Histological Evaluation of Subcutaneous Tissue Reactions to a Novel Bilayer Polycaprolactone/Silk Fibroin/Strontium Carbonate Nanofibrous Membrane for Guided Bone Regeneration: A Study in Rabbits

Objectives

The selection of appropriate biomaterial for guided bone regeneration is challenging. The blending of polymers is a simple method to retain their characteristics and to compensate for the drawbacks of each component. The release of Sr⁺² (strontium) ions from the polycaprolactone/strontium carbonate (PCL/SrC) nanocomposite is the main reason of enhanced osteogenesis. The most important reasons of clinical failure after using biomaterials include infections and lack of tissue-integration. Modifications of silk fibroin (SF)–based membranes improved new bone formation in animal studies without inflammatory reaction. The aim of the present study was to compare biological response of the subcutaneous connective tissue to a novel bilayer PCL (60 wt%)/SF (20 wt%)/SrC (20 wt%) membrane to a commercially available collagenous membrane.

Material and Methods

Eighteen male New Zealand rabbits were randomly divided into three groups, and all received subcutaneously the following materials: novel bilayer membrane, commercial membrane, and empty defect as control group, which were tested after 7, 14, and 28 days. The type and severity of inflammation, granulation tissue, and fibrous tissue were assessed.

Results

The connective tissue surrounding the implanted samples of each group exhibited the presence of similar cells close to the control groups. Statistical analyses showed no significant differences between the specimens in each time period.

Conclusions

In general, the novel bilayer nanocomposite membrane was a biocompatible material and produces a similar subcutaneous response compared to commercially available membrane. Besides, it demonstrated promise for guided bone regeneration technique for treating the osseous defects of oral and maxillofacial region.