Aggregation-Induced emission photosensitizer with lysosomal response for photodynamic therapy against cancer.

Photosensitizers play a key role in bioimaging and photodynamic therapy (PDT) of cancer. However, conventional photosensitizers usually do not achieve the desired efficacy in PDT due to their poor photostability, targeting ability, and responsiveness. Herein, we designed a series of photosensitizers with aggregation-induced emission (AIE) effect using benzothiazole- triphenylamine (BZT-triphenylamine) as the parent nucleus. The synthesized compound SIN ((E)-2-(4-(diphenylamino)styryl)-3-(4-iodobutyl)benzo[d]thiazol-3-ium) exhibits good biocompatibility, photostability, and bright emission in the near-infrared range (600-800 nm). The fluorescence emission intensity is responsive to viscosity, with significant fluorescence enhancement (48 times) and high fluorescence quantum yield (4.45 %) at high viscosity. Moreover, SIN has particular lysosome targeting properties with a Pearson correlation coefficient (PCC) of 0.97 and has good 1O2 generation ability under white light irradiation, especially in a weak acidic environment. Thus, SIN can realize good bioimaging ability and photodynamic therapeutic efficacy under the highly viscous and weakly acidic environment of lysosomes in the tumor cells. This study indicates that SIN has potential as a multifunctional organic photosensitizer for bioimaging and PDT of tumor.

Rotor-based image-guided therapy of glioblastoma.

Glioblastoma (GBM), deep in the brain, is more challenging to diagnose and treat than other tumors. Such challenges have blocked the development of high-impact therapeutic approaches that combine reliable diagnosis with targeted therapy. Herein, effective cyanine dyes (IRLy) with the near-infrared two region (NIR-II) adsorption and aggregation-induced emission (AIE) have been developed via an "extended conjugation & molecular rotor" strategy for multimodal imaging and phototherapy of deep orthotopic GBM. IRLy was synthesized successfully through a rational molecular rotor modification with stronger penetration, higher signal-to-noise ratio, and a high photothermal conversion efficiency (PCE) up to ∼60%, which can achieve efficient NIR-II photo-response. The multifunctional nanoparticles (Tf-IRLy NPs) were further fabricated to cross the blood-brain barrier (BBB) introducing transferrin (Tf) as a targeting ligand. Tf-IRLy NPs showed high biosafety and good tumor enrichment for GBM in vitro and in vivo, and thus enabled accurate, efficient, and less invasive NIR-II multimodal imaging and photothermal therapy. This versatile Tf-IRLy nanosystem can provide a reference for the efficient, precise and low-invasive multi-synergistic brain targeted photo-theranostics. In addition, the "extended conjugation & molecular rotor" strategy can be used to guide the design of other photothermal agents.

Chitosan/NH2-MIL-125 (Ti) scaffold loaded with doxorubicin for postoperative bone tumor clearance and osteogenesis: An in vitro study.

Surgical resection remains the primary treatment modality for bone tumors. However, it is prone to local bone defects and tumor recurrence. Therefore, there is an urgent need for multifunctional biomaterials that combine tumor treatment and bone repair after bone tumor surgery. Herein, a chitosan composite scaffold (CS/DOX@Ti-MOF) was designed for both tumor therapy and bone repair. Among them, the amino-functionalized Ti-based metal-organic framework (NH2-MIL-125 (Ti), Ti-MOF) has a high specific surface area of 1116 m2/g and excellent biocompatibility, and promotes osteogenic differentiation. The doxorubicin (DOX) loading capacity of Ti-MOF was 322 ± 21 mg/g, and DOX@Ti-MOF has perfect antitumor activity. Furthermore, the incorporation of DOX@Ti-MOF improved the physical and mechanical properties of the composite scaffolds, making the scaffold surface rough and favorable for cells to attach. CS/DOX@Ti-MOF retains the unique properties of each component. It responds to the release of DOX in the tumor microenvironment to remove residual tumor cells, followed by providing a site for cell attachment, proliferation, and differentiation. This promotes bone repair and achieves the sequential treatment of postoperative bone tumors. Overall, CS/DOX@Ti-MOF may be a promising substitute for postoperative bone tumor clearance and bone defect repair. It also provides a possible strategy for postoperative bone tumor treatment.