Sr Ions Influence on Hydroxyapatite Biomineralization using Self-Templated Hierarchical Structures of Collagen-Like Peptide Amphiphiles

• Grant number: 16/19677-9
• Support Opportunities: Scholarships abroad - Research Internship - Master's degree
• Start date: January 20, 2017
• End date: July 19, 2017
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Ana Paula Ramos
• Grantee: Marcos Antonio Eufrásio Cruz
• Supervisor: Seung-Wuk Lee
• Host Institution: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Institution abroad: University of California, Berkeley (UC Berkeley), United States
• Associated to the scholarship: 15/08774-0 - Modification of Ti surfaces by Langmuir-Blodgett hybrid films containing biominerals and strontium ranelate to promote the controled Sr2+ release, BP.MS

Abstract

The continuing interest of strontium (Sr2+) for bone tissue engineering purposes is related to its remarkable effects in the treatment of osteoporosis. In this sense, several biomaterials have been developed in order to create systems that promote the controlled delivery of Sr2+ to stimulate positive effects on bone metabolism. However, the intrinsic effect of this cation on the bone structure has been little explored, since most studies are concerned on clinical and biological effects of Sr2+ administration. So, there is a need in understanding the effect of Sr2+ incorporation into de hydroxyapatite (HAp) structure, once this biomineral is the main inorganic compound of bone tissue. For this, we propose the use of self-templated hierarchical structures of collagen-like peptide amphiphiles (CLPA) as model of the organic interface of bone tissue and investigate the Sr2+ influence on HAp biomineralization. Collagen is a protein found on mineralized tissues, so create systems that mimetize its structure is an important advance in understand biomineralization at organic-inorganic interface level. The self-assembly of CLPA is a pioneer technique developed by Prof. Seung-Wuk's group that allows creation of hierarchical structures with high organization degree, mimetizing the organic matrix of bone tissue. This project will be the first effort to investigate the Sr2+ incorporation into HAp crystal structure at molecular level. Self-assembled CLPA structures will be mineralized using biomimetic HAp-precursor solutions containing different Sr2+ concentrations, in order to evaluate the incorporation of this cation into the HAp crystal structure. Several techniques will be used in order to gain information about crystal structure, composition and morphology; strength and stability of organic-inorganic matrix related to Sr2+ incorporation. This project will add knowledge about the importance of collagenous matrix on the effect of Sr2+ incorporation on the bone tissue, allowing an advance in the biomineralization chemistry and design of Sr-based bioinspired materials.