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1.
Int J Mol Sci ; 22(16)2021 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-34445516

RESUMO

In this study, we prepared core-sheath nanofiber membranes (CSNFMs) with silver nanoparticles (Ag NPs) embedding in the polylactic acid (PLA) nanofiber sheath and hyaluronic acid (HA) in the nanofiber core. The PLA/Ag NPs sheath provides mechanical support as well as anti-bacterial and anti-inflammatory properties. The controlled release of HA from the core could exert anti-adhesion effects to promote tendon sliding while reducing fibroblast attachment. From the microfibrous structural nature of CSNFMs, they function as barrier membranes to reduce fibroblast penetration without hampering nutrient transports to prevent post-operative peritendinous adhesion. As the anti-adhesion efficacy will depend on release rate of HA from the core as well as Ag NP from the sheath, we fabricated CSNFMs of comparable fiber diameter, but with thick (Tk) or thin (Tn) sheath. Similar CSNFMs with thick (Tk+) and thin (Tn+) sheath but with embedded Ag NPs in the sheath were also prepared. The physico-chemical properties of the barrier membranes were characterized in details, together with their biological response including cell penetration, cell attachment and proliferation, and cytotoxicity. Peritendinous anti-adhesion models in rabbits were used to test the efficacy of CSNFMs as anti-adhesion barriers, from gross observation, histology, and biomechanical tests. Overall, the CSNFM with thin-sheath and Ag NPs (Tn+) shows antibacterial activity with low cytotoxicity, prevents fibroblast penetration, and exerts the highest efficacy in reducing fibroblast attachment in vitro. From in vivo studies, the Tn+ membrane also shows significant improvement in preventing peritendinous adhesions as well as anti-inflammatory efficacy, compared with Tk and Tn CSNFMs and a commercial adhesion barrier film (SurgiWrap®) made from PLA.


Assuntos
Antibacterianos/administração & dosagem , Ácido Hialurônico/administração & dosagem , Poliésteres/química , Prata/química , Traumatismos dos Tendões/tratamento farmacológico , Células 3T3 , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Modelos Animais de Doenças , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Ácido Hialurônico/química , Ácido Hialurônico/farmacologia , Nanopartículas Metálicas , Camundongos , Testes de Sensibilidade Microbiana , Nanofibras/química , Espectroscopia Fotoeletrônica , Coelhos , Traumatismos dos Tendões/cirurgia , Aderências Teciduais/prevenção & controle
2.
J Chem Phys ; 155(5): 055101, 2021 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-34364337

RESUMO

Artificial amyloid-like nanofibers formed from short peptides are emerging as new supramolecular structures for catalysis and advanced materials. In this work, we analyze, by means of computational approaches, the preferred atomistic fibrillar architectures that result from the self-assembly of polar NY7, NF7, SY7, SF7, and GY7 peptides into steric zippers formed by two ß-sheets (describing an individual steric zipper) and by four ß-sheets. For all heptapeptides, except GY7, parallel ß-sheet organizations with polar residues packed at the steric zipper appear to be the preferred assemblies for the two ß-sheets system due to the formation of a strong network of hydrogen bonds. For GY7, however, an antiparallel organization with glycine at the steric zipper is the most stable one. The preferred architecture is mostly conserved when enlarging our model from two to four ß-sheets. The present work shows that the relative stability of different architectures results from a delicate balance between peptide composition, side chain hydrophobicity, and non-covalent interactions at the interface and provides the basis for a rational design of new improved artificial prion-inspired materials.


Assuntos
Proteínas Amiloidogênicas/química , Nanofibras/química , Oligopeptídeos/química , Ligação de Hidrogênio , Simulação de Dinâmica Molecular , Conformação Proteica em Folha beta , Termodinâmica
3.
Chem Commun (Camb) ; 57(64): 7863-7868, 2021 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-34287441

RESUMO

Drawing on independent work carried out by academic and industrial researchers using the immobilized TEMPO catalyst SiliaCat TEMPO, in this study we show how shifting the carboxylation process mediated by TEMPO in solution to a process mediated by the above-mentioned hybrid sol-gel catalyst allows the synthesis of insoluble polysaccharide nanofibers of superior quality, eliminating waste. This will dramatically reduce the polysaccharide nanofiber production costs opening the route to large-scale production and uptake of these versatile nanofibers in a variety of functional products where their use has been limited by high cost. The results of this study will be useful for catalysis and biotechnology researchers as well as for chemistry educators teaching green chemistry, nanochemistry, and catalysis using the outcomes of recent research.


Assuntos
Óxidos N-Cíclicos/química , Nanofibras/química , Polissacarídeos/química , Configuração de Carboidratos , Radicais Livres/química , Humanos , Oxirredução , Tamanho da Partícula
4.
AAPS PharmSciTech ; 22(6): 205, 2021 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-34286391

RESUMO

Drug-loaded electrospun fibers have attracted increasing attention as a promising wound dressing material due to their capability of preventing from infections and inflammation and maintaining an appropriate environment for wound healing. In this study, polylactic acid (PLA), which is widely used in wound management, was chosen as electrospinnable polymer. A triterpene extract (TE) from the outer bark of birch known for its anti-inflammatory, antiviral, antibacterial, and wound healing effects was chosen to produce TE-loaded PLA electrospun fibers for wound dressing. A binary solvent system of dichloromethane (DCM) and dimethyl sulfoxide (DMSO) was employed, and the ratio of the solvents was optimized for preparing smooth and uniform fibers. The morphology of TE-loaded PLA electrospun fibers was investigated by scanning electron microscopy (SEM). The entrapment of TE in PLA fibers was confirmed by confocal laser scanning microscopy (CLSM). Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) were used to analyze the solid state of TE in PLA fibers. The release behavior of TE was assayed by a shaking flask method for a period of 96 h. The results revealed that TE-loaded electrospun PLA microfibers could be reliably prepared and are promising future candidates in wound therapy.


Assuntos
Bandagens , Betula/química , Nanofibras/química , Casca de Planta/química , Poliésteres/síntese química , Triterpenos/síntese química , Antibacterianos/análise , Antibacterianos/síntese química , Química Farmacêutica/métodos , Nanofibras/análise , Extratos Vegetais/análise , Extratos Vegetais/síntese química , Poliésteres/análise , Triterpenos/análise
5.
Methods Mol Biol ; 2320: 65-73, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34302648

RESUMO

In this chapter, we introduce the method for fabricating thick and anisotropic cardiac tissue for heart regeneration. Aligned and biodegradable nanofiber can be prepared by electrospinning Food and Drug Administration-approved poly (lactic-co-glycolic acid) on a rotating drum. After the nanofibers are transferred on to a polydimethylsiloxane frame, the cardiomyocytes could be plated on the nanofiber to form thick and anisotropic cardiac tissue rapidly. Cardiac tissue-like construct could be easily created by one-step method, and transplanted onto the hearts of myocardium infarction models and lead to their functional recovery.


Assuntos
Infarto do Miocárdio/terapia , Miócitos Cardíacos/citologia , Nanofibras/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Animais , Anisotropia , Células Cultivadas , Masculino , Miocárdio/citologia , Ratos , Ratos Nus , Engenharia Tecidual/métodos , Tecidos Suporte/química
6.
Nat Commun ; 12(1): 4494, 2021 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-34301935

RESUMO

Self-assembling peptides have shown tremendous potential in the fields of material sciences, nanoscience, and medicine. Because of the vast combinatorial space of even short peptides, identification of self-assembling sequences remains a challenge. Herein, we develop an experimental method to rapidly screen a huge array of peptide sequences for self-assembling property, using the one-bead one-compound (OBOC) combinatorial library method. In this approach, peptides on beads are N-terminally capped with nitro-1,2,3-benzoxadiazole, a hydrophobicity-sensitive fluorescence molecule. Beads displaying self-assembling peptides would fluoresce under aqueous environment. Using this approach, we identify eight pentapeptides, all of which are able to self-assemble into nanoparticles or nanofibers. Some of them are able to interact with and are taken up efficiently by HeLa cells. Intracellular distribution varied among these non-toxic peptidic nanoparticles. This simple screening strategy has enabled rapid identification of self-assembling peptides suitable for the development of nanostructures for various biomedical and material applications.


Assuntos
Nanofibras/química , Nanoestruturas/química , Biblioteca de Peptídeos , Peptídeos/química , Dicroísmo Circular , Técnicas de Química Combinatória/métodos , Células HeLa , Ensaios de Triagem em Larga Escala/métodos , Humanos , Ligação de Hidrogênio , Microscopia Eletrônica de Transmissão , Nanofibras/ultraestrutura , Nanoestruturas/ultraestrutura , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
7.
Int J Mol Sci ; 22(14)2021 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-34299308

RESUMO

In bone surgery and orthopedics, bioresorbable materials can be helpful in bone repair and countering post-op infections. Explicit antibacterial activity, osteoinductive and osteoconductive effects are essential to achieving this objective. Nonwoven electrospun (ES) fibers are receiving the close attention of physicians as promising materials for wound dressing and tissue engineering; potentially, in high contrast with dense materials, ES mats hamper regeneration of the bone extracellular matrix to a lesser extent. The use of the compositions of inherently biodegradable polyesters (poly(ε-caprolactone) PCL, poly(lactoglycolide), etc.), calcium phosphates and antibiotics is highly prospective, but the task of forming ES fibers from such compositions is complicated by the incompatibility of the main organic and inorganic ingredients, polyesters and calcium phosphates. In the present research we report the synthesis of hydroxyapatite (HAp) nanoparticles with uniform morphology, and demonstrate high efficiency of the block copolymer of PCL and poly(ethylene phosphoric acid) (PEPA) as an efficient compatibilizer for PCL/HAp mixtures that are able to form ES fibers with improved mechanical characteristics. The materials obtained in the presence of vancomycin exhibited incremental drug release against Staphylococcus aureus (St. aureus).


Assuntos
Antibacterianos/química , Substitutos Ósseos/química , Hidroxiapatitas/química , Antibacterianos/administração & dosagem , Fenômenos Biomecânicos , Liberação Controlada de Fármacos , Humanos , Técnicas In Vitro , Teste de Materiais , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Nanofibras/química , Nanofibras/ultraestrutura , Nanopartículas/química , Nanopartículas/ultraestrutura , Poliésteres/química , Polietilenos/química , Staphylococcus aureus/efeitos dos fármacos , Vancomicina/administração & dosagem , Vancomicina/química , Difração de Raios X
8.
Life Sci ; 282: 119602, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34217765

RESUMO

The application of electroactive scaffolds can be promising for bone tissue engineering applications. In the current paper, we aimed to fabricate an electro-conductive scaffold based on carbon nanofibers (CNFs) containing ferrous sulfate. FeSO4·7H2O salt with different concentrations 5, 10, and 15 wt%, were blended with polyacrylonitrile (PAN) polymer as the precursor and converted to Fe2O3/CNFs nanocomposite by electrospinning and heat treatment. The characterization was conducted using SEM, EDX, XRD, FTIR, and Raman methods. The results showed that the incorporation of Fe salt induces no adverse effect on the nanofibers' morphology. EDX analysis confirmed that the Fe ions are uniformly dispersed throughout the CNF mat. FTIR spectroscopy showed the interaction of Fe salt with PAN polymer. Raman spectroscopy showed that the incorporation of FeSO4·7H2O reduced the ID/IG ratio, indicating more ordered carbon in the synthesized nanocomposite. Electrical resistance measurement depicted that, although the incorporation of ferrous sulfate reduced the electrical conductivity, the conductive is suitable for electrical stimulation. The in vitro studies revealed that the prepared nanocomposites were cytocompatible and only negligible toxicity (less than 10%) induced by CNFs/Fe2O3 fabricated from PAN FeSO4·7H2O 15%. Although various nanofibrous composite fabricated with Fe NPs have been evaluated for tissue engineering applications, CNFs exhibited promising properties, such as excellent mechanical strength, biocompatibility, and electrical conductivity. These results showed that the fabricated nanocomposites could be applied as the bone tissue engineering scaffold.


Assuntos
Osso e Ossos/citologia , Carbono/química , Compostos Ferrosos/química , Nanofibras/química , Engenharia Tecidual/métodos , Tecidos Suporte/química , Linhagem Celular , Proliferação de Células , Condutividade Elétrica , Humanos , Nanofibras/ultraestrutura
9.
Int J Mol Sci ; 22(14)2021 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-34299003

RESUMO

Here, we designed paper sheets coated with chitosan, bacterial cellulose (nanofibers), and ZnO with boosted antibacterial and mechanical activity. We investigated the compositions, with ZnO exhibiting two different sizes/shapes: (1) rods and (2) irregular sphere-like particles. The proposed processing of bacterial cellulose resulted in the formation of nanofibers. Antimicrobial behavior was tested using E. coli ATCC® 25922™ following the ASTM E2149-13a standard. The mechanical properties of the paper sheets were measured by comparing tearing resistance, tensile strength, and bursting strength according to the ISO 5270 standard. The results showed an increased antibacterial response (assigned to the combination of chitosan and ZnO, independent of its shape and size) and boosted mechanical properties. Therefore, the proposed composition is an interesting multifunctional mixture for coatings in food packaging applications.


Assuntos
Biopolímeros/química , Biopolímeros/farmacologia , Celulose/química , Quitosana/química , Nanocompostos/química , Embalagem de Produtos/métodos , Óxido de Zinco/química , Anti-Infecciosos , Celulose/ultraestrutura , Escherichia coli , Testes Mecânicos , Nanopartículas Metálicas/química , Nanopartículas Metálicas/ultraestrutura , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Nanocompostos/ultraestrutura , Nanofibras/química , Nanofibras/ultraestrutura , Propriedades de Superfície , Resistência à Tração , Difração de Raios X
10.
Int J Mol Sci ; 22(12)2021 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-34198611

RESUMO

Sensors and biosensors have found applications in many areas, e.g., in medicine and clinical diagnostics, or in environmental monitoring. To expand this field, nanotechnology has been employed in the construction of sensing platforms. Because of their properties, such as high surface area to volume ratio, nanofibers (NFs) have been studied and used to develop sensors with higher loading capacity, better sensitivity, and faster response time. They also allow to miniaturize designed platforms. One of the most commonly used techniques of the fabrication of NFs is electrospinning. Electrospun NFs can be used in different types of sensors and biosensors. This review presents recent studies concerning electrospun nanofiber-based electrochemical and optical sensing platforms for the detection of various medically and environmentally relevant compounds, including glucose, drugs, microorganisms, and toxic metal ions.


Assuntos
Técnicas Biossensoriais , Nanofibras/química , Nanotecnologia/métodos , Eletroquímica , Glucose/análise
11.
Int J Nanomedicine ; 16: 4471-4480, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34234437

RESUMO

Background: Postoperative tissue adhesion is a major concern for most surgeons and is a nearly unpreventable complication after abdominal or pelvic surgeries. This study explored the use of sandwich-structured antimicrobial agents, analgesics, and human epidermal growth factor (hEGF)-incorporated anti-adhesive poly(lactic-co-glycolic acid) nanofibrous membranes for surgical wounds. Materials and Methods: Electrospinning and co-axial electrospinning techniques were utilized in fabricating the membranes. After spinning, the properties of the prepared membranes were assessed. Additionally, high-performance liquid chromatography and enzyme-linked immunosorbent assays were utilized in assessing the in vitro and in vivo liberation profiles of the pharmaceuticals and the hEGF from the membranes. Results: The measured data suggest that the degradable anti-adhesive membranes discharged high levels of vancomycin/ceftazidime, ketorolac, and hEGF in vitro for more than 30, 24, and 27 days, respectively. The in vivo assessment in a rat laparotomy model indicated no adhesion in the peritoneal cavity at 14 days post-operation, demonstrating the anti-adhesive capability of the sandwich-structured nanofibrous membranes. The nanofibers also released effective levels of vancomycin, ceftazidime, and ketorolac for more than 28 days in vivo. Histological examination revealed no adverse effects. Conclusion: The outcomes of this study implied that the anti-adhesive nanofibers with sustained release of antimicrobial agents, analgesics, and growth factors might offer postoperative pain relief and infection control, as well as promote postoperative healing of surgical wounds.


Assuntos
Analgésicos/farmacologia , Anti-Infecciosos/farmacologia , Família de Proteínas EGF/metabolismo , Membranas Artificiais , Nanofibras/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Adesividade/efeitos dos fármacos , Analgésicos/química , Animais , Anti-Infecciosos/química , Humanos , Ratos , Ferida Cirúrgica/fisiopatologia , Cicatrização/efeitos dos fármacos
12.
Int J Nanomedicine ; 16: 4321-4332, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34211273

RESUMO

Background: As commonly bone defect is a disease of jaw that can seriously affect implant restoration, the bioactive scaffold can be used as potential systems to provide effective repair for bone defect. Purpose: A osteoinductive bone tissue engineering scaffold has been prepared in order to explore the effect of bioactive materials on bone tissue engineering. Methods: In this study, NELL-1 nanoparticles (Chi/NNP) and nano hydroxyapatite were incorporated in composite scaffolds by electrospinning and characterized using TEM, SEM, contact angle, tensile tests and in vitro drug release. In vitro biological activities such as MC3T3-E1 cell attachment, proliferation and osteogenic activity were studied. Results: With the addition of nHA and nanoparticles, the fiber diameter of PCL/BNPs group, PCL/NNPs group and PCL/nHA/NNPs group was significantly increased. Moreover, the hydrophilic hydroxyl group and amino group presented in nHA and nanoparticles had improved the hydrophilicity of the composite fibers. The composite electrospun containing Chi/NNPs can form a double protective barrier which can effectively prolong the release time of NELL-1 growth factor. In addition, the hydroxyapatite/NELL-1 nanoparticles electrospun fibers can promote attachment, proliferation, differentiation of MC3T3-E1 cells and good cytocompatibility, indicating better ability of inducing osteogenic differentiation. Conclusion: A multi-functional PCL/nHA/NNPs composite fiber with long-term bioactivity and osteoinductivity was successfully prepared by electrospinning. This potential composite could be used as scaffolds in bone tissue engineering application after in vivo studies.


Assuntos
Proteínas de Ligação ao Cálcio/farmacologia , Durapatita/química , Nanofibras/química , Osteogênese/efeitos dos fármacos , Engenharia Tecidual/métodos , Osso e Ossos , Proteínas de Ligação ao Cálcio/química , Proteínas de Ligação ao Cálcio/farmacocinética , Diferenciação Celular/efeitos dos fármacos , Quitosana/química , Liberação Controlada de Fármacos , Humanos , Microscopia Eletrônica de Varredura , Nanopartículas/química , Poliésteres/química , Soroalbumina Bovina/química , Tecidos Suporte
13.
Int J Biol Macromol ; 185: 77-86, 2021 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-34139244

RESUMO

Nanostructure provides a closer structural support approximation to native bone architecture for cells and further regulates cell's behavior, resulting in the formation of functional tissues. In this work, three engineering collagen templates with oriented fiber architectures were fabricated via electrospinning (Es), plastic compression and tensile (PCT), and dynamic shear stress (SS) methods. Under the observation of POM, SEM, AFM and TEM, the PCT-template and SS-template are packed with well-oriented nanofibers with the native collagen architecture of 67 nm D-periodicity, and the mechanical properties conferred to the templates are better than that of the Es-template. When mentioning the cell's behavior, MC3T3-E1 adhered to grow along the alignment of collagen fiber orientation when cultured on the PCT-template and SS-template. The SS-template with nano- and micro-ordered architecture guided cells to stretch their plasma along with the orientation of collagen fiber, produce more aligned Type I collagen fibers and promote significantly higher osteogenic differentiation of MC3T3-E1 than the PCT-template and Es-template. Overall, it is strongly argued the feasibility of hierarchical collagen fiber architectures for bone tissue regeneration.


Assuntos
Colágeno/química , Osteoblastos/citologia , Engenharia Tecidual/métodos , Células 3T3 , Animais , Diferenciação Celular , Proliferação de Células , Camundongos , Nanofibras/química , Osteogênese , Ratos , Estresse Mecânico , Tecidos Suporte
14.
AAPS PharmSciTech ; 22(5): 170, 2021 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-34085150

RESUMO

A novel nanofiber insert was prepared with a modified electrospinning method to enhance the ocular residence time of ofloxacin (OFX) and to provide a sustained release pattern by covering hydrophilic polymers, chitosan/polyvinyl alcohol (CS/PVA) nanofibers, with a hydrophobic polymer, Eudragit RL100 in layers, and by glutaraldehyde (GA) cross-linking of CS-PVA nanofibers for the treatment of infectious conjunctivitis. The morphology of the prepared nanofibers was studied using scanning electron microscopy (SEM). The average fiber diameter was found to be 123 ± 23 nm for the single electrospun nanofiber with no cross-linking (OFX-O). The single nanofibers, cross-linked for 10 h with GA (OFX-OG), had an average fiber diameter of 159 ± 30 nm. The amount of OFX released from the nanofibers was measured in vitro and in vivo using UV spectroscopy and microbial assay methods against Staphylococcus aureus, respectively. The antimicrobial efficiency of OFX formulated in cross-linked and non-cross-linked nanofibers was affirmed by observing the inhibition zones of Staphylococcus aureus and Escherichia coli. In vivo studies using the OFX nanofibrous inserts on a rabbit eye confirmed a sustained release pattern for up to 96 h. It was found that the cross-linking of the nanofibers by GA vapor could reduce the burst release of OFX from OFX-loaded CS/PVA in one layer and multi-layered nanofibers. In vivo results showed that the AUC0-96 for the nanofibers was 9-20-folds higher compared to the OFX solution. This study thus demonstrates the potential of the nanofiber technology is being utilized to sustained drug release in ocular drug delivery systems.


Assuntos
Resinas Acrílicas/química , Administração Oftálmica , Quitosana/química , Nanofibras/química , Ofloxacino/química , Álcool de Polivinil/química , Resinas Acrílicas/administração & dosagem , Resinas Acrílicas/farmacocinética , Animais , Antibacterianos/química , Química Farmacêutica/métodos , Quitosana/administração & dosagem , Quitosana/farmacocinética , Preparações de Ação Retardada/administração & dosagem , Preparações de Ação Retardada/química , Preparações de Ação Retardada/farmacocinética , Sistemas de Liberação de Medicamentos/métodos , Avaliação Pré-Clínica de Medicamentos/métodos , Escherichia coli/efeitos dos fármacos , Escherichia coli/fisiologia , Nanofibras/administração & dosagem , Ofloxacino/administração & dosagem , Ofloxacino/farmacocinética , Álcool de Polivinil/administração & dosagem , Álcool de Polivinil/farmacocinética , Coelhos , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/fisiologia
15.
Molecules ; 26(9)2021 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-34063713

RESUMO

Chitosan has many useful intrinsic properties (e.g., non-toxicity, antibacterial properties, and biodegradability) and can be processed into high-surface-area nanofiber constructs for a broad range of sustainable research and commercial applications. These nanofibers can be further functionalized with bioactive agents. In the food industry, for example, edible films can be formed from chitosan-based composite fibers filled with nanoparticles, exhibiting excellent antioxidant and antimicrobial properties for a variety of products. Processing 'pure' chitosan into nanofibers can be challenging due to its cationic nature and high crystallinity; therefore, chitosan is often modified or blended with other materials to improve its processability and tailor its performance to specific needs. Chitosan can be blended with a variety of natural and synthetic polymers and processed into fibers while maintaining many of its intrinsic properties that are important for textile, cosmeceutical, and biomedical applications. The abundance of amine groups in the chemical structure of chitosan allows for facile modification (e.g., into soluble derivatives) and the binding of negatively charged domains. In particular, high-surface-area chitosan nanofibers are effective in binding negatively charged biomolecules. Recent developments of chitosan-based nanofibers with biological activities for various applications in biomedical, food packaging, and textiles are discussed herein.


Assuntos
Quitosana/química , Cosmecêuticos/química , Embalagem de Alimentos , Têxteis , Aminas/química , Animais , Antibacterianos/química , Anti-Infecciosos/química , Antioxidantes/química , Cristalização , Filmes Comestíveis , Humanos , Nanofibras/química , Nanopartículas/química , Polímeros , Regeneração , Pele/patologia , Pele Artificial , Solubilidade , Engenharia Tecidual , Cicatrização
16.
Molecules ; 26(9)2021 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-34066875

RESUMO

The main core of wound treatment is cell growth and anti-infection. To accelerate the proliferation of fibroblasts in the wound and prevent wound infections, various strategies have been tried. It remains a challenge to obtain good cell proliferation and antibacterial effects. Here, human hair kerateine (HHK)/poly(ethylene oxide) (PEO)/poly(vinyl alcohol) (PVA) nanofibers were prepared using cysteine-rich HHK, and then, silver nanoparticles (AgNPs) were in situ anchored in the sulfur-containing amino acid residues of HHK. After the ultrasonic degradation test, HHK/PEO/PVA nanofibrous mats treated with 0.005-M silver nitrate were selected due to their relatively complete structures. It was observed by TEM-EDS that the sulfur-containing amino acids in HHK were the main anchor points of AgNPs. The results of FTIR, XRD and the thermal analysis suggested that the hydrogen bonds between PEO and PVA were broken by HHK and, further, by AgNPs. AgNPs could act as a catalyst to promote the thermal degradation reaction of PVA, PEO and HHK, which was beneficial for silver recycling and medical waste treatment. The antibacterial properties of AgNP-HHK/PEO/PVA nanofibers were examined by the disk diffusion method, and it was observed that they had potential antibacterial capability against Gram-positive bacteria, Gram-negative bacteria and fungi. In addition, HHK in the nanofibrous mats significantly improved the cell proliferation of NIH3T3 cells. These results illustrated that the AgNP-HHK/PEO/PVA nanofibrous mats exhibited excellent antibacterial activity and the ability to promote the proliferation of fibroblasts, reaching our target applications.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Proliferação de Células/efeitos dos fármacos , Queratinas Específicas do Cabelo/química , Nanopartículas Metálicas/química , Nanofibras/química , Polietilenoglicóis/química , Álcool de Polivinil/química , Prata/química , Animais , Candida albicans/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Cabelo/química , Humanos , Ligação de Hidrogênio , Camundongos , Testes de Sensibilidade Microbiana , Células NIH 3T3 , Nitrato de Prata/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Cicatrização/efeitos dos fármacos
17.
Int J Biol Macromol ; 184: 648-665, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-34102239

RESUMO

Nanofibers have a particular benefit when delivering a spectrum of therapeutic drugs for diverse biomedical applications. Nanofibers are easily fabricated from cellulose acetate, chitosan, polycaprolactone, and other polymers with regulated morphology and release profiles due to nanotechnology's recent advancement. This review will provide the latest approaches to the fabrication of electrospun nanofibers containing herbal extracts, antimicrobial peptides, and antibiotics for wound-healing potential. Besides, synthesis and evaluation of nanofibrous mats, including conducting polymer and evaluate their possibility for wound healing. In addition, nanofibers are loaded with some drugs for skin cancer treatment and contain growth factors for tissue regeneration. Also, the current two-dimensional nanofibers limitations and the various techniques for convert two-dimensional to three-dimension nanofibers to avoid these drawbacks. Moreover, the future direction in improving the three-dimensional structure and functionality has been including.


Assuntos
Nanofibras/química , Polissacarídeos/química , Cicatrização/efeitos dos fármacos , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Sistemas de Liberação de Medicamentos , Desenho de Fármacos , Humanos , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Proteínas Citotóxicas Formadoras de Poros/química , Proteínas Citotóxicas Formadoras de Poros/farmacologia
18.
ACS Appl Mater Interfaces ; 13(25): 29293-29302, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34128651

RESUMO

Biological recognition sites are very useful for biomedical purposes and, more specifically, for polymeric scaffolds. However, synthetic polymers are not capable of providing specific biological recognition sites. To solve this inconvenience, functionalization of biological moieties is typically performed, oftentimes via peptide binding. In this sense, the main task is capturing the biological complexity of a protein. This study proposes a possible alternative solution to this challenge. Our approach is based on the combination of molecular imprinting (MI) and electrospinning processes. We propose here an alternative MI approach with polymeric structures, instead of using cross-linkers and monomers as conventionally performed. Different PCL-protein scaffolds were produced via electrospinning before performing MI. Gelatin, collagen, and elastin were used as proteins. Results evidenced that the MI process conducted with PCL electrospun membranes was carried out with ionic interactions between the desired molecules and the recognition sites formed. In addition, it has been proved that MI was more efficient when using gelatin as a template. This approach opens a new stage in the development of recognition sites in scaffolds obtained with synthetic polymers and their application for biomedical purposes.


Assuntos
Técnicas Eletroquímicas/métodos , Impressão Molecular/métodos , Poliésteres/química , Proteínas/química , Gelatina/química , Nanofibras/química
19.
Int J Nanomedicine ; 16: 3661-3678, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34093011

RESUMO

Introduction: Brain ischemia is a common neurological disorder worldwide that activates a cascade of pathophysiological events involving decreases in oxygen and glucose levels. Despite substantial efforts to explore its pathogenesis, the management of ischemic neuronal injury remains an enormous challenge. Accumulating evidence suggests that VEGF modified nanofiber (NF) materials and the fatty-acid amide hydrolase (FAAH) inhibitor URB597 exert an influence on alleviating ischemic brain damage. We aimed to further investigate their effects on primary hippocampal neurons, as well as the underlying mechanisms following oxygen-glucose deprivation (OGD). Methods: Different layers of VEGF-A loaded polycaprolactone (PCL) nanofibrous membranes were first synthesized by using layer-by-layer (LBL) self-assembly of electrospinning methods. The physicochemical and biological properties of VEGF-A NF membranes, and their morphology, hydrophilicity, and controlled-release of VEGF-A were then estimated. Furthermore, the effects of VEGF-A NF and URB597 on OGD-induced mitochondrial oxidative stress, inflammatory responses, neuronal apoptosis, and endocannabinoid signaling components were assessed. Results: The VEGF-A NF membrane and URB597 can not only promote hippocampal neuron adhesion and viability following OGD but also exhibited antioxidant/anti-inflammatory and mitochondrial membrane potential protection. The VEGF-A NF membrane and URB597 also inhibited OGD-induced cellular apoptosis through activating CB1R signaling. These results indicate that VEGF-A could be controlled-released by LBL self-assembled NF membranes. Discussion: The VEGF-A NF membrane and URB597 displayed positive synergistic neuroprotective effects through the inhibition of mitochondrial oxidative stress and activation of CB1R/PI3K/AKT/BDNF signaling, suggesting that a VEGF-A loaded NF membrane and the FAAH inhibitor URB597 could be of therapeutic value in ischemic cerebrovascular diseases.


Assuntos
Benzamidas/farmacologia , Carbamatos/farmacologia , Nanofibras/química , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Fator A de Crescimento do Endotélio Vascular/farmacologia , Amidoidrolases/antagonistas & inibidores , Amidoidrolases/metabolismo , Animais , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Isquemia Encefálica/tratamento farmacológico , Isquemia Encefálica/metabolismo , Isquemia Encefálica/patologia , Células Cultivadas , Endocanabinoides/metabolismo , Glucose/metabolismo , Hipocampo/efeitos dos fármacos , Hipocampo/patologia , Membranas Artificiais , Neurônios/metabolismo , Neurônios/patologia , Oxigênio/metabolismo , Ratos Sprague-Dawley , Fator A de Crescimento do Endotélio Vascular/química
20.
Nat Commun ; 12(1): 3248, 2021 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-34059677

RESUMO

Water scarcity is rapidly spreading across the planet, threatening the population across the five continents and calling for global sustainable solutions. Water reclamation is the most ecological approach for supplying clean drinking water. However, current water purification technologies are seldom sustainable, due to high-energy consumption and negative environmental footprint. Here, we review the cutting-edge technologies based on protein nanofibrils as water purification agents and we highlight the benefits of this green, efficient and affordable solution to alleviate the global water crisis. We discuss the different protein nanofibrils agents available and analyze them in terms of performance, range of applicability and sustainability. We underline the unique opportunity of designing protein nanofibrils for efficient water purification starting from food waste, as well as cattle, agricultural or dairy industry byproducts, allowing simultaneous environmental, economic and social benefits and we present a case analysis, including a detailed life cycle assessment, to establish their sustainable footprint against other common natural-based adsorbents, anticipating a bright future for this water purification approach.


Assuntos
Conservação dos Recursos Hídricos , Nanofibras/química , Proteínas/química , Desenvolvimento Sustentável , Purificação da Água/métodos , Adsorção , Indústria de Laticínios , Interações Hidrofóbicas e Hidrofílicas , Eliminação de Resíduos/métodos , Poluentes da Água/química , Abastecimento de Água
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