Hollow Mesoporous Silica Nanoparticles Research Articles

Smart and Sustainable Crop Protection: Design and Evaluation of a Novel α-Amylase-Responsive Nanopesticide for Effective Pest Control.

In this study, an α-amylase-responsive controlled-release formulation was developed by capping polydopamine onto β-cyclodextrin-modified abamectin-loaded hollow mesoporous silica nanoparticles. The prepared Aba@HMS@CD@PDA were subjected to characterization using various analytical techniques. The findings revealed that Aba@HMS@CD@PDA, featuring a loading rate of 18.8 wt %, displayed noteworthy release behavior of abamectin in the presence of α-amylase. In comparison to abamectin EC, Aba@HMS@CD@PDA displayed a significantly foliar affinity and improved rainfastness on lotus leaves. The results of field trail demonstrated a significantly higher control efficacy against Spodoptera litura Fabricius compared to abamectin EC at all concentrations after 7, 14, and 21 days of spaying, showcasing the remarkable persistence of Aba@HMS@CD@PDA. These results underscore the potential of Aba@HMS@CD@PDA as a novel and persistently effective strategy for sustainable on-demand crop protection. The application of nanopesticides can enhance the effectiveness and efficiency of pesticide utilization, contributing to more sustainable agricultural practices.

Double-layer hollow mesoporous silica nanoparticles for ultrasound-guided photodynamic treatment.

Cervical carcinoma persists as a major global public health burden. While conventional therapeutic modalities inevitably cause ablation of adjacent non-tumorous tissues, photodynamic therapy (PDT) offers a targeted cytotoxic strategy through a photosensitizing agent (PS). However, the hydrophobicity and lack of selective accumulation of promising PS compounds such as zinc(II) phthalocyanine (ZnPc) impedes their clinical translation as standalone agents. The present study sought to incorporate ZnPc within double-layer hollow mesoporous silica nanoparticles (DHMSN) as nanocarriers to enhance aqueous dispersibility and tumor specificity. Owing to their compartmentalized design, the hollow mesoporous silica nanoparticles (HMSN) demonstrated enhanced ultrasonic imaging contrast. Combined with the vaporization of the perfluorocarbon perfluoropentane (PFP), the HMSN-encapsulated ZnPc enabled real-time ultrasound monitoring of PDT treatment. In vivo, the innate thermal energy induced vaporization of the DHMSN-carried PFP to significantly amplify ultrasound signals from the tumor site. Results demonstrated biocompatibility, efficient PFP microbubble generation, and robust photocatalytic activity. Collectively, this investigation establishes ultrasound-guided PDT utilizing multi-layer HMSN as a targeted therapeutic strategy for cervical malignancies with mitigated toxicity.

Hollow Mesoporous Silica Nanoparticles as a New Nanoscale Resistance Inducer for Fusarium Wilt Control: Size Effects and Mechanism of Action.

In agriculture, soil-borne fungal pathogens, especially Fusarium oxysporum strains, are posing a serious threat to efforts to achieve global food security. In the search for safer agrochemicals, silica nanoparticles (SiO2NPs) have recently been proposed as a new tool to alleviate pathogen damage including Fusarium wilt. Hollow mesoporous silica nanoparticles (HMSNs), a unique class of SiO2NPs, have been widely accepted as desirable carriers for pesticides. However, their roles in enhancing disease resistance in plants and the specific mechanism remain unknown. In this study, three sizes of HMSNs (19, 96, and 406 nm as HMSNs-19, HMSNs-96, and HMSNs-406, respectively) were synthesized and characterized to determine their effects on seed germination, seedling growth, and Fusarium oxysporum f. sp. phaseoli (FOP) suppression. The three HMSNs exhibited no side effects on cowpea seed germination and seedling growth at concentrations ranging from 100 to 1500 mg/L. The inhibitory effects of the three HMSNs on FOP mycelial growth were very weak, showing inhibition ratios of less than 20% even at 2000 mg/L. Foliar application of HMSNs, however, was demonstrated to reduce the FOP severity in cowpea roots in a size- and concentration-dependent manner. The three HMSNs at a low concentration of 100 mg/L, as well as HMSNs-19 at a high concentration of 1000 mg/L, were observed to have little effect on alleviating the disease incidence. HMSNs-406 were most effective at a concentration of 1000 mg/L, showing an up to 40.00% decline in the disease severity with significant growth-promoting effects on cowpea plants. Moreover, foliar application of HMSNs-406 (1000 mg/L) increased the salicylic acid (SA) content in cowpea roots by 4.3-fold, as well as the expression levels of SA marker genes of PR-1 (by 1.97-fold) and PR-5 (by 9.38-fold), and its receptor gene of NPR-1 (by 1.62-fold), as compared with the FOP infected control plants. Meanwhile, another resistance-related gene of PAL was also upregulated by 8.54-fold. Three defense-responsive enzymes of POD, PAL, and PPO were also involved in the HMSNs-enhanced disease resistance in cowpea roots, with varying degrees of reduction in activity. These results provide substantial evidence that HMSNs exert their Fusarium wilt suppression in cowpea plants by activating SA-dependent SAR (systemic acquired resistance) responses rather than directly suppressing FOP growth. Overall, for the first time, our results indicate a new role of HMSNs as a potent resistance inducer to serve as a low-cost, highly efficient, safe and sustainable alternative for plant disease protection.

Size Tuning of Mesoporous Silica Adjuvant for One-Shot Vaccination with Long-Term Anti-Tumor Effect.

Despite recent clinical successes in cancer immunotherapy, it remains difficult to initiate a long-term anti-tumor effect. Therefore, repeated administrations of immune-activating agents are generally required in most cases. Herein, we propose an adjuvant particle size tuning strategy to initiate a long-term anti-tumor effect by one-shot vaccination. This strategy is based on the size-dependent immunostimulation mechanism of mesoporous silica particles. Hollow mesoporous silica (HMS) nanoparticles enhance the antigen uptake with dendritic cells around the immunization site in vivo. In contrast, hierarchically porous silica (HPS) microparticles prolong cancer antigen retention and release in vivo. The size tuning of the mesoporous silica adjuvant prepared by combining both nanoparticles and microparticles demonstrates the immunological properties of both components and has a long-term anti-tumor effect after one-shot vaccination. One-shot vaccination with HMS-HPS-ovalbumin (OVA)-Poly IC (PIC, a TLR3 agonist) increases CD4+ T cell, CD8+ T cell, and CD86+ cell populations in draining lymph nodes even 4 months after vaccination, as well as effector memory CD8+ T cell and tumor-specific tetramer+CD8+ T cell populations in splenocytes. The increases in the numbers of effector memory CD8+ T cells and tumor-specific tetramer+CD8+ T cells indicate that the one-shot vaccination with HMS-HPS-OVA-PIC achieved the longest survival time after a challenge with E.G7-OVA cells among all groups. The size tuning of the mesoporous silica adjuvant shows promise for one-shot vaccination that mimics multiple clinical vaccinations in future cancer immunoadjuvant development. This study may have important implications in the long-term vaccine design of one-shot vaccinations.

Bioinspired Hollow Mesoporous Silica Nanoparticles Coating on Titanium Alloy with Hierarchical Structure for Modulating Cellular Functions

Bioinspired Hollow Mesoporous Silica Nanoparticles Coating on Titanium Alloy with Hierarchical Structure for Modulating Cellular Functions

Fabrication of folic acid-modified bovine serum albumin cloaked dual-drug loaded hollow mesoporous silica nanoparticles for pH-responsive and targeted delivery of gastric cancer therapy

Combination therapy is a highly successful way to address the limitations of using a single treatment method and improve therapy's overall efficacy. In this study, we developed a unique hollow mesoporous silica nanoparticle (HMSN) coated with folic acid (FA)-modified bovine serum albumin (FA-BSA). This nanoparticle, referred to as HFB, was designed to target cancer cells and release dual therapeutic drugs, Indocyanine green (ICG) and Paclitaxel (PTX), in response to specific stimuli termed as HFB@IP. The BSA protein acts as a “gatekeeper” to prevent early drug releases and cargo leakage by detaching from BSA in reaction to GSH. The FA facilitates the targeted transport of the drug into cancer cells that express folate receptors (FR), enhancing the effectiveness of chemo-photodynamic treatment (PDT). The drug nanocarrier demonstrated in vitro pH/redox-triggered drug release from HFB@IP due to breaking the imine bonds between aldehyde-functionalized HMSN (CHO-HMSN) and FA-BSA with the disulfide bond inside BSA. In addition, various biological assessments, including cell uptake experiments, demonstrated that HFB@IP effectively targets SGC-7901 cells and induces apoptosis in vitro. Further, it exhibits remarkable efficiency in synergistically killing cancer cells through chemo-photodynamic therapy, as indicated by a combination index (CI) of 0.328. The results showed that combining HMSN with biodegradable stimuli-responsive BSA molecules could offer a promising approach for precise chemo-photodynamic therapy in treating gastric cancer, allowing for the controlled release of drugs as necessary.

Multilayer pH-responsive hollow mesoporous silica nanoparticles with charge reversal for drug delivery and real-time monitoring by fluorescence

Drug delivery systems (DDSs) with charge reversal could simultaneously achieve long circulation time and enhanced cellular internalization efficiency. Here, hollow mesoporous silica nanoparticles (HMSNs) were used as the basic stuff for encapsulating doxorubicin (DOX), positive-charged chitosan (CS) was grafted on the surface of HMSNs, and negatively charged carboxyl-rich carbon dots (CDs) were coated on the outer layer of CS through non-covalent bonds. The new drug delivery vehicles with 56.6 % drug-loading content were prepared, named as CDs-CS/HMSNs@DOX. Tumor environment with a slightly acidic state could trigger the disruption of the non-covalent bonds, followed by the detachment of CDs, making the negatively charged CDs-CS/HMSNs@DOX change into positively charged CS/HMSNs@DOX. CS swelling reaction also happened in slightly acidic conditions. Both the CS swelling and the detachment of CDs resulted in the exposure of mesopore and drug release. Fluorescence recovery of detached CDs could be used to monitor the release of DOX in real-time. The multilayer pH-responsive nano carries with charge reversal and real-time monitoring demonstrated broad application prospects.

MnO2 modified hollow mesoporous silica nanoparticles for enhanced chemodynamic therapy

Chemodynamic therapy (CDT) exert its influence in tumor therapy by disrupting the redox equilibrium within tumor cells, inciting a cascade of oxidative stress reactions, and hamper the proliferation and survival of tumor cells. Harnessing the abundant expression of glutathione (GSH) at tumor sites, we devised a drug delivery system based on hollow mesoporous silica nanoparticles (HMSN), enveloped by an outer layer composed of MnO2. Upon exposure to GSH, MnO2 undergoes degradation into Mn2+, engaging in a Fenton reaction with the loaded dihydroartemisinin (DHA) within HMSN and intracellular H2O2. This intricate interplay results in the generation of reactive oxygen species (ROS). In vivo antitumor experiments showcased the significant efficacy of HMSN@DHA@MnO2 in restraining subcutaneous tumor growth in nude mice. Culminating in a striking tumor inhibition rate of 52.6%. The targeted methodology of this nanocarrier system holds substantial promise in advancing novel and efficacious strategies within the filed of tumor therapy.

PH-Responsive Pesticide-Loaded Hollow Mesoporous Silica Nanoparticles with ZnO Quantum Dots as a Gatekeeper for Control of Rice Blast Disease.

Nanotechnology-enabled pesticide delivery systems have been widely studied and show great prospects in modern agriculture. Nanodelivery systems not only achieve the controlled release of agrochemicals but also possess many unique characteristics. This study presents the development of a pH-responsive pesticide nanoformulation utilizing hollow mesoporous silica nanoparticles (HMSNs) as a nanocarrier. The nanocarrier was loaded with the photosensitive pesticide prochloraz (Pro) and then combined with ZnO quantum dots (ZnO QDs) through electrostatic interactions. ZnO QDs serve as both the pH-responsive gatekeeper and the enhancer of the pesticide. The results demonstrate that the prepared nanopesticide exhibits high loading efficiency (24.96%) for Pro. Compared with Pro technical, the degradation rate of Pro loaded in HMSNs@Pro@ZnO QDs was reduced by 26.4% after 24 h ultraviolet (UV) exposure, indicating clearly improved photostability. In a weak acidic environment (pH 5.0), the accumulated release of the nanopesticide after 48 h was 2.67-fold higher than that in a neutral environment. This indicates the excellent pH-responsive characteristic of the nanopesticide. The tracking experiments revealed that HMSNs can be absorbed by rice leaves and subsequently transported to other tissues, indicating their potential for effective systemic distribution and targeted delivery. Furthermore, the bioactivity assays confirmed the fungicidal efficacy of the nanopesticide against rice blast disease. Therefore, the constructed nanopesticide holds great prospect in nanoenabled agriculture, offering a novel strategy to enhance pesticide utilization.

A modified hard-templating for hollow mesoporous silica nanoparticles with suitable particle size and shortened synthetic time

Hollow mesoporous silica nanoparticles (HMSN), a member of mesoporous silica family synthesized mainly with har-templating method, has gained great interest in pharmaceutical applications due to their impress characteristics such as good biocompatibility, large specific surface area and pore volume, controllable particle size, large cavity for cargo loading, and flexible surface functionalization possibilities. However, controlling the optimal particle size and shortening the synthesis time have been the issues of HMSN synthesis that needed to be improved. In this study, HMSN was synthesized using hard-templating with some modifications to shorten the synthesis time and adjust the particle size to nearly 100 nm. The obtained HMSN particles showed high uniform morphology as spheres with hollow core-mesoporous shell structure, having the particle diameter of about 90 nm, the hollow diameter of about 68 nm, and the mesoporous shell thickness of about 11 nm. The total time for the main reactions was shortened by more than half from 21 hours to 9 hours. Additionally, MTT assays revealed that the synthesized HMSN was biocompatible material. This modified hard-template method with shorter synthesis time and nearly 100 nm obtained particle diameter would be meaningful for scientific research and industrial scale production.

CaCO3-coated hollow mesoporous silica nanoparticles for pH-responsive fungicides release

CaCO3-coated hollow mesoporous silica nanoparticles for pH-responsive fungicides release

Tumor microenvironment-activated hollow vanadium-based nanoplatform for precise therapy of lung cancer through synergistically reversing cisplatin resistance

The resistance and side effect of cisplatin (CDDP) were still great challenges for highly efficient therapy of lung cancer in clinic. The studies indicated that the CDDP resistance mainly involved GSH-mediated inactivation and the damaged DNA repair. Herein, a novel vanadium-based nanoplatform was designed via platelet-derived growth factor receptor-β (PDGFR-β)-recognizing cyclic peptide (PDGFB)-labeled liposomes coating onto the hollow vanadium-doped mesoporous silica nanoparticle (HVMSN) loaded Pt (IV) prodrugs (pLi-HVMSN-Pt). This nanoplatform actively targeted tumor tissue, and then effectively responded to weakly acidic and high GSH of tumor microenvironment, making Pt (IV) prodrugs and vanadium ions be precisely delivered and intelligently released. Moreover, the vanadium ions significantly downregulated the expression of glutamyl cysteine ligase (GCL) and excision repair cross-complementing 1 (ERCC1), which inhibited the synthesis of GSH in cells and the damaged DNA repair. These synergistic actions dramatically increased the sensitivity of tumor cells to Pt-based drug, and then reversed CDDP resistance. Furthermore, in vivo experiment results demonstrated highly efficient suppression of tumor growth induced by the pLi-HVMSN-Pt. Therefore, this work provided a novel strategy for reversing CDDP-resistance and the precise therapy of lung cancer.

Inhaled immunoantimicrobials for the treatment of chronic obstructive pulmonary disease.

Effective therapeutic modalities and drug administration strategies for the treatment of chronic obstructive pulmonary disease (COPD) exacerbations are lacking. Here, mucus and biofilm dual-penetrating immunoantimicrobials (IMAMs) are developed for bridging antibacterial therapy and pro-resolving immunotherapy of COPD. IMAMs are constructed from ceftazidime (CAZ)-encapsulated hollow mesoporous silica nanoparticles (HMSNs) gated with a charge/conformation-transformable polypeptide. The polypeptide adopts a negatively charged, random-coiled conformation, masking the pores of HMSNs to prevent antibiotic leakage and allowing the nebulized IMAMs to efficiently penetrate the bronchial mucus and biofilm. Inside the acidic biofilm, the polypeptide transforms into a cationic and rigid α helix, enhancing biofilm retention and unmasking the pores to release CAZ. Meanwhile, the polypeptide is conditionally activated to disrupt bacterial membranes and scavenge bacterial DNA, functioning as an adjuvant of CAZ to eradicate lung-colonizing bacteria and inhibiting Toll-like receptor 9 activation to foster inflammation resolution. This immunoantibacterial strategy may shift the current paradigm of COPD management.

RSM-CCD optimized hollow mesoporous silica nanospheres encapsulating sorafenib induce mitochondrial membrane potential mediated apoptotic cell death in non-small cell lung cancer

Hollow mesoporous silica nanoparticles (HMSNs) are considered appealing nanovehicles for drug delivery due to their exceptional drug loading and release potential. This study plans to synthesize HMSNs using a novel, quick, and economical procedure in co-relation with traditional mesoporous silica nanoparticles (MSNs) and optimize their synthesis by using the RSM-CCD approach. The influence of independent variables, i.e., CTAB (X1), TEOS (X2), and pH (X3), was evaluated by a 3-factorial design and ANOVA. RSM-CCD depicted the best synthesis formulation. CTAB: 0.3 g, TEOS: 3 ml, pH: 11.5. Optimized MSNs and HMSNs were characterized by DLS, XRD, SEM, FTIR, TEM, BET, XPS, and FE-SEM. Subsequently, hemocompatibility analysis revealed excellent compatibility of the nanosamples toward human RBCs. The drug loading efficiency of SF-MSNs and SF-HMSNs was 13.71 ± 0.33 % and 51.31 ± 0.94 %, respectively. A drug dissolution study revealed that sorafenib (SF) was released sustainably, with a cumulative release percentage of 67 % (HMSNs) and 77 % (MSNs) at 72 h, proving the superiority of SF-HMSNs over sustained release. In-vitro cell culture studies explored the anti-tumorigenic prospects of free and encapsulated SF. Cell cytotoxicity was assessed by MTT assay against A549 cells, indicating enhanced toxicity for optimized SF-HMSNs. The IC50 value substantially decreased from 10.5 to 5.8 μg/ml (a 1.8-fold decrease) after encapsulation. Additionally, In-vitro assays reflected MMP-mediated apoptotic cell death in A549 cells due to increased drug sensitivity and ROS generation. Collectively, these findings suggest that HMSNs are an ideal drug delivery vehicle due to the sustainable release of SF for NSCLC treatment.

Mitochondria-Targeting and Oxygen Self-Supplying Eccentric Hollow Nanoplatform for Enhanced Breast Cancer Photodynamic Therapy

Photodynamic therapy (PDT) has received increasing attention for tumor therapy due to its minimal invasiveness and spatiotemporal selectivity. However, the poor targeting of photosensitizer and hypoxia of the tumor microenvironment limit the PDT efficacy. Herein, eccentric hollow mesoporous organic silica nanoparticles (EHMONs) are prepared by anisotropic encapsulation and hydrothermal etching for constructing PDT nanoplatforms with targeting and hypoxia-alleviating properties. The prepared EHMONs possess a unique eccentric hollow structure, a uniform size (300 nm), a large cavity, and ordered mesoporous channels (2.3 nm). The EHMONs are modified with the mitochondria-targeting molecule triphenylphosphine (CTPP) and photosensitizers chlorin e6 (Ce6). Oxygen-carrying compound perfluorocarbons (PFCs) are further loaded in the internal cavity of EHMONs. Hemolytic assays and in vitro toxicity experiments show that the EHMONs-Ce6-CTPP possesses very good biocompatibility and can target mitochondria of triple-negative breast cancer, thus increasing the accumulation of photosensitizers Ce6 at mitochondria after entering cancer cells. The EHMONs-Ce6-CTPP@PFCs with oxygen-carrying ability can alleviate hypoxia after entering in the cancer cell. Phantom and cellular experiments show that the EHMONs-Ce6-CTPP@PFCs produce more singlet oxygen reactive oxygen species (ROSs). Thus, in vitro and in vivo experiments demonstrated that the EHMONs-Ce6-CTPP@PFCs showed excellent treatment effects for triple-negative breast cancer. This research provides a new method for a targeting and oxygen-carrying nanoplatform for enhancing PDF effectiveness.

A combined nanotherapeutic approach targeting farnesoid X receptor, ferroptosis, and fibrosis for nonalcoholic steatohepatitis treatment

Obeticholic acid (OCA), a farnesoid X receptor (FXR) agonist with favorable effects on fatty and glucose metabolism, has been considered the leading candidate drug for nonalcoholic steatohepatitis (NASH) treatment. However, its limited effectiveness in resolving liver fibrosis and lipotoxicity-induced cell death remains a major drawback. Ferroptosis, a newly recognized form of cell death characterized by uncontrolled lipid peroxidation, is involved in the progression of NASH. Nitric oxide (NO) is a versatile biological molecule that can degrade extracellular matrix. In this study, we developed a PEGylated thiolated hollow mesoporous silica nanoparticles (MSN) loaded with OCA, as well as a ferroptosis inhibitor liproxsatin-1 and a NO donor S-nitrosothiol (ONL@MSN). Biochemical analyses, histology, multiplexed flow cytometry, bulk-tissue RNA sequencing, and fecal 16S ribosomal RNA sequencing were utilized to evaluate the effects of the combined nanoparticle (ONL@MSN) in a mouse NASH model. Compared with the OCA-loaded nanoparticles (O@MSN), ONL@MSN not only protected against hepatic steatosis but also greatly ameliorated fibrosis and ferroptosis. ONL@MSN also displayed enhanced therapeutic actions on the maintenance of intrahepatic macrophages/monocytes homeostasis, inhibition of immune response/lipid peroxidation, and correction of microbiota dysbiosis. These findings present a promising synergistic nanotherapeutic strategy for the treatment of NASH by simultaneously targeting FXR, ferroptosis, and fibrosis.

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.

Modulation of macrophage polarity with carboxymethyl chitin gated hollow mesoporous silica nanoparticles for elevating anti-tumor chemotherapy

The weak immunity of tumors after chemotherapy could cause tumor metastasis and progression. Therefore, to overcome the dilemma of obvious immune deficiency caused by chemotherapy, a nanosystem (N-IL-12/DOX/α-TOS) consisted of thioketal (TK) bonds linked-hollow mesoporous silica nanoparticles (HMSNs) coated with carboxymethyl chitin (CMCH) by electrostatic interaction, and surface-functionalized glucose-regulated protein 78 binding peptide was prepared for loading doxorubicin (DOX), IL-12 and α-tocopheryl succinate (α-TOS). N-IL-12/DOX/α-TOS displayed a mean size of 275 nm after encapsulated DOX, IL-12 and α-TOS with loading contents of 2.04 × 10−4, 4.01 × 10−2 and 7.12 × 10−2, respectively. The drug-free nanoparticles (NPs) showed good biocompatibility to both 4 T1 cells and RAW264.7 macrophages. N-IL-12/DOX/α-TOS could achieve localized release of IL-12, DOX and α-TOS by pH and H2O2 trigger in the tumor microenvironment (TME). Moreover, the combined therapy by N-IL-12/DOX/α-TOS remarkably elevated the anti-tumor therapeutic efficacy, enhanced immune responses via promoting tumor-associated macrophage (TAM) polarization into tumoricidal M1 phenotypes, and decreased lung metastasis with reduced side effects. N-IL-12/DOX/α-TOS exhibited as a promising strategy for combining chemotherapy and local macrophage modulation-immunotherapy for anti-tumor therapy.

Determination of free fatty acids in edible oil based on hollow mesoporous silica nanoparticles

In our study, ammoniated hollow mesoporous silica nanoparticles (NH2-HMSN) with uniform diameter and stable structure were successively prepared via SiO2 core hard template method. Fourier transformed infrared spectroscopy revealed that amino group was effectively modified. Adsorption experiments showed that adsorption capacity of NH2-HMSN towards free fatty acids (FFAs) was superior to aminated mesopores or silica microspheres. Following through optimization of extraction conditions, FFAs from edible oil samples were successfully gathered by NH2-HMSN and showed favorable linearities (0.2–90 μg g−1), remarkably low limit of detections (0.03–0.15 nmol g−1), acceptable recoveries (85.08–96.82 %) and relatively accurate precisions (1.64–4.99 %). In comparison to existing adsorbent, NH2-HMSN could be successfully prepared via the chemical reaction of common raw materials under normal pressure and temperature. Furthermore, NH2-HMSN with hollow and mesoporous structure was more effective than the current adsorbents aimed at FFAs analysis in aspect of surface area and adsorption capacity.

Thermal-responsive gated nanocomposite of antibacterial gold nanoclusters

A thermal-responsive antibacterial nanocomposite was developed based on the photodynamic gold nanoclusters (AuNCs). N-cetyltrimethylammonium bromide was applied as a soft template to prepare silica nanoparticles (sSiO2@CTAB-SiO2). After etching, the hollow mesoporous silica nanoparticles (HMSN) were prepared and subsequently surface-grafted with thermal-responsive poly(N-isopropylacrylamide) to construct nanocomposites, named HMSN-PNIPAM. The ultrasmall-sized AuNCs matched well with the pore size of HSMN. The poly(N-isopropylacrylamide) underwent a reversible phase transition at varied temperature, which accompanied the change of apparent volume. It could realize the open/closed switch of HMSN pores for AuNCs loading in and sealed up effectively, thus constructing the AuNCs-loaded nanocomposites, termed as HMSN-AuNC. Under mild heating and light irradiation, the AuNCs in HMSN-AuNC could be released and generate reactive oxygen species, which could then perform the bacteria killing. Therefore, taking advantages of the thermo-responsiveness of poly(N-isopropylacrylamide) and the photodynamic property of AuNCs, the nanocomposite exhibited a "switching" effect on both temperature and light, and its antibacterial performance could be realized in a controlled manner.