Advances in covalent organic frameworks for cancer phototherapy

The global prevalence of cancer presents a formidable challenge to medical systems, compelling the pursuit of novel and effective therapeutic modalities to improve patient survival rates. In this context, cancer phototherapy, encompassing both photodynamic (PDT) and photothermal (PTT) therapies, stands out as a targeted, minimally invasive modality to trigger the selective ablation of cancer cells. Covalent organic frameworks (COFs), with their distinct crystalline and porous nature, excellent biocompatibility, and chemical robustness, are increasingly recognized as outstanding materials to propel cancer phototherapy forward. In this review, we focus on examining the application of COF nanoparticles in the domain of PDT and PTT, demonstrating their potent anti-cancer capabilities. We pay special attention to combination therapies that exploit COFs, particularly those that elicit immunogenic cell death. These synergistic approaches offer considerable promise for the enhancement of cancer therapy efficiency. Additionally, we address the prevalent hurdles associated with COF-based cancer phototherapy, such as toxicity concerns, in vivo stability issues, and the complexities of photo agent delivery. We also discuss potential methods to overcome these barriers, especially through surface modifications of COFs. The review concludes by charting prospective research paths and the urgent need for the establishment of standardized procedures to fast-track the clinical adoption of COF-based phototherapy. By offering a detailed yet succinct outline of the capabilities of COFs in advancing cancer phototherapy, this article provides valuable insights for investigators in this vibrant field.