Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 11.370
Filtrar
Mais filtros

Intervalo de ano de publicação
1.
Exp Cell Res ; 435(1): 113926, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38228225

RESUMO

The present research aims to evaluate the efficacy of Silibinin-loaded mesoporous silica nanoparticles (Sil@MSNs) immobilized into polylactic-co-glycolic acid/Collagen (PLGA/Col) nanofibers on the in vitro proliferation of adipose-derived stem cells (ASCs) and cellular senescence. Here, the fabricated electrospun PLGA/Col composite scaffolds were coated with Sil@MSNs and their physicochemical properties were examined by FTIR, FE-SEM, and TGA. The growth, viability and proliferation of ASCs were investigated using various biological assays including PicoGreen, MTT, and RT-PCR after 21 days. The proliferation and adhesion of ASCs were supported by the biological and mechanical characteristics of the Sil@MSNs PLGA/Col composite scaffolds, according to FE- SEM. PicoGreen and cytotoxicity analysis showed an increase in the rate of proliferation and metabolic activity of hADSCs after 14 and 21 days, confirming the initial and controlled release of Sil from nanofibers. Gene expression analysis further confirmed the increased expression of stemness markers as well as hTERT and telomerase in ASCs seeded on Sil@MSNs PLGA/Col nanofibers compared to the control group. Ultimately, the findings of the present study introduced Sil@MSNs PLGA/Col composite scaffolds as an efficient platform for long-term proliferation of ASCs in tissue engineering.


Assuntos
Nanofibras , Alicerces Teciduais , Adesão Celular , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Silibina/farmacologia , Alicerces Teciduais/química , Nanofibras/química , Colágeno/farmacologia , Colágeno/química , Engenharia Tecidual , Células-Tronco , Proliferação de Células , Células Cultivadas , Compostos Orgânicos
2.
Nano Lett ; 24(2): 566-575, 2024 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-37962055

RESUMO

Optical biosensors based on micro/nanofibers are highly valuable for probing and monitoring liquid environments and bioactivity. Most current optical biosensors, however, are still based on glass, semiconductors, or metallic materials, which might not be fully suitable for biologically relevant environments. Here, we introduce biocompatible and flexible microfibers from lotus silk as microenvironmental monitors that exhibit waveguiding of intrinsic fluorescence as well as of coupled light. These features make single-filament monitors excellent building blocks for a variety of sensing functions, including pH probing and detection of bacterial activity. These results pave the way for the development of new and entirely eco-friendly, potentially multiplexed biosensing platforms.


Assuntos
Técnicas Biossensoriais , Nanofibras , Técnicas Biossensoriais/métodos , Seda , Semicondutores , Bactérias
3.
Nano Lett ; 24(11): 3404-3412, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38451852

RESUMO

Assembling metal-organic frameworks (MOFs) into ordered multidimensional porous superstructures promises the encapsulation of enzymes for heterogeneous biocatalysts. However, the full potential of this approach has been limited by the poor stability of enzymes and the uncontrolled assembly of MOF nanoparticles onto suitable supports. In this study, a novel and exceptionally robust Ni-imidazole-based MOF was synthesized in water at room temperature, enabling in situ enzyme encapsulation. Based on this MOF platform, we developed a DNA-directed assembly strategy to achieve the uniform placement of MOF nanoparticles onto bacterial cellulose nanofibers, resulting in a distinctive "branch-fruit" structure. The resulting hybrid materials demonstrated remarkable versatility across various catalytic systems, accommodating natural enzymes, nanoenzymes, and multienzyme cascades, thus showcasing enormous potential as universal microbioreactors. Furthermore, the hierarchical composites facilitated rapid diffusion of the bulky substrate while maintaining the enzyme stability, with ∼3.5-fold higher relative activity compared to the traditional enzyme@MOF immobilized in bacterial cellulose nanofibers.


Assuntos
Enzimas Imobilizadas , Nanofibras , Enzimas Imobilizadas/química , Celulose , Frutas , DNA/química
4.
Nano Lett ; 24(29): 8920-8928, 2024 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-38874568

RESUMO

Blood-contacting medical devices (BCDs) require antithrombotic, antibacterial, and low-friction surfaces. Incorporating a nanostructured surface with the functional hydrogel onto BCD surfaces can enhance the performances; however, their fabrication remains challenging. Here, we introduce a straightforward method to fabricate a multifunctional hydrogel-based nanostructure on BCD surfaces using O-carboxymethyl chitosan-based short nanofibers (CMC-SNFs). CMC-SNFs, fabricated via electrospinning and cutting processes, are easily sprayed and entangled onto the BCD surface. The deposited CMC-SNFs form a robust nanoweb layer via fusion at the contact area of the nanofiber interfaces. The superhydrophilic CMC-SNF nanoweb surface creates a water-bound layer that effectively prevents the nonspecific adhesion of bacteria and blood cells, thereby enhancing both antimicrobial and antithrombotic performances. Furthermore, the CMC-SNF nanoweb exhibits excellent lubricity and durability on the bovine aorta. The demonstration results of the CMC-SNF coating on catheters and sheaths provide evidence of its capability to apply multifunctional surfaces simply for diverse BCDs.


Assuntos
Quitosana , Hidrogéis , Nanofibras , Quitosana/química , Quitosana/análogos & derivados , Nanofibras/química , Animais , Hidrogéis/química , Bovinos , Propriedades de Superfície , Humanos , Materiais Revestidos Biocompatíveis/química , Materiais Revestidos Biocompatíveis/farmacologia , Antibacterianos/farmacologia , Antibacterianos/química
5.
J Am Chem Soc ; 146(17): 11991-11999, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38639465

RESUMO

The complex dynamics and transience of assembly pathways in living systems complicate the understanding of these molecular to nanoscale processes. Current technologies are unable to track the molecular events leading to the onset of assembly, where real-time information is imperative to correlate their rich biology. Using a chemically designed pro-assembling molecule, we map its transformation into nanofibers and their fusion with endosomes to form hollow fiber clusters. Tracked by phasor-fluorescence lifetime imaging (phasor-FLIM) in epithelial cells (L929, A549, MDA-MB 231) and correlative light-electron microscopy and tomography (CLEM), spatiotemporal splicing of the assembly events shows time-correlated metabolic dysfunction. The biological impact begins with assembly-induced endosomal disruption that reduces glucose transport into the cells, which, in turn, stymies mitochondrial respiration.


Assuntos
Imagem Óptica , Humanos , Endossomos/metabolismo , Nanofibras/química , Linhagem Celular , Animais
6.
Anal Chem ; 96(15): 5940-5950, 2024 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-38562013

RESUMO

Peptide-based supramolecules exhibit great potential in various fields due to their improved target recognition ability and versatile functions. However, they still suffer from numerous challenges for the biopharmaceutical analysis, including poor self-assembly ability, undesirable ligand-antibody binding rates, and formidable target binding barriers caused by ligand crowding. To tackle these issues, a "polyvalent recognition" strategy employing the CD20 mimotope peptide derivative NBD-FFVLR-GS-WPRWLEN (acting on the CDR domains of rituximab) was proposed to develop supramolecular nanofibers for target antibody recognition. These nanofibers exhibited rapid self-assembly within only 1 min and robust stability. Their binding affinity (179 nM) for rituximab surpassed that of the monomeric peptide (7 µM) by over 38-fold, highlighting that high ligand density and potential polyvalent recognition can efficiently overcome the target binding barriers of traditional supramolecules. Moreover, these nanofibers exhibited an amazing "instantaneous capture" rate (within 15 s), a high recovery (93 ± 3%), and good specificity for the target antibody. High-efficiency enrichment of rituximab was achieved from cell culture medium with good recovery and reproducibility. Intriguingly, these peptide nanofibers combined with bottom-up proteomics were successful in tracking the deamidation of asparagine 55 (from 10 to 16%) on the rituximab heavy chain after 21 day incubation in human serum. In summary, this study may open up an avenue for the development of versatile mimotope peptide supramolecules for biorecognition and bioanalysis of biopharmaceuticals.


Assuntos
Produtos Biológicos , Nanofibras , Humanos , Rituximab , Nanofibras/química , Ligantes , Reprodutibilidade dos Testes , Peptídeos/química
7.
Anal Chem ; 96(3): 1345-1353, 2024 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-38190289

RESUMO

Designing a metal-organic framework (MOF)-derived nanozyme with highly dispersed active sites and high catalytic activity as well as robust structure for colorimetric biosensing of diverse biomolecules remains a substantial challenge. Here, an MOF-derived highly dispersed and pure α-cobalt confined in a nitrogen-doped carbon nanofiber (α-Co@NCNF) nanozyme with superior glucose oxidase (GOD)- and peroxidase (POD)-like activities was constructed for colorimetric assay of multiple biomolecules. Specifically, the α-Co@NCNF nanozyme was synthesized, utilizing in situ electrospinning Co-MOFs into polyacrylonitrile nanofiber (PAN) followed by a pyrolysis process. Taking advantage of the in situ electrospinning strategy, the α-Co nanoparticles were confined in continuous porous NCNF to restrict the growth and prevent the aggregation and oxidation during the pyrolysis process. The resulting special structure considerably improved the enzyme-like performance. A series of experiments validate that the enzyme-like activity of the α-Co@NCNF nanozyme was superior to that of Co@CoO@NCNF (derivatives from Co-MOFs grown on the surface of PAN nanofiber) and nature enzymes. Furthermore, α-Co@NCNF nanozyme-based colorimetric biosensing was developed for monitoring glucose, hydrogen peroxide (H2O2), and glutathione (GSH) and the corresponding linear ranges are 0.1-50 and 50-900 µM and 5-55 and 0.1-20 µM accompanied by the corresponding low detection of 0.03, 1.66, and 0.03 µM. The proposed method for the construction of α-Co@NCNF nanozyme with dual enzyme-like properties provides a new insight for designing novel nanozymes and has prospects for application in colorimetric biosensing.


Assuntos
Estruturas Metalorgânicas , Nanofibras , Peróxido de Hidrogênio , Estruturas Metalorgânicas/química , Carbono/química , Nitrogênio/química , Cobalto , Antioxidantes , Colorimetria/métodos
8.
Anal Chem ; 96(19): 7772-7779, 2024 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-38698542

RESUMO

There is growing attention focused toward the problems of ecological sustainability and food safety raised from the abuse of herbicides, which underscores the need for the development of a portable and reliable sensor for simple, rapid, and user-friendly on-site analysis of herbicide residues. Herein, a novel multifunctional hydrogel composite is explored to serve as a portable and flexible sensor for the facile and efficient analysis of atrazine (ATZ) residues. The hydrogel electrode is fabricated by doping graphite-phase carbon nitride (g-C3N4) into the aramid nanofiber reinforced poly(vinyl alcohol) hydrogel via a simple solution-casting procedure. Benefiting from the excellent electroactivity and large specific surface area of the solid nanoscale component, the prepared hydrogel sensor is capable of simple, rapid, and sensitive detection of ATZ with a detection limit down to 0.002 ng/mL and per test time less than 1 min. After combination with a smartphone-controlled portable electrochemical analyzer, the flexible sensor exhibited satisfactory analytical performance for the ATZ assay. We further demonstrated the applications of the sensor in the evaluation of the ATZ residues in real water and soil samples as well as the user-friendly on-site point-of-need detection of ATZ residues on various agricultural products. We envision that this flexible and portable sensor will open a new avenue on the development of next-generation analytical tools for herbicide monitoring in the environment and agricultural products.


Assuntos
Atrazina , Técnicas Eletroquímicas , Herbicidas , Hidrogéis , Atrazina/análise , Herbicidas/análise , Hidrogéis/química , Técnicas Eletroquímicas/instrumentação , Grafite/química , Eletrodos , Limite de Detecção , Nitrilas/química , Nitrilas/análise , Nanofibras/química , Poluentes Químicos da Água/análise
9.
Small ; 20(9): e2307585, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37849034

RESUMO

The combination of multiple orthogonal interactions enables hierarchical complexity in self-assembled nanoscale materials. Here, efficient supramolecular polymerization of DNA origami nanostructures is demonstrated using a multivalent display of small molecule host-guest interactions. Modification of DNA strands with cucurbit[7]uril (CB[7]) and its adamantane guest, yielding a supramolecular complex with an affinity of order 1010 m-1 , directs hierarchical assembly of origami monomers into 1D nanofibers. This affinity regime enables efficient polymerization; a lower-affinity ß-cyclodextrin-adamantane complex does not promote extended structures at a similar valency. Finally, the utility of the high-affinity CB[7]-adamantane interactions is exploited to enable responsive enzymatic actuation of origami nanofibers assembled using peptide linkers. This work demonstrates the power of high-affinity CB[7]-guest recognition as an orthogonal axis to drive self-assembly in DNA nanotechnology.


Assuntos
Adamantano , Nanofibras , Nanoestruturas , Nanotecnologia , DNA
10.
Small ; 20(3): e2305100, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37688343

RESUMO

Diabetic chronic wounds pose significant clinical challenges due to their characteristic features of impaired extracellular matrix (ECM) function, diminished angiogenesis, chronic inflammation, and increased susceptibility to infection. To tackle these challenges and provide a comprehensive therapeutic approach for diabetic wounds, the first coaxial electrospun nanocomposite membrane is developed that incorporates multifunctional copper peroxide nanoparticles (n-CuO2 ). The membrane's nanofiber possesses a unique "core/sheath" structure consisting of n-CuO2 +PVP (Polyvinylpyrrolidone)/PCL (Polycaprolactone) composite sheath and a PCL core. When exposed to the wound's moist environment, PVP within the sheath gradually disintegrates, releasing the embedded n-CuO2 . Under a weakly acidic microenvironment (typically diabetic and infected wounds), n-CuO2 decomposes to release H2 O2 and Cu2+ ions and subsequently produce ·OH through chemodynamic reactions. This enables the anti-bacterial activity mediated by reactive oxygen species (ROS), suppressing the inflammation while enhancing angiogenesis. At the same time, the dissolution of PVP unveils unique nano-grooved surface patterns on the nanofibers, providing desirable cell-guiding function required for accelerated skin regeneration. Through meticulous material selection and design, this study pioneers the development of functional nanocomposites for multi-modal wound therapy, which holds great promise in guiding the path to healing for diabetic wounds.


Assuntos
Diabetes Mellitus , Nanocompostos , Nanofibras , Humanos , Cicatrização , Pele/lesões , Nanocompostos/química , Nanofibras/química , Inflamação
11.
Small ; 20(27): e2309269, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38308170

RESUMO

3D printing and electrospinning are versatile techniques employed to produce 3D structures, such as scaffolds and ultrathin fibers, facilitating the creation of a cellular microenvironment in vitro. These two approaches operate on distinct working principles and utilize different polymeric materials to generate the desired structure. This review provides an extensive overview of these techniques and their potential roles in biomedical applications. Despite their potential role in fabricating complex structures, each technique has its own limitations. Electrospun fibers may have ambiguous geometry, while 3D-printed constructs may exhibit poor resolution with limited mechanical complexity. Consequently, the integration of electrospinning and 3D-printing methods may be explored to maximize the benefits and overcome the individual limitations of these techniques. This review highlights recent advancements in combined techniques for generating structures with controlled porosities on the micro-nano scale, leading to improved mechanical structural integrity. Collectively, these techniques also allow the fabrication of nature-inspired structures, contributing to a paradigm shift in research and technology. Finally, the review concludes by examining the advantages, disadvantages, and future outlooks of existing technologies in addressing challenges and exploring potential opportunities.


Assuntos
Nanofibras , Impressão Tridimensional , Engenharia Tecidual , Alicerces Teciduais , Nanofibras/química , Engenharia Tecidual/métodos , Humanos , Alicerces Teciduais/química , Biomimética/métodos , Regeneração , Animais , Materiais Biomiméticos/química
12.
Small ; 20(23): e2307603, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38213024

RESUMO

Bacterial cellulose/oxidized bacterial cellulose nanofibrils (BC/oxBCNFs) macro-fibers are developed as a novel scaffold for vascular tissue engineering. Utilizing a low-speed rotary coagulation spinning technique and precise solvent control, macro-fibers with a unique heterogeneous structure with dense surface and porous core are created. Enhanced by a polydopamine (PDA) coating, these macro-fibers offer robust mechanical integrity, high biocompatibility, and excellent cell adhesion. When cultured with endothelial cells (ECs) and smooth muscle cells (SMCs), the macro-fibers support healthy cell proliferation and exhibit a unique spiral SMC alignment, demonstrating their vascular suitability. This innovative strategy opens new avenues for advances in tissue engineering.


Assuntos
Celulose , Nanofibras , Engenharia Tecidual , Alicerces Teciduais , Engenharia Tecidual/métodos , Nanofibras/química , Alicerces Teciduais/química , Celulose/química , Humanos , Miócitos de Músculo Liso/citologia , Proliferação de Células/efeitos dos fármacos , Adesão Celular , Células Endoteliais/citologia , Células Endoteliais da Veia Umbilical Humana , Indóis/química , Polímeros
13.
Small ; 20(30): e2308335, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38420895

RESUMO

Tumor-derived exosomes (TDEs) induced extracellular microenvironment has recently been validated to be critical for tumor progression and metastasis, however, remodeling it for oncotherapy still remains a major challenge due to difficulty in regulation of TDEs secretion. Herein, the supramolecular chiral nanofibers, composed of L/D-phenylalanine derivates (L/D-Phe) and linear hyaluronic acid (HA), are successfully employed to construct TDEs induced anti-tumor extracellular microenvironment. The left-handed L-Phe @HA nanofibers significantly inhibit TDEs secretion into extracellular microenvironment, which results in suppression of tumor proliferation and metastasis in vitro and vivo. Biological assays and theoretical modeling reveal that these results are mainly attributed to strong adsorption of the key exosomes transporters (Ras-related protein Rab-27A and synaptosome-associated protein 23) on left-handed L-Phe @HA nanofibers via enhanced stereoselective interaction, leading to degradation and phosphorylated dropping of exosomes transporters. Subsequently, transfer function of exosomes transporters is limited, which causes remarkable inhibition of TDEs secretion. These findings provide a promising novel insight of chiral functional materials to establish an anti-tumor extracellular microenvironment via regulation of TDEs secretion.


Assuntos
Exossomos , Nanofibras , Microambiente Tumoral , Nanofibras/química , Exossomos/metabolismo , Microambiente Tumoral/efeitos dos fármacos , Humanos , Linhagem Celular Tumoral , Animais , Ácido Hialurônico/química , Proliferação de Células/efeitos dos fármacos
14.
Small ; 20(26): e2311802, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38258398

RESUMO

Conductive polymers are recognized as ideal candidates for the development of noninvasive and wearable sensors for real-time monitoring of potassium ions (K+) in sweat to ensure the health of life. However, the low ion-to-electron transduction efficiency and limited active surface area hamper the development of high-performance sensors for low-concentration K+ detection in the sweat. Herein, a wearable K+ sensor is developed by tailoring the nanostructure of polypyrrole (PPy), serving as an ion-to-electron transduction layer, for accurately and stably tracing the K+ fluctuation in human sweat. The PPy nanostructures can be tailored from nanospheres to nanofibers by controlling the supramolecular assembly process during PPy polymerization. Resultantly, the ion-to-electron transduction efficiency (17-fold increase in conductivity) and active surface area (1.3-fold enhancement) are significantly enhanced, accompanied by minimized water layer formation. The optimal PPy nanofibers-based K+ sensor achieved a high sensitivity of 62 mV decade-1, good selectivity, and solid stability. After being integrated with a temperature sensor, the manufactured wearable sensor realized accurate monitoring of K+ fluctuation in the human sweat.


Assuntos
Nanofibras , Polímeros , Potássio , Pirróis , Dispositivos Eletrônicos Vestíveis , Nanofibras/química , Pirróis/química , Polímeros/química , Potássio/química , Potássio/análise , Humanos , Técnicas Biossensoriais/métodos , Elétrons , Íons , Suor/química , Condutividade Elétrica
15.
Small ; 20(26): e2309868, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38259052

RESUMO

Critical-sized segmental long bone defects represent a challenging clinical dilemma in the management of battlefield and trauma-related injuries. The residual bone marrow cavity of damaged long bones contains many bone marrow mesenchymal stem cells (BMSCs), which provide a substantial source of cells for bone repair. Thus, a three-dimensional (3D) vertically aligned nanofiber scaffold (VAS) is developed with long channels and large pore size. The pore of VAS toward the bone marrow cavity after transplantation, enables the scaffolds to recruit BMSCs from the bone marrow cavity to the defect area. In vivo, it is found that VAS can significantly shorten gap distance and promote new bone formation compared to the control and collagen groups after 4 and 8 weeks of implantation. The single-cell sequencing results discovered that the 3D nanotopography of VAS can promote BMSCs differentiation to chondrocytes and osteoblasts, and up-regulate related gene expression, resulting in enhancing the activities of bone regeneration, endochondral ossification, bone trabecula formation, bone mineralization, maturation, and remodeling. The Alcian blue and bone morphogenetic protein 2 (BMP-2) immunohistochemical staining verified significant cartilage formation and bone formation in the VAS group, corresponding to the single-cell sequencing results. The study can inspire the design of next-generation scaffolds for effective long-bone regeneration is expected by the authors.


Assuntos
Regeneração Óssea , Diferenciação Celular , Condrogênese , Células-Tronco Mesenquimais , Nanofibras , Osteogênese , Alicerces Teciduais , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Nanofibras/química , Alicerces Teciduais/química , Animais
16.
Small ; 20(4): e2304119, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37759420

RESUMO

Although antibiotic is still the main choice for antibacteria both in hospital and community, phototherapy has become a possibly one of the alternative approaches in the treatment of microbe-associated infections nowadays because of its considerable potential in effective eradication of pathogenic bacteria. However, overwhelming reactive oxygen species (ROS) generated from phototherapy inevitably provoke an inflammatory response, complicating the healing process. To address this outstanding issue, a MXene-decorated nanofibrious is devised that not only yield localized heat but also elevate ROS levels under near-infrared laser exposure ascribed to the synergistic photothermal/photodynamic effect, for potent bacterial inactivation. After being further loaded with aspirin, the nanofibrous membranes exhibit benign cytocompatibility, boosting cell growth and suppressing the (nuclear factor kappa-B ( NF-κB) signaling pathways through RNA sequencing analysis, indicating an excellent anti-inflammatory effect. Interestingly, in vivo investigations also corroborate that the nanofibrous membranes accelerate infectious cutaneous regeneration by efficiently killing pathogenic bacteria, promoting collagen deposition, boosting angiogenesis, and dampening inflammatory reaction via steering NF-κB pathway. As envisaged, this work furnishes a decorated nanofibrous membrane with programmed antibacterial and anti-inflammatory effects for remedy of refractory bacteria-invaded wound regeneration.


Assuntos
NF-kappa B , Nanofibras , Nitritos , Elementos de Transição , NF-kappa B/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Cicatrização , Anti-Inflamatórios/farmacologia , Antibacterianos/farmacologia
17.
Small ; 20(24): e2307963, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38183362

RESUMO

pH-dependent peptide biomaterials hold tremendous potential for cell delivery and tissue engineering. However, identification of responsive self-assembling sequences with specified secondary structure remains a challenge. In this work, An experimental procedure based on the one-bead one-compound (OBOC) combinatorial library is developed to rapidly screen self-assembling ß-sheet peptides at neutral aqueous solution (pH 7.5) and disassemble at weak acidic condition (pH 6.5). Using the hydrophobic fluorescent molecule thioflavin T (ThT) as a probe, resin beads displaying self-assembling peptides show fluorescence under pH 7.5 due to the insertion of ThT into the hydrophobic domain, and are further cultured in pH 6.5 solution. The beads with extinguished fluorescence are selected. Three heptapeptides are identified that can self-assemble into nanofibers or nanoparticles at pH 7.5 and disassemble at pH 6.5. P1 (LVEFRHY) shows a rapid acid response and morphology transformation with pH modulation. Changes in the charges of histidine and hydrophobic phenyl motif of phenylalanine may play important roles in the formation of pH-responsive ß-sheet nanofiber. This high-throughput screening method provides an efficient way to identify pH-dependent ß-sheet self-assembling peptide and gain insights into structural design of such nanomaterials.


Assuntos
Peptídeos , Concentração de Íons de Hidrogênio , Peptídeos/química , Conformação Proteica em Folha beta , Ensaios de Triagem em Larga Escala/métodos , Nanofibras/química , Interações Hidrofóbicas e Hidrofílicas , Benzotiazóis/química
18.
Small ; 20(24): e2309164, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38175832

RESUMO

Attempts are made to design a system for sustaining the delivery of copper ions into diabetic wounds and induce angiogenesis with minimal dose-dependent cytotoxicity. Here, a dual drug-delivery micro/nanofibrous core-shell system is engineered using polycaprolactone/sodium sulfated alginate-polyvinyl alcohol (PCL/SSA-PVA), as core/shell parts, by emulsion electrospinning technique to optimize sustained delivery of copper oxide nanoparticles (CuO NP). Herein, different concentrations of CuO NP (0.2, 0.4, 0.8, and 1.6%w/w) are loaded into the core part of the core-shell system. The morphological, biomechanical, and biocompatibility properties of the scaffolds are fully determined in vitro and in vivo. The 0.8%w/w CuO NP scaffold reveals the highest level of tube formation in HUVEC cells and also upregulates the pro-angiogenesis genes (VEGFA and bFGF) expression with no cytotoxicity effects. The presence of SSA and its interaction with CuO NP, and also core-shell structure sustain the release of the nanoparticles and provide a non-toxic microenvironment for cell adhesion and tube formation, with no sign of adverse immune response in vivo. The optimized scaffold significantly accelerates diabetic wound healing in a rat model. This study strongly suggests the 0.8%w/w CuO NP-loaded PCL/SSA-PVA as an excellent diabetic wound dressing with significantly improved angiogenesis and wound healing.


Assuntos
Cobre , Células Endoteliais da Veia Umbilical Humana , Nanofibras , Cicatrização , Cobre/química , Cicatrização/efeitos dos fármacos , Animais , Nanofibras/química , Humanos , Emulsões/química , Neovascularização Fisiológica/efeitos dos fármacos , Diabetes Mellitus Experimental/tratamento farmacológico , Alicerces Teciduais/química , Ratos , Nanopartículas/química , Masculino , Ratos Sprague-Dawley , Poliésteres/química , Angiogênese
19.
Small ; 20(18): e2308833, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38185768

RESUMO

Topical hemostatic agents are preferred for application to sensitive bleeding sites because of their immediate locoregional effects with less tissue damage. However, the majority of commercial hemostatic agents fail to provide stable tissue adhesion to bleeding wounds or act as physical barriers against contaminants. Hence, it has become necessary to investigate biologically favorable materials that can be applied and left within the body post-surgery. In this study, a dual-sided nanofibrous dressing for topical hemostasis is electrospun using a combination of two protein materials: bioengineered mussel adhesive protein (MAP) and silk fibroin (SF). The wound-adhesive inner layer is fabricated using dihydroxyphenylalanine (DOPA)-containing MAP, which promotes blood clotting by aggregation of hemocytes and activation of platelets. The anti-adhesive outer layer is composed of alcohol-treated hydrophobic SF, which has excellent spinnability and mechanical strength for fabrication. Because both proteins are fully biodegradable in vivo and biocompatible, the dressing would be suitable to be left in the body. Through in vivo evaluation using a rat liver damage model, significantly reduced clotting time and blood loss are confirmed, successfully demonstrating that the proposed dual-sided nanofibrous dressing has the right properties and characteristics as a topical hemostatic agent having dual functionality of hemostasis and physical protection.


Assuntos
Antibacterianos , Bandagens , Hemostasia , Hemostáticos , Nanofibras , Animais , Nanofibras/química , Hemostasia/efeitos dos fármacos , Hemostáticos/química , Hemostáticos/farmacologia , Antibacterianos/farmacologia , Antibacterianos/química , Ratos , Fibroínas/química , Fibroínas/farmacologia , Bivalves/química , Proteínas/química , Seda/química , Ratos Sprague-Dawley
20.
Small ; 20(29): e2400399, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38607266

RESUMO

To address the issue of bacterial growth on fresh-cut fruits, this paper reports the synthesis of nanosized γ-cyclodextrin metal-organic frameworks (CD-MOFs) using an ultrasound-assisted method and their application as carriers of limonene for antibacterial active packaging. The effects of the processing parameters on the morphology and crystallinity of the CD-MOFs are investigated, and the results prove that the addition of methanol is the key to producing nanosized CD-MOFs. The limonene loading content of the nanosized CD-MOFs can reach approximately 170 mg g-1. The sustained-release behaviors of limonene in the CD-MOFs are evaluated. Molecular docking simulations reveal the distribution and binding sites of limonene in the CD-MOFs. CD-MOFs are deposited on the surfaces of polycaprolactone (PCL) nanofibers via an immersion method, and limonene-loaded CD-MOF@PCL nanofibers are prepared. The morphology, crystallinity, thermal stability, mechanical properties, and antibacterial activity of the nanofibers are also studied. The nanofiber film effectively inhibits bacterial growth and prolongs the shelf life of fresh-cut apples. This study provides a novel strategy for developing antibacterial active packaging materials based on CD-MOFs and PCL nanofibers.


Assuntos
Frutas , Limoneno , Estruturas Metalorgânicas , Nanofibras , Poliésteres , gama-Ciclodextrinas , Limoneno/química , Limoneno/farmacologia , Nanofibras/química , Poliésteres/química , Estruturas Metalorgânicas/química , Estruturas Metalorgânicas/farmacologia , gama-Ciclodextrinas/química , Frutas/química , Terpenos/química , Terpenos/farmacologia , Antibacterianos/farmacologia , Antibacterianos/química , Simulação de Acoplamento Molecular
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa