Comparison of efficacy, adverse effects and costs between 20 % ALA-PDT and 10 % ALA-PDT for the treatment of actinic keratosis in Chinese patients

Two-step photodynamic therapy for facial acne: a randomized controlled trial of pain reduction with 630 nm red light laser

Although topical 5-aminolevulinic acid photodynamic therapy (5-ALA PDT) is an effective treatment for facial acne, many patients report significant pain during the irradiation phase, compromising adherence. Two-step PDT, which modifies irradiance in two phases, has been proposed to reduce pain without compromising treatment efficacy. In this single-center, assessor-blinded randomized trial, 26 patients with facial acne were allocated to either a two-step PDT group (n = 12) or a conventional PDT group (n = 14). After applying 20% 5-ALA for 2 h, both groups received red light (630 ± 5 nm) to deliver a total fluence of 120 J/cm2. In the two-step group, treatment began at 40 mW/cm2 for 5 min, then increased to 100 mW/cm2 for 18 min. In the conventional group, irradiance was set at 100 mW/cm2 for 20 min. Pain was measured using the Numerical Rating Scale (NRS) at 6, 12, 18, 24, and 30 min after initiation of irradiation. Clinical efficacy, adverse events, recurrence, and patient satisfaction were also evaluated. All 26 patients completed three PDT sessions. Pain scores were significantly lower in the two-step group at every time point (p < 0.05). Both groups had comparable clinical efficacy, recurrence rates, and satisfaction levels (p > 0.05). Adverse events were less frequent in the two-step group but did not differ statistically from the conventional group. Two-step PDT using 5-ALA and 630 nm red light laser substantially reduces pain during acne treatment while maintaining equivalent clinical efficacy, recurrence rates, and patient satisfaction. This modified protocol may improve patient tolerance and adherence to PDT.

Engineered production of 5-aminolevulinic acid in recombinant Escherichia coli BL21

5-aminolevulinic acid (ALA) is a non-protein amino acid that has been widely used in the fields of medicine and agriculture. This study aims to engineer the C5 pathway of the ALA biosynthesis in Escherichia coli BL21 to enhance ALA production. The ALA synthase genes gltX, hemA, and hemL were overexpressed in E. coli BL21 to lead to the increase in the production of ALA. The sRNA RyhB was also overexpressed to downregulate the expression of ALA dehydratase to reduce the downstream bioconversion of ALA to porphobilinogen. Next, the gene arcA was knocked out by CRISPR-Cas9 technology to open the TCA cycle to promote the respiratory metabolism of the strain to reduce the feedback inhibition of heme to ALA. The fermentation conditions of the engineered strain were optimized by response surface experiments. The time-course analysis of the ALA production was carried out in a 1 L shake flask. Through these efforts, the production of ALA in engineered strain reached 2953 mg/L in a 1 L shake flask. This study contributes to the industrial production of ALA by the engineered E. coli in the future.

Efficacy of 5-aminolevulinic acid photodynamic therapy for Olsen Grade 3 actinic keratosis: A prospective cohort study

BACKGROUND

Actinic keratosis (AK) is a common cutaneous keratinocyte dysplasia categorized by the Olsen Grade (OG) 1-3. OG 3 AK, which has a higher risk of progressing to cutaneous squamous cell carcinoma (cSCC), presents treatment challenges. While 5-aminolevulinic acid photodynamic therapy (ALA-PDT) is effective for non-hyperkeratotic AK (OG 1-2), its efficacy for OG 3 AK remains debated.

METHODS

To evaluate the efficacy and safety of ALA-PDT for the treatment of OG 3 AK, this single-center prospective cohort study included 127 patients with histopathologically confirmed AK, grouped by the Olsen grading (OG 3, n = 33; OG 1 or 2, n = 94). All patients received four sessions of ALA-PDT and were followed up for 12 months. The primary outcome was initial complete clearance (CC) at 3 months, while sustained CC at 12 months was the secondary outcome. Safety was assessed throughout the study.

RESULTS

The initial CC rates were 87.88 % (29/33) for the OG 3 group and 92.55 % (87/94) for the OG 1/2 group. The sustained CC rates at 12 months were 89.66 % (26/29) and 86.21 % (75/87) for the OG 3 and OG 1/2 groups, respectively. No significant difference was observed between the two groups for either initial CC or sustained CC rates (p > 0.05). Adverse events were mostly mild and transient, though long-lasting erythema at 12 months was more common in the OG 3 group compared with the OG 1/2 group (23.08 % vs. 5.33 %, p = 0.01).

CONCLUSION

ALA-PDT demonstrates favorable efficacy and safety profile for OG 3 AK, supporting ALA-PDT as a valuable non-invasive treatment option for OG 3 AK.

Tea polyphenols nanoparticles integrated with microneedles multifunctionally boost 5-aminolevulinic acid photodynamic therapy for skin cancer

5-aminolevulinic acid photodynamic therapy (ALA-PDT) is an emerging therapeutic strategy for skin cancer due to its noninvasiveness and high spatiotemporal selectivity. However, poor skin penetration, poor intratumoral delivery, the instability of aqueous ALA, and the tumor's inherent hypoxia microenvironment are major hurdles hindering the efficacy of ALA-PDT. Herein, we aim to address these challenges by using microneedles (MNs) to assist in delivering nanoparticles based on natural polymeric tea polyphenols (TP NPs) to self-assemble and load ALA (ALA@TP NPs). The TP NPs specifically increase cellular uptake of ALA by A375 and A431 cells and reduce mitochondrial membrane potential. Subsequently, the photosensitizer protoporphyrin IX derived from ALA accumulates in the tumor cells in a dose-dependent manner with TP NPs, generating reactive oxygen species to promote apoptosis and necrosis of A375 and A431 cells. Interestingly, TP NPs can ameliorate the tumor's inherent hypoxia microenvironment and rapid oxygen consumption during PDT by inhibiting hypoxia inducible factor-1α, thereby boosting reactive oxygen species (ROS) generation and enhancing ALA-PDT efficacy through a positive feedback loop. After ALA@TP NPs are loaded into MNs to fabricate ALA@TP NPs@MNs, the MNs enhance skin penetration and storage stability of ALA. Importantly, they exhibit remarkable antitumor efficacy in A375-induced melanoma and A431-induced squamous cell carcinoma with a reduced dose of ALA and reverse hypoxia in vivo. This study provides a facile and novel strategy that integrates MNs and green NPs of TP for addressing the bottlenecks of ALA-PDT and enhancing the ALA-PDT efficacy against skin cancers for future clinical translation.

Field Cancerization Therapies for the Management of Actinic Keratosis: An Updated Review

Field cancerization theory highlights that the skin surrounding actinic keratoses (AK) is also at increased risk for possible malignant transformation; thus, field-directed treatments may both reduce the risk of AK recurrence and potentially reduce the risk of development of cutaneous squamous cell carcinoma (cSCC). Photodynamic therapy (PDT) with either aminolevulinic acid (ALA) or methylaminolevulinate (MAL), as well as topical treatments such as 5-fluorouracil (5-FU), diclofenac gel, piroxicam, imiquimod, and ingenol mebutate, have all shown higher efficacy than vehicle treatments. PDT is widely recognized for its high efficacy; however, concerns for associated pain have driven new studies to begin using alternative illumination and pretreatment techniques, including lasers. Among topical treatments, a combination of 5-FU and salicylic acid (5-FU-SA) has shown to be the most effective but also causes the most adverse reactions. Tirbanibulin, a new topical agent approved for use in 2020, boasts a favorable safety profile in comparison with imiquimod, 5-FU, and diclofenac. Meanwhile, ingenol mebutate is no longer recommended for the treatment of AKs due to concerns for increased risk of cSCC development. Moving forward, an increasing number of studies push for standardization of outcome measures to better predict risk of future cSCC and use of more effective measures of cost to better guide patients. Here, we present an updated and comprehensive narrative review both confirming the efficacy of previously mentioned therapies as well as highlighting new approaches to PDT and discussing the use of lasers and novel topical treatments for treatment of AK.

Limitations of ALA-PDT as a reliable therapy for AK in clinical practice

BACKGROUND

Numerous clinical studies have demonstrated the effectiveness of 5-aminolevulinic acid (ALA)-mediated photodynamic therapy (PDT) in treating actinic keratosis (AK). This therapy has achieved an average lesion clearance rate of approximately 80 % and has also shown to produce satisfactory cosmetic outcomes. However, in our clinical practice, the utilization and adherence to ALA-PDT treatment among AK patients has been lower than anticipated, possibly due to various factors.

OBJECTIVE

The objectives of this study are twofold: (1) To analyze the actual therapeutic effects of ALA-PDT treatment on AK lesions in clinical practice; and (2) To identify the factors that hinder acceptance of ALA-PDT therapy among AK patients with large area or multiple lesions situated on the head and face.

METHOD

This study included a group of 20 AK patients, comprising 15 females and 5 males, with an age range of 57-87 years. All patients received a complete course of ALA-PDT therapy, consisting of 3-6 treatments. The study analyzed various factors, including the cure rate, recurrence rate, cosmetic effects, and adverse reactions following treatment. To investigate the factors affecting the acceptance of ALA-PDT treatment among AK patients with large or multiple lesions on the head and face, we also examined a separate group of 43 AK patients. This group included individuals who either had incomplete courses of ALA-PDT treatment or declined the therapy for the first time. The factors potentially influencing patients' acceptance of PDT were analyzed based on the outcomes of these investigations.

RESULT

Among the 20 patients who completed the full course of ALA-PDT treatment, the cure rate was 95 % (19/20). The recurrence rates at 1 month, 3 months, and 6 months were 0 %, 5 %, and 10 %, respectively. Out of the 19 cured patients, only 2 experienced heavy pigmentation, and no scarring was reported 1-3 months post-treatment. Based on the survey of 43 patients who either had an incomplete course of ALA-PDT treatment or declined the therapy initially, several factors were identified as limiting their choice of PDT therapy. These factors include: (1) Intolerable adverse effects of treatment. (2) Higher treatment cost than expected. (3) Inconvenient transportation. (4) Coexistence of other senile diseases. (5) Unsatisfactory clinical efficacy observed. (6) Inadequate understanding of AK. (7) Lost to follow-up.

CONCLUSION

The study concludes that ALA-PDT is a beneficial and aesthetically pleasing treatment for AK patients, particularly those with extensive or multiple lesions on the head and face. However, various factors can impede the selection of ALA-PDT therapy, potentially depriving patients of the most suitable option. The study aims to assist dermatologists and AK patients in considering treatment plans and exploring alternative options. Overall, the findings of this study may provide valuable guidance for improving treatment outcomes and patient satisfaction.

Positive effects of low-dose photodynamic therapy with aminolevulinic acid or its methyl ester in skin rejuvenation and wound healing: An update

In dermatology, photodynamic therapy (PDT) is widely used in skin tumors, infections, etc., because of the killing effect triggered by toxic reactive oxygen species (ROS). However, the ROS concentration is determined by various photosensitizer concentrations and formulations, as well as various irradiation parameters. Low-dose PDT leads to sufficiently low ROS level, which results in biological effects that are the exact opposite of the killing potency. Therefore, in recent years, low-dose PDT has been exploited in improving aging and wound. Low-dose ALA/MAL PDT might improve aging through promoting the proliferation of fibroblasts, blocking DNA damage, counteracting oxidative stress, inhibiting melanogenesis, and remodeling lymphatic vessels in aged skin. Promoting fibroblasts and epidermal stem cells proliferation and migration, promoting granulation tissue formation and angiogenesis and regulating the inflammatory process might be the mechanisms of low-dose ALA/MAL PDT in wound healing. Nevertheless, the positive effects of low-dose PDT have not been thoroughly investigated in dermatology, and high-quality studies are still needed to fill the relevant vacancy.

Pharmacological Agents Used in the Prevention and Treatment of Actinic Keratosis: A Review

Actinic keratosis (AK) is among the most commonly diagnosed skin diseases with potentially life-threatening repercussions if left untreated. Usage of pharmacologic agents represents one of many therapeutic strategies that can be used to help manage these lesions. Ongoing research into these compounds continues to change our clinical understanding as to which agents most benefit particular patient populations. Indeed, factors such as past personal medical history, lesion location and tolerability of therapy only represent a few considerations that clinicians must account for when prescribing appropriate treatment. This review focuses on specific drugs used in either the prevention or treatment of AKs. Nicotinamide, acitretin and topical 5-fluorouracil (5-FU) continue to be used with fidelity in the chemoprevention of actinic keratosis, although some uncertainty persists in regard to which agents should be used in immunocompetent vs. immunodeficient/immunosuppressed patients. Topical 5-FU, including combination formulations with either calcipotriol or salicylic acid, as well as imiquimod, diclofenac and photodynamic light therapy are all accepted treatment strategies employed to target and eliminate AKs. Five percent of 5-FU is regarded as the most effective therapy in the condition, although the literature has conflictingly shown that lower concentrations of the drug might also be as effective. Topical diclofenac (3%) appears to be less efficacious than 5% 5-FU, 3.75-5% imiquimod and photodynamic light therapy despite its favorable side effect profile. Finally, traditional photodynamic light therapy, while painful, appears to be of higher efficacy in comparison to its more tolerable counterpart, daylight phototherapy.

Effect of 5-Aminolevulinic Acid Photodynamic Therapy with Transfer Factor Capsules in the Treatment of Multiple Plantar Warts

BACKGROUND

Plantar warts are a common cutaneous disease of the sole of the foot caused by human papillomavirus. Photodynamic therapy has gained increasing attention in the treatment of plantar warts.

OBJECTIVE

To investigate the effect of photodynamic therapy combined with transfer factor capsules in the treatment of multiple plantar warts.

METHODS

Sixty-one patients with multiple plantar warts who visited our outpatient department from September 2017 to August 2019 were randomly divided into two groups. Twenty-three patients received photodynamic therapy (treatment group) and thirty-eight received cryotherapy (control group). Both groups also received immune modulator transfer factor capsules. Skin lesion score, numeric rating scale- (NRS-) 10 score, recurrence rate, adverse reactions, and Dermatology Life Quality Index (DLQI) were analyzed in both groups.

RESULTS

The mean skin lesion score improved from 13.39 ± 3.88 before treatment to 1.48 ± 2.50 after the last treatment in the treatment group and from 12.47 ± 2.99 before treatment to 4.47 ± 3.67 after the last treatment in the control group. The success rate after 3 months of treatment was 86.96% in the treatment group and 39.47% in the control group. After 3 months of follow-up, the recurrence rate was significantly lower in the treatment group (20%) than in the control group (53.33%). The mean DLQI score at three months after treatment was significantly lower in the treatment group (3.61 ± 1.16) than in the control group (6.31 ± 2.59).

CONCLUSION

Photodynamic therapy combined with immunomodulators significantly increased the cure rate and reduced the recurrence rate of multiple plantar warts compared with traditional cryotherapy combined with immunomodulators.

Effectiveness of photodynamic therapy with 5-aminolevulinic acid for Bowenoid papulosis: a retrospective study with long-term follow-up

BACKGROUND

Bowenoid papulosis (BP) is a rare infectious skin disease that occurs in sexually active young people. BP is associated with human papillomavirus (HPV)16 and 18 infections, spreads through sexual contact, and tends to become cancerous. Currently, there are different BP treatment methods, and few reports on the efficacy of photodynamic therapy (PDT) with 5-aminolevulinic acid (ALA) (ALA-PDT). We compared the differences in the clearance and recurrence rates of BP between the ALA-PDT group and other groups, and explored methods to improve clinical effects and reduce lesion recurrence by combining clinical retrospective data.

METHODS

We enrolled patients who were diagnosed with bowel papulosis" between January 1, 2009, and December 31, 2020. Patient information, such as ID number, hospitalization number, admission time, name, age, gender, telephone number, admission record, discharge record, outpatient medical history, HPV type analysis, histopathological examination, and treatment plan were recorded. Outcomes were obtained and recorded through outpatient visits, telephone, and online follow-ups from patients who had reached the treatment endpoint. We compared and evaluated the differences in lesion clearance rate, lesion recurrence rate, and patient satisfaction between the ALA-PDT group and other groups using statistical analysis.

RESULTS

The lesion clearance rate of the ALA-PDT group was significantly higher than that of the control group, the lesion recurrence rate was lower than that of the control group, and patient satisfaction was higher than that of the control group. The lesion clearance rate of the ALA-PDT group was higher than that of the microwave and radiofrequency groups, the lesion recurrence rate of the ALA-PDT group was significantly lower than that of the microwave and radiofrequency groups, and patient satisfaction was significantly higher than that of the microwave and radiofrequency groups. In the lesions of patients with BP, in addition to HPV16 and HPV18 types, other types were also detected, and most of them were mixed types of HPV infection. Age, sex, and duration of disease were not risk factors that affected BP recurrence.

CONCLUSIONS

ALA-PDT for BP has the advantages of high lesion clearance rate, low lesion recurrence rate, and high patient satisfaction. ALA-PDT is worthy of recommendation as the preferred treatment plan for the treatment of BP.

5-aminolevulinic acid-photodynamic therapy ameliorates cutaneous granuloma by killing drug-resistant Mycobacterium marinum

BACKGROUND

Although 5-aminolevulinic acid photodynamic therapy (ALA-PDT) has been extensively used to treat various skin diseases, its application to the treatment of cutaneous infection caused by Mycobacterium marinum (M. marinum), especially by drug-resistant M. marinum, is still unclear.

OBJECTIVES

We evaluated the efficacy of ALA-PDT on M. marinum in a mouse infection model and tested its killing effect on M. marinum in vitro. We also investigated the clinical effect of ALA-PDT on cutaneous granuloma caused by drug-resistant M. marinum.

MATERIALS AND METHODS

A total of 9 M. marinum strains isolated from patients were tested for anti-mycobacterial susceptibility. The effects of ALA-PDT on M. marinum in vitro and in mice model were investigated. Therapeutic efficacy was further assessed in two patients with cutaneous granuloma caused by drug- resistant M. marinum.

RESULTS

We demonstrated that ALA-PDT directly killed M. marinum in vitro. The cutaneous lesions on mouse paws caused by M. marinum were fully recovered 4 weeks after the ALA-PDT treatment. ALA-PDT was also effective in two patients with cutaneous infection caused by drug-resistant M. marinum. The level of intracellular ROS in M. marinum treated with ALA-PDT was significantly higher than that of M. marinum alone.

CONCLUSIONS

The results suggest that ALA-PDT is effective in treating M. marinum cutaneous infections by releasing more reactive oxygen species to kill M. marinum directly, and these effects are independent of systemic immune responses. The data highlights that ALA-PDT is a promising therapeutic choice for treatment of M. marinum cutaneous infections, especially drug-resistant M. marinum infections.

Grade-targeted nanoparticles for improved hypoxic tumor microenvironment and enhanced photodynamic cancer therapy

Background: The hypoxia of the tumor microenvironment (TME), low transfer efficiency of photosensitizers and limited diffusion distance of reactive oxygen species restrict the application of photodynamic therapy (PDT). Aim: To produce TME-responsive and effective nanoparticles for sensitizing PDT. Materials & methods: CD44 and mitochondria grade-targeted hyaluronic acid (HA)-triphenylphosphine (TPP)-aminolevulinic acid (ALA)-catalase (CAT) nanoparticles (HTACNPs) were synthesized via a modified double-emulsion method. In vitro and in vivo experiments were performed to investigate the antitumor efficacy of HTACNP-mediated PDT. Results: HTACNPs specifically targeted MV3 cells and the mitochondria and produced O₂ to relieve TME hypoxia. HTACNP-mediated PDT produced reactive oxygen species to induce irreversible cell apoptosis. HTACNP-PDT inhibited melanoma growth effectively in vivo. Conclusion: HTACNP-mediated PDT improved TME hypoxia and effectively enhanced PDT for cancer.