3D-printing flexible PLGA scaffold modified with bioorthogonal IGF-1 for skin regeneration

3D-printing implants have attracted increasing attention for enhancing the regeneration of various wound types. The rigidity of traditional 3D printing materials limits their applicability in skin wound repair. In addition, improving the bioactivity of polymeric materials remains an urgent challenge to be addressed. Insulin-like growth factor-1 (IGF-1) is widely recognized for its efficacy in skin wound repair. However, the potency of IGF-1 in wound regeneration is limited by its unstable binding to the implants.

In this study, A phase inversion-based deposition modeling 3D printing technique was employed to construct flexible poly(lactic-co-glycolic acid) (PLGA) scaffold. Additionally, a novel 3D-printing flexible skin implantation functionalized with bioorthogonal IGF-1 (DA-IGF-1) was fabricated. The adhesion, proliferation and relative mRNA expression of cells on PLGA scaffold were assessed. Meanwhile, a full-thickness skin defect regeneration model was established on the rat back to evaluate the wound repair efficacy of the implanted scaffolds.

The DA-IGF-1 exhibited outstanding binding ability on the scaffold. The resulting PLGA flexible scaffold modified with DA-IGF-1 showed significantly enhanced hydrophilicity and biocompatibility compared with the control group materials (p < 0.05). The expression of wound regeneration related genes was also upregulated significantly in the DA-IGF-1 group (p < 0.05). In vivo study indicated that bioactive implants effectively promoted healing and neovascularization of full-thickness skin defects in rats.

These results demonstrated that the 3D-printing flexible PLGA scaffold modified with bioorthogonal IGF-1 holds great potential for application as a novel therapeutic strategy for wound regeneration.