# Sodium propionate decreases implant-induced foreign body response in mice

## TL;DR

Sodium propionate reduces inflammation and tissue scarring around implants in mice, suggesting potential for improving implant outcomes.

## Contribution

This study is the first to show that sodium propionate can reduce the foreign body response to implants in mice.

## Key findings

- Sodium propionate decreased inflammatory cell infiltration by up to 54% in treated mice.
- Treatment reduced collagen capsule thickness by 34% and foreign body giant cells by 58%.
- Angiogenesis and fibrogenesis markers like VEGF and TGF-β1 were significantly downregulated.

## Abstract

The short-chain fatty acid (SCFA) propionate, beyond its actions on the intestine, has been able to lower inflammation and modulate angiogenesis and fibrogenesis in pathological conditions in experimental animal models. Its effects on foreign body reaction (FBR), an abnormal healing process induced by implantation of medical devices, have not been investigated. We have evaluated the effects of sodium propionate (SP) on inflammation, neovascularization and remodeling on a murine model of implant-induced FBR. Polyether-polyurethane sponge discs implanted subcutaneously in C57BL/6 mice provided the scaffold for the formation of the fibrovascular tissue. Fifteen-day old implants of the treated group (SP, 100 mg/kg for 14 days) presented a decrease in the inflammatory response as evaluated by cellular influx (flow cytometry; Neutrophils 54%; Lymphocytes 25%, Macrophages 40%). Myeloperoxidase activity, TNF-α levels and mast cell number were also lower in the treated group relative to the control group. Angiogenesis was evaluated by blood vessel number and VEGF levels, which were downregulated by the treatment. Moreover, the number of foreign body giant cells HE (FBGC) and the thickness of the collagenous capsule were reduced by 58% and 34%, respectively. Collagen deposition inside the implant, TGF-β1 levels, α-SMA and TGF-β1 expression were also reduced. These effects may indicate that SP holds potential as a therapeutic agent for attenuating adverse remodeling processes associated with implantable devices, expanding its applications in biomedical contexts.