Intracellular “activated” two-photon photodynamic therapy by fluorescent conveyor and photosensitizer co-encapsulating pH-responsive micelles against breast cancer

Abstract

The application of photodynamic therapy (PDT) for the diagnosis and treatment of cancer is hindered by the intrinsic defects of the currently available photosensitizers (PSs), such as poor water solubility and limited light-penetration depth. In this study, pH-responsive polymeric micelles that co-encapsulate therapeutic PSs and organooxotin two-photon compounds were applied for two-photon PDT (TP-PDT) against breast cancer. The TP-PDT effect of the drug-loaded micelles was “activated” when the micelles turned into aggregates at a triggering pH level. The in vitro therapeutic effect was evaluated on 4T1 murine breast cancer cells by viability assays, real-time morphology collapsing, and reactive oxygen species determination. Time-dependent ex vivo organ distribution and in vivo anticancer efficacy results suggested that the drug carriers could accumulate in tumors and suppress tumor growth by TP-PDT. The delivery system could enhance the solubility and distribution of PSs and, if administered along with a tissue-penetrating prolonged light source, could thus have good potential for cancer therapy.

Bone morphogenetic protein and activin membrane‑bound inhibitor overexpression inhibits gastric tumor cell invasion via the transforming growth factor‑β/epithelial‑mesenchymal transition signaling pathway

“…All cells were cultured in a humidified atmosphere containing 5% CO 2 at 37°C. Intracellular pH was analyzed as previously described ( 26 ).…”

Functional Polymer Nanocarriers for Photodynamic Therapy

“…Apart from the biodistribution, activation of PSs is another keypoint [132,133]. Although the PS can escape from the carrier and recover its activation after the biodegradation of polymer nanocarriers, stimuli responsive drug delivery systems are preferred [134,135,136,137,138,139].…”

<p>Chlorins e6 loaded silica nanoparticles coated with gastric cancer cell membrane for tumor specific photodynamic therapy of gastric cancer</p>

“…Photodynamic therapy (PDT) is a rapidly developing technic that employ photodynamic agents to transfer NIR light into highly ROSto exert cytotoxic on cells 19. As a noninvasive and harmless approach, PDT is well recognized as a preferable measure for cancer therapy 20. Chlorins e6 (Ce6) is known as a commonly adopted PDT agent, both in experimental and clinical applications, which has irreplaceable advantages over other agents 21,22.…”