Utilization of Lipid Nanoparticles-mRNA Formulations to Eliminate ROS and Accelerate Diabetic Wound Healing

Diabetic wounds are common complications in patients with hyperglycemia, characterized by high incidence and recurrence rates, causing substantial global economic losses. Existing treatments, including wound offloading and growth factor therapy, although shown to shorten healing time in clinical trials, their widespread application is limited by cost and potential side effects. Therefore, there is an urgent need to develop a more effective, safe, and convenient diabetic wound management method.

In the complex wound microenvironment, the major treatment challenges stem from the uncontrolled accumulation of reactive oxygen species (ROS) and persistent inflammation. This pathological microenvironment leads to excessive oxidative stress and ischemic angiogenesis, delaying wound healing. The aim of this study is to develop reactive ROS-responsive lipid nanoparticles (LNPs) and mRNA formulations to regulate the ROS and inflammatory microenvironment within the wound, thereby accelerating diabetic wound healing.

Research Overview

This article, collaboratively completed by Siyu Wang, Yuebao Zhang, Yichen Zhong, and other researchers from the Icahn School of Medicine at Mount Sinai and Ohio State University, was published in the Proceedings of the National Academy of Sciences (PNAS) on May 21, 2024. The article detailed a novel treatment method based on ROS-clearing lipid nanoparticles and mRNA formulations, which can significantly accelerate diabetic wound healing.

Research Background and Motivation

The chronic, non-healing wounds of diabetic patients have complex pathological mechanisms, primarily characterized by uncontrolled accumulation of ROS and persistent inflammatory responses. These excessive ROS lead to oxidative stress and inactivation of growth factors, significantly reducing the wound’s healing ability. On the other hand, M1-type macrophages in pathological wounds continuously release pro-inflammatory cytokines, while M2-type macrophages promote wound repair through anti-inflammatory responses. Therefore, regulating the inflammatory microenvironment within the wound, including ROS clearance and macrophage phenotype transformation, could be an effective method for diabetic wound healing.

Research Process

Synthesis and Preparation of TS LNP for mRNA Delivery

The research team designed ROS-responsive trisulfide-derived lipid nanoparticles (TS LNP) for encapsulating interleukin-4 (IL4) mRNA to achieve ROS clearance and macrophage phenotype regulation. Firstly, the team synthesized ionizable lipids containing trisulfide bonds and constructed a library of 98 different lipid molecules using combinational chemistry, evaluating their delivery efficiency in macrophages.

Experimental Optimization and Screening

The team tested and screened the mRNA delivery efficiency of each LNP based on bioluminescence intensity. Results showed that TS2 LNP exhibited the highest mRNA delivery efficiency, 30 times higher than the clinically used MC3 LNP. Next, the team further optimized the TS2 LNP formulation, ultimately determining the optimal lipid component ratio, significantly improving mRNA delivery efficiency and particle stability.

In Vitro Cell Experiments

In vitro experiments demonstrated that TS2 LNP could effectively clear ROS within cells, protecting fibroblasts from oxidative stress damage. Additionally, TS2 LNP successfully promoted the transformation of macrophages from M1 to M2 phenotype, achieving immune regulation within the wound microenvironment.

Animal Model Verification

In a diabetic mouse (db/db mice) model, the team applied TS2 LNP-IL4 mRNA formulations loaded into hydrogels to diabetic wounds via a single-dose application. Results indicated that the TS2-IL4 LNP-mRNA group exhibited significantly accelerated wound healing efficiency compared to untreated, free IL4 mRNA, and MC3-IL4 LNP-mRNA groups, halving the healing time.

Main Results and Conclusions

The study indicated that TS2 LNP-IL4 mRNA demonstrated excellent ROS clearance capability and optimized macrophage phenotype regulation both in vitro and in vivo. By improving the wound microenvironment, the formulation significantly accelerated diabetic wound healing. Furthermore, compared to other clinically used mRNA delivery systems, TS2 LNP provided superior mRNA delivery efficiency and higher cellular protection.

Scientific and Application Value of the Research

This study not only offers a safe, effective, and convenient new strategy for treating diabetic wounds but also opens new possibilities for treating other chronic or acute wounds. The innovative aspect of the research lies in combining ROS-responsive nanoparticles with mRNA formulations, fundamentally regulating the pathological wound microenvironment, significantly enhancing clinical application potential and therapeutic efficacy.

Key Highlights

1. Innovative Treatment Strategy: By designing and synthesizing reactive ROS-responsive lipid materials, formulating them into TS LNP for mRNA delivery, the study successfully addressed major challenges in diabetic wound treatment.
2. Effective ROS Clearance: TS LNP exhibited outstanding ROS clearance capability both in vitro and in vivo, significantly enhancing cell survival and wound healing speed.
3. Immune Microenvironment Regulation: By delivering IL4 mRNA, the study achieved successful transformation of macrophages from M1 to M2 phenotype, further promoting wound healing and tissue reconstruction.

Summary

This study innovatively combined ROS-responsive nanoparticles with mRNA delivery systems, providing new ideas and methods for diabetic wound treatment. The results indicated that TS2 LNP-IL4 mRNA not only possesses significant ROS clearance and immune regulation capabilities but also demonstrated remarkable wound healing acceleration effects in animal models. This scientific discovery is expected to play an important role in future clinical applications, benefiting more diabetic patients.