Subcutaneous tissue reaction after implantation of a new biomaterial composed by bacterial cellulose embedded with hydroxyapatite

• Grant number: 13/21562-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): January 01, 2014
• Effective date (End): December 31, 2014
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Angela Mitie Otta Kinoshita
• Grantee: Karla Veronês Massari
• Host Institution: Centro de Ciências da Saúde. Universidade do Sagrado Coração (USC). Bauru , SP, Brazil

Abstract

A biomaterial that has been studied to compose bone substitutes is bacterial cellulose (BC). BC is mainly obtained from cultures of gram-negative bacteria such as Acetobacter xylinum (Gluconacetobacter xylinus). Has a high modulus of elasticity and tension, due to the high crystallinity of nanofiber network dimensional presented in its structure. The large number of hydroxyl groups on the surface of BC enables the synthesis of nanoparticles. Thus, nanoparticles of hydroxyapatite (HAp ) has been synthesized in the matrix BC , constituting a new biomaterial BC / HAp that can be used as a bone substitute . One of the first steps in testing new materials for clinical use are the biocompatibility tests. Among these, the tissue response to subcutaneous implantation provides important information about the general response of the organism through the inflammatory pattern observed. Thus, the study of tissue response of this new biomaterial is necessary and valuable for future applications as bone substitute. Eighteen male rats ( Rattus norvegicus, Wistar ) will be used which suffer surgically 3 incisions on the back for subcutaneous implantation of materials to be tested: CB, CB / HAp and PTFE ( polytetrafluoroethylene ) a commercial biocompatible. After 7, 15 and 60 days, 6 animals will be euthanized, tissue reaction will be microscopically analyzed observing the presence of necrosis, fibrous capsule, inflammatory cells. Six images will be recorded for around the implanted materials and in each slide the number of mononuclares, poliformonucleares and giant cells will be couted, as well as the thickness of the fibrous capsule. Quantitative data will be evaluated in accordance with a predetermined score and comparison of results will be conducted by the nonparametric Kruskal- Wallis and will be considered statistically different when P < 0:05.