Research Progress of Photodynamic Therapy in Wound Healing: A Literature Review

Photo-responsive self-expanding catheter with photosensitizer-integrated silicone-covered membrane for minimally invasive local therapy in malignant esophageal cancer

Photodynamic therapy (PDT) using photosensitizer (PS)-integrated covered self-expandable metallic stents (SEMS) is proposed a new therapeutic approach for the treatment of palliative malignancies; however, the currently hydrophobic PS reduces the photoreactive effect, which leads to aggregation with low water solubility. In here, an aluminum (III)-phthalocyanine chloride tetrasulfonic acid (Al-PcS4)-integrated silicone-covered self-expanding catheter was successfully fabricated to perform localized PDT. The ratio of MeOH and Al-PcS4 concentrations was optimized to achieve PS coating uniformity. The photodynamic activity of the Al-PcS4-integrated silicone membrane was evaluated through laser exposure on membrane-layered tumor cell lines, tumor xenograft-bearing mice. PDT with the Al-PcS4-integrated membrane successfully generated sufficient cytotoxic singlet oxygen, inducing cell death in the esophageal cancer cell lines. PDT-treated tumor xenograft-bearing mice undergo apoptotic cell death and showed significant tumor regression. Localized PDT using an Al-PcS4-integrated silicone-covered self-expanding catheter was technically successful in the rabbit esophagus without severe complications. Based on the endoscopy, esophagography, histology, and immunohistochemistry, our study verified that localized PDT using the Al-PcS4-integrated silicone-covered self-expanding catheter was effective and safe to evenly induce tissue damage. Al-PcS4-integrated silicone-covered self-expanding catheter has substantial potential for the minimally invasive local therapy in malignant esophageal cancer.

Participation of lipids in the tumor response to photodynamic therapy and its exploitation for therapeutic gain

Hydroperoxides of unsaturated membrane lipids (LOOHs) are the most abundant non-radical intermediates generated by photodynamic therapy (PDT) of soft tissues such as tumors and have far longer average lifetimes than singlet oxygen or oxygen radicals formed during initial photodynamic action. LOOH-initiated post-irradiation damage to remaining membrane lipids (chain peroxidation) or to membrane-associated proteins remains largely unrecognized. Such after-light processes could occur during clinical oncological PDT, but this is not well-perceived by practitioners of this therapy. In general, the pivotal influence of lipids in tumor responses to PDT needs to be better appreciated. Of related importance is the fact that most malignant tumors have dramatically different lipid metabolism compared with healthy tissues, and this too is often ignored. The response of tumors to PDT appears especially vulnerable to manipulations within the tumor lipid microenvironment. This can be exploited for therapeutic gain with PDT, as exemplified here by the combined treatment with the antitumor lipid edelfosine.

Hematoporphyrin photodynamic therapy for treatment of pathological scar with ulceration: A case report

Pathological scars result from abnormal wound healing and represent a fibrotic process in the repair of skin injuries. Post-burn scars are prone to malignant transformation, especially when ulceration occurs, raising concerns for precancerous lesions. We report a case of a 56-year-old female with a 50-year history of a large burn scar on her left forearm. The scar developed non-healing ulceration with local pain and itching over the past three years. Treatment with hematoporphyrin photodynamic therapy (HpD-PDT) led to resolution of the ulceration, thinning of the scar tissue, and significant alleviation of pain and itching. After a five-year follow-up, there has been no recurrence of ulceration, suggesting that photodynamic therapy effectively promotes wound healing in scarred tissue with ulcerations.

Efficacy of photodynamic therapy combined with cross-punch technique for the treatment of keloid

OBJECTIVE

Keloids are characterized by abnormal activation of fibroblasts and excessive collagen deposition. Keloids are notoriously difficult to treat effectively due to their high recurrence rate after therapy. Our study explored the use of the punch technique in conjunction with photodynamic therapy, a novel approach that may swiftly reduce keloid volume, promote collagen remodeling, mitigate inflammation and enhance the wound healing process.

METHODS

In our study, we conducted a retrospective analysis of 47 keloid patients who were treated with cross-punch technique combined with photodynamic therapy (punch+PDT group), compared them with a control group of 42 patients who received cross-punch therapy alone (punch group). The visual Analog Scale (VAS) scoring system, the Dermatology Life Quality Index (DLQI) questionnaire and the subjective scoring of patients were implemented to assess the improvement rate at baseline (month 0) and 12-month follow-up (month 12).

RESULTS

The results demonstrated significant enhancements in both VAS scores and DLQI scores on month 12 when compared with those on month 0. Notably, the subjective scoring indicated a marked difference, with 93.62 % of patients in the punch+PDT group and 59.52 % in the punch group reporting good or excellent improvement.

CONCLUSION

Patients in the punch+PDT group had a significant improvement rate than those in the punch group.

Photodynamic Therapy Healing a Refractory Radiation-Induced Ulcer on the Chest Wall Postmastectomy Radiotherapy for Breast Cancer: A Case Report and Literature Overview

Photodynamic therapy (PDT) has been used to treat cancers. It has also been used to treat infectious diseases and inflammatory conditions. PDT promotes wound healing, while clinical use of PDT for wound healing is uncommon and not thoroughly investigated. We report a 75-year-old female with a radiation-induced non-healing ulcer for five years on the chest wall postmastectomy radiotherapy. Biopsy showed epidermal erosion with dermal inflammation but no recurrent cancer. She was referred from the wound care clinic after multiple unsuccessful attempts to manage wound healing for two years involving daily home nursing visits. PDT was discussed with the patient who consented to PDT instead of hyperbaric oxygen therapy (HBOT) for fear of its side effects. Her wound improved after a total of three treatments and the process of wound healing continued for 14 months since her first treatment session. The presented case supports the beneficial effects of PDT on chronic ulceration impeding healing of a postmastectomy radiotherapy wound. To our knowledge, this report is unique in documenting details of PDT healing a chronic refractory ulcer of five years, which developed after cancer therapy (mastectomy and radiotherapy). Further clinical study of PDT is needed on wound healing post-surgery and radiation in cancer patients. An overview of HBOT in comparison with PDT for wound healing is presented.

Increased CD56 expression after photodynamic therapy indicates an increased natural killer cell count following early photodynamic therapy for cutaneous squamous cell carcinoma

Cutaneous squamous cell carcinoma (cSCC) is the second most common type of skin cancer. Photodynamic therapy (PDT) is a promising therapeutic method for managing cSCC due to its proven ability to target specific areas over time and its low risk of side effects. PDT may cause tissue damage and vascular shutdown, and may regulate local immunological responses. The present study aimed to investigate and compare the early lymphocyte modifications before and after PDT for SCC. A total of 10 patients with SCC were identified by pathological investigation. Initially, all wounds were treated with 20% aminolevulinic acid (ALA)-PDT as the initial stage in the therapeutic procedure. The wounds were treated by exposing them to red LED light with a wavelength of 635 nm, an energy density of 100 J/cm2 and an intensity of 80 mW/cm2. The tumor tissue was surgically removed 24 h later, and another round of PDT therapy was administered. Immunohistochemistry for CD3 and CD56 was conducted on the wound tissue post-surgery. If the wound showed granulation, necrosis or secretion, debridement was added to the therapy. All patients were monitored for 0.6-1.0 year post-treatment. ALA-PDT combination surgery fully controlled the tumor tissue in all 10 patients. The immunohistochemical analysis of the wound tissues showed that the expression of CD56 increased, while the expression of CD3 was not different after photodynamic therapy. These results also indirectly indicated that the overall count of NK cells in the 10 patients increased, nevertheless, there was no alteration in the T lymphocyte count. In conclusion, the ALA-PDT combination surgical therapy for cSCC demonstrates favorable results. An increase in CD56 expression may be a mechanism for the effective treatment of cSCC with PDT.

Pharmacotherapy for Keloids and Hypertrophic Scars

Keloids (KD) and hypertrophic scars (HTS), which are quite raised and pigmented and have increased vascularization and cellularity, are formed due to the impaired healing process of cutaneous injuries in some individuals having family history and genetic factors. These scars decrease the quality of life (QOL) of patients greatly, due to the pain, itching, contracture, cosmetic problems, and so on, depending on the location of the scars. Treatment/prevention that will satisfy patients' QOL is still under development. In this article, we review pharmacotherapy for treating KD and HTS, including the prevention of postsurgical recurrence (especially KD). Pharmacotherapy involves monotherapy using a single drug and combination pharmacotherapy using multiple drugs, where drugs are administered orally, topically and/or through intralesional injection. In addition, pharmacotherapy for KD/HTS is sometimes combined with surgical excision and/or with physical therapy such as cryotherapy, laser therapy, radiotherapy including brachytherapy, and silicone gel/sheeting. The results regarding the clinical effectiveness of each mono-pharmacotherapy for KD/HTS are not always consistent but rather scattered among researchers. Multimodal combination pharmacotherapy that targets multiple sites simultaneously is more effective than mono-pharmacotherapy. The literature was searched using PubMed, Google Scholar, and Online search engines.

Anti-adhesion multifunctional poly(lactic-co-glycolic acid)/polydimethylsiloxane wound dressing for bacterial infection monitoring and photodynamic antimicrobial therapy

Wound infection and adhesion are important factors affecting wound healing. Early detection of pathogen infection and reduction of wound-to-dressing adhesion are critical for improving wound healing. Herein, Ester-J, which can rapidly respond to lipase secreted by bacteria, was designed and synthesized. Then, Ester-J was co-spun with poly(lactic-co-glycolic acid) (PLGA) and polydimethylsiloxane (PDMS) to prepare a PP-EsJ hydrophobic anti-adhesion dressing with a contact angle of 140.7°. When the PP-EsJ membrane came into contact with the bacteria, the loaded Ester-J was hydrolyzed to Tph-TSF-OH, releasing bright cyan-blue fluorescence, thus providing a fluorescence switch for an early warning of infection. The detection limits of PP-EsJ for Pseudomonas aeruginosa and Staphylococcus aureus were 1.0 × 105 and 1.0 × 106 CFU/mL, respectively. Subsequently, Tph-TSF-OH released 1O2 through light irradiation, which rapidly killed P. aeruginosa and S. aureus, and accelerated wound healing. Compared with the control group, enhanced wound closure (up to 99.80 ± 1.10 %) was observed in mice treated with the PP-EsJ membrane. The PP-EsJ membrane not only effectively reduced the risk of external infection but also reduced adhesions to the skin during dressing changes. These characteristics make PP-EsJ membranes potentially useful for clinical treatment.

The Use of Photoactive Polymeric Nanoparticles and Nanofibers to Generate a Photodynamic-Mediated Antimicrobial Effect, with a Special Emphasis on Chronic Wounds

This review is concerned with chronic wounds, with an emphasis on biofilm and its complicated management process. The basics of antimicrobial photodynamic therapy (PDT) and its underlying mechanisms for microbial eradication are presented. Intrinsically active nanocarriers (polydopamine NPs, chitosan NPs, and polymeric micelles) that can further potentiate the antimicrobial photodynamic effect are discussed. This review also delves into the role of photoactive electrospun nanofibers, either in their eluting or non-eluting mode of action, in microbial eradication and accelerating the healing of wounds. Synergic strategies to augment the PDT-mediated effect of photoactive nanofibers are reviewed.

Photodynamic Therapy Supported by Antitumor Lipids

Photodynamic therapy (PDT) destroys tumors by generating cytotoxic oxidants that induce oxidative stress in targeted cancer cells. Antitumor lipids developed for cancer therapy act also by inflicting similar stress. The present study investigated whether tumor response to PDT can be improved by adjuvant treatment with such lipids using the prototype molecule edelfosine. Cellular stress intensity following Photofrin-based PDT, edelfosine treatment, or their combination was assessed by the expression of heat shock protein 70 (HSP70) on the surface of treated SCCVII tumor cells by FITC-conjugated anti-HSP70 antibody staining and flow cytometry. Surface HSP70 levels that became elevated after either PDT or edelfosine rose much higher after their combined treatment. The impact of Photofrin-PDT-plus-edelfosine treatment was studied with three types of tumor models grown in syngeneic mice. With both SCCVII squamous cell carcinomas and MCA205 fibrosarcoma, the greatest impact was with edelfosine peritumoral injection at 24 h after PDT, which substantially improved tumor cure rates. With Lewis lung carcinomas, edelfosine was highly effective in elevating PDT-mediated tumor cure rates even when injected peritumorally immediately after PDT. Edelfosine used before PDT was ineffective as adjuvant with all tumor models. The study findings provide proof-in-principle for use of cancer lipids with tumor PDT.