Self-assembled insulin-like growth factor 1 peptides induce adipose stem cell differentiation to repair cartilage injury

Tissue engineering using adipose-derived mesenchymal stem cells (ADSCs) promotes the regeneration of articular cartilage. However, insulin-like growth factor 1 (IGF-1), which is used to induce the differentiation of ADSCs into chondrocytes during treatment, is prone to instability and short tissue retention. Nap-FFG-GYGSSSRRAPQT was used as an IGF-1 mimicking molecule. MTT and CCK-8 assays were performed to evaluate the proliferation ability of ADSCs. QRT-PCR and Western blot assays were used to assess the expression of cartilage-related genes. International Cartilage Regeneration and Joint Preservation Society (ICRS) scoring was used for the evaluation of cartilage repair. Repaired tissues were analyzed by hematoxylin-eosin, Safranin-O and immunohistochemical staining. Nap-FFG-GYGSSRRAPQT stimulated the proliferation and migration of ADSCs through the activation of IGF-1 receptor. Gel Nap-FFG-GYGSSRRAPQT treatment upregulated the expression of cartilage-related genes in ADSCs. ADSCs/Gel Nap-FFG-GYGSSRRAPQT treatment significantly promoted the regeneration of cartilages. Self-assembled IGF-1 peptide, Nap-FFG-GYGSSRRAPQT, can induce ADSC differentiation and proliferation to repair cartilage injury.