Antimicrobial photodynamic therapy in skin wound healing: A systematic review of animal studies

Abstract

Bacterial infection is a common wound complication that can significantly delay healing. Classical local therapies for infected wounds are expensive and are frequently ineffective. One alternative therapy is photodynamic therapy (PDT). We conducted a systematic review to clarify whether PDT is useful for bacteria‐infected wounds in animal models. PubMed and Medline were searched for articles on PDT in infected skin wounds in animals. The language was limited to English. Nineteen articles met the inclusion criteria. The overall study methodological quality was moderate, with a low‐moderate risk of bias. The animal models were mice and rats. The wounds were excisional, burn, and abrasion wounds. Wound size ranged from 6 mm in diameter to 1.5 × 1.5 cm2. Most studies inoculated the wounds with Pseudomonas aeruginosa or methicillin‐resistant Staphylococcus aureus. Eleven and 17 studies showed that the PDT of infected wounds significantly decreased wound size and bacterial counts, respectively. Six, four, and two studies examined the effect of PDT on infected wound‐cytokine levels, wound‐healing time, and body weight, respectively. Most indicated that PDT had beneficial effects on these variables. PDT accelerated bacteria‐infected wound healing in animals by promoting wound closure and killing bacteria.

Comparison of Antibacterial Activity and Wound Healing in a Superficial Abrasion Mouse Model of Staphylococcus aureus Skin Infection Using Photodynamic Therapy Based on Methylene Blue or Mupirocin or Both

“…Our clinical results agree with the already reported beneficial effect of aPDT on healing of S. aureus infected wounds in other models ( 34 , 49 , 72 , 73 , 77 ) and also in human patients ( 75 ). Furthermore, our clinical results add evidence about that MB-aPDT in particular improves the healing of different causal agent-infected skin wounds as previously was demonstrated by our group in sheep ( 74 ), recently in cattle ( 76 ) and it has been equally reported in humans ( 27 ).…”

Interplay of phosphate and carbonate ions with flavin photosensitizers in photodynamic inactivation of bacteria

“…A review article [ 60 ] listed 19 animal studies in which bacteria were treated in wounded skin using different PS. It is striking that the light exposure shows high values ranging from 6–423 J cm -2 with a mean value of 163 J cm -2 .…”

Treating Chronic Wounds Using Photoactive Metabolites: Data Mining the Chinese Pharmacopoeia for Potential Lead Species

“…A recently proposed strategy for identifying lead extracts and metabolites for novel topical treatments is the search for light-absorbing metabolites in species used traditionally in wound treatment, as we had detailed recently [10]. Medicinal plants combining antimicrobial and photoactivity could be reasonable candidates for photo-enhanced wound treatment, further developing photodynamic therapy (PDT) [11,12]. The screening of the CP [5] for plants used in TCM for wound treatment and displaying both antimicrobial and photodynamic activity seems a suitable novel strategy to identify species for potential clinical application of PDT.…”

“…Generally, the effects of PSs after light-activation may be clinically exploited for PDT, which has shown very promising outcomes in the treatment of wounds in animals and humans, including chronic conditions such as ulcers as well as for keratosis [11,12].…”

“…The exact mechanisms of action responsible for PDT-promoted wound healing are not completely clear yet. However, they have been reported to relate to the proliferation and activation of wound-associated fibroblasts and the induction of acute inflam-mation with subsequent recruitment of immune cells and secretion of growth factors that remove damaged cells and promote the healing process, respectively [11,12].…”