Injectable gelatin microspheres loaded with platelet rich plasma improve wound healing by regulating early inflammation

Shaolong Zhou^1#, Li Li^1#, Chen Chen¹, Yi Chen¹, Linhua Zhou¹, Fiona H. Zhou^2,3, Jianghui Dong^2✉, Liping Wang^2✉

1. Aesthetic Medical School, Yichun University, Yichun, 336000, Jiangxi, China.
2. UniSA Clinical & Health Sciences, University of South Australia, Adelaide, SA 5001, Australia.
3. School of Medicine, University of Adelaide, Adelaide, South Australia, 5000, Australia.
#These authors contributed equally to this work.

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Citation:
Zhou S, Li L, Chen C, Chen Y, Zhou L, Zhou FH, Dong J, Wang L. Injectable gelatin microspheres loaded with platelet rich plasma improve wound healing by regulating early inflammation. Int J Med Sci 2021; 18(9):1910-1920. doi:10.7150/ijms.51060. Available from https://www.medsci.org/v18p1910.htm

Abstract

We investigated the potential of gelatin microspheres (GMs) loaded with platelet-rich plasma (PRP) to enhance their wound healing effect. Platelets from the PRP were immobilized onto GMs to form biomimetic bioreactor GM+PRP. The therapeutic effect of this agent was further investigated in vivo on a wound-healing model in rats. Wounds were locally injected with phosphate buffered saline (PBS), GM, PRP, and GM+PRP. Wound healing rate, vessel density, and inflammation level were measured histologically, by RT-PCR, and by Western blotting at days 3, 7, 14, and 21. Platelets on GM caused a continuous high release in both interleukin-10 and metalloproteinase-3 compared with PRP alone. Both GM+PRP and PRP successfully accelerated the wound healing process, while GM alone did not improve the wound healing process compared with the untreated control. Wounds treated with GM+PRP resulted in shorter healing period and improved dermal structure. GM+PRP improved angiogenesis in the wound by increasing expression of angiogenic factors. GM+PRP prolonged and enhanced the cytokine release profile compared with PRP. By promoting the inflammatory and angiogenic responses, GM+PRP has the potential to improve wound healing. Our findings demonstrate that GMs are an injectable carrier that enhanced the therapeutic effects of PRP.

Keywords: platelet-rich plasma, gelatin microspheres, early inflammation, wound healing, tissue regeneration