Mesoporous Carbon Nanoparticles Research Articles

Size-dependent activity of Fe-N-doped mesoporous carbon nanoparticles towards oxygen reduction reaction

The rational design of Fe–N–C catalysts that possess easily accessible active sites and favorable mass transfer, which are usually determined by the structure of catalyst supports, is crucial for the oxygen reduction reaction (ORR). In this study, an oleic acid-assisted soft-templating approach is developed to synthesize size-controlled nitrogen-doped carbon nanoparticles (ranging from 130 nm to 60 nm and 35 nm, respectively) that feature spiral mesopores on their surface (SMCs). Next, atomically dispersed Fe–Nx sites are fabricated on the size-tunable SMCs (Fe1/SMC-x, where x represents the SMC size) and the size-dependent activity toward ORR is investigated. It is found that the catalytic performance of Fe1/SMCs is significantly influenced by the size of SMCs, where the Fe1/SMC-60 catalyst shows the highest ORR activity with a half-wave potential of 0.90 V vs. RHE in KOH electrolyte, indicating that the gas-liquid-solid three-phase interface on the Fe1/SMC-60 enhances the accessibility of Fe–Nx sites. In addition, when using Fe1/SMC-60 as the cathode catalyst in aqueous zinc-air batteries (ZABs), it delivers a higher open-circuit voltage (1.514 V), a greater power density (223 mW cm−2), and a larger specific capacity/energy than Pt/C-based counterparts. These results further highlight the potential of Fe1/SMC-60 for practical energy devices associated with ORR and the importance of size-controlled synthesis of SMCs.

Mesoporous carbon nanoparticles embedded with iron in hydrogen-photothermal synergistic therapy

We developed a new method to synthesize polyethylene glycol modified ultra small iron embedded in mesoporous carbon nanoparticle (C/Fe-PEG NP) for hydrogen (H2) assisted photothermal synergistic therapy. Herein, we use a simple in-situ reduction method to obtain the C/Fe NP in one-step carbonizing process, which is further modified by the biocompatible polyethylene glycol (PEG) on the surface of C/Fe NP to acquire high stability in physiological solutions. Utilizing the excellent photothermal property from the mesoporous carbon and the controllable H2 release property in the weakly acidic tumor microenvironment by the ultra-small Fe, the obtained C/Fe-PEG NPs can effective kill the cancer cells, meanwhile, protect normal cells without drugs. This selective anti-cancer mechanism of C/Fe-PEG NPs may because the produced H2 selective change the mitochondrial energy metabolism. In vivo results prove that the C/Fe-PEG NPs achieve excellent tumor ablation therapeutic effect and normal tissue protecting ability benefit from the H2-assisted photothermal therapy, promising the use of novel nanomaterials with more safety method for future cancer therapy.

MRI Directed Magnevist Effective to Study Toxicity of Gd-Doped Mesoporous Carbon Nanoparticles in Mice Model.

Magnetic resonance imaging (MRI) has been a valuable and widely used examination technique in clinical diagnosis and prognostic efficacy evaluation. The introduction of MRI contrast agent (CA) improves its sensitivity obviously, particularly with the development of nano-CA, which presents higher contrast enhancement ability. However, systematical evaluation of their toxicity is still limited, hampering their further translation in clinics. In this paper, to systematically evaluate the toxicity of nano-CA, Gd-doped mesoporous carbon nanoparticles (Gd-MCNs) prepared by a one-step hard template method were introduced as a model and clinically used MRI CA, Magnevist (Gd-DTPA) as control. Their in vitro blood compatibility, cellular toxicity, DNA damage, oxidative stress, inflammation response as well as in vivo toxicity and MR imaging behaviors were studied and compared. The experimental results showed that compared with Gd-DTPA, Gd-MCNs displayed negligible influence on the red blood cell shape, aggregation, BSA structure, macrophage morphology and mitochondrial function. Meanwhile, limited ROS and inflammatory cytokine production also illustrated the cellular compatibility of Gd-MCNs. For in vivo toxicity evaluation, Gd-MCNs presented acceptable in vivo biosafety even under 12 times injection for 12 weeks. More importantly, at the same concentration of Gd, Gd-MCNs displayed better contrast enhancement of tumor than Gd-DTPA, mainly coming from its high MRI relaxation rate which is nearly 9 times that of Gd-DTPA. In this paper, we focus on the toxicity evaluation of MRI nano-CA, Gd-MCNs from different angles. With Gd-DTPA as control, Gd-MCNs appeared to be highly biocompatible and safe nanoparticles that possessed promising potentials for the use of MRI nano-CA. In the future, more research on the long-term genotoxicity and the fate of nanoparticles after being swallowed should be performed.

Bioderived Mesoporous Carbon@Tungsten Oxide Nanocomposite as a Drug Carrier Vehicle of Doxorubicin for Potent Cancer Therapy.

Scientists have investigated the possibility of employing nanomaterials as drug carriers. These nanomaterials can preserve their content and transport it to the target region in the body. In this investigation, we proposed a simple method for developing distinctive, bioderived nanostructures with mesoporous carbon nanoparticles impregnated with tungsten oxide (WO3). Prior to characterizing and encapsulating WO3 with bioderived mesoporous carbon, the anticancer drug doxorubicin (DOX) was added to the nanoparticles and examined loading and release study. The approaches for both nanoparticle production and characterization are discussed in detail. Colloidal qualities of the nanomaterial can be effectively preserved while also allowing transdermal transportation of nanoparticles into the body by forming them into green, reusable, and porous nanostructures. Although the theories of nanoparticles and bioderived carbon each have been studied separately, the combination presents a new route to applications connected to nanomedicine. Furthermore, this sample was used to study exotic biomedical applications, such as antioxidant, antimicrobial, and anticancer activities. The W-3 sample had lower antioxidant activity (44.01%) than the C@W sample (56.34%), which was the most potent. A high DOX entrapment effectiveness of 97% was eventually achieved by the C@W sample, compared to a pure WO3 entrapment efficiency of 91%. It was observed that the Carbon/WO3 composite (C@W) sample showed more efficacy because the mesoporous carbon composition with WO3 increases the average surface area and surface-active locations.

Thermal-/pH-triggered hollow mesoporous carbon nanocarrier for NIR-responsive drug release

Intelligent drug-delivery systems are considered one of the most important techniques for improving cancer treatment using existing over-the-counter medicines. However, metallic materials are always accompanied by metabolism problems, whereas chemotherapy produces several side effects in humans. Carbon-based materials exhibit exceptional features such as bio-affinity and bio-degradability. Herein, hollow mesoporous carbon nanoparticles (HMCs) are reported as effective nanocarriers of anti-cancer small drug molecules. Near IR (NIR) sources, which can penetrate most organs, induce thermal effects via non-invasive pathways. NIR radiation not only provides thermal therapy but also is compatible with temperature-sensitive coated responsive polymer shells. The template method was used to synthesize HMCs with size 200 ± 50 nm, under various conditions, to obtain suitably sized and hollow structures for liver-cancer treatment. Additional pH/thermal-bi-responsive poly(N-isopropylacrylamide) (PNIPAM) shells were further coated onto the HMCs to produce multiple shells that could trigger swelling motions in PNIPAM@HMCs, as confirmed via small-angle X-ray scattering (SAXS). NIR results demonstrated an extreme increase to the ∆T of 8.7 and 14.2 °C for HMC and PNIPAM@HMCs, respectively. The SAXS spectra analyzed using SasView simulations demonstrated the multi-shell structures of synthesized HMCs and the release mechanism of PNIPAM@HMCs. Based on the model simulation of SAXS, the different rates of polymer swelling indicated the core shrinkage (229.7 to 134.2 Å) and shell expansion (324.3 to 514.3 Å) at 37 °C and 42 °C, respectively. In addition, the first-order, Higuchi, Korsmeyer–Peppas, and Weibull mathematical models were used to verify the drug-release kinetics, and the model with the highest R2 value was considered most suitable for further application. This paper presents the first SAXS study on PNIPAM@HMCs release kinetics and related mechanisms. This phenomenon indicates NIR-induced PNIPAM@HMCs as an effective strategy for cancer treatment via doxorubicin release.

Release kinetics study of fatty acids eutectic mixture gated mesoporous carbon nanoparticles for chemo-photothermal therapy

Precise drug release in tumor sites is the key to improving the curative effect and reducing the toxic and side effects of chemotherapy. Herein, mesoporous carbon nanoparticles (MCN) and thermo-sensitive biocompatible phase change material (PCM) composed of stearic acid and lauric acid eutectic mixture were integrated for achieving the “on-demand” release of poorly soluble drug mercaptopurine (MP). MCN endowed the system with the potential of photothermal therapy (PTT) as well as high drug-loading efficiency. Fatty acids eutectic mixture with a well-designated melting point of 40 °C was used as the gatekeeper to trap MP in the mesopores of MCN. As expected, the drug was not released until PCM was melted down by the heat generated under NIR irradiation, thus inhibiting the premature release of drugs at body temperature. Notably, the release kinetic study results of inactivated MCN@MP/PCM system demonstrated the premature release of the drug was caused by diffusion, and adjusting the added PCM amounts just changed the controlled release effect of drugs without affecting release mechanisms. According to the cellular uptake, cytotoxicity and anti-tumor spheroids assays, the prominent NIR-triggered drug release property and photothermal effect of MCN@MP/PCM enhanced the antitumor activity, possessing the satisfied synergistic chemo-photothermal antitumor effect with a combination index of 0.554. This work provides a comprehending basis for designing a better-controlled release system to realize a safer and more efficient synergistic antitumor effect.

Dual/Triple Template-Induced Evolved Emulsion for Controllable Construction of Anisotropic Carbon Nanoparticles from Concave to Convex.

Anisotropic mesoporous carbon (AMC) nanoparticles with asymmetric external morphologies, topological internal structure, and superior performance of carbon species are attracting great attention because of their seductive features differentiating them from symmetric nanoparticles. However, a bewildering challenge but crucial desire remains to endow them with flexibly tunable morphology and pore structure. Herein, a dual/triple-templating evolved emulsion strategy for tunable fabrication of AMC nanoparticles with distinctive defined structure by interface-energy-induced self-assembly is first reported based on a brand-new mechanism. It describes the possible formation process of the concave-cavity structure and allows for manipulation of the longitudinal and lateral sizes systematically by adjusting emulsion polarity and sodium oleate dosage, respectively. Interestingly, the internal pore structure can be rearranged into radial channels and the external morphology can realize structural transformation from concave to convex by innovatively introducing the third template n-hexanol, which is unprecedented at nanoscale. Remarkably, due to the excellent properties of carbon species and unique structural characteristics, AMC nanoparticles not only demonstrate good biocompatibility but also exhibit splendid performance in improving the dissolution and release rates of insoluble drug and enhancing the enzyme catalytic efficiency. Generally, this approach provides new inspiration and insights for expanding exquisite anisotropic nanomaterials for many potential applications.

Immunological gadolinium-doped mesoporous carbon nanoparticles for tumor-targeted MRI and photothermal-immune co-therapy.

Photothermal therapy (PTT) is an effective and well-documented approach to thermally ablate tumors. However, the side effect of distal metastasis and recurrence limit its further expansion. At the same time as PTT was developed, the employment of imaging to monitor the treatment of tumors also became meaningful. Herein, as a proof of concept, gadolinium-doped mesoporous carbon nanoparticles (Gd-MCNs) were prepared as nanocarriers, MRI contrast agents, and PTT agents by a one-step hard template method, which realized Gd doping and carbon filling simultaneously, while retaining enough pore space for drug loading. After loading the immune adjuvant, R837, and the coating of tumor extracellular vesicle, the obtained biomimetic nanoparticles (EV@Gd-MCNs-R837) not only allowed tumor MRI, but also inhibited the primary tumor and its metastasis with long-term immune memory in vivo. This study provides proof for the potential of Gd-MCNs-based biomimetic nanoparticles for targeted PTT/immune-enhanced synergistic theranostic of tumors.

Formation and electrochemical properties of ternary mesoporous carbon, coordination C60Pd polymer and palladium nanoparticle composites

This work describes the preparation and properties of composites based on spherical mesoporous carbon nanoparticles and fullerene-coordinated C60Pd polymer. The composite material was synthesized under a multistep chemical procedure. In the first step, mesoporous carbon nanoparticles were synthesized via a template-assisted method. Next, the C60 fullerene was incorporated into mesoporous carbon pores, and then the polymerization process was carried out in a solution containing a Pd(0) complex. The composite material is electroactive in the negative potential range due to the faradaic reduction process of C60 moieties. At less negative potentials, a high capacity current related to the presence of mesoporous carbon is observed. Under voltammetric conditions, this system exhibits a high capacitance equal to 359 F g−1 in the potential range of C60Pd reduction at 0.1 V s−1. This value is 3 times higher than that of the pure polymeric material. Moreover, the composite system is more stable than pristine C60Pd. Capacitance retention, in this case, is approximately 30% higher than that of the C60Pd polymer after 6000 charging/discharging cycles at current density of 6.7 A g−1.

Constructing a drug release model by central composite design to investigate the interaction between drugs and temperature-sensitive controlled release nanoparticles

To study the release behavior of a thermosensitive controlled release drug delivery system and construct a predictable mathematical model of drug release, poly(N-isopropylacrylamide-co-Allylamine) (P(NIPA-AL17)) and ploy(styrene sulfonate) (PSS) were functionalized on the surface of hollow mesoporous carbon nanoparticles (HMCNs) through layer-by-layer (LBL) assembly to construct a photothermal responsive controlled release system. A five-level four-factorial central composite design (CCD) was performed to investigate the relationship between four independent variables including drug loading (A), number of polymer layers (B), temperature (C) and vibration rate of the shaker (D), and three dependent response variables, including cumulative release over 1 h (Y1), cumulative release over 24 h (Y2) and the release rate constant k (Y3). The CCD results indicate that A and C significantly affect Y1 (P < 0.05). C significantly affects Y2 (P < 0.05). A and B is found to affect Y3 (P < 0.05) significantly. When C is below 39 °C, Y1 and Y2 decrease with the increase of A and B, and when C is above 39 °C, they increase with the increase of A and B; Y3 decreases as A and B increase; and D shows the least or even no influence on Y1, Y2 and Y3. The constructed predictable mathematical model will provide a scientific reference for the further development and application of photothermal responsive controlled-release preparations.

Customized multi-stimuli nanovehicles with dissociable ‘bomblets’ for photothermal-enhanced synergetic tumor therapy

Recently, the therapeutic effect of chemotherapy has been obviously impaired due to premature drug release, low tumor penetration, and multidrug resistance of nanoplatforms. In this paper, a novel multiple-sensitive drug delivery system (MC-ss-CDs) was developed by gating long-wavelength emitting carbon dots (CDs) on the openings of mesoporous carbon nanoparticles (MC) through disulfide bonds. The MC with excellent photothermal transition efficiency and high drug storage capacity for doxorubicin (DOX) was used as the delivery carrier. The CDs had multiple functions, including intelligent switching to hinder unwanted release, photothermal therapy (PTT) agents to improve the heat generation effect of MCs and bioimaging trackers to monitor drug delivery. The disulfide bonds, as the linkers between MC carriers and CDs, are stable under normal physical conditions and relatively labile under high GSH concentrations in the cytoplasm of tumor cells. After arriving at the tumor microenvironment, DOX/MC-ss-CDs can rapidly break into DOX/MC and CDs under high GSH concentrations. DOX/MC could realize efficient integration of PTT and chemotherapy on the surface of the tumor by stimuli-responsive DOX release and synergetic heating of MC and CDs. The small-sized CDs with excellent penetrating ability could effectively enter the deep tumor and realize NIR-triggered photothermal ablation. The DOX/MC-ss-CDs showed a chemophotothermal effect with a combination index of 0.38 in vitro and in vivo. Therefore, the DOX/MC-ss-CDs could be employed as a trackable nanovehicle for synergistic chemotherapy and PTT at different depths.

Muscle cytotoxicity and immuno-reactivity analysis of the porous carbon nanospheres fabricated by high temperature calcination

Carbon-based nanomaterials have a high specific surface area, biocompatibility, and controlled mesopore structures. These characteristics make carbon nanospheres excellent carriers for drugs, biological dyes, photosensitizers, etc. Nevertheless, little is known about the impact of topological features on the surface of carbon nanomaterials on their in vivo immunoreactivity. In this study, we fabricated mesoporous carbon nanoparticles (MCNs) and solvent-processable carbon vesicles (CVs) by high-temperature calcination. The hematoxylin and eosin (H&E) staining suggested CVs' relatively poor dispersion capacity compared to MCNs and carbon precursors (CPs), leading to more severe muscle inflammation and necrosis. Immunostaining and Fluorescence Activated Cell Sorter (FACS) analysis further showed that both MCNs and CVs triggered a transient immune response in transplanted muscle and muscle-draining lymph nodes, but did not alter muscle resistance to exogenous viruses. In conclusion, this study provides insights into how carbon nanoparticles modulate the activation of immune responses in vivo.

Template free synthesis of mesoporous carbon from fire cracker waste and designing of ZnO-Mesoporous carbon photocatalyst for dye (MO) degradation

The fire cracker waste materials are one of the reasons for environmental pollution and it’s very hazardous to human beings. Till today, not much attention has been given to its utility or recyclability. In the present work, we have first time reported the synthesis of mesoporous carbon nanoparticles (MCNPs) by using cost-free fire cracker waste having black columnar fluffy “snake-like” carbon using simple chemical activation and calcination method. The desired Zinc oxide–mesoporous carbon (ZMC) nanocomposites have been synthesized by precipitation and calcination method. Synthesized materials were characterized by XRD, FT-IR, UV–vis DRS, BET, PL, SEM, EDS and TEM. The above prepared nanocomposites were explored for their photocatalytic test under UV light irradiation. The photocatalytic degradation percentage of methyl orange (MO) dye using optimized Zinc oxide–mesoporous carbon-15 (ZMC15) nanocomposite reached 90 % after 120 min under UV light than the pristine ZnO. The cytotoxicity studies experimented on the gills of the freshwater fish Cirrhinus mrigala revealed that MO dye solution caused damage to gill architecture, whereas photodegraded dye solution was shown to be less toxic and did not modify the gill architecture structurally. These results demonstrated the importance of the desired material in concern with environmental issues.

A novel oil-water microemulsion strategy for controllable synthesis of large mesoporous carbon nanoparticles

Recently, the carbon nanoparticles with defined architecture, small particle diameter and large mesopore size, have aroused people's enormous interests on account of their laudable properties. Here, it is novel mesoporous carbon nanoparticles (MCNs) that have been successfully fabricated in a neoteric oil-water microemulsion system, which is developed to synchronously adjust the surface roughness, particle diameter, and large mesopore size through accommodating the emulsion polarity. Besides, pentanol as a cosurfactant not only significantly affects the evolution of mesopore size but also acts an vital role in the interfacial interaction between carbon precursors and soft templates, leading to the fluffy growth of particles. Interestingly, an extended swelling-penetration mechanism is subtly put forward to explain the formation and transformation of MCNs, which would provide a simple and unique ingenuity for this material species. Remarkably, to fulfill the multifunctional properties of such MCNs, MCNs-2 is further utilized as a fluorescent probe platform to detect mutated nucleic acids with high selectivity and low detection limit, as well as a medical carrier to work well in drug delivery system with high adsorption/release properties and extremely low cytotoxicity, which would empower it with luciferous prospects for the applications in biosensor and biomedical fields.

Catalytic Activity for ORR of Pt Supported on Ordered Mesoporous Carbon with Network Structure

IntroductionIn order to realize carbon neutrality, working toward becoming a hydrogen-based society using renewable energy is essential, and hydrogen fuel cell vehicles will be one of the key devices. For further widespread deployment of fuel cell vehicles, cost reduction and performance enhancement of polymer electrolyte fuel cell (PEFC) systems are urgently needed. Recently, Pt/C-based electrocatalysts using mesoporous carbon as a support material have attracted attention, because well-designed mesopores can act as “accessible pores,” in which direct contact between ionomer and Pt surface is avoided, while the transport of protons, oxygen and generated water is not suppressed. Ordered mesoporous carbon (OMC) with a uniform nanopore structure is one of the ideal candidate materials for a catalyst support with accessible pores. However, with conventional synthesis methods, the typical OMC primary particle size is on the order of micrometers, and mass transport within the nanopores could be a difficult issue. In the present study, we focused on the development of OMC nanoparticles with a network structure. By use of nonionic surfactant micelles with phenol-formaldehyde resole resin as a carbon source, we obtained OMC nanoparticles with a novel hierarchical network structure (ns-OMC). To the best of our knowledge, there are no reports of the synthesis of ordered mesoporous carbon nanoparticles with a rigid network structure. In this study, in addition to the effect of synthesis conditions on the ns-OMC structure, a newly developed technique for the selective deposition of Pt nanoparticles within the ns-OMC nanopores, and the ORR activity of the Pt/ns-OMC catalysts, will be discussed in detail.ExperimentalNs-OMC powder was synthesized with resol-nonionic surfactant micelles as a carbon source and structure directing agent. Resol-F127 (nonionic surfactant) micelles were synthesized by mixing phenol, formaldehyde, water and F127 with sodium hydroxide. After hydrothermal treatment of the mixture, the resulting solid was filtered and washed thoroughly and dried under vacuum. The obtained powder was carbonized at 700 ºC followed by annealing at 1000 ºC. Pt was deposited on the ns-OMC powder by the reverse micelle and colloid techniques. Cyclic voltammetry and linear sweep voltammetry were carried out in N2-saturated and O2-saturated 0.1 M HClO4 solution at 25 ºC using the conventional rotating disk electrode (RDE) technique. Potential step cycling measurements simulating load cycling between 0.6 V and 1.0 V vs. RHE were carried out according to the FCCJ protocol. Coating of the catalyst on a glassy carbon disk substrate was carried out by an electrospray (ES) coating technique developed by our group [1]. N2 adsorption measurement at liquid nitrogen temperature was carried out. The morphology of the Pt/ns-OMC was observed by scanning transmission electron microscope (STEM).Results and discussionAs seen in the STEM images of the ns-OMC powder (Figure 1), the network structure formed by connection of OMC primary nanoparticles to form developed macropores is clearly observed. The OMC nanoparticles were tightly connected via a thick necking structure. The primary particle size of the OMC and neck thickness were controllable via the resol-F127 micelle concentration and the temperature during the hydrothermal treatment. Highly ordered nanopores were observed on the surface of the OMC particles, with a pore size of ca. 5 nm and an interpore distance of ca. 8 nm. The nanopores and the network structure were stable even after high temperature annealing at 1400 ºC. The BET specific surface area for the ns-OMC annealed at 1000 ºC was 814 m2 g-1, and the BJH pore size distribution curve of the ns-OMC showed a mesopore peak at 4.5 nm, which is in good agreement with the STEM observation. When Pt was deposited on the ns-OMC support, most of the Pt particles, with diameters of 4 to 5 nm, were dispersed on the support and, interestingly, located inside or right above the nanopore entrances. Careful STEM measurements revealed that the Pt particles were not deposited deeply within the OMC nanopores, but most were deposited at relatively shallow positions. RDE measurements revealed that the Pt/ns-OMC catalysts showed higher specific activity and mass activity for the ORR and much higher stability for the ECSA values during potential step cycling measurements in comparison with a commercial Pt/CB catalyst. The higher catalytic activity and durability observed for the Pt/ns-OMC catalyst may be due to a near-ideal distance between neighboring Pt particles deposited on the novel support. Aggregation and sintering of the Pt particles were successfully suppressed due to the nanopore structure.[1] S. Cho, K. Tamoto and M. Uchida, Energy Fuels, 34, 14853 (2020).Acknowledgement: This work was supported by the ECCEED’30-FC project from NEDO. Figure 1

Mitochondria-targeting folic acid-modified nanoplatform based on mesoporous carbon and a bioactive peptide for improved colorectal cancer treatment

Oral colon-targeted drug delivery systems (OCDDs) are designed to deliver the therapeutic agents to colonic disease sites to improve the effectiveness of drug treatment, increase bioavailability, and reduce systemic side effects and are beneficial for the treatment of colorectal cancer (CRC) and inflammatory bowel disease (IBD). However, concerns about the biosafety of OCDDs are increasing, and changes in the physiological environment of the gastrointestinal tract can affect the therapeutic efficacy of the drug. Herein, we report about an orally administered colon-accumulating mitochondria-targeted drug delivery nanoplatform (M27-39@FA-MCNs), which was synthesized using the small peptide, M27-39, and folic acid (FA)-modified mesoporous carbon nanoparticles (FA-MCNs). The phenolic resin polymerized with phloroglucinol and formaldehyde (PF) was used for fabricating MCNs using a one-step soft-template method. Folic acid (FA) can be covalently combined with chitosan-modified MCNs to obtain FA-MCNs. The M27-39@FA-MCNs were stable with a spherical morphology and an average diameter of 129 nm. The cumulative release rate of M27-39@FA-MCNs in the artificial gastric fluid (pH = 1.2) and intestinal fluid (pH = 6.8) for 6 h was 87.77%. This nanoplatform maintains the advantages of both FA and MCNs to improve the bioactivity of M27-39 with high drug accumulation in colorectal tumor tissues and the ease of excretion, thus ameliorating its biosafety and targetability. Furthermore, M27-39@FA-MCNs induced tumor-cell apoptosis and inhibited tumor growth by disrupting mitochondrial energy metabolism and regulating the mitochondrial apoptosis signaling pathway and immune inflammatory response. Thus, such a mitochondria-targeting FA-modified nanoplatform based on mesoporous carbon and a bioactive peptide may provide a precise strategy for CRC treatment. Statement of significanceIn this study, we constructed an orally administered colon-accumulating mitochondria-targeted drug delivery nanoplatform (M27-39@FA-MCNs), which was synthesized using the small peptide (M27-39) and folic acid-modified mesoporous carbon nanoparticles (FA-MCNs). M27-39@FA-MCNs increased the targeting ability of M27-39 toward mitochondria and colon based on the properties of FA-MCNs; they also increased M27-39 accumulation and residence time in colon tumors. Oral administration of M27-39@FA-MCNs remarkably alleviated colorectal cancer (CRC) by targeting tumor cell mitochondria and interfering with the mitochondrial energy metabolism process, and inducing apoptosis related P53/Caspase-3 mitochondrial pathway activation. Therefore, M27-39@FA-MCNs may provide a safe and precise therapeutic strategy for CRC.

A mutually beneficial macrophages-mediated delivery system realizing photo/immune therapy.

The accumulation of nanomedicines in tumor tissues determines their therapeutic efficacy. We herein exploit the tropism of macrophages to improve the accumulation and retention time of nanomedicine at tumors. Interestingly, macrophages are not merely as transporters, but killers activated by nanomedicine. The system(M@C-HA/ICG) was established by decorating macrophages with hyaluronic acid-modified hollow mesoporous carbon (C) nanoparticles loading indocyanine green (ICG). Notably, C nanoparticles with superior photothermal conversion capability not merely guarantee the efficient delivery of ICG through high drug loading efficiency and inhibiting the premature leaky, but effectually activate the polarization of macrophages. The results exhibited that those activated macrophages could release pro-inflammatory cytokines (NO, TNF-α, IL-12), while M@C-HA/ICG afforded about 2-fold higher tumor accumulation compared with pure nanoparticle C-HA/ICG and produced heat and singlet oxygen (1O2) under irradiation of an 808nm laser, realizing the combination of photodynamic therapy (PDT), photothermal therapy (PTT) and cytokines-mediated immunotherapy. Specially, we also investigated the relationship of singlet oxygen (1O2) or temperature and tumor-killing activity for understanding the specific effectual procedure of PDT/PTT synergistic therapy. Overall, we firstly established an "all active" delivery system integrating the features of nanomedicine with biological functions of macrophages, providing a novel insight for cell-mediated delivery platform and tumor targeted multimodality anti-cancer therapy.

Understandings about functionalized porous carbon via scanning transmission x-ray microscopy (STXM) for high sulfur utilization in lithium-sulfur batteries

Functionalized porous carbons are necessary for the reversible operation of lithium-sulfur batteries (LSBs), however, their appropriate utilization and physicochemical states in the sulfur cathode are still unclear. Although numerous studies regarding distribution of sulfur in the pores of the carbon framework in the cathode have been reported, sulfur distribution and oxygen coverage on the carbon surface after sulfur infiltration have not been clearly investigated. In this study, we scrutinized the role of the pores in the oxygen-functionalized mesoporous carbon nanoparticle (O-MCN). Furthermore, we elaborated sulfur distribution, oxygen coverage, and pore utilization of O-MCN under the three different sulfur infiltration process. The soft x-ray scanning transmission x-ray microscopy (STXM) was used for the first time in the LSB system. The STXM enabled probing of local distribution of sulfur and the chemical nature of sulfur and oxygen in O-MCNs. Our findings provide a comprehensive understanding about how the sulfur infiltration process impacts the sulfur utilization during the redox reaction of sulfur in the oxygen-functionalized mesoporous carbon.

Simultaneous Determination of Adulterants in Dietary Food Supplements Using Multivariate Data Analysis after Preconcentration with Novel Nanosorbents and Chromatographic Measurement.

The increasing popularity of dietary supplements and, consequently, related adulteration emphasizes the rising need to examine the association of food supplements with fraud. Intentional or unintentional fraud in food supplements by hazardous chemicals compounds is a problem that many countries are struggling with. Much effort have been made to effectively and reliably control the quality of food supplements. Due to the importance of the subject, an analytical method for the simultaneous and reliable detection and quantitative determination of three key adulterants in dietary food supplements was developed. The proposed method benefits from analytical methods and multivariate calibration methods to progress the determination of adulterants in a complex matrix. HPLC assisted by multivariate curve resolution-alternating least square (MCR-ALS) analysis was used to detect adulterants in real samples after separation and preconcentration using novel mesoporous carbon nanoparticles. Solid-phase extraction (SPE) optimization was accomplished by central composite design (CCD). In order to obtain the best results, the MCR-ALS model was compared with the parallel factor analysis 2 (PARAFAC2) model and validated by estimation of linearity, detection limits, and recovery. The detection limits and linear dynamics were calculated as 1.5, 4.27, and 4.77 µg/mL, and 1-50, 5-20, and 5-20 µg/mL for caffeine, ephedrine, and fluoxetine, respectively. Mean recovery for determination of caffeine, ephedrine, and fluoxetine using the developed method was reported as 101.75, 91.7, and 92.36, respectively. The results showed that to avoid negative health outcomes associated with the excessive consumption of adulterated food supplements releasing such products should be carefully regulated. The developed method was validated using statistical factors and showed acceptable and reliable results. (1) The application of MCR-ALS coupled with HPLC-Diode-Array Detection data sets allowed the simultaneous identification and quantification of three key adulterants (caffeine, ephedrine, and fluoxetine) in dietary food supplements. (2) A small amount of the novel adsorbent was successfully used to preconcentrate the trace amounts of adulterants in samples. (3) This method benefits from the chemometrics tools and experimental design to significantly reduce the use of toxic solvents and complicated instruments to propose a less time-consuming method for quantification of multicomponents in the presence of uncalibrated interferents.

Nanoengineering of N-doped Mesoporous Carbon Nanoparticles with Adjustable Internal Cavities via Emulsion-Induced Assembly.

The preparation of mesoporous carbonaceous materials with particularly adjustable morphology is currently a hot area of research in mesoporous materials. Herein, a novel approach is reported for the construction of N-doped multicavity mesoporous carbon nanoparticles (NMMCNs) based on the “emulsion swelling–acid curing mechanism” using a nanoemulsion assembly method under a high-speed shearing force. Intriguingly, this approach adopted a novel acid (HCl) curing procedure. Impressively, the morphology evolution from an internal multicavity to a single cavity and then to a non-cavity interior structure could be accomplished by simply varying the synthesis parameters. Additionally, this synthesis approach ingeniously overcame the following problems: (i) technically, the employment of high temperatures and high pressures in traditional hydrothermal reaction curing environments is avoided; (ii) this approach removes the requirement for silicon coating, which provides a limited pyrolysis condition, to obtain a multi-chamber structure. Resveratrol (Res) is an insoluble natural medicine and was successfully loaded into NMMCNs, thereby the Res–NMMCNs delivery system was constructed. Importantly, the Res–NMMCNs delivery system could still retain the antitumor and antioxidant activity of Res in vitro.