فهرست مطالب farzane jabari

Designing and fabrication of biodegradable and bioactive membranes are the important issues in guided bone regeneration while these membranes should maintain their structural integrity during repair, have the required mechanical, physical and biological properties and selective permeability. One of the approaches to achieve this purpose is the fabrication of composite membranes based on biopolymers.  In this research, the fabrication and characterization of composite membranes composed of chitosan-silk fibrobin and polyvinyl alcohol have been performed.chitosan solution and fibroin- polyvinyl alcohol solution were mixed in different ratio and membranes were fabricated by solvent casting method. Mechanical properties such as tensile strength and ultimate strain percentage and physical properties including water absorption and degradation rate of membranes were investigated.  The FTIR spectrum of the extracted fibrobin showed peaks at 1650 cm-1, 1530 cm-1, and 1244 cm -1. The XRD and SEM images showed that the synthesized fibrin has the structure of beta plates. The results of physical and mechanical properties of membranes showed that the presence of fibroin in the composition increases the mechanical strength. Increasing the amount of chitosan in the composition increased the water absorption and degradation rate of membranes.  Fibroin is a suitable polymer for increasing mechanical strength, controlling the degradation rate, improving the water absorption ability and is so biocompatible. Solvent casting method with controlling the viscosity of solution and solvent evaporation rate is appropriate method for fabrication the membranes.

The Guided Bone Regeneration (GBR) treatment concept advocates that regeneration of osseous defects is predictably attainable via the application of occlusive membranes, which mechanically exclude non-osteogenic cell populations from the surrounding soft tissues, thereby allowing osteogenic cell populations originating from the parent bone to inhabit the osseous wound. The use of membrane to exclude non-osteogenic cells, is a key principle of guided bone regeneration. A large number of membranes have been evaluated in clinical and experimental studies. The object of this study was to review the literature regarding guided bone regeneration and all types of membranes that were used in this technique. 72 articles between the years 1968 through the 2016 from PubMed, Medline and Google Scholar using the related keywords, were selected. Finally, we concluded that the modification of mechanical and physico-chemical properties of membranes could improve the process of new bone growth. However, determination of the exact role of membrane porosity in this process, still needs to be clarified. Optimization the chemical composition of membrane with the focus and attention to obstructive property and bioactivity, is an important point in this research field. Various factors such as flexibility, mechanical strength and degradation rate determine the type of membrane used for bone tissue regeneration