Preparation and in vitro evaluation of FGF-2 incorporated carboxymethyl chitosan nanoparticles

Fibroblast growth factor 2 (FGF-2) is a multi-functional protein involving in wound healing. However, FGF-2 is easily degradable in vivo, which limited its use for wound treatment. In this study, we investigated a drug-delivery model for FGF-2 via incorporation with biodegradable carboxylmethyl chitosan (CMCS). CMCS nanoparticles (NPs) could be synthesized by ionic gelation using CaCl₂ as a crosslinking reagent with the CMCS:CaCl₂ ratio of 1:0.8. Synthesized CMCS NPs had a diameter of 32.68±6.83nm, and were non-toxic at concentrations up to 2.5mg/ml. Incorporated CMCS:FGF-2 NPs had a diameter of 34.83±5.89nm and incorporation efficiency was 95%. CMCS:FGF-2 NPs released 36.36% and 58.47% of FGF-2 after 48h incubation in two different pH of 7.4 and 5.8, respectively. The incorporation and release processes did not have a significant effect on FGF-2 activity. Simultaneously, CMCS:FGF-2 NPs could protect FGF-2 from the degradation of trypsin in vitro. Our results laid the groundwork for the manufacturing of protein incorporated CMCS NPs for bio-applications.