Novel Foscan®-derived ring-fused chlorins for photodynamic therapy of cancer

Photodynamic Therapy in the Treatment of Cancer-The Selection of Synthetic Photosensitizers

Photodynamic therapy (PDT) is a promising cancer treatment method that uses photosensitizing (PS) compounds to selectively destroy tumor cells using laser light. This review discusses the main advantages of PDT, such as its low invasiveness, minimal systemic toxicity and low risk of complications. Special attention is paid to photosensitizers obtained by chemical synthesis. Three generations of photosensitizers are presented, starting with the first, based on porphyrins, through the second generation, including modified porphyrins, chlorins, 5-aminolevulinic acid (ALA) and its derivative hexyl aminolevulinate (HAL), to the third generation, which is based on the use of nanotechnology to increase the selectivity of therapy. In addition, current research trends are highlighted, including the search for new photosensitizers that can overcome the limitations of existing therapies, such as heavy-atom-free nonporphyrinoid photosensitizers, antibody-drug conjugates (ADCs) or photosensitizers with a near-infrared (NIR) absorption peak. Finally, the prospects for the development of PDTs are presented, taking into account advances in nanotechnology and biomedical engineering. The references include both older and newer works. In many cases, when writing about a given group of first- or second-generation photosensitizers, older publications are used because the properties of the compounds described therein have not changed over the years. Moreover, older articles provide information that serves as an introduction to a given group of drugs.

Photodynamic therapy for cancer: mechanisms, photosensitizers, nanocarriers, and clinical studies

Photodynamic therapy (PDT) is a temporally and spatially precisely controllable, noninvasive, and potentially highly efficient method of phototherapy. The three components of PDT primarily include photosensitizers, oxygen, and light. PDT employs specific wavelengths of light to active photosensitizers at the tumor site, generating reactive oxygen species that are fatal to tumor cells. Nevertheless, traditional photosensitizers have disadvantages such as poor water solubility, severe oxygen-dependency, and low targetability, and the light is difficult to penetrate the deep tumor tissue, which remains the toughest task in the application of PDT in the clinic. Here, we systematically summarize the development and the molecular mechanisms of photosensitizers, and the challenges of PDT in tumor management, highlighting the advantages of nanocarriers-based PDT against cancer. The development of third generation photosensitizers has opened up new horizons in PDT, and the cooperation between nanocarriers and PDT has attained satisfactory achievements. Finally, the clinical studies of PDT are discussed. Overall, we present an overview and our perspective of PDT in the field of tumor management, and we believe this work will provide a new insight into tumor-based PDT.

Clinical efficacy of photodynamic therapy of oral potentially malignant disorder

OBJECTIVE

To investigate the clinical efficacy of aminovalerate hydrochloride photodynamic therapy (PDT) for oral potentially malignant disorder (OPMD),oral leukoplakia (OLK), along with identifying the influencing factors.Additionally, the study aims to detect the rates of recurrence and malignancy after PDT.

METHOD

60 patients with OPMD who received PDT at our hospital from 2006 to 2021 were included in this study. Relevant patient medical data were collected and analyzed using SAS 9.4 software.The Mann-Whitney U test was used to retrospectively analyze the factors influencing clinical efficacy, as well as recurrence rate and malignant transformation rate (MTR) after treatment.

RESULT

Among the 60 OPMD patients receiving PDT, complete remission in 13 (21.67 %), partial remission in 39 (65.00 %), and no remission in eight (13.33 %), resulting in an overall effective rate of 86.67 %.Fifteen patients experienced relapse, leading to a recurrence rate of 25.00 %. Among these relapses,11 patients occurred within one year after treatment, corresponding to an 18.33 % recurrence rate during that period. Moreover, nine patients developed malignant transformation (MT), resulting in an MTR of 15.00 %. Out of these patients, six individuals developed MT within one year after treatment, resulting in a one-year MTR of 10.00 %.

CONCLUSION

The study findings indicate that PDT shows promising clinical efficacy in the treatment of OPMD, with relatively limited and tolerable postoperative adverse reactions. However, there remains a certain rate of recurrence and malignancy after treatment. Therefore, close attention should be paid to postoperative monitoring, regular follow-up, and further expansion of the sample size to observe its long-term efficacy.

Photodynamic therapy in brain cancer: mechanisms, clinical and preclinical studies and therapeutic challenges

Cancer is a main cause of death and preferred methods of therapy depend on the type of tumor and its location. Gliomas are the most common primary intracranial tumor, accounting for 81% of malignant brain tumors. Although relatively rare, they cause significant mortality. Traditional methods include surgery, radiotherapy and chemotherapy; they also have significant associated side effects that cause difficulties related to tumor excision and recurrence. Photodynamic therapy has potentially fewer side effects, less toxicity, and is a more selective treatment, and is thus attracting increasing interest as an advanced therapeutic strategy. Photodynamic treatment of malignant glioma is considered to be a promising additional therapeutic option that is currently being extensively investigated in vitro and in vivo. This review describes the application of photodynamic therapy for treatment of brain cancer. The mechanism of photodynamic action is also described in this work as it applies to treatment of brain cancers such as glioblastoma multiforme. The pros and cons of photodynamic therapy for brain cancer are also discussed.