[Preparation of borneol loaded hollow mesoporous silica nanoparticles and effect on borneol volatility].

The hollow mesoporous silica nanoparticles (HMSNs) were prepared by hard template method, with a size of 300 nm and shell thickness of 25 nm. Borneol was loaded with solvent impregnation method in order to solve the stability problem of borneol in pharmaceutics, and the BET, TEM and FT-IR were used to characterize the HMSNs and the borneol-HMSNs drug delivery system. The optimal drug loading time, maximum drug loading capacity and the volatility of borneol were investigated. The results showed that HMSNs which were prepared at room temperature and neutral conditions had good sphericity, achieved high drug loading of borneol in a short time, and the drug loading was up to 74.04% within 6 hours; meanwhile, volatility of borneol in the system was greatly improved. This novel drug delivery system provides a new idea for wide application of borneol in the traditional Chinese medicine.

A dual catalytic functionalized hollow mesoporous silica-based nanocarrier coated with bacteria-derived exopolysaccharides for targeted delivery of irinotecan to colorectal cancer cells.

In this study, we introduced a multifunctional hollow mesoporous silica-based nanocarrier (HMSN) for the targeted delivery of irinotecan (IRT) to colorectal cancer cells. Due to their large reservoirs, hollow mesoporous silica nanoparticles are suitable platforms for loading significant amounts of drugs for sustained drug release. To respond to pH and redox, HMSNs were functionalized with cerium and iron oxides. Additionally, they were coated with bacterial-derived exopolysaccharide (EPS) as a biocompatible polymer. In vitro analyses revealed that cytotoxicity induced in cancer cells through oxidative stress, mediated by mature nanocarriers (EPS.IRT.Ce/Fe.HMSN), was surprisingly greater than that caused by free drugs. Cerium and iron ions, in synergy with the drug, were found to generate reactive oxygen species when targeting the acidic pH within lysosomes and the tumor microenvironment. This, in turn, triggered cascade reactions, leading to cell death. In vivo experiments revealed that the proposed nanocarriers had no noticeable effect on healthy tissues. These findings indicate the selective delivery of the drug to cancerous tissue and the induction of antioxidant effects due to the dual catalytic properties of cerium in normal cells. Accordingly, this hybrid drug delivery system provides a more effective treatment for colorectal cancer with the potential for cost-effective scaling up.

Exploring Hollow Mesoporous Silica Nanoparticles as a Nanocarrier in the Delivery of Foot-And-Mouth Disease Virus-like Particle Vaccines.

Virus-like particle (VLP) vaccine is considered to be the most promising candidate alternative to the traditional inactivated vaccine for foot-and-mouth disease (FMD). To elicit a desired immune response, hollow mesoporous silica nanoparticles (HMSNs) have been synthesized and utilized as a nanocarrier for FMD VLP vaccine delivery. The as-prepared HMSNs displayed a relatively small particle size (∼260 nm), large cavity (∼150 nm), and thin wall (∼55 nm). The inherent structural superiorities make them ideal nanocarriers for the FMD VLP vaccine, which exhibited good biocompatibility, great protein-loading capacity, high antibody-response level, and protective efficiency, even comparable to commercial adjuvant ISA 206. All the results suggested that HMSNs may be a valid nanocarrier in VLP-based vaccines.

Controlled-release of apatinib for targeted inhibition of osteosarcoma by supramolecular nanovalve-modified mesoporous silica.

Targeted delivery of antitumor drugs has been recognized as a promising therapeutic modality to improve treatment efficacy, reduce the toxic side effects and inhibit tumor recurrence. In this study, based on the high biocompatibility, large specific surface area, and easy surface modification of small-sized hollow mesoporous silica nanoparticles ß-cyclodextrin (ß-CD)-benzimidazole (BM) supramolecular nanovalve, together with bone-targeted alendronate sodium (ALN) were constructed on the surface of small-sized HMSNs. The drug loading capacity and efficiency of apatinib (Apa) in HMSNs/BM-Apa-CD-PEG-ALN (HACA) were 65% and 25%, respectively. More importantly, HACA nanoparticles can release the antitumor drug Apa efficiently compared with non-targeted HMSNs nanoparticles in the acidic microenvironment of the tumor. In vitro studies showed that HACA nanoparticles exhibited the most potent cytotoxicity in osteosarcoma cells (143B cells) and significantly reduced cell proliferation, migration and invasion. Therefore, the drug-efficient release of antitumor effect of HACA nanoparticles is a promising way to treat osteosarcoma.

Amino Acid-functionalized hollow mesoporous silica nanospheres as efficient biocompatible drug carriers for anticancer applications.

Herein, a series of new amino acid-functionalized hollow mesoporous silica nanospheres (HMSNs) by post-grafting methods were prepared. These new materials were characterized by different techniques and were studied as matrices for the antineoplastic drug (cisplatin) transport and delivery. The results demonstrate that the surface functionalization of the carriers has a remarkable positive influence on the loading efficiency and release rate of cisplatin. The highest drug entrapment efficiency and the most optimal release properties were observed when the (2-(butylamino) ethyl) glycine groups are grafted on the HMSNs surface (AFS-2-HMSNs sample). Moreover, the in vitro cytotoxic effect of both empty and cisplatin-loaded AFS-2-HMSNs sample (CDDP@AFS-2-HMSNs) on MCF-7 cells (human breast adenocarcinoma cell line) and HepG2 cells (human liver carcinoma cell line) were evaluated by MTT assay. The most important outcome is that the empty carrier revealed no cytotoxicity to cancer cells. However, CDDP@AFS-2-HMSNs caused a notable inhibition of cell viability which was affected from the dose and time. Our results demonstrate that the synthesized materials could be used as carriers for drug delivery with controlled release applications.

Irinotecan/IR-820 coloaded nanocomposite as a cooperative nanoplatform for combinational therapy of tumor.

AIM: To enhance synergistic therapeutic effects in breast cancer therapy. Here, we used hollow mesoporous silica nanoparticles as a biocompatible carrier to coload chemotherapy drugs Irinotecan and near-infrared IR-820 dye, which enhanced antitumor efficacy by combining chemotherapy and phototherapy. METHODS: The successful synthesis of hollow mesoporous silica nanoparticles/Irinotecan/IR820 (HMII) nanocomplex was confirmed by Fourier  transform infrared spectroscopy and Fluorescence spectra. The photothermal conversion efficiency and antitumor efficiency in murine breast cancer cells (EMT-6) bearing mice were further evaluated. RESULTS: The results demonstrated that HMII enhanced the delivery of Irinotecan and IR-820 into EMT-6 cells. HMII generated a high temperature upon a near-infrared laser irradiation (808 nm), and showed higher therapeutic efficacy in EMT-6-bearing mice compared with either HMII without laser or free drug with a laser. CONCLUSION: HMII is a desired drug codelivery system to efficiently inhibit the growth of breast cancer.

Cargo-influences on the biodistribution of hollow mesoporous silica nanoparticles as studied by quantitative 19F-magnetic resonance imaging.

HYPOTHESIS: Biodistribution is a key issue when it comes to medical applications of nanomaterials. Hollow mesoporous silica nanoparticles (HMSNs) loaded with fluorine compounds can be applied as positive magnetic resonance imaging (MRI) contrast agents (CAs). These CAs exhibit an unusual biodistribution which is influenced by the cargo and which could be linked to their serum protein adsorption behaviour. EXPERIMENTS: HMSNs were post-synthetically loaded with perfluoro-15-crown-5-ether (PFCE). The 19F signal was quantified with MRI in a murine model. Furthermore protein adsorption tests were performed in full serum. FINDINGS: Quantitative analysis of the 19F-signal revealed that the particles were exclusively accumulating in the liver 24h post-injection, and no accumulation in other reticuloendothelial system (RES) organs like spleen or lung was observed. The protein corona around non-loaded and loaded particles was therefore analysed, and more proteins adsorbed on PFCE-loaded particles as compared to the bare particles, and importantly, the amount of apolipoproteins A-1 and A-2, was clearly elevated for the PFCE-loaded particles. The results underline that the type of cargo may have major influences on the biodistribution of mesoporous silica drug vectors.

Surfaces with Sustainable Superhydrophobicity upon Mechanical Abrasion.

Surfaces with sustainable superhydrophobicity have drawn much attention in recent years for improved durability in practical applications. In this study, hollow mesoporous silica nanoparticles (HMSNs) were prepared and used as reservoirs to load dodecyltrimethoxysilane (DDTMS). Then superhydrophobic surfaces were fabricated by spray coating HMSNs with DDTMS as particle stacking structure and polydimethylsiloxane (PDMS) as hydrophobic interconnection. The mechanical durability of the obtained superhydrophobic surface was evaluated by a cyclic sand abrasion. It was found that once the surface was mechanically damaged, new roughening structures made of the cavity of the HMSNs would expose and maintain suitable hierarchical roughness surrounded by PDMS and DDTMS, favoring sustainable superhydrphobicity of the coating. The surfaces could sustain superhydrophobicity even after 1000 cycles of sand abrasion. This facile strategy may pave the way to the development of robust superhydrophobic surfaces in practical applications.

Hollow mesoporous silica nanoparticles facilitated drug delivery via cascade pH stimuli in tumor microenvironment for tumor therapy.

To efficiently deliver anti-cancer drug to tumor site and reduce its toxic side effects on normal tissues, a polyethylene glycol (PEG) shielding and tumor microenvironment triggering cascade pH-responsive hollow mesoporous silica nanoparticles (HMSNs) drug delivery system was fabricated. 3-(3, 4-dihydroxyphenyl) propionic acid (DHPA) functionalized beta-cyclodextrin (ß-CD) was grafted onto the surfaces of HMSNs via boronic acid-catechol ester bonds. Then, PEG conjugated adamantane (Ada) was anchored on HMSNs-ß-CD nanocarrier via host-gust interaction. Various techniques proved the successful fabrication of the system. The in vitro tests confirmed that the system was biocompatible. After the system permeating into tumor via enhanced permeability and retention (EPR) effect, the benzoic-imine bonds between the PEG and Ada were cleaved under weak acid condition in tumor microenvironment (pH 6.8), while the dissociated PEG protective layer facilitating cellular uptake of HMSNs system. Subsequently, the boronic acid-catechol ester bonds linkers further hydrolyzed under even low endosomal pH (4.5-6.5) condition for intracellular drug delivery, leading to efficient cell apoptosis. The in vivo results demonstrated that drug loaded HMSNs significantly inhibited tumor growth while only with minimal toxic side effects. The strategy provides new insight into the development of new generation of drug delivery carriers triggering by tumor microenvironment.

A facile route for rapid synthesis of hollow mesoporous silica nanoparticles as pH-responsive delivery carrier.

In this paper, a facile and effective route has been developed for rapid synthesis of hollow mesoporous silica nanoparticles (HMSNs) by using tetradecyltrimethylammonium bromide (TTAB) as the porogen with the assistance of triethanolamine (TEA). The products were characterized by various techniques including TEM, SEM, BET, and FT-IR, etc. The HMSNs obtained possess spherical morphology, mesoporous channels and very high specific surface areas (1355m(2)g(-1)). According to the experimental results, a possible formation mechanism was discussed. Moreover, the ability of HMSNs as drug carrier was evaluated by selecting doxorubicin hydrochloride (DOX) as the model drug. The results indicated that HMSNs showed high loading capacity and controlled pH-responsive release behavior. Considering their unique nanostructures and porous properties, we expect the HMSNs prepared have more potential applications in various fields such as nanoreactors, cellular imaging, and biosensor.

Preparation of borneol loaded hollow mesoporous silica nanoparticles and effect on borneol volatility / 中国中药杂志

The hollow mesoporous silica nanoparticles (HMSNs) were prepared by hard template method, with a size of 300 nm and shell thickness of 25 nm. Borneol was loaded with solvent impregnation method in order to solve the stability problem of borneol in pharmaceutics, and the BET, TEM and FT-IR were used to characterize the HMSNs and the borneol-HMSNs drug delivery system. The optimal drug loading time, maximum drug loading capacity and the volatility of borneol were investigated. The results showed that HMSNs which were prepared at room temperature and neutral conditions had good sphericity, achieved high drug loading of borneol in a short time, and the drug loading was up to 74.04% within 6 hours; meanwhile, volatility of borneol in the system was greatly improved. This novel drug delivery system provides a new idea for wide application of borneol in the traditional Chinese medicine.