Hydroxyl Groups Induce Bioactivity in Silica/Chitosan Aerogels Designed for Bone Tissue Engineering. In Vitro Model for the Assessment of Osteoblasts Behavior

Polymers

Gonzalo Pinaglia-Tobaruela¹  DeseadaMaríade los Santos²  Maríade las Virtudes Reyes-Peces³  JoséIgnacio Vilches-Pérez³  Nicolásde la Rosa-Fox³  Antonio Perez-Moreno³  Manuel Piñero³  Emiliode la Orden³  Mercedes Salido³ 

[1] Department of Histology, SCIBM, Faculty of Medicine, University of Cadiz, 11004 Cádiz, Spain;Department of Physical Chemistry, Faculty of Science, University of Cadiz, 11510 Cádiz, Spain;Instituto de Investigación e Innovación Biomédica de Cádiz (INIBICA), 11009 Cádiz, Spain;

关键词: aerogels;    biomaterials;    fracture toughness;    hydroxyapatite (HAp);    bone tissue engineering;    osteoinduction;   

DOI  :  10.3390/polym12122802

来源: DOAJ

【 摘 要 】

Silica (SiO₂)/chitosan (CS) composite aerogels are bioactive when they are submerged in simulated body fluid (SBF), causing the formation of bone-like hydroxyapatite (HAp) layer. Silica-based hybrid aerogels improve the elastic behavior, and the combined CS modifies the network entanglement as a crosslinking biopolymer. Tetraethoxysilane (TEOS)/CS is used as network precursors by employing a sol-gel method assisted with high power ultrasound (600 W). Upon gelation and aging, gels are dried in supercritical CO₂ to obtain monoliths. Thermograms provide information about the condensation of the remaining hydroxyl groups (400–700 °C). This step permits the evaluation of the hydroxyl group’s content of 2 to 5 OH nm⁻². The formed Si-OH groups act as the inductor of apatite crystal nucleation in SBF. The N₂ physisorption isotherms show a hysteresis loop of type H3, characteristic to good interconnected porosity, which facilitates both the bioactivity and the adhesion of osteoblasts cells. After two weeks of immersion in SBF, a layer of HAp microcrystals develops on the surface with a stoichiometric Ca/P molar ratio of 1.67 with spherulite morphology and uniform sizes of 6 μm. This fact asserts the bioactive behavior of these hybrid aerogels. Osteoblasts are cultured on the selected samples and immunolabeled for cytoskeletal and focal adhesion expression related to scaffold nanostructure and composition. The initial osteoconductive response observes points to a great potential of tissue engineering for the designed composite aerogels.

【 授权许可】

Unknown