Hollow polydopamine nanoparticles loading with peptide RL-QN15: a new pro-regenerative therapeutic agent for skin wounds

Background: Although the treatments of skin wounds have greatly improved with the increase in therapeutic methods and agents, available interventions still cannot meet the current clinical needs. Therefore, the development of new pro-regenerative therapies remains urgent. Owing to their unique characteristics, both nanomaterials and peptides have provided novel clues for the development of pro-regenerative agents, however, more efforts were still be awaited and anticipated. Results: In the current research, Hollow polydopamine (HPDA) nanoparticles were synthesized and HPDA nanoparticles loading with RL-QN15 (HPDAIR) that was an amphibian-derived peptide with obvious prohealing activities were prepared successfully. The characterization, biodistribution and clearance of both HPDA nanoparticles and HPDAIR were evaluated, the loading efficiency of HPDA against RL-QN15 and the slow-releasing rate of RL-QN15 from HPDAIR were also determined. Our results showed that both HPDA nanoparticles and HPDAIR exerted no obvious toxicity against keratinocyte, macrophage and mice, and HPDA nanoparticles showed no prohealing potency in vivo and in vitro. Interestingly, HPDAIR significantly enhanced the ability of RL-QN15 to accelerate the healing of scratch of keratinocytes and selectively modulate the release of healing-involved cytokines from macrophages. More importantly, in comparison with RL-QN15, by evaluating on animal models of full-thickness injured skin wounds in mice and oral ulcers in rats, HPDAIR showed significant increasing in the pro-regenerative potency of 50 and 10 times, respectively. Moreover, HPDAIR also enhanced the prohealing efficiency of peptide RL-QN15 against skin scald in mice and full-thickness injured wounds in swine. Conclusions: HPDA obviously enhanced the pro-regenerative potency of RL-QN15 in vitro and in vivo, hence HPDAIR exhibited great potential in the development of therapeutics for skin wound healing.

Automated summary

Although the current treatments for skin wounds have improved, there is still a need for new pro-regenerative therapies. Nanomaterials and peptides have provided novel opportunities for developing pro-regenerative agents, with HPDA significantly enhancing the potency of RL-QN15 in promoting skin wound healing.