A hydrogen peroxide-sensing liposomal hydrogel for molecular diagnostics in diabetic wounds

People involved

Gabriela Manrique (PhD fellow funded by the PRC) - Université de Montréal

Katia Cherifi (MSc student) - Université de Montréal

Abstract

Diabetic foot ulcers (DFUs) are a serious complication of diabetes. DFUs affect 15-25% of patients with diabetes in their lifetime and are a major cause of amputations in industrialized countries.1) The standard of care in DFU diagnostics is a macroscopic evaluation (wound size, depth, signs of infection).2) In the future, molecular diagnostics promise to enable molecular disease staging, evidence-based treatment selection, and assessment of treatment success. Recent advances in the understanding of diabetic wound healing indicate the key role of hydrogen peroxide (H₂O₂) in the pathophysiology of diabetic wound healing.3)4)5) H₂O₂ is therefore a particularly promising molecular diagnostic target in DFU.

The overall goal of this research proposal is to develop fluorescent H₂O₂-sensing diagnostic wound dressing, and to test it in diabetic mouse wounds using a portable fluorometer. The dressing is composed of H₂O₂-sensing liposomal reaction compartments dispersed in an alginate hydrogel. After administration on the wound, H₂O₂-rich wound fluid diffuses into the hydrogel. H₂O₂ enters the liposomal lumen where it is used by horseradish peroxidase (HRP) to oxidize the near-infrared fluorescent dye sulfo-cyanine 7 (S7), which results in an H₂O₂ concentration-dependent loss of fluorescence. The fluorescence decrease is detected by a portable fluorometer. To prolong shelf-life, a cryo- and lyoprotectant-containing formulation and a lyophilization process will be developed to dry the liposomal hydrogel with minimal cargo release. This highly specific in situ wound H₂O₂ assay is tested in diabetic mouse wounds in vivo, as we ultimately aim to develop a rapid and easy-to-use wound H₂O₂ assay to enable molecular diagnostics in DFU at the point-of-care.

Developing a liposomal hydrogel formulation with selective membrane permeability (high permeability for the analyte H₂O₂ and low permeability for the assay components HRP and S7) and high stability in the wound environment (varying pH values, proteins) coupled with a lyophilization procedure to prepare a dried formulation will be of high interest to the phospholipid community.

Benefit for the community

Phospholipid research community

The liposomal hydrogel formulation development will generate new knowledge about selectively permeable membranes, and the stability of liposomes in hydrogels and liposomal hydrogels in biological fluids (wound fluid). Developing a dried liposomal hydrogel formulation, we will provide cryo- and lyoprotectant-containing formulations and freeze-drying procedures with high cargo retention to the community. This information is of high interest regarding the scarcity of literature in lyophilized liposomal hydrogels. The generated knowledge will serve the emerging field of liposomal hydrogels in diagnostics, drug delivery, and biomedical and tissue engineering.

DFU patients

There is an unmet clinical care gap for molecular diagnostics in DFU.2) The H₂O₂-sensing wound dressing could enable molecular disease staging, the identification of patients with high wound H₂O₂ who will benefit most from H₂O₂-lowering treatment, and the assessment of treatment response on a molecular level, and thus enable personalized medicine in DFU.

Visit the supervisors lab

Prof. Dr. Simon Matoori (Université de Montréal)

Prof. Dr. Aristidis Veves (Beth Israel Deaconess Medical Center, a Harvard Medical School Teaching Hospital)