In Vivo Degradation and Local Tissue Response of Experimental Carp Collagen Membranes: Micro-MRI and Histological Analysis

Collagen membranes are widely used in tissue and bone engineering, including guided bone regeneration (GBR). For effective and uninterrupted bone healing, a GBR membrane must maintain its functionality for an initial critical period of 4 weeks. A novel carp collagen sponge has already shown promise as a wound coating and vascular graft coating, making it a candidate for GBR applications as well. To enhance the mechanical properties and longevity of GBR membranes, we modified the basic carp collagen membrane with combinations of l-lactide, ε-caprolactone, d,l-lactide, and glycolide in various molar ratios. While traditional methods rely on histological evaluation to assess the degradation pattern and therefore suitability of GBR membranes ex vivo, this study employed micro-MRI as an innovative, noninvasive approach to monitor the in vivo degradation of carp collagen membrane and its polymer-modified variants. Our findings demonstrated that micro-MRI is a reliable and effective method for visualizing collagen membrane degradation in vivo, up to scaffold disintegration. Among the variants tested, collagen GBR membrane coated with d,l-lactide and glycolide in a 50:50 M ratio emerged as the most suitable for GBR purposes. However, since this study was conducted in the subcutaneous tissue of a rat model, further research is required to determine the behavior of carp collagen GBR membrane variants on bony surfaces.