Monodisperse Ultra-Large-Pore Silica Coated Polystyrene Core-Shell Microbeads via Layer-by-Layer Assembly for Nano-Micro Composite

Polystyrene （PS） @SiO2 core-shell microbeads with large pore and large particle size were prepared via layer-by-layer（LBL）assembly technique for potential applications in nano-micro composites. Negative silica nanoparticles synthesized via modified St6ber method and cationic poly （diallyldimethylammonium chloride） were alternately adsorbed on the surface of microbeads. Zeta potential, size, and morphology of the microbeads were monitored during LBL assembly process to ensure the successful deposition of silica nanoparticles. The porous shell was characterized using nitrogen adsorption and desorption analyses, and the surface area, volume and diame- ter of the pores were derived. It is found that the porous shell thickness and the pore size can be tuned by changing the coating times of silica nanoparticles. Finally, PS@SiO2 core-shell microbeads with 5 grn PS solid core and 350 nm mesoporous shell （mean BJH pore diameter is ~27 nm） were used to load CdSe/ZnS quantum dots （QDs）. The fluorescence microscopic image and the optical amplification of the QDs-embedded microbeads （QDBs） indicate that the as-prepared core-shell microbeads can provide adequate space for QDs and may be useful for further application of nano-micro composites.

Leukocyte/platelet hybrid membrane-camouflaged dendritic large pore mesoporous silica nanoparticles co-loaded with photo/chemotherapeutic agents for triple negative breast cancer combination treatment

Triple-negative breast cancer(TNBC)is an aggressive subset of breast cancer and currently lacks effective therapeutic targets.As two main phototherapeutic methods,photothermal therapy(PTT)and photodynamic therapy(PDT)show many advantages in TNBC treatment,and their combination with chemotherapy can achieve synergistic therapeutic effects.In the present study,a biomimetic nanoplatform was developed based on leukocyte/platelet hybrid membrane(LPHM)and dendritic large pore mesoporous silicon nanoparticles(DLMSNs).A near infrared(NIR)fluorescent dye IR780 and a chemotherapeutic drug doxorubicin(DOX)were co-loaded into the large pores of DLMSNs to prepare DLMSN@DOX/IR780(DDI)nanoparticles(NPs),followed by camouflage with LPHM to obtain LPHM@DDI NPs.Through the mediation of LPHM,LPHM@DDI NPs showed an excellent TNBC-targeting ability and very high PTT/PDT performances in vitro and in vivo.Upon NIR laser irradiation,LPHM@DDI NPs exhibited synergistic cytotoxicity and apoptosis-inducing activity in TNBC cells,and effectively suppressed tumor growth and recurrence in TNBC mice through tumor ablation and anti-angiogenesis.These synergistic effects were sourced from the combination of PTT/PDT and chemotherapy.Altogether,this study offers a promising biomimetic nanoplatform for efficient co-loading and targeted delivery of photo/chemotherapeutic agents for TNBC combination treatment.

Cell Membrane-camouflaged Multi-functional Dendritic Large Pore Mesoporous Silica Nanoparticles for Combined Photothermal Therapy and Radiotherapy of Cancer

Combining photothermal therapy and radiotherapy(PTT-RT) with reducing tumor hypoxia acts as an important antitumor modality. However, it is a great challenge to realize photothermal therapy, radiotherapy and exogenous oxygen supply in one nanosystem. To realize a combination of the three functions, we fabricated a red blood cell membrane(RBCm)-camouflaged, red blood cell content(RBCc) and the copper sulfide(CuS) co-loaded dendritic large pore mesoporous silica nanoparticle(DLMSN/CuS/RBCc/ RBCm). The cell membrane coating endowed the nanoparticles with good stability in the physiological environment, and CuS allowed the nanoparticle exhibiting good photothermal and radiosensitization properties. RBCc loaded nanoparticle DLMSN/CuS/RBCc enhanced superior anti-tumor effect than DLMSN/CuS during combined PTT-RT therapy because the introduction of RBCc increased the exogenous oxygen supply. The in vitro study further demonstrated that the combination of photothermal therapy and radiotherapy induced superior antitumor efficacy than single therapy. Our work thus presents a unique multifunctional nanoscale platform favorable for combined PTT and RT.