RESUMEN
Using supramolecular self-assembled nanocomposite materials made from protein and polysaccharide components is becoming more popular because of their unique properties, such as biodegradability, hierarchical structures, and tunable multifunctionality. However, the fabrication of these materials in a reproducible way remains a challenge. This study presents a new evaporation-induced self-assembly method producing layered hydrogel membranes (LHMs) using tropocollagen grafted by partially deacetylated chitin nanocrystals (CO-g-ChNCs). ChNCs help stabilize tropocollagen's helical conformation and fibrillar structure by forming a hierarchical microstructure through chemical and physical interactions. The LHMs show improved mechanical properties, cytocompatibility, and the ability to control drug release using octenidine dihydrochloride (OCT) as a drug model. Because of the high synergetic performance between CO and ChNCs, the modulus, strength, and toughness increased significantly compared to native CO. The biocompatibility of LHM was tested using the normal human dermal fibroblast (NHDF) and the human osteosarcoma cell line (Saos-2). Cytocompatibility and cell adhesion improved with the introduction of ChNCs. The extracted ChNCs are used as a reinforcing nanofiller to enhance the performance properties of tropocollagen hydrogel membranes and provide new insights into the design of novel LHMs that could be used for various medical applications, such as control of drug release in the skin and bone tissue regeneration.
Asunto(s)
Hidrogeles , Humanos , Hidrogeles/química , Hidrogeles/farmacología , Nanopartículas/química , Quitina/química , Línea Celular Tumoral , Materiales Biocompatibles/química , Materiales Biocompatibles/farmacología , Fibroblastos/efectos de los fármacos , Fibroblastos/citología , Membranas Artificiales , Nanocompuestos/química , Adhesión Celular/efectos de los fármacosRESUMEN
A highly efficient, bio-ecofriendly, and transparent flame retardant (FR) for cotton fabric was developed and deposited onto the cellulose skeletal structure of cotton fabric through a one-pot sol-gel process. The flame retardant functional coating is composed of ammonium polyphosphate (APP), guar gum (GG), citric acid (CA), and a negligible amount of catalyst. Cotton fabrics were impregnated with different concentrations of ammonium polyphosphate and guar gum, with citric acid as a crosslinking agent. The overall crosslinking and grafting process was proven by FTIR and XPS. Based on the results, the designed coating exhibits over 90 % transmittance in the visible region. A 15 g/m2 flame-retardant coating induces excellent flame retardant efficiency at ultra-low flame-retardant concentrations of less than 6.25 wt%. Only a 5.25 wt% flame retardant concentration demonstrated condensed phase action, which resulted in 58.5 % and 73.6 % reductions in the pHRR and THR, respectively. Moreover, the limiting oxygen index (LOI) value showed a 74 % increase. The mechanical performance of FR coated cotton fibers was slightly reduced.
Asunto(s)
Compuestos de Amonio , Retardadores de Llama , Ácido Cítrico , Polifosfatos/químicaRESUMEN
The marine-derived hyaluronic acid and other natural biopolymers offer exciting possibilities in the field of biomaterials, providing sustainable and biocompatible alternatives to synthetic materials. Their unique properties and abundance in marine sources make them valuable resources for various biomedical and industrial applications. Due to high biocompatible features and participation in biological processes related to tissue healing, hyaluronic acid has become widely used in tissue engineering applications, especially in the wound healing process. The present review enlightens marine hyaluronan biomaterial providing its sources, extraction process, structures, chemical modifications, biological properties, and biocidal applications, especially for wound healing/dressing purposes. Meanwhile, we point out the future development of wound healing/dressing based on hyaluronan and its composites and potential challenges.
Asunto(s)
Vendajes , Ácido Hialurónico , Ácido Hialurónico/farmacología , Materiales Biocompatibles/farmacología , Ingeniería de Tejidos , Cicatrización de HeridasRESUMEN
The multiple roles of organic nanofillers in biodegradable nanocomposites (NC) with a blend-based matrix is not yet fully understood. This work highlights combination of reinforcing and structure-directing effects of chitin nanowhiskers (CNW) with different degrees of deacetylation (DA), i.e., content of primary or secondary amines on their surface, in the nanocomposite with the PCL/PLA 1:1 matrix. Of importance is the fact that aminolysis with CNW leading to chain scission of both polyesters, especially of PLA, is practically independent of DA. DA also does not influence thermal stability. At the same time, the more marked chain scission/CNW grafting for PLA in comparison to PCL, causing changes in rheological parameters of components and related structural alterations, has crucial effects on mechanical properties in systems with a bicontinuous structure. Favourable combinations of multiple effects of CNW leads to enhanced mechanical performance at low 1% content only, whereas negative effects of structural changes, particularly of changed continuity, may eliminate the reinforcing effects of CNW at higher contents. The explanation of both synergistic and antagonistic effects of structures formed is based on the correspondence of experimental results with respective basic model calculations.
RESUMEN
This study presents an innovative multifunctional system in fabricating new functional wound dressing (FWD) products that could be used for skin regeneration, especially in cases of infected chronic wounds and ulcers. The innovation is based on the extraction, characterization, and application of collagen (CO)/chitosan-glucan complex hollow fibers (CSGC)/aloe vera (AV) as a novel FWS. For the first time, specific hollow fibers were extracted with controlled inner (500-900 nm)/outer (2-3 µm) diameters from mycelium of Schizophyllum commune. Further on, research and evaluation of morphology, hydrolytic stability, and swelling characteristics of CO/CSGC@AV were carried out. The obtained FWS showed high hydrolytic stability with enhanced swelling characteristics compared to native collagen. The hemostatic effect of FWS increased significantly in the presence of CSGC, compared to native CO and displayed excellent biocompatibility which was tested by using normal human dermal fibroblast (NHDF). The FWS showed high antibacterial activity against different types of bacteria (positive/negative grams). From in vivo measurements, the novel FWS increased the percentage of wound closure after one week of treatment. All these results imply that the new CO/CSGC@AV-FWD has the potential for clinical skin regeneration and applying for controlled drug release.
Asunto(s)
Aloe , Antibacterianos/farmacología , Vendajes , Quitosano/farmacología , Colágenos Fibrilares/farmacología , Glucanos/farmacología , Micelio , Extractos Vegetales/farmacología , Schizophyllum , Piel/efectos de los fármacos , Cicatrización de Heridas/efectos de los fármacos , Heridas y Lesiones/tratamiento farmacológico , Aloe/química , Animales , Antibacterianos/química , Antibacterianos/aislamiento & purificación , Bacterias/efectos de los fármacos , Bacterias/crecimiento & desarrollo , Células Cultivadas , Quitosano/química , Quitosano/aislamiento & purificación , Modelos Animales de Enfermedad , Colágenos Fibrilares/química , Colágenos Fibrilares/aislamiento & purificación , Glucanos/química , Glucanos/aislamiento & purificación , Humanos , Masculino , Micelio/química , Extractos Vegetales/química , Extractos Vegetales/aislamiento & purificación , Ratas Wistar , Schizophyllum/química , Piel/lesiones , Piel/patología , Heridas y Lesiones/patologíaRESUMEN
Thin layers of chitosan (positively charged)/sodium hyaluronate (negatively charged)/nonwoven fabrics were constructed by polyelectrolyte multilayer pad-dry-cure technique. Pure chitosan (CS) was isolated from shrimp shell and immobilized onto nonwoven fabrics (NWFs) using citric acid (CTA) as cross linker and solvent agents through a pad-dry-cure method. The prepared thin layer of chitosan citrate/nonwoven fabrics (CSCTA/NWFs) were consequently impregnated with hyaluronan (CSCTA/HA/NWFs) in the second path through a pad-dry-cure method. Chitosan/hyaluronan/nonwoven fabrics wound dressing was characterized by different techniques such as FTIR-ATR, TGA and SEM. The antibacterial activity and the cytotoxicity of the dressing sheets were evaluated against Escherichia coli (E. coli) and Streptococcus aureus (S. aureus), mouse fibroblast (NIH-3T3) and keratinocytes (HaCaT) cell lines, respectively. The cell-fabrics interaction was also investigated using fluorescence microscope, based on live/dead staining assay of 3T3 cells. The healing properties of the new wound dressing were evaluated and compared with the control sample.
Asunto(s)
Antibacterianos/química , Vendajes/microbiología , Textiles/microbiología , Cicatrización de Heridas/efectos de los fármacos , Animales , Antibacterianos/uso terapéutico , Quitosano/química , Quitosano/uso terapéutico , Escherichia coli/efectos de los fármacos , Escherichia coli/patogenicidad , Humanos , Ácido Hialurónico/química , Ácido Hialurónico/uso terapéutico , Ratones , Células 3T3 NIH , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/patogenicidadRESUMEN
Recruitment of cells and mediators is altered during impaired wound healing, thereby delaying this process. To overcome this problem, the correlation of wound healing in older rats, and the impact of different molecular weight of hyaluronan without silver nanoparticles; (low-HA1), (High-HA2), (Medium- HA3) and with silver nanoparticles (High-HA4) is investigated. The superior HA were selected to be further investigated onto diabetic wounds. Our results pointed to a marked deficiency in wounds granulation in older rats, which was accompanied with impairment of healing process. In older rats group treated with HA2 or HA4, granulation and dermal construction were improved. Furthermore, the number of pathogenic bacteria on wounds was declined throughout the first 24h by HA2 and HA4. The wound size in HA4-treated older rats was significantly smaller than that in other HA1, HA2 or HA3-treated older ones. Also, diabetes impaired the level of inflammatory cytokine, in diabetic model. On contrary, HA4 was found to normalize the level of inflammatory cytokine, in the diabetic model. Furthermore, HA4 was found to recover all oxidative and toxicity markers in diabetic models. This data confirms the critical role of HA4 to improve granulation and inflammatory mediators in impaired older and diabetic rat wound healing.
Asunto(s)
Diabetes Mellitus Experimental/tratamiento farmacológico , Ácido Hialurónico/química , Inflamación/tratamiento farmacológico , Cicatrización de Heridas/efectos de los fármacos , Animales , Diabetes Mellitus Experimental/complicaciones , Diabetes Mellitus Experimental/microbiología , Diabetes Mellitus Experimental/patología , Humanos , Ácido Hialurónico/administración & dosificación , Inflamación/complicaciones , Inflamación/microbiología , Inflamación/patología , Nanopartículas del Metal/administración & dosificación , Nanopartículas del Metal/química , Peso Molecular , Ratas , Plata/administración & dosificación , Plata/químicaRESUMEN
Chitin and chitosan were obtained by chemical treatments of shrimp shells. Different particle sizes (50-1000 µm) of the raw material were used to study their effect on size distribution, demineralization, deproteinization and deacetylation of chitin and chitosan isolation process. The particle size in the range of 800-1000 µm was selected to isolate chitin, which was achieved by measuring nitrogen, protein, ash, and yield %. Hydrochloric acid (5%, v/v) was optimized in demineralization step to remove the minerals from the starting material. Aqueous solution of sodium hydroxide (5%, w/v) at 90 °C for (20 h) was used in deproteinization step to remove the protein. Pure chitin was consequently impregnated into high concentration of sodium hydroxide (50%) for 3.5 h at 90 °C to remove the acetyl groups in order to form high pure chitosan. The degree of deacetylation (DDA) of chitosan was controlled and evaluated by different analytical tools. The chemical structure of chitin and chitosan was confirmed by elemental analysis, ATR-FTIR, H/C NMR, XRD, SEM, UV-Vis spectroscopy, TGA, and acid-base titration. The isolated chitin and chitosan from shrimp shell showed excellent antibacterial activity against Gram (-ve) bacteria (Escherichia coli) comparing with commercial biopolymers.
Asunto(s)
Antibacterianos/farmacología , Quitosano/farmacología , Exoesqueleto/química , Animales , Antibacterianos/aislamiento & purificación , Océano Atlántico , Brasil , Quitina/aislamiento & purificación , Quitina/farmacología , Quitina/ultraestructura , Quitosano/aislamiento & purificación , Decápodos/química , Estabilidad de Medicamentos , Escherichia coli/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Difracción de Rayos XRESUMEN
Silver nanoparticles (Ag-NPs) have been successfully prepared with a simple and "green" chemical reduction method. Triple helical schizophyllan (SPG) was used for the first time as reducing and stabilizing agents. The effect of temperature, silver nitrate/schizophyllan concentrations, pH of the reactions medium and the reaction time were investigated. The obtained schizophyllan/Ag-NP was characterized by UV-vis spectroscopy, TEM, DLS, X-ray diffraction, TGA, and ATR-FTIR. The results revealed that, Ag-NPs attached to SPG through a strong non-covalent interaction, leading to good dispersion of Ag-NPs with a diameter of 6 nm within the biopolymer matrix. By increasing the pH of the reaction medium, the triple helical structure of SPG was partially broken. The SPG/AgNP nanocomposite was non-toxic for mouse fibroblast line (NIH-3T3) and human keratinocyte cell line (HaCaT).
Asunto(s)
Nanopartículas del Metal/toxicidad , Plata/química , Sizofirano/toxicidad , Animales , Línea Celular , Humanos , Concentración de Iones de Hidrógeno , Queratinocitos/efectos de los fármacos , Nanopartículas del Metal/química , Ratones , Microscopía Electrónica de Transmisión , Células 3T3 NIH , Sizofirano/química , Espectrofotometría Ultravioleta , Espectroscopía Infrarroja por Transformada de Fourier , Temperatura , Difracción de Rayos XRESUMEN
The present work aims to the development of innovative new derivatives of chitosan that can be used for medical applications. This innovation is based on the synthesis and characterization of chitosan-g-aminoanthracene derivatives. Thus, N-(anthracen-9-yl)-4,6-dichloro-[1,3,5]-triazin-2-amine (AT) reacted with chitosan by the following steps: at first, cyanuric chloride reacted with 9-aminoanthracene to obtain N-(anthracen-9-yl)-4,6-dichloro-[1,3,5]-triazin-2-amine (AT), then the AT reacted with chitosan to obtain (CH-g-AT). The final product of CH-g-AT was separated, purified and re-crystallized by dioxane. The structure of the prepared chitosan derivatives was confirmed by FTIR-ATR, solid-NMR, TGA, X-RD, and DSC. The new chitosan derivatives showed fluorescence spectra in liquid and in solid state as well. CH-g-AT showed also high antibacterial activity against gram -ve species (Escherichia coli).
Asunto(s)
Antibacterianos/síntesis química , Antibacterianos/farmacología , Quitosano/síntesis química , Quitosano/farmacología , Colorantes Fluorescentes/síntesis química , Colorantes Fluorescentes/farmacología , Antibacterianos/química , Técnicas de Química Sintética , Quitosano/química , Estabilidad de Medicamentos , Escherichia coli/efectos de los fármacos , Colorantes Fluorescentes/química , TemperaturaRESUMEN
Silver has been used since time immemorial in different chemical form to treat burns, wounds and several different infections caused by pathogenic bacteria, advancement of biological process of nanoparticles synthesis is evolving into a key area of nanotechnology. The current study deals with the green synthesis, characterization, and evaluation of the biological activity and cell viability of hyaluronan fibers with incorporated silver nanoparticles (HA-Ag NPs). Hyaluronan fiber was prepared by the dissolving of sodium hyaluronate (HA) in aqueous alkaline solution to prepare a transparent solution, which was used for the preparation of fibers by a wet-spinning technique. Consequently, hyaluronan fiber was used as capping and stabilizing agent for the preparation of fibers with silver nanoparticles. HA-Ag NPs were confirmed by transmission electron microscopy, dynamic light scattering, UV/VIS spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, thermal analysis, nuclear magnetic resonance, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. HA-Ag NPs showed high antibacterial activity of against Staphylococcus aureus and Escherichia coli. Cell viability tests indicated that hyaluronan, hyaluronan fibers and hyaluronan fibers with silver nanoparticles were non-toxic on the cell growth. Two different particles size of Ag NPs (10, 40 nm) had not any toxicity till the concentration limit. These tests were performed using mouse fibroblast cell line 3T3.
Asunto(s)
Antibacterianos/química , Antibacterianos/farmacología , Ácido Hialurónico/química , Ácido Hialurónico/farmacología , Nanopartículas del Metal/química , Plata/química , Células 3T3 , Animales , Antibacterianos/toxicidad , Supervivencia Celular/efectos de los fármacos , Escherichia coli/efectos de los fármacos , Ácido Hialurónico/toxicidad , Ratones , Tamaño de la Partícula , Solventes/química , Staphylococcus aureus/efectos de los fármacosRESUMEN
Multifinishing treatment of cotton fabrics was carried out using core-shell nanoparticles that consists of silver nanoparticles (Ag(0)) as core and chitosan-O-methoxy polyethylene glycol (CTS-O-MPEG) as shell. The synthesized (Ag(0)-CTS-O-MPEG) core-shell nanoparticle was applied to cotton fabrics using the conventional pad-dry-cure method. The finished fabrics were examined for their morphological features and surface characteristics by making use of scanning electron microscope (SEM-EDX), which reveals the well dispersion of (Ag(0)-CTS-O-MPEG) core-shell nanoparticles on cotton fabrics. Factors affecting the treatment such as core shell nanoparticles, citric acid (CA) concentration as well as curing temperature were studied. The treated fabrics, at optimum condition of 1% core shell nanoparticles, 5% citric acid, drying at 80°C, curing at 160°C for 2 min, showed excellent antibacterial activity against Gram-negative Escherichia coli (E. coli) and Gram-positive bacteria Staphylococcus aureus (S. aureus), even after 20 washing cycles in addition to an enhancement in crease recovery angles (CRA) along with a slight improvement in tensile strength (TS).
Asunto(s)
Fibra de Algodón , Nanopartículas del Metal/química , Antibacterianos , Quitosano/química , Nanopartículas del Metal/ultraestructura , Plata/química , TextilesRESUMEN
The application of green chemistry in the nano-science and technology is very important in the area of the preparation of various materials. In this work, an eco-friendly chemical method was successfully used for the preparation of hyaluronan fibers containing silver nanoparticles (AgNPs). Thus, hyaluronic acid (HA) was dissolved in an aqueous solution of sodium hydroxide to prepare a transparent solution, which was used for the preparation of fibers by a wet-spinning technique. Consequently, silver nanoparticles inside the fiber were prepared. Different parameters affecting the preparation of final product, such as concentration of silver nitrate, hyaluronan fiber concentration, time and temperature of the reaction, pH of the reaction mixture, were studied. AgNPs were confirmed by transmission electron microscopy (TEM), X-ray diffraction (XRD), two-dimensional X-ray scattering (2D SWAXS), UV/Vis spectroscopy, inductively coupled plasma optical emission spectrometry (ICP OES) and scan electron microscopy (SEM). Mechanical properties of prepared fibers were also measured.