The history of photodetection and photodynamic therapy

Advances in nanotechnology-assisted photodynamic therapy for neurological disorders: a comprehensive review

Neurological disorders such as neurodegenerative diseases and nervous system tumours affect more than one billion people throughout the globe. The physiological sensitivity of the nervous tissue limits the application of invasive therapies and leads to poor treatment and prognosis. One promising solution that has generated attention is Photodynamic therapy (PDT), which can potentially revolutionise the treatment landscape for neurological disorders. PDT attracted substantial recognition for anticancer efficacy and drug conjugation for targeted drug delivery. This review thoroughly explained the basic principles of PDT, scientific interventions and advances in PDT, and their complicated mechanism in treating brain-related pathologies. Furthermore, the merits and demerits of PDT in the context of neurological disorders offer a well-rounded perspective on its feasibility and challenges. In conclusion, this review encapsulates the significant potential of PDT in transforming the treatment landscape for neurological disorders, emphasising its role as a non-invasive, targeted therapeutic approach with multifaceted applications.

Metabolic engineering of Saccharomyces cerevisiae for the biosynthesis of a fungal pigment from the phytopathogenic fungus Cladosporium phlei

BACKGROUND

Cladosporium phlei is a phytopathogenic fungus that produces a pigment called phleichrome. This fungal perylenequinone plays an important role in the production of a photosensitizer that is a necessary component of photodynamic therapy. We applied synthetic biology to produce phleichrome using Saccharomyces cerevisiae.

RESULTS

The gene Cppks1, which encodes a non-reducing polyketide synthase (NR-PKS) responsible for the biosynthesis of phleichrome in C. phlei, was cloned into a yeast episomal vector and used to transform S. cerevisiae. In addition, a gene encoding a phosphopantetheinyl transferase (PPTase) of Aspergillus nidulans was cloned into a yeast integrative vector and also introduced into S. cerevisiae for the enzymatic activation of the protein product of Cppks1. Co-transformed yeasts were screened on a leucine/uracil-deficient selective medium and the presence of both integrative as well as episomal recombinant plasmids in the yeast were confirmed by colony PCR. The episomal vector for Cppks1 expression was so dramatically unstable during cultivation that most cells lost their episomal vector rapidly in nonselective media. This loss was also observed to a less degree in selective media. This data strongly suggests that the presence of the Cppks1 gene exerts a significant detrimental effect on the growth of transformed yeast cells and that selection pressure is required to maintain the Cppks1-expressing vector. The co-transformants on the selective medium showed the distinctive changes in pigmentation after a period of prolonged cultivation at 20 °C and 25 °C, but not at 30 °C. Furthermore, thin layer chromatography (TLC) revealed the presence of a spot corresponding with the purified phleichrome in the extract from the cells of the co-transformants. Liquid chromatography (LC/MS/MS) verified that the newly expressed pigment was indeed phleichrome.

CONCLUSION

Our results indicate that metabolic engineering by multiple gene expression is possible and capable of producing fungal pigment phleichrome in S. cerevisiae. This result adds to our understanding of the characteristics of fungal PKS genes, which exhibit complex structures and diverse biological activities.

Gold nanoparticles-mediated photothermal and photodynamic therapies for cancer

Cancer remains one of the major causes of death globally, with one out of every six deaths attributed to the disease. The impact of cancer is felt on psychological, physical, and financial levels, affecting individuals, communities, and healthcare institutions. Conventional cancer treatments have many challenges and inadequacies. Nanomedicine, however, presents a promising solution by not only overcoming these problems but also offering the advantage of combined therapy for treatment-resistant cancers. Nanoparticles specifically engineered for use in nanomedicine can be efficiently targeted to cancer cells through a combination of active and passive techniques, leading to superior tumor-specific accumulation, enhanced drug availability, and reduced systemic toxicity. Among various nanoparticle formulations designed for cancer treatment, gold nanoparticles have gained prominence in the field of nanomedicine due to their photothermal, photodynamic, and immunologic effects without the need for photosensitizers or immunotherapeutic agents. To date, there is no comprehensive literature review that focuses on the photothermal, photodynamic, and immunologic effects of gold nanoparticles. In this review, significant attention has been devoted to examining the parameters pertaining to the structure of gold nanoparticles and laser characteristics, which play a crucial role in influencing the efficacy of photothermal therapy (PTT) and photodynamic therapy (PDT). Moreover, this article provides insights into the success of PTT and PDT mediated by gold nanoparticles in primary cancer treatment, as well as the immunological effects of PTT and PDT on metastasis and recurrence, providing a promising strategy for cancer therapy. In summary, gold nanoparticles, with their unique properties, have the potential for clinical application in various cancer therapies, including the treatment of primary cancer, recurrence and metastasis.

Research progress in photodynamic therapy for Helicobacter pylori infection

Helicobacter pylori (H. pylori) is a pathogenic microorganism that colonizes the human gastric mucosa and can lead to various gastric disorders, including gastritis, gastric ulcers, and gastric cancer. However, the increasing prevalence of antibiotic resistance in H. pylori has prompted the search for alternative treatment options. Photodynamic therapy has emerged as a potential alternative therapy, thus offering the advantage of avoiding some of the side effects associated with antibiotics and effectively targeting drug-resistant strains. In the postantibiotic era, photodynamic therapy (PDT) has shown promise as a novel treatment for H. pylori infection. This review focused on elucidating the mechanism of photodynamic therapy in the treatment of H. pylori. Additionally, we present an overview of the current research on photodynamic therapy by examining both standalone photodynamic therapy and combination therapies for H. pylori infection treatment. Furthermore, the safety profile of photodynamic therapy was also evaluated. Finally, we discuss the challenges and prospects associated with this innovative technology, with an aim to provide new insights and methodologies for the treatment of H. pylori infection.

Clinical Practice of Photodynamic Therapy for Non-Small Cell Lung Cancer in Different Scenarios: Who Is the Better Candidate?

BACKGROUND

Photodynamic therapy (PDT) is a relatively safe and highly selectivity antitumor treatment, which might be increasingly used as a supplement to conventional therapies. A clinical overview and detailed comparison of how to select patients and lesions for PDT in different scenarios are urgently needed to provide a basis for clinical treatment.

SUMMARY

This review demonstrates the highlights and obstacles of applying PDT for lung cancer and underlines points worth considering when planning to initiate PDT. The aim was to make out the appropriate selection and help PDT develop efficacy and precision through a better understanding of its clinical use.

KEY MESSAGES

Increasing evidence supports the feasibility and safety of PDT in the treatment of non-small cell lung cancer. It is important to recognize the factors that influence the efficacy of PDT to develop individualized management strategies and implement well-designed procedures. These important issues should be worth considering in the present and further research.

Current Advances in Photodynamic Therapy (PDT) and the Future Potential of PDT-Combinatorial Cancer Therapies

Photodynamic therapy (PDT) is a two-stage treatment that implies the use of light energy, oxygen, and light-activated compounds (photosensitizers) to elicit cancerous and precancerous cell death after light activation (phototoxicity). The biophysical, bioengineering aspects and its combinations with other strategies are highlighted in this review, both conceptually and as they are currently applied clinically. We further explore the recent advancements of PDT with the use of nanotechnology, including quantum dots as innovative photosensitizers or energy donors as well as the combination of PDT with radiotherapy and immunotherapy as future promising cancer treatments. Finally, we emphasize the potential significance of organoids as physiologically relevant models for PDT.

Poly(Glutamic Acid)-Engineered Nanoplatforms for Enhanced Cancer Phototherapy

Phototherapies, including photothermal therapy and photodynamic therapy, have gained booming development over the past several decades for their attractive non-invasiveness nature, negligible adverse effects, minimal systemic toxicity, and high spatial selectivity. Phototherapy usually requires three components: light irradiation, photosensitizers, and molecular oxygen. Photosensitizers can convert light energy into heat or reactive oxygen species, which can be used in the tumor-killing process. The direct application of photosensitizers in tumor therapy is restricted by their poor water solubility, fast clearance, severe toxicity, and low cellular uptake. The encapsulation of photosensitizers into nanostructures is an attractive strategy to overcome these critical limitations. Poly(glutamic acid) (PGA) is a kind of poly(amino acid)s containing the repeating units of glutamic acid. PGA has superiority for cancer treatment because of its good biocompatibility, low immunogenicity, and modulated pH responsiveness. The hydrophilicity nature of PGA allows the physical entrapment of photosensitizers and anticancer drugs via the construction of amphiphilic polymers. Moreover, the pendent carboxyl groups of PGA enable chemical conjugation with therapeutic agents. In this mini-review, we highlight the stateof- the-art design and fabrication of PGA-based nanoplatforms for phototherapy. We also discuss the potential challenges and future perspectives of phototherapy, and clinical translation of PGA-based nanomedicines.

Recent Advances in the HPPH-Based Third-Generation Photodynamic Agents in Biomedical Applications

Photodynamic therapy has emerged as a recognized anti-tumor treatment involving three fundamental elements: photosensitizers, light, and reactive oxygen species. Enhancing the effectiveness of photosensitizers remains the primary avenue for improving the biological therapeutic outcomes of PDT. Through three generations of development, HPPH is a 2-(1-hexyloxyethyl)-2-devinyl derivative of pyropheophorbide-α, representing a second-generation photosensitizer already undergoing clinical trials for various tumors. The evolution toward third-generation photosensitizers based on HPPH involves structural modifications for multimodal applications and the combination of multifunctional compounds, leading to improved imaging localization and superior anti-tumor effects. While research into third-generation HPPH is beneficial for advancing PDT treatment, equal attention should also be directed toward the other two essential elements and personalized diagnosis and treatment methodologies.

Recent advances in fluorescence imaging-guided photothermal therapy and photodynamic therapy for cancer: From near-infrared-I to near-infrared-II

Phototherapy (including photothermal therapy, PTT; and photodynamic therapy, PDT) has been widely used for cancer treatment, but conventional PTT/PDT show limited therapeutic effects due to the lack of disease recognition ability. The integration of fluorescence imaging with PTT/PDT can reveal tumor locations in a real-time manner, holding great potential in early diagnosis and precision treatment of cancers. However, the traditional fluorescence imaging in the visible and near-infrared-I regions (VIS/NIR-I, 400-900 nm) might be interfered by the scattering and autofluorescence from tissues, leading to a low imaging resolution and high false positive rate. The deeper near-infrared-II (NIR-II, 1000-1700 nm) fluorescence imaging can address these interferences. Combining NIR-II fluorescence imaging with PTT/PDT can significantly improve the accuracy of tumor theranostics and minimize damages to normal tissues. This review summarized recent advances in tumor PTT/PDT and NIR-II fluorophores, especially discussed achievements, challenges and prospects around NIR-II fluorescence imaging-guided PTT/PDT for cancers.

Successful treatment of non-melanoma skin cancer in three patients with Xeroderma Pigmentosum by modified ALA-PDT

Xeroderma pigmentosum(XP) is a rare autosomal recessive genodermatosis. Individuals with XP are characterized by severe skin sensitivity to sunlight, and more susceptible to the development of skin malignancies in sun-exposed regions. We report the experience of modified 5-aminolaevulinic acid photodynamic therapy (M-PDT) in the treatment of three children with XP. They all developed multiple freckle-like hyperpigmented papules and plaques on the face from an early age. Multiple cutaneous squamous cell carcinoma (cSCC) and actinic keratosis (AK) were developed in case 1 and case 2, and basal cell carcinoma (BCC) was observed in case 3. Sanger sequencing of targeted gene identified that case 1 and case 3 carried compound heterozygous mutations, and case 2 carried a homozygous mutation in the XPC gene. After multiple courses of M-PDT, the lesions were removed with mild adverse reactions, nearly painless and satisfactory safety.

Advanced Light Source Technologies for Photodynamic Therapy of Skin Cancer Lesions

Photodynamic therapy (PDT) is an increasingly popular dermatological treatment not only used for life-threatening skin conditions and other tumors but also for cosmetic purposes. PDT has negligible effects on underlying functional structures, enabling tissue regeneration feasibility. PDT uses a photosensitizer (PS) and visible light to create cytotoxic reactive oxygen species, which can damage cellular organelles and trigger cell death. The foundations of modern photodynamic therapy began in the late 19th and early 20th centuries, and in recent times, it has gained more attention due to the development of new sources and PSs. This review focuses on the latest advancements in light technology for PDT in treating skin cancer lesions. It discusses recent research and developments in light-emitting technologies, their potential benefits and drawbacks, and their implications for clinical practice. Finally, this review summarizes key findings and discusses their implications for the use of PDT in skin cancer treatment, highlighting the limitations of current approaches and providing insights into future research directions to improve both the efficacy and safety of PDT. This review aims to provide a comprehensive understanding of PDT for skin cancer treatment, covering various aspects ranging from the underlying mechanisms to the latest technological advancements in the field.

Promising Highly Targeted Therapies for Cholangiocarcinoma: A Review and Future Perspectives

To overcome the poor prognosis of cholangiocarcinoma (CCA), highly targeted therapies, such as antibody-drug conjugates (ADCs), photodynamic therapy (PDT) with/without systemic chemotherapy, and experimental photoimmunotherapy (PIT), have been developed. Three preclinical trials have investigated the use of ADCs targeting specific antigens, namely HER2, MUC1, and glypican-1 (GPC1), for CCA. Trastuzumab emtansine demonstrated higher antiproliferative activity in CCA cells expressing higher levels of HER2. Similarly, "staphylococcal enterotoxin A-MUC1 antibody" and "anti-GPC1 antibody-monomethyl auristatin F" conjugates showed anticancer activity. PDT is effective in areas where appropriate photosensitizers and light coexist. Its mechanism involves photosensitizer excitation and subsequent reactive oxygen species production in cancer cells upon irradiation. Hematoporphyrin derivatives, temoporfin, phthalocyanine-4, talaporfin, and chlorine e6 derivatives have mainly been used clinically and preclinically in bile duct cancer. Currently, new forms of photosensitizers with nanotechnology and novel irradiation catheters are being developed. PIT is the most novel anti-cancer therapy developed in 2011 that selectively kills targeted cancer cells using a unique photosensitizer called "IR700" conjugated with an antibody specific for cancer cells. PIT is currently in the early stages of development for identifying appropriate CCA cell targets and irradiation devices. Future human and artificial intelligence collaboration has potential for overcoming challenges related to identifying universal CCA cell targets. This could pave the way for highly targeted therapies for CCA, such as ADC, PDT, and PIT.

Recent trends in macromolecule-conjugated hybrid quantum dots for cancer theranostic applications

Quantum dots (QDs) are small nanoparticles with semiconductor properties ranging from 2 to 10 nanometers comprising 10-50 atoms. The single wavelength excitation character of QDs makes it more significant, as it can excite multiple particles in a confined surface simultaneously by narrow emission. QDs are more photostable than traditional organic dyes; however, when injected into tissues, whole animals, or ionic solutions, there is a significant loss of fluorescence. HQD-based probes conjugated with cancer-specific ligands, antibodies, or peptides are used in clinical diagnosis. It is more precise and reliable than standard immunohistochemistry (IHC) at minimal protein expression levels. Advanced clinical studies use photodynamic therapy (PDT) with fluorescence imaging to effectively identify and treat cancer. Recent studies revealed that a combination of unique characteristics of QDs, including their fluorescence capacity and abnormal expression of miRNA in cancer cells, were used for the detection and monitoring progression of cancer. In this review, we have highlighted the unique properties of QDs and the theranostic behavior of various macromolecule-conjugated HQDs leading to cancer treatment.

Research development of porphyrin-based metal-organic frameworks: targeting modalities and cancer therapeutic applications

Porphyrins are naturally occurring organic molecules that have attracted widespread attention for their potential in the field of biomedical research. Porphyrin-based metal-organic frameworks (MOFs) that utilize porphyrin molecules as organic ligands have gained attention from researchers due to their excellent results as photosensitizers in tumor photodynamic therapy (PDT). Additionally, MOFs hold significant promise and potential for other tumor therapeutic approaches due to their tunable size and pore size, excellent porosity, and ultra-high specific surface area. Active delivery of nanomaterials via targeted molecules for tumor therapy has demonstrated greater accumulation, lower drug doses, higher therapeutic efficacy, and reduced side effects relative to passive targeting through the enhanced permeation and retention effect (EPR). This paper presents a comprehensive review of the targeting methods employed by porphyrin-based MOFs in tumor targeting therapy over the past few years. It further discusses the applications of porphyrin-based MOFs for targeted cancer therapy through various therapeutic methods. The objective of this paper is to provide a valuable reference and source of ideas for targeted therapy using porphyrin-based MOF materials and to inspire further exploration of their potential in the field of cancer therapy.

Antimicrobial photodynamic therapy for the treatment of oral mucositis - a comparative study

OBJECTIVES

The aim was to evaluate the effectiveness of the photobiomodulation associated to antimicrobial photodynamic therapy in the treatment of oral mucositis.

BACKGROUND

Oral Mucositis is a frequent complication of oral cavity and oropharynx cancer. Considering the OM aggravation by microorganisms contamination, disinfection provide by antimicrobial photodynamic therapy could be an effective approach.

MATERIAL AND METHODS

This comparative study included fourteen patients undergoing radiochemotherapy for oral cavity and oropharynx cancer treatment, who developed oral mucositis.

CONTROL GROUP

photobiomodulation. Intervention group: photobiomodulation and antimicrobial photodynamic therapy. The lesion size, duration, pain, and identification of microorganisms were evaluated.

RESULTS

The mean reduction in oral mucositis size in the intervention group was 0.70 cm² (±0.35) and 0.30 cm² (±1.10) for the control group. The mean duration of oral mucositis was 18.37 days (±12.12) for the intervention group and 23 days (±14.78) for the control group. The intervention group had a mean reduction of 3.40 points on the pain scale (±2.44), while the control group had 0.17 (±2.28). In the intervention group, the predominant isolated microbiota was featured as mixed culture (n=4/ 50%), followed of Gram Positive (n=3/ 37.50%), and Gram Negative (n=1/ 12.55%). In the control group, mixed culture was also more frequent (n=4 / 66%), followed by Gram Positive (n=2 /34%). Gram Negative was not predominantly isolated in the control group.

CONCLUSION

No statistical significance was found between PBM-T alone and PBM-T + PDT. However, the better outcomes reached by PBM-T + PDT group would suggest there could be a role for combined treatment in the management of OM lesions.

Design, synthesis, antitumor activity and ct-DNA binding study of photosensitive drugs based on porphyrin framework

Photodynamic therapy is a promising novel tumor treatment method. In this study, novel porphyrin-chrysin photosensitizer derivatives were synthesized. Most of the compounds showed antitumor activity against human cervical cancer HeLa cells and human lung cancer A549 cells, among which compound 4c had the best photodynamic therapy effect on HeLa cells and A549 cells, with IC₅₀ values of 6.26 μM and 23.37 μM, respectively. Free-base porphyrin-chrysin derivatives bind to DNA through surface self-stacking, and zinc metalloporphyrin-chrysin derivatives bind to ct-DNA through intercalation. Notably, the tightness of compound binding to ct-DNA was positively correlated with its antitumor activity. What's more, three-dimensional quantitative conformation studies have shown that increasing the positive charge of the porphyrin ring and introducing a strong electron-withdrawing group at the meso position of the porphyrin ring at the para-position of the benzene ring or reducing the space volume of the compound can enhance the antitumor activity.

Chlorin e6: A Promising Photosensitizer in Photo-Based Cancer Nanomedicine

Conventional cancer treatment modalities are often associated with major therapeutic limitations and severe side effects. Photodynamic therapy is a localized noninvasive mode of treatment that has given a different direction to cancer research due to its effectivity against a wide range of cancers and minimal side effects. A photosensitizer is the key component of photodynamic therapy (PDT) that generates cytotoxic reactive oxygen species to eradicate cancer cells. As the therapeutic effectivity of PDT greatly depends upon the photosensitizer, great efforts have been made to search for an ideal photosensitizer. Chlorin e6 is a FDA approved second generation photosensitizer that meets the desired clinical properties for PDT. It is known for its high reactive oxygen species (ROS) generation ability and anticancer potency against many types of cancer. Hydrophobicity is a major drawback of Ce6 that leads to its poor biodistribution and rapid clearance from the circulatory system. To overcome this drawback, researchers have designed and fabricated several types of nanosystems, which can enhance Ce6 solubility and thereby enhance its bioavailability. These nanosystems also improve tumor accumulation of Ce6 by selectively targeting the cancer cells through passive and active targeting. In addition, Ce6 has been employed in many combination therapies like chemo-photodynamic therapy, photoimmunotherapy, and combined photodynamic-photothermal therapy. A combination therapy is more curative than a single therapy due to the synergistic effects of individual therapies. Ce6-based nanosystems for combination therapies have shown excellent results in various studies and provide a promising platform for cancer treatment.

Recent Progress in Nanomaterial-Based Biosensors and Theranostic Nanomedicine for Bladder Cancer

Bladder cancer (BCa) is one of the most expensive and common malignancies in the urinary system due to its high progression and recurrence rate. Although there are various methods, including cystoscopy, biopsy, and cytology, that have become the standard diagnosis methods for BCa, their intrinsic invasive and inaccurate properties need to be overcome. The novel urine cancer biomarkers are assisted by nanomaterials-based biosensors, such as field-effect transistors (FETs) with high sensitivity and specificity, which may provide solutions to these problems. In addition, nanomaterials can be applied for the advancement of next-generation optical imaging techniques and the contrast agents of conventional techniques; for example, magnetic resonance imaging (MRI) for the diagnosis of BCa. Regarding BCa therapy, nanocarriers, including mucoadhesive nanoparticles and other polymeric nanoparticles, successfully overcome the disadvantages of conventional intravesical instillation and improve the efficacy and safety of intravesical chemotherapy for BCa. Aside from chemotherapy, nanomedicine-based novel therapies, including photodynamic therapy (PDT), photothermal therapy (PTT), chemodynamic therapy (CDT), sonodynamic therapy (SDT), and combination therapy, have afforded us new ways to provide BC therapy and hope, which can be translated into the clinic. In addition, nanomotors and the nanomaterials-based solid tumor disassociation strategy provide new ideas for future research. Here, the advances in BCa diagnosis and therapy mentioned above are reviewed in this paper.

Reaction mechanism of nanomedicine based on porphyrin skeleton and its application prospects

Research on porphyrin-based photosensitizing drugs is becoming increasingly popular. They possess unique diagnostic capabilities and therapeutic effects that have gained wide recognition in oncology drug development. In recent years, the rapid growth of nanotechnology has brought great hope for nanopharmaceutical formulations. By combining porphyrins with various nanomaterials, people have improved the properties of porphyrin compounds, making drug delivery easier. Porphyrin-based nanoparticles can enhance the effect of photodynamic therapy for cancer treatment, providing opportunities for achieving complex targeting strategies and versatility with promising applications in drug carriers, tumor imaging, and treatment. This paper reviews recent porphyrin nanodrugs, including inorganic-organic hybrid nanoparticles, nanomicelles, self-assembled nanoparticles, and combination therapeutic nanodrugs, and their actions and effects on cancer cells when performing photodynamic therapy. It also discusses the drawbacks as well as the prospects for development.

Long-term efficacy of percutaneous transhepatic cholangioscopy-guided photodynamic therapy for postoperative recurrent extrahepatic cholangiocarcinoma

BACKGROUND

Cholangiocarcinoma recurs frequently following excision surgery and is usually inoperable, while radiotherapy, chemotherapy, and immunotherapy are of limited benefit. As palliative care, percutaneous transhepatic cholangial drainage (PTCD) can relieve biliary obstruction, prevent jaundice, and maintain quality of life (QOL), but does not improve overall survival. In contrast, photodynamic therapy (PDT) has been demonstrated to prolong the survival of inoperable cancer patients.

OBJECTIVE

This study evaluated the clinical efficacy of percutaneous transhepatic cholangioscopy (PTCS)-guided PDT following PTCD versus PTCD alone for recurrent inoperable cholangiocarcinoma.

METHODS

The case files of 39 patients with postoperative recurrence were retrospectively analyzed, including 18 receiving PTCS-guided PDT (PTCS-PDT group) and 21 receiving PTCD only as a control (PTCD group). Survival time was compared by Kaplan-Meier analysis and log-rank test, and QOL by the Functional Assessment of Cancer Therapy-Hepatobiliary (FACT-HEP) questionnaire. Clinicodemographic factors, including serum bilirubin and adverse reaction rates, were compared by Student's t-test or Fisher's exact test. The maximum follow-up period was 71 months.

RESULTS

Median survival time was significantly longer in the PTCS-PDT group than the PTCD group (23 months vs. 10 months, P = 0.00001). At 6 and 12 months post-treatment, total FACT-HEP score was lower in the PTCS-PDT group (P < 0.05), indicating improved QOL. There was no significant difference in total adverse events incidence between groups (19 [51.4%] vs. 15 [71.4%]; P = 0.131).

CONCLUSION

PTCS-guided PDT can prolong survival and improve the QOL of patients with postoperative cholangiocarcinoma recurrence without increasing complications.

SIGNIFICANT AND/OR NEW FINDINGS

Compared to PTCD alone, PTCS-guided PDT significantly prolonged the survival time of patients with postoperative recurrent extrahepatic cholangiocarcinoma. Photodynamic therapy also improved patient quality of life by facilitating timely removal of the PTCD drainage tube. PTCS-guided PDT did not increase surgery-related complications except for skin phototoxicity, which can be easy avoided and treated.

Photodynamic Therapy: A Prospective Therapeutic Approach for Viral Infections and Induced Neoplasia

The recent COVID-19 pandemic outbreak and arising complications during treatments have highlighted and demonstrated again the evolving ability of microorganisms, especially viral resistance to treatment as they develop into new and strong strains. The search for novel and effective treatments to counter the effects of ever-changing viruses is undergoing. Although it is an approved procedure for treating cancer, photodynamic therapy (PDT) was first used against bacteria and has now shown potential against viruses and certain induced diseases. PDT is a multi-stage process and uses photosensitizing molecules (PSs) that accumulate in diseased tissues and eradicates them after being light-activated in the presence of oxygen. In this review, studies describing viruses and their roles in disrupting cell regulation mechanisms and signaling pathways and facilitating tumorigenesis were described. With the development of innovative “or smart” PSs through the use of nanoparticles and two-photon excitation, among other strategies, PDT can boost immune responses, inactivate viral infections, and eradicate neoplastic cells. Visualization and monitoring of biological processes can be achieved in real-time with nanomedicines and better tissue penetration strategies. After photodynamic inactivation of viruses, signaling pathways seem to be restored but the underlying mechanisms are still to be elucidated. Light-mediated treatments are suitable to manage both oncogenic viral infections and induced neoplasia.

BODIPYs in PDT: A Journey through the Most Interesting Molecules Produced in the Last 10 Years

Over the past 30 years, photodynamic therapy (PDT) has shown great development. In the clinical setting the few approved molecules belong almost exclusively to the porphyrin family; but in the scientific field, in recent years many researchers have been interested in other families of photosensitizers, among which BODIPY has shown particular interest. BODIPY is the acronym for 4,4-difluoro-4-bora-3a, 4a-diaza-s-indacene, and is a family of molecules well-known for their properties in the field of imaging. In order for these molecules to be used in PDT, a structural modification is necessary which involves the introduction of heavy atoms, such as bromine and iodine, in the beta positions of the pyrrole ring; this change favors the intersystem crossing, and increases the ¹O₂ yield. This mini review focused on a series of structural changes made to BODIPYs to further increase ¹O₂ production and bioavailability by improving cell targeting or photoactivity efficiency.

Photoactive Herbal Compounds: A Green Approach to Photodynamic Therapy

Photodynamic therapy (PDT) is a minimally invasive, alternative, and promising treatment for various diseases, including cancer, actinic keratosis, Bowen’s disease, macular degeneration, and atherosclerotic plaques. PDT involves three different components, photosensitizers (PS), molecular oxygen, and light. The photoactivation of administered PSs using a specific wavelength of light in the presence of molecular oxygen leads to the generation of reactive oxygen species that leads to tumour cell death. Photosensitizing potentials of many commercially available compounds have been reported earlier. However, the possibilities of PDT using herbal medicines, which contain many photosensitizing phytochemicals, are not much explored. Medicinal plants with complex phytochemical compound mixtures have the benefit over single compounds or molecules in the treatment of many diseases with the benefit of low or reduced toxic side effects. This review emphasizes the role of various herbal medicines either alone or in combination to enhance the therapeutic outcome of photodynamic therapy.

Recent advances in metal-organic frameworks and their composites for the phototherapy of skin wounds

Wound healing is a complex process that greatly affects the normal physiological activities of genes, proteins, signaling pathways, tissues, and organs. Bacterial infection could easily lead to serious tissue damage during wound healing, thus countering wound infections becomes a major challenge for clinicians and nursing professionals. At present, the exploration of highly effective, low toxicity and environment friendly methods for wound healing is attracting considerable interest all over the world. Recently, metal-organic frameworks (MOFs) have presented great potential for treating wound infections due to their unique characteristics of diversified functionality, large specific surface area, and high biocompatibility. These properties endow MOFs/MOF-based composites with an outstanding anti-wound infection effect, which is mainly attributed to the continuously released active components and the exerted catalytic activity with the assistance of phototherapy. In this review, the current progress of MOFs/MOF-based composites for the phototherapy of skin wounds is presented. Firstly, we illustrate the pathophysiological mechanisms, principles of phototherapy and the conventional methods for wound healing. Then, the structures and characteristics of MOFs are systematically summarized. Moreover, the review highlights the recent advances in the application of phototherapy for wound healing (including photodynamic therapy, photothermal therapy, and synergistic therapy) based on various MOFs/MOF-based composites. Finally, the challenges and perspectives are provided for the further development of MOF-based materials for medical application.

Theoretical investigation of [Ru(bpy)2(HAT)]2+ (HAT = 1,4,5,8,9,12-hexaazatriphenylene; bpy = 2,2'-bipyridine): Photophysics and reactions in excited state

In this article, Density Functional Theory based calculations, including dispersion corrections, PBE0(D3BJ)/Def2-TZVP(-f), were performed to elucidate the photophysics of the [Ru(bpy)₂(HAT)]²⁺ complex in water. In addition, the thermodynamics of the charge and electron transfer excited state reactions of this complex with oxygen, nitric oxide and Guanosine-5'-monophosphate nucleotide (GMP) were investigated. The first singlet excite state, S₁, strongly couples with the second and third triplet excited states (T₂ and T₃) giving rise to a high intersystem crossing rate of 6.26 × 10¹¹ s^-1 which is ∼10⁶ greater than the fluorescence rate decay. The thermodynamics of the excited reactions revealed that all electron transfer reactions investigated are highly favorable, due mainly to the high stability of the triply charged radical cation ²PS^•3+ species formed after the electron has been transferred. Excited state electron transfer from the GMP nucleotide to the complex is also highly favorable (ΔG_sol = -92.6 kcal/mol), showing that this complex can be involved in the photooxidation of DNA, in line with experimental findings. Therefore, the calculations allow to conclude that the [Ru(bpy)₂(HAT)]²⁺ complex can act in Photodynamic therapy through both mechanisms type I and II, through electron transfer from and to the complex and triplet-triplet energy transfer, generating ROS, RNOS and through DNA photooxidation. In addition, the work also opens a perspective of using this complex for the in-situ generation of the singlet nitroxyl (¹NO^-) species, which can have important applications for the generation of HNO and may have, therefore, important impact for physiological studies involving HNO.

Biological Evaluation of Photodynamic Effect Mediated by Nanoparticles with Embedded Porphyrin Photosensitizer

Clinically approved photodynamic therapy (PDT) is a minimally invasive treatment procedure that uses three key components: photosensitization, a light source, and tissue oxygen. However, the photodynamic effect is limited by both the photophysical properties of photosensitizers as well as their low selectivity, leading to damage to adjacent normal tissue and/or inadequate biodistribution. Nanoparticles (NPs) represent a new option for PDT that can overcome most of the limitations of conventional photosensitizers and can also promote photosensitizer accumulation in target cells through enhanced permeation and retention effects. In this in vitro study, the photodynamic effect of TPP photosensitizers embedded in polystyrene nanoparticles was observed on the non-tumor NIH3T3 cell line and HeLa and G361 tumor cell lines. The efficacy was evaluated by viability assay, while reactive oxygen species production, changes in membrane mitochondrial potential, and morphological changes before and after treatment were imaged by atomic force microscopy. The tested nanoparticles with embedded TPP were found to become cytotoxic only after activation by blue light (414 nm) due to the production of reactive oxygen species. The photodynamic effect observed in this evaluation was significantly higher in both tumor lines than the effect observed in the non-tumor line, and the resulting phototoxicity depended on the concentration of photosensitizer and irradiation time.

Derivatization based on tetrazine scaffolds: synthesis of tetrazine derivatives and their biomedical applications

The recent advances in tetrazine scaffold-based derivatizations have been summarized. The advantages and limitations of derivatization methods and applications of the developed tetrazine derivatives in bioorthogonal chemistry have been highlighted.

Fototerapia – metoda wykorzystywana w leczeniu przewlekłych schorzeń dermatologicznych

Wykorzystanie energii świetlnej w terapii schorzeń o różnej etiologii towarzyszy człowiekowi od czasów starożytnych. Elementem decydującym o powodzeniu terapii jest dobranie odpowiedniej długości promieniowania (terapia NB-UVB, BB-UVB i UVA1) lub wystąpienie interakcji między substancją światłoczułą skumulowaną w zmienionej chorobowo tkance a zastosowanym promieniowaniem (terapia PUVA oraz terapia fotodynamiczna). Metody terapeutyczne wykorzystujące energię świetlną są klasyfikowane na podstawie wykorzystywanego zakresu promieniowania. Obecnie wyróżnia się fototerapię UV, wykorzystującą promieniowanie UVA lub UVB oraz terapię fotodynamiczną (PDT; photodynamic therapy), podczas której stosowane jest promieniowanie o długości fali 350-700 nm.

Fototerapia UV wykorzystywana jest do leczenia schorzeń dermatologicznych, takich jak łuszczyca, bielactwo oraz atopowe zapalenie skóry, ze względu na jej działanie immunosupresyjne i antyproliferacyjne. Jest dostępna w postaci terapii PUVA polegającej na wykorzystaniu synergicznego działania promieniowania ultrafioletowego (UVA) oraz związków o działaniu światłouczulającym (8-metoksypsolaren, 5-metoksypsolaren). Ponadto wyróżniono monoterapię promieniowaniem ultrafioletowym A1 (UVA1), szerokozakresowym UVB (BB-UVB) i wąskozakresowym UVB (NB-UVB). Terapia fotodynamiczna obok konwencjonalnych metod leczenia jest nowoczesną i nieinwazyjną alternatywą wykorzystywaną zarówno w diagnostyce, jak i terapii chorób o różnej etiologii. W 90% przypadków PDT jest stosowana w schorzeniach dermatologicznych, takich jak trądzik pospolity czy łuszczyca. Selektywna aktywność cytotoksyczna wykazywana w kierunku złośliwych komórek nowotworowych powoduje, że terapia fotodynamiczna stosowana jest także z powodzeniem w leczeniu zmian onkologicznych. Duży postęp, przejawiający się zarówno w opracowywaniu innowacyjnych substancji światłoczułych, jak i nowych źródeł promieniowania, sprawia, iż zakres stosowalności terapii fotodynamicznej ciągle się poszerza.

W artykule przedstawiono obecnie dostępne formy fototerapii poprzez opis mechanizmu ich działania, zastosowania oraz możliwości powstania skutków niepożądanych.

How can biophotonics help dentistry to avoid or minimize cross infection by SARS-CoV-2?

Biophotonics is defined as the combination of biology and photonics (the physical science of the light). It is a general term for all techniques that deal with the interaction between biological tissues/cells and photons (light). Biophotonics offers a great variety of techniques that can facilitate the early detection of diseases and promote innovative theragnostic approaches. As the COVID-19 infection can be transmitted due to the face-to-face communication, droplets and aerosol inhalation and the exposure to saliva, blood, and other body fluids, as well as the handling of sharp instruments, dental practices are at increased risk of infection. In this paper, a literature review was performed to explore the application of Biophotonics approaches in Dentistry focusing on the COVID-19 pandemic and how they can contribute to avoid or minimize the risks of infection in a dental setting. For this, search-related papers were retrieved from PubMED, Scielo, Google Schoolar, and American Dental Association and Centers for Disease Control and Prevention databases. The body of evidence currently available showed that Biophotonics approaches can reduce microorganism load, decontaminate surfaces, air, tissues, and minimize the generation of aerosol and virus spreading by minimally invasive, time-saving, and alternative techniques in general. However, each clinical situation must be individually evaluated regarding the benefits and drawbacks of these approaches, but always pursuing less-invasive and less aerosol-generating procedures, especially during the COVID-19 pandemic.

Antimicrobial Effect of Phytochemicals from Edible Plants

Current strategies of combating bacterial infections are limited and involve the use of antibiotics and preservatives. Each of these agents has generally inadequate efficacy and a number of serious adverse effects. Thus, there is an urgent need for new antimicrobial drugs and food preservatives with higher efficacy and lower toxicity. Edible plants have been used in medicine since ancient times and are well known for their successful antimicrobial activity. Often photosensitizers are present in many edible plants; they could be a promising source for a new generation of drugs and food preservatives. The use of photodynamic therapy allows enhancement of antimicrobial properties in plant photosensitizers. The purpose of this review is to present the verified data on the antimicrobial activities of photodynamic phytochemicals in edible species of the world’s flora, including the various mechanisms of their actions.

Enzyme-Responsive Materials as Carriers for Improving Photodynamic Therapy

Photodynamic therapy (PDT) is a mini-invasive therapy on malignancies via reactive oxygen species (ROS) induced by photosenitizer (PS) upon light irradiation. However, poor target of PS to tumor limits the clinical application of PDT. Compared with normal tissues, tumor tissues have a unique enzymatic environment. The unique enzymatic environment in tumor tissues has been widely used as a target for developing smart materials to improve the targetability of drugs to tumor. Enzyme-responsive materials (ERM) as a smart material can respond to the enzymes in tumor tissues to specifically deliver drugs. In PDT, ERM was designed to react with the enzymes highly expressed in tumor tissues to deliver PS in the target site to prevent therapeutic effects and avoid its side-effects. In the present paper, we will review the application of ERM in PDT and discuss the challenges of ERM as carriers to deliver PS for further boosting the development of PDT in the management of malignancies.

Laser vaccine adjuvants: Light-augmented immune responses

Adjuvants are essential for ensuring the efficacy of modern vaccines. Considering frequent local and systemic adverse reactions, research into the development of safer and more effective adjuvants is being actively conducted. In recent years, the novel concept of laser vaccine adjuvants, which use the physical energy of light, has been developed. For long, light has been known to affect the physiological functions in living organisms. Since the development of lasers as stable light sources, laser adjuvants have evolved explosively in multiple ways over recent decades. Future laser adjuvants would have the potential not only to enhance the efficacy of conventional vaccine preparations but also to salvage candidate vaccines abandoned during development because of insufficient immunogenicity or owing to their inability to be combined with conventional adjuvants. Furthermore, the safety and efficacy of non-invasive laser adjuvants make them advantageous for vaccine dose sparing, which would be favorable for the timely and equitable global distribution of vaccines. In this review, we first describe the basics of light-tissue interactions, and then summarize the classification of lasers, the history of laser adjuvants, and the mechanisms by which different lasers elicit an immune response.

Betulinic acid and its spray dried microparticle formulation: In vitro PDT effect against ovarian carcinoma cell line and in vivo plasma and tumor disposition

The race against ovarian cancer continue to motivate the research worldwide. It is known that many antitumor drugs have limited penetration into solid tumor tissues due to its microenvironment, thus contributing to their low efficacy. Therapeutic modalities have been exploited to elicit antitumor effects based on microenvironment of tumor, including Photodynamic therapy (PDT). Prospection of natural small molecules and nanotechnology are important tools in the development of new ways of obtaining photoactive compounds that are biocompatible. The Betulinic acid (BA) has shown potential biological effect as bioactive drug, but it has low water solubility. Thus, in the present study, owing to the poor solubility of the BA, its free form (BAF) was compared to a spray dried microparticle betulinic acid/HP-β-CD formulation (BAC) aiming to assess the BAF and BAC efficacy as a photosensitizer in PDT for application in ovarian cancer. BAF and BAC were submitted to assays in the presence of LED (λ = 420 nm) under different conditions (2.75 J/cm2, 5.5 J/cm2, and 11 J/cm2) and in absence of irradiation, after 5 min or 4 h of contact with ovarian carcinoma cells (A2780) or fibroblast murine cells (3T3). Furthermore, HPLC-MS/MS and MALDI-MSI methods were developed and validated in plasma and tumor of mice proving suitable for in vivo studies. The results found a greater photoinduced cytotoxic effect for the BAC at low concentration for A2780 when irradiated with LED with similar results for fluorescence microscopy. The results motivate us to continue the studies with the BA as a potential antitumor bioactive compound.

Recent Advances in Photodynamic Imaging and Therapy in Hepatobiliary Malignancies: Clinical and Experimental Aspects

The therapeutic and diagnostic modalities of light are well known, and derivative photodynamic reactions with photosensitizers (PSs), specific wavelengths of light exposure and the existence of tissue oxygen have been developed since the 20th century. Photodynamic therapy (PDT) is an effective local treatment for cancer-specific laser ablation in malignancies of some organs, including the bile duct. Although curability for extrahepatic cholangiocarcinoma is expected with surgery alone, patients with unresectable or remnant biliary cancer need other effective palliative therapies, including PDT. The effectiveness of PDT for cholangiocarcinoma has been reported experimentally or clinically, but it is not the standard option now due to problems with accompanied photosensitivity, limited access routes of irradiation, tumor hypoxia, etc. Novel derivative treatments such as photoimmunotherapy have not been applied in the field hepatobiliary system. Photodynamic diagnosis (PDD) has been more widely applied in the clinical diagnoses of liver malignancies or liver vascularization. At present, 5-aminolevulinic acid (ALA) and indocyanine green (ICG) dyes are mainly used as PSs in PDD, and ICG has been applied for detecting liver malignancies or vascularization. However, no ideal tools for combining both PDD and PDT for solid tumors, including hepatobiliary malignancies, have been clinically developed. To proceed with experimental and clinical trials, it is necessary to clarify the effective photosensitive drugs that are feasible for photochemical diagnosis and local treatment.

The Protective Effects of Vitamins A and E on Titanium Dioxide Nanoparticles (nTiO2)-Induced Oxidative Stress in the Spleen Tissues of Male Wistar Rats

Titanium dioxide nanoparticles (nTiO2) can accumulate in different tissues and damage them with oxidative stress induction. Different components with antioxidant capacity can protect the tissues. So in this study, the protective effects of vitamin A and E on the nTiO2-induced oxidative stress in rats' spleen tissues were examined. Thirty-six male Wistar rats were randomly divided into 6 groups: Control 1 (received water), nTiO2, nTiO2 + vitamin E, nTiO2 + vitamin A, nTiO2 + vitamin A and E, and Control 2 (received olive oil). To investigate the status of oxidative stress, total antioxidant capacity (TAC), total oxidant status (TOS), and lipid peroxidation (LPO) were determined in spleen tissue as well as the activities of antioxidant enzymes, including glutathione peroxidase (GPx) and superoxide dismutase (SOD). Also, the gene expression of GPx, SOD, and nuclear factor-E2-related factor-2 (Nrf-2) were determined by qRT-PCR. To evaluate the spleen histopathological changes, H&E staining was carried out. nTiO2 significantly increased TOS and LPO levels, whereas it decreased TAC level, GPx and SOD activities, and gene expression of GPx, SOD, and Nrf-2 in spleen tissues of rats compared with controls (p < 0.05). In vitamin-treated rats, the levels of TOS and LPO significantly decreased, and the level of TAC, the activities of GPx and SOD, and the gene expression of GPx, SOD, and Nrf-2 increased compared to nTiO2 group (p < 0.05). These parameters are maintained near to normal levels. Histological findings confirmed the protective effects of these vitamins on tissue damage caused by nTiO2. Vitamin A and E can protect the spleen tissues from nTiO2-induced oxidative stress.

Antimicrobial photodynamic therapeutic effects of cationic amino acid-porphyrin conjugate 4i on Porphyromonas gingivalis in vitro

BACKGROUND

Porphyromonas gingivalis (P. gingivalis) is considered to be among the principal pathogens in periodontal disease. The present study aimed to investigate the effect of antimicrobial photodynamic therapy (aPDT) mediated by cationic amino acid-porphyrin conjugate 4i on P. gingivalis METHODS: The uptake of 4i by P. gingivalis over different times of incubation was evaluated by optical density using a microplate reader. Laser radiation at λ=650nm-660nm with I =50 mW/cm² at doses of 0, 3.0, 6.0, 9.0, and 12 J/cm² was used for aPDT. A colony-counting method and confocal laser scanning microscopy (CLSM) were used to observe the neutralization of P. gingivalis. The fluorescent molecular probe 3'(p-hydroxyphenyl)-fluorescein and the reagent Singlet Oxygen Sensor Green were used to measure the quantities of •OH and ¹O₂ produced by 4i after irradiation with different light energies.

RESULTS

The 4i conjugate was absorbed gradually by P. gingivalis, reaching a maximum at 30 min. A clear cytotoxic effect on P. gingivalis was observed with aPDT using 62.5 µM 4i, with colony counts dropping by a factor of 3.35 log₁₀, indicating a sterilization rate of 99.95%. Light irradiation resulted principally in the production of • OHby 4i. A live/dead viability assay demonstrated substantial red fluorescence in P. gingivalis treated with aPDT.

CONCLUSIONS

The results suggest that 4i-aPDT caused substantial cytotoxicity in P. gingivalis.

Photodynamic Therapy: A Compendium of Latest Reviews

Photodynamic therapy (PDT) is a promising therapy against cancer. Even though it has been investigated for more than 100 years, scientific publications have grown exponentially in the last two decades. For this reason, we present a brief compendium of reviews of the last two decades classified under different topics, namely, overviews, reviews about specific cancers, and meta-analyses of photosensitisers, PDT mechanisms, dosimetry, and light sources. The key issues and main conclusions are summarized, including ways and means to improve therapy and outcomes. Due to the broad scope of this work and it being the first time that a compendium of the latest reviews has been performed for PDT, it may be of interest to a wide audience.

Physical Medicine and Rehabilitation: From the Birth of a Specialty to Its Recognition

Physical Medicine and Rehabilitation (PMR) was subordinate to different specialties. Currently, it is recognized as essential to improving healthcare. How did it originate and which events impacted it? Different events have impacted the development of PMR including war, epidemic, sport, natural disasters, and the demographic and sociocultural characteristics of each country. At present, PMR is experiencing some difficulties throughout the world; we present proposals to improve its position to bring the specialty up to the specialty podium. Accidentology, sports events, and natural disasters enrich medicine in general and PRM in particular. Indeed, all these events create disability through a participatory and integrative strategy of the patients; PMR always takes up the challenge.