PREPARATION AND CHARACTERIZATION OF NANOHYDROXIAPATITE REINFORCED BIOPOLYMER-BASED SCAFFOLDS FOR BONE REGENERATION

BELLUZO, M.S.; CORTIZO, A.M.; MEDINA, L.F.; CORTIZO, M.S.

Maresias, Sao Paulo

Congreso; 14° Congresso da Sociedade Latino Americana de Biomateriais, Orgãos Artificiais e Engenharia de Tecidos ? SLABO; 2017

SLABO

Nowadays, tissue engineering is one of the research areas of fastest growing. The materials used in thisapplication must meet a large number of requirements, among which may be noted adequatebiodegradability according to the time required for regeneration of tissue, mechanical properties for theintended application, biocompatibility (adhesion, proliferation and differentiation osteoblasts),osteoinduction and no cytotoxicity. In our group we probed that ultrasound methodology is a useful methodto prepare a compatibilized blend of polyelectrolyte complexes (PEC), via creation of covalent bond thatgives more stability and better properties to the result scaffold. Despite the fact that this is a promisingmaterial for cartilage tissue regeneration, the mechanical properties are not accurate for bone tissuerepairing. In the present wok we aim to reinforced the mechanical properties of PEC based oncarboxymethyl cellulose (CMC) and chitosan (CHI) [1]. In order to improve the properties of the scaffolds,we prepared polymeric blends of CMC-CHI and add as a ceramic filler nano Hap (nano hydroxyapatite).Hap is a natural component of the bone and highly biocompatible, and has shown to improve the celladhesion and the enhancement of the osteogenic and mechanical properties in polymeric blends [2]. Thisnano Hap has an average diameter of 24,5 ± 0,2 nm, and was obtained by a procedure developed in ourlaboratory [3], combining mechanical/ultrasonic processing. The biocomposite was prepared from 1% w/vCHI solutions in 0.25% w/v acetic acid and 1% w/v CMC; the nano HA was added at different percentagesfrom 0 to 10%. The biocomposite samples were obtained by dropping CMC into a solution of CHI-HAunder constant stirring and in the presence of ultrasound. Finally, the composites were freeze-drying untilconstant weight was achieved. The morphology (by scanning electron microscopy), polyelectrolyteinteractions (by FTIR), swelling and mechanical properties of these composites were analyzed. In addition,we evaluate the in vitro cytotoxicity of the scaffolds using macrophage cells in culture, and evaluated NitricOxide production. The SEM results show a three-dimensional porous structure of the CHI-CMC-nanoHascaffolds with a mean pore size suitable for cell proliferation. FTIR-ATR analysis showed specificinteractions between the components in the biocomposite and the presence of the HA in the structure. Theswelling studies and mechanical test indicate that the composite displays hydrogel properties with enhancedmechanical properties. Finally, no cytotoxicity was found for any scaffold. These results let us concludedthat CMC-CHI-nanoHap composite is a promising candidate for bone regeneration.