A Critical Reappraisal of Off-Label Use of Photodynamic Therapy for the Treatment of Non-Neoplastic Skin Conditions

Hyperbranched Polymers: Recent Advances in Photodynamic Therapy against Cancer

Hyperbranched polymers are a class of three-dimensional dendritic polymers with highly branched architectures. Their unique structural features endow them with promising physical and chemical properties, such as abundant surface functional groups, intramolecular cavities, and low viscosity. Therefore, hyperbranched-polymer-constructed cargo delivery carriers have drawn increasing interest and are being utilized in many biomedical applications. When applied for photodynamic therapy, photosensitizers are encapsulated in or covalently incorporated into hyperbranched polymers to improve their solubility, stability, and targeting efficiency and promote the therapeutic efficacy. This review will focus on the state-of-the-art studies concerning recent progress in hyperbranched-polymer-fabricated phototherapeutic nanomaterials with emphases on the building-block structures, synthetic strategies, and their combination with the codelivered diagnostics and synergistic therapeutics. We expect to bring our demonstration to the field to increase the understanding of the structure-property relationships and promote the further development of advanced photodynamic-therapy nanosystems.

Photodynamic Therapy, a successful treatment for granular parakeratosis

Granular parakeratosis is characterized by variably hyperkeratotic brownish papules or plaques, mostly found on flexures. Different treatments have been suggested with variable results. We present a series of 3 cases successfully treated with one session of methyl-aminolevulinate photodynamic therapy, showing resolution of the lesions and symptoms within less than 2 weeks, as a new safe and effective therapeutic option.

Sulphur- and Selenium-for-Oxygen Replacement as a Strategy to Obtain Dual Type I/Type II Photosensitizers for Photodynamic Therapy

The effect on the photophysical properties of sulfur- and selenium-for-oxygen replacement in the skeleton of the oxo-4-dimethylaminonaphthalimide molecule (DMNP) has been explored at the density functional (DFT) level of theory. Structural parameters, excitation energies, singlet–triplet energy gaps (ΔES-T), and spin–orbit coupling constants (SOC) have been computed. The determined SOCs indicate an enhanced probability of intersystem crossing (ISC) in both the thio- and seleno-derivatives (SDMNP and SeDMNP, respectively) and, consequently, an enhancement of the singlet oxygen quantum yields. Inspection of Type I reactions reveals that the electron transfer mechanisms leading to the generation of superoxide is feasible for all the compounds, suggesting a dual Type I/Type II activity.

Photodynamic Therapy Used to Treat an HIV Patient with an Efflorescence of Viral Warts after HAART Therapy

Healing from viral warts lesions can be hard to achieve in immunocompromised subjects like HIV-positive patients. The therapeutic target in immunocompetent subjects can be reached using different methods, including topical ointments, cryotherapy, laser therapy, imiquimod, and photodynamic therapy (PDT). We present a case of a male HIV-positive patient who came to the Dermatology department with multifocal wart lesions on his face, auricular, and retro-auricular areas after treatment with highly active antiretroviral therapy (HAART). In our case, surprisingly, only one session of PDT proved to induce complete regression of lesions which, despite their thickness, had a much more robust response to treatment than we could have possibly expected. After a brief review of the literature, it is possible to state that PDT revealed itself to be a valid option in immunocompromised patients who have a major risk of relapse.

The effect of the ketogenic diet on Acne: Could it be a therapeutic tool?

Acne is a chronic inflammatory disease of the pilosebaceous unit resulting from androgen-induced increased sebum production, altered keratinization, inflammation, and bacterial colonization of the hair follicles of the face, neck, chest and back by Propionibacterium acnes. Overall, inflammation and immune responses are strongly implicated in the pathogenesis of acne. Although early colonization with Propionibacterium acnes and family history may play an important role in the disease, it remains unclear exactly what triggers acne and how treatment affects disease progression. The influence of diet on acne disease is a growing research topic, yet few studies have examined the effects of diet on the development and clinical severity of acne disease, and the results have often been contradictory. Interestingly, very low-calorie ketogenic diet (VLCKD) has been associated with both significant reductions in body weight and inflammatory status through the production of ketone bodies and thus it has been expected to reduce the exacerbation of clinical manifestations or even block the trigger of acne disease. Given the paucity of studies regarding the implementation of VLCKD in the management of acne, this review aims to provide evidence from the available scientific literature to support the speculative use of VLCKD in the treatment of acne.

Systematic review of photodynamic therapy for the treatment of hidradenitis suppurativa

OBJECTIVE

To perform a systematic review of available literature regarding the use of 5-aminolevulinic acid (ALA) and ALA derivative photodynamic therapy (PDT) in the treatment of hidradenitis suppurativa (HS) and provide recommendations on its use.

METHODS

A systematic review was performed of all published studies up to September 1, 2019 from nine databases, including PubMed, that evaluated PDT in the treatment of HS. For each study, quality of evidence and risk of bias was evaluated. Recommendations from the body of evidence were created based on Strength of Recommendation and Taxonomy (SORT) criteria.

RESULTS

Eighteen studies met inclusion criteria. The majority of studies had a high risk of bias. Blue light PDT with 20% ALA and red light PDT with 16% methyl aminolevulinate (MAL) demonstrated some benefit based on a small number of poor-quality studies with a high risk of bias (Grade C, level III evidence). The most promising results were for 1%-5% ALA with intralesional diode, with good to complete response in 78%-94% of anatomic sites treated (Grade B, level II evidence).

LIMITATIONS

The majority of studies contained high levels of bias, with significant heterogeneity between studies. Conclusions are limited by small samples sizes, lack of randomized controlled trials, and differing protocols.

CONCLUSION

Further studies are needed to determine the clinical efficacy of 20% ALA with blue light and MAL with red light. Intralesional diode PDT shows the most promise and warrants further investigation in larger, randomized controlled trials.

Accelerating skin regeneration and wound healing by controlled ROS from photodynamic treatment

Cellular metabolisms produce reactive oxygen species (ROS) which are essential for cellular signaling pathways and physiological functions. Nevertheless, ROS act as “double-edged swords” that have an unstable redox balance between ROS production and removal. A little raise of ROS results in cell proliferation enhancement, survival, and soft immune responses, while a high level of ROS could lead to cellular damage consequently protein, nucleic acid, and lipid damages and finally cell death. ROS play an important role in various pathological circumstances. On the contrary, ROS can show selective toxicity which is used against cancer cells and pathogens. Photodynamic therapy (PDT) is based on three important components including a photosensitizer (PS), oxygen, and light. Upon excitation of the PS at a specific wavelength, the PDT process begins which leads to ROS generation. ROS produced during PDT could induce two different pathways. If PDT produces control and low ROS, it can lead to cell proliferation and differentiation. However, excess production of ROS by PDT causes cellular photo damage which is the main mechanism used in cancer treatment. This review summarizes the functions of ROS in living systems and describes role of PDT in production of controllable ROS and finally a special focus on current ROS-generating therapeutic protocols for regeneration and wound healing.

Chalcogen Effects in the Photophysical Properties of Dimethylamino-1,8-naphthalimide Dyes Revealed by DFT Investigation

Thionation of carbonyl groups of known dyes is a rapidly emerging strategy to propose an advance toward heavy-atom-free photosensitizers to be used in photodynamic therapy (PDT). The sulfur-for-oxygen replacement has recently proved to enhance the singlet oxygen quantum yield of some existing fluorophores and to shift the absorption band at longer wavelengths. Drawing inspiration from this challenging evidence, the effect of both sulfur- and selenium-for-oxygen replacement in the skeleton of the oxo-4-dimethylamino-1,8-naphthalimide molecule (DMN) has been analyzed by means of a DFT study. The thio- and seleno-derivatives (SDMN and SeDMN, respectively) have been shown to offer the possibility to access a multitude of ISC (intersystem crossing) pathways involved in the triplet deactivation mechanisms with a consequent enhancement of the singlet oxygen production, also arising from the change of orbital type involved in the radiationless ¹nπ* → ³ππ* transitions. Moreover, the change in nature from a ¹ππ* to a ¹nπ* observed in the SeDMN has been revealed to be crucial to reach more clinically useful regions of the spectrum suggesting that the selenium-for-oxygen replacement can be proposed as a strategy to achieve more suitable PDT agents while proposing an advance toward heavy-atom-free PSs.

Management of Difficult-to-Treat Warts: Traditional and New Approaches

Warts are regularly treated by dermatologists, and while many respond readily to first-line treatments, others may represent a therapeutic challenge. Large, deep, numerous, and extensive warts; treatment-resistant lesions with higher risk for side effects, such as hypopigmentation; or patients unable to tolerate or comply with our treatment regimen, may need alternative treatment options. In this work we review the characteristics of select modalities that should be considered for difficult-to-treat warts. We discuss efficacy and tolerability data as well as practical features that can guide us to select the best treatment for every scenario. Novel approaches, still in an investigational phase, are also discussed to illustrate potential future directions of wart treatment.

[Photodynamic therapy-trends and new developments]

Photodynamic therapy (PDT) is a licensed and established procedure for the treatment of actinic keratosis, basal cell carcinoma, and Bowen's disease, but there are several new and clinically relevant developments and trends. These concern on the one hand the main components of PDT, which are the photosensitizer and the light source. Furthermore, modifications and therapy combinations have been developed that lead to an improved therapeutic efficacy. An important aspect of field-directed PDT is also skin cancer prevention. Finally, PDT has been used successfully for nonlicensed indications including inflammatory diseases and skin rejuvenation. This article focuses on these new developments and on recent guideline recommendations.