Preliminary Study On Biocompatibility Of Bacterial Cellulose Tissue Engineering Scaffold

In recent years, with the development of materials science, life science, and related chemistry, physics, tissue engieering research has achieved rapid progress, which the ultimate goal is to co-culture functional cells and biodegradable three-dimensional scaffolds (artificial extracellular matrix) in vitro to build living tissues and organs that repair, improve and regenerate disordered organizations and function. In order to extend human life and improve their health.Scaffold materils are essential to tissue engineering. It can not only promote cell adhesion and proliferation, but also form a new organization with a specific function. Tissue engineering scaffold should have good tissue compatibility and biocompatibility, excellent mechanical properties and so on.Bacterial cellulose(BC) was recognized as an outstanding performance of new biological material in the world. It has good network structure of nanfibers, certain pore size and porosity, high chemical purity and degree of crystallinity, good elastic modulus and strong hydration, higher ability of anti-tearing force and anti-tension, well biodegradability and biocompatibility, as well as easily to control in the biosynthesis process.Bacterial cellulose-chitosan(BCC) is a composite material that combines the advantages of each material, overcome the worse mechanical properties of chitosan. This composite material is not only optimized the BC and chitosan's biological activity and physical properties, but aslo improve the dimensional stability and mechanical strength of chitosan.In this study, Keratinocyte(KC) was cultured in vitro, then combined cultued with BC and BCC. By hemolysis test, systemic allergy test, thermal test, retina irritation test and acute toxicity test to have an prelininary evaluation on the biocompatibility of the two materials, and to provide a reference for tissue engineering applications.This study include four elements:1. KC inoculated to one side of BC, and observed the form of the cells-scaffold composite by using scanning electron microscope(SEM). The results show that KC attached to the BC scaffold closely and have good cell structures. When cultured for five days, KC not only adhere to scaffold closely, aslo have tight junction between cells. These indicate that BC has well cell compatibility, aslo can promote cell adhesion and proliferation.2. KC inoculated to one side of BCC, and observed the form of the cells-scaffold composite by SEM. The results show that KC aslo can grow on the surface of BCC. These indicate that BCC has well cell compatibility, and also can promote cell adhesion and proliferation.3. By hemolysis test, systemic allergy test, thermal test, retina irritation test and acute toxicity test to have an prelininary evaluation on the biocompatibility of BC. During the hemolysis test, combined BC and the rabbit blood, using spectrophotometry to survey the absorbance at 545nm, in order to determine whether BC may cause hemolysis response. The results show that hemolysis rate of BC is 0.16%,<5%, meet the requirement of hemolysis test. The BC was in the form of extract injected into animals or instill into eyes directly, in order to determine whether BC has characteristic of pyrogenic, irritating and toxic. The results show that BC did not occur dry cough, shivering, breathing difficultity and other symptoms, non-allergenic. The fluctuation of temperature that the rabbits which injected BC extract did not exceed 1.6℃, so non-pyrogenic. And the rabbits'eyes did not appear red, bleeding and other symptos. The status and body weight is not affected by the BC extract either. BC has well biocompatibility, non-hemolytic, non-themal, non-pyrogenic, non-irritating and non-toxicity.4. By hemolysis test, systemic allergy test, thermal test, retina irritation test and acute toxicity test to have an prelininary evaluation on the biocompatibility of BCC. The results show that BCC has non-hemolytic, non-themal, non-pyrogenic, non-irritating and non-toxicity.Above all, the results show that KC was attached to the scaffold of BC and BCC, these two materials can promote cell growth and proliferation. These indicate that both materials have excellent biocompatibility. Two kinds of materials in the form of extract injected into animals, the two materisls both non-hemolytic, non-themal, non-pyrogenic, non-irritating and non-toxicity. Both BC and BCC can be as scaffold materials applied in tissue engineering.