Dendritic mesoporous silica nanoparticles for enzyme immobilization

Dendritic mesoporous silica nanoparticles(DMSNs)are a new class of solid porous materials used for enzyme immobilization support due to their intrinsic characteristics,including their unique open central-radial structures with large pore channels and their excellent biocompatibility.In this review,we review the recent progress in research on enzyme immobilization using DMSNs with different structures,namely,flower-like DMSNs and tree-branch-like DMSNs.Three DMSN synthesis methods are briefly compared,and the distinct characteristics of the two DMSN types and their effects on the catalytic performance of immobilized enzymes are comprehensively discussed.Possible directions for future research on enzyme immobilization using DMSNs are also proposed.

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.

Hierarchical dual-porous hydroxyapatite doped dendritic mesoporous silica nanoparticles based scaffolds promote osteogenesis in vitro and in vivo

Biomaterial based scaffolds for treating large bone defects require excellent biocompatibility and osteoconductivity.Here we report on the fabrication of hydroxyapatite-dendritic mesoporous silica nanoparticles(HA-DMSN)based scaffolds with hierarchical micro-pores(5µm)and nano-pores(6.4 nm),and their application for bone regeneration.The in vitro studies demonstrated good biocompatibility of dissolution extracts,as well as enhanced osteogenic potential indicated by dose-dependent upregulation of bone marker gene expression(osteocalcin gene(OCN),osteopontin gene(OPN),collagen type I alpha 1 gene(CoL1A1),runt-related transcription factor 2 gene(RUNX2),and integrin-binding sialoprotein gene(IBSP)),alkaline phosphatise(ALP)activity,and alizarin red staining.The in vivo studies showed that HA-DMSN scaffolds significantly increased bone formation in a rat cranial bone defect model after 4 weeks healing.Our study provides a simple method to fabricate promising inorganic scaffolds with hierarchical pores for bone tissue engineering.