Hematoporphyrin monomethyl ether-mediated photodynamic therapy inhibits the growth of keloid graft by promoting fibroblast apoptosis and reducing vessel formation

Advances in photodynamic therapy of pathologic scar

Pathologic scars include keloids and hypertrophic scars due to abnormal wound healing. Both cause symptoms of itching and pain; they also affect one's appearance and may even constrain movement. Such scars place a heavy burden on the individual's physical and mental health; moreover, treatment with surgery alone is highly likely to leave more scarring. Therefore, there is an urgent need for a treatment that is both minimally invasive and convenient. Photodynamic therapy (PDT) is an emerging safe and noninvasive technology wherein photosensitizers and specific light sources are used to treat malignant tumors and skin diseases. Research on PDT from both the laboratory and clinic has been reported. These findings on the treatment of pathologic scars using photosensitizers, light sources, and other mechanisms are reviewed in the present article.

Photodynamic therapy for male genital lichen sclerosus with urethral stricture-Case report

Male genital lichen sclerosus (MGLSc) typically impacts the external genitalia, resulting in balanitis, erectile pain, urination symptoms, and/or urinary retention. Urethral stricture develops in up to 20 % of these patients, which is usually found in the distal part of the urethra but can, in severe instances, impact the entire urethra and cause structural changes. Patients with skin lesions limited to the foreskin and partially extending to the glans can typically be cured by circumcision, but the recurrence rate of stricture is high when the glans or urethra is extensively involved. In the following case report, we describe a 45-year-old man with a history of MGLSc for 3 years and urethral stricture for 2 years, and these conditions remained untreated after circumcision. We emphasize that treatment with 5-aminolevulinic acid-induced photodynamic therapy (ALA-PDT) may further improve outcomes in such severe cases.

Polymyxin B-targeted liposomal photosensitizer cures MDR A. baumannii burn infections and accelerates wound healing via M1/M2 macrophage polarization

Multidrug-resistant (MDR) Acinetobacter baumannii infections pose a significant challenge in burn wound management, necessitating the development of innovative therapeutic strategies. In this work, we introduced a novel polymyxin B (PMB)-targeted liposomal photosensitizer, HMME@Lipo-PMB, for precise and potent antimicrobial photodynamic therapy (aPDT) against burn infections induced by MDR A. baumanni. HMME@Lipo-PMB-mediated aPDT exhibited enhanced antibacterial efficacy by specifically targeting and disrupting bacterial cell membranes, and generating increased intracellular ROS. Remarkably, even at low concentrations, this targeted approach significantly reduced bacterial viability in vitro and completely eradicated burn infections induced by MDR A. baumannii in vivo. Additionally, HMME@Lipo-PMB-mediated aPDT facilitated burn infection wound healing by modulating M1/M2 macrophage polarization. It also effectively promoted acute inflammation in the early stage, while attenuated chronic inflammation in the later stage of wound healing. This dynamic modulation promoted the formation of granulation tissue, angiogenesis, and collagen regeneration. These findings demonstrate the tremendous potential of HMME@Lipo-PMB-mediated aPDT as a promising alternative for the treatment of burn infections caused by MDR A. baumannii.

Progress in the clinical treatment of keloids

Keloid is a pathological scar that is higher than the skin surface following skin damage. Its lesion range often extends beyond the original damage boundary and does not naturally subside over time. Its pathogenesis is very complex, currently the main causes include fibroblast excessive proliferation, collagen and extracellular matrix (Extracellular matrix, ECM) excessive deposition, excessive angiogenesis, and so on. The traditional treatment method primarily involves surgical intervention, but it is associated with a high recurrence rate post-surgery. Consequently, many treatment methods are derived according to the different clinical characteristics of keloid. This paper will review the therapeutic progress in recent years from surgical treatment, physiotherapy, drug therapy, and biological therapy, with the goal of offering valuable insights for the clinical treatment of keloids.

A new photodynamic therapy photosensitizer (p1) promotes apoptosis of keloid fibroblasts by targeting caspase-8

Photodynamic therapy (PDT) is a new therapy for treating cancer with less toxicity, high selectivity, good cooperativity, and repetitive usability. However, keloid treatment by PDT is mainly focused on clinical appearance, and few studies have been conducted on the mechanisms of PDT. In this study, key factors of the classical mitochondrial apoptosis signaling pathway were measured to assess the effect of a new PDT photosensitizer (p1). A specific inhibitor of caspase-8 (Z-IETD-FMK) was also used to verify the possible mechanisms. Twelve samples were obtained from 12 patients (six with keloids and six without) selected randomly from the Department of Plastic Surgery at Peking Union Medical College Hospital from January to December 2020. After cell culture, fibroblasts were divided into 13 groups. The morphology of fibroblasts in each group was observed by microscopy. Cell activity was measured by cell counting kit-8, and cell apoptotic morphology was observed by TUNEL staining. The reactive oxygen species (ROS) relative value was measured by a ROS test kit. The expression levels of key mitochondrial factors (caspase-3, caspase-8, cytochrome-c, Bax, and Bcl-2) were assessed by western blot, and mRNA expression of caspase-3 and caspase-8 was measured by RT-qPCR. We showed that p1 had a satisfactory proapoptotic effect on keloid fibroblasts by increasing the expression of ROS, caspase-3, caspase-8, and cytochrome-c, and decreasing the Bcl-2/Bax ratio; however, this effect was partially inhibited by Z-IETD-FMK, indicating that caspase-8 may be one of the p1's targets to achieve the proapoptotic effect.

The Combination of the Mini-Punch Technique and Photodynamic Therapy for the Treatment of Mandibular Keloids and Hypertrophic Scars

BACKGROUND

Mandibular keloids and hypertrophic scars can exert significant effects on the appearance of a patient. However, current treatments are not effective in all cases. Consequently, it is vital to identify a safe and effective treatment method.

OBJECTIVE

To investigate the therapeutic effect of the mini-punch technique combined with photodynamic therapy (PDT) on mandibular keloids and hypertrophic scars.

PATIENTS AND METHODS

Twenty patients with mandibular keloids and hypertrophic scars were enrolled, including 5 cases of keloids and 15 cases of hypertrophic scars, with a total of 40 lesions. The mini-punch technique was performed first, and then, PDT was conducted, once a week on 3 occasions in total.

RESULTS

After 12 months of follow-up, 30 lesions had improved by more than 50%, thus achieving a good therapeutic effect. The Vancouver Scar Scale score of patients ranged between 8 and 12 points with a mean of 9.60 ± 1.09 points before surgery and between 2 and 9 points with a mean of 4.15 ± 2.05 points at 12 months after surgery. The mean Vancouver Scar Scale score after treatment was significantly lower than that before treatment (t = 11.80, p < .001).

CONCLUSION

A combination of the mini-punch technique and PDT is an effective treatment for mandibular keloids and hypertrophic scars.

Hemoporfin-Mediated Photodynamic Therapy for Port-Wine Stains: Multivariate Analysis of Clinical Efficacy and Optical Coherence Tomography Appearance

Background

Hemoporfin-mediated photodynamic therapy (HMME-PDT) is reported to be effective and safe for port-wine stains (PWS). However, its efficacy is influenced by several factors and there is no appropriate method to evaluate efficacy so far. Therefore, this study explored the clinical efficacy of HMME-PDT for PWS on the face and neck and the feasibility of evaluating treatment potency with optical coherence tomography (OCT).

Methods

A total of 211 PWS patients subjected to HMME-PDT were recruited for study and correlations of therapeutic effect with treatment sessions, age, gender, lesion distribution and treatment history analyzed. OCT was utilized for quantitative analysis of PWS lesions of 36 selected patients before and after HMME-PDT.

Results

The efficacy of two consecutive treatments was significantly higher than that of single treatment (P < 0.05). In multivariate analysis, after the first treatment, age, lesion distribution and treatment history were correlative factors affecting treatment efficacy (P < 0.05). The improvement effect on central facial lesions was lower than that on lateral facial lesions (P < 0.05). The efficacy of therapy on the group with no history of pulsed dye laser (PDL) treatment was greater than that on effective and ineffective treatment groups (P < 0.05). After the second session, age remained the only factor correlated with efficacy (P < 0.05). Dilated vessel diameter and depth before and after treatment were significantly different (P < 0.05). With increasing treatment times, age was the most significant factor influencing treatment efficacy.

Conclusions

Our collective findings indicate that HMME-PDT therapy is effective and safe for PWS and support the utility of OCT in objective assessment of the efficacy of HMME-PDT.

Successful treatment of facial hypertrophic scar with HMME-PDT: A case report

Treating hypertrophic scars is a challenge for clinicians. Herein, we report a case of one female with both a facial port wine stain and a hypertrophic scar treated with Hematoporphyrin monomethyl ether photodynamic therapy. Surprisingly, with the treatment of the facial port wine stain, the other skin lesion, the hypertrophic scar, also alleviated. HMME-PDT has been approved for application in PWS; however, this case showed effective easing of the hypertrophic scar lesion, which indicates that it might be a promising therapeutic method for hypertrophic scars.