Investigation of construction and characterization of carboxymethyl chitosan - sodium alginate nanoparticles to stabilize Pickering emulsion hydrogels for curcumin encapsulation and accelerating wound healing.

Limitations in compatibility and effectiveness in delivering bioactive compounds often make it prohibitively difficult to apply Pickering emulsions in wound dressing. In this research, we prepared Pickering emulsion composite hydrogels based on carboxymethyl chitosan - sodium alginate (CMCS-SA) nanoparticles (NPs) stabilized Pickering emulsions, poloxamer 407 (PLX), and curcumin (CUR). CMCS-SA NPs were prepared and used to stabilize Pickering emulsion. The stability of Pickering emulsion improved with the increase of the concentration of NPs, and was highly sensitive to ionic strength change. This Pickering emulsion remained stable at various temperatures. After curcumin were introduced into the emulsion, 0.6% CMCS-SA NPs Pickering emulsion showed controlled release of curcumin in vitro. The CMCS-SA-PLX-CUR hydrogels also exhibited smooth surface and dense structure. This composite hydrogels has antibacterial properties against Escherichia coli and Staphylococcus aureus. Moreover, the CMCS-SA-PLX-CUR hydrogels improved wound healing and increased expression of Ki67 and CD31. RT-qPCR results indicated that the mRNA levels of α-SMA and TGF-β1 in the CMCS-SA-PLX-CUR group were downregulated, while the mRNA levels of TGF-β3 increased. The present study suggests that the potentials of CMCS-SA-PLX-CUR hydrogels are promising in protecting bioactive components and wound care management.