ABSTRACT
Photodynamic therapy (PDT) is a promising strategy for effective cancer treatment. However, it still faces severe challenges, including poor laser penetration and insufficient oxygen (O2) in solid tumors. Here, we constructed intelligent O2self-supplied nanoparticles (NPs) for tumor hypoxia relief as well as effective chemiexcited PDT. Oxygen-carrying NPs (BSA@TCPO NPs) were obtained via the self-assembly of bovine serum albumin (BSA), bis[3,4,6-trichloro2-(pentyloxycarbonyl)phenyl]oxalate (TCPO), perfluorohexane (PFH), and chlorin e6 (Ce6). In H2O2-overexpressed tumor cells, TCPO in the NPs reacted with H2O2, releasing energy to activate the photosensitizer Ce6 and generate cytotoxic singlet oxygen (1O2) to kill tumor cells in a laser irradiation-independent manner. Moreover, the O2carried by PFH not only reduced therapeutic resistance by alleviating tumor hypoxia but also increased1O2generation for enhanced chemiexcited PDT. The remarkable cytotoxicity to various cancer cell lines and A549 tumors demonstrated the advantage of BTPC in alleviating the hypoxic status and inhibiting tumor growth. Our results demonstrate that BTPC is a promising nanoplatform for cancer therapy.
Subject(s)
Nanoparticles , Neoplasms , Photochemotherapy , Humans , Photochemotherapy/methods , Hydrogen Peroxide , Photosensitizing Agents , Neoplasms/drug therapy , Oxygen , Cell Line, TumorABSTRACT
A facile in situ approach has been designed to synthesize zinc ferrite/mesoporous silica guest-host composites. Chelating surfactant, N-hexadecyl ethylenediamine triacetic acid, was employed as structure-directing agent to fabricate mesoporous silica skeleton and simultaneously as complexing agent to incorporate stoichiometric amounts of zinc and iron ions into silica cavities. On this basis, spinel zinc ferrite nanoparticles with grain sizes less than 3 nm were encapsulated in mesoporous channels after calcination. The silica mesostructure, meanwhile, displayed a successive transformation from hexagonal p6mm through bicontinuous cubic Ia3Ì d to lamellar phase with increasing the dopant concentration in the initial template solution. In comparison with zinc ferrite nanopowder prepared without silica host, the composite with bicontinuous architecture exhibited higher sensitivity, lower detection limit, lower optimum working temperature, quicker response, and shorter recovery time in sensing performance toward hydrogen sulfide. The significant improvements are from the high surface-to-volume ratio of the guest oxides and the three-dimensional porous structure of the composite. We believe the encapsulation route presented here may pave the way for directly introducing complex metal oxide into mesoporous silica matrix with tailorable mesophases for applications in sensing or other fields.
ABSTRACT
A novel anionic surfactant-templated synthesis of ZnO/mesoporous silica nanocomposites has been carried out by using N-hexadecylethylenediamine triacetate (HED3A), a triprotic surfactant, as the structure-directing agent. The chelating template can capture zinc ions in solution and then direct the mesophase formation, enabling an amount of zinc oxide to be embedded in the porous silica matrix during calcination. With variation of the molar ratio of Zn(2+) to HED3A in the template, a series of composites with different doping amounts were obtained after the removal of organic components. The variation of the zinc ion concentration in the initial template solution induces an evolution of the silica mesophase, presumably due to the change in electronegativity of the HED3A headgroup caused by the chelating effect. Spectroscopic studies show a strong host-guest interaction between the silica pore walls and ultrafine ZnO nanoparticles. The photoluminescence properties of the resulting composites exhibit a size-dependent light emission and quantum-confinement effect of ZnO, accompanied by an infrequent violet emission originating from the ZnO-SiO(2) interface.