The efficacy of myocardial regeneration strategies for myocardial infarction (MI) is significantly compromised by the complex structure and microenvironment of the myocardium. Although tissue engineering strategies based on cell therapy and/or pro-angiogenesis can somewhat improve cardiac function, the lack of proper myocardial materials that can withstand sustained deformability and adaptable mechanical properties severely affects myocardial wall integrity, systolic-diastolic cycles, and regeneration. Herein, we developed an integrated single “all-in-one” in situ dual crosslinking conductive hydrogel with favorable treatment properties termed as MaHA/B-G-SH/Fe 3+ by ionic interactions and chemical covalency based on modified hyaluronic acid (HA), gelatin (G), and Fe 3+ . The resulting dual crosslinking dynamic hydrogel not only provides self-healing and mechanical properties adapted to the myocardial systolic-diastolic cycle with simultaneous electrical signal transmission to fibrous islands and normal tissue, but also leads to significant increase of the myocardial wall thickness very close to that of normal myocardium upon one single injection with complete degradation within 28 days. Notably, the hydrogel covalently conjugated with a tailored peptide sequence of GGR-KLT and encapsulated with bone mesenchymal stem cells (BMSCs) was further used for in situ injection in a rat MI model, which exhibited (i) efficient inhibition of excessive matrix degradation dependent on early MMP-2 expression, (ii) triggered on-demand release of KLT for at least 14 days and significant promotion of angiogenesis, and (iii) synergistic BMSCs considerably enhanced myocardial regeneration within 28 days. Taken together, the dual crosslinking conductive hydrogel-mediated synergistic peptide and cell therapy provides comprehensive recovery and regeneration of the structure and function of the injured myocardium, thus demonstrating great potential for clinical translations.
Individuals with diabetes frequently face serious challenges, including delayed wound healing and increased risk of infection. Notably, the regeneration of hair follicles plays a crucial role in accelerating diabetic skin damage repair, reducing the risk of infection, and enhancing overall skin health. Research has predominantly emphasized the re-epithelialization of diabetic wounds, with a paucity of in-depth studies on hair follicle regeneration. In the current study, we explored the effects of a bioactive amphibian-derived peptide, Cy RL-QN15 , on promoting hair regeneration in a diabetic skin model. In vivo experiments demonstrated that local treatment with Cy RL-QN15 not only accelerated wound healing of scalded skin on the backs of diabetic Kunming (KM) mice but also improved growth of damaged hair follicles. Additionally, back-shaved diabetic C57BL/6 mice showed a significant increase in the growth of newly formed hair after 28 days of continuous Cy RL-QN15 treatment. Further analysis indicated that the hair-regenerating effects of Cy RL-QN15 were closely associated with the proliferation and migration of hair follicle stem cells (HFSCs). Cy RL-QN15 enhanced intracellular β-catenin expression by binding to the Frizzled-7 receptor on the surface of HFSCs. The up-regulation in β-catenin modulated the levels of downstream proteins, such as c-MYC, Cyclin D1, and Lef1, ultimately inducing hair regeneration. This study not only reveals the robust effects of the bioactive peptide Cy RL-QN15 in hair follicle regeneration but also provides novel avenues for the development of more targeted and effective therapeutics for diabetic wound healing in the future.
危险品化学品经营许可证（带存储）