Mesoporous Carbon Nanoparticles Research Articles

Mesoporous carbon biomaterials

Nano-biotechnology provides highly efficient and versatile strategies to improve the diagnostic precision and therapeutic efficiency of serious diseases. The development of new biomaterial systems provides great opportunities for the successful clinical translation of nano-biotechnology for personalized biomedicine to benefit patients. As a new inorganic material system, mesoporous carbon biomaterials (MCBs) combine the merits of a mesoporous nanostructure and carbonaceous composition, showing superior qualities compared with traditional mesoporous silica and other carbon-based nanosystems, such as graphene, carbon nanotubes, and fullerene. Thus, this review focuses on the rational design, chemical synthesis, and biomedical applications of MCBs. The synthetic strategies for MCBs, especially mesoporous carbon nanoparticles (MCNs), are summarized, and several representative biomedical applications of MCBs are discussed in detail. MCBs perform well for on-demand drug-release, photothermal therapy, synergistic therapy, fluorescent labeling of cancer cells, bio-adsorption of in vivo toxic pathogenic substances, peptide separation, and biosensing. The preliminary biosafety issue of MCBs is also briefly discussed. Finally, the critical issues and challenges facing the future development of MCBs for clinical translation are considered. There is great promise for MCBs to reach clinical translations for biomedical applications based on their unique nanostructure, composition, and biocompatibility once some critical issues are fully addressed.

Electrically Contacted Bienzyme‐Functionalized Mesoporous Carbon Nanoparticle Electrodes: Applications for the Development of Dual Amperometric Biosensors and Multifuel‐Driven Biofuel Cells

The capping of electron relay units in mesoporous carbon nanoparticles (MPC NPs) by crosslinking of different enzymes on MPC NPs matrices leads to integrated electrically contacted bienzyme electrodes acting as dual biosensors or as functional bienzyme anodes and cathodes for biofuel cells. The capping of ferrocene methanol and methylene blue in MPC NPs by the crosslinking of glucose oxidase (GOx) and horseradish peroxidase (HRP) yields a functional sensing electrode for both glucose and H2O2, which also acts as a bienzyme cascaded system for the indirect detection of glucose. A MPC NP matrix, loaded with ferrocene methanol and capped by GOx/lactate oxidase (LOx), is implemented for the oxidation and detection of both glucose and lactate. Similarly, MPC NPs, loaded with 2,2′‐azino‐bis(3‐ethylbenzo­thiazoline‐6‐sulphonic acid), are capped with bilirubin oxidase (BOD) and catalase (Cat), to yield a bienzyme O2 reduction cathode. A biofuel cell that uses the bienzyme GOx/LOx anode and the BOD/Cat cathode, glucose and/or lactate as fuels, and O2 and/or H2O2 as oxidizers is assembled, revealing a power efficiency of ≈90 μW cm−2 in the presence of the two fuels. The study demonstrates that multienzyme MPC NP electrodes may improve the performance of biofuel cells by oxidizing mixtures of fuels in biomass.

Therapeutic use of Fisetin and Fisetin Loaded on Mesoporous Carbon Nanoparticle (MCN) in Thioglycollate-induced Peritonitis

Background: The pathophysiology of aseptic peritonitis involves inflammation of the serosal membrane that lines the abdominal cavity and the organs contained therein. The etiology of peritonitis is complicated and is involved in various processes, of which, the most important one is the inflammatory reaction. During the pathological process of peritonitis, NF-κB plays an activating role in the inflammatory reaction, which might be a potential therapeutic target in the therapy of certain inflammatory diseases. We studied the anti-inflammatory and pro-regenerative actions of Fisetin, a flavonol found in many plants, in a mouse model of thioglycollate-induced peritonitis, as well as the actions of fisetin administered with a nanoparticle such as mesoporous carbon nanoparticle (MCN). BALB/c mice were used in this study. Results: We found cell recruitment in the blood increased with the administration of thioglycollate (TG) after 24 h, 48 h, 72 h and 96 h, showing that it has induced inflammation. Cell recruitment was successfully inhibited by fisetin, and with MCN+fisetin. In the peritoneal fluid, total cell recruitment was increased, which was successfully inhibited with fisetin and MCN+fisetin treatment. TG treatment significantly reduced cell proliferation in the blood, PF and BM, within 24 h, till 96 h. Interestingly, cell proliferation increased with fisetin treatment, and with MCN+fisetin. The clonogenic potential of the tissues decreased significantly within 24 h, with administration of TG. Both fisetin treatment and MCN+fisetin treatment restored the clonogenic potential of the tissues. There was a decrease in Th2 cytokines with TG treatment, in blood after 48 h, and both fisetin and MCN+fisetin increased the cytokine content. Conclusion: In conclusion, we found that fisetin had a promising therapeutic effect on the peritonitis.

Synthesis of mesoporous carbon nanoparticles with large and tunable pore sizes.

Mesoporous carbon nanoparticles (MCNs) with large and adjustable pores have been synthesized by using poly(ethylene oxide)-b-polystyrene (PEO-b-PS) as a template and resorcinol-formaldehyde (RF) as a carbon precursor. The resulting MCNs possess small diameters (100-126 nm) and high BET surface areas (up to 646 m(2) g(-1)). By using home-designed block copolymers, the pore size of MCNs can be tuned in the range of 13-32 nm. Importantly, the pore size of 32 nm is the largest among the MCNs prepared by the soft-templating route. The formation mechanism and structure evolution of MCNs were studied by TEM and DLS measurements, based on which a soft-templating/sphere packing mechanism was proposed. Because of the large pores and small particle sizes, the resulting MCNs were excellent nano-carriers to deliver biomolecules into cancer cells. MCNs were further demonstrated with negligible toxicity. It is anticipated that this carbon material with large pores and small particle sizes may have excellent potential in drug/gene delivery.

Mesoporous carbon nanoparticles: a super catalyst support for fuel cells

Ionic liquid-modified mesoporous carbon nanoparticles exhibit good electrochemical activity compared with commercial Pt/C catalyst and Pt nanoparticles.

Eco-friendly synthesis of hierarchical ginkgo-derived carbon nanoparticles/NiAl-layered double hydroxide hybrid electrodes toward high-performance supercapacitors

Eco-friendly prepared three-dimensional mesoporous carbon nanoparticles (CP)/NiAl-layered double hydroxide (NiAl-LDH) hybrids (CP/LDHs) with hierarchical nanostructures exhibited remarkably improved electrochemical performance in supercapacitors.

Mesoporous Nano-carbon particle Loaded Fisetin has a Positive Therapeutic Effect in a Murine Preclinical Model of Ovalbumin Induced Acute Allergic Asthma

Inflammation is a complex process initiated by several factors ranging from bacterial infection and chemical injury to environmental pollution that causes cell injury or death, release of inflammatory mediators which further trigger the up-regulation of other pro-inflammatory cytokines and chemokines as well as sequestration of specific immunoglobulin molecules. Th2 inflammation is an allergenic reaction by primed T and B cells and during manifestation of acute asthma, this immune reaction takes the form of super-activated macrophages, eosinophils, neutrophils and an array of Th2 skewed inflammasome development. An anti-inflammatory molecule should be able to potently reduce or inhibit one or more of the aforementioned traits. Several organic and inorganic substances have been studied to evaluate their potential as anti-inflammatory molecules, among which nanotechnology has emerged as a promising aid to anti-inflammatory activities. Nanoparticle-incorporated mesoporous carbon particles have a wide range of applications in controlled drug delivery. These nano particles are capable of delivering drugs inside the cell, even in a sub-cellular organelle specific manner. In this study, inflammation is initiated by using different classes of pro-inflammatory stimuli, such as OVA (chicken ovalbumin), LPS (lipopolysaccharide) and TG (thioglycollate), and by applying such nano-concoctions, the anti-inflammatory activities of certain compounds are assessed in in vivo models. The anti- inflammatory action of a novel drug made from extract of strawberry (fisetin) has been evaluated in an in vivo model of acute allergic asthma in Balb/c mice. Also, attempts are being made to narrow the delivery window within the cell, by loading the drug onto the constructed mesoporous carbon nanoparticle. It has been found to maintain cell viability significantly by reducing oxidative and nitrosative stress and ameliorating the overall development of composite asthma phenotype in this murine preclinical model.

A Free‐Standing and Ultralong‐Life Lithium‐Selenium Battery Cathode Enabled by 3D Mesoporous Carbon/Graphene Hierarchical Architecture

High capacity cathode materials for long‐life rechargeable lithium batteries are urgently needed. Selenium cathode has recently attracted great research attention due to its comparable volumetric capacity to but much better electrical conductivity than widely studied sulfur cathode. However, selenium cathode faces similar issues as sulfur (i.e., shuttling of polyselenides, volumetric expansion) and high performance lithium‐selenium batteries (Li–Se) have not yet been demonstrated at selenium loading >60% in the electrode. In this work, a 3D mesoporous carbon nanoparticles and graphene hierarchical architecture to storage selenium as binder‐free cathode material (Se/MCN‐RGO) for high energy and long life Li–Se batteries is presented. Such architecture not only provides the electrode with excellent electrical and ionic conductivity, but also efficiently suppresses polyselenides shuttling and accommodates volume change during charge/discharge. At selenium content of 62% in the entire cathode, the free‐standing Se/MCN‐RGO exhibits high discharge capacity of 655 mAh g−1 at 0.1 C (97% of theoretical capacity) and long cycling stability with a very small capacity decay of 0.008% per cycle over 1300 cycles at 1 C. The present report demonstrates significant progress in the development of high capacity cathode materials for long‐life Li batteries and flexible energy storage device.

Catalytic Hydrolysis of Cellulose to Glucose Using Weak-Acid Surface Sites on Postsynthetically Modified Carbon

We demonstrate depolymerization of adsorbed (1 → 4)- β-d-glucans (β-glu) derived from crystalline cellulose (Avicel), using weak-acid sites of postsynthetically surface-functionalized mesoporous carbon nanoparticle (MCN) catalysts HT5-HSO3-MCN and COOH-MCN and investigate the role of acid-site density and β-glu molecular weight on this depolymerization. Both HT5-HSO3-MCN and COOH-MCN hydrolyze adsorbed β-glu strands and afford glucose yields of 73% and 90%, respectively, at a buffered pH of 2.0 after 3 h treatment at 180 °C. These yields are significantly higher than the 16% yield of an unfunctionalized MCN-control catalyst under otherwise identical conditions, demonstrating the importance of postsynthetic surface functionalization for achieving weak-acid catalytic hydrolysis. Highlighting the important role of confinement in this catalysis, all yields are generally depressed when using a lower rather than higher molecular weight of adsorbed β-glu strands on the same catalyst. The catalytic hydrolysis rate also generally increases upon decreasing buffer pH—particularly so for the more acidic carboxylic acid-functionalized catalyst COOH-MCN. This is interpreted on the basis of a higher local density of surface weak-acid sites upon protonation of surface conjugate-base functionality, as demonstrated by a comparison of zeta potential measurements of catalysts COOH-MCN and MCN.

Near-infrared absorbing mesoporous carbon nanoparticle as an intelligent drug carrier for dual-triggered synergistic cancer therapy

Herein a novel multifunctional nanoplatform based on surface engineered mesoporous carbon nanoparticle (MCN) is developed for effective dual-triggered synergistic cancer therapy. MCNs employed in the study not only function as near-infrared absorbing agents but also as nanocarriers with a high drug loading efficiency. The surface modification of MCN with biomacromolecules (hyaluronic acid) through disulfide unit makes the system be sensitive to both intracellular hyaluronidase-1 and GSH to release the carried drug. The hyaluronic acid on MCN simultaneously confers the system biocompatibility and a cancer cell targeting ability. By combining these capabilities, the multifunctional nanoplatform shows an effective therapeutic efficiency toward the target cells.

Versatile hybrid polyethyleneimine–mesoporous carbon nanoparticles for targeted delivery

To meet the needs of targeted drug delivery and medical imaging, uniform mesoporous carbon spheres (UMCS) were functionalized using hyperbranched polyethyleneimine (PEI) covalently linked with fluorescein isothiocyanate (FITC) and folic acid (FA). Folate-receptor-positive KB cancer cells internalized five times more nanoparticles than A549 cells deficient in folate receptors in vitro using flow cytometry and confocal microscopy. The in vivo distribution results also confirmed that the FA–PEI–FITC–UMCS nanoparticles could target the FA-positive tumors. In addition, the specifically targeted hybrid carbon nanoparticles exhibited non-cytotoxic and controlled intracellular release (pH dependent) of the loaded agents. The in vivo antitumor effect of the paclitaxel (PTX)-loaded nanoparticles was investigated in Kunming mice harboring a hepatic H22 tumor. PTX-loaded FA–PEI–UMCS nanoparticles displayed superior antitumor effects compared to other PTX formulations, and the tumor growth inhibition rate was 86.53% compared with the control group (saline) for the enhanced targeted accumulation of NPs in tumor cells.

A novel nonenzymatic hydrogen peroxide sensor based on the synthesized mesoporous carbon and silver nanoparticles nanohybrid

Here, we report the synthesis and characterization of a novel nanohybrid composed of mesoporous carbon and silver nanoparticles (MC/AgNPs) to use in amperometric sensing of hydrogen peroxide (H2O2). In this process, the MC was synthesized by using the mesoporous silica as a template and glucose as a carbon source. The AgNPs were produced by in situ chemical reduction of silver nitrate through glucose as a reducing and stabilizing agent in the presence of MC to give the desired MC/AgNPs nanohybrid. It was investigated by field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and electrochemical measurements. The obtained nanohybrid was used to modify a glassy carbon electrode and to fabricate an amperometric sensor for H2O2 determination at a working potential of −200mV vs. silver/silver chloride electrode in aqueous 0.1M phosphate buffer solution (pH 7.0). The resulted sensor can detect H2O2 in the concentration range of 0.1–41μM with a detection of limit 50nM at a signal-to-noise ratio of 3.

Molecularly imprinted polymer/mesoporous carbon nanoparticles as electrode sensing material for selective detection of ofloxacin

Molecularly imprinted polymer/mesoporous carbon composite nanoparticles (MCNs@MIP) were prepared through covalent grafting of the polymer onto the surface of mesoporous carbon nanoparticles by precipitation polymerization using ofloxacin as a template. The MCNs@MIP were well monodisperse, with a diameter of ~220nm. Using the MCNs@MIP as electrode sensing material, the electrode showed good electrochemical activity and selective response to ofloxacin in aqueous solutions. There was a linear relationship between the peak currents in cyclic voltammetry measurement and ofloxacin concentrations in the range of 0.5–100μM, with a limit of detection (S/N=3) of 80nM.

Hydrogenation of carbon monoxide to higher alcohols over ordered mesoporous carbon nanoparticle-supported Rh-based catalysts

Two-dimensional hexagonally ordered mesoporous carbon nanoparticles (MCNs) were synthesized using the templating synthesis method. MCNs were introduced as supports for the catalytic thermochemical conversion of syngas to higher alcohols. The catalytic test of the promoted Rh/MCNs was performed using a fixed bed reactor. The catalytic results reveal that the nano-sized MCN-supported catalysts exhibited higher C2+ alcohol production with a high ethanol selectivity compared with the micro-sized ordered mesoporous carbon-supported catalysts. The promoted Rh/CMK-5-MCN with a hollow framework configuration exhibited a superior space–time yield of the total C2+ alcohols compared with the promoted Rh/CMK-3-MCN with a rod carbon framework. It indicates that the promoted Rh/MCNs exhibited different catalytic activities and selectivities of higher alcohols, which is attributed to the Rh particle size and the reactant accessibility to active sites through the morphological effects of the MCNs.

Facile synthesis of hydrophilic multi-colour and upconversion photoluminescent mesoporous carbon nanoparticles for bioapplications.

Hydrophilic mesoporous carbon nanoparticles (MCNs) have been synthesized via an extremely facile precursor carbonization-in-hot solvent route. The synthesized MCNs show well-defined particle and pore size distribution at around 100 nm and 2.7 nm, respectively, and multicolor and upconversion photoluminescence, which endow the MCNs with multicolor/upconversion bioimaging and drug delivery properties.

Functionalized mesoporous carbon nanoparticles for targeted chemo-photothermal therapy of cancer cells under near-infrared irradiation

Chemo-photothermal therapy with the combination of chemotherapy and photothermal therapy using mesoporous carbon nanoparticles has emerged as a promising anticancer treatment for its synergistic effects.

Hydrolysis Catalysis of Miscanthus Xylan to Xylose Using Weak-Acid Surface Sites

Adsorption and hydrolysis of xylan polysaccharides extracted from Miscanthus biomass are demonstrated, using surface-functionalized MCN (mesoporous carbon nanoparticle) materials that comprise weak-acid sites, at a pH corresponding to biomass extract. Extracted xylan polysaccharides consist of a peak molecular weight of 2008 g/mol according to GPC (gel-permeation chromatography), corresponding to approximately 15 xylose repeat units, and, a calculated length of 7 nm and radius of gyration of 2.0 nm based on molecular dynamics simulations. A highly active material for the adsorption and depolymerization of xylan is a hydrothermally treated sulfonated MCN material, which consists of 90% weak-acid sites. In spite of the large polysaccharide size relative to its 1.6 nm pore radius, this material adsorbs up to 76% of xylan strands from extract solution, at a weight loading of 29% relative to MCN. Starting with a 9.7% xylose yield in Miscanthus extract, this material hydrolyzes extracted xylan to xylose, and achieves a 74.1% xylose yield, compared with 24.1% yield for the background reaction in acetate buffer, at 150 °C for 4 h. Catalytic comparisons with other MCN-based materials highlight the role of confinement and weak-acid surface sites, and provide some correlation between activity and phenolic OH acid-site density. However, the lack of a directly proportional correlation between weak-acid site density and catalyzed hydrolysis rate signifies that only a fraction of weak-acid surface sites are catalytically active, and this is likely to be the sites that are present in a high local concentration on the surface, which would be consistent with previously observed trends in the hydrolysis catalysis of chemisorbed glucans on inorganic-oxide surfaces.

Enzyme-Capped Relay-Functionalized Mesoporous Carbon Nanoparticles: Effective Bioelectrocatalytic Matrices for Sensing and Biofuel Cell Applications

The porous high surface area and conducting properties of mesoporous carbon nanoparticles, CNPs (<500 nm diameter of NPs, pore dimensions ∼6.3 nm), are implemented to design electrically contacted enzyme electrodes for biosensing and biofuel cell applications. The relay units ferrocene methanol, Fc-MeOH, methylene blue, MB(+), and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid), ABTS(2-), are loaded in the pores of the mesoporous CNPs, and the pores are capped with glucose oxidase, GOx, horseradish peroxidase, HRP, or bilirubin oxidase, BOD, respectively. The resulting relay/enzyme-functionalized CNPs are immobilized on glassy carbon electrodes, and the relays encapsulated in the pores are sufficiently free to electrically contact the different enzymes with the bulk electrode supports. The Fc-MeOH/GOx CNP-functionalized electrode is implemented for the bioelectrocatalyzed sensing of glucose, and the MB(+)/HRP-modified CNPs are applied for the electrochemical sensing of H2O2. The ABTS(2-)/BOD-modified CNPs provide an effective electrically contacted material for the bioelectrocatalyzed reduction of O2 (kcat = 94 electrons·s(-1)). Integration of the Fc-MeOH/GOx CNP electrode and of the electrically wired ABTS(2-)/BOD CNP electrode as anode and cathode, respectively, yields a biofuel cell revealing a power output of ∼95 μW·cm(-2).

Construction of Homogenous/Heterogeneous Hollow Mesoporous Silica Nanostructures by Silica-Etching Chemistry: Principles, Synthesis, and Applications

Colloidal hollow mesoporous silica nanoparticles (HMSNs) are aspecial type of silica-based nanomaterials with penetrating mesopore channels on their shells. HMSNs exhibit unique structural characteristics useful for diverse applications: Firstly, the hollow interiors can function as reservoirs for enhanced loading of guest molecules, or as nanoreactors for the growth of nanocrystals or for catalysis in confined spaces. Secondly, the mesoporous silica shell enables the free diffusion of guest molecules through the intact shell. Thirdly, the outer silica surface is ready for chemical modifications, typically via its abundant Si-OH bonds. As early as 2003, researchers developed a soft-templating methodto prepare hollow aluminosilicate spheres with penetrating mesopores in a cubic symmetry pattern on the shells. However, adapting this method for applications on the nanoscale, especially for biomedicine, has proved difficult because the soft templating micelles are very sensitive to liquid environments, making it difficult to tune key parameters such as dispersity, morphology and structure. In this Account, we present the most recent developments in the tailored construction of highly dispersive and monosized HMSNs using simple silica-etching chemistry, and we discuss these particles' excellent performance in diverse applications. We first introduce general principles of silica-etching chemistry for controlling the chemical composition and the structural parameters (particle size, pore size, etching modalities, yolk-shell nanostructures, etc.) of HMSNs. Secondly, we include recent progress in constructing heterogeneous, multifunctional, hollow mesoporous silica nanorattles via several methods for diverse applications. These elaborately designed HMSNs could be topologically transformed to prepare hollow mesoporous carbon nanoparticles or functionalized to produce HMSN-based composite nanomaterials. Especially in biomedicine, HMSNs are excellent as carriers to deliver either hydrophilic or hydrophobic anti-cancer drugs, to tumor cells, offering enhanced chemotherapeutic efficacy and diminished toxic side effects. Most recently, research has shown that loading one or more anticancer drugs into HMSNs can inhibit metastasis or reverse multidrug resistance of cancer cells. HMSNs could also deliver hydrophobic perfluorohexane (PFH) molecules to improve high intensity focused ultrasound (HIFU) cancer surgery by changing the tissue acoustic environment; and HMSNs could act as nanoreactors for enhanced catalytic activity and/or durability. The versatility of silica-etching chemistry, a simple but scalable synthetic methodology, offers great potential for the creation of new types of HMSN-based nanostructures in a range of applications.

Preparation of molecularly imprinted polymer nanoparticles for selective removal of fluoroquinolone antibiotics in aqueous solution

In this study, novel molecularly imprinted polymer nanoparticles (nanoMCN@MIPs) were prepared by covalent grafting of ofloxacin-imprinted polymer onto the surface of mesoporous carbon nanoparticles (MCNs). SEM analyses indicated that the prepared nanoMCN@MIPs were almost uniform, and their geometrical mean diameter was about 230nm. The sorption behaviors of the nanoMCN@MIPs including sorption kinetics and isotherms, effect of pH, ionic strength, and cross-reactivity were investigated in detail. The adsorption capacity of the nanoparticles for ofloxacin was 40.98mg/g, with a selectivity factor of 2.6 compared to the nonimprinted polymer nanoparticles (nanoMCN@NIPs). The feasibility of removing fluoroquinolone antibiotics (FQs) from environmental waters with the nanoMCN@MIPs was demonstrated using sea water spiked with six typical FQs (ofloxacin, gatifloxacin, balofloxcacin, enrofloxacin, norfloxacin and sarafloxacin). The nanoMCN@MIPs could be reused at least five times with removal efficiency more than 90% except for norfloxacin.