tailored for sulfated sugars. All binding monomers are based on the methacrylamide skeleton and ensure statistical radical copolymerization. They are decorated with o-aminomethylphenylboronates for covalent ester formation and/ or alkylammonium ions for noncovalent Coulomb attraction. Alcohol sidechains maintain a high water solubility; a dansyl monomer was constructed as a fluorescence label. Statistical copoly merization of comonomer mixtures with optimized ratios was started by AIBN (AIBN = 2,2′-azoisobutyronitrile) and furnished water-soluble comonomers with an exceptionally high affinity for glucosaminoglucans. Heparin can be quantitatively detected with an unprecedented 30 nM sensitivity, and a neutral polymer without any ammonium cation is still able to bind the target with almost micromolar affinity. From this unexpected result, we propose a new binding scheme between the boronate and a sulfated ethylene glycol or aminoethanol unit. Although the mechanism of heparin binding involves covalent boronate ester formation, it can be completely reversed by protamine addition, similar to heparin's complex formation with antithrombin III.
Sun, Wei,Bandmann, Heinz,Schrader, Thomas
p. 7701 - 7707
(2008/03/14)

POLYMERIC COMPOSITIONS AND METHODS OF MAKING AND USING THEREOF
Described herein are polymeric compositions that comprise at least one polymer residue and at least one crosslinking moiety, wherein the polymer residue is crosslinked by the crosslinking moiety and wherein the crosslinking moiety is formed from a reaction between a boronic acid moiety and a hydroxamic acid moiety. Also, described are methods of making and using such polymeric compositions.
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Page/Page column 60-61

(2008/06/13)

Hydrogels of water soluble polymers crosslinked by protein domains
A stimuli-responsive, hybrid hydrogel wherein the bulk of the polymer is made up of relatively inexpensive water soluble polymer strands crosslinked by protein domains. The responsiveness of the gel is controlled or modulated by the protein component. The physical and biological properties of the hydrogel are determined by specifically designed or engineered protein domains. The crosslinking of the protein domains to the water soluble polymers is by means of non-covalent bonding such as chelation or coordination bonding, biotin-avidin bonding, protein—protein interaction and protein-ligand interaction, or by means of covalent bonding. Methods of making and using the polymer-protein hydrogels are disclosed in this application.
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Page/Page column 10; 11

(2010/11/25)

MICELLAR CARRIERS FOR DRUGS WITH ANTI-CANCER ACTIVITY
A micellar system destined for controlled release of medical drug is formed by a micellar structure, constituted by a hydrophilic or amphiphilic polymer, to which the drug is bound by a covalent linkage, the molecules of which are arranged on the hydrophilic surface of the micelle, while the nucleus of the micelle is constituted by hydrophobic components of the system, which are linked with the polymer on the surface by a chemical bond.
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Page/Page column 6

(2010/11/28)

Arginine- and lysine-specific polymers for protein recognition and immobilization
Free radical polymerization of methacrylamide-based bisphosphonates turns weak arginine binders into powerful polymeric protein receptors. Dansyl-labeled homo- and copolymers with excellent water solubility are accessible through a simple copolymerization protocol. Modeling studies point to a striking structural difference between the stiff rodlike densely packed homopolymer 1 and the flexible copolymer 2 with spatially separated bisphosphonate units. Fluorescence titrations in buffered aqueous solution (pH = 7.0) confirm the superior affinity of the homopolymer toward oligoarginine peptides reaching nanomolar KD values for the Tat peptide. Basic proteins are bound almost equally well by 1 and 2 with micromolar affinities, with the latter producing much more soluble complexes. The Arg selectivity of the monomer is transferred to the polymer, which binds Arg-rich proteins 1 order of magnitude tighter than lysine-rich pendants of comparable pl, size, and (Arg/Lys vs Glu/Asp) ratio. Noncovalent deposition of both polymers on glass substrates via polyethyleneimine layers results in new materials suitable for peptide and protein immobilization. RlfS measurements allow calculation of association constants Ka as well as dissociation kinetics kD. They generally confirm the trends already found in free solution. Close inspection of electrostatic potential surfaces suggest that basic domains favor protein binding on the flat surface. The high specificity of the bisphosphonate polymers toward basic proteins is demonstrated by comparison with polyvinyl sulfate, which has almost no effect in RlfS experiments. Thus, copolymerization of few different comonomer units without cross-linking enables surface recognition of basic proteins in free solution as well as their effective immobilization on surfaces.
Renner, Christian,Piehler, Jacob,Schrader, Thomas
p. 620 - 628
(2007/10/03)

Polymer Side-Chain Degradation as a Tool to Control the Destabilization of Polyplexes
Purpose. We purposed to design a cationic polymer that binds to pDNA to form polyplexes and that subsequently degrades within a few days at physiological pH and temperature, releasing the DNA in the cytosol of a cell. Methods. We synthesized a new monomer carbonic acid 2-dimethylamino-ethyl ester 1-methyl-2-(2-methacryloylamino)-ethyl ester (abbreviated HPMA-DMAE) and the corresponding polymer. Hydrolysis of the carbonate ester of both the monomer and the polymer was investigated at 37°C. The DNA condensing properties of the pHPMA-DMAE was studied using dynamic light scattering (DLS) and zeta potential measurements. Degradation of the polyplexes at 37°C and pH 7.4 was monitored with DLS and gel electrophoresis. In vitro transfections were performed in COS-7 cell line. Results. pHPMA-DMAE is able to condense DNA into small particles (110 nm) with a positive zeta potential. The half-life of the polymer and monomer at 37°C and pH 7.4 was around 10 h whereas at pH 5, the half-life was 380 h. In line with this, due to hydrolysis of the side groups, pHPMA-DMAE-based polyplexes dramatically increased in size at 37°C and pH 7.4 whereas at pH 5.0, only a very small increase was observed. Interestingly, intact DNA was released from the polyplexes after 48 h at pH 7.4 whereas all DNA remained bound to the polymer at pH 5.0. Polyplexes were able to transfect cells with minimal cytotoxicity if the endosomal membrane-disrupting peptide INF-7 was added to the polyplex formulation. Conclusions. Degradation of the cationic side-chains of a polymer is a new tool for time-controlled release of DNA from polyplexes, preferably within the cytosol and/or nucleus.
Funhoff, Arjen M.,Van Nostrum, Cornelus F.,Janssen, Adrienne P. C. A.,Fens, Marcel H. A. M.,Crommelin, Daan J. A.,Hennink, Wim E.
p. 170 - 176
(2007/10/03)

Polymeric conjugates of antitumor agents
Water soluble polymeric conjugates of antitumor agents of formula (A) P-[W2]p-S0-[W1]r-[D] wherein: P is a water soluble polymer; [W1] is a residue of formula —HN-Z1-CO— in which Z1 represents a linear or branched C2-C12 alkylene chain or the residue of formula —C6HC—CH2—O—; [W2] is a residue of formula —HN-Z2-CO— in which Z2 represents a C2-C12 linear or branched alkylene chain; p and r are 0 or 1; S0 is a peptide that selectively is cleaved at the tumor site mainly by the action of the matrix metalloproteinases gelatinase; [D] is the residue of an antitumor agent. The conjugates possess enhanced antitumor activity and decreased toxicity with respect to the free drug. A process for their preparation, useful intermediates and pharmaceutical compositions containing them are also described.
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(2008/06/13)

Degradation mechanism and kinetics of thermosensitive polyacrylamides containing lactic acid side chains
Diblock copolymers of poly(N-isopropylacrylamide-co-N-(2-hydroxypropyl)methacrylamide lactate) (poly(NIPAAm-co-HPMAm-lactate)) as a thermosensitive block and poly(ethylene glycol) (PEG) as a hydrophilic block form polymeric micelles above the cloud point (CP) of the temperature-sensitive block. Destabilization of these micelles occurs upon hydrolysis of the lactate side chains. Here we report on the degradation kinetics of the HPMAm-mono(di)lactate monomers and their copolymers with NIPAAm. The degradation of the monomers and polymers in their soluble state (thus below their CP) followed normal ester hydrolysis behavior: the degradation rate increased with temperature, pH (from pH 7.5 to 11), and dielectric constant of the medium. Above the CP, where the polymers are in a precipitated state, a significant retardation of the polymer degradation occurred due to a decrease of dielectric constant of the local environment of the precipitated polymer. This study shows that it is possible to predict the rate of formation of HPMAm in NIPAAm-co-HPMAm-lactate copolymers with results in an increase of the overall hydrophilicity of the polymers and destabilization of polymeric micelles based on poly(NIPAAm-co-HPMAm-lactate).
Neradovic,Van Steenbergen,Vansteelant,Meijer,Van Nostrum,Hennink
p. 7491 - 7498
(2007/10/03)

DRUG DELIVERY SYSTEM FOR THE SIMULTANEOUS DELIVERY OF DRUGS ACTIVATABLE BY ENZYMES AND LIGHT
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(2008/06/13)

Synthesis of copolymers of N-(2-hydroxypropyl)methacrylamide with acrylic acid and gentamicin salts of these copolymers
Water-soluble copolymers of N-(2-hydroxypropyl)methacrylamide with acrylic acid were prepared by radical copolymerization in ethanol or isopropanol at 65°C in the presence of azobis(isobutyronitrile). The composition and molecular weight of the copolymers were determined, and ways to control these parameters were revealed. Reaction of N-(2-hydroxypropyl)methacrylamide-acrylic acid copolymcrs with an antibiotic gentamicin in aqueous solutions gave polymeric salts containing various amounts of this antibiotic. The ionic binding of gentamicin to the copolymcrs was confirmed by equilibrium dialysis.
Solovskii,Denisov,Ryadinskaya,Petukhova,Okulova
p. 1443 - 1449
(2007/10/03)

Biologically active compounds
The present invention provides polymer-bound anthracyclines of formula A which consists essentially of three units represented by formulae 1, 2 and 3: STR1 wherein: Gly represents glycine; n is 0 or 1; x is from 70 to 98 mol %, y is from 1 to 29 mol %, z is from 1 to 29 mol %, R1 is a C1 -C6 alkyl group substituted by one or more hydroxy groups; Y is an amino acid residue or a peptide spacer; [NH--D] is the residue of an anthracycline aminoglycoside [NH2 --D]; and Z is a hydroxy group or a residue of formula --NHR1 wherein R1 is as defined above. Methods for their preparation and pharmaceutical compositions containing them are also provided.
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(2008/06/13)

ENZYMATICALLY CATALYZED GENERATION OF ELECTRONICALLY EXCITED STATES IN A SYNTHETIC COPOLYMER WITH A SCHIFF BASE IN PENDANT GROUPS
The copolymer of N-(2-hydroxypropyl)methacrylamide and N-hexane-1,6-diamime (17.6 mole percent) was prepared as a model compound for investigation of a mechanism of enzymatically catalyzed generation of electronically excited states in proteins.The amino end groups of the copolymer side chains were transformed into a Schiff base by reaction with glycolaldehyde.The modified copolymer was characterized by its ultraviolet, visible and fluorescence spectra.The enzymatically catalyzed oxidation of the modified copolymer was carried out in a phosphate buffer at pH 7 using horseradish peroxidase as the enzyme.The generation of electronically excited states was demonstrated by chemiluminiscence measurement and by spectroscopic procedure based on transfer of the excitation energy to bilirubin.
Zoulik, Robert,Pavlicek, Zdenek,Vohlidal, Jiri,Subr, Vladimir
p. 95 - 103
(2007/10/02)

Hydrolytically degradable hydrophilic gels and the method for preparation thereof using N,O-dimethacryloylhydroxylamine as a cross-linking agent
The solution pertains to hydrolytically degradable hydrophilic gels consisting of the individual chains of hydrophilic polymer interconnected with crosslinks containing the structure unit STR1 The method for preparation of the hydrolytically degradable gels consists in subjecting hydrophilic monomers or their mixture to the radical polymerization or copolymerization, or to copolymerization with hydrophobic monomers, in the presence of a new compound--N,O-dimethacryloylhydroxylamine--as a crosslinking agent, and, if desired, in the presence of a solvent, whereas the amount of hydrophilic monomers is 50 to 99.8 molar percent related to all monomers present.
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(2008/06/13)

Hydrolytically degradable hydrophilic gels and the method for preparation thereof
The solution pertains to hydrolytically degradable hydrophilic gels consisting of the individual chains of hydrophilic polymer interconnected with crosslinks containing the structure unit The method for preparation of the hydrolytically degradable gels consists in subjecting hydrophilic monomers or their mixture to the radical polymerization or copolymerization, or to copolymerization with hydrophobic monomers, in the presence of a new compound - N,O-dimethacryloylhydroxylamine - as a crosslinking agent, and, if desired, in the presence of a solvent, whereas the amount of hydrophilic monomers is 50 to 99.8 molar percent related to all monomers present.
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(2008/06/13)