Development of chondrocyte ‐laden alginate hydrogels with modulated microstructure and properties for cartilage regeneration

This study aims to investigate the applicability of sodium citrate buffer (SCB) as a culture medium supplement for modulating the microstructure of alginate microbeads to provide a favorable microenvironment for chondrogenic induction. The chondrocyte-laden microbeads, with and without TGF- β3 incorporation, were produced through an encapsulator. The obtained small-sized microbeads (~300 μm) were exposed to a treatment medium containing SCB, composed of varied concentrations of sodium citrate (1.10 – 1.57 mM), sodium chloride (3.00 – 4.29 mM), and ethylenediaminetetraacetic a cid (0.60 – 0.86 mM) to partially degrade their crosslinked structure for three days, followed by culture in a normal medium until Day 21. SEM micrographs demonstrated a loose hydrogel network with an enhanced pore size in the SCB-treated microbeads. Increasing the concentration of SCB in the tr eatment medium reduced the calcium content of the microbeads via a Na+/Ca2+ exchange process and improved the water absorption of the microbeads, resulting in a higher swelling ratio. All the tested SCB concentrations were non-cytotoxic. Increases in aggrecan and type II collagen gene expression and their corresponding extracellular matrix accumulation, glycosaminoglycans, and type II collagen were vividly detected in the TGF- β3-containing microbeads with increasing SCB concentrations in the treatment medium. Our findings highlighted that the combination of SCB treatment and TGF-β3 incorporation ...
Source: Biotechnology Progress - Category: Biotechnology Authors: Tags: RESEARCH ARTICLE Source Type: research