RESUMO
Mauritia flexuosa (Buriti) vegetable oil (OV) has attracted technological interest in various sectors, including pharmaceuticals, food, and beverages, because of its excellent antioxidant activity. The active OV components are fatty compounds, and stability is required for proper application. In this work, we investigated OV-in-water Pickering emulsions stabilized by cellulose nanofibrils (CNF). CNF is sustainable, economically viable, and environmentally friendly, and it is suitable for developing products in an eco-friendly way. The factorial design of experiments (DoE) indicates that the amount of CNF and the homogenization time significantly affect the emulsion, preventing coalescence over 30 days. Fourier-transform Raman spectroscopy (FT-Raman) and Fourier-transform infrared spectroscopy (FTIR) show that CNF stabilizes the OV droplets through induced dipole-dipole interactions and hydrogen bonds. Rheological analysis was relevant to the relationship between internal microstructure strength and viscous flow behavior of the emulsions. A novel approach enabled the identification of the CNF stabilization mechanism in the emulsion system via fluorescence microscopy. Diameter distribution measurements and steady-state rheological tests indicate that the emulsions have good stability at room temperature and suitable steady-state viscosity for food applications and beverage products as they show pronounced shear thinning behavior for cream and lotion skin care products.
Assuntos
Anti-Infecciosos , Celulose , Emulsões , Nanofibras , Óleos de Plantas , Água , Emulsões/química , Celulose/química , Nanofibras/química , Óleos de Plantas/química , Água/química , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Reologia , ViscosidadeRESUMO
This study investigates the temperature-triggered properties and phase behavior of poly(di(ethylene glycol) methyl ether methacrylate) (PDEGMA) grafted onto cellulose nanofibrils (CNF) before and after the removal of water-soluble cellulose derivatives. Mass conversion and 1H NMR analyses revealed that removing soluble molecules from the pristine nanofibril suspension decreased the quantity of free PDEGMA chains in the solution. Besides, cryogenic transmission electron microscopy (cryo-TEM) imaging above the lower critical solution temperature (LCST) highlighted the formation of unbound PDEGMA globular aggregates through the association of dehydrated chains and increased CNF thickness due to the grafting. Rheology and phase behavior analyses showed significant changes above LCST, with a higher concentration of free chains favoring the collapse of the CNF network at 35 °C. The proposed mechanism suggests that free polymer chains help to bridge neighboring fibrils, producing a robust hydrogel at lower solid content. These findings highlight the role of cellulose residues in grafting reactions and their impact on the structure and flow properties of the materials.
Assuntos
Celulose , Nanofibras , Polietilenoglicóis , Nanofibras/química , Celulose/química , Polietilenoglicóis/química , Reologia , Temperatura , Metacrilatos/químicaRESUMO
Chitosan (CS) is a promising polymeric biomaterial for use in scaffolds forin vitroskin models and wound dressings, owing to its non-antigenic and antimicrobial properties. However, CS often exhibits insufficient physicochemical properties, mechanical strength, and bioactivity, limiting its efficacy in demanding applications. To address these challenges, cotton cellulose nanofibers (CNFs) represent a promising nanomaterial for enhancing CS-based scaffolds in tissue engineering. CNF offers superior stiffness, and mechanical properties that enhance cellular adhesion and proliferation, both crucial for effective tissue regeneration and healing. This study aimed to develop and characterize a scaffold combining cotton CNF and CS, focusing on its cytocompatibility with human fibroblasts and keratinocytes. The cotton CNF/CS scaffold was fabricated using the casting technique, and its physicochemical properties and cellular compatibility were assessedin vitro. The results demonstrated that incorporating cotton CNF significantly enhanced the stability of the CS matrix. The CS scaffold with 1000 µg ml-1of cotton CNF exhibited increased roughness and reduced rupture strain compared to the pure CS scaffold. The cotton CNF/CS scaffold effectively promoted the adhesion, viability, proliferation, migration, and collagen synthesis of skin cells. Notably, increased cell viability was observed in human fibroblasts cultured on scaffolds with higher concentrations of cotton CNF (100 and 1000 µg ml-1). Based on the findings, the cotton CNF/CS scaffold demonstrates enhanced physicochemical properties and bioactivity, making it a promising candidate for the development ofin vitrohuman skin models and wound healing dressings.
Assuntos
Materiais Biocompatíveis , Adesão Celular , Proliferação de Células , Sobrevivência Celular , Celulose , Quitosana , Fibroblastos , Queratinócitos , Nanofibras , Pele , Engenharia Tecidual , Alicerces Teciduais , Cicatrização , Quitosana/química , Cicatrização/efeitos dos fármacos , Humanos , Nanofibras/química , Engenharia Tecidual/métodos , Alicerces Teciduais/química , Fibroblastos/citologia , Celulose/química , Materiais Biocompatíveis/química , Queratinócitos/citologia , Teste de Materiais , Fibra de Algodão , Bandagens , Resistência à Tração , Colágeno/químicaRESUMO
The objective of this research was to assess the potential of a Pickering emulsion based on lycopene extracted from guava by sunflower oil-water and cellulose nanofibers (CNFs) isolated from banana residues as a novel ingredient for a French-style salad dressing. The aim was to determine the impact of this emulsion on the stability and rheological properties of the dressing as well as ascertain the presence of lycopene in the final product. The particle size distribution, rheological properties, and emulsion stability of the Pickering emulsion and salad dressing were evaluated. The sample exhibiting the optimal stability condition contained 0.5 wt.% of CNFs (EPI0.5). In order to prepare the French salad dressing based on this Pickering emulsion, three concentrations of vinegar were analyzed. All samples contained white salt and sugar. The findings suggest that alterations in emulsion stability may be influenced by the vinegar content and the presence of salt, particularly during the storage period, which also affects the concentration of lycopene. Notwithstanding these findings, the untrained panelists expressed a favorable opinion and acceptance of the dressings, indicating that the product could serve as an alternative means of enriching food through the incorporation of beneficial substances such as lycopene.
Assuntos
Celulose , Emulsões , Licopeno , Nanofibras , Psidium , Licopeno/química , Celulose/química , Emulsões/química , Nanofibras/química , Psidium/química , Água/química , Tamanho da Partícula , Reologia , Óleo de Girassol/química , Carotenoides/química , Ácido Acético/químicaRESUMO
OBJECTIVES: To evaluate the feasibility of using a 3D model with human dental pulp cells (HDPCs) to compare bleaching therapies and assess whether coating enamel with a nanofiber scaffold (NS) and polymeric catalyst primer (PCP), combined with violet LED (LEDv) irradiation, enhances bleaching efficacy (BE) and reduces cytotoxicity (CT). MATERIALS AND METHODS: After using NS + PCP to cover enamel of enamel/dentin discs adapted to artificial pulp chambers containing 3D culture with HDPCs, a bleaching gel with 35%H2O2 was applied and then irradiated with LEDv. The following groups were established (n = 8): NC - no treatment; PC- 35%H2O2 for 45 min, and EXP: NS + PCP + 35%H2O2 + LEDv for 15 min. The study evaluated BE (ΔE00 and ΔWID), CT (alamarBlue), and HDPCs gene modulation (TNF, IL1B, PTGS2, IL8, IL6, PPRAG, HMOX1, DSPP, DMP1, SPP1, BGLAP, and ALPL; RTqPCR). RESULTS: BE showed no significant difference between PC and EXP (p > 0.05). EXP had lower oxidative stress, higher cell viability, reduced inflammatory marker expression, and increased mineralization marker expression compared to PC (p < 0.05). CONCLUSION: The 3D model using HDPCs effectively compared bleaching protocols. Coating enamel with NS + PCP and applying violet LED (LEDv) reduced bleaching time from 45 to 15 min while lowering cytotoxicity compared to conventional in-office treatments. CLINICAL RELEVANCE: This study shows that a 3D model with human dental pulp cells (HDPCs) effectively compares tooth bleaching protocols. The combination of a nanofiber scaffold with violet LED (LEDv) reduces bleaching time, as well as minimizes cytotoxicity and inflammation, offering a safer alternative to conventional treatments.
Assuntos
Técnicas de Cultura de Células em Três Dimensões , Polpa Dentária , Peróxido de Hidrogênio , Nanofibras , Clareadores Dentários , Clareamento Dental , Humanos , Clareamento Dental/métodos , Polpa Dentária/citologia , Peróxido de Hidrogênio/farmacologia , Clareadores Dentários/farmacologia , Expressão Gênica , Estudos de Viabilidade , Esmalte Dentário/efeitos dos fármacos , Células Cultivadas , Sobrevivência Celular/efeitos dos fármacos , Alicerces TeciduaisRESUMO
Magnesium-doped hydroxyapatite (HAp-Mg) nanofibers show promise for medical applications due to their structural similarity to bone minerals and enhanced biological properties, such as improved biocompatibility and antimicrobial activity. This study synthesized HAp-Mg nanofibers using a microwave-assisted hydrothermal method (MAHM) to evaluate their cytotoxicity, biocompatibility, and antimicrobial efficacy compared to commercial hydroxyapatite (HAp). Characterization through X-ray diffraction (XRD), scanning electron microscopy (SEM), Transmission Electron Microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), and Fourier transform infrared spectroscopy (FTIR) confirmed the successful incorporation of magnesium, producing high-purity, crystalline nanofibers with hexagonal morphology. Rietveld refinement showed slight lattice parameter shortening, indicating Mg2+ ion integration. Cell viability assays (MTT and AlamarBlue) revealed a significant increase in fibroblast proliferation with 2% and 5% HAp-Mg concentrations compared to controls (p < 0.05), demonstrating non-cytotoxicity and enhanced biocompatibility. Antimicrobial tests (disk diffusion method, 100 µg/mL) showed that HAp-Mg had strong antibacterial effects against Gram-positive and Gram-negative bacteria and moderate antifungal activity against Candida albicans. In contrast, commercial HAp showed no antimicrobial effects. These results suggest HAp-Mg nanofibers have significant advantages as biomaterials for medical applications, particularly in preventing implant-related infections and supporting further clinical development.
Assuntos
Anti-Infecciosos , Candida albicans , Durapatita , Magnésio , Nanofibras , Durapatita/química , Nanofibras/química , Magnésio/química , Anti-Infecciosos/farmacologia , Anti-Infecciosos/química , Candida albicans/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Testes de Sensibilidade Microbiana , Camundongos , Difração de Raios X , Fibroblastos/efeitos dos fármacos , Espectroscopia de Infravermelho com Transformada de Fourier , HumanosRESUMO
Nitric oxide (NO) holds promise for wound healing due to its antimicrobial properties and role in promoting vasodilation and tissue regeneration. The local delivery of NO to target cells or organs offers significant potential in numerous biomedical applications, especially when NO donors are integrated into nontoxic viscous matrices. This study presents the development of robust cellulose nanofibril (CNF) hydrogels designed to control the release of nitric oxide (NO) generated in situ from a NO-donor molecule (S-nitrosoglutathione, GSNO) obtained from the nitrosation of its precursor molecule glutathione (GSH). CNF, efficiently isolated from sugar cane bagasse, exhibited a high aspect ratio and excellent colloidal stability in water. Although depletion forces could be observed upon the addition of GSH, this effect did not significantly alter the morphology of the CNF network at low GSH concentrations (<20 mM). Ionic cross-linking with Ca2+ resulted in nontoxic and robust hydrogels (elastic moduli ranging from 300 to 3000 Pa) at low CNF solid content. The release rate of NO from GSNO decreased in CNF from 1.61 to 0.40 mmol. L-1·h-1 when the nanofibril content raised from 0.3 to 1.0 wt %. The stabilization effect monitored for 16 h was assigned to hydrogel mesh size, which was easily tailored by modifying the concentration of CNF in the initial suspension. These results highlight the potential of CNF-based hydrogels in biomedical applications requiring a precise NO delivery.
Assuntos
Materiais Biocompatíveis , Cálcio , Celulose , Hidrogéis , Teste de Materiais , Nanofibras , Óxido Nítrico , Hidrogéis/química , Hidrogéis/farmacologia , Óxido Nítrico/metabolismo , Óxido Nítrico/química , Celulose/química , Nanofibras/química , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Cálcio/química , Cálcio/metabolismo , Tamanho da Partícula , Reagentes de Ligações Cruzadas/químicaRESUMO
Ultrathin fibers have been used to design functional nanostructured materials for technological and biomedical applications. Combining the use of renewable and compatible sources with the emerging alternative SBS (solution blow spinning) technique opens new opportunities for material applications. In this review, we introduce the benefits of SBS over the classical electrospinning technique by following studies that use collagen or gelatin. SBS offers distinct advantages over electrospinning in the preparation of ultrathin fibers based on natural proteins, including the absence of high-voltage sources and the possibility of using fewer toxic solvents. Notably, there is also the prospect of using SBS directly in injured tissues, opening new strategies for in situ structure assembly SBS is a suitable approach to produce fibers at the nanoscale that can be tailored to distinct diameters by blending or simply adjusting experimental conditions. The focus on producing collagen or gelatin fibers contributes to designing highly biocompatible mats with potential for promoting cellular growth and implantation, even though their applications can be found also in food packaging, energy, and the environment. Therefore, a comprehensive analysis of the topic is essential to evaluate the current strategies regarding these materials and allow for their expanded production and advanced applications.
Assuntos
Materiais Biocompatíveis , Colágeno , Gelatina , Gelatina/química , Colágeno/química , Materiais Biocompatíveis/química , Nanofibras/química , Animais , Engenharia Tecidual/métodos , Humanos , SoluçõesRESUMO
Food contamination by mycotoxigenic fungi is one of the principal factors that cause food loss and economic losses in the food industry. The objective of this work was to incorporate the essential oil from Corymbia citriodora Hook and its constituents citronellal and ß-citronellol into poly(lactic acid) nanofibers; to characterize the nanofibers by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy and differential scanning calorimetry; to evaluate the antifungal activity by the fumigation method; to evaluate the antimycotoxigenic activity against Aspergillus carbonarius, Aspergillus ochraceus, Aspergillus westerdijkiae, Aspergillus flavus, and Aspergillus parasiticus; and to evaluate the morphology of these microorganisms. All the nanofibers had a regular, smooth, and continuous morphology. FTIR analyses confirmed that the active ingredients were incorporated into the polymer matrix. All samples exhibited antifungal and ochratoxigenic inhibitory activities of up to 100% and 99%, respectively, with the best results observed for (PLA + 30 wt% ß-citronellol) nanofibers and (PLA + 30 wt% citronellal) nanofibers. However, 100% inhibition of the production of aflatoxin B1 and B2 was not observed. The images obtained by SEM indicated that the nanofibers caused damage to the hyphae, caused a decrease in the production of spores, and caused deformation, rupture, and non-formation of the conid head, might be an alternative for the control of mycotoxigenic fungi.
Assuntos
Monoterpenos Acíclicos , Antifúngicos , Aspergillus , Nanofibras , Óleos Voláteis , Poliésteres , Nanofibras/química , Poliésteres/química , Poliésteres/farmacologia , Óleos Voláteis/farmacologia , Óleos Voláteis/química , Antifúngicos/farmacologia , Antifúngicos/química , Monoterpenos Acíclicos/farmacologia , Monoterpenos Acíclicos/química , Aspergillus/efeitos dos fármacos , Aldeídos/farmacologia , Aldeídos/química , Testes de Sensibilidade Microbiana , Monoterpenos/farmacologia , Monoterpenos/químicaRESUMO
Olive pomace (OP) waste, produced in large quantities, contains significant amounts of cellulose and fibers, making it a valuable resource for developing reinforcing ingredients in biodegradable packaging materials. This study aimed to produce nanofibers from OP using enzymatic hydrolysis with hemicellulases and cellulases, and to incorporate these nanofibers into starch films as a reinforcing agent. Cellulose nanofibers (CNFs) were prepared by alkaline pretreatment followed by enzymatic hydrolysis (with hemicellulases and cellulases) from olive pomace and applied as reinforcement in starch films in concentrations of 0.5%-5% (w/v). The nanofibers were analyzed according to composition, structural, and thermal properties. The nanofibers' suspension presented a cloudy and white color in aqueous suspension, the X-ray diffraction (XRD) analysis showed the increase of crystallinity, and the fibers' range was no wider than 100 nm (according to Scherer equation). The composition analysis showed the decrease of carbonyl groups of hemicellulose and lignin. The starch films presented a homogenous surface. The solubility from these biodegradable films significantly reduced after the incorporation of CNF, and the nanomaterial's presence improved the degradation temperature (from 310°C to 322°C) and the mechanical resistance because the tension of rupture increased from 3.79 to 6.21 MPa. PRACTICAL APPLICATION: The utilization of waste from the olive pomace for cellulose nanofiber production holds promise, given the nanofibers' ability to readily integrate into various materials, including starches used in biodegradable film production. Within these matrices, nanofibers act as structure reinforcers and significantly reduce the solubility of films. Although biodegradable films ensure the shelf life, safety, and quality of food, their properties currently do not match those of traditional petroleum-based materials at an industrial scale, indicating a need for further enhancement.
Assuntos
Celulose , Embalagem de Alimentos , Nanofibras , Olea , Amido , Nanofibras/química , Celulose/química , Olea/química , Amido/química , Hidrólise , Embalagem de Alimentos/métodos , Glicosídeo Hidrolases/química , Celulases/química , Difração de Raios X , SolubilidadeRESUMO
Cellulose micro/nanofibril (MNFC) films are an interesting alternative to plastic-based films for application in biodegradable packaging. In this study, we aimed to produce and characterize MNFC films obtained from alkaline-pretreated rubberwood (Hevea brasiliensis) waste and Eucalyptus sp. commercial pulp. MNFC and films were evaluated regarding microstructure; crystallinity; stability; and physical, optical, mechanical, and barrier properties. A combined quality index (QI) was also calculated. Eucalyptus MNFC suspensions were more stable than H. brasiliensis. Both films had a hydrophobic surface (>90°) and high grease resistance (oil kit 12). H. brasiliensis films had lower transparency (26.4 %) and high crystallinity (â¼89 %), while Eucalyptus films had lower permeability and higher mechanical strength. The QI of MNFC was 51 ± 5 for H. brasiliensis and 55 ± 4 for Eucalyptus, showing that both types of raw material have potential for application in the packaging industry and in the reinforcement of composites, as well as for high value-added applications in products made from special materials.
Assuntos
Celulose , Hevea , Nanofibras , Celulose/química , Hevea/química , Nanofibras/química , Permeabilidade , Eucalyptus/química , Embalagem de Produtos , Resistência à Tração , Interações Hidrofóbicas e HidrofílicasRESUMO
Electrospinning is a process in which high voltage creates nanostructured fibers with random orientation from a polymer solution. A novel electrospinning instrument was designed and constructed, capable of orienting and collimating the trajectory of the electrified fluid jet. The equipment collimates and adjusts the electrified fluid jet in the X-Y directions using deflector plates connected to a variable electric field. Simultaneously, different membrane thicknesses can be selected, i.e., in the Z direction. Additionally, by programming the sinusoidal function generator to perform an X-Y sweep, Lissajous figures (LF) were obtained. SEM images obtained through XYZ electrospinning of PVC and PVDF membranes were used to determine the control achieved over the orientation distribution of the processed nanofibers and the modification of their diameter, with and without applying the electric field to the deflector plates. The nanofibers obtained from the polymeric membranes, which originated after the straight segment of the Taylor cone, did not exhibit a random trajectory and position. Instead, the collimated electrified fluid jet deposited them in a cross pattern (X-Y) on the collector-cathode plate.
Assuntos
Eletricidade , Nanofibras , Polímeros , Nanofibras/química , Polímeros/química , Cloreto de Polivinila/química , Polivinil/química , Polímeros de FluorcarbonetoRESUMO
Cardiovascular diseases, particularly myocardial infarction, have significant healthcare challenges due to the limited regenerative capacity of injured heart tissue. Cardiac tissue engineering (CTE) offers a promising approach to repairing myocardial damage using biomaterials that mimic the heart's extracellular matrix. This study investigates the potential of graphene nanopowder (Gnp)-enhanced polycaprolactone (PCL) scaffolds fabricated via electrospinning to improve the properties necessary for effective cardiac repair. This work aimed to analyze scaffolds with varying graphene concentrations (0.5%, 1%, 1.5%, and 2% by weight) to determine their morphological, chemical, mechanical, and biocompatibility characteristics. The results presented that incorporating graphene improves PCL scaffolds' mechanical properties and cellular interactions. The optimal concentration of 1% graphene significantly enhanced mechanical properties and biocompatibility, promoting cell adhesion and proliferation. These findings suggest that Gnp-enhanced PCL scaffolds at this concentration can serve as a potent substrate for CTE providing insights into designing more effective biomaterials for myocardial restoration.
Assuntos
Proliferação de Células , Grafite , Nanofibras , Poliésteres , Engenharia Tecidual , Alicerces Teciduais , Engenharia Tecidual/métodos , Grafite/química , Poliésteres/química , Proliferação de Células/efeitos dos fármacos , Materiais Biocompatíveis , Adesão Celular/efeitos dos fármacos , Teste de Materiais , Animais , Miócitos Cardíacos/efeitos dos fármacos , Humanos , Miocárdio/patologiaRESUMO
The evaluation of the photocatalytic properties of electrospun TiO2 nanofibres (TiO2-NFs) synthesised in the same experimental conditions using two distinct precursors, tetraisopropyl orthotitanate (TTIP) and tetrabutyl orthotitanate (TNBT), with morphology and crystalline structure controlled by annealing at 460 °C for 3 h is presented. The presence of circular-shaped TiO2-NFs was corroborated by scanning electron microscopy (SEM). By using X-ray photoelectron spectroscopy (XPS), the chemical binding energies and their interactions of the TiO2 with the different incorporated impurities were determined; the most intense photoelectronic transitions of Ti 2p3/2 (458.39 eV), O 1 s (529.65 eV) and C 1 s (284.51 eV) were detected for TTIP and slightly blue-shifted for TNBT. By using energy-dispersive X-ray spectroscopy (EDS), the chemical element percentages in TiO2 were determined. Using X-ray diffraction, it was found that the annealed electrospun TiO2-NFs presented the anatase crystalline phase and confirmed by Raman scattering. Bandgap energies were determined by diffuse reflectance spectroscopy at room temperature. The photocatalytic degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) herbicide under exposure to ultraviolet light was studied using the TiO2-NFs obtained with the two molecular precursors. The results showed that the catalyst, prepared with the TTIP precursor, turned out to be the one that presented the highest photocatalytic activity with a half-life time (t1/2) of 28 min and a degradation percentage of 93%. The total organic carbon (TOC) in the solutions resulting from the 2,4-D degradation by the TiO2-NFs was measured, which showed a TOC removal of 50.67% for the TTIP sample and 36.14% for the TNBT sample. Finally, by using FTIR spectroscopy, the final chemical compounds of the degradation were identified as H2O and CO2.
Assuntos
Ácido 2,4-Diclorofenoxiacético , Nanofibras , Titânio , Titânio/química , Nanofibras/química , Ácido 2,4-Diclorofenoxiacético/química , CatáliseRESUMO
Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) nanofibers embedded with borate glasses of 45B5 composition doped with Co2+, Cu2+, and Zn2 +(46.1 B2O326.9-X CaO24.4 Na2O2.6 P2O5, X CoO/CuO/ZnO mol % (X = 0-5)) were produced by electrospinning for wound healing applications. Prior to their addition, the glasses exhibited two broad halos typical of a vitreous borate network, which were mainly composed of ring-type metaborate structural units. The particle distribution in the PHBV nanofibers embedded with 45B5 borate bioactive glasses is present in isolated and agglomerated states, being partially coated by a polymeric layer-except for the cobalt-doped glass, which resulted in a successful encapsulation with 100% embedding efficiency. The incorporation of the glasses reduced the PHBV crystallinity degree and its decomposition temperature, as well as its mechanical properties, including Young's modulus, tensile strength, and elongation at break. The neat PHBV fibers and those containing the cobalt-doped glasses demonstrated great cytocompatibility with human keratinocytes (HaCat), as suggested by the high cell viability after 7 days of exposure. Further studies are needed to fully understand the wound healing potential of these fibers, but our results significantly contribute to the area.
Assuntos
Bandagens , Boratos , Cobalto , Cobre , Poliésteres , Zinco , Humanos , Cobre/química , Cobalto/química , Poliésteres/química , Boratos/química , Zinco/química , Vidro/química , Teste de Materiais , Cicatrização , Nanofibras/química , Linhagem Celular , Poli-HidroxibutiratosRESUMO
BACKGROUND: Folic acid (FA), a synthetically produced compound analogous to vitamin B9, also referred to as vitamin folate, is an essential compound in human health and faces challenges in stability during food processing. This study explores the incorporation of FA into carboxymethylcellulose (CMC) nanofibers using electrospinning to enhance its stability. RESULTS: In this study, optimization of both electrospinning and solution parameters facilitated the fabrication of nanofibers. Furthermore, incorporating FA into CMC/polyethylene oxide (PEO) nanofibers resulted in thinner fibers, with an average diameter of 88 nm, characterized by a flat shape and smooth surface. Fourier transform infrared spectroscopic analysis demonstrated substantial hydrogen bonding interactions between FA and the polar groups present in CMC. This interaction contributed to an encapsulation efficiency of 94.5%, with a yield exceeding 87%. Thermal analysis highlighted mutual interference between CMC and PEO, with FA enhancing the thermal stability and reducing the melting temperatures and enthalpies of PEO, while also increasing the reaction heats of CMC. The encapsulated FA remained stable in acidic conditions, with only 6% degradation over 30 days, demonstrating the efficacy of CMC/PEO nanofibers in safeguarding FA against acidic environments. Moreover, the nanofibers provided a protective barrier against UV radiation, thereby preserving the stability of FA. CONCLUSION: This study emphasizes the efficacy of CMC/PEO nanofibers as a protective matrix against FA degradation. The findings indicate that this innovative approach could significantly diversify the applications of FA in food fortification, addressing concerns regarding its vulnerability to temperature and hydrolysis reactions during food processing. © 2024 Society of Chemical Industry.
Assuntos
Carboximetilcelulose Sódica , Ácido Fólico , Nanofibras , Polietilenoglicóis , Nanofibras/química , Ácido Fólico/química , Carboximetilcelulose Sódica/química , Polietilenoglicóis/química , Estabilidade de Medicamentos , Liberação Controlada de Fármacos , Portadores de Fármacos/química , Composição de Medicamentos/métodosRESUMO
INTRODUCTION AND OBJECTIVES: There are different situations in which an extrahepatic bile duct replacement or substitute is needed, such as initial and localized stages of bile duct cancer, agenesis, stenosis, or bile duct disruption. MATERIALS AND METHODS: A prosthesis obtained by electrospinning composed of Poly (D,L-lactide-co-glycolide) (PGLA) - Polycaprolactone (PCL) - Gelatin (Gel) was developed, mechanical and biological tests were carried out to evaluate resistance to tension, biocompatibility, biodegradability, cytotoxicity, morphological analysis and cell culture. The obtained prosthesis was placed in the extrahepatic bile duct of 15 pigs with a 2-year follow-up. Liver function tests and cholangioscopy were evaluated during follow-up. RESULTS: Mechanical and biological evaluations indicate that this scaffold is biocompatible and biodegradable. The prosthesis implanted in the experimental model allowed cell adhesion, migration, and proliferation, maintaining bile duct permeability without altering liver function tests. Immunohistochemical analysis indicates the presence of biliary epithelium. CONCLUSIONS: A tubular scaffold composed of electrospun PGLA-PCL-Gel nanofibers was used for the first time to replace the extrahepatic bile duct in pigs. Mechanical and biological evaluations indicate that this scaffold is biocompatible and biodegradable, making it an excellent candidate for use in bile ducts and potentially in other tissue engineering applications.
Assuntos
Implantes Absorvíveis , Ductos Biliares Extra-Hepáticos , Gelatina , Poliésteres , Engenharia Tecidual , Alicerces Teciduais , Animais , Ductos Biliares Extra-Hepáticos/cirurgia , Engenharia Tecidual/métodos , Suínos , Teste de Materiais , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Proliferação de Células , Desenho de Prótese , Materiais Biocompatíveis , Movimento Celular , Adesão Celular , Fatores de Tempo , Testes de Função Hepática , NanofibrasRESUMO
Persistent bacterial infections are the leading risk factor that complicates the healing of chronic wounds. In this work, we formulate mixtures of polyvinyl alcohol (P), chitosan (CH), collagen (C), and honey (H) to produce nanofibrous membranes with healing properties. The honey effect at concentrations of 0 % (PCH and PCHC), 5 % (PCHC-5H), 10 % (PCHC-10H), and 15 % (PCHC-15H) on the physicochemical, antibacterial, and biological properties of the developed nanofibers was investigated. Morphological analysis by SEM demonstrated that PCH and PCHC nanofibers had a uniform and homogeneous distribution on their surfaces. However, the increase in honey content increased the fiber diameter (118.11-420.10) and drastically reduced the porosity of the membranes (15.79-92.62 nm). The addition of honey reduces the water vapor transmission rate (WVTR) and the adsorption properties of the membranes. Mechanical tests revealed that nanofibers were more flexible and elastic when honey was added, specifically the PCHC-15H nanofibers with the lowest modulus of elasticity (15 MPa) and the highest elongation at break (220 %). Also, honey significantly improved the antibacterial efficiency of the nanofibers, mainly PCHC-15H nanofibers, which presented the best bacterial reduction rates against Staphylococcus aureus (59.84 %), Pseudomonas aeruginosa (47.27 %), Escherichia coli (65.07 %), and Listeria monocytogenes (49.58 %). In vitro tests with cell cultures suggest that nanofibers were not cytotoxic and exhibited excellent biocompatibility with human fibroblasts (HFb) and keratinocytes (HaCaT), since all treatments showed higher or similar cell viability as opposed to the cell control. Based on the findings, PVA-chitosan-collagen-honey nanofibrous membranes have promise as an antibacterial dressing substitute.
Assuntos
Antibacterianos , Bandagens , Quitosana , Colágeno , Mel , Membranas Artificiais , Nanofibras , Cicatrização , Quitosana/química , Quitosana/farmacologia , Nanofibras/química , Bandagens/microbiologia , Colágeno/química , Antibacterianos/farmacologia , Antibacterianos/química , Humanos , Cicatrização/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Porosidade , Álcool de Polivinil/química , Fibroblastos/efeitos dos fármacosRESUMO
Hemicellulose plays a key role in both the production of cellulose nanofibrils (CNF) and their properties as suspensions and films. While the use of enzymatic and chemical pre-treatments for tailoring hemicellulose levels is well-established, post-treatment methods using enzymes remain relatively underexplored and hold significant promise for modifying CNF film properties. This study aimed to investigate the effects of enzymatic xylan removal on the properties of CNF film for packaging applications. The enzymatic post-treatment was carried out using an enzymatic cocktail enriched with endoxylanase (EX). The EX post-treated-CNFs were characterized by LALLS, XRD, and FEG-SEM, while their films were characterized in terms of physical, morphological, optical, thermal, mechanical, and barrier properties. Employing varying levels of EX facilitated the hydrolysis of 8 to 35 % of xylan, yielding CNFs with different xylan contents. Xylan was found to be vital for the stability of CNF suspensions, as its removal led to the agglomeration of nanofibrils. Nanostructures with preserved crystalline structures and different morphologies, including nanofibers, nanorods, and their hybrids were observed. The EX post-treatment contributed to a smoother film surface, improved thermostability, and better moisture barrier properties. However, as the xylan content decreased, the films became lighter (lower grammage), less strong, and more brittle. Thus, the enzymatic removal of xylan enabled the customization of CNF films' performance without affecting the inherent crystalline structure, resulting in materials with diverse functionalities that could be explored for use in packaging films.
Assuntos
Celulose , Nanofibras , Xilanos , Xilanos/química , Nanofibras/química , Celulose/química , Hidrólise , Endo-1,4-beta-Xilanases/química , Endo-1,4-beta-Xilanases/metabolismoRESUMO
Essential oils show several biological properties, such as antimicrobial activity, but have limitations regarding their availability and stability. To maximize their antimicrobial effect and protection against environmental conditions, Pickering-type emulsions were used to vehiculate oregano essential oil (OEO) using cellulose nanofibers (CNF) as emulsion stabilizer. Enzymatic hydrolysis was used to produce CNF from a food industry waste (cassava peel), obtaining an environmentally sustainable emulsion stabilizer. It was evaluated how the different properties of the nanofibers affected the stability of the emulsions. Furthermore, the composition of the dispersed phase was varied (different ratios of OEO and sunflower oil-SO) in view of the target application in biodegradable active coatings. Even at very low concentration (0.01 % w/w), CNF was able to form kinetically stable emulsions with small droplet sizes using oil mixtures (OEO + SO). The stabilization mechanism was not purely Pickering, as there was a reduction in interfacial tension. Excellent antimicrobial activity was observed against bacteria and the fungus Alternaria alternata, demonstrating the ability to apply these emulsions in active systems such as coatings and films. An improvement in the stability of emulsions was observed when using a mixture of oils, which is extremely advantageous considering costs and stability to heat treatments, since the desired antimicrobial activity is maintained for the final application.