Photodynamic therapy, a promising treatment approach for cutaneous infectious granulomas

Cutaneous Mycobacterium marinum Treated With Photodynamic Therapy Alone and Combined With Antibiotics

This cohort study evaluated the effectiveness and safety of photodynamic therapy (PDT) alone and combined with antibiotics for the treatment of cutaneous Mycobacterium marinum infections.

Effects of ALA-PDT on the murine footpad model of Fonsecaea monophora infection and its related mechanisms in vivo

BACKGROUND

5-aminolevulinic acid photodynamic therapy (ALA-PDT) has received growing attention for treating chromoblastomycosis (CBM) and has shown efficacy in a handful of clinical case reports. However, there is insufficient information regarding the effects of ALA-PDT on Fonsecaea monophora in mouse infection model and the related mechanisms. This study investigated these issues in vivo.

METHODS

A F. monophora infection mouse model inoculated in footpads was used. Changes in the footpad volume, tissue fungal burden, and histopathological characteristics were investigated to determine the efficacy of ALA-PDT. Scavenger receptor MARCO (Macrophage receptor with collagenous structure) was further evaluated at the gene and protein levels. Serum cytokines TNF-α, GM-CSF, IL-4, and IL-10 were measured using enzyme-linked immunosorbent assay to indicate changes in the immune microenvironment after PDT.

RESULTS

ALA-PDT reduced infected footpad volume, fungal burden, and pathological inflammatory infiltration in vivo. It also increased the expression of Marco in the murine infection model. Furthermore, PDT upregulated the anti-inflammatory cytokines IL-4 and IL-10 while downregulated the pro-inflammatory cytokines TNF-α and GM-CSF in mouse serum.

CONCLUSIONS

ALA-PDT demonstrated fungicidal effects in a mouse footpad infection model with F. monophora and attenuated the inflammatory reactions. It may also assist against the intracellular fungi by the host through macrophage receptor MARCO and regulation of the immune microenvironment. This study provides scientific evidence for the protocol selection of ALA-PDT as a promising adjunctive modality for treating chromoblastomycosis.

Successful management of recurrent cutaneous granulomas caused by Candida albicans using aminolevulinic acid photodynamic therapy post-surgery: A case report

Photodynamic therapy (PDT) is a treatment that combines a photosensitive drug with light to induce phototoxic response in target cells, primarily through singlet oxygen.. Few cases have reported the combination of PDT with antifungal agents to successfully treat Candida infection. We present a case of cutaneous mass caused by Candida albicans (C.albicans) treated solely with 5-aminolevulinic acid (ALA)- PDT. A 21-year-old female presented with a cutaneous lesion on her right elbow,. characterized by erythema, nodules, and cysts that had persisted for 3 months after surgical excision. The diagnosis of infectious granulomas caused by C. albicans was confirmed through tissue histopathological, morphology and molecular sequence of the isolated pathogen. The lesion was completely resolved after two sessions of ALA-PDT adminstered 9 days apart. During the 6-month follow-up, there were no signs of relapse. This case suggested that mono-ALA-PDT can be an effective treatment option for single lesion on the body surface caused by C. albicans deep infection.

A systematic overview of strategies for photosensitizer and light delivery in antibacterial photodynamic therapy for lung infections

Antimicrobial photodynamic therapy (aPDT) emerges as a viable treatment strategy for infections resistant to conventional antibiotics. A complex interplay of factors, including intracellular photosensitizer (PS) accumulation, photochemical reaction type, and oxygen levels, determines the efficacy of aPDT. Recent progress includes the development of modified PSs with enhanced lipophilicity and target-specific strategies to improve bacterial cell wall penetration and targeting. Nanotechnology-based approaches, such as using nanomaterials for targeted PS delivery, have shown promise in enhancing aPDT efficacy. Advancements in light delivery methods for aPDT, such as transillumination of large lesions and local light delivery using fiber optic techniques, are also being explored to optimize treatment efficacy in clinical settings. The limited number of animal models and clinical trials specifically designed to assess the efficacy of aPDT for lung infections highlights the need for further research in this critical area. The potential prospects of aPDT for lung tissue infections originating from antibiotic-resistant bacterial infections are also discussed in this review.

Photodynamic application in diagnostic procedures and treatment of non-melanoma skin cancers

OPINION STATEMENT

Skin tumors commonly seen in dermatology are involved in all layers of the skin and appendages. While biopsy of affected skin remains an essential method to confirm diagnosis and to predicate tumor prognosis, it has its limitations. Recently, photodynamic diagnosis (PDD) has demonstrated high sensitivity in detecting affected skin and mucosal tissues, providing valuable guidance for precision surgery to resect skin and mucosal tumors. In this review, we summarized the literatures concerning the applications of PDD in diagnostic process and treatment of skin and mucosal conditions such as actinic keratoses (AK), basal cell carcinoma (BCC), squamous cell carcinoma (SCC), Bowen's disease (BD) and extramammary Paget's disease (EMPD). The findings suggest that PDD holds substantial promise for expanding clinical applications and deserves further research exploration.

Antimicrobial Resistance: Is There a 'Light' at the End of the Tunnel?

In recent years, with the increases in microorganisms that express a multitude of antimicrobial resistance (AMR) mechanisms, the threat of antimicrobial resistance in the global population has reached critical levels. The introduction of the COVID-19 pandemic has further contributed to the influx of infections caused by multidrug-resistant organisms (MDROs), which has placed significant pressure on healthcare systems. For over a century, the potential for light-based approaches targeted at combatting both cancer and infectious diseases has been proposed. They offer effective killing of microbial pathogens, regardless of AMR status, and have not typically been associated with high propensities of resistance development. To that end, the goal of this review is to describe the different mechanisms that drive AMR, including intrinsic, phenotypic, and acquired resistance mechanisms. Additionally, the different light-based approaches, including antimicrobial photodynamic therapy (aPDT), antimicrobial blue light (aBL), and ultraviolet (UV) light, will be discussed as potential alternatives or adjunct therapies with conventional antimicrobials. Lastly, we will evaluate the feasibility and requirements associated with integration of light-based approaches into the clinical pipeline.