Photodynamic therapy treats acne by altering the composition of the skin microbiota

Photodynamic Therapy with Protoporphyrin IX Precursors Using Artificial Daylight Improves Skin Antisepsis for Orthopedic Surgeries

Classical preoperative skin antisepsis is insufficient in completely eliminating bacterial skin colonization for arthroplasty. In contrast, photodynamic therapy (PDT) with red light and methyl-aminolevulinate (MAL), combined with skin antisepsis, led to the absence of bacterial growth in healthy participants, though with local skin erythema, posing an obstacle for orthopedic surgery. Therefore, we explored whether artificial daylight PDT (PDT-DL) was superior to red light. Twenty healthy participants were allocated to either 5-aminolevulinic acid-(5-ALA) PDT-DL (n = 10) or MAL-PDT-DL (n = 10) before antisepsis with povidone-iodine/alcohol. Skin swabs from the groin were taken to cultivate bacteria at baseline, after PDT-DL, and after the subsequent antisepsis. Additional swabs were taken on day 4 before and after antisepsis without PDT. The contralateral groin of each participant and of ten additional healthy volunteers served as the control (n = 30). In selected participants, 16S rRNA-based amplicon deep sequencing was performed. All participants showed a baseline bacterial colonization. After a PDT-DL with skin antisepsis, bacterial growth occurred in three (30%) and in one (10%) participants with 5-ALA and MAL, respectively, compared to the sixteen (55%) participants in the control group. On day 4, three (30%) participants per group showed positive cultures post antisepsis. Adverse effects were reported in six (60%) and zero (0%) participants for 5-ALA- and MAL-PDT-DL, respectively. The skin bacteriome changes correlated with the bacterial culture results. The MAL-PDT-DL with skin antisepsis significantly increased bacterial reduction on the skin without adverse effects. This offers an opportunity to prevent infections in arthroplasty patients and reduce antibiotic use, thus contributing to antibiotic stewardship goals emphasized in the One Health approach.

Effects of Light and Laser Therapies on the Microecosystem of Sebaceous Glands in Acne Treatment

BACKGROUND

Acne vulgaris (acne) is one of the most common skin diseases with complex pathogenesis. Numerous studies have shown that the microecosystem of sebaceous glands and Cutibacterium acnes play key roles in its pathogenesis. Antibiotics targeting C. acnes have been widely used in acne treatment, but the growing prevalence of antibiotic resistance has become alarming. Further research into the microecosystem of sebaceous glands and the role of specific C. acnes phylotypes in acne pathogenesis has led to a paradigm shift in acne treatment. Currently, non-antibiotic therapies such as light therapy and laser therapy are becoming increasingly popular, opening up new opportunities in acne management.

METHODS

Studies on the microecosystem of sebaceous glands associated with acne and the effects of light and laser therapies on the microecosystem in acne treatment were retrieved from the PubMed database.

RESULTS

Dysbiosis of the microecosystem of the pilosebaceous unit is closely related to the pathogenesis of acne. Light and laser therapies have an impact on the microecosystem of the pilosebaceous unit in acne treatment.

CONCLUSIONS

Light and laser therapies are the popular alternative options in acne treatment. The mechanisms of their effect on the microecosystem of sebaceous glands are not completely clear and require further research, especially for laser therapy.

Paenibacillus exopolysaccharide alleviates Malassezia-induced skin damage: Enhancing skin barrier function, regulating immune responses, and modulating microbiota

Numerous studies have established a strong association between Malassezia and various skin disorders, including atopic dermatitis. Finding appropriate methods or medications to alleviate Malassezia-induced skin damage is of notable public interest. This study aimed to evaluate the therapeutic effect of the exopolysaccharide EPS1, produced by Paenibacillus polymyxa, on Malassezia restricta-induced skin damage. In vitro assays indicated that EPS1 reduced the expression of pro-inflammatory cytokine genes in TNF-α-induced HaCaT cells. In a murine model, EPS1 was found to mitigate clinical symptoms, reduce epidermal thickness and mast cell infiltration, improve skin barrier function, decrease pro-inflammatory cytokine levels associated with type 17 inflammation, enhance Tregs in the spleen, upregulate the transcription of Treg-related genes in skin lesions, and modulate the skin microbiota. This study is the first to report the alleviating effect of Paenibacillus exopolysaccharide on Malassezia-induced skin inflammation and its impact on the skin microbiota. These findings support the potential of Paenibacillus exopolysaccharides as consumer products and therapeutic agents for managing Malassezia-induced skin damage by improving skin barrier function, modulating immune responses, and influencing skin microbiota.

Acne and the cutaneous microbiome: A systematic review of mechanisms and implications for treatments

Acne vulgaris is a pervasive skin disease characterized by inflammation of sebaceous units surrounding hair follicles. It results from the complex interplay between skin physiology and the intricate cutaneous microbiome. Current acne treatments, while effective, have major limitations, prompting a shift towards microbiome-based therapeutic approaches. This study aims to determine the relationship between acne and the cutaneous microbiome, assess the effects of current treatments on the cutaneous microbiome and explore the implications for developing new therapies. A systematic review was performed using PubMed and SCOPUS databases within the last 10 years. Methodological quality was assessed independently by two authors. The search retrieved 1830 records, of which 26 articles met the inclusion criteria. Meta-analysis of alpha diversity change was assessed using fixed and randomized effect models per therapeutic group. Eight studies pertain to the role of the cutaneous microbiome in acne, identifying C. acnes, S. aureus and S. epidermidis as key contributors through overproliferation, commensalism or dysbiosis. Eleven studies discuss current acne treatments, including doxycycline (1), topical benzoyl peroxide (BPO) (4), isotretinoin (2), sulfacetamide-sulfur (SSA) (2) and aminolevulinic acid-photodynamic therapy (ALA-PDT) (2), identified as modulating the cutaneous microbiome as a mechanism of efficacy in acne treatment. Seven studies discuss new treatments with topical probiotics, plant derivatives and protein derivatives, which contribute to acne clearance via modulation of dysbiosis, inflammatory markers and diversity indexes. A meta-analysis of the effects of existing therapeutics on the cutaneous microbiome identified benzoyl peroxide as the only treatment to facilitate significant change in diversity. Despite the heterogeneity of study types and microbiome classifications limiting the analysis, this review underscores the complexity of microbial involvement in acne pathogenesis. It delineates the effects of acne therapeutics on microbial diversity, abundance and composition, emphasizing the necessity for personalized approaches in acne management based on microbiome modulation.

Targeted precision cryotherapy for acne vulgaris

BACKGROUND

Acne vulgaris poses a significant dermatological challenge, necessitating alternative treatments due to limitations and side effects associated with current therapies. This pilot clinical trial investigated the feasibility and efficacy of precision cryotherapy for acne vulgaris.

METHODS

A total of 20 volunteers underwent targeted precision cryotherapy using a carbon dioxide-based device. Treatment outcomes were assessed using various parameters, including Investigator Global Assessment (IGA) score, acne lesion count, erythema index (EI), global evaluation score, and participant satisfaction. Safety monitoring included adverse event reporting and physical examination.

RESULTS

Precision cryotherapy demonstrated a significant reduction (90.25%) in the acne lesion count by week 4, with clinical improvement indicated by IGA score reduction (p < 0.001). The EI showed notable improvements at weeks 1, 2, and 4. The global evaluation score demonstrated a 75%-100% clinical improvement at Visit 4. Participants reported high satisfaction (6.75 ± 0.79) with the procedure. No adverse event or discomfort was reported.

CONCLUSION

Precision cryotherapy effectively improved acne lesions, which was safe and satisfactory for participants. These findings suggest its potential as an alternative therapeutic modality, especially for populations with limited treatment options. Further research is needed to validate the results and explore underlying mechanisms.

Photodynamic therapy alone or in combination to counteract bacterial infections

INTRODUCTION

Antibacterial photodynamic therapy presents a promising alternative to antibiotics, with potential against multidrug-resistant bacteria, offering broad-spectrum action, reduced resistance risk, and improved tissue selectivity.

AREAS COVERED

This manuscript reviews patent literature in the field of antibacterial photodynamic therapy through the period of 2019-2023. All data are from the US and European patent databases and SciFinder.

EXPERT OPINION

Antibacterial photodynamic therapy (PDT) is an appealing approach for treating bacterial infections, especially biofilm-related ones, by releasing reactive oxygen species (ROS) upon light activation. Its success is driven by a growing variety of photosensitizers (PSs) with tailored properties, like water solubility, controllable surface charge, and ROS generation efficiency. Among them, Aggregation Induced Emission (AIE)-type PSs are promising, demonstrating enhanced efficacy when aggregated in biological environments. However, the penetration of pristine PSs into bacterial biofilms within deep tissues or complex anatomical regions is limited, reducing their antibacterial effectiveness. To address this, nanotechnology has been integrated into antibacterial PDT to synthesize various nano-PSs. This adaptability allows seamless integration with other antimicrobial treatments, offering a comprehensive approach to combat localized infections, especially in dentistry and dermatology. By combining PSs with complementary therapies, antibacterial PDT offers a multifaceted strategy for effective microbial control and management.

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.

Dendrobium officinale flowers' topical extracts improve skin oxidative stress and aging

BACKGROUND

Dendrobium officinale flowers (DOF) have the effects of antiaging and nourishing yin, but it lacks pharmacological research on skin aging.

OBJECTIVE

Confirming the role of DOF in delaying skin aging based on the "in vitro animal-human" model.

METHODS

In this experiment, three kinds of free radical scavenging experiments in vitro, D-galactose-induced aging mouse model, and human antiaging efficacy test were used to test whether DOF can improve skin aging through anti-oxidation.

RESULTS

In vitro experiment shows that DOF has certain scavenging effect on 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical, hydroxyl free radical, and superoxide free radical, and its IC50 is 0.2090 μg/mL, 15.020, and 1.217 mg/mL respectively. DOF can enhance the activities of T-AOC, SOD, CAT, and GSH Px in the serum of aging mice, increase the content of GSH, and reduce the content of MDA when administered with DOF of 1.0, 2.0, and 4.0 g/kg for 6 weeks. In addition, it can enhance the activity of SOD in the skin of aging mice, increase the content of Hyp, and decrease the content of MDA, activated Keap1/Nrf2 pathway in the skin of aging mice. Applying DOF with a concentration of 0.2 g/mL on the face for 8 weeks can significantly improve the skin water score and elasticity value, reduce facial wrinkles, pores, acne, and UV spots, and improve the facial brown spots and roughness.

CONCLUSION

DOF can significantly improve skin aging caused by oxidative stress, and its mechanism may be related to scavenging free radicals in the body and improving skin quality.

Optimization of the Erythrosine-mediated photodynamic therapy against Escherichia coli using response surface methodology

BACKGROUND

The efficacy of photodynamic therapy (PDT) depends on the combination of light and a photosensitizer for inactivation of microorganisms. However, finding the ideal conditions for the factors involved in this technique is time and cost-consuming. The rotational composite central design (RCCD) is a tool that can be allied with PDT to achieve precise results within a shorter working time.

METHODS

This study used the response surface methodology to optimize the parameters of PDT mediated by Erythrosine (ERY) and green light-emitting diodes (LED) in different Escherichia coli strains by applying RCCD.

RESULTS

The RCCD predicted optimum values of ERY and light exposure on PDT. According to the experimental results, the light exposure time showed the most significant influence on the inactivation of the evaluated bacteria. The optimized operating conditions were validated in laboratory tests, and no viable cells were recovered with ERY at 116 µmol L-1 and 30 min of light (33.34 J cm2) for E. coli ATCC 25922, 108 µmol L-1 and 40 min (44.38 J cm2) for E. coli ATCC 35218, and 108 µmol L-1 and 29.3 min (32.5 J cm2) for E. coli O157:H7 EDL 933.

CONCLUSION

The adjusted polynomial models provided accurate information on the combined effects of ERY and lighting time with green LED on PDT. The application of the RCCD, in addition to reducing the number of experiments, also allows for increased quantity and quality of the results. Therefore, surface response methodology combined with PDT is a promising approach to inactivate E. coli.

The updates and implications of cutaneous microbiota in acne

Acne is a chronic inflammatory skin disorder that profoundly impacts the quality of life of patients worldwide. While it is predominantly observed in adolescents, it can affect individuals across all age groups. Acne pathogenesis is believed to be a result of various endogenous and exogenous factors, but the precise mechanisms remain elusive. Recent studies suggest that dysbiosis of the skin microbiota significantly contributes to acne development. Specifically, Cutibacterium acnes, the dominant resident bacterial species implicated in acne, plays a critical role in disease progression. Various treatments, including topical benzoyl peroxide, systemic antibiotics, and photodynamic therapy, have demonstrated beneficial effects on the skin microbiota composition in acne patients. Of particular interest is the therapeutic potential of probiotics in acne, given its direct influence on the skin microbiota. This review summarizes the alterations in skin microbiota associated with acne, provides insight into its pathogenic role in acne, and emphasizes the potential of therapeutic interventions aimed at restoring microbial homeostasis for acne management.