Fabrication and evaluation of hydroxyapatite-chitosan scaffold via simulated body fluid biomimetic mineralization

Abstract

This research aimed to fabricate a hydroxyapatite (HA)-chitosan scaffold via simulated body fluid (SBF) biomimetic mineralization and determine how mineralization time affects scaffold construction and cell compatibility. The HA-chitosan scaffolds were fabricated by freeze-drying technique and then subjected to precalcification, also known as alternative soaking method. Afterward, precalcificated scaffolds were placed into the SBF to conduct the mineralization process. Mineralization time was set at 7, 14, and 21 days, corresponding to three experimental groups. Pure chitosan scaffolds acted as the control group, and the physical and chemical properties of the four groups were tested. Osteogenic-induced adipose-derived stem cells (ADSCs) were seeded into the scaffolds to investigate the scaffolds' cell compatibility. The mineral substance of the 14-day group exhibited a uniform distribution. The crystal composition of the mineral substance suited the HA's features. The compressive elastic modulus increased along with the extension of mineralization time. The 21-day group showed a statistically significant increase in compressive elastic modulus compared with the control group (P < 0.05). The cell proliferation level of the 14-day group was significantly the highest among the three experimental groups (P < 0.05). The calcium ion and the type I collagen had the highest secretion amount when the cells were seeded into the 14-day group. The SBF biomimetic mineralization method can be used to fabricate HA-chitosan bone-tissue-engineering scaffolds. The biological compatibility, as well as the chemical and physical properties, reached the optimum levels at day 14.