A new bioconjugate nanostructure was constructed by using photosensitizer-incorporated mixed lipid-coated gold nanocages for two-photon photothermal/photodynamic cancer therapy in vitro with high efficiency. Scanning electron microscopic and transmission electron microscopic images reveal that the precursors and bioconjugate nanostructure as-prepared are narrowly dispersed and possess uniform morphologies. The relevant energy dispersion X-ray analysis and UV-vis spectra indicate that the bioconjugate nanostructure above was assembled successfully and has a strong absorption in the near-infrared region. Fluorescence and electronic spin resonance results show that the gold nanocage in the bioconjugate nanostructure can dramatically quench the photosensitizer and inhibit the production of singlet oxygen, which is supposed to alleviate the photosensitizers' unwanted side effects originating from their nontargeted distribution. We have demonstrated that as the nanocomplex is internalized by cancer cells, under two-photon illumination, photodynamic anticancer treatment is dramatically enhanced by the photothermal effect.

Targeted drug delivery is an emerging technological strategy that enables nanoparticle systems to be responsive for tumor therapy. Magnetic mesoporous silica nanoparticles (MMSNs) were cloaked with red blood cell membrane (RBC). This integrates long circulation, photosensitizer delivery, and magnetic targeting for cancer therapy. In vivo experiments demonstrate that RBC@MMSNs can avoid immune clearance and achieve magnetic field (MF)-induced high accumulation in a tumor. When light irradiation is applied, singlet oxygen rapidly generates from hypocrellin B (HB)-loaded RBC@MMSN and leads to the necrosis of tumor tissue. Such a RBC-cloaked magnetic nanocarrier effectively integrates immunological adjuvant, photosensitizer delivery, MF-assisted targeting photodynamic therapy, which provides an innovative strategy for cancer therapy.

We demonstrate that large-scale autofluorescent tea polyphenol (TP)-based core@shell nanostructures can be assembled by one-pot preparation under microwave irradiation within 1 min. The formation mechanism of the heterogeneous well-defined core@shell nanocomposites involves microwave-assisted oxidation-inducing self-assembly and directed aggregation. The strategy is general to construct Ag@TP and Au@TP nanocomposites. Moreover, a simple galvanic replacement reaction was introduced to synthesize hollow Au/Ag@TP bioconjugates with near-infrared (NIR) absorption, which could be exploited for NIR cancer diagnosis and treatment. It could be expected that more complex alloy@TP nanostructures can be obtained under proper reaction conditions. Furthermore, as a first application, it is shown that the heterogeneous Ag@TP nanostructures can strongly inhibit Escherichia coli growth, while they exhibit no obvious normal cell toxicity. The sharp contrast of the two effects promises that the nanocomposites are excellent low toxicity biomaterials for selective antibacterial treatment.