The application of physical pretreatment in photodynamic therapy for skin diseases

Photodynamic Therapy as a Novel Therapeutic Modality Applying Quinizarin-Loaded Nanocapsules and 3D Bioprinting Skin Permeation for Inflammation Treatment

Skin inflammation associated with chronic diseases involves a direct role of keratinocytes in its immunopathogenesis, triggering a cascade of immune responses. Despite this, highly targeted treatments remain elusive, highlighting the need for more specific therapeutic strategies. In this study, nanocapsules containing quinizarin (QZ/NC) were developed and evaluated in an in vitro model of keratinocyte-mediated inflammation, incorporating the action of photodynamic therapy (PDT) and analyzing permeation in a 3D skin model. Comprehensive physicochemical, stability, cytotoxicity, and permeation analyses of the nanomaterials were conducted. The nanocapsules demonstrated desirable physicochemical properties, remained stable throughout the analysis period, and exhibited no spectroscopic alterations. Cytotoxicity tests revealed no toxicity at the lowest concentrations of QZ/NC. Permeation and cellular uptake studies confirmed QZ/NC permeation in 3D skin models, along with intracellular incorporation and internalization of the drug, thereby enhancing its efficacy in drug delivery. The developed model for inducing the inflammatory process in vitro yielded promising results, particularly when the synthesized nanomaterial was combined with PDT, showing a reduction in cytokine levels. These findings suggest a potential new therapeutic approach for treating inflammatory skin diseases.

Fire needle pretreatment with 5-aminolevulinic acid photodynamic therapy combined with low-dose isotretinoin in the treatment of severe refractory nodulocystic acne

BACKGROUND

Nodulocystic acne is a severe form of acne, which is commonly treated with oral isotretinoin, hormones, or antibiotics. However, drug therapy often has some side effects and poor compliance. Fire needle combined with 5-aminolevulinic acid photodynamic therapy (ALA-PDT) is a simple, effective, short-term treatment with few adverse reactions, which is expected to be an effective physiotherapy for nodulocystic acne. Moreover, the combination with isotretinoin can reduce the dosage of the drug, thereby reducing the side effects of isotretinoin.

OBJECTIVES

To evaluate the safety and efficacy of fire-needle pretreated ALA-PDT combined with low-dose isotretinoin in the treatment of severe refractory nodulocystic acne.

METHODS

This study reported 10 patients with refractory nodulocystic acne who received combined treatment. During the treatment period, all patients received a low dose of oral isotretinoin capsules daily. The acne lesions were pretreated with fire needle before ALA-PDT treatment. The number of acne lesions, including papules, pustules, and nodular cysts, was documented at weeks 0, 2, 4, 8, and 12 to assess the therapeutic efficacy. Concurrently, adverse reactions such as pain, pruritus, and pigmentation changes were recorded and evaluated throughout the treatment course.

RESULTS

After combined treatment, all patients achieved good therapeutic effects, with an overall effective rate of 90 % at week 12. After treatment, skin lesions such as nodules, and cysts subsided significantly. The combination therapy has no serious adverse effects and has a favorable safety profile.

CONCLUSION

Fire needle pretreatment ALA-PDT combined with low-dose isotretinoin is effective and safe in the treatment of severe refractory nodular cystic acne, which is worthy of clinical promotion and research.

Efficacy and safety of fractional carbon dioxide laser followed by 5-aminolevulinic acid photodynamic therapy for keloids

BACKGROUND

Keloids are aggressive fibroproliferative disorders that cause aesthetic and functional damage. Photodynamic therapy (PDT) has shown promise as a novel treatment for keloids. However, the limited penetration of 5-aminolevulinic acid (ALA) and unsatisfactory outcomes in dense scars hinder its effectiveness as a monotherapy. The objective of this study is to assess the efficacy and safety of fractional CO2 laser followed by 5-ALA PDT for keloids.

METHODS

A total of 12 patients with keloid were included in our study. Each lesion was pretreated by fractional CO2 laser with 26-28 W to create microthermal zones. After topical application of 5-ALA solution, an irradiation of 635 nm red light with 120 J/cm2 was performed. The treatment was repeated at least every 2 weeks. Efficacy and safety were evaluated using the Vancouver Scar Scale (VSS), the Visual Analogue Scale (VAS) for keloid-related symptoms and documentation of postoperative complications. Statistical analysis was performed to compare VSS and keloid-related symptom VAS scores of the baseline and final treatment sessions.

RESULTS

The final treatment resulted in a statistically significant decrease in all parameters of VSS and VAS for pruritus and pain compared to the baseline. Except for postoperative hyperpigmentation, no infections, scar aggravation, or recurrence were observed during at least 6 months of follow-up. Overall, patients expressed a high level of satisfaction with the treatment outcome.

CONCLUSIONS

Fractional CO2 laser followed by 5-ALA PDT is a promising method for treating keloids. However, its synergetic effects need to be validated through clinical trials involving larger patient cohorts.

Assessment of therapeutic efficacy in seven cases of basal cell carcinoma in the ear and nose region treated with new surgical excision and immediate photodynamic therapy

BACKGROUND

Basal cell carcinoma (BCC) is the most prevalent non-melanoma skin tumor. It commonly affects exposed areas. Currently, surgical resection is considered the primary approach for BCC treatment. However, BCC frequently affects exposed facial areas, leading to visible scars after surgery. PDT has garnered increasing recent attention, demonstrating superior efficacy and favorable cosmetic outcomes for superficial BCCs. However, it shows limited treatment effectiveness for deep-seated tumors. Most of the current literature focuses on the combination of surgery and postoperative PDT, while no studies have reported on the use of standard surgical excision with intraoperative margin pathological monitoring and immediate PDT. Therefore, we implemented a treatment protocol combining surgery and immediate PDT. Accordingly, this paper aimed to explore the effectiveness, cosmetic outcomes, and other relevant advantages of this therapeutic approach.

METHODS

We aimed to evaluate this approach in seven patients with BCC on the nose and ears. Standard surgical excision of skin lesions was performed, with intraoperative frozen section examination of the margins, followed by immediate postoperative PDT for the wounds, and continued periodic PDT during the second phase of wound healing.

RESULTS

All seven cases demonstrated significant improvement. The cosmetic rating was 100 % and no cases of recurrence existed among the seven patients.

CONCLUSIONS

This approach effectively minimized the surgical wound, improved tumor clearance, achieved precise therapeutic effects, and reduced the recurrence rate. Moreover, it produced favorable cosmetic outcomes.

Efficacy and safety of microneedling, fractional CO2 laser, and cryotherapy combined with 5-aminolevulinic acid photodynamic therapy in the treatment of actinic keratosis: A multicenter prospective randomized controlled study

BACKGROUND

Photodynamic therapy (PDT) for actinic keratosis (AK) is limited by the depth of treatment. Microneedling or fractional CO2 laser can facilitate the penetration of photosensitizer, while cryotherapy can treat deeper tissues but is not suitable for field cancerization.

OBJECTIVE

To investigate the efficacy of microneedling, fractional CO2 laser, and cryotherapy in combination with PDT for AK.

METHODS

Patients with AK were randomized into 4 groups, including group A with microneedling + PDT, group B with fractional CO2 laser + PDT, group C with cryotherapy + PDT, and group D with PDT. After 12 weeks, the clinical, dermoscopic, and reflectance confocal microscopy (RCM) outcomes were assessed.

RESULTS

A total of 129 patients were included in this study, with 31, 30, 35, and 31 patients in each group, yielding clinical response rates of 90.3%, 93.3%, 97.1%, and 74.2%, respectively (P=0.026). The RCM response rates were 71.0%, 80.0%, 85.7%, and 54.8%, respectively (P=0.030). The dermoscopic response rates were 77.4%, 83.3%, 88.6%, and 60.0%, respectively (P=0.039). Group C showed the best efficacy in terms of clinical, dermoscopic, and RCM outcomes.

CONCLUSIONS

All three treatments improved the efficacy of PDT and were well tolerated, with cryotherapy + PDT showing the best efficacy.

Improving the efficacy of photodynamic therapy for actinic keratosis: A comprehensive review of pharmacological pretreatment strategies

BACKGROUND

Photodynamic therapy (PDT) is approved for treatment of actinic keratoses (AKs) and field-cancerisation. Pretreatment with pharmacological compounds holds potential to improve PDT efficacy, through direct interaction with PpIX formation or through an independent response, both of which may improve PDT treatment.

OBJECTIVE

To present the currently available clinical evidence of pharmacological pretreatments prior to PDT and to associate potential clinical benefits with the pharmacological mechanisms of action of the individual compounds.

METHODS

A comprehensive search on the Embase, MEDLINE, and Web of Science databases was performed.

RESULTS

In total, 16 studies investigated 6 pretreatment compounds: 5-fluorouracil (5-FU), diclofenac, retinoids, salicylic acid, urea, and vitamin D. Two of these, 5-FU and vitamin D, robustly increased the efficacy of PDT across multiple studies, illustrated by mean increases in clearance rates of 21.88% and 12.4%, respectively. Regarding their mechanisms, 5-FU and vitamin D both increased PpIX accumulation, while 5-FU also induced a separate anticarcinogenic response. Pretreatment with diclofenac for four weeks improved the clearance rate in one study (24.9%), administration of retinoids had a significant effect in one of two studies (16.25%), while salicylic acid and urea did not lead to improved PDT efficacy. Diclofenac and retinoids demonstrated independent cytotoxic responses, whereas salicylic acid and urea acted as penetration enhancers to increase PpIX formation.

CONCLUSION

5-FU and vitamin D are well-tested, promising candidates for pharmacological pretreatment prior to PDT. Both compounds affect the haem biosynthesis, providing a target for potential pretreatment candidates.

KEY WORDS

Photodynamic Therapy, Actinic Keratosis,Pre-tretment,Review,enhancement.

Light-related activities of metal-based nanoparticles and their implications on dermatological treatment

Metal-based nanoparticles (MNPs) represent an emerging class of materials that have attracted enormous attention in many fields. By comparison with other biomaterials, MNPs own unique optical properties which make them a potential alternative to conventional therapeutic agents in medical applications. Especially, owing to the easy access to the skin, the use of MNPs based on their optical properties has gained importance for the treatment of a variety of skin diseases. This review provides an insight into the different optical properties of MNPs, including photoprotection, photocatalysis, and photothermal, and highlights their implications in treating skin disorders, with a special emphasis on their use in infection control. Finally, a perspective on the safety concern of MNPs for dermatological use is discussed and analyzed. The information gathered and presented in this review will help the readers have a comprehensive understanding of utilizing the photo-triggered activity of MNPs for the treatment of skin diseases.

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.

Sandpaper curettage: A simple method to improve PDT outcomes for actinic keratosis

INTRODUCTION

Photodynamic therapy (PDT) is a non-scarring, repeatable, and safe treatment for actinic keratosis (AK), but improvements in efficacy are still needed.

BACKGROUND

Devices such as steel blades, needle rollers, and lasers are currently used to remove hypertrophic stratum corneum on AKs to improve PDT outcomes. However, curettage with fine sandpaper could be a gentler, effective alternative.

METHODS

A retrospective study was designed to compare PDT with or without sandpaper curettage. Patients were selected from a database registry of patients with face and scalp AKs (ClinicalTrials.gov NCT03319251). Patients in Group 1 underwent PDT alone (20% ALA, 15 min; blue light 417 nm, 30 min). Patients in Group 2 were pretreated with gentle sandpaper curettage prior to ALA and illumination. The two groups were compared using multivariate matching, normalizing for age, sex, initial AK counts, and time to follow-up.

RESULTS

Sixty-six patients were selected for matching analysis (n=38, PDT only; n=28, PDT+curettage). Demographics between the groups were similar (mean ± SD), including age (71.0 ± 8.3 vs. 71.0 ± 8.0 years), baseline AK count (53 ± 39 vs. 44± 32), and time to post-PDT follow-up (111 ± 28 vs. 113 ± 32 days). At follow-up, patients who received curettage showed an overall 55% improvement in scalp AK clearance compared to patients who did not receive curettage, adjusting for sex, age, time to follow-up, and baseline AK count (p = 0.0322, multivariable linear regression).

DISCUSSION

Sandpaper curettage before PDT treatment is an easy and inexpensive method to significantly improve AK clearance rates.

A Combined Cyanine/Carbomer Gel Enhanced Photodynamic Antimicrobial Activity and Wound Healing

As a non-invasive and non-specific therapeutic approach, photodynamic therapy (PDT) has been used to treat antibiotic-resistant bacteria with encouraging efficacy. Inspired by light, the photosensitizers can produce excessive reactive oxygen species (ROS) and, thus, effectively destroy or kill bacteria. Cyanine (Cy), a traditional photosensitizer for PDT, has the advantages of low cytotoxicity and high ROS yield. Yet, the water solubility and photostability for Cy are poor, which substantially limit its antibacterial efficiency and clinical translation. Herein, we combined Cy with carbomer gel (CBMG) to form a photodynamic Cy-CBMG hydrogel. In this system, Cy was evenly dispersed in CBMG, and CBMG significantly improved the water solubility and photostability of Cy via electrostatic interactions. The developed Cy-CBMG gel had less photodegradation under laser irradiation and thus can effectively elevate ROS accumulation in bacteria. The Cy-CBMG compound presented remarkable ROS-induced killing efficacy against methicillin-resistant Staphylococcus aureus (93.0%) and extended-spectrum β-lactamase-producing Escherichia coli (88.7%) in vitro. Moreover, as a potential wound dressing material, the Cy-CBMG hydrogel exhibited excellent biocompatibility and effective antimicrobial ability to promote wound healing in vivo. Overall, this work proposed a practical strategy to synthesize a photosensitizer–excipient compound to enhance the photophysical property and antibacterial efficacy for PDT.

The Efficacy of Topical Photodynamic Therapy in Precancerous Lesions of the Skin: A Literature Review

Precancerous skin lesions are associated with high probability of malignant transformation to squamous cell carcinoma. Early detection and management are necessary to improve prognosis and outcomes. Literatures showed that topical photodynamic therapy (PDT) is a promising treatment method which can be successfully applied in several conditions in dermatology. This study aims to review the efficacy of topical PDT for various precancerous lesions in dermatology, such as actinic keratosis, Bowen disease, and Bowenoid papulosis.

Dermabrasion combined with photodynamic therapy: a new option for the treatment of non-melanoma skin cancer

Non-melanoma skin cancer (NMSC) is the most common malignancy. Photodynamic therapy (PDT) is effective for the treatment of certain NMSCs. However, the clinical response rates of some NMSCs to single PDT are still far from ideal. The reason may be that PDT has shown limited efficacy in managing thicker NMSCs. To explore the efficacy and safety of dermabrasion combined with PDT (D-PDT) for the treatment of NMSCs. This was a retrospective, single-arm, multi-centre study. In total, 172 tumours from 40 patients were treated with D-PDT during the study period. The mean follow-up period was 40 months (range 15-110 months). D-PDT was performed with 633-nm red light at 80 m W/cm² after lesion dermabrasion and 4 h of photosensitizer exposure. Six nodular basal cell carcinomas (nBCCs) from 6 patients, 9 squamous cell carcinomas (SCCs) from 9 patients, 17 Bowen diseases (BDs) from 10 patients and 140 actinic keratoses (AKs) from 15 patients treated with D-PDT were examined in this study. Only two patients with three AKs experienced recurrence over 12 months. The mean final follow-up periods of patients with AKs, BDs, nBCCs and SCCs were 30, 33, 45 and 60 months, respectively. Thirty-four of the 40 patients treated with D-PDT reported excellent or good cosmetic results. The mean Dermatology Life Quality Index (DLQI) scores of the patients improved significantly after treatment (estimated MD 9.72 [95% CI 8.69 to 10.75]; p < 0.001). D-PDT is a safe, cosmetic and effective treatment that could be a new candidate therapeutic for NMSC.