A randomized intraindividual comparative study of methyl-5-aminolaevulinate vs. 5-aminolaevulinic acid nanoemulsion (BF-200 ALA) in photodynamic therapy for actinic keratosis of the face and scalp

ALA-PDT promotes the death and contractile capacity of hypertrophic scar fibroblasts through inhibiting the TGF-β1/Smad2/3/4 signaling pathway

BACKGROUND

Hypertrophic scars, an abnormal wound-healing response to burn injuries, are characterized by massive fibroblast proliferation and excessive deposition of extracellular matrix and collagen. 5-aminolevulinic acid-based photodynamic therapy (ALA-PDT) is a promising therapy for hypertrophic scar, details of the mechanisms remain to be elucidated. In this study, we aimed to investigate the molecular mechanisms involved in ALA-PDT against hypertrophic scar fibroblasts.

METHODS

The morphologies of hypertrophic scar fibroblasts (HSFs) treated with ALA-PDT were observed under a light microscopy. The viability of HSFs was detected using the CCK-8 assay. HSFs-populated collagen gel contraction assays were conducted to examine the fibroblast contractility and the cytotoxicity of HSFs in 3D collagen tissues were observed using confocal microscopy. The effect of ALA-PDT on TGF-β1/Smad2/3/4 signaling pathway activation and effector gene expression were verified by immunoprecipitation, western blot and real-time quantitative PCR analysis.

RESULTS

We observed significant changes in cell morphology after ALA-PDT treatment of HSFs. As ALA concentration and light dose increased, the viability of HSFs significantly decreased. ALA-PDT can significantly alleviate the contractile capacity and promote the death of HSFs induced by TGF-β1 treatment in a three-dimensional collagen culture model. TGF-β1 treatment of HSFs can significantly induce phosphorylation of Smad2/3 (p-Smad2/3) in whole cells, as well as p-Smad2/3 and Smad4 proteins into the nucleus and increase the mRNA levels of collagen 1/3 and α-SMA. ALA-PDT hampers the TGF-β1-Smad2/3/4 signaling pathway activation by inducing K48-linked ubiquitination and degradation of Smad4.

CONCLUSIONS

Our results provide evidence that ALA-PDT can inhibit fibroblast contraction and promote cell death by inhibiting the activation of the TGF-β1 signaling pathway that mediates hypertrophic scar formation, which may be the basis for the efficacy of ALA-PDT in the treatment of hypertrophic scars.

The impact of photodynamic therapy on skin homeostasis in patients with actinic keratosis: A prospective observational study

BACKGROUND

Photodynamic therapy (PDT) is an effective treatment for actinic keratosis (AKs), but there is little information on how PDT affects skin barrier function. The objectives of this study are: To compare skin barrier function between skin with AKs and healthy skin and to evaluate the impact of PDT on skin homeostasis in patients with AKs.

METHODS

A prospective observational study was conducted in patients with AKs to evaluate epidermal barrier function and skin homeostasis before and 1 ek after receiving PDT.

RESULTS

A total of 21 subjects were included in the study, male/female ratio was 17:4, mean age was 75.86 years. The number of AKS observed before starting treatment was reduced with respect to those diagnosed 1 month after starting PDT (14.83 vs. 1.91, p < 0.0001). Application of PDT for treating AKs modifies epidermal barrier function. Immediately after the first session temperature, transepidermal water loss (TEWL), stratum corneum hydration (SCH) and total antioxidant capacity (TAC) increased while pH decreased on lesional skin. After 1-month follow-up, the only remained change was the increased in SCH. Higher increases in temperature were observed when using occlusive PDT compared to mixed modality. 5-ALA and M-ALA seem to have a similar impact on skin barrier.

CONCLUSIONS

PDT can improve skin barrier function in patients with AKs. Skin homeostasis parameters can be used to assess efficacy and optimize dosing.

Photodynamic Therapy for Field Cancerization in the Skin: Where Do We Stand?

INTRODUCTION

Photodynamic therapy (PDT) with a photosensitizer is available for the treatment of multiple actinic keratoses (AKs) in a restricted skin area or, as it is established, for the field-cancerized skin.

OBJECTIVES

Our review aims to present the up-to-date literature on skin field cancerization using PDT employing different topical photosensitizers, modified light delivery protocols and combination treatments to obtain excellent efficacy and safety in everyday clinical practice.

METHODS

We sought PubMed, MEDLINE, Scopus, OVID, Embase, Science Direct, Cochrane Library, Research Gate and Google Scholar for [(aminolevulinic acid OR aminolevulinate) AND photodynamic therapy] with (field-directed OR field cancerization, (actinic keratosis), and (efficacy OR effectiveness OR pain OR tolerability) for studies published until February 2023.

RESULTS

Advantages of PDT compared to the other field treatments, including imiquimod, 5-fluorouracil, ingenol mebutate gel and diclofenac, reported better cosmetic outcomes and greater patient satisfaction. On the other hand, some drawbacks of field PDT include pain and treatment duration. Alternate illumination methods have also been investigated, including daylight as a light source. Pretreating the affected area may enhance photosensitizer absorption leading to better therapeutic results, while combinational treatments have also been tested. Patients prefer daylight PDT to traditional light sources since it is more well-tolerated and equally effective. Even as a preventive treatment, field PDT yields promising outcomes, especially for high-risk individuals, including organ transplant recipients.

CONCLUSIONS

This review provides a thorough display of the field of PDT on cancerized skin, which will facilitate physicians in applying PDT more efficiently and intuitively.

Lipid-core nanoparticles: Classification, preparation methods, routes of administration and recent advances in cancer treatment

Nanotechnological drug delivery platforms represent a new paradigm for cancer therapeutics as they improve the pharmacokinetic profile and distribution of chemotherapeutic agents over conventional formulations. Among nanoparticles, lipid-based nanoplatforms possessing a lipid core, that is, lipid-core nanoparticles (LCNPs), have gained increasing interest due to lipid properties such as high solubilizing potential, versatility, biocompatibility, and biodegradability. However, due to the wide spectrum of morphologies and types of LCNPs, there is a lack of consensus regarding their terminology and classification. According to the current state-of-the-art in this critical review, LCNPs are defined and classified based on the state of their lipidic components in liquid lipid nanoparticles (LLNs). These include lipid nanoemulsions (LNEs) and lipid nanocapsules (LNCs), solid lipid nanoparticles (SLNs) and nanostructured lipid nanocarriers (NLCs). In addition, we present a comprehensive and comparative description of the methods employed for their preparation, routes of administration and the fundamental role of physicochemical properties of LCNPs for efficient antitumoral drug-delivery application. Market available LCNPs, clinical trials and preclinical in vivo studies of promising LCNPs as potential treatments for different cancer pathologies are summarized.

The Role and Effectiveness of Photodynamic Therapy on Patients With Actinic Keratosis: A Systematic Review and Meta-Analysis

Actinic keratoses (AKs) are the most common neoplastic lesions and are recognized as a precursor to squamous cell skin cancer. Photodynamic therapy (PDT) is a therapeutic option for multiple AKs in line with field cancerization. The aim of this study was to assess the effectiveness of PDT on patients with AKs using a meta-analysis, in order to evaluate the possible superiority of one treatment over the others. For this purpose, the PubMed, MEDLINE, Scopus, OVID, Science Direct, British Journal of Dermatology, Research Gate, and Embase databases were searched in March 2022. The search terms used were 'photodynamic therapy' and 'actinic keratosis'. We utilized the random-effects meta-analysis model to compare methyl aminolevulinate PDT (MAL-PDT) and the combination of a nanoscale-lipid vesicle formulation with the prodrug 5-aminolevulinic acid (BF-200 ALA) on a complete response (CR) of the lesions. Our meta-analysis indicated that the comparison of BF-200 ALA versus MAL-PDT showed marginally higher CRs than MAL-PDT.

A Systematic Review and Meta-Analysis of Interventions for Actinic Keratosis from Post-Marketing Surveillance Trials

Multiple interventions are available for the treatment of actinic keratosis (AK) showing high efficacy in pivotal trials. However, data from post-marketing surveillance studies have received little attention until now. Here, we systematically investigate interventions for AK from post-marketing surveillance trials as a proxy for real-world efficacy and tolerability. A systematic literature search was conducted in Medline, Embase, and CENTRAL. Pertinent trial registers were hand-searched until 25 March 2020. Results were pooled using a random-effects model to calculate pooled proportions and relative risks (RR) or were described qualitatively. Eleven records with a total sample size of n = 4109 were included. Three of the studies had an active-controlled design, while seven were single-armed. Participant complete clearance ranged from 23.1% for diclofenac sodium 3% gel to 88.9% for ingenol mebutate 0.05% gel. The lesion-specific clearance rate for photodynamic therapy (PDT) was 74% (95% confidence interval (CI) 56–87%). The recurrence rate was significantly higher for diclofenac sodium 3% in comparison to imiquimod 5% cream (RR 1.10, 95% CI 1.02–1.1.8) and ranged from 10.6% for ingenol mebutate 0.015% gel to 23.5% for PDT. Few patients discontinued the trials due to adverse events. The results from the majority of the post-marketing surveillance studies deviated from those of pivotal trials.

European Dermatology Forum guidelines on topical photodynamic therapy 2019 Part 1: treatment delivery and established indications - actinic keratoses, Bowen's disease and basal cell carcinomas

Topical photodynamic therapy (PDT) is a widely approved therapy for actinic keratoses, Bowen's disease (squamous cell carcinoma in situ), superficial and certain thin basal cell carcinomas. Recurrence rates when standard treatment protocols are used are typically equivalent to existing therapies, although inferior to surgery for nodular basal cell carcinoma. PDT can be used both as lesional and field therapies and has the potential to delay/reduce the development of new lesions. A protocol using daylight to treat actinic keratoses is widely practised, with conventional PDT using a red light after typically a 3-h period of occlusion employed for other superficial skin cancer indications as well as for actinic keratoses when daylight therapy is not feasible. PDT is a well-tolerated therapy although discomfort associated with conventional protocol may require pain-reduction measures. PDT using daylight is associated with no or minimal pain and preferred by patient. There is an emerging literature on enhancing conventional PDT protocols or combined PDT with another treatment to increase response rates. This guideline, published over two parts, considers all current approved and emerging indications for the use of topical PDT in dermatology, prepared by the PDT subgroup of the European Dermatology Forum guidelines committee. It presents consensual expert recommendations reflecting current published evidence.

Efficacy and safety of photodynamic therapy with amino-5-laevulinate nanoemulsion versus methyl-5-aminolaevulinate for actinic keratosis: A meta-analysis

BACKGROUND

Photodynamic therapy is an effective treatment for actinic keratosis. 5-aminolevulinic acid nanoemulsion (BF-200 ALA) and methyl-5-aminolevulinate (MAL) are both prodrugs for the treatment of actinic keratosis with photodynamic therapy. A comparison of the efficacy and safety between the drugs is critical for clinical practice.

OBJECTIVES

To investigate if photodynamic therapy in combination with BF-200 ALA is superior to photodynamic therapy with MAL for actinic keratosis.

METHODS

We performed a meta-analysis to investigate the combination of photodynamic therapy with BF-200 ALA and with MAL. The PubMed, Cochrane Library, Web of Science and EMBASE databases were searched to select eligible randomized controlled trials. Our search was conducted on April 1, 2019, and included the search terms "5-aminolevulinic acid nanoemulsion or BF-200 ALA", "methyl-5-aminolevulinate or methyl aminolaevulinate" and "actnic keratosis". Cochrane Risk of Bias Tool was used to estimate the risk of bias.

RESULTS

The meta-analysis consisted of 5988 actinic keratosis lesions in five eligible randomized controlled trials, with a total of 2953 actinic keratosis lesions treated with BF-200 ALA and 3035 actinic keratosis lesions treated with MAL. BF-200 ALA in combination with photodynamic therapy showed significantly higher overall complete clearance rates (RR: 1.07, 95% CI 1.02-1.12, p = 0.01) and 3 month complete clearance rates (RR: 1.09, 95% CI 1.06-1.12, p < 0.00001) compared to MAL. A subgroup analysis was performed for photodynamic therapy combined with BF-200 ALA, revealing increased complete clearance rates of grade II-III lesions in comparison with MAL (RR: 1.24, 95% CI 1.05-1.46, p = 0.01). Compared with MAL, the pooled relative risk for the meta-analysis for recurrence was 0.67 (95% CI 0.48-0.92, p = 0.01) at 12 month after BF-200 ALA treatment.

CONCLUSION

Photodynamic therapy with BF-200 ALA has a 9% better chance of complete clearance at 3 months and a 24% better chance of grade II-III lesions after treatment than with MAL for patients with actinic keratosis.