Preparation and characterization of Panax notoginseng saponins loaded hyaluronic acid/carboxymethyl chitosan hydrogel for type o diabetic wound healing

Hyaluronic acid (HA)/carboxymethyl chitosan (CMCS) hydrogel was synthesized by using 1-(3-dimethylaminopropyl) − 3-ethylcarbondiimide (EDC) and N-hydroxysuccinimide (NHS) as chemical cross-linking agents. The panax notoginseng saponins (PNS) loaded HA/CMCS hydrogel was prepared by immersion method. The swelling, sustained-releasing, biocompatible, anti-inflammatory and anti-oxidant properties of the hydrogel were investigated, and healing effect of the hydrogel was verified by applying it to skin wound in typeⅡdiabetic SD rats. The results showed that HA/CMCS hydrogel had good swelling property and could absorb water up to 46 times of its own dry weight. The PNS was continuously released in the simulated body fluid for 24 h, and the release rate was 76 %. In vitro cytotoxicity, anti-oxidant and anti-inflammatory experiment of inhibiting macrophage secretion of NO showed that the addition of low concentration PNS(≤5 mg/mL) facilitated cell proliferation and improved the biocompatibility. The ABTS free radical scavenging rate of HA/CMCS-PNS can reach 99 %. In animal experiments, HA/CMCS-PNS hydrogel significantly improved the wound healing speed of SD rats, decreased the expression of TNF-α and IL-6, quickly enhanced the expression of IL-10, and attenuated the body's inflammation response. In the process of wound healing, HA/CMCS-PNS hydrogel up-regulated the expression of VEGF and bFGF in wound, promoted angiogenesis and epithelial cell regeneration, and synergistically promoted the rapid wound healing.