Preparation and evaluation of sirolimus sustained release tablets based on mesoporous silicon loaded self-microemulsion / 药学学报

Sirolimus self-microemulsion-mesoporous silicon sustained release tablets were prepared in order to improve the dissolution of the insoluble drug sirolimus and reduce its side effects. Firstly, sirolimus self-microemulsion was prepared and cured with mesoporous silicon. Secondly, the suitable excipients were selected according to the appearance, hardness and in vitro release rate. The sustained-release tablets with hydroxypropyl methylcellulose (HPMC) as skeleton material were prepared by powder direct pressing method, and the formulation was optimized by central composite design-response surface method to investigate the drug release in vitro. Finally, the pharmacokinetics was carried out in beagle dogs using the commercial sirolimus tablets as references. The final formulation of sustained-release tablets is as follows: 162 mg of sirolimus self-microemulsion-mesoporous silica (1∶1, w/w), 80 mg of HPMC K4M and 80 mg of carboxymethyl starch sodium, the microcrystalline cellulose is 168 mg. The results of in vitro release test showed that the self-made sustained-release tablets released slowly within 12 h, which conformed to the Ritger-Peppas model. The in vivo test results showed that compared with the commercial sirolimus tablets, the Cmax of the sustained-release tablets decreased by 49.47%, the Tmax of the sustained-release tablets was prolonged by 5.1 times, and the relative bioavailability was 105.81%. Sirolimus self-microemulsion-mesoporous silicon sustained-release tablets have good sustained-release effects in vitro and in vivo, which provides a reference for the solubilization of other insoluble drugs and the research and development of sustained-release preparations. Animal experiments and welfare processes were reviewed and approved by the Animal Ethics Committee of the 900TH Hospital of the Joint Logistics support Force.

Effect of nanoparticles of different stiffness combined with menthol/curcumol on mechanical properties of bEnd.3 cells / 中国中药杂志

This study aimed to investigate the effects of nanoparticles PLGA-NPs and mesoporous silicon nanoparticles(MSNs) of different stiffness before and after combination with menthol or curcumol on the mechanical properties of bEnd.3 cells. The particle size distributions of PLGA-NPs and MSNs were measured by Malvern particle size analyzer, and the stiffness of the two nanoparticles was quantified by atomic force microscopy(AFM). The bEnd.3 cells were cultured in vitro, and the cell surface morphology, roughness, and Young's modulus were examined to characterize the roughness and stiffness of the cell surface. The changes in the mechanical properties of the cells were observed by AFM, and the structure and expression of cytoskeletal F-actin were observed by a laser-scanning confocal microscope. The results showed that both nanoparticles had good dispersion. The particle size of PLGA-NPs was(98.77±2.04) nm, the PDI was(0.140±0.030), and Young's modulus value was(104.717±8.475) MPa. The particle size of MSNs was(97.47±3.92) nm, the PDI was(0.380±0.016), and Young's modulus value was(306.019±8.822) MPa. The stiffness of PLGA-NPs was significantly lower than that of MSNs. After bEnd.3 cells were treated by PLGA-NPs and MSNs separately, the cells showed fine pores on the cell surface, increased roughness, decreased Young's modulus, blurred and broken F-actin bands, and reduced mean gray value. Compared with PLGA-NPs alone, PLGA-NPs combined with menthol or curcumol could allow deepened and densely distributed surface pores of bEnd.3 cells, increase roughness, reduce Young's modulus, aggravate F-actin band breakage, and diminish mean gray value. Compared with MSNs alone, MSNs combined with menthol could allow deepened and densely distributed surface pores of bEnd.3 cells, increase roughness, reduce Young's modulus, aggravate F-actin band breakage, and diminish mean gray value, while no significant difference was observed in combination with curcumol. Therefore, it is inferred that the aromatic components can increase the intracellular uptake and transport of nanoparticles by altering the biomechanical properties of bEnd.3 cells.

Application research and design strategy on smart responsive mesoporous silica anti-tumor nanodelivery systems / 药学学报

Malignant tumors are major diseases that endanger human health. Due to their complex and variable microenvironment, most anti-tumor drugs cannot precisely reach the focal tissue and be released in a controlled manner. Intelligent responsive nano carriers have become a hot spot in the field of anti-tumor drug delivery systems. As an excellent nano material, mesoporous silica has the advantages of non-toxic, stable, adjustable pore volume and pore diameter, and easy functional modification on the surface. By virtue of its perceptive response to the tumor microenvironment or physiological changes, it can achieve the targeted drug release or controlled drug release of the drug delivery system in the tissue, making it an ideal carrier for intelligent response drug delivery system. In this paper, we review the design strategies and current research status of smart responsive anti-tumor drug delivery systems based on mesoporous silica, in order to provide a reference for the development of anti-tumor drug nanoformulations.

Preparation of mesoporous silica nanoparticles with different sizes and study on the correlation between size and toxicity / 药学学报

To investigate the crucial role of particle size in the biological effects of nanoparticles, a series of mesoporous silica nanoparticles (MSNs) were prepared with particle size gradients (50, 100, 150, 200 nm) with the traditional Stober method and adjusting the type and ratio of the silica source. The correlation between toxicity and size-caused biological effects were then further examined both in vitro and in vivo. The results indicated that the prepared MSNs had a uniform size, good dispersal, and ordered mesoporous structure. Hemolytic toxicity was found to be independent of particle size. At the cellular level, MSNs with smaller particle sizes were more readily internalized by cells, which initiated to more intense oxidative stress, therefor inducing higher cytotoxicity, and apoptosis rate. In vivo studies demonstrated that MSNs primarily accumulated in the liver and kidneys of mice. Pharmacokinetic analysis revealed that larger MSNs were eliminated more efficiently by the urinary system than smaller MSNs. The mice's body weight monitoring, blood tests, and pathological sections of major organs indicated good biocompatibility for MSNs of different sizes. Animal welfare and the animal experimental protocols were strictly consistent with related ethics regulations of Zhejiang Chinese Medical University. Overall, this study prepared MSNs with a particle size gradient to investigate the correlation between toxicity and particle size using macrophages and endothelial cells. The study also examined the biosafety of MSNs with different particle sizes in vivo and in vitro, which could help to improve the safety design strategy of MSNs for drug delivery systems.

Co-delivery of Tim-3 mAb and sorafenib enhanced chemoimmunotherapy for hepatocellular carcinoma using "responsive shell-peeling" mesoporous silica nanoparticles / 药学学报

Chemoimmunotherapy has attracted much attention as an emerging therapy pattern for the treatment of cancers. Exploring effective drug combination schemes and reasonable delivery methods remained the key issue in current research. Herein, we designed sorafenib (SF) and anti-Tim-3 monoclonal antibody (Tim-3 mAb) co-loaded MMP2-responsive mesoporous silica nanoparticles (ST-MSNs) for combined chemoimmunotherapy of hepatocellular carcinoma (HCC). The shell of ST-MSNs was fabricated by Tim-3 mAb through matrix metalloproteinase 2 (MMP2) sensitive peptides as "gatekeepers" to prevent drug release during the blood circulation. In tumor microenvironment, the high levels of MMP2 caused the responsive shedding of Tim-3 mAb, leading to the triggerred release of SF and Tim-3 mAb. Then, SF could be delivered to tumor cells and Tim-3 mAb could be delivered to T cells, respectively. In vivo tumor inhibition study results demonstrated that ST-MSNs can significantly enhance synergistic antitumor activity compared with sequential administration of free SF solution and Tim-3 mAb solution. Meanwhile, the expression of antitumor cytokines IFN-γ, IL-12 and the percentage of CD3+CD4+ cells, CD3+CD8+ cells in tumors were upregulated after the administration of ST-MSNs, demonstrating good immunomodulatory ability. In addition, within the dosage range, the ST-MSNs had low cytotoxicity and hemolysis, and no obvious tissue toxicity was observed. All animal experiments were performed in line with national regulations and approved by the Animal Experiments Ethical Committee of Shandong University. In conclusion, this study provided a promising drug combination of chemoimmunotherapy with good application prospects for clinical HCC treatment, and exhibited a potential drug carrier for clinical chemoimmunotherapy.

In vitro study of chlorhexidine acetate compound mesoporous silica orthodontic modified binder resin / 口腔疾病防治

Objective@#The antibacterial properties and bonding strength of 3M orthodontic adhesive resin modified by chlorhexidine acetate (CHA) composite mesoporous silica were investigated.@*Methods@# CHA with different mass fractions was encapsulated in mesoporous silica nanoparticles (MSNs) (denoted CHA@MSNs). Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were used to characterize the samples. The 3M Z350XT flow resin was divided into 4 groups: group A: 3M+CHA@MSNs (0%); group B: 3M+CHA@MSNs (3%); group C: 3M+CHA@MSNs (5%); and group D: 3M+CHA@MSNs (6.4%), with mass scores of 0%, 3%, 5%, and 6.4%, respectively. The shear strength of the modified adhesive was tested by a universal electronic material testing machine, the adhesive residue was observed by a 10 × magnifying glass, and the adhesive Remnant index (ARI) was calculated. The four groups of modified adhesives were cultured with Streptococcus mutans. The OD540 value of the bacterial solution was measured by a spectrophotometer, and the amount of plaque attachment was observed by scanning electron microscopy to evaluate the antibacterial performance of the adhesives.@*Results@#Infrared spectroscopic analysis of CHA@MSNs showed that CHA was successfully loaded onto MSNs. Under scanning electron microscopy, it could be seen that, after Cha was combined with MSNs, the structure of MSNs changed, as the boundary was fuzzy and aggregated into a layered structure. A comparison of shear strength revealed a statistically significant difference between the groups containing CHA@MSNs and the groups without CHA@MSNs (P<0.05). The value of the shear strength in group D decreased the most, while there was no statistically significant difference between group B and group C (P > 0.05). There was no statistical significance across all groups (P > 0.05), suggesting that the addition of CHA@MSNs had little effect on the bracket shedding. The OD540 value of bacterial fluid indicated that the difference among groups A, B and C was statistically significant (P < 0.05), and the antibacterial effect of group C was the best; there was no statistically significant difference between group C and group D (P > 0.05).@*Conclusions@#Therefore, adding 5% CHA@MSN antibacterial agent significantly improved the antibacterial effect and did not affect the bond strength.

Inhaled curcumin mesoporous polydopamine nanoparticles against radiation pneumonitis

Radiation therapy is an effective method to kill cancer cells and shrink tumors using high-energy X-ray or γ-ray. Radiation pneumonitis (RP) is one of the most serious complications of radiation therapy for thoracic cancers, commonly leading to serious respiratory distress and poor prognosis. Here, we prepared curcumin-loaded mesoporous polydopamine nanoparticles (CMPN) for prevention and treatment of RP by pulmonary delivery. Mesoporous polydopamine nanoparticles (MPDA) were successfully synthesized with an emulsion-induced interface polymerization method and curcumin was loaded in MPDA via π‒π stacking and hydrogen bonding interaction. MPDA owned the uniform spherical morphology with numerous mesopores that disappeared after loading curcumin. More than 80% curcumin released from CMPN in 6 h and mesopores recovered. CMPN remarkably protected BEAS-2B cells from γ-ray radiation injury by inhibiting apoptosis. RP rat models were established after a single dose of 15 Gy 60Co γ-ray radiation was performed on the chest area. Effective therapy of RP was achieved by intratracheal administration of CMPN due to free radical scavenging and anti-oxidation ability, and reduced proinflammatory cytokines, high superoxide dismutase, decreased malondialdehyde, and alleviated lung tissue damages were observed. Inhaled CMPN paves a new avenue for the treatment of RP.

Chiral mesoporous silica nano-screws as an efficient biomimetic oral drug delivery platform through multiple topological mechanisms

In the microscale, bacteria with helical body shapes have been reported to yield advantages in many bio-processes. In the human society, there are also wisdoms in knowing how to recognize and make use of helical shapes with multi-functionality. Herein, we designed atypical chiral mesoporous silica nano-screws (CMSWs) with ideal topological structures (e.g., small section area, relative rough surface, screw-like body with three-dimension chirality) and demonstrated that CMSWs displayed enhanced bio-adhesion, mucus-penetration and cellular uptake (contributed by the macropinocytosis and caveolae-mediated endocytosis pathways) abilities compared to the chiral mesoporous silica nanospheres (CMSSs) and chiral mesoporous silica nanorods (CMSRs), achieving extended retention duration in the gastrointestinal (GI) tract and superior adsorption in the blood circulation (up to 2.61- and 5.65-times in AUC). After doxorubicin (DOX) loading into CMSs, DOX@CMSWs exhibited controlled drug release manners with pH responsiveness in vitro. Orally administered DOX@CMSWs could efficiently overcome the intestinal epithelium barrier (IEB), and resulted in satisfactory oral bioavailability of DOX (up to 348%). CMSWs were also proved to exhibit good biocompatibility and unique biodegradability. These findings displayed superior ability of CMSWs in crossing IEB through multiple topological mechanisms and would provide useful information on the rational design of nano-drug delivery systems.

Recent progress in magnetic nanoparticles and mesoporous materials for enzyme immobilization: an update / Progresso recente em nanopartículas magnéticas e materiais mesoporosos para imobilização de enzimas: uma atualização

Enzymes immobilized onto substrates with excellent selectivity and activity show a high stability and can withstand extreme experimental conditions, and their performance has been shown to be retained after repeated uses. Applications of immobilized enzymes in various fields benefit from their unique characteristics. Common methods, including adsorption, encapsulation, covalent attachment and crosslinking, and other emerging approaches (e.g., MOFs) of enzyme immobilization have been developed mostly in recent years. In accordance with these immobilization methods, the present review elaborates the application of magnetic separable nanoparticles and functionalized SBA-15 and MCM-41 mesoporous materials used in the immobilization of enzymes.

Enzimas imobilizadas em substratos com excelente seletividade e atividade apresentam alta estabilidade e podem suportar condições experimentais extremas, e seu desempenho foi mantido após repetidos usos. As aplicações de enzimas imobilizadas em vários campos se beneficiam de suas características únicas. Métodos comuns, incluindo adsorção, encapsulamento, ligação covalente e reticulação, e outras abordagens emergentes (por exemplo, MOFs) de imobilização de enzima, foram desenvolvidos principalmente nos últimos anos. De acordo com esses métodos de imobilização, a presente revisão elabora a aplicação de nanopartículas magnéticas separáveis e materiais mesoporosos funcionalizados SBA-15 e MCM-41 usados na imobilização de enzimas.

Recent progress in magnetic nanoparticles and mesoporous materials for enzyme immobilization: an update

Abstract Enzymes immobilized onto substrates with excellent selectivity and activity show a high stability and can withstand extreme experimental conditions, and their performance has been shown to be retained after repeated uses. Applications of immobilized enzymes in various fields benefit from their unique characteristics. Common methods, including adsorption, encapsulation, covalent attachment and crosslinking, and other emerging approaches (e.g., MOFs) of enzyme immobilization have been developed mostly in recent years. In accordance with these immobilization methods, the present review elaborates the application of magnetic separable nanoparticles and functionalized SBA-15 and MCM-41 mesoporous materials used in the immobilization of enzymes.

Resumo Enzimas imobilizadas em substratos com excelente seletividade e atividade apresentam alta estabilidade e podem suportar condições experimentais extremas, e seu desempenho foi mantido após repetidos usos. As aplicações de enzimas imobilizadas em vários campos se beneficiam de suas características únicas. Métodos comuns, incluindo adsorção, encapsulamento, ligação covalente e reticulação, e outras abordagens emergentes (por exemplo, MOFs) de imobilização de enzima, foram desenvolvidos principalmente nos últimos anos. De acordo com esses métodos de imobilização, a presente revisão elabora a aplicação de nanopartículas magnéticas separáveis e materiais mesoporosos funcionalizados SBA-15 e MCM-41 usados na imobilização de enzimas.

Recent progress in magnetic nanoparticles and mesoporous materials for enzyme immobilization: an update / Progresso recente em nanopartículas magnéticas e materiais mesoporosos para imobilização de enzimas: uma atualização

Enzymes immobilized onto substrates with excellent selectivity and activity show a high stability and can withstand extreme experimental conditions, and their performance has been shown to be retained after repeated uses. Applications of immobilized enzymes in various fields benefit from their unique characteristics. Common methods, including adsorption, encapsulation, covalent attachment and crosslinking, and other emerging approaches (e.g., MOFs) of enzyme immobilization have been developed mostly in recent years. In accordance with these immobilization methods, the present review elaborates the application of magnetic separable nanoparticles and functionalized SBA-15 and MCM-41 mesoporous materials used in the immobilization of enzymes.

Enzimas imobilizadas em substratos com excelente seletividade e atividade apresentam alta estabilidade e podem suportar condições experimentais extremas, e seu desempenho foi mantido após repetidos usos. As aplicações de enzimas imobilizadas em vários campos se beneficiam de suas características únicas. Métodos comuns, incluindo adsorção, encapsulamento, ligação covalente e reticulação, e outras abordagens emergentes (por exemplo, MOFs) de imobilização de enzima, foram desenvolvidos principalmente nos últimos anos. De acordo com esses métodos de imobilização, a presente revisão elabora a aplicação de nanopartículas magnéticas separáveis e materiais mesoporosos funcionalizados SBA-15 e MCM-41 usados na imobilização de enzimas.

pH-sensitive and bubble-generating mesoporous silica-based nanoparticles for enhanced tumor combination therapy

Chemotherapy has been a major option in clinic treatment of malignant tumors. However, single chemotherapy faces some drawbacks, such as multidrug resistance, severe side effects, which hinder its clinic application in tumor treatment. Multifunctional nanoparticles loading with chemotherapeutic agent and photosensitizer could be a promising way to efficiently conduct tumor combination therapy. In the current study, a novel pH-sensitive and bubble-generating mesoporous silica-based drug delivery system (denoted as M(a)D@PI-PEG-RGD) was constructed. Ammonium bicarbonate (NH

Construction of a curcumin-siRNA co-delivery system based on mesoporous silica and its effect on M2-type polarization of macrophages / 口腔疾病防治

Objective @#To fabricate a co-delivery system of curcumin (CUR) and siRNA based on mesoporous silica nanoparticles (MSN) and investigate its potential application in inducing macrophage M2 polarization.@*Methods@# MSNs were synthesized using the conventional sol-gel method. The interior mesochannels were occupied by small-molecule CUR, while the exterior surface was adsorbed by cationic polymeric polyethyleneimine (PEI) to link the negatively charged siRNA molecules to formulate the (CUR@MSN)PEI/siRNA co-delivery system. The formulation process was monitored by transmission electron microscopy(TEM). The MTT assay was used to evaluate the cytotoxicity in RAW264.7 cells under various concentrations of nanoparticles. Confocal laser scanning microscopy and TEM were used to observe cell internalization using FAM-labeled siRNA. GAPDH-targeting siRNA was used to prepare nanoparticles and then was transfected into RAW264.7 cells to observe the silencing efficiency of target genes. The knockdown efficiency was examined by real-time quantitative PCR. The related control groups were untreated cells, CUR delivery only and the co-delivery of CUR and siRNA negative control. By loading miRNA-130a-3p antisense oligonucleotide (ASO) to transfect RAW264.7 cells, the effects on the polarization of macrophages were observed. The M2 polarization marker arginase 1 (Arg-1) was measured by western blotting. The related control groups were untreated cells, CUR delivery only and co-delivery of CUR and miRNA negative control. @* Results @# The (CUR@MSN)PEI/siRNA co-delivery system was successfully formulated. The nanoparticles exhibited dose-dependent cytotoxicity, and the cell viability was maintained over 90% when the nanoparticle concentration was less than 10 μg/mL. A high cell uptake efficiency was observed, and the target gene knockdown efficiency was greater than 80% (P < 0.05 vs. all the other groups). The CUR delivery-only group and co-delivery of the CUR-and miRNA-negative control group improved Arg-1 expression ~ 3-fold (P < 0.05 vs. untreated cells). Using the co-delivery of CUR and ASO, synergistic effects were obtained, and Arg-1 expression was increased ~ 8-fold (P < 0.05 vs. all the other groups).@*Conclusion @#The CUR-siRNA co-delivery system can effectively transfect macrophages and synergistically induce M2 polarization.

Mesoporous silica nanoparticles for bone tissue engineering / 中国骨伤

As a new potential bone graft material, tissue engineered bone effectively compensates for the defects of today's bone repair materials. Meanwhile, mesoporous silica nanomaterials(MSNs) have been widely recognized due to their large specific surface area, good biocompatibility, and capability of further processing and modification. They have promising application prospects in bone tissue engineering. For the basic scientific research results that have been carried out in the early stage, the basic characteristics of mesoporous silica nano biomaterials and their application advantages, research status and development prospects in bone tissue engineering are reviewed. As for the research status, there are two aspects--as a carrier or as a component of engineering scaffolds. For the first aspect, different kinds of loaded drugs and different loading methods are reviewed. For the second, microstructure and mechanical properties of various complex scaffolds containing MSNs and the molecular and cellular behavior of seeded cells on these scaffolds are reviewed. The research of MSNs in bone cements and metal ions doped MSNs in bone tissue engineering are also included. The future development of MSNs in bone tissue engineering is also discussed.

The use of a new calcium mesoporous silica nanoparticle versus calcium and/or fluoride products in reducing the progression of dental erosion

Abstract Objective There is increasingly common the consumption more times a day of foods and acidic drinks in the diet of the population. The present study aimed to evaluate and compare the effects of a calcium mesoporous silica nanoparticle single application of other calcium and/or fluoride products in reducing the progression of dental erosion. Methodology Half of the eroded area was covered of 60 blocks of enamel, after which the block was submitted to the following treatments: (Ca2+-MSN), casein phosphopeptide-amorphous calcium phosphate (CPP-ACP); CPP-ACP/F-(900 ppm F−); titanium tetrafluoride (TiF4 1%) (positive control); sodium fluoride (NaF 1.36%) (positive control); and Milli-Q® water (negative control) before being submitted to a second erosive challenge. A surface analysis was performed via a three-dimensional (3D) noncontact optical profilometry to assess the volumetric roughness (Sa) and tooth structure loss (TSL) and and through scanning electron microscopy (MEV). An analysis of variance (ANOVA) and Tukey's test were performed. Results Regarding Sa, all experimental groups exhibited less roughness than the control (p<0.05). The TSL analysis revealed that the Ca2+-MSN and NaF groups were similar (p>0.05) and more effective in minimizing tooth loss compared with the other groups (p<0.05). Conclusions The Ca2+-MSN and NaF treatments were superior compared with the others and the negative control.

Urea incorporated into ordered mesoporous silica for potential cosmetic application

Urea's thermal instability and burning on sensitive skin can cause problems for cosmetic formulations. To overcome these drawbacks, urea was incorporated into ordered mesoporous silica (SBA-15). SBA-15 was synthesized using tetraethyl orthosilicate and Pluronic® P123 in an acid medium. Urea (20 wt.%) was incorporated into calcined SBA-15 by the incipient wetness impregnation method. Several techniques were used to characterize the samples. Skin hydration and transepidermal water loss were measured using Corneometer® CM 825 PC and Tewameter® 300 TM. Results showed that the structural properties of SBA-15Urea were similar to pure SBA-15, indicating that SBA-15 remained structured even after urea incorporation. Nitrogen physisorption data showed the volume and surface area of the pores in SBA-15Urea were much lower than those in SBA-15, demonstrating that urea was deposited inside the mesopores. In vivo moisturization studies revealed that SBA-15Urea was not able to reduce transepidermal water loss compared to the other products and control, while forming a non-occlusive surface film on the skin. We conclude that incorporation of urea in the pores of the inorganic SBA-15 matrix is a promising approach to enhancing its stability and providing a prolonged moisturizing effect.

Construction and in Vitro Study of Glioma-Targeted Cell Membrane Biomimetic Delivery System / 中国药学杂志

OBJECTIVE: To construct a biomimetic delivery system (U251/MSN-DOX), and assess its application of glioma targeted therapy. METHODS: U251 cell membrane was coated on the surface of mesoporous silica nanoparticles(MSN) by co-extrusion to prepare cell membrane biomimetic nanoparticles U251/MSN-DOX. The particle size, potential and morphology were characterized. The physical characteristics, loading content (LC) and encapsulation efficiency (EE) of these nanoparticles were determined. Their toxicity of normal cells was investigated. Their cellular uptake of different formulations in U251 was studied by flow cytometry and fluorescence confocal microscope. Additionally, we assessed the transmembrane transport efficiency of nanoparticles via in vitro BBB. RESULTS: The cell membrane-coated nanoparticles U251/MSN were spherical, and a distinct "core-shell" structure could be observed. The particle size was (135.70±3.85) nm, the LC was (18.57±2.17)%, and the EE was (64.99±2.52)%. The cell experiment showed that U251/MSN had low cytotoxicity and U251/MSN-DOX exhibited stronger cellular uptake ability and BBB transporting efficiency. CONCLUSION: The glioma cell membrane can be coated on the surface of MSN to construct biomimetic nanoparticles U251/MSN. The biomimetic nanoparticles not only are capable of targeting the homologous tumor cells, but also show the enhanced ability to penetrate BBB, which indicate potential applications in the field of tumor targeted drug delivery especially in brain tumor.

Seleção de carvões ativados para adsorção de microcistinas / Selection of activated carbons for adsorption of microcystins

RESUMO A presença das cianobactérias é uma das grandes preocupações para o tratamento de água, uma vez que esses microrganismos podem ser produtores de metabólitos tóxicos, como as microcistinas (MCs), que não são efetivamente removidas no tratamento usualmente empregado de ciclo completo. Para a remoção dessas toxinas, pode-se, de forma complementar, utilizar adsorvedores como o carvão ativado (CA), que apresenta eficiência variada, em função de suas características. Este trabalho teve como objetivo fornecer subsídios técnicos e científicos para a seleção de carvões ativados pulverizados (CAPs) e carvões ativados granulares (CAGs) como adsorvedores de MCs. Para tanto, foi realizado, primeiramente, um experimento de seleção de CAs com maior capacidade adsortiva para MCs, em escala de bancada. Em seguida, para os CAPs e CAGs selecionados, foi realizada caracterização complementar para a distribuição de volume específico em função do tamanho do poro. Posteriormente, foram elaboradas isotermas de adsorção de Freundlich e curvas de ruptura. Pôde-se constatar que, dentre os CAs amostrados, os importados apresentaram maior capacidade adsortiva para MCs do que os nacionais. Além disso, foi possível concluir que a escolha do CA pode ser determinada pelos parâmetros índice de azul de metileno (IAM), volume de mesoporos e coeficiente Kf, associados aos resultados do experimento de seleção, considerado uma ferramenta técnica alternativa de simples aplicação e suficiente para esse fim.

ABSTRACT The presence of cyanobacteria is a major concern for water treatment, since these microorganisms can be toxic metabolic producers, such as microcystins (MCs), which are not effectively removed in the usually employed full cycle treatment. In order to remove these toxins, it is possible to use absorbers such as activated carbon (AC), which presents a varied efficiency, depending on its characteristics. The general objective of this research was to provide technical and scientific subsidies for the selection of powdered activated carbons (PACs) and granular activated carbons (GACs) in relation to the adsorption of microcystins. A bench scale experiment was carried out to select activated carbons with higher adsorptive capacity for microcystins. Then, for the selected PACs and GACs, complementary characterization was performed for the specific volume distribution as function of pore size and, afterwards, Freundlich adsorption isotherms and breakthrough curves were elaborated. It was possible to verify that among the sampled activated carbons, the imported ones presented greater adsorption capacity for microcystins in relation to the nationals. In addition, it was possible to conclude that the selection of an activated carbon can be done regarding methylene blue index (MBI) parameters, volume of mesoporous and Kf, associated to the selection experiment's results, considered an alternative technical tool of simple application and sufficient for this purpose.

Delivery of miR-375 and doxorubicin hydrochloride by lipid bilayer coated hollow mesoporous silica nanoparticles for liver cancer therapy / 药学学报

This study was designed to prepare a novel lipid bilayer coated hollow mesoporous silica nanocarrier for co-delivery of gene drugs and chemotherapeutic drugs to enhance the inhibitory activity of antitumor drugs in hepatoma cells. Hollow mesoporous silica was synthesized by modified StÖber method. Lipid-fusion principle was used to prepare lipid-hollow co-loaded doxorubicin (DOX) and miR-375 (LHMSN-DOX/miR-375). Meanwhile, the morphology, particle size, surface potential, drug loading and release were characterized in vitro. The inhibition of cell proliferation, cell migration and invasion was then evaluated. The results indicated that the core-shell structure of LHMSN-DOX/miR-375 was clear with an intact outer lipid membrane and an ordered internal HMSN mesoporous structure. The drug release amount was pH responsive while the drug was rapidly released under simulated intracellular acidic conditions relative to normal physiological environment. Compared with free DOX, LHMSN-DOX/miR-375 can deliver DOX and miR-375 to liver cancer cells and inhibit the proliferation, migration and invasion of cells more effectively.

Advances in the mesoporous silica-based reactive oxygen species controlled-release nanosystem and its anti-tumor application / 上海交通大学学报（医学版）

Until now, great progress has been made in anti-tumor therapy. A series of novel anti-tumor drugs, such as molecular targeted drugs and monoclonal antibodies, have been emerging one after another, which have benefited a great number of tumor patients in different degrees. However, there are still many dilemmas in clinical anti-tumor therapy at present, for instance, obvious side effects, tumor resistance and so on. In recent years, the nano drug delivery system with mesoporous silica as the carrier has overcome many flaws of traditional anti-tumor treatment to a certain extent, especially the mesoporous silica nanosystem for controlling reactive oxygen species generation which has excellent tumor targeting property and biocompatibility, and minimal injury effects on normal tissue cells. So it has been regarded as one of the most promising agents in clinical application by playing significant anti-tumor roles through multiple approaches. This paper reviews this kind of potent nanosystem and its application to anti-tumor therapy.