Recent advances in glioma microenvironment-response nanoplatforms for phototherapy and sonotherapy.

The newly emerging nanotheranostic strategies including photodynamic therapy (PDT), photothermal therapy (PTT) and sonodynamic therapy (SDT) have exhibited their unbeatable advantages in treatment and prognosis of glioma tumors as compared to conventional ones like chemotherapy, radiotherapy and surgery. Meanwhile, the components of glioma microenvironment including blood brain barrier (BBB), oxidative stress, hypoxia and angiogenesis, play essential roles in glioma initiation, progression, invasion, recurrence and drug resistance. More importantly, the nanoparticles can modulate the glioma environments to increase targeting capability, monitor the glioma growth, and enhance therapy outcomes. In this review, we will introduce the basic components of glioma microenvironment, the role that glioma microenvironment played on tumor development and progression, and the key perspectives associated with glioma microenvironment-based multifunctional nanoplatform design. In particular, recent advances in glioma microenvironment-response nanoparticles for phototherapy (PTT and PDT) and sonotherapy will be discussed in detail. Finally, the challenges related to the clinical transition for nanomedicine-based glioma theranostics will be addressed.

Highly Efficient Water-Soluble Photosensitizer Based on Chlorin: Synthesis, Characterization, and Evaluation for Photodynamic Therapy.

The clinical applications of many photosensitizers (PSs) are limited because of their poor water solubility, weak tissue penetration, low chemical purity, and severe toxicity in the absence of light. We designed a novel chlorin-based PS (designated as HPS) to achieve fluorescence image-guided photodynamic therapy (PDT) with efficient ROS generation. In addition to its simple fabrication process, HPS has other advantages such as excellent water solubility, strong NIR absorption, and high biocompatibility upon chemical functionalization for enhanced phototherapy. HPS exhibited high photodynamic performance against lung cancer and breast cancer cells by generating a large amount of singlet oxygen (1O2) under 654 nm laser irradiation. HPS accumulated into multiple organelles such as mitochondria and the endoplasmic reticulum and triggered cell apoptosis by laser exposure. In the tumor-bearing mice, in vivo, HPS showed an optimal half-life in circulation and achieved fluorescence-image-guided PDT within the irradiation window, resulting in effective tumor growth inhibition and the prolonged survival of animals. Moreover, the antitumor PDT effect of HPS was close to the clinical trial phase II stage of HPPH even at the low dosage of 0.32 mg/kg (under 75 J/cm2 laser), while the systemic safety of HPS was much higher. In conclusion, HPS is a novel water-soluble chlorin derivative with excellent PDT potential for clinical transformation.

Active-Targeting NIR-II Phototheranostics in Multiple Tumor Models Using Platelet-Camouflaged Nanoprobes.

Cancer phototheranostics in the second near-infrared window (NIR-II, 1000-1700 nm) has recently attracted much attention owing to its high efficacy and good safety compared with that in the first near-infrared window (NIR-I, 650-950 nm). However, the lack of theranostic nanoagents with active-targeting features limits its further application in cancer precision therapies. Herein, we constructed platelet-camouflaged nanoprobes with active-targeting characteristics for NIR-II cancer phototheranostics. The as-prepared biomimetic nanoprobes can not only escape phagocytosis by macrophages but also specifically bind to CD44 on the surface of most cancer cells. We evaluated the active-targeting performance of biomimetic nanoprobes in pancreatic cancer, breast cancer, and glioma mouse models and achieved NIR-II photoacoustic imaging with a high signal-to-background ratio and photothermal treatment with excellent tumor growth inhibition. Our results show the great potential of platelet-camouflaged nanoprobes with NIR-II active-targeting features for cancer precision diagnosis and efficient therapies.