The potential of alginate/carboxymethyl cellulose based thin films was demonstrated as a testing platform for evaluation of the influence of in situ incorporated growth factors into formulations ...intended for 3D bio-printed wound healing materials. Actual formation of blend films with and without included growth factors was analysed using ATR-IR spectroscopy. Surface morphology and topography were evaluated by atomic force and scanning electron microscopies, whereas the hydrophilicity of all tested materials was determined using the water contact angle measurement method. The inclusion of growth factors into blend films did not affect the films' formation, nor their morphology, whereas their highly hydrophilic character was even slightly enhanced by the added growth factors. Further, several aspects (viability, proliferation and cell morphology), in regard to the blend films included growth factors' influence on both of the most abundant skin cell types (keratynocytes and fibroblasts) were tested. A significantly improved cell viability was detected for films with incorporated growth factors. The prepared thin film-based testing platform could present an important tool to aid the development of novel printable (bio)inks.
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•Thin films can be an important model platform for development of advanced products.•Inclusion of Growth Factors into thin films does not affect the morphological properties.•EGF in thin films significantly improves the viability of keratinocytes.•Alginate/CMC thin films with FGF stimulate the viability of skin fibroblasts.
A review of herbal medicines in wound healing Maver, Tina; Maver, Uroš; Stana Kleinschek, Karin ...
International journal of dermatology,
07/2015, Volume:
54, Issue:
7
Journal Article
Peer reviewed
Herbs have been integral to both traditional and non‐traditional forms of medicine dating back at least 5000 years. The enduring popularity of herbal medicines may be explained by the perception that ...herbs cause minimal unwanted side effects. More recently, scientists increasingly rely on modern scientific methods and evidence‐based medicine to prove efficacy of herbal medicines and focus on better understanding of mechanisms of their action. However, information concerning quantitative human health benefits of herbal medicines is still rare or dispersed, limiting their proper valuation. Preparations from traditional medicinal plants are often used for wound healing purposes covering a broad area of different skin‐related diseases. Herbal medicines in wound management involve disinfection, debridement, and provision of a suitable environment for aiding the natural course of healing. Here we report on 22 plants used as wound healing agents in traditional medicine around the world. The aim of this review is therefore to review herbal medicines, which pose great potential for effective treatment of minor wounds.
Electrospinning as method for fabrication of wound dressing materials with included medical plant extracts for wound treatment has lately gained increasing attention. However, the transfer of ...nanofiber fabrication with included plant extracts from the research to the pilot and industrial scale production, using needleless electrospinning is a vital area of research, which could enable its large-scale commercial exploitation. Carboxymethyl cellulose (CMC) is a cheap, water soluble biopolymer, and in blends with the spinning agent polyethylene oxide (PEO) it is a suitable polymer for a large-scale nanofiber production. Thus, this study addresses the needleless electrospinning of CMC/PEO/plant extract blend aqueous solutions in order to fabricate cellulose based wound dressing material, suitable for treatment of acute wounds. The influence of plant extracts on the morphology of the electrospun mats was further evaluated. The antioxidant and antibacterial properties of the as-prepared electrospun mats were determined, where special attention was devoted to the stability/degradation study of phenolic compounds in plant extracts during the electrospinning process. This research was complemented by the release study and cell viability testing with results indicating a promising potential of this product to use for wound care as a self-contained wound dressing or as a part of number of already existing novel wound dressing materials.
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3D printed bioscaffolds from polysaccharide materials hold a huge promise in tissue engineering applications, especially in regard to in vitro culturing of pancreatic cells, which require cell-ECM ...mimicking interactions in all spatial dimensions to remain viable for longer times. Material features, surface characteristics and the physical nature of scaffolds at multiple scales (e.g., macro-porosity, micro-topography) should be tailored to mimic crucial aspects of native or pathologically transformed tissues. With this in mind, we prepared hybrid hydrogel formulations from commonly used materials (alginate, carboxymethyl cellulose, nanofibrillated cellulose) and optimized them for 3D printing. With the intention to fine-tune their printability, rheological, mechanical, swelling, degradation and surface properties, variable concentrations of NiCu nanoparticles were incorporated into the mentioned hydrogels. We showed that NiCu nanoparticles might provide an effective tool for controlling hydrogel viscosity and scaffold swelling, degradation and surface properties. All scaffolds also promoted cell adhering, cell aggregation, cell migration and support long-term growth of pancreatic cells, which also displayed a physiologically more relevant morphology. This study lays the groundwork for development of novel 3D printed bioscaffolds with tailorable properties with the purpose to recapitulate characteristics of native tissues more closely.
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•Formulations from alginate, carboxymethyl cellulose, nanofibrillated cellulose and their optimization for 3D printing.•Added NiCu NPs tailored the formulation printability, rheology, mechanical, swelling, degradation and surface properties.•NiCu NPs are highly effective for controlling hydrogel properties leading to tailorable final scaffold characteristics.•Scaffolds promoted cell adhering, cell aggregation, cell migration and support long-term growth of pancreatic cells.•Study lays the groundwork for development of novel 3D printed bioscaffolds with tailorable properties.
Limitations in wound management have prompted scientists to introduce bioprinting techniques for creating constructs that can address clinical problems. The bioprinting approach is renowned for its ...ability to spatially control the three-dimensional (3D) placement of cells, molecules, and biomaterials. These features provide new possibilities to enhance homology to native skin and improve functional outcomes. However, for the clinical value, the development of hydrogel bioink with refined printability and bioactive properties is needed. In this study, we combined the outstanding viscoelastic behavior of nanofibrillated cellulose (NFC) with the fast cross-linking ability of alginate (ALG), carboxymethyl cellulose (CMC), and encapsulated human-derived skin fibroblasts (hSF) to create a bioink for the 3D bioprinting of a dermis layer. The shear thinning behavior of hSF-laden bioink enables construction of 3D scaffolds with high cell density and homogeneous cell distribution. The obtained results demonstrated that hSF-laden bioink supports cellular activity of hSF (up to 29 days) while offering proper printability in a biologically relevant 3D environment, making it a promising tool for skin tissue engineering and drug testing applications.
•Sulphated and aminated celluloses form stable mixed-charge complexes on polycaprolactone.•Dry and wet masses of coatings can be measured by QCM-D.•Charge complexes strongly reduce albumin ...binding.•Amino cellulose coatings and charge complexes retard fibrin clot formation.
This study describes the formation of cellulose based polyelectrolyte charge complexes on the surface of biodegradable polycaprolactone (PCL) thin films. Anionic sulphated cellulose (CS) and protonated cationic amino cellulose (AC) were used to form these complexes with a layer-by-layer coating technique. Both polyelectrolytes were analyzed by charge titration methods to elucidate their pH-value dependent protonation behavior. A quartz crystal microbalance with dissipation (QCM-D) in combination with X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) were used to follow the growth, stability and water content of up to three AC/CS bi-layers in aqueous environment. This was combined with coagulation studies on one, two and three bilayers of AC/CS, measuring the thrombin formation rate and the total coagulation time of citrated blood plasma with QCM-D. Stable mixed charged bilayers could be prepared on PCL and significantly higher masses of AC than of CS were present in these complexes. Strong hydration due to the presence of ammonium and sulphate substituents on the backbone of cellulose led to a significant BSA repellent character of three bilayers of AC/CS coatings. The total plasma coagulation time was increased in comparison to neat PCL, indicating an anticoagulative nature of the coatings. Surprisingly, a coating solely composed of an AC layer significantly prolonged the total coagulation time on the surfaces although it did not prevent fibrinogen deposition. It is suggested that these cellulose derivative-based coatings can therefore be used to prevent unwanted BSA deposition and fibrin clot formation on PCL to foster its biomedical application.
Despite the extensive utilization of polysaccharide hydrogels in regenerative medicine, current fabrication methods fail to produce mechanically stable scaffolds using only hydrogels. The recently ...developed hybrid extrusion-based bioprinting process promises to resolve these current issues by facilitating the simultaneous printing of stiff thermoplastic polymers and softer hydrogels at different temperatures. Using layer-by-layer deposition, mechanically advantageous scaffolds can be produced by integrating the softer hydrogel matrix into a stiffer synthetic framework. This work demonstrates the fabrication of hybrid hydrogel-thermoplastic polymer scaffolds with tunable structural and chemical properties for applications in tissue engineering and regenerative medicine. Through an alternating deposition of polycaprolactone and alginate/carboxymethylcellulose gel strands, scaffolds with the desired architecture (e.g., filament thickness, pore size, macro-/microporosity), and rheological characteristics (e.g., swelling capacity, degradation rate, and wettability) were prepared. The hybrid fabrication approach allows the fine-tuning of wettability (approx. 50-75°), swelling (approx. 0-20× increased mass), degradability (approx. 2-30+ days), and mechanical strength (approx. 0.2-11 MPa) in the range between pure hydrogels and pure thermoplastic polymers, while providing a gradient of surface properties and good biocompatibility. The controlled degradability and permeability of the hydrogel component may also enable controlled drug delivery. Our work shows that the novel hybrid hydrogel-thermoplastic scaffolds with adjustable characteristics have immense potential for tissue engineering and can serve as templates for developing novel wound dressings.
Polysaccharides are excellent network formers and are often processed into films from water solutions. Despite being hydrophilic polysaccharides, the typical xylans liberated from wood are sparsely ...soluble in water. We have previously suggested that an additional piece to the solubilization puzzle is modification of the xylan backbone via oxidative cleavage of the saccharide ring. Here, we demonstrate the influence of the degree of modification, i.e., degree of oxidation (DO) on xylan solubilization and consequent film formation and stability. Oxidized and reduced wood xylans (i.e., dialcohol xylans) with the highest DO (77 %) within the series exhibited the smallest hydrodynamic diameter (dh) of 60 nm in dimethylsulfoxide (DMSO). We transferred the modified xylans into films credit to their established solubility and then quantified the film water interactions. Dialcohol xylans with intermediate DOs (42 and 63 %) did not form continuous films. The films swelled slightly when subjected to humidity. However, the film with the highest DO demonstrated a significant moisture uptake that depended on the film mass and was not observed with the other modified grades or with unmodified xylan.
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Stable chitosan thin films can be promising substrates for creating nanometric peptide-bound polyglucosamine layers. Those are of scientific interest since they can have certain structural ...similarities to bacterial peptidoglycans. Such films were deposited by spin coating from chitosan solutions and modified by acetylation and N-protected amino acids. The masses of deposited materials and their stability in aqueous solutions at different pH values and water interaction were determined with a quartz crystal microbalance with dissipation (QCM-D). The evolution of the surface composition was followed by X-ray photoelectron (XPS) and attenuated total reflectance infrared (ATR-IR) spectroscopy. Morphological changes were measured by atomic force microscopy (AFM), while the surface wettability was monitored by by static water contact angle measurements. The combination of the characterization techniques enabled an insight into the surface chemistry for each treatment step and confirmed the acetylation and coupling of N-protected glycine peptides. The developed procedures are seen as first steps toward preparing thin layers of acetylated chitin, potentially imitating the nanometric peptide substituted glycan layers found in bacterial cell walls.
This work concerns freeze-dry processing of CNF aerogels, including aluminum hydroxide trihidrate (Alolt) particles and Sodium silicate, as active and passive flame retardants, respectively. ...Alkalinity of Sodium silicate promotes stability, dissociation and co-precipitation of Al(OH)
3
component onto CNFs. The (auto)fluorescence-enabled confocal microscopy enabled visualization of anisotropic microstructure with open and closed-cell segments, depicting the Alolt as single and aggregated particles. Low thermal conduction (~ 0.045 W/mK) was estimated, irrespective of composition, while Alolt was found to reduce (by 30%) the aerogel moisture content. Sodium silicate promotes char formation as passive action, reducing the evolution of gaseous species, while burning test shows complete flame retardation through active endothermic reaction assigned to Alolt. Additive combinations did not amplify, nor diminish, the flame retardant effect of particular component, yet affected positively the elastic modulus. Considering simple “green” processing, low additive load, and high insulation and flame retardant efficiency, these aerogels hold promise as thermal insulation materials.
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