Abstract
Diabetic ulcers (DUs), a devastating complication of diabetes, are intractable for limited effective interventions in clinic. Based on the clinical samples and bioinformatic analysis, we found lower level of CCN1 in DU individuals. Considering the accelerated proliferation effect in keratinocytes, we propose the therapeutic role of CCN1 supplementation in DU microenvironment. To address the challenge of rapid degradation of CCN1 in protease-rich diabetic healing condition, we fabricated a nanoformulation of CCN1 (CCN1-NP), which protected CCN1 from degradation and significantly raised CCN1 intracellular delivery efficiency to 6.2-fold. The results showed that the intracellular CCN1 exhibited a greater anti-inflammatory and proliferative/migratory activities once the extracellular signal of CCN1 was blocked in vitro. The nanoformulation unveils a new mechanism that CCN1 delivered into cells interacted with Eukaryotic translation initiation factor 3 subunit A (EIF3A) to downregulate autophagy-related 7 (ATG7). Furthermore, topical application of CCN1-NP had profound curative effects on delayed wound healing in diabetes both in vitro and in vivo. Our results illustrate a novel mechanism of intracellular EIF3A/CCN1/ATG7 axis triggered by nanoformulation and the therapeutic potential of CCN1-NP for DU management.