Emissive Nanoparticles from Co-assembly of Metallatetragon and Amphiphilic Tetraphenylethylene for Cancer Theranostics

Nanomaterials in crossroad of autophagy control in human cancers: Amplification of cell death mechanisms

Cancer is the result of genetic abnormalities that cause normal cells to grow into neoplastic cells. Cancer is characterized by several distinct features, such as uncontrolled cell growth, extensive spreading to other parts of the body, and the ability to resist treatment. The scientists have stressed the development of nanostructures as novel therapeutic options in suppressing cancer, in response to the emergence of resistance to standard medicines. One of the specific mechanisms with dysregulation during cancer is autophagy. Nanomaterials have the ability to specifically carry medications and genes, and they can also enhance the responsiveness of tumor cells to standard therapy while promoting drug sensitivity. The primary mechanism in this process relies on autophagosomes and their fusion with lysosomes to break down the components of the cytoplasm. While autophagy was initially described as a form of cellular demise, it has been demonstrated to play a crucial role in controlling metastasis, proliferation, and treatment resistance in human malignancies. The pharmacokinetic profile of autophagy modulators is poor, despite their development for use in cancer therapy. Consequently, nanoparticles have been developed for the purpose of delivering medications and autophagy modulators selectively and specifically to the cancer process. Furthermore, several categories of nanoparticles have demonstrated the ability to regulate autophagy, which plays a crucial role in defining the biological characteristics and response to therapy of tumor cells.

PEGylated AIEgens for dual sensing of ATP and H2S and cancer cells photodynamic therapy

Fluorescent sensors have been widely applied for biosensing, but probes for both multiple analytes sensing and photodynamic therapy (PDT) effect are less reported. In this article, we reported three AIE-based probes anchored with different mass-weight polyethylene glycol (PEG) tails, i.e., TPE-PEG160, TPE-PEG350, and TPE-PEG750, for both adenosine-5'-triphosphate (ATP) and hydrogen sulfide (H2S) detection and also cancer cells photodynamic therapy. TPE-PEGns (n = 160, 350 and 750) contain the tetraphenylethylene-based fluorophore core, the pyridinium and amide anion binding sites, the H2S cleavable disulfide bond, and the hydrophilic PEG chain. They exhibit a good amphiphilic property and can self-assemble nona-aggregation with a moderated red emission in an aqueous solution. Importantly, the size of aggregation, photophysical property, sensing ability and photosensitivity of these amphiphilic probes can be controlled by tuning the PEG chain length. Moreover, the selected probe TPE-PEG160 has been successfully used to detect environmental H2S and image ATP levels in living cells, and TPE-PEG750 has been used for photodynamic therapy of tumor cells under light irradiation.

Type-I Photodynamic Therapy Induced by Pt-Coordination of Type-II Photosensitizers into Supramolecular Complexes

Platinum supramolecular complexes based on photosensitizers have garnered great interest in photodynamic therapy (PDT) due to Pt (II) centers as chemotherapeutic agents to eliminate tumor cells completely, which greatly improve the antitumor efficacy of PDT. However, in comparison to precursor photosensitizer ligand, the formed platinum supramolecular complexes typically exhibit inferior outcomes in terms of reactive oxygen species (ROS) generation. How to boost ROS generation in the formed platinum supramolecular complexes for enhanced PDT is an enticing yet highly challenging task. Here we report a Pt-coordination-based dimeric photosensitizer complex (Cz-BTZ-Py)2Pt(OTf)2. It is found that comparing with photosensitizer ligand Cz-BTZ-Py, the formed supramolecular complex exhibit redshifts of absorption wavelength as well as enhanced ROS generation efficiency. Moreover, type-I ROS generation (O2⋅-) is produced in the formed platinum supramolecular complexes mainly due to a reduced energy gap ΔEST resulting from exciton coupling between two photosensitizer ligands. And type-I ROS (O2⋅-) generation significantly amplifies the photodynamic therapy (PDT) outcomes. In vitro evaluation shows excellent photochemotherapy performance of (Cz-BTZ-Py)2Pt(OTf)2 nanoparticles. We anticipate this work would provide a novel approach to design type-I photosensitizers for efficient PDT.