Lactic Acid-Loaded Hydrogels for Post-Episiotomy Wound Healing: Microenvironment Engineering and Regenerative Strategies-A Narrative Review.

Abstract

<b>Background</b>: Post-episiotomy wound healing remains largely managed through supportive care, despite growing evidence that local biochemical conditions critically influence tissue regeneration. Lactic acid is of particular interest in this context because it is both an endogenous metabolic intermediate and a physiologic component of the vaginal microenvironment, where it contributes to acidic pH maintenance, microbial homeostasis, and mucosal protection. Beyond these local effects, lactate has emerged as a signaling metabolite involved in angiogenesis, immune regulation, and extracellular matrix remodeling, making it a relevant candidate for regenerative wound care. <b>Methods</b>: This narrative translational review integrates evidence from molecular biology, biomaterials science, and clinical obstetrics to examine the therapeutic potential of lactic acid-loaded hydrogels for post-episiotomy tissue repair. Literature from PubMed, Scopus, and Web of Science was analyzed to evaluate physicochemical design parameters, lactate-mediated signaling pathways, and available clinical outcomes. <b>Results</b>: Lactic acid may function both as a microenvironmental regulator and as a metabolic signal capable of stabilizing hypoxia-inducible factor-1α signaling, enhancing vascular endothelial growth factor expression, modulating macrophage polarization, and influencing fibroblast-mediated extracellular matrix synthesis. Hydrogel matrices provide tunable platforms for controlled lactate release, pH buffering, and mucosal compatibility. Clinical studies suggest improved epithelialization, reduced infection risk, and lower pain scores following topical lactic acid formulations in episiotomy repair. In parallel, platelet-rich plasma provides autologous growth factor enrichment that may complement regenerative signaling pathways. <b>Conclusions</b>: Integrating microenvironment stabilization through lactic acid-based hydrogels with biologically active regenerative strategies represents a promising direction for post-episiotomy wound healing. Further controlled trials and standardized biomaterial characterization are required to define optimal therapeutic protocols and confirm long-term clinical benefit.