Nanocurcumin-enhanced zein nanofibers: Advancing macrophage polarization and accelerating wound healing

Introduction

Chronic wounds continue to pose a significant global challenge, incurring substantial costs and necessitating extensive research in wound healing. Our previous work involved synthesizing zein nanofibers embedded with 5 %, 10 %, and 15 % nano-curcumin (Zein/nCUR 5, 10, and 15 % NFs), and examining their physicochemical and biological properties. This study aims to explore the potential of these nanofibers in macrophage (MØ) polarization and wound healing.

Methods

We assessed the survival of RAW264.7 cells cultured on Zein/nCUR 5, 10, and 15 % NFs using the MTT assay. To evaluate MØ polarization, we measured the expression of iNOS and Arg-1 genes in MØs cultured on Zein/nCUR 10 % NFs through real-time PCR. Furthermore, we examined the nanofibers' impact on pro-inflammatory cytokine expression (IL-1β, IL-6, TNF-α) in MØs via real-time PCR. The wound healing efficacy of Zein/nCUR 10 % NFs was tested on 54 male rats with full-thickness wounds, with assessments conducted on days 3, 7, and 14. Wound closure, re-epithelialization, and collagen secretion were evaluated through photographic analysis and tissue staining. Statistical analyses were performed using GraphPad Prism 6, with significance set at p < 0.05.

Results

Zein/nCUR 10 % NFs significantly enhanced the survival of RAW264.7 cells compared to other groups. They also markedly reduced iNOS expression and increased Arg-1 expression, indicating successful polarization of M1 to M2 MØs. Additionally, these nanofibers decreased the expression of IL-1β, IL-6, and TNF-α, and significantly improved wound closure, re-epithelialization, and collagen deposition compared to control and Zein groups.

Conclusions

This study demonstrates that Zein/nCUR 10 % NFs effectively polarize MØs from M1 to M2, significantly enhancing wound healing, thus offering a promising therapeutic approach for improved wound care.