Photodynamic Inhibition of Herpes Simplex Virus 1 Infection by Tricationic Amphiphilic Porphyrin with a Long Alkyl Chain

Novel one-/two-photon excited carbazole/quinolinium photosensitizers manifest nanomolar and hypoxia-resistant tumor photodynamic therapy by accelerating apoptosis, ferroptosis, and autophagy

Photodynamic therapy (PDT) holds potential in cancer treatment, but the development of photosensitizers with high-efficient PDT remains a challenge. Herein, we designed and synthesized a series of novel tricyclic carbazole/quinolinium hybrids-KNKQ, KAKQ, and KPKQ-as photosensitizers, and subsequently evaluated their photodynamic anticancer activities and the associated mechanisms. Among them, KPKQ exhibited the most prominent one-/two-photon activated photodynamic characteristics, generating •O2-, •OH, and 1O2. Particularly, the 1O2 quantum yield of KPKQ was 3∼9-fold stronger than KNKQ and KAKQ. Most interestingly, KPKQ demonstrated nanomolar-level and hypoxic-overcoming single-photon phototoxicities with IC50 values of 27∼43 nM (PIs = 46-54), significantly surpassing existing tricyclic carbazole photosensitizers, and also exerted potent photodynamic therapeutic effects (IC50s = 0.13-0.20 μM) via two-photon excitation at 808 nm. Furthermore, KPKQ significantly promoted mitochondrial damage, cell apoptosis, and DNA lesion via reducing Bcl-2 level and increasing the levels of Bax, cleaved-Caspase-3, and γ-H2AX. Concurrently, KPKQ lowered GSH/GPX4 levels and elevated malondialdehyde to trigger ferroptosis. Additionally, KPKQ powerfully promoted autophagy through boosting LC3-II and Beclin-1 expression, thereby demonstrating a multiple anti-tumor mechanism. Ultimately, KPKQ achieved a 90.7 % tumor-inhibitory rate through in vivo PDT. Our findings may provide a promising framework for the discovery of novel tricyclic carbazole photosensitizers with high PDT efficacy.

The application of photodynamic therapy in recurrent genital herpes

BACKGROUND

Frequently, recurrence of genital herpes imposes significant physical and psychological burdens on patients, and existing treatments are often ineffective in preventing recurrence. Previous studies have indicated that photodynamic therapy (PDT) showed promising outcomes in the treatment of labial herpes simplex virus (HSV) infections; however, its efficacy for genital herpes remained unclear.

METHOD

The study screened patients with genital herpes at Daping Hospital from July 2020 to May 2024. Patients were divided into two groups based on whether they received PDT treatment. Over a one-year follow-up period, patients' healing time and recurrence rates were compared between the two groups. The cumulative incidence of recurrence and restricted mean survival time (RMST) were used to assess outcomes. Propensity score matching (PSM) was employed to minimize bias.

RESULT

A total of 41 patients enrolled in our study, with 8 (19.5 %) received PDT. The non-PDT group exhibited a slower skin lesion healing time, averaging at 7.2 days compared to 5.4 days in the PDT group. A significant difference was observed in the cumulative incidence of recurrence between the PDT and non-PDT groups (37.5 % versus 71.4 %) after PSM. The RMST in the PDT group was 9.94 days, compared to 5.13 days in the non-PDT group before PSM, and 4.14 after PSM.

CONCLUSION

Our study demonstrated that the PDT effectively reduced lesion recovery time and delayed recurrences of genital herpes. We recommend considering PDT as a potential treatment option for patients with recurrent genital herpes.

Systemic Effects of Photoactivated 5,10,15,20-tetrakis(N-methylpyridinium-3-yl) Porphyrin on Healthy Drosophila melanogaster

Porphyrins are frequently employed in photodynamic therapy (PDT), a non-invasive technique primarily utilized to treat subcutaneous cancers, as photosensitizing agents (PAs). The development of a new PA with improved tissue selectivity and efficacy is crucial for expanding the application of PDT for the management of diverse cancers. We investigated the systemic effects of 5,10,15,20-tetrakis(N-methylpyridinium-3-yl)-porphyrin (TMPyP3) using Drosophila melanogaster adult males. We established the oral administration schedule and demonstrated that TMPyP3 was absorbed and stored higher in neuronal than in non-neuronal extracts. Twenty-four hours after oral TMPyP3 photoactivation, the quantity of hydrogen peroxide (H2O2) increased, but exclusively in the head extracts. Regardless of photoactivation, TMPyP3 resulted in a reduced concentration of H2O2 after 7 days, and this was linked with a decreased capacity to climb, as indicated by negative geotaxis. The findings imply that systemic TMPyP3 therapy may disrupt redox regulation, impairing cellular signaling and behavioral outcomes in the process. To determine the disruptive effect of porphyrins on redox homeostasis, its duration, and the mechanistic variations in retention across various tissues, more research is required.

Lipid-Centric Approaches in Combating Infectious Diseases: Antibacterials, Antifungals and Antivirals with Lipid-Associated Mechanisms of Action

One of the global challenges of the 21st century is the increase in mortality from infectious diseases against the backdrop of the spread of antibiotic-resistant pathogenic microorganisms. In this regard, it is worth targeting antibacterials towards the membranes of pathogens that are quite conservative and not amenable to elimination. This review is an attempt to critically analyze the possibilities of targeting antimicrobial agents towards enzymes involved in pathogen lipid biosynthesis or towards bacterial, fungal, and viral lipid membranes, to increase the permeability via pore formation and to modulate the membranes' properties in a manner that makes them incompatible with the pathogen's life cycle. This review discusses the advantages and disadvantages of each approach in the search for highly effective but nontoxic antimicrobial agents. Examples of compounds with a proven molecular mechanism of action are presented, and the types of the most promising pharmacophores for further research and the improvement of the characteristics of antibiotics are discussed. The strategies that pathogens use for survival in terms of modulating the lipid composition and physical properties of the membrane, achieving a balance between resistance to antibiotics and the ability to facilitate all necessary transport and signaling processes, are also considered.

Alkyl Derivatives of Perylene Photosensitizing Antivirals: Towards Understanding the Influence of Lipophilicity

Amphipathic perylene derivatives are broad-spectrum antivirals against enveloped viruses that act as fusion inhibitors in a light-dependent manner. The compounds target the lipid bilayer of the viral envelope using the lipophilic perylene moiety and photogenerating singlet oxygen, thereby causing damage to unsaturated lipids. Previous studies show that variation of the polar part of the molecule is important for antiviral activity. Here, we report modification of the lipophilic part of the molecule, perylene, by the introduction of 4-, 8-, and 12-carbon alkyls into position 9(10) of the perylene residue. Using Friedel-Crafts acylation and Wolff-Kishner reduction, three 3-acetyl-9(10)-alkylperylenes were synthesized from perylene and used to prepare 9 nucleoside and 12 non-nucleoside amphipathic derivatives. These compounds were characterized as fluorophores and singlet oxygen generators, as well as tested as antivirals against herpes virus-1 (HSV-1) and vesicular stomatitis virus (VSV), both known for causing superficial skin/mucosa lesions and thus serving as suitable candidates for photodynamic therapy. The results suggest that derivatives with a short alkyl chain (butyl) have strong antiviral activity, whereas the introduction of longer alkyl substituents (n = 8 and 12) to the perylenyethynyl scaffold results in a dramatic reduction of antiviral activity. This phenomenon is likely attributable to the increased lipophilicity of the compounds and their ability to form insoluble aggregates. Moreover, molecular dynamic studies revealed that alkylated perylene derivatives are predominately located closer to the middle of the bilayer compared to non-alkylated derivatives. The predicted probability of superficial positioning correlated with antiviral activity, suggesting that singlet oxygen generation is achieved in the subsurface layer of the membrane, where the perylene group is more accessible to dissolved oxygen.