Fabrication of Chitosan/Poly (vinyl alcohol)/Carbon Nanotube/Bioactive Glass Nanocomposite Scaffolds for Neural Tissue Engineering

Tissue engineering in medical engineering has been always raised and expanded for the repair and replacement of damaged or destroyed tissues and organs operations. Nerve regeneration is a precious treatment for human health because it is directly related to the quality of human life. It is quite clear that human central nervous system (CNS) in adults is unable to repair itself after being damaged or injured [1,2]. Recently, tissue engineering has offered a new therapy as an alternative for the traditional method of graft including the use of polymeric or composite biomaterials with or without cells. Polymers can be used as scaffolds for providing cell adhesion, maintenance, and differentiation without making the delay in cell differentiation [3]. Poly (vinyl alcohol) (PVA) is known as a biocompatible and hydrophilic polymer with proper chemical and thermal stability and also excellent tensile strength and flexibility [4,5]. Chitosan is a linear polymer with a polysaccharide structure and obtained from hydrolyzing natural polymer of chitin [6]. Chitosan is also one of the biodegradable and biocompatible polymers with human body and has certain features appropriate for many fields such as biological, medical, drug delivery, and gene therapy [7]. Chitosan polymer composites and poly (vinyl alcohol) have been used in neural tissue engineering [1,4,7]. The proper rate of degradation, acceptable mechanical properties, and high spinning capability are the main reasons for using these polymers in fabricating neural tissue engineering scaffolds [5,6]. The most important requirement of a tissue engineering scaffold is having proper mechanical properties to be able to tolerate dynamic and static stress of body fluid environment. Neural tissue engineering scaffolds are not exempt from this. Carbon nanotubes have an important and special place among materials with high potential to be used in micro/nano systems. Notable properties of carbon nanotubes such as high conductivity, mechanical strength, low density, and high stability have led them to be considered by the researchers in recent years. Of these, high conductivity and good mechanical strength have expanded their use in neural tissue engineering scaffolds. In recent years, researchers have mentioned the use of carbon nanotubes and their roles in neural tissue engineering scaffolds as a part of conductors and directors of neural signals [1]. Scientists have found that nonwoven single-walled carbon nanotubes have more scaffold properties than any other types. So, cell adhesion and proliferation ability increase significantly [8,9]. This finding opens a new way of using nanotubes in repairing cell damages. Tight connections of osteoblasts to nanotubes scaffolds formed during the cultivation have been approved before [10-12]. Bio ceramics are known and famous groups among biomaterials. High corrosion resistance, biocompatibility, and proper biological properties are major advantages of these materials than metal and polymer ones [13]. Among all bioactive materials, the best bioactive treatment belongs to the bioactive glass containing a group of glass compounds which bond to the tissue in a short time. The first reports of in vitro studies about bioactive glasses published in 1971 [14]. Integrated pieces of bioactive glasses (45S5 Bio glass) were placed in tibia of a rat and not only didn’t make any inflammatory effect, but also created a substantial connection with the surrounding bone tissue [15]. The capability of bioactive glasses in repairing soft tissue and their potential effect on tissues such as neural tissues are mentioned in some Volume 4 Issue 3 2016