Recombinant humanized type III collagen freeze-dried fibers for vaginal laxity: a narrative review of mechanisms, clinical evidence, and potential relevance to pelvic floor dysfunction
Year: 2026
Type: review
Abstract: Background Vaginal laxity (VL) is a prevalent condition affecting women's quality of life, characterized by reduced vaginal tightness, sexual function impairment, and psychological distress. While surgical vaginoplasty and energy-based devices (radiofrequency and laser) are commonly used, these approaches have important limitations, including surgical risks, variable durability, and limited evidence quality. Collagen dysregulation is increasingly recognized as a key pathophysiological feature of VL, and collagen-based biomaterials have emerged as potential regenerative interventions. However, the evidence specifically linking collagen fiber biology to VL remains scattered, and a systematic synthesis of recombinant humanized type III collagen (rhCol III) for this indication is lacking. Objective This narrative review systematically summarizes current evidence on the pathophysiological role of collagen in VL, the material properties and mechanisms of action of rhCol III freeze-dried fibers, and the available preclinical and clinical data for this intervention, with consideration of its potential relevance to the broader spectrum of pelvic floor dysfunction. Findings Recombinant humanized type III collagen freeze-dried fibers exhibit good biocompatibility and biodegradability due to their structural homology with native human collagen. Their proposed mechanism of action involves three complementary pathways—physical support and structural filling, biochemical regeneration via upregulation of endogenous collagen synthesis, and microenvironment modulation including angiogenesis and anti-inflammatory effects—although several specific molecular pathways have been characterized primarily in non-vaginal tissue models and require direct validation in vaginal tissue. Available clinical evidence from a single small two-center randomized controlled trial ( n = 84) demonstrates significant short-term improvements in VL symptoms and sexual function at 4 weeks, with a favorable short-term safety profile. However, the evidence base remains early-stage, with no large-scale multicenter trials, no long-term follow-up data, and no head-to-head comparisons with established treatments. Conclusion rhCol III freeze-dried fibers represent an emerging, biologically plausible intervention for VL that warrants further investigation. Key knowledge gaps include the need for large-scale randomized trials with long-term efficacy and safety data, standardized treatment protocols, comparative effectiveness studies, and direct mechanistic validation in vaginal tissue. The potential applicability to other pelvic floor disorders remains speculative at this stage.
Source: Frontiers in Medicine
Authors: Runzhi Shi, Liehong Wang
Institutions: Qinghai University, Qinghai Red Cross Hospital
Language: English
Subfield: Urology
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $3,801
OpenAlex ID: W7221854783