Study of the parameters of lyophilization and treatment of bovine pericardium by different methodologies for the inhibition of the calcification process

• Grant number: 17/16861-6
• Support Opportunities: Research Grants - Innovative Research in Small Business - PIPE
• Start date: December 01, 2018
• End date: August 31, 2019
• Field of knowledge: Interdisciplinary Subjects
• Principal Investigator: Bronislaw Polakiewicz
• Grantee: Bronislaw Polakiewicz
• Company: Biocollagen Ltda. - ME
• CNAE: Pesquisa e desenvolvimento experimental em ciências físicas e naturais ; Atividades profissionais, científicas e técnicas não especificadas anteriormente
• City: São José do Rio Preto
• Associated researchers: Janaina Aline Galvao Barros

Abstract

The lyophilization process when applied to human or animal biological tissues allows them to be preserved dry, facilitating their manipulation and storage, enabling sterilization with gamma rays or other means that ensure effective sterilization of the material, especially the elimination of slow virus , For subsequent use as medical-hospital products (grafts, prostheses, etc.). Lyophilization of biological tissues does not significantly alter the mechanical characteristics of the product and its reconstitution is simple. In the study of lyophilization, there is an interesting demonstration of the subtleties of water relations with biological materials. It is a non-equilibrium process, which when well conducted, is under kinetic control and involves metastable glassy states. Their understanding is linked to phase transitions as well as to rheological and structural phenomena. Although it is a sophisticated technology, it is far from mature, justifying a thorough investigation of each new product. Therefore, for its development and use, aiming at the final application of the process in state-of-the-art technological products, lyophilization demands multidisciplinary approaches, combining researchers from the different areas of knowledge, biological, biochemical, exact and medical, integrated for the same purpose Can unveil all the objectives proposed in this thematic project. Most living tissue consists of a matrix known as collagen and serves as a support for cells and several other striae. It is a fibrillar protein susceptible of modifications in radicals present in the lateral chains of some amino acids. In general, collagen is used clinically in the production of vascular prostheses and heart valves. The latter is usually obtained from bovine pericardium. Since the 1960s, collagen has undergone various forms of treatment in order to improve its properties such as flexibility, resistance and decrease in calcification in vivo. To obtain this result, glutaraldehyde has been the most widely used substance for several decades, but the treatments are also widely adopted by lyophilization, UV radiation and, more recently, by reaction with other promising chemical agents. (AU)