A “sandwich” cell culture platform with NIR-responsive dynamic stiffness to modulate macrophage phenotypes
Peiqi Yuan, Yilun Luo, Yu Luo, Lie Ma
Abstract
) diffused through the middle layer of the IR780-mixed phase change material (PCM) due to the photothermal effect of IR780, resulting in an increase of hydrogel stiffness in situ by the crosslinking of the upper layer of the hyaluronic acid-sodium alginate hydrogel (MA-HA&SA). The up-regulation of inducible nitric oxide synthase (iNOS) and tumor necrosis factor-α (TNF-α) was quantified by immunostaining and enzyme-linked immune sorbent assay (ELISA), respectively, indicating the transformation of macrophages from the anti-inflammatory to pro-inflammatory phenotype under dynamic stiffness. The nuclear Yes-associated-protein (YAP) ratio positively correlated with the shift of the macrophage phenotype. The modulation of macrophage phenotypes by stiffness-rise without the stimuli of cytokines offers an effective and noninvasive strategy to manipulate immune reactions to achieve optimized healing or therapeutic outcomes.