220215-00-9Relevant articles and documents
Dendrimers functionalized with a single fluorescent dansyl group attached 'off center': Synthesis and photophysical studies
Cardona, Claudia M.,Alvarez, Julio,Kaifer, Angel E.,McCarley, Tracy Donovan,Pandey, Siddharth,Baker, Gary A.,Bonzagni, Neil J.,Bright, Frank V.
, p. 6139 - 6144 (2000)
A series of three new fluorescent dendrimers containing a single, focally located dansyl group and 3 (1), 9 (2), and 27 (3) carboxylic acid groups in their peripheries were synthesized and characterized. The photophysical properties of these dendrimers were investigated in aqueous solution. The host-guest interactions of the dendrimers through their dansyl subunits with β-cyclodextrin and polyclonal anti-dansyl antibodies were also investigated by various methods. Photophysical measurements on the dendrimers demonstrate that the dansyl residue is progressively shielded from the solvent as the dendrimer generation increases, resulting in marked changes in spectral features, fluorescence quantum yields, excited-state fluorescence lifetimes, radiative and nonradiative decay rates, and rotational reorientation times. The excited-state intensity decay kinetics for 1-3 are well described by a single exponential. Contrary to the popularly held belief that lower generation dendrimers are 'floppy' species in solution, the molecular motions of 1-3 are described by a single rotational reorientation time. Access to the dansyl moiety is impeded with increasing dendrimer size as the dendrimer mass affords a significant degree of protection from binding by nonselective (β-cyclodextrin (βCD)) and selective (anti-dansyl antibody) hosts for the dansyl residue. The equilibrium constant for β-CD binding of the dansyl residue in 1 is ~2.5-fold lower than that for binding to dansylamine (DA). Dendrimers 2 and 3 do not associate with β-CD at all. Anti-dansyl antibodies can bind to the dansyl residue in dendrimers 1-3 with remarkably large binding affinities. The equilibrium constant for the antibody complex decreases systematically from 5.0 x 107 M-1 for DA to 1.5 x 106 M-1 for 3.
Strain-promoted alkyne azide cycloaddition for the functionalization of poly(amide)-based dendrons and dendrimers
Ornelas, Catia,Broichhagen, Johannes,Weck, Marcus
, p. 3923 - 3931 (2010)
Functionalization of a poly(amido)-based dendron with ethylene glycol chains (PEG) using coppercatalyzed alkyne azide cycloaddition (CuAAC) afforded dendrons with significant levels of copper contaminations, preventing the use of such materials for biological applications. We suggest that the presence of amide, PEG, and triazole functional groups allows for copper complexation, thereby preventing the separation of the copper catalyst from the final dendron. To minimize this problem, synthetic variations on CuAAC including the addition of "click" additives for copper sequestering as well as the use of copper wire as the copper source were investigated. None of these strategies, however, resulted in copper-free products. In contrast, we developed a copper-free strain-promoted alkyne azide cycloaddition (SPAAC) strategy that functionalized poly(amide)-based dendrons and dendrimers with PEG chains quantitatively under mild reaction conditions without any metal contamination. The SPAAC products were characterized by 1H and 13C NMR, 2D HSQC and COSY NMR, mass spectrometry, and elemental analysis. This is the first report on the use of SPAAC for dendrimer functionalization, and the results obtained here show that SPAAC is an important tool to the dendrimer and more general biomaterials community for the functionalization of macromolecular structures due to the mild and metal-free reaction conditions, no side products, tolerance toward functional groups, and high yields.
Construction of a well-defined multifunctional dendrimer for theranostics
Ornelas, Catia,Pennell, Ryan,Liebes, Leonard F.,Weck, Marcus
, p. 976 - 979 (2011)
A dendrimer-based building block for theranostics was designed. The multifunctional dendrimer is polyamide-based and contains nine azide termini, nine amine termini, and fifty-four terminal acid groups. Orthogonal functionalization of the multifunctional
Multifunctional degradable nanoparticles with control over size and functionalities
-
Page/Page column 132-133, (2018/02/03)
In one aspect, the invention relates to polymers, crosslinked polymers, functionalized polymers, nanoparticles, and functionalized nanoparticles and methods of making and using same. In one aspect, the invention relates to degradable polymers and degradable nanoparticles. In one aspect, the invention relates to methods of preparing degradable nanoparticles and, more specifically, methods of controlling particle size during the preparation of degradable nanoparticles. In one aspect, the degradable nanoparticles are useful for complexing, delivering, and releasing payloads, including pharmaceutically active payloads. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present invention.
Combining aminocyanine dyes with polyamide dendrons: A promising strategy for imaging in the near-infrared region
Ornelas, Catia,Lodescar, Rachelle,Durandin, Alexander,Canary, James W.,Pennell, Ryan,Liebes, Leonard F.,Weck, Marcus
supporting information; scheme or table, p. 3619 - 3629 (2011/05/05)
Cyanine dyes are known for their fluorescence in the near-IR (NIR) region, which is desirable for biological applications. We report the synthesis of a series of aminocyanine dyes containing terminal functional groups such as acid, azide, and cyclooctyne groups for further functionalization through, for example, click chemistry. These aminocyanine dyes can be attached to polyfunctional dendrons by copper-catalyzed azide alkyne cycloaddition (CuAAC), strain-promoted azide alkyne cycloaddition (SPAAC), peptide coupling, or direct SNR1 reactions. The resulting dendron-dye conjugates were obtained in high yields and displayed high chemical stability and photostability. The optical properties of the new compounds were studied by UV/Vis and fluorescence spectroscopy. All compounds show large Stokes shifts and strong fluorescence in the NIR region with high quantum yields, which are optimal properties for in vivo optical imaging.
