Sustained delivery of MMP-9 siRNA via thermosensitive hydrogel accelerates diabetic wound healing

Biyun Lan,Chuan Yang,Junfeng Wu,Lexiang Zeng,Liming Zhang,Xiaoyi Wang,Meng Ren,Chenglin Pan,Na Li,Li Yan,Liqun Yang

doi:10.1186/s12951-021-00869-6

Abstract

Excessive expression of matrix metalloproteinase 9 (MMP-9) impedes healing of diabetic chronic wounds, thus wound dressing that could effectively inhibit the expression of MMP-9 offers significant clinical translation for diabetic wound healing. Herein, a hybrid hydrogel dressing was developed for localized and sustained delivery of MMP-9 siRNA (siMMP-9). siMMP-9 was complexed with Gly-TETA (GT), the GT/siMMP9 complex was then loaded into a thermosensitive hydrogel based on Pluronic F-127 (PF) and methylcellulose (MC). In vitro, this hybrid hydrogel dressing exhibited negligible cytotoxicity, prolonged the release of GT/siMMP-9 for up to 7 days, and significantly reduced MMP-9 expression. In vivo assessment in diabetic rats demonstrated that hydrogel provided localized and sustained delivery via the thermosensitive controlled release of entrapped GT/siMMP-9 into wound tissues for 7 days, resulting in dramatic MMP-9 silencing which significantly improved diabetic wound closure. This hybrid hydrogel dressing exhibited excellent biocompatibility, with no observed systemic toxicity in rats. Taken together, the hybrid hydrogel dressing may constitute an effective and biocompatible means of enhancing diabetic wound healing through effective silencing of the MMP-9 gene, and this hydrogel delivery system also offers a platform for in vivo delivery of siRNA for the treatment of other diseases.

Highlights

Diabetic chronic wounds are a growing problem worldwide as it is one of the most serious complications in diabetic patients [1]
The sequence of human siMMP-9: 5’-CUA UGG UCC UCG CCC UGA ATT-3’, antisense: 5’-UUC AGG GGC GAC CAU AGT T-3’; the sequence of rat siMMP-9: 5’-GGG CUU AGA UCA UUC UUC ATT-3’, antisense: 5’-UGA AGA AUG AUC UAA GCC CAG-3’; the sequence of negative control Small interfering RNA (siRNA): 5’-UUC UCC GAA CGU GUC ACG UTT-3’, antisense: 5’-ACG UGA CAC GUU CGG AGA ATT-3’; siRNA labeled with FAM was abbreviated as siFAM; siRNA labeled with Cy5 was abbreviated as siCy5
Characterization of GT and GT/siMMP‐9 complex The successful synthesis of GT was confirmed by Fourier transform infrared (FTIR) and 1H nuclear magnetic resonance (NMR)

Summary

Introduction

Diabetic chronic wounds are a growing problem worldwide as it is one of the most serious complications in diabetic patients [1]. With limited regenerating capacity after injury, diabetic wounds adversely affect the quality of life (QOL) of patients; and the 5 year-survival is only 29 –50 % [2, 3]. In the United States alone, more than 110,000 diabetes-related amputations occur per year, Wound healing of the skin requires a well-orchestrated integration of various physiologic factors and biological events, especially the balance between the deposition of extracellular matrix (ECM) and their. MMP-9 levels are known to be elevated in various diseases, including chronic non-healing wounds, myocardial infarction, stroke and cancers [7,8,9,10]. Excessive activation of MMP-9 leads to the breakdown of local ECM, and cell migration is impaired without the scaffold provided by ECM. Since excessive MMP-9 has been demonstrated to be a major pathogenic contributor in delayed diabetic wound healing, down-regulation of MMP-9 expression in local diabetic wounds could be a promising method of facilitating the healing of diabetic wounds

Methods

Results

Discussion

Conclusion