Synthesis and Characterization of a New Polysaccharide-graft-polymethacrylate Copolymer for Three-Dimensional Hybrid Hydrogels

Abstract

Hybrid materials constituted by hydrophobic and hydrophilic biocompatible macromolecules are useful for biomedical applications. In this context, a well-known acrylic monomer (methyl methacrylate) was polymerized and grafted onto the polysaccharide dextran by the use of ceric ammonium nitrate as a redox initiator in aqueous nitric acid medium. The effects of concentrations of dextran, acrylic monomer, and ceric ions on the copolymerization yields were investigated in detail. The obtained polymers were studied by solubility measurements, Fourier transform infrared spectrometry, (13)C nuclear magnetic resonance spectroscopy, and viscosimetric analysis. Interestingly, we found conditions to form transparent and homogeneous thin films or 3D structures with hybrid properties. Indeed, the copolymer, but not dextran or PMMA, could be dissolved in water/THF (20/80 v/v). The thermomechanical properties of the resulting copolymer analyzed by differential scanning calorimetry and dynamic mechanical analysis showed the occurrence of a single glass-transition temperature and a marked difference with the two homopolymers. The cytocompatibility of the copolymer with human endothelial cells was evidenced by the normal cell adhesion, proliferation, and morphology after 5 days in culture on these gels. In conclusion, this type of copolymer with hybrid properties of two biocompatible macromolecules could be of great interest as a 3D scaffold or for coating in biomedical applications.

Functionalized Graphene Oxide Nanoparticles for Cancer Cell-Specific Delivery of Antitumor Drug

“…The fabricating approach for the biocompatible and reduction-responsive CPMAA-GO-PEG nanocarriers is presented in Scheme 1, via the classic amidation of the carboxyl groups of the GON nanoparticles with the amine end-groups of the functional poly(ethylene glycol) (PEG), and the radical polymerization of MAA initiated with the redox system of cerium ammonium nitrate (CAN)/the active hydrogen atoms of the GON-PEG nanoparticles (Table 1), [26][27][28] finally the crosslinking of the PMAA brushes with cystamine as a crosslinker (Table 2), to endow the PMAA-GON-PEG having reduction responsiveness in the presence of high level cysteine or glutathione (GSH) in the cytoplasm and endolysosomes. 29 After the PEGylation with NH 2 -PEG, the characteristic absorbance at 1720 cm -1 of carbonyl band in carboxylic acid disappeared, while the new absorbance at 1650 cm -1 of carbonyl band in amide group and characteristic peak at 1110 cm -1 of oxygen stretching vibration of the C-O-C group appeared ( Figure 1).…”

Effects of Transplanted Heparin-Poloxamer Hydrogel Combining Dental Pulp Stem Cells and bFGF on Spinal Cord Injury Repair

“…Moreover, HP has a high affinity to growth factors (GFs) such as nerve growth factor (NGF) and acidic fibroblast growth factor (aFGF) and is also able to protect GFs from degradation of protease [ 32 , 33 ]. In addition, HP hydrogel shows a 3D porous structure and has great cytocompatibility [ 30 , 34 ]. Thus, in this study, we used HP as the engineered tissue scaffold and transplanted HP hydrogel containing bFGF and DPSCs into the injured site of the spinal cord in order to investigate the effects of DPSCs combined with bFGF on neural regeneration and functional recovery after SCI.…”

Temperature-responsive self-assembly of charged and uncharged hydroxyethylcellulose-graft-poly(N-isopropylacrylamide) copolymer in aqueous solution

“…Redox reaction systems of Ce (IV) with reducing agents (e.g., alcohols, aldehydes, ketones, acids, amines, thiols, etc.) in aqueous solution are well-known initiators for vinyl polymerization of homopolymers and block copolymers; graft copolymers can be easily prepared by this system [29–32]. …”