Preparation and characterization of a novel polysialic acid-hyaluronan graft copolymer potential as dermal filler.

Polysialic acid (PSA) and hyaluronan (HA) are non-immunogenic and biodegradable natural polysaccharides, but HA belongs to glycosaminoglycans and can be immediately degraded by human enzymes. In this study, we synthesized a novel PSA-HA draft copolymer to improve HA stability in vivo. This draft copolymer was characterized by SEM, element analysis and Zeta potential. Cytotoxicity assays, as well as pyrogen and hemolysis tests, were also conducted to test its biological functions further. Results showed that PSA-HA draft copolymer satisfies the medical requirement for biomaterials. In vivo degradation test proved that this copolymer can reduce the irritation rate and prolong the duration of cross-linked HA in skin. These results indicated that PSA-HA draft copolymer can be potentially used as an alternative for free HA in dermal filler (dual-phase cross-linked HA system).