Polymers containing thiol‐reactive maleimide groups on their side chains have been synthesized by utilization of a novel methacrylate monomer containing a masked maleimide. Diels‐Alder reaction between furan and maleimide was adapted for the protection of the reactive maleimide double bond prior to polymerization. AIBN initiated free radical polymerization was utilized for synthesis of copolymers containing masked maleimide groups. No unmasking of the maleimide group was evident under the polymerization conditions. The maleimide groups in the side chain of the polymers were unmasked into their reactive form by utilization of retro Diels‐Alder reaction. This cycloreversion was monitored by thermo gravimetric analysis (TGA), differential scanning calorimetry (DSC), and 1H and 13C NMR spectroscopy. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4545–4551, 2007

A Michael addition strategy involving the reaction between a maleimide double bond and amine group has been investigated for the synthesis of cryogels at subzero temperature (-8 o C).Low molecular weight PEG-based building blocks with amine end groups on one hand and disulfide containing building blocks with maleimide end groups on the other hand are combined to synthesize redox-responsive PEG cryogels. The cryogels exhibit an interconnected macroporous morphology, a high compressive modulus (> 100 kPa) and gelation yields of around 95%. While the cryogels are stable under physiological conditions, complete dissolution of the cryogels into water soluble products is obtained in the presence of a reducing agent (glutathione) in the medium. Cell seeding experiments and toxicologic analysis demonstrate their potential as scaffolds in tissue engineering.-2 -

We report the preparation and characterization of photocleavable polyurea microcapsules. First, an isocyanate end functionalized oligomer, bearing the photolabile 6-nitroveratroyloxycarbonyl group was synthesized. This oligomer, in combination with diethylenetriamine, was then utilized in the preparation of polyurea microcapsules. Polyurea microcapsules (50-300 m), loaded with a hydrophobic dye solution and consisting of a dense capsule shell were prepared via an interfacial polymerization in a stable oil-in-water emulsion system. Thanks to the intra-molecular photocleavage mechanism, the UV-triggered rupture of the photocleavable capsule shell occurred both in solution and in solid state, leading to the successful release of the encapsulated liquid core.2

Polythioethers with molar masses up to 40 kDa were prepared by UV-or thermal initiated thiolene polyaddition polymerization of an aliphatic α-olefinic ω-thiol, an AB-type monomer derived from 10-undecenoic acid, which is a bio-sourced building block obtained from castor oil. The low polarity of the starting compound and the stability of the thioether functions formed during polymerization allowed for the synthesis of polymers with similar structures to existing bulk and engineering plastics such as polyethylene. The presence of the thioether functions offered the opportunity to oxidize these polyethylene analogues by hydrogen peroxide into sulfone linkages, resulting in polysulfones, which are valuable as engineering plastic in several application fields.Thermal analysis demonstrated the increased thermal stability and melting temperature (175°C) of these polysulfones.

Design and synthesis of novel water-soluble polymers bearing reactive side chains are actively pursued due to their increasing demand in areas such as bioconjugation and drug delivery. This study reports the fabrication of poly(ethylene glycol) methacrylate based thiolreactive water-soluble polymeric supports that can serve as targeted drug delivery vehicles.Thiol-reactive maleimide units were incorporated into polymers as side chains by use of a furan-protected maleimide containing monomer. Atom transfer radical polymerization (ATRP) was employed to obtain a family of well-defined copolymers with narrow molecular weight distributions. After the polymerization, the maleimide groups were activated to their reactive form, ready for conjugation with thiol-containing molecules. Efficient functionalization of the maleimide moieties was demonstrated by conjugation of a tripeptide glutathione under mild and reagent-free aqueous conditions. Additionally, hydrophobic thiolcontaining dye (Bodipy-SH) and a cyclic peptide-based targeting group (cRGDfC) were sequentially appended onto the maleimide bearing polymers to demonstrate their efficient multi-functionalization. The conjugates were utilized for in vitro experiments over both cancerous and healthy breast cell lines. Obtained results demonstrate that the conjugates were non-toxic, and displayed efficient cellular uptake. The presence of the peptide based targeting group had a clear effect in increasing the uptake of the dye-conjugated polymers into cells when compared to the construct devoid of the peptide. Overall, the facile synthesis and highly efficient multi-functionalization of maleimide-containing thiol-reactive copolymers offer a Page 1 of 28 ACS Paragon Plus Environment Bioconjugate Chemistry 2 novel and attractive class of polyethylene glycol-based water soluble supports for drug delivery.