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1.
Proc Natl Acad Sci U S A ; 121(28): e2403143121, 2024 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-38959041

RESUMEN

Currently, the nanofluidic synapse can only perform basic neuromorphic pulse patterns. One immediate problem that needs to be addressed to further its capability of brain-like computing is the realization of a nanofluidic spiking device. Here, we report the use of a poly(3,4-ethylenedioxythiophene) polystyrene sulfonate membrane to achieve bionic ionic current-induced spiking. In addition to the simulation of various electrical pulse patterns, our synapse could produce transmembrane ionic current-induced spiking, which is highly analogous to biological action potentials with similar phases and excitability. Moreover, the spiking properties could be modulated by ions and neurochemicals. We expect that this work could contribute to biomimetic spiking computing in solution.


Asunto(s)
Potenciales de Acción , Poliestirenos , Sinapsis , Potenciales de Acción/fisiología , Sinapsis/fisiología , Poliestirenos/química , Nanotecnología/métodos , Nanotecnología/instrumentación
2.
Electrophoresis ; 45(3-4): 327-332, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38010589

RESUMEN

Hand, foot, and mouth disease is a serious public health problem, and the main pathogen is enterovirus 71 (EV71). Its capsid assembly mechanism including capsid protein processing has been widely studied. Full and empty capsids have different immunological efficacy. Therefore, tracking full/empty capsid ratio throughout the EV71 production process is important to ensure consistent product quality and proper dosing response. The analysis of full/empty capsid ratio of intact virus has been widely reported as well. A variety of techniques have been employed to evaluate the full/empty capsid ratios. However, there has not been a rapid, reproducible, and robust assay to determine the full/empty capsid ratios of final and in-process products. In this study, a novel assay based on capillary zone electrophoresis was established. The separation of full and empty species could be achieved within 10 min and the ratio of peak areas was used to calculate the full/empty capsid ratio directly. The results showed good reproducibility and linearity for the determination of full/empty capsid ratios.


Asunto(s)
Enterovirus Humano A , Enterovirus Humano A/metabolismo , Reproducibilidad de los Resultados , Proteínas de la Cápside , Cápside/metabolismo , Procesamiento Proteico-Postraduccional
3.
Biomacromolecules ; 25(1): 89-103, 2024 01 08.
Artículo en Inglés | MEDLINE | ID: mdl-38056946

RESUMEN

Antimicrobial peptide mimics have been used to kill bacteria and construct antibacterial materials. Precise design and construction of chemical structure are essential for easy access to highly effective antimicrobial peptide mimics. Herein, cationic guanidinium-based polymers (PGXs) with varying hydrophobic structures were synthesized to explore the structure and antibacterial activity relationship of antimicrobial peptide mimics and to construct antibacterial implants. The effect of the hydrophobic chemical structure, including carbon chain length and configuration, on the antimicrobial activities against both Escherichia coli and Staphylococcus aureus was investigated. The antibacterial activities of PGXs improved with increasing alkyl chain length, and PGXs with a straight-chain hydrophobic structure exhibited better bactericidal activities than those with cyclic alkane and aromatic hydrocarbon. Furthermore, PGXs grafted with poly(dimethylsiloxane) (PDMS-PGXs) showed a similar bactericidal change tendency of PGXs in solution. Additionally, the PDMS-PGXs showed potent antibiofilm performance in vitro, which can inhibit bacterial infection in vivo as subcutaneous implants. This study may propose a basis for the precise design and construction of antibacterial materials and provide a promising way of designing biomedical devices and implants with bacterial infection-combating activities.


Asunto(s)
Polímeros , Infecciones Estafilocócicas , Humanos , Polímeros/farmacología , Polímeros/química , Guanidina/farmacología , Antibacterianos/farmacología , Antibacterianos/química , Péptidos Antimicrobianos , Escherichia coli , Pruebas de Sensibilidad Microbiana
4.
Macromol Rapid Commun ; : e2400196, 2024 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-38830612

RESUMEN

The utilization of two-component systems comprising camphorquinone (CQ) and aromatic amines has become prevalent in the photopolymerization. However, there are still concerns about the safety of this CQ/amine system, mainly because of the toxicity associated with the leaching of aromatic amines. In light of these concerns, this study aims to develop novel coinitiator combinations featuring CQ and amines which cannot be leached out of materials, enabling free radical polymerization of representative dentalmethacrylate resins under blue light irradiation. This approach involves the initial design and analysis of hydrogen donors with low C─H bond dissociation energy through molecular modeling. Subsequently, copolymerizable methacrylate functional groups are incorporated via chemical modification, allowing it to act as both coinitiator and copolymerization monomer to achieve low migrationand leachability properties. This work presents, for the first time, the synthesis of the innovative coinitiator and compares its performance with the benchmark CQ/ethyl-4-dimethylaminobenzoate (EDB)-based photoinitiation system (PIS). The results demonstrate the effectiveness of the newly proposed PIS. Finally, an in-depth investigation is conducted into the reaction mechanism associated with this PIS through molecular orbital calculations and electron spin resonance studies.

5.
Angew Chem Int Ed Engl ; 63(24): e202402853, 2024 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-38598262

RESUMEN

In the development of dendritic cell (DC) vaccines, the maturation of DCs is a critical stage. Adjuvants play a pivotal role in the maturation of DCs, with a major concern being to ensure both efficacy and safety. This study introduces an innovative approach that combines high efficacy with safety through the synthesis of micro-adjuvants grafted with copolymers of 2-(methacrylamido) glucopyranose (MAG) and methacryloxyethyl trimethyl ammonium chloride (DMC). The utilization of metal-free surface-initiated atom transfer radical polymerization enables the production of safe and recyclable adjuvants. These micrometer-sized adjuvants surpass the optimal size range for cellular endocytosis, enabling the retrieval and reuse of them during the ex vivo maturation process, mitigating potential toxicity concerns associated with the endocytosis of non-metabolized nanoparticles. Additionally, the adjuvants exhibit a "micro-ligand-mediated maturation enhancement" effect for DC maturation. This effect is influenced by the shape of the particle, as evidenced by the distinct promotion effects of rod-like and spherical micro-adjuvants with comparable sizes. Furthermore, the porous structure of the adjuvants enables them to function as cargo-carrying "micro-shuttles", releasing antigens upon binding to DCs to facilitate efficient antigen delivery.


Asunto(s)
Adyuvantes Inmunológicos , Células Dendríticas , Polimerizacion , Células Dendríticas/metabolismo , Células Dendríticas/inmunología , Adyuvantes Inmunológicos/química , Adyuvantes Inmunológicos/farmacología , Adyuvantes Inmunológicos/síntesis química , Vacunas/química , Vacunas/inmunología , Tamaño de la Partícula , Ratones , Animales , Polímeros/química , Polímeros/farmacología , Polímeros/síntesis química
6.
Anal Chem ; 95(48): 17912-17919, 2023 12 05.
Artículo en Inglés | MEDLINE | ID: mdl-37972240

RESUMEN

The organic photoelectrochemical transistor (OPECT) has been proven to be a promising platform to study the rich light-matter-bio interplay toward advanced biomolecular detection, yet current OPECT is highly restrained to its intrinsic electronic amplification. Herein, this work first combines chemical amplification with electronic amplification in OPECT for dual-amplified bioanalytics with high current gain, which is exemplified by human immunoglobulin G (HIgG)-dependent sandwich immunorecognition and subsequent alkaline phosphatase (ALP)-mediated chemical redox cycling (CRC) on a metal-organic framework (MOF)-derived BiVO4/WO3 gate. The target-dependent redox cycling of ascorbic acid (AA) acting as an effective electron donor could lead to an amplified modulation against the polymer channel, as indicated by the channel current. The as-developed bioanalysis could achieve sensitive HIgG detection with a good analytical performance. This work features the dual chemical and electronic amplification for OPECT bioanalysis and is expected to stimulate further interest in the design of CRC-assisted OPECT bioassays.


Asunto(s)
Técnicas Biosensibles , Estructuras Metalorgánicas , Humanos , Técnicas Electroquímicas , Oxidación-Reducción , Polímeros , Límite de Detección
7.
Macromol Rapid Commun ; 44(7): e2200881, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36756898

RESUMEN

Molecular recognition is an important process in life activities where specificity is the key. However, the method to gain specificity are often complex and time-consuming. Herein, a novel, versatile, and effective way is developed to obtain cell-specific glycosurfaces by surface-initiated Cu-mediated reversible deactivation radical polymerization (Cu-RDRP) in an open to air fashion. Mammalian cells are used for the first time as live templates to realize cell-sugar monomer-aptation-polymerization which can produce cell-specific glycosurfaces. Both epithelial cell adhesion molecule (EpCAM) positive cells L929 and EpCAM negative cells Hela as models are used to acquire two cell-specific glycosurfaces, which can distinguish template-cells from others. The strategy is effective and convenient without the need of fixative pretreatment of cells. It is found that the specific capture does not rely on EpCAM antibodies, and the specificity is related to the composition and chain sequence of the glycopolymer brushes rather than surface morphology. In addition, these glycosurfaces keep the ability to identify the target cells after ten regenerative treatments, which provides another advantage for practical applications.


Asunto(s)
Carbohidratos , Polímeros , Animales , Molécula de Adhesión Celular Epitelial , Azúcares , Polimerizacion , Mamíferos
8.
Nano Lett ; 22(18): 7572-7578, 2022 09 28.
Artículo en Inglés | MEDLINE | ID: mdl-36083029

RESUMEN

Developing highly efficient advanced battery deionization (BDI) electrode materials at a low cost is vital for seawater desalination. Herein, a high-efficiency wood-based BDI electrode has been fabricated for seawater desalination, benefiting from the self-supporting three-dimensional (3D) nanoporous structure and rich redox-active sites. The finely tuned rich electrochemical redox active C═O groups on the surface of the wood electrode derived from the facile thermochemical conversion of lignin play a crucial role in the Faradaic cation removal dynamics of BDI. Coupling the 3D wood electrode and a polyaniline-modified wood electrode as the cathode and anode, an all-wood-electrode-based deionization battery has been successfully assembled with a state-of-the-art ion removal capacity of up to 164 mg g-1 in seawater. Our work reported an example of utilizing wood as the BDI electrode via fine-tuning the redox-active sites, demonstrating a novel resource utilization pathway of converting cheap biomass into BDI electrodes for highly efficient seawater desalination.


Asunto(s)
Nanoporos , Purificación del Agua , Electrodos , Lignina , Cloruro de Sodio , Purificación del Agua/métodos , Madera
9.
J Am Chem Soc ; 144(38): 17558-17566, 2022 09 28.
Artículo en Inglés | MEDLINE | ID: mdl-36112975

RESUMEN

Measuring the activity of low-abundance enzymes, down to a few molecules in one living cell, is important but challenging to elucidate their biological function. Here, an electrochemical molecule trap is established at the tip of a nanopipette with an electrochemical detector, in which the diffusion of the molecules away from the electrochemical detector is prevented by electro-osmotic flow (EOF). Accordingly, a limited amount of enzymes is trapped to continuously catalyze the conversion of the substrate to generate a sufficient amount of the byproduct hydrogen peroxide for electrochemical measurements. The resistive pulse sensing of the enzymes in single liposomes validates the detection sensitivity down to 15 molecules. Using this ultrasensitive electrochemical strategy, the activity of 60 sphingomyelinase molecules inside single unstimulated living J774 cells is measured, which was hardly detected by previous methods. The established electrochemical molecule trap-based sensing approach opens the door toward single-molecule electrochemical detection in one living cell. This success will solve the long-standing problem regarding the study of the activity of low-abundance proteins in cells in their native physiological state and greatly enhance the understanding of the roles of proteins in cellular behavior.


Asunto(s)
Peróxido de Hidrógeno , Esfingomielina Fosfodiesterasa , Catálisis , Técnicas Electroquímicas/métodos , Peróxido de Hidrógeno/química , Liposomas , Nanotecnología/métodos
10.
Environ Microbiol ; 24(3): 1395-1410, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-35064734

RESUMEN

Streptococcus mutans (S. mutans) is the principal etiological agent in cariogenesis because of its ability to metabolize sucrose into extracellular polysaccharides (EPS). The response regulators GcrR and VicR could regulate EPS metabolism, but with opposing regulatory functions. However, the cooperative interactions between gcrR and vicR regulating sucrose-selective EPS metabolism have not been fully elucidated. First, we constructed several dual-mutant strains (vicR + gcrR+, vicR and gcrR overexpression; vicR + gcrR-, vicR overexpression and gcrR deficient; ASvicRgcrR+, vicR low-expression and gcrR overexpression; ASvicRgcrR-, vicR low-expression and gcrR deficient) to clarify gtfB/gtfC expression levels were modulated by gcrR regardless of the vicR gene expression levels. Next, we found gcrR deletion mutant (SmugcrR) displayed obvious auto-aggregation and bacterial cells were densely packed in enriched EPS induced by sucrose. In the contrast, SmugcrR biofilm showed very little carbohydrate-dependent aggregation in the absence of sucrose. The presence of sucrose amplifies the negative regulation of gcrR acting as a 'switch-off'. After sucrose induction, dexA gene expression was significantly enhanced in gcrR overexpression mutant (SmugcrR+). Furthermore, GcrR was shown to directly bind to the promoter region of the dexA gene. Taken together, our results reveal that GcrR interacts with VicR to block EPS biosynthesis via polysaccharide digestion by DexA, and that this process is induced in a sucrose-selective manner. Hence, targeting GcrR is a potential strategy for the management of dental caries.


Asunto(s)
Caries Dental , Streptococcus mutans , Proteínas Bacterianas/metabolismo , Biopelículas , Regulación Bacteriana de la Expresión Génica , Humanos , Streptococcus mutans/genética , Sacarosa/metabolismo
11.
Cells Tissues Organs ; 211(1): 57-72, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-34525477

RESUMEN

Periodontitis is an inflammatory disease resulting from subgingival microorganisms. Human periodontal ligament stem cells (hPDLSCs) can be applied in periodontal tissue regeneration. This study investigated the effect of hPDLSC-derived extracellular vesicles (EVs) on periodontitis. hPDLSC-derived EVs were isolated and identified. The murine model of periodontitis was established by ligation, and the cell model of periodontitis was established by treatment of macrophages with lipopolysaccharide (LPS). The effects of EVs on macrophage pyroptosis and periodontal inflammatory injury were measured by the means of HE staining, detection of LDH content, CCK-8 assay, Calcein-AM/PI staining, ELISA, Western blot, as well as measurement of caspase-1, SOD, and MDA. miR-590-3p expression was detected using RT-qPCR. miR-590-3p expression was then intervened to validate the effect of miR-590-3p on macrophage pyroptosis. The binding relationship between miR-590-3p and TLR4 was verified using dual-luciferase assay. Functional rescue experiment was performed to validate the role of TLR4 in macrophage pyroptosis. The results showed that inflammatory levels and macrophage pyroptosis were enhanced in the in vivo and in vitro models of periodontitis, evidenced by the increased NLRP3, GSDMD-N, caspase-1, IL-1ß, IL-18, TNF-α, and MDA and decreased IL-10 and SOD. EVs alleviated periodontal inflammatory injury and macrophage pyroptosis. Physiologically, EVs carried miR-590-3p into macrophages to upregulate miR-590-3p expression and thereby suppress TLR4 transcription. miR-590-3p silencing or TLR4 overexpression reduced the inhibitory effect of EVs on macrophage pyroptosis. Collectively, EVs carried miR-590-3p into macrophages to subsequently inhibit TLR4 transcription, thereby reducing macrophage pyroptosis and alleviating periodontal inflammatory injury.


Asunto(s)
Vesículas Extracelulares , MicroARNs , Periodontitis , Animales , Caspasas/metabolismo , Caspasas/farmacología , Vesículas Extracelulares/metabolismo , Humanos , Macrófagos , Ratones , MicroARNs/genética , MicroARNs/metabolismo , Ligamento Periodontal/metabolismo , Periodontitis/metabolismo , Piroptosis , Células Madre/metabolismo , Superóxido Dismutasa/metabolismo , Superóxido Dismutasa/farmacología , Receptor Toll-Like 4/metabolismo
12.
Biomacromolecules ; 23(5): 2170-2183, 2022 05 09.
Artículo en Inglés | MEDLINE | ID: mdl-35465654

RESUMEN

The emergence of "superbugs" is not only problematic and potentially lethal for infected subjects but also poses serious challenges for the healthcare system. Although existing antibacterial agents have been effective in some cases, the side effects and biocompatibility generally present difficulties. The development of new antibacterial agents is therefore urgently required. In this work, we have adapted a strategy for the improvement of poly(hexamethylene guanidine) hydrochloride (PHMG), a common antibacterial agent. This involves copolymerization of separate monomer units in varying ratios to find the optimum ratio of the hydrocarbon to guanidine units for antibacterial activity. A series of these copolymers, designated as PGB, was synthesized. By varying the guanidine/hydrophobic ratio and the copolymer molecular weight, a structure-optimized PGB was identified that showed broad-spectrum antibacterial activity and excellent biocompatibility in solution. In an antibacterial assay, the copolymer with the optimum composition (hydrophobic unit content 25%) inhibited >99% Staphylococcus aureus and was compatible with mammalian cells. A polyurethane emulsion containing this PGB component formed transparent, flexible films (PGB-PU films) on a wide range of substrate surfaces, including soft polymers and metals. The PGB-PU films showed excellent bacteriostatic efficiency against nosocomial drug-resistant bacteria, such as Pseudomonas aeruginosa and methicillin-resistant S. aureus (MRSA). It is concluded that our PGB polymers can be used as bacteriostatic agents generally and in particular for the design of antibacterial surfaces in medical devices.


Asunto(s)
Staphylococcus aureus Resistente a Meticilina , Animales , Humanos , Alcanos , Antibacterianos/química , Antibacterianos/farmacología , Guanidina/química , Guanidina/farmacología , Guanidinas/farmacología , Mamíferos , Pruebas de Sensibilidad Microbiana , Polímeros/química , Polímeros/farmacología
13.
Nanotechnology ; 33(35)2022 Jun 09.
Artículo en Inglés | MEDLINE | ID: mdl-35616242

RESUMEN

Decades have witnessed rapid progress of polymeric materials for vascular embolic or chemoembolic applications. Commercially available polymeric embolics range from gelatin foam to synthetic polymers such as poly(vinyl alcohol). Current systems under investigation include tunable, bioresorbable microspheres composed of chitosan or poly(ethylene glycol) derivatives,in situgelling liquid embolics with improved safety profiles, and radiopaque embolics that are trackablein vivo. In this paper, we proposed a concept of 'responsive embolization'. Sevelamer, clinically proved as an inorganic phosphate binder, was ground into nanoparticles. Sevelamer nanoparticle is highly mobile and capable of swelling and aggregating in the presence of endogenous inorganic phosphate, thereby effectively occluding blood flow in the vessel as it was administered as an embolic agent for interventional therapy. Moreover, citrated sevelamer nanoparticles delayed the aggregation, preferable to penetrate deeply into the capillary system. On the rabbit VX2 liver cancer model, both sevelamer particles aggregates occlude the tumor feeding artery, but backflow was found for the pristine one, thereby citrate passivation of sevelamer nanoparticles endows it have potential from 'bench to bedside' as a new type of vascular embolic.


Asunto(s)
Embolización Terapéutica , Nanopartículas , Animales , Microesferas , Fosfatos , Polímeros , Conejos , Sevelamer
14.
Macromol Rapid Commun ; 43(20): e2200376, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35726483

RESUMEN

The dual-initiator technique allows the polymerization of different monomers from orthogonal polymerization mechanisms to obtain block copolymers (BCPs). In this study, it is attempted to combine photoiniferter living free radical polymerization and organocatalytic ring-opening polymerization (ROP) to design a hydroxyl-functionalized carbamodithioate, i.e., 4-(hydroxymethyl)benzyl diethylcarbamodithioate (HBDC), which can integrate photoiniferter polymerization of acrylamide monomers and ROP of cyclic carbonates. As a proof of concept, the monomer applicability is further extended to acrylates and lactones. The results confirm that the two polymerization systems are experimentally compatible in a stepwise sequence as well as in a simultaneous one-pot process to synthesize BCPs. It is reasonable to assume that HBDC can allow for simple and efficient one-pot access to well-defined BCPs from a larger range of monomers, which is more advantageous from the operational, economical, and environmental points of view.


Asunto(s)
Carbonatos , Polímeros , Polimerizacion , Lactonas , Radicales Libres , Catálisis , Acrilatos , Acrilamidas
15.
Macromol Rapid Commun ; 43(8): e2100920, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35138013

RESUMEN

A photocontrolled reversible addition-fragmentation chain transfer (RAFT) process is developed by initiating polymerization through a 1,3-diaminopropane-triethylborane (DAPTB)-diphenyl iodonium salt (Ph2 I+ ) complex (DAPTB/Ph2 I+ ) under ambient temperature and atmospheric conditions. Upon demand, this air-stable DAPTB/Ph2 I+ complex is photolyzed to liberate a reactive triethylborane that consumes atmospheric oxygen and generates ethyl radicals, which initiate and mediate RAFT polymerization. Controlled RAFT polymerization is thus achieved without any prior deoxygenation using a novel RAFT chain transfer agent, BP-FSBC, which contains both benzophenone and sulfonyl fluoride moieties. Furthermore, the kinetics of polymerization reveal that the reaction process is rapid, and well-defined polymers are produced by a 61% conversion of 2-hydroxyethyl acrylate (HEA) within 7 min and 77% conversion of N,N-dimethylacrylamide (DMA) within 10.5 min. The temporal and spatial control of this photopolymerization is also demonstrated by an "on/off" switch of UV irradiation and a painting-on-a-surface approach, respectively. In addition, active chain ends are demonstrated by preparing block copolymers by chain extension and click sulfur(VI)-fluoride exchange postreaction using RAFT-derived macrochain transfer agents.


Asunto(s)
Polímeros , Azufre , Oxígeno , Polimerizacion
16.
Nature ; 531(7594): 329-34, 2016 Mar 17.
Artículo en Inglés | MEDLINE | ID: mdl-26958837

RESUMEN

Many biopolymers, including polysaccharides, must be translocated across at least one membrane to reach their site of biological function. Cellulose is a linear glucose polymer synthesized and secreted by a membrane-integrated cellulose synthase. Here, in crystallo enzymology with the catalytically active bacterial cellulose synthase BcsA-BcsB complex reveals structural snapshots of a complete cellulose biosynthesis cycle, from substrate binding to polymer translocation. Substrate- and product-bound structures of BcsA provide the basis for substrate recognition and demonstrate the stepwise elongation of cellulose. Furthermore, the structural snapshots show that BcsA translocates cellulose via a ratcheting mechanism involving a 'finger helix' that contacts the polymer's terminal glucose. Cooperating with BcsA's gating loop, the finger helix moves 'up' and 'down' in response to substrate binding and polymer elongation, respectively, thereby pushing the elongated polymer into BcsA's transmembrane channel. This mechanism is validated experimentally by tethering BcsA's finger helix, which inhibits polymer translocation but not elongation.


Asunto(s)
Celulosa/biosíntesis , Celulosa/metabolismo , Glucosiltransferasas/química , Glucosiltransferasas/metabolismo , Membranas Intracelulares/metabolismo , Celulosa/química , Cristalografía por Rayos X , Glucosa/metabolismo , Membranas Intracelulares/química , Modelos Moleculares , Movimiento , Estructura Secundaria de Proteína , Proteolípidos/química , Proteolípidos/metabolismo , Rhodobacter sphaeroides/enzimología , Especificidad por Sustrato
17.
Environ Res ; 204(Pt C): 112177, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-34717945

RESUMEN

Reverse thermally induced separation (RTIPS) was used to obtain a separation membrane with a better internal structure for a higher water flux and a surface that could easily form a hydration layer. In comparison to the traditional modification method, this work focused on the aspect that the internal structure obtained by changing the membrane-making method provided easier adhesion conditions for the dopamine/TiO2 hybrid nanoparticles (DA/TiO2 HNPs) obtained by biomimetic mineralization. It provided a basis for exploring the variation in adhesion with the water bath temperature and the amount of titanium added through the study of turbidity point, SEM images, water contact angle, thermogravimetric test, EDX, AFM, XPS, FTIR and other test results. The SEM images proved that the membrane obtained through the RTIPS method had a porous surface and spongy internal structure, furthermore, additional polymers were adsorbed. Use of EDX demonstrated that biomimetic mineralization prevented the production of agglomerated titanium dioxide. XPS and FTIR spectra confirmed the introduction and immobilization of HNP aggregation. Moreover, a decrease in the surface roughness and water contact angle further suggested an improvement in the hydrophilicity of the modified membrane. The introduction of HNP at a higher water bath temperature helped increase the water flux up to ten times, moreover, the oil-water separation efficiency could still reach over 99.50%. Lastly, a cycle test of the modified membrane under the optimal conditions helped confirm that the membrane forming conditions at this time could provide a better environment for the formation of the hydrophilic layer, which was conducive to the recycling of the separation membrane. In summary, more fixed more hydrophilic particles could be obtained through the RTIPS method based on biomimetic mineralization to prevent the accumulation of titanium dioxide, thus helping improve permeability and anti-fouling of the membrane.


Asunto(s)
Biónica , Membranas Artificiales , Polímeros/química , Sulfonas
18.
Int J Mol Sci ; 23(18)2022 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-36142516

RESUMEN

The objectives of this study were to investigate the effects of a novel method using flavonoids to inhibit Streptococcus mutans (S. mutans), Candida albicans (C. albicans) and dual-species biofilms and to protect enamel hardness in a biofilm-based caries model for the first time. Several flavonoids, including baicalein, naringenin and catechin, were tested. Gold-standard chlorhexidine (CHX) and untreated (UC) groups served as controls. Optimal concentrations were determined by cytotoxicity assay. Biofilm MTT, colony-forming-units (CFUs), biofilm biomass, lactic acid and polysaccharide production were evaluated. Real-time-polymerase-chain reaction (qRT-PCR) was used to determine gene expressions in biofilms. Demineralization of human enamel was induced via S. mutans-C. albicans biofilms, and enamel hardness was measured. Compared to CHX and UC groups, the baicalein group achieved the greatest reduction in S. mutans, C. albicans and S. mutans-C. albicans biofilms, yielding the least metabolic activity, polysaccharide synthesis and lactic acid production (p < 0.05). The biofilm CFU was decreased in baicalein group by 5 logs, 4 logs, 5 logs, for S. mutans, C. albicans and S. mutans-C. albicans biofilms, respectively, compared to UC group. When tested in a S. mutans-C. albicans in vitro caries model, the baicalein group substantially reduced enamel demineralization under biofilms, yielding an enamel hardness that was 2.75 times greater than that of UC group. Hence, the novel baicalein method is promising to inhibit dental caries by reducing biofilm formation and protecting enamel hardness.


Asunto(s)
Catequina , Caries Dental , Biopelículas , Candida albicans , Catequina/farmacología , Clorhexidina/farmacología , Caries Dental/prevención & control , Esmalte Dental , Flavanonas , Flavonoides/farmacología , Flavonoides/uso terapéutico , Dureza , Humanos , Ácido Láctico/farmacología , Polisacáridos/farmacología , Streptococcus mutans
19.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 53(2): 250-255, 2022 Mar.
Artículo en Zh | MEDLINE | ID: mdl-35332725

RESUMEN

Objective: To explore the microbial diversity and community structure of dental plaques in orthodontic patients with invisible appliances and fixed appliances and to study the differences. Methods: Ten orthodontic patients wearing invisible appliances (I) and ten wearing fixed appliances (F) were recruited. Dental plaques were collected from both buccal (B) and lingual (L) sides. Based on 16S rDNA, 40 dental plaque samples were analyzed after Illumina sequencing. Results: The microbial diversity, abundance and evenness of the FB group were significantly higher than those of the IB and IL groups (P<0.05), while the FL group showed substantial individual differences. The community structures were generally similar among the four groups, but significant differences in the relative abundance of some bacteria were found. The IB group showed higher abundances of Actinomycetes and Rosella (P<0.05), which were considered to be involved in dental caries and periodontal diseases. Some key communities showing significant differences were significantly enriched in the FB group, including Coprobacillus, Bifidobacterium, Enterobacterium, Lactobacillus, etc.. Conclusion: Dental plaques in patients wearing invisible appliances and fixed appliances showed significantly different microbial abundance, diversity and composition, which may be involved in orthodontic complications such as dental caries and periodontal diseases. Orthodontic patients need strengthened measures for oral hygiene maintenance, no matter what kind of appliances they wear.


Asunto(s)
Caries Dental , Placa Dental , Bacterias/genética , Caries Dental/etiología , Humanos , Aparatos Ortodóncicos/efectos adversos , Aparatos Ortodóncicos Fijos/efectos adversos
20.
Small ; 17(29): e2100789, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-34142432

RESUMEN

Metal-phenolic networks (MPNs) are an emerging class of supramolecular surface modifiers with potential use in various fields including drug delivery. Here, the development of a unique MPN-integrated core-satellite nanosystem (CS-NS) is reported. The "core" component of CS-NS comprises a liposome loaded with EDTA (a metal ion chelator) in the aqueous core and DiR (a near-infrared photothermal transducer) in the bilayer. The "satellite" component comprises mesoporous silica nanoparticles (MSNs) encapsulating doxorubicin and is coated with a Cu2+ -tannic acid MPN. Liposomes and MSNs self-assemble into the CS-NS through adhesion mediated by the MPN. When irradiated with an 808 nm laser, CS-NS liberated the entrapped EDTA, leading to Cu2+ chelation and subsequent disassembly of the core-satellite nanostructure. Photo-conversion from the large assembly to the small constituent particles proceeded within 5 min. Light-triggered CS-NS disassembly enhanced the carrier and cargo penetration and accumulation in tumor spheroids in vitro and in orthotopic murine mammary tumors in vivo. CS-NS is long circulating in the blood and conferred improved survival outcomes to tumor-bearing mice treated with light, compared to controls. These results demonstrate an MPN-integrated multistage nanosystem for improved solid tumor treatment.


Asunto(s)
Nanopartículas , Neoplasias , Animales , Línea Celular Tumoral , Doxorrubicina , Sistemas de Liberación de Medicamentos , Liberación de Fármacos , Humanos , Liposomas , Ratones , Neoplasias/tratamiento farmacológico
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