Figure 8.

An injectable nanofiber hydrogel to deliver an aging-related miRNA to rejuvenate impaired AC: (a) RAD (RADA) and SKP (SKPPGTSS) peptides self-assemble to form a stable nanofiber hydrogel with aging-related agomir-29b-5p distributed inside by adjusting the pH value to neutral, (b) molecular docking analysis of RAD or SKP peptide interacted with agomir-29b-5p, (c) the recruitment process pattern of SMSCs during AC repair, (d) images and cell quantification of Transwell bottom membrane stained with crystal violet after 24 h to monitor SMSCs recruitment in vitro, (e) Toluidine blue, Alcian blue, and immunofluorescence staining of COL2A1 and COL1A1 in SMSCs pellets after 14-day culture on RAD, RAD@miR, SKP, and SKP@miR, (f) qRT-PCR analysis of gene expression of chondrogenesis-related and osteogenesis-related genes in SMSCs pellets. Values were normalized to β-actin levels, and RAD group was used as the control group. Statistical analysis was performed using one-way ANOVA. *p < 0.05 and **p < 0.01. Reproduced from Zhu et al.⁴⁹