36837-97-5Relevant articles and documents
Synthesis and chemical degradation of branched vinyl polymers prepared via ATRP: Use of a cleavable disulfide-based branching agent
Li, Yuting,Armes, Steven P.
, p. 8155 - 8162 (2005)
Highly branched poly(2-hydroxypropyl methacrylate) has been prepared by atom transfer radical polymerization (ATRP) in methanol at 20°C using a disulfide-based dimethacrylate (DSDMA) branching agent. The mean degree of polymerization of the primary chains was fixed at 50; since ATRP has reasonably good living character, the molecular weight distribution of these primary chains is relatively narrow, which allows significantly better control than conventional radical polymerization. Varying the proportion of the DSDMA produced a series of soluble branched polymers, provided that there was on average less than one branching agent per primary chain. However, higher levels of DSDMA lead to macrogelation, as expected. The soluble branched polymers were characterized using triple detector gel permeation chromatography (GPC). The most highly branched copolymers had weight-average molecular weights of up to 540 000, with polydispersities of around 8.0 and Mark-Houwink a parameters as low as 0.21 being obtained. 1H NMR spectroscopy confirmed that very high monomer conversions were obtained (>99%), and the final branched copolymers contained little or no unreacted pendent vinyl groups. The disulfide bond in the DSDMA branching agent was readily cleaved using either dithiothreitol or benzoyl peroxide. GPC studies confirmed the progressive decrease in molecular weight and polydispersity during the chemical degradation of one of the branched copolymers with reaction time. Eventually, the final polydispersity of this degraded branched copolymer was comparable to that of linear poly(2-hydroxypropyl methacrylate) prepared in the absence of any disulfide-based dimethacrylate branching agent. Thus, all the disulfide bonds had been cleaved, reducing the branched copolymer to its near-monodisperse primary chains.
DNA polyplexes formed using PEGylated biodegradable hyperbranched polymers
Tao, Lei,Chou, William C.,Tan, Beng H.,Davis, Thomas P.
, p. 632 - 637 (2010)
A novel PEGylated biodegradable hyperbranched PEG-b-PDMAEMA has been synthesized. The low toxicity, small molecular weight PDMAEMA chains were crosslinked using a biodegradable disulfide-based dimethacrylate (DSDMA) agent to yield higher molecular weight hyperbranched polymers. PEG chains were linked onto the polymer surface, masking the positive charge (as shown by Zeta potential measurements) and reducing the toxicity of the polymer. The hyperbranched structures were also cleaved under reducing conditions and analyzed, confirming the expected component structures. The hyperbranched polymer was mixed with DNA and efficient binding was shown to occur through electrostatic interactions. The hyperbranched structures could be reduced easily, generating lower toxicity oligomer chains. (Chemical Presented).
Cytoplasmic delivery of functional siRNA using pH-Responsive nanoscale hydrogels
Liechty, William B.,Scheuerle, Rebekah L.,Vela Ramirez, Julia E.,Peppas, Nicholas A.
, p. 249 - 257 (2019)
The progress of short interfering RNA (siRNA) technologies has unlocked the development of novel alternatives for the treatment of a myriad of diseases, including viral infections, autoimmune disorders, or cancer. Nevertheless, the clinical use of these therapies faces significant challenges, mainly overcoming the charged and large nature of these molecules to effectively enter the cell. In this work, we developed a cationic polymer nanoparticle system that is able to load siRNA due to electrostatic interactions. The pH-responsiveness and membrane-disrupting ability of these carriers make them suitable intracellular delivery vehicles. In the work presented herein we synthesized, characterized, and evaluated the properties of nanoparticles based on 2-diethylaminoethyl methacrylate and tert-butyl methacrylate copolymers. A disulfide crosslinker was incorporated in the nanogels to enable the degradation of the nanoparticles in reductive environments, showing no significant changes on their physicochemical properties. The capability of the developed nanogels to be internalized, deliver siRNA, and induce gene knockdown were demonstrated using a human epithelial colorectal adenocarcinoma cell line. Overall, these findings suggest that this platform exhibits desirable characteristics as a potential siRNA-delivery platform.
DELIVERY OF SMALL INTERFERING RNA AND MICRO RNA THROUGH MEMBRANE-DISRUPTIVE, RESPONSIVE NANOSCALLE HYDROGELS
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Paragraph 156 - 159, (2014/05/07)
Nanoscale, pH-responsive polycationic networks useful for the delivery of anionic biologic therapeutics and associated methods.
Functional, star polymeric molecular carriers, built from biodegradable microgel/nanogel cores
Syrett, Jay A.,Haddleton, David M.,Whittaker, Michael R.,Davis, Thomas P.,Boyer, Cyrille
supporting information; experimental part, p. 1449 - 1451 (2011/03/19)
Acid and disulfide biodegradable cross-linkers have been employed to generate microgel star polymers, using RAFT-polymer arms. RAFT end-groups were then exploited to attach functional compounds via both thiol-ene and thiol-pyridyl disulfide exchange reactions.
