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1.
Molecules ; 28(2)2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36677926

RESUMO

Carbon microcoils (CMCs) were formed on stainless steel substrates using C2H2 + SF6 gas flows in a thermal chemical vapor deposition (CVD) system. The manipulation of the SF6 gas flow rate and the SF6 gas flow injection time was carried out to obtain controllable CMC geometries. The change in CMC geometry, especially CMC diameter as a function of SF6 gas flow injection time, was remarkable. In addition, the incorporation of H2 gas into the C2H2 + SF6 gas flow system with cyclic SF6 gas flow caused the formation of the hybrid of carbon nanofibers-carbon microcoils (CNFs-CMCs). The hybrid of CNFs-CMCs was composed of numerous small-sized CNFs, which formed on the CMCs surfaces. The electromagnetic wave shielding effectiveness (SE) of the heating film, made by the hybrids of CNFs-CMCs incorporated carbon paste film, was investigated across operating frequencies in the 1.5-40 GHz range. It was compared to heating films made from commercial carbon paste or the controllable CMCs incorporated carbon paste. Although the electrical conductivity of the native commercial carbon paste was lowered by both the incorporation of the CMCs and the hybrids of CNFs-CMCs, the total SE values of the manufactured heating film increased following the incorporation of these materials. Considering the thickness of the heating film, the presently measured values rank highly among the previously reported total SE values. This dramatic improvement in the total SE values was mainly ascribed to the intrinsic characteristics of CMC and/or the hybrid of CNFs-CMCs contributing to the absorption shielding route of electromagnetic waves.


Assuntos
Calefação , Nanofibras , Carbono , Condutividade Elétrica , Gases
2.
Biofabrication ; 15(2)2023 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-36608336

RESUMO

Tendon injuries are common debilitating musculoskeletal diseases with high treatment expenditure in sports medicine. The development of tendon-biomimetic scaffolds may be promising for improving the unsatisfactory clinical outcomes of traditional therapies. In this study, we combined an advanced electrospun nanofiber yarn-generating technique with a traditional textile manufacturing strategy to fabricate innovative nano-micro fibrous woven scaffolds with tendon-like anisotropic structure and high-strength mechanical properties for the treatment of large-size tendon injury. Electrospun nanofiber yarns made from pure poly L-lactic acid (PLLA) or silk fibroin (SF)/PLLA blend were fabricated, and their mechanical properties matched and even exceeded those of commercial PLLA microfiber yarns. The PLLA or SF/PLLA nanofiber yarns were then employed as weft yarns interlaced with commercial PLLA microfiber yarns as warp yarns to generate two new types of nanofibrous scaffolds (nmPLLA and nmSF/PLLA) with a plain-weaving structure. Woven scaffolds made from pure PLLA microfiber yarns (both weft and warp directions) (mmPLLA) were used as controls.In vitroexperiments showed that the nmSF/PLLA woven scaffold with aligned fibrous topography significantly promoted cell adhesion, elongation, proliferation, and phenotypic maintenance of tenocytes compared with mmPLLA and nmPLLA woven scaffolds. Moreover, the nmSF/PLLA woven scaffold exhibited the strongest immunoregulatory functions and effectively modulated macrophages towards the M2 phenotype.In vivoexperiments revealed that the nmSF/PLLA woven scaffold notably facilitated Achilles tendon regeneration with improved structure by macroscopic, histological, and ultrastructural observations six months after surgery, compared with the other two groups. More importantly, the regenerated tissue in the nmSF/PLLA group had excellent biomechanical properties comparable to those of the native tendon. Overall, our study provides an innovative biological-free strategy with ready-to-use features, which presents great potential for clinical translation for damaged tendon repair.


Assuntos
Fibroínas , Nanofibras , Tecidos Suporte/química , Engenharia Tecidual/métodos , Poliésteres/química , Tendões , Nanofibras/química , Fibroínas/química , Regeneração
3.
Sci Rep ; 13(1): 51, 2023 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-36593253

RESUMO

The bacterial nanocellulose has been used in a wide range of biomedical applications including carriers for drug delivery, blood vessels, artificial skin and wound dressing. The total of ten morphologically different bacterial strains were screened for their potential to produce bacterial nanocellulose (BNC). Among these isolates, Bacillus sp. strain SEE-3 exhibited potent ability to produce the bacterial nanocellulose. The crystallinity, particle size and morphology of the purified biosynthesized nanocellulose were characterized. The cellulose nanofibers possess a negatively charged surface of - 14.7 mV. The SEM images of the bacterial nanocellulose confirms the formation of fiber-shaped particles with diameters of 20.12‒47.36 nm. The TEM images show needle-shaped particles with diameters of 30‒40 nm and lengths of 560‒1400 nm. X-ray diffraction show that the obtained bacterial nanocellulose has crystallinity degree value of 79.58%. FTIR spectra revealed the characteristic bands of the cellulose crystalline structure. The thermogravimetric analysis revealed high thermal stability. Optimization of the bacterial nanocellulose production was achieved using Plackett-Burman and face centered central composite designs. Using the desirability function, the optimum conditions for maximum bacterial nanocellulose production was determined theoretically and verified experimentally. Maximum BNC production (20.31 g/L) by Bacillus sp. strain SEE-3 was obtained using medium volume; 100 mL/250 mL conical flask, inoculum size; 5%, v/v, citric acid; 1.5 g/L, yeast extract; 5 g/L, temperature; 37 °C, Na2HPO4; 3 g/L, an initial pH level of 5, Cantaloupe juice concentration of 81.27 percent and peptone 11.22 g/L.


Assuntos
Bacillus , Cucumis melo , Nanofibras , Bactérias/química , Celulose/química , Meios de Cultura/química
4.
Dent Mater ; 39(1): 132-139, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36604256

RESUMO

OBJECTIVES: The aim of the present study was to prepare resorbable polylactide fibers for periodontitis treatment using coaxial electrospinning to optimize the release of metronidazole (MNA) by reducing the initial burst effect. METHODS: Poly(L-lactide-co-D,L-lactide) (PLA) fibers mats with different distributions of metronidazole (MNA) were manufactured by coaxial electrospinning (COAX). By COAX spinning the central core of the fiber was enriched with 40% MNA (m/m), while the sheath of the fiber consisted of PLA only (test group). In contrast, fibers of the control group were prepared by conventional electrospinning with the same amount of MNA but with a homogenous drug distribution (HDD - homogenously distributed drug). The release of MNA was determined by analyzing aliquots from the fiber mats using UV-VIS spectroscopy. Agar diffusion tests were carried out to determine the antibacterial effect on periodontopathogenic bacteria. Biocompatibility was tested in direct contact to human gingival fibroblasts (HGF) for two days. RESULTS: The COAX mats showed a retarded drug release compared to the conventional HDD fibers. After 24 h, 64% of total MNA was released cumulatively from the COAX fibers while 90% of the MNA was released from the HDD fibers (controls). The antibacterial effect of COAX fibers was significantly higher after 24 h compared to the HDD fibers. Cell cultivation revealed significant higher numbers of vital cells among the COAX mats. SIGNIFICANCE: COAX fibers showed improved sustained MNA release compared to conventional fibers and can be seen as potential drug delivery systems in local periodontitis treatment.


Assuntos
Nanofibras , Periodontite , Humanos , Metronidazol/farmacologia , Nanofibras/química , Sistemas de Liberação de Medicamentos , Antibacterianos/farmacologia , Antibacterianos/química , Poliésteres/química , Periodontite/tratamento farmacológico , Liberação Controlada de Fármacos
5.
Carbohydr Polym ; 302: 120394, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36604072

RESUMO

The development of double encryption system enables information to switch reversibly between "False" and "True", which helps to ensure information security in the transmission process. Herein, a biomimetic cellulose nanofibre-based double information encryption sensor (CNF-DIES) with an excellent pH response and fluorescence colour-switching performance was prepared with fluorescein isothiocyanate and protoporphyrin IX modified acetylated cellulose nanofibres (ACNF) as the pH response switch and background, respectively. Interestingly, with the addition of cellulose, CNF-DIES can be regarded as both a dye and an ink binder, which can realize direct writing function. The fluorescein grafted to ACNF guaranteed the stability of writing and avoided the "coffee ring" phenomenon. The handwriting written by CNF-DIES processes excellent light/pH double encryption performance. Besides, the film prepared by CNF-DIES can realize high resolution fingerprint imaging. This work demonstrated a strategy for pH-responsive colour-tunable materials for sensors and double information encryption.


Assuntos
Celulose , Nanofibras , Biomimética , Diagnóstico por Imagem , Excipientes , Fluoresceína
6.
Carbohydr Polym ; 302: 120421, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36604083

RESUMO

Cellulose is regarded as the most abundant biomass, and nanocellulose derived from it has numerous applications in environmentally friendly materials. However, owing to the abundant hydroxyl groups on surface, nanocellulose is prone to agglomeration when transported, stored, or made into materials, which destroys material performance and limits its use. In this study, a feasible method was presented for regulating the hydrogen bonding strength between cellulose nanofibers (CNFs) by adding a minute quantity of rare earth ions Y3+ during cellulose nanofibrillation. It was found that the strength of hydrogen bonding between CNFs can be regulated by controlling the quantity of Y3+ in the system. The dispersibility and stability of CNFs, as well as the mechanical properties of CNFs films and CNFs-reinforced papers can be improved by 43.07 % and by 64.05 % after adding only 0.05 or 0.075 wt% Y3+. The possible mechanism of CNFs hydrogen bonding network reconstruction was proposed.


Assuntos
Celulose , Nanofibras , Ligação de Hidrogênio , Íons
7.
Carbohydr Polym ; 302: 120431, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36604092

RESUMO

Chitosan based nanofibers are emerging biomaterials with a plethora of applications, especially in medicine and healthcare. Herein, binary quaternized chitosan/chitosan fibers are reported for the first time. Their preparation strategy consisted in the electrospinning of ternary chitosan/quaternized chitosan/poly(ethylene oxide) solutions followed by the selective removal of poly(ethylene oxide). Their morphology and performances were systematically investigated and discussed in detail. It was found that the fibers had reversible water vapor adsorption/desorption and showed swelling degrees similar to commercial wound dressings. They presented good mechanical properties and the content of quaternized chitosan modulated their bioadhesion, mucoadhesion and biodegradation rate and conferred them strong antimicrobial activity. Tests on normal human fibroblasts confirmed their safely use in contact with tissues and the biocompatibility investigation on rats showed no harmful effect when subcutaneous implanted. All these proved the binary quaternized chitosan/chitosan fibers as bioactive materials suitable for tissue regeneration, wound healing and drug delivery systems.


Assuntos
Quitosana , Nanofibras , Humanos , Ratos , Animais , Engenharia Tecidual , Medicina Regenerativa , Óxido de Etileno , Antibacterianos/farmacologia
8.
Sci Rep ; 13(1): 919, 2023 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-36650249

RESUMO

Considering the great potential of egg yolk oil (EYO) in management of burn wounds and superb biological properties of polycaprolactone (PCL) and polyethylene glycol (PEG), hereby, a PCL-PEG-EYO scaffold was developed by electrospinning method for burn healing. The physico-chemical characterizations were performed using SEM, FTIR and contact angle tests. The biological properties of the fabricated scaffolds were evaluated by antibacterial test, in vitro cell culturing, MTT assay and in vivo experiments. The SEM images of PCL-PEG-EYO nanofibers demonstrated a uniform bead-free morphology with 191 ± 61 nm diameter. The fabricated scaffold revealed hydrophilicity with the water contact angel of 77°. No cytotoxicity was observed up to 7 days after cell culturing onto the PCL-PEG-EYO nanofibrous surface. The presence of EYO in the PCL-PEG-EYO scaffold meaningfully improved the cell viability, proliferation and attachment compared to PCL-PEG scaffold. Moreover, the PCL-PEG-EYO scaffolds demonstrated antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa bacteria strain. Finally, a statistically significant enhancement in wound closure, re-epithelialization, angiogenesis and collagen synthesis was observed at the end of 21-day treatment period using PCL-PEG-EYO nanofibrous scaffold. Overall, the PCL-PEG-EYO nanofibrous scaffolds demonstrated a great potential in management of full thickness burn wounds in vivo.


Assuntos
Queimaduras , Nanofibras , Humanos , Tecidos Suporte/química , Engenharia Tecidual/métodos , Nanofibras/química , Polietilenoglicóis/química , Gema de Ovo , Poliésteres/química , Antibacterianos/farmacologia , Queimaduras/tratamento farmacológico , Aceleração
9.
Biomater Adv ; 145: 213275, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36608438

RESUMO

The development of new cancer treatment options, such as multifunctional devices, allows for a more personalized treatment, avoiding the known severe side effects of conventional options. In this context, on-demand drug delivery systems can actively control the rate of drug release offering a precise control of treatment. Magnetically and thermally controlled drug delivery systems have been explored as on-demand devices to treat chronic diseases and cancer tumors. In the present work, dual-stimuli responsive systems were developed by incorporating Fe3O4 magnetic nanoparticles (NPs) and poly(N-isopropylacrylamide) (PNIPAAm) microgels into electrospun polymeric fibers for application in cancer treatment. First, Fe3O4 NPs with an average diameter of 8 nm were synthesized by chemical precipitation technique and stabilized with dimercaptosuccinic acid (DMSA) or oleic acid (OA). PNIPAAm microgels were synthesized by surfactant-free emulsion polymerization (SFEP). Poly(vinyl alcohol) (PVA) was used as a fiber template originating fibers with an average diameter of 179 ± 14 nm. Stress tests of the membranes showed that incorporating both microgels and Fe3O4 NPs in electrospun fibers increases their Young's modulus. Swelling assays indicate that PVA membranes have a swelling ratio of around 3.4 (g/g) and that the presence of microgels does not affect its swelling ability. However, with the incorporation of Fe3O4 NPs, the swelling ratio of the membranes decreases. Magnetic hyperthermia assays show that a higher concentration of NPs leads to a higher heating ability. The composite membrane with the most promising results is the one incorporated with DMSA-coated NPs, since it shows the highest temperature variation, 5.1 °C. To assess the membranes biocompatibility and ability to promote cell proliferation, indirect and direct contact cell viability assays were performed, as well as cell adhesion assays. Following an extract method viability assay, all membrane designs did not reveal cytotoxic effects on dermal fibroblasts and melanoma cancer cells, after 48 h exposure and support long-term viability. The present work demonstrates the potential of dual-stimuli composite membranes for magnetic hyperthermia and may in the future be used as an alternative cancer treatment particularly in anatomically reachable solid tumors.


Assuntos
Hipertermia Induzida , Microgéis , Nanofibras , Neoplasias , Álcool de Polivinil , Fenômenos Magnéticos
10.
Carbohydr Polym ; 303: 120429, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36657829

RESUMO

Oromucosal administration is an attractive non-invasive route. However, drug absorption is challenged by salivary flow and the mucosa being a significant permeability barrier. The aim of this study was to design and investigate a multi-layered nanofiber-on-foam-on-film (NFF) drug delivery system with unique properties and based on polysaccharides combined as i) mucoadhesive chitosan-based nanofibers, ii) a peptide loaded hydroxypropyl methylcellulose foam, and iii) a saliva-repelling backing film based on ethylcellulose. NFF displays optimal mechanical properties shown by dynamic mechanical analysis, and biocompatibility demonstrated after exposure to a TR146 cell monolayer. Chitosan-based nanofibers provided the NFF with improved mucoadhesion compared to that of the foam alone. After 1 h, >80 % of the peptide desmopressin was released from the NFF. Ex vivo permeation studies across porcine buccal mucosa indicated that NFF improved the permeation of desmopressin compared to a commercial freeze-dried tablet. The findings demonstrate the potential of the NFF as a biocompatible drug delivery system.


Assuntos
Quitosana , Nanofibras , Animais , Suínos , Quitosana/química , Desamino Arginina Vasopressina , Celulose/química , Sistemas de Liberação de Medicamentos , Mucosa Bucal , Peptídeos , Administração Bucal
11.
Mikrochim Acta ; 190(2): 64, 2023 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-36690871

RESUMO

The fabrication of SERS substrate by gold nanoparticle-decorated polyvinyl alcohol electrospun nanofibers which has been used to detect trace sensing of two widely used poultry antibiotics doxycycline hydrochloride and enrofloxacin is demonstrated. The performance of the backscattered Raman signals from the proposed SERS substrate has been initially evaluated with two standard Raman active compounds namely malachite green and rhodamine-6G. The limit of detection of the proposed substrate is estimated to be 7.32 nM. Following this, the usability of the proposed SERS substrate has been demonstrated through the detection of the aforementioned antibiotics in chicken meat samples. The presence of antibiotics in chicken meat sample has been validated with the standard analytical tool of liquid chromatography-mass spectrometry and the results were compared with the proposed sensing technique. Further, principal component analysis has been performed to classify the antibiotics that are present in the field-collected meat samples.


Assuntos
Nanopartículas Metálicas , Nanofibras , Animais , Nanopartículas Metálicas/química , Ouro/química , Galinhas , Antibacterianos , Nanofibras/química , Análise Espectral Raman/métodos , Carne
12.
J Pharm Biomed Anal ; 225: 115223, 2023 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-36623427

RESUMO

Nanofibers (NFs) can be encapsulated with cyclodextrins (CDs) based host-guest complexes (HCs) in order to enable many biological applications. Here, benzocaine (BNZ) forms HCs with ß-cyclodextrin (ß-CD) that are co-precipitated and further added to polyacrylonitrile (PAN) solution for making BNZ:ß-CD-HCs/PAN NFs material with the aid of electrospinning technique. The marginal increase in absorbance and fluorescence intensity along with the shift in spectral maxima of BNZ in the presence of ß-CD suggested the host-guest interaction between BNZ and ß-CD. NFs showed a uniform and clean morphology in SEM images and interestingly, the ICs revealed that significantly thinner in terms of average fiber diameter (AFD) than those of free BNZ on PAN medium. BNZ molecule is completely included in the PAN surface as the result of NFs and thus, the original sharp peaks for the BNZ have vanished and the peaks are much broader for the BNZ and BNZ:ß-CD-HCs. BNZ is also found to be a good candidate for anti-inflammatory, anti-oxidant, and anti-diabetic. The results showed an improved activity when it is in the form of HCs on a PAN medium. Making HCs of drugs could be significant in biological applications.


Assuntos
Ciclodextrinas , Nanofibras , Benzocaína , Resinas Acrílicas , Antioxidantes
13.
Nat Commun ; 14(1): 359, 2023 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-36690639

RESUMO

Ion channels transduce external stimuli into ion-transport-mediated signaling, which has received considerable attention in diverse fields such as sensors, energy harvesting devices, and desalination membrane. In this work, we present a photosensitive ion channel based on plasmonic gold nanostars (AuNSs) and cellulose nanofibers (CNFs) embedded in layered MXene nanosheets. The MXene/AuNS/CNF (MAC) membrane provides subnanometer-sized ionic pathways for light-sensitive cationic flow. When the MAC nanochannel is exposed to NIR light, a photothermal gradient is formed, which induces directional photothermo-osmotic flow of nanoconfined electrolyte against the thermal gradient and produces a net ionic current. MAC membrane exhibits enhanced photothermal current compared with pristine MXene, which is attributed to the combined photothermal effects of plasmonic AuNSs and MXene and the widened interspacing of the MAC composite via the hydrophilic nanofibrils. The MAC composite membranes are envisioned to be applied in flexible ionic channels with ionogels and light-controlled ionic circuits.


Assuntos
Celulose , Nanofibras , Ouro , Cátions
14.
Biomolecules ; 13(1)2023 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-36671570

RESUMO

Herbal medicine has a long history of medical efficacy with low toxicity, side effects and good biocompatibility. However, the bioavailability of the extract of raw herbs and bioactive compounds is poor because of their low water solubility. In order to overcome the solubility issues, electrospinning technology can offer a delivery alternative to resolve them. The electrospun fibers have the advantages of high specific surface area, high porosity, excellent mechanical strength and flexible structures. At the same time, various natural and synthetic polymer-bound fibers can mimic extracellular matrix applications in different medical fields. In this paper, the development of electrospinning technology and polymers used for incorporating herbal medicine into electrospun nanofibers are reviewed. Finally, the recent progress of the applications of these herbal medicine nanofibers in biomedical (drug delivery, wound dressing, tissue engineering) and food fields along with their future prospects is discussed.


Assuntos
Nanofibras , Nanofibras/química , Engenharia Tecidual , Preparações Farmacêuticas , Polímeros/química , Extratos Vegetais
15.
Artigo em Inglês | MEDLINE | ID: mdl-36674061

RESUMO

Aerosol particles, such as the widespread COVID-19 recently, have posed a great threat to humans. Combat experience has proven that masks can protect against viruses; however, the epidemic in recent years has caused serious environmental pollution from plastic medical supplies, especially masks. Degradable filters are promising candidates to alleviate this problem. Degradable nanofiber filters, which are developed by the electrospinning technique, can achieve superior filtration performance. This review focuses on the basic introduction to air filtration, the general aspects of face masks, and nanofibers. Furthermore, the progress of the state of art degradable electrospun nanofiber filters have been summarized, such as silk fibroin (SF), polylactic acid (PLA), chitosan, cellulose, and zein. Finally, the challenges and future development are highlighted.


Assuntos
COVID-19 , Nanofibras , Humanos , Máscaras , COVID-19/prevenção & controle , Aerossóis e Gotículas Respiratórios , Filtração/métodos
16.
Int J Mol Sci ; 24(2)2023 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-36674734

RESUMO

Biomaterial-based nanofibrous scaffolds are the most effective alternative to bone transplantation therapy. Here, two recombinant minor ampullate spidroins (spider silk proteins), R1SR2 and NR1SR2C, were blended with Poly(lactic-co-glycolic) Acid (PLGA), respectively, to generate nanofiber scaffolds by electrospinning. The N-terminal (N), C-terminal (C), repeating (R1 and R2) and spacer (S) modules were all derived from the minor ampullate spidroins (MiSp). The physical properties and structures of the blended scaffolds were measured by scanning electron microscopy (SEM), water contact angle measurement, Fourier transform infrared spectroscopy (FTIR), Differential scanning calorimetry (DSC), and Tensile mechanical testing. The results showed that blending of MiSp (R1SR2 and NR1SR2C) reduced the diameter of nanofibers, increased the porosity and glass transition temperatures of nanofibrous scaffolds, and effectively improved the hydrophilicity and ultimate strain of scaffolds. It is worth noting that the above changes were more significant in the presence of the N- and C-termini of MiSp. In cell culture assays, human bone mesenchymal stem cells (HBMSCs) grown on NR1SR2C/PLGA (20/80) scaffolds displayed markedly enhanced proliferative and adhesive abilities compared with counterparts grown on pure PLGA scaffolds. Jointly, these findings indicated recombinant MiSp/PLGA, particularly NR1SR2C/PLGA (20/80) blend nanofibrous scaffolds, is promising for bone tissue engineering.


Assuntos
Fibroínas , Nanofibras , Humanos , Engenharia Tecidual/métodos , Nanofibras/química , Tecidos Suporte/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Ácido Poliglicólico/química , Fibroínas/química , Glicóis , Ácido Láctico/química , Proliferação de Células , Proteínas dos Microfilamentos , Fosfoproteínas , Proteínas de Ciclo Celular
17.
Int J Mol Sci ; 24(2)2023 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-36675021

RESUMO

Electrospun systems are becoming promising devices usable for topical treatments. They are eligible to deliver different therapies, from anti-inflammatory to antitumoral. In the current research, polycaprolactone electrospun membranes loaded with synthetic and commercial antitumoral active substances were produced, underlining how the matrix-filler affinity is a crucial parameter for designing drug delivery devices. Nanofibrous membranes loaded with different percentages of Dacarbazine (the drug of choice for melanoma) and a synthetic derivative of Dacarbazine were produced and compared to membranes loaded with AuM1, a highly active Au-complex with low affinity to the matrix. AFM morphologies showed that the surface profile of nanofibers loaded with affine substances is similar to one of the unloaded systems, thanks to the nature of the matrix-filler interaction. FTIR analyses proved the efficacy of the interaction between the amidic group of the Dacarbazine and the polycaprolactone. In AuM1-loaded membranes, because of the weak matrix-filler interaction, the complex is mainly aggregated in nanometric domains on the nanofiber surface, which manifests a nanometric roughness. Consequently, the release profiles follow a Fickian behavior for the Dacarbazine-based systems, whereas a two-step with a highly prominent burst effect was observed for AuM1 systems. The performed antitumoral tests evidence the high-cytotoxic activity of the electrospun systems against melanoma cell lines, proving that the synthetic substances are more active than the commercial dacarbazine.


Assuntos
Melanoma , Nanofibras , Humanos , Preparações Farmacêuticas , Sistemas de Liberação de Medicamentos , Anti-Inflamatórios , Excipientes , Dacarbazina/farmacologia , Melanoma/tratamento farmacológico , Liberação Controlada de Fármacos
18.
Biofabrication ; 15(2)2023 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-36595260

RESUMO

Spray nebulization is an elegant, but relatively unstudied, technique for scaffold production. Herein we fabricated mesh scaffolds of polycaprolactone (PCL) nanofibers via spray nebulization of 8% PCL in dichloromethane (DCM) using a 55.2 kPa compressed air stream and 17 ml h-1polymer solution flow rate. Using a refined protocol, we tested the hypothesis that spray nebulization would simultaneously generate nanofibers and eliminate solvent, yielding a benign environment at the point of fiber deposition that enabled the direct deposition of nanofibers onto cell monolayers. Nanofibers were collected onto a rotating plate 20 cm from the spray nozzle, but could be collected onto any static or moving surface. Scaffolds exhibited a mean nanofiber diameter of 910 ± 190 nm, ultimate tensile strength of 2.1 ± 0.3 MPa, elastic modulus of 3.3 ± 0.4 MPa, and failure strain of 62 ± 6%.In vitro, scaffolds supported growth of human keratinocyte cell epithelial-like layers, consistent with potential utility as a dermal scaffold. Fourier-transform infrared spectroscopy demonstrated that DCM had vaporized and was undetectable in scaffolds immediately following production. Exploiting the rapid elimination of DCM during fiber production, we demonstrated that nanofibers could be directly deposited on to cell monolayers, without compromising cell viability. This is the first description of spray nebulization generating nanofibers using PCL in DCM. Using this method, it is possible to rapidly produce nanofiber scaffolds, without need for high temperatures or voltages, yielding a method that could potentially be used to deposit nanofibers onto cell cultures or wound sites.


Assuntos
Nanofibras , Humanos , Nanofibras/química , Tecidos Suporte/química , Poliésteres/química , Polímeros , Engenharia Tecidual/métodos
19.
Nanotheranostics ; 7(1): 61-69, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36593799

RESUMO

Articular cartilage has a low self-repair capacity due to the lack of vessels and nerves. In recent times, nanofiber scaffolds have been widely used for this purpose. The optimum nanofiber scaffold should stimulate new tissue's growth and mimic the articular cartilage nature. Furthermore, the characteristics of the scaffold should match those of the cellular matrix components of the native tissue to best merge with the target tissue. Therefore, selective modification of prefabricated scaffolds based on the structure of the repaired tissues is commonly conducted to promote restoring the tissue. A thorough analysis is required to find out the architectural features of scaffolds that are essential to make the treatment successful. The current review aims to target this challenge. The article highlights different optimization approaches of nanofibrous scaffolds for improved cartilage tissue engineering. In this context, the influence of the architecture of nanoscaffolds on performance is discussed in detail. Finally, based on the gathered information, a future outlook is provided to catalyze development in this promising field.


Assuntos
Cartilagem Articular , Nanofibras , Cartilagem Articular/fisiologia , Tecidos Suporte/química , Engenharia Tecidual , Matriz Extracelular
20.
J Agric Food Chem ; 71(4): 1907-1920, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36652295

RESUMO

Agricultural biomass wastes are an abundant feedstock for biorefineries. However, most of these wastes are not treated in the right way. Here, corn stalks (CSs) were assigned as the raw material to produce cellulose nanofibers (CNFs) via in situ Fenton oxidation treatment. In order to probe the formation mechanism of an in situ Fenton reactor, the bonding interaction of hydrated Fe2+ ions and fiber has been systemically studied based on adsorption experiments, IR spectroscopy, density functional theory (DFT) calculations, and Raman spectroscopy. The results indicate that the coordination of the hydrated Fe2+ ion to the fiber generates a quasi-octahedral-coordinated sphere around the Fe center. The Jahn-Teller distortion effect of the Fe center promotes the Fe-O2H2 bonding interaction via reduction of the energy gap of the dz2 orbital of the Fe center and π2py/π2pz orbitals of the H2O2 molecule. The oxidation treatment of the pretreated CS by the in situ Fenton process shows the formation of a new carboxyl group on the fiber surface. The scanning electron microscopy image shows that the Fenton-treated fiber was scattered into the nanosized CNFs with a diameter of up to 50 nm. Both experimental and theoretical studies show that the pseudo-first-order kinetic reaction could describe the in situ Fenton kinetics well. Moreover, the proposed catalytic cycle shows that the large thermodynamic barrier is the cleavage of the O-O bond of H2O2 to generate the •OH radical, and the whole catalytic cycle is found to be spontaneous at room temperature.


Assuntos
Ferro , Nanofibras , Ferro/química , Zea mays , Celulose , Peróxido de Hidrogênio/química , Oxirredução , Modelos Teóricos
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