Nanomedicine in Clinical Photodynamic Therapy for the Treatment of Brain Tumors

Abstract

The current treatment for malignant brain tumors includes surgical resection, radiotherapy, and chemotherapy. Nevertheless, the survival rate for patients with glioblastoma multiforme (GBM) with a high grade of malignancy is less than one year. From a clinical point of view, effective treatment of GBM is limited by several challenges. First, the anatomical complexity of the brain influences the extent of resection because a fine balance must be struck between maximal removal of malignant tissue and minimal surgical risk. Second, the central nervous system has a distinct microenvironment that is protected by the blood–brain barrier, restricting systemically delivered drugs from accessing the brain. Additionally, GBM is characterized by high intra-tumor and inter-tumor heterogeneity at cellular and histological levels. This peculiarity of GBM-constituent tissues induces different responses to therapeutic agents, leading to failure of targeted therapies. Unlike surgical resection and radiotherapy, photodynamic therapy (PDT) can treat micro-invasive areas while protecting sensitive brain regions. PDT involves photoactivation of photosensitizers (PSs) that are selectively incorporated into tumor cells. Photo-irradiation activates the PS by transfer of energy, resulting in production of reactive oxygen species to induce cell death. Clinical outcomes of PDT-treated GBM can be advanced in terms of nanomedicine. This review discusses clinical PDT applications of nanomedicine for the treatment of GBM.

Therapeutic Applications of Nanomedicine: Recent Developments and Future Perspectives

“…In various other domains, such as head and neck malignancies, urogenital malignancies, breast malignancies [36], intracranial malignancies [37], and gastrointestinal malignancies, PDT has shown extensive potential. With the rational design of novel nanoscale photosensitizers, such as overcoming the challenges of the blood-brain challenges using ultra-small NanoPSs, the prospects for PDT in brain tumor treatment are increasingly promising [38]. Additionally, clinical research on PDT for various malignancies, including ovarian cancer, endometrial cancer, cervical cancer, osteosarcoma, and hematologic malignancies, is vigorously ongoing.…”

ROS regulation in gliomas: implications for treatment strategies

“…In general, a well-functioning nanodrug delivery platform can typically enhance the therapeutic effects of PDT ( 330 ), SDT ( 331 ), and CDT ( 332 ) for the treatment of glioma. Moreover, optimizing key components of nanodrug delivery platforms can be an effective strategy to break through the BBB.…”

A review of natural products and small‐molecule therapeutics acting on central nervous system malignancies: Approaches for drug development, targeting pathways, clinical trials, and challenges

“…Although brain cancers exhibit a wide range of neoplasms, including limited or metastatic forms, the standard treatment commonly includes surgery, chemotherapy, radiotherapy, and immunotherapy. Chemotherapy for CNS cancers is still regarded as one of the most challenging treatments in the clinic (Gaudino et al, 2022; Ghajar‐Rahimi et al, 2022; H. S. Kim & Lee, 2022; Koekkoek et al, 2023; Lutz et al, 2022). Despite new anticancer drug developments in recent years, the prognosis for brain cancer patients, particularly those with malignant tumors, has remained poor (Koekkoek et al, 2023).…”