RESUMO
Exosome is a self-secreted phospholipid bilayer nanovesicles, and has shown great potential in drug delivery field due to the important advantages of low immunogenicity and homologous targeting. Phototherapy, mainly includes photodynamic therapy (PDT) and photothermal therapy (PTT), utilize light to activate photoactive drug for tumor cell killing. The advanced therapeutic strategy shows low toxic side-effect and non-invasion precise advantages, and thus has made great progress in tumor treatment over the past few years. Therefore, using exosomes as a drug delivery system to deliver phototherapeutic agents can improve therapeutic performances with a reduced side-effect, and further enhance their application potential for clinical tumor therapy. This review focus on the rising cross-subjects field involving exosomes and phototherapy, and mainly introduce the research progress and relative case of exosomes-based delivery system for cancer phototherapy. Additionally, the advantages and challenges of exosome-based phototherapy are also discussed and proposed.
RESUMO
Photodynamic therapy (PDT) has emerged as a more effective and promising treatment towards cancer therapy. PDT is a minimally invasive and spatially selective medical technique to destroy cancer cells without drug resistance, which has been increasingly applied in the clinical praxis alongside surgery, chemotherapy and radiotherapy. However, traditional PDTs use a high energy one-photon laser beam, which is far from the efficient optical window of mammalian tissue (650−950 nm). Moreover, it has great limitations in the depth of penetration, and induces the undesired light toxicity. The development of photosensitizers has always been a bottleneck to the effective application of PDT in clinical practice. From the first generation of hematoporphyrin derivatives to the third-generation photosensitizers with tumor targeting ability, they meet the urgent clinical needs to some extent, but they still can not satisfy the requirements of two-photon PDT. Therefore, the development of photosensitizers, which are capable of two-photon activated PDT, has become a promising approach. Among the various two-photon absorption photosensitizers, ruthenium (Ⅱ) polypyridyl complexes have been recognized as excellent candidates due to their attractive photophysical properties. This review is prepared to summarize the recent achievements in the application of ruthenium (Ⅱ) polypyridyl complexes as photosensitizers for two-photon PDT, as well as to provide guidance for the design of two-photon activated photosensitizers in future research.