In vitro studies of the antiherpetic effect of photodynamic therapy

Protoporphyrin IX loaded polysilsesquioxane nanoparticles: photostability and cellular response to photodynamic therapy

Photodynamic therapy (PDT) is a non-invasive therapeutic approach used for the treatment of cancer. Several nanoparticulate systems have been currently developed to enhance the phototherapeutic effect associated with PDT. In particular, polysilsesquioxane (PSilQ) nanoparticles are a promising hybrid platform with numerous advantages to be used as a delivery system. PSilQ nanoparticles were prepared to efficiently carry protoporphyrin IX (PpIX) as a PS agent to treat triplet-negative breast cancer. In this report, the photostability performance of this PSilQ platform was evaluated, as well as its PDT effect on breast cancer (MCF-7) and human dermal fibroblasts, neonatal (HDFn) cell lines. The fluorescence life-time results demonstrated that the PpIX molecules are aggregated inside the PSilQ framework. Nevertheless, similar PDT outcome was obtained against MCF-7 cells as compared to PpIX molecules. Moreover, the PSilQ platform reduced the dark toxicity associated with PpIX in HDFn cells. These relevant features make PSilQ nanoparticles an interesting platform for PDT of cancer.

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.

Aspects of Antiviral Strategies Based on Different Phototherapy Approaches: Hit by the Light

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which caused the COVID-19 pandemic spreading around the world from late 2019, served as a ruthless reminder of the threat viruses pose to global public health. The synthesis of new antiviral drugs, as well as repurposing existing products, is a long-term ongoing process which has challenged the scientific community. One solution could be an effective, accessible, and rapidly available antiviral treatment based on phototherapy (PT). PT has been used to treat several diseases, and relies on the absorption of light by endogenous molecules or exogenous photosensitizers (PS). PT has often been used in cancer treatment and prophylaxis, and as a complement to established chemotherapy and immunotherapy in combined therapeutic strategy. Besides significant applications in anticancer treatment, studies have demonstrated the beneficial impact of PT on respiratory, systemic, emerging, and oncogenic viral infections. The aim of this review was to highlight the potential of PT to combat viral infections by summarizing current progress in photodynamic, photothermal, and photoacoustic approaches. Attention is drawn to the virucidal effect of PT on systemic viruses such as the human immunodeficiency virus and human herpes viruses, including the causative agent of Kaposi sarcoma, human herpes virus (HHV8). PT has good potential for disinfection in anti-norovirus research and against pandemic viruses like SARS-CoV-2.

Photodynamic viral inactivation: Recent advances and potential applications

Antibiotic-resistant bacteria, which are growing at a frightening rate worldwide, has put the world on a long-standing alert. The COVID-19 health crisis reinforced the pressing need to address a fast-developing pandemic. To mitigate these health emergencies and prevent economic collapse, cheap, practical, and easily applicable infection control techniques are essential worldwide. Application of light in the form of photodynamic action on microorganisms and viruses has been growing and is now successfully applied in several areas. The efficacy of this approach has been demonstrated in the fight against viruses, prompting additional efforts to advance the technique, including safety use protocols. In particular, its application to suppress respiratory tract infections and to provide decontamination of fluids, such as blood plasma and others, can become an inexpensive alternative strategy in the fight against viral and bacterial infections. Diverse early treatment methods based on photodynamic action enable an accelerated response to emerging threats prior to the availability of preventative drugs. In this review, we evaluate a vast number of photodynamic demonstrations and first-principle proofs carried out on viral control, revealing its potential and encouraging its rapid development toward safe clinical practice. This review highlights the main research trends and, as a futuristic exercise, anticipates potential situations where photodynamic treatment can provide a readily available solution.

A systematic review of photodynamic therapy as an antiviral treatment: Potential guidance for dealing with SARS-CoV-2

BACKGROUND

SARS-CoV-2, which causes the coronavirus disease (COVID-19), presents high rates of morbidity and mortality around the world. The search to eliminate SARS-CoV-2 is ongoing and urgent. This systematic review seeks to assess whether photodynamic therapy (PDT) could be effective in SARS-CoV-2 inactivation.

METHODS

The focus question was: Can photodynamic therapy be used as potential guidance for dealing with SARS-CoV-2?". A literature search, according to PRISMA statements, was conducted in the electronic databases PubMed, EMBASE, SCOPUS, Web of Science, LILACS, and Google Scholar. Studies published from January 2004 to June 2020 were analyzed. In vitro and in vivo studies were included that evaluated the effect of PDT mediated by several photosensitizers on RNA and DNA enveloped and non-enveloped viruses.

RESULTS

From 27 selected manuscripts, 26 publications used in vitro studies, 24 were exclusively in vitro, and two had in vitro/in vivo parts. Only one analyzed publication was exclusively in vivo. Meta-analysis studies were unfeasible due to heterogeneity of the data. The risk of bias was analyzed in all studies.

CONCLUSION

The in vitro and in vivo studies selected in this systematic review indicated that PDT is capable of photoinactivating enveloped and non-enveloped DNA and RNA viruses, suggesting that PDT can potentially photoinactivate SARS-CoV-2.

Treatment of recurrent herpes of the lower lip skin region with photodynamic therapy and photobiomodulation: case report

The aim of the present study is to describe a case report on the treatment of recurrent herpes using Photodynamic therapy (PDT) and Photobiomodulation as the treatments of choice. A 21-year-old white man checked in in the clinic for evaluation of vesicles arranged in the lower lip skin region. The clinical diagnosis was recurrent herpes and, for treatment, PDT was chosen, using 0.1% methylene blue as a photosensitizer and a pre-irradiation time of five minutes. The Therapy XT laser was used, with a wavelength of 660 nm, power of 100 mW, in a spot area of 0.028 cm², using 4 J energy per point, having been applied on 4 points, one in the center of the lesion and three on its laterals, so that it involved the entire extension of the lesion, totaling 16 J. After 24 hours after the application of the PDT, the patient returned for photobiomodulation with a low-power laser with a wavelength of 660 nm, power of 100 mW, using energy of 1 J per point, for 10 s, being applied on 4 points, totaling 4 J. It was possible to observe complete healing after 10 days of treatment, and the patient remains in follow-up for eight months without any recurrences.

Trends and targets in antiviral phototherapy

Photodynamic therapy (PDT) is a well-established treatment option in the treatment of certain cancerous and pre-cancerous lesions. Though best-known for its application in tumor therapy, historically the photodynamic effect was first demonstrated against bacteria at the beginning of the 20^th century. Today, in light of spreading antibiotic resistance and the rise of new infections, this photodynamic inactivation (PDI) of microbes, such as bacteria, fungi, and viruses, is gaining considerable attention. This review focuses on the PDI of viruses as an alternative treatment in antiviral therapy, but also as a means of viral decontamination, covering mainly the literature of the last decade. The PDI of viruses shares the general action mechanism of photodynamic applications: the irradiation of a dye with light and the subsequent generation of reactive oxygen species (ROS) which are the effective phototoxic agents damaging virus targets by reacting with viral nucleic acids, lipids and proteins. Interestingly, a light-independent antiviral activity has also been found for some of these dyes. This review covers the compound classes employed in the PDI of viruses and their various areas of use. In the medical area, currently two fields stand out in which the PDI of viruses has found broader application: the purification of blood products and the treatment of human papilloma virus manifestations. However, the PDI of viruses has also found interest in such diverse areas as water and surface decontamination, and biosafety.

Effect of photodynamic therapy by 810 and 940 nm diode laser on Herpes Simplex Virus 1: An in vitro study

INTRODUCTION

Herpes simplex virus (HSV) is among the most common viruses in humans. HSV1 is often responsible for oral and perioral herpetic lesions. Photodynamic therapy (PDT) is a novel antimicrobial modality that involves the use of laser and a photosensitizer with a specific wavelength. This study aimed to assess and compare the effect of PDT with 810 and 940 nm diode laser and indocyanine green (ICG) photosensitizer on HSV1.

METHODS

In this in vitro study, HSV1 isolated from herpes labialis and there were 6 experimental groups.The irradiation parameters were the same for all groups. Number of remaining viruses per milliliter in each group was determined using real-time polymerase chain reaction (PCR) and statistically analyzed by ANOVA.

RESULTS

The virus count in all groups significantly decreased compared to the control group (P < 0.05) except in group ICG- without irradiation (P > 0.05). Comparison of groups 810- and 940- (use of each laser alone) with groups 810+ and 940+ (use of each laser plus ICG) revealed that reduction in virus count in groups 810+ and 940+ was significantly greater than that in groups 810- and 940-.

CONCLUSION

810 nm diode laser irradiation and ICG causes the greatest reduction in number of HSV1 compared to all the other groups. ICG without laser irradiation has not significant efficacy on reduction of virus count.

Use of electroanalgesia and laser therapies as alternatives to opioids for acute and chronic pain management

The use of opioid analgesics for postoperative pain management has contributed to the global opioid epidemic. It was recently reported that prescription opioid analgesic use often continued after major joint replacement surgery even though patients were no longer experiencing joint pain. The use of epidural local analgesia for perioperative pain management was not found to be protective against persistent opioid use in a large cohort of opioid-naïve patients undergoing abdominal surgery. In a retrospective study involving over 390,000 outpatients more than 66 years of age who underwent minor ambulatory surgery procedures, patients receiving a prescription opioid analgesic within 7 days of discharge were 44% more likely to continue using opioids 1 year after surgery. In a review of 11 million patients undergoing elective surgery from 2002 to 2011, both opioid overdoses and opioid dependence were found to be increasing over time. Opioid-dependent surgical patients were more likely to experience postoperative pulmonary complications, require longer hospital stays, and increase costs to the health-care system. The Centers for Disease Control and Prevention emphasized the importance of finding alternatives to opioid medication for treating pain. In the new clinical practice guidelines for back pain, the authors endorsed the use of non-pharmacologic therapies. However, one of the more widely used non-pharmacologic treatments for chronic pain (namely radiofrequency ablation therapy) was recently reported to have no clinical benefit. Therefore, this clinical commentary will review evidence in the peer-reviewed literature supporting the use of electroanalgesia and laser therapies for treating acute pain, cervical (neck) pain, low back pain, persistent post-surgical pain after spine surgery (“failed back syndrome”), major joint replacements, and abdominal surgery as well as other common chronic pain syndromes (for example, myofascial pain, peripheral neuropathic pain, fibromyalgia, degenerative joint disease/osteoarthritis, and migraine headaches).