Innovative approach for producing injectable, biodegradable materials using chitooligosaccharides and green chemistry

摘要

Although there are a number of injectable biomaterials currently under development, they present some drawbackssuch as being based on synthetic polymers, needing toxic or aggressive synthesis procedures or using raw materialswith low availability and/or high production costs. Having this in mind, a novel injectable biomaterial usingchitooligosaccharides as starting materials was developed. This system uses a widely available and cheap polymerfrom marine biomass (chitosan), which can be turned into an injectable material by water-based and ecologicallyfriendly reactions. Chitooligosaccharides were functionalized with methacrylic groups, to allow in situ crosslinking.The degree of substitution, as determined by 1H NMR, varied between 5 and 50%. The system wascharacterized in terms of kinetics of gel formation, rheology, degradation behavior and in vitro cytotoxicity. Thegelation time could be easily tailored between 1.5 and 60 min by changing the conditions of the methacrylationreaction, and the final gel presented rheological properties typical of strong gels, that is, shear stresses in the kParange. The cross-linked gel was degradable and nontoxic, presenting indeed an interesting cytokinetic effect.Injectable materials based on chitooligosaccharides are, therefore, an innovative system combining adequatebiological performance, ease of preparation, and an ecologically friendly concept of production.