[Comparative study on the degradation rate and regulatory effects of two resorbable collagen membranes during the in vivo implantation].

Abstract

Objective: To explore the differences in the performance and tissue repair promotion effects of small intestinal submucosa membrane (SIS membrane) and Bio-Gide resorbable collagen membrane (Bio-Gide membrane) by performing the subcutaneous implantation models in mice. Methods: For in vivo studies, we stablished membrane implantation models using 6-8 week-old male C57BL/6 mice. The degradation rates were explored through HE staining analysis at different time points (1 d, 3 d, 5 d, 7 d, 14 d, 28 d, 3 mice/group/time point). The influences of the two membranes on local macrophages and neovasculum were evaluated by immunofluorescence detection of F4/80 and CD31, and the mobilization effects of the two membranes on local stem cells were evaluated by immunohistochemical detection of Ki67 and CD146. For in vitro studies, mice periodontal ligament stem cells (mPDLSCs) were co-cultured with these two membrane materials, and the cell morphologies were observed by scanning electron microscopy. In addition, the gene expressions of Ki67, Cxcl1, Ccl1, Tnfa were investigated by real-time fluorescence quantitative PCR (RT-qPCR). Results: The results of in vivo studies showed that by day 28, there was no significant difference in degradation rate between these two membrane materials [SIS degradation rate (16.84±4.00) %, Bio-Gide degradation rate (24.07±3.97) %, P=0.090], illustrating that both of them could maintain the barrier effects for more than one month. In addition, there was no significant difference in the infiltration number of local F4/80 positive macrophages between these two groups by the day 3 after implantation [SIS: (20.67±5.69) cell/visual field, Bio-Gide: (25.33±2.52) cell/visual field, P=0.292]. However, compared with the Bio-Gide membrane, SIS membrane significantly promoted local CD31+vascular regeneration [SIS (4.67±1.15)cell/visual field, Bio-Gide: (1.00±1.00) cell visual field, P=0.015] and CD146+stem cell recruitment [SIS: (22.33±4.16, Bio-Gide: (11.33±2.52) cell/visual field, P=0.025]. The RT-qPCR results also showed that SIS membrane promoted the gene expression of Cxcl1 (SIS vs Bio-Gide P<0.001) in mPDLSCs, but had no effect on the gene expression of Tnfa (SIS vs Bio-Gide P=0.885). Conclusions: SIS membrane showed a similar degradation rate compared with Bio-Gide membrane, and there was no significant difference in the effects of these two membranes on local inflammation or macrophages. Therefore, both of these membranes could meet the barrier effects required by guided tissue regeneration.