Photocatalysis and Photodynamic Therapy in Diabetic Foot Ulcers (DFUs) Care: A Novel Approach to Infection Control and Tissue Regeneration

Abstract

Photocatalysis and photodynamic therapy have been increasingly used in the management of diabetic foot ulcers (DFUs), and their integration into increasingly innovative treatment protocols enables effective infection control. Advanced techniques such as antibacterial photodynamic therapy (aPDT), liposomal photocatalytic carriers, nanoparticles, and nanomotors-used alone, in combination, or with the addition of antibiotics, lysozyme, or phage enzymes-offer promising solutions for wound treatment. These approaches are particularly effective even in the presence of comorbidities such as angiopathies, neuropathies, and immune system disorders, which are common among diabetic patients. Notably, the use of combination therapies holds great potential for addressing challenges within diabetic foot ulcers, including hypoxia, poor circulation, high glucose levels, increased oxidative stress, and rapid biofilm formation-factors that significantly hinder wound healing in diabetic patients. The integration of modern therapeutic strategies is essential for effective clinical practice, starting with halting infection progression, ensuring its effective eradication, and promoting proper tissue regeneration, especially considering that, according to the WHO, 830 million people worldwide suffer from diabetes.

Keywords: antibacterial photodynamic therapy; biofilm prevention; diabetic foot ulcers; diabetic wound; liposomes; nanoparticles; oxidative stress; photocatalysis; photosensitizer; tissue regeneration.

Figure 1

Pathophysiology of diabetic foot ulcers.

Figure 2

Fundamental benefits of photocatalysis in the treatment of diabetic foot ulcers (DFUs).

Figure 3

Summary of photocatalysis and photodynamic therapy methods in diabetic foot ulcer (DFU) care discussed in this review, along with a comparison of the key features of individual approaches.

Figure 4

Mechanism of action of antibacterial photodynamic therapy (aPDT).

Figure 5

Mechanism of action of a photo-driven H₂-releasing liposomal nanoplatform (Lip NP) composed of an upconversion nanoparticle (UCNP) linked to gold nanoparticles (AuNPs) through an ROS-sensitive connector and the usage of near-infrared (NIR) light laser.

Figure 6

Schematic illustration of the mechanism of action of hydrogen-incorporated titanium oxide nanorods in combination with visible light on skin cells.

Figure 7

The additive effect of combining antibiotic therapy with antimicrobial photodynamic therapy.

Figure 8

Comparison of useful methods for combating biofilm structure: nanomotors, novel nanoparticles, microneedles, micellar nanoparticles, along with a schematic representation of their mechanism of action.