Strength and histology of a nanofiber scaffold in rats

Silk fibroin/poly(L-lactic acid-co-ε-caprolactone) electrospun nanofibrous scaffolds exert a protective effect following myocardial infarction

Electrospinning using biocompatible polymer scaffolds, seeded with or without stem cells, is considered a promising technique for producing fibrous scaffolds with therapeutic possibilities for ischemic heart disease. However, no optimal scaffolds for treating ischemic heart disease have been identified thus far. In the present study, it was evaluated whether electrospun silk fibroin (SF)-blended poly(L-lactic acid-co-ε-caprolactone) [P(LLA-CL)] scaffolds that were seeded with cluster of differentiation 117 (c-kit)⁺ bone marrow (BM) cells may serve a protective role in cardiac remodeling following myocardial infarction (MI). Mechanical characteristics and cytocompatibility were compared between SF/P(LLA-CL) and P(LLA-CL) electrospun nanofibrous scaffolds in vitro. It was observed that MI led to a significant increase of the c-kit⁺ BM cell subpopulation in mice. Magnetic activated cell sorting was performed to harvest the c-kit⁺ cell population from the BM of mice following MI. c-kit⁺ BM cells were seeded on SF/P(LLA-CL) and P(LLA-CL) electrospun nanofibrous scaffolds. Results indicated that SF/P(LLA-CL) electrospun nanofibrous scaffolds were superior to P(LLA-CL) electrospun nanofibrous scaffolds in improving c-kit⁺ BM cell proliferation. Additionally, compared with pure SF/P(LLA-CL) electrospun nanofibrous scaffolds, SF/P(LLA-CL) scaffolds seeded with c-kit⁺ BM cells resulted in lower levels of MI markers and reduced infarct size, leading to greater global heart function improvement in vivo. The findings of the present study indicated that SF/P(LLA-CL) electrospun nanofibrous scaffolds seeded with c-kit⁺ BM cells exert a protective effect against MI and may be a promising approach for cardiac regeneration after ischemic heart disease.