A novel honey‐based nanofibrous scaffold for wound dressing application

In this study, nanofiber meshes were produced from aqueous mixtures of poly(vinyl alcohol) (PVA) and honey via electrospinning. The Electrospinning process was performed at different PVAs to honey ratios (100/0, 90/10, 80/20, 70/30, and 60/40). Dexamethasone sodium phosphate was selected as an anti‐inflammatory drug and incorporated in the electrospinning solutions. Its release behavior was determined. Uniform and smooth nanofibers were formed, independent of the honey content. In case honey content increased up to 40%, some spindle‐like beads on the fibers were observed. The diameter of electrospun fibers decreased as the ratio of honey increased. The release characteristics of the model drug from both the PVA and PVA/honey (80/20) nanofibrous mats were studied and statistical analysis was performed. All electrospun fibers exhibited a large initial burst release at a short time after incubation. The release profile was similar for both PVA and PVA/honey (80/20) drug‐loaded nanofibers. This study shows that an anti‐inflammatory drug can be released during the initial stages and honey can be used as a natural antibiotic to improve the wound dressing efficiency and increase the healing rate. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci, 2013     

Nano-curcumin/graphene platelets loaded on sodium alginate/polyvinyl alcohol fibers as potential wound dressing

Innovative composites of biopolymers and nanomaterials have been exploited to fabricate wound dressings which show functional abilities to improve different stages of wound healing by a variety of mechanisms. In this study, a polymeric nanocomposite dressing is fabricated by electrospinning of a blend of sodium alginate (SA), poly vinyl alcohol (PVA) and graphene nanoplatelets (Gnp). The crosslinking of the nanofibers is done by thermal treatment followed by ionic bonding of the fibers. The crosslinked fibers are loaded by curcumin, a natural potent anti-inflammatory compound, encapsulated in monomethoxy poly ethylene glycol-oleate micelles/polymersomes (NCur). Results indicate that by incorporation of Gnp and NCur into the SA/PVA scaffold the tensile strength is not changed (~7 MPa) but the elongation to break and toughness of the scaffolds significantly increase from 11.25±2.6 and 50.56 to 35.5±5.1% and 125.9 Jm^-3, respectively. The scaffolds support the controlled release of curcumin for 24 h in vitro. Biocompatibility of the scaffolds has been confirmed by cell viability assay on mouse fibroblast cells. Overall, the findings demonstrate the potential applications of the spun fibers for wound dressing purposes.     

Electrospun gelatin–arabinoxylan ferulate composite fibers for diabetic chronic wound dressing application

Blends of arabinoxylan ferulate (AXF) and gelatin (GEL) at 1:1, 2:1 and 4:1 mass ratios were electrospun into composite fibrous mats as a wound-healing drug delivery platform. The composite fibers were characterized in terms of morphology, tensile properties, pore size, porosity and molecular composition. The composite fibers showed excellent cytocompatibility. Silver was impregnated into GEL-AXF nanofibers, and it was slowly released, resulting in bacterial growth inhibition as confirmed by the Kirby–Bauer disk-diffusion assay. This work establishes an electrospun arabinoxylan fibrous material platform with the potential to treat chronic diabetic wounds.     

Fabrication of Chitosan/Silk Fibroin Composite Nanofibers for Wound-dressing Applications

Chitosan, a naturally occurring polysaccharide with abundant resources, has been extensively exploited for various biomedical applications, typically as wound dressings owing to its unique biocompatibility, good biodegradability and excellent antibacterial properties. In this work, composite nanofibrous membranes of chitosan (CS) and silk fibroin (SF) were successfully fabricated by electrospinning. The morphology of electrospun blend nanofibers was observed by scanning electron microscopy (SEM) and the fiber diameters decreased with the increasing percentage of chitosan. Further, the mechanical test illustrated that the addition of silk fibroin enhanced the mechanical properties of CS/SF nanofibers. The antibacterial activities against Escherichia coli (Gram negative) and Staphylococcus aureus (Gram positive) were evaluated by the turbidity measurement method; and results suggest that the antibacterial effect of composite nanofibers varied on the type of bacteria. Furthermore, the biocompatibility of murine fibroblast on as-prepared nanofibrous membranes was investigated by hematoxylin and eosin (H&E) staining and MTT assays in vitro, and the membranes were found to promote the cell attachment and proliferation. These results suggest that as-prepared chitosan/silk fibroin (CS/SF) composite nanofibrous membranes could be a promising candidate for wound healing applications.     

Fabrication and characterization of alginate/chitosan hydrogel combined with honey and aloe vera for wound dressing applications

Hydrogels can be one of the best polymeric wound dressings due to the desirable properties of wound healing. In this study, emphasizing the use of natural biomaterials such as Aloe vera and honey in the structure of cross-linked polymers, a novel hydrogel was produced that might be applied to healing wounds. In the beginning, four hydrogel groups were made from a combination of Sodium Alginate and Chitosan with Aloe vera extract and honey in optimum concentrations. Then the structure of those was evaluated by SEM and FTIR. After confirming hydrogels' structural properties, their physical properties, including swelling, porosity, density, mass loss, stability, and WVTR, were examined. Besides, the hydrogel biocompatibility was assessed by analyzing the cell viability and hemolytic activity. Adhesion of the cells to the hydrogel was also observed by SEM imaging. The results showed that the designed hydrogel has a porous structure with interconnected cavities, which their size can provide suitable conditions for cell adhesion, migration, and proliferation. Also, their physical and structural properties can be a strong suit to wound healing. Although honey's application can weaken the hydrogel structure, honey has beneficial properties due to its complex biomolecules. In contrast, Aloe vera in hydrogel generally improved the hydrogel's specificity for wound healing. According to the results of this study, taking advantage of hydrogels containing honey and Aloe vera based on alginate and chitosan polymers led to the formation of an acceptable structure and biocompatibility that can be used in future researches to repair tissues, especially wounds.     

Synthesis and characterization of polyvinyl alcohol/dextran/Zataria wound dressing with superior antibacterial and antioxidant properties

The aim of the present research was to synthesize and characterize polyvinyl alcohol/dextran/Zataria essential oil hydrogel wound dressings. For this purpose, dressings were made with different concentrations of polymers (PVA and Dex) and ZMO by solvent casting method. By dissolving PVA and Dextran in de-ionized water, PVA-Dex gel was made. The polymeric solution was mixed with glycerol. The pH of PVA-DEX-Glycerol solution was adjusted to 3 and glutaraldehyde was used as a cross-linker. ZMO, as the antibacterial and antioxidant agent, was added to the samples in different percentages (2,5,10%). It was found that both Dex and ZMO significantly influenced the hydrophilicity, gel fraction, and water uptake capacity of hydrogel films. The results showed that by the addition of Dex to PVA, the contact angle decreased from 48.54° ± 0.95 to 45.90 ± 0.73°, whereas by the addition of ZMO, the contact angle increased to 71.1 ± 2.43. SEM investigations revealed that the fabricated films had a uniform structure and the surface roughness increased with the addition of ZMO. The results indicated an increased elongation of 11.5% with the incorporation of ZMO into the films. The antimicrobial evaluation of the produced films showed that the loading of 10% v/v ZMO could broaden the microbicidal activity of PVA/Dex/ZMO film. The investigations on the interactions between synthesized wound dressings and fibroblast cells showed that the addition of ZMO into hydrogel films improved cell viability. The findings showed that PVA/Dex/ZMO films could have considerable use as wound dressing.     

Construction of a sandwich-type wound dressing with pain-reliever and pH-responsive antibiotic delivery system

A multifunctional sandwich type wound dressing was designed in which two types of microspheres, one to alleviate the pain (ibuprofen) and the other to protect the wound from infections (Gentamicin or Ciprofloxacin), were embedded into bilayer chitosan sponge. pH of the wound increases from acidic (pH ~ 5) to basic (pH ~ 8) via infection, so pH-dependent antibiotic release system was designed using gelatin B microspheres to respond to increasing pH. Ibuprofen release from chitosan microspheres, on the other hand, was pH-independent not to intervene with pain management in changing pH conditions. Crosslinking with glutaraldehyde (GA) affected both release profile and size distribution of microspheres and 2.5% GA was chosen to obtain pH-responsive gelatin microspheres with narrow size distribution (80% of microspheres in between 15 and 25 μm). The final system was found to be effective against both Staphylococcus aureus and Escherichia coli and changing pH seemed to affect the antimicrobial agent delivery as desired. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48252.     

Fabrication and characterization of a wound dressing composed of polyvinyl alcohol/nanochitosan/Artemisia ciniformis extract: An RSM study

This study reported the fabrication and characterization of an electrospun wound dressing composed of polyvinyl alcohol (PVA), nanochitosan (NC), and Artemisia ciniformis extract (AE). NC and AE wt% were defined as process parameters, and their effects on the diameter, mechanical properties, and cell attachment of the fibers were investigated using the Design Expert 7.0 software. The software provided quadratic equations, which were investigated statistically and graphically, confirmed that with the increase in the NC portion in the samples, the mechanical strength and fiber diameter increased. The increase is probably due to the proper dispersion of nanoparticle into a PVA matrix and the increased viscosity of the solution; however, cell viability showed an increasing/decreasing trend. The presence of AE lowered the mechanical properties of the samples while positively affecting cell viability. Furthermore, the samples had significant antibacterial properties against Escherichia coli as Gram-negative bacteria and Staphylococcus aureus as Gram-positive one, a notable property for wound dressings. Overall, our findings showed that PVA/NC/AE has an excellent potential for use in biomedical fields, particularly as a wound dressing.     

Preparation and characterization of ciprofloxacin‐loaded alginate/chitosan sponge as a wound dressing material

The aim of this study is preparation and characterization of alginate/chitosan sponges including a model antibiotic (i.e., ciprofloxacin) to use in wound and/or burn treatment. Sponges were prepared firstly by the gelation of sodium alginate followed by lyophilization, crosslinking with calcium chloride, and finally coating with chitosan. Sponges were characterized with respect to morphology, water uptake, in vitro drug release behavior, and antimicrobial activity. Investigated and evaluated parameters in all of these studies were selected as the concentration of calcium chloride, alginate viscosity, drug content, and molecular weight of chitosan. Drug release and water uptake were found to be greatly influenced by these parameters. Water uptake and drug release rate were decreased by increasing the crosslinking density, chitosan molecular weight, and alginate viscosity. In the antimicrobial tests, it was obtained that the antimicrobial activity is directly proportional with the release rates and water uptake. Morphological studies showed a highly porous structure with interconnected pores. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1602–1609, 2006     

Poly(L-lactide-co-caprolactone)/collagen electrospun mat: Potential for wound dressing and controlled drug delivery

Here we report a novel bioactive electrospun mat based on poly(L-lactide-co-caprolactone) (PLLC) and collagen for wound dressing and sustained drug delivery of gentamicin. PLLC/collagen electrospun mat loaded with 10% gentamicin showed bioactivity for 15 days against Gram-positive and Gram-negative bacteria. The in vitro cell culture of 3T3 fibroblasts confirmed that these electrospun mat provide an increased specific interface area and hydrophilicity to enhance cell attachment, proliferation, and migration. The modified PLLC/collagen mat provided an excellent enhancement in properties of antibacterial wound dressings with a minimum in vitro toxicity and high potency for promoting wound healing stages.     

Preparation of polyester nanofibers and nanofiber yarns from polyester/cellulose acetate butyrate immiscible polymer blends

Development of high throughput production processes for making thermoplastic nanofiber and nanofiber yarns are urgently needed. PET, PTT, and PBT nanofibers were prepared from PET/CAB, PTT/CAB, PBT/CAB immiscible polymer blends by in situ microfibrillar formation during the melt extruding process. The diameter distribution and crystallization properties of PET, PTT, and PBT nanofibers were analyzed. After removing the CAB matrix phase, the nanofibers could be collected in the forms of random or aligned nanofibers and nanofiber bundles or yarns. To understand the formation mechanism of the nanofibers, the morphology development of three different polyesters in the dispersed phase were studied with samples collected at different zones in a twin‐screw extruder. The morphological development mechanism of the dispersed phases involved the formation of sheets, holes and network structures, then the size reduction and formation of nanofibers. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Development of bacterial cellulose incorporating silk sericin,polyhexamethylene biguanide,and glycerin with enhanced physical properties and antibacterial activities for wound dressing application

Bacterial cellulose (BC) has been applied for wound dressing application. In this study, physical and biological properties of the BC dressing were improved by incorporation of silk sericin (SS), polyhexamethylene biguanide (PHMB), and glycerin. The glycerin incorporation reduced dehydration rate and wound adhesion of the BC dressing in a concentration-dependent manner. PHMB, an antiseptic agent, provided antibacterial activity against Gram-positive and Gram-negative bacteria. Meanwhile, SS would enhance collagen and tissue formation in wounds. Finally, we confirmed that the BC dressing incorporating SS, PHMB, and glycerin was safe to be used as a medical material according to ISO 10993-6 standard.     

Synergistic Effect of Co-Delivering Ciprofloxacin and Tetracycline Hydrochloride for Promoted Wound Healing by Utilizing Coaxial PCL/Gelatin Nanofiber Membrane

Combining multiple drugs or biologically active substances for wound healing could not only resist the formation of multidrug resistant pathogens, but also achieve better therapeutic effects. Herein, the hydrophobic fluoroquinolone antibiotic ciprofloxacin (CIP) and the hydrophilic broad-spectrum antibiotic tetracycline hydrochloride (TH) were introduced into the coaxial polycaprolactone/gelatin (PCL/GEL) nanofiber mat with CIP loaded into the PCL (core layer) and TH loaded into the GEL (shell layer), developing antibacterial wound dressing with the co-delivering of the two antibiotics (PCL-CIP/GEL-TH). The nanostructure, physical properties, drug release, antibacterial property, and in vitro cytotoxicity were investigated accordingly. The results revealed that the CIP shows a long-lasting release of five days, reaching the releasing rate of 80.71%, while the cumulative drug release of TH reached 83.51% with a rapid release behavior of 12 h. The in vitro antibacterial activity demonstrated that the coaxial nanofiber mesh possesses strong antibacterial activity against E. coli and S. aureus. In addition, the coaxial mats showed superior biocompatibility toward human skin fibroblast cells (hSFCs). This study indicates that the developed PCL-CIP/GEL-TH nanofiber membranes hold enormous potential as wound dressing materials.     

Synthesis and characterization of hydrogel‐silver nanoparticle‐curcumin composites for wound dressing and antibacterial application

Hydrogel silver nanocomposites are found to be excellent materials for antibacterial applications. To enhance their applicability novel hydrogel‐silver nanoparticle‐curcumin composites have been developed. For developing, these composites, the hydrogel matrices are synthesized first by polymerizing acrylamide in the presence of poly(vinyl sulfonic acid sodium salt) and a trifunctional crosslinker (2,4,6‐triallyloxy 1,3,5‐triazine, TA) using redox initiating system (ammonium persulphate/TMEDA). Silver nanoparticles are generated throughout the hydrogel networks using in situ method by incorporating the silver ions and subsequent reduction with sodium borohydride. Curcumin loading into hydrogel‐silver nanoparticles composite is achieved by diffusion mechanism. A series of hydrogel‐silver nanoparticle‐curcumin composites are developed and are characterized by using Fourier transform infrared (FTIR) and UV–visible (UV–vis) spectroscopy, X‐ray diffraction, thermal analyses, as well as scanning and transmission electron microscopic (SEM/TEM) methods. An interesting arrangement of silver nanoparticles i.e., a shining sun shape (ball) (～ 5 nm) with apparent smaller grown nanoparticles (～ 1 nm) is observed by TEM. The curcumin loading and release characteristics are performed for various hydrogel composite systems. A comparative antimicrobial study is performed for hydrogel‐silver nanocomposites and hydrogel‐silver nanoparticle‐curcumin composites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Surface modification of poly (ethylene terephthalate) fabric by soy protein isolate hydrogel for wound dressing application

In this study, a composite of poly (ethylene terephthalate) (PET) fabric and soy protein isolate (SPI) hydrogel loaded with gabapentin was developed. For covalent attachment of SPI on the surface of PET fabric, graft polymerization of acrylic acid (AA) on the surface of PET fabric was performed and then carboxyl groups available in the structure of AA were activated using EDAC and then SPI was coated on the surface of PET fabric. The results revealed appropriate connection between hydrogel and modified fabric. The hydrogel was characterized by swelling test and the drug release behavior was investigated. It was found that the casting temperature affects the swelling ratio of the hydrogel and an appropriate release profile of the drug was observed. The surface of fabric was characterized by contact angle measurement, electron microscopy, and infrared spectroscopy. In vitro cell culture study was performed using NIH 3T3 mouse fibroblasts to investigate the biocompatibility of final composite and MTS results along with morphology of cells on the surface of PET fabric coated with SPI revealed the biocompatibility of final product and no cell cytotoxicity was observed in modified PET fabric.     

A novel and facile impregnation-combustion fabrication of spherical CoAl2O4 supported on sepiolite nanofibers

In this study, sepiolite nanofibers-supported spherical CoAl₂O₄ composites were prepared by a novel and facile impregnation-combustion method, using nitrates and sepiolite minerals as the raw materials. The results showed that the optimal process for the nanocomposites formation was an impregnation step facilitated by stirring for 24?h at room temperature coupled with a calcination step performed at 300?℃ for 6?h. The characterizations by XRD, SEM and BET revealed that the CoAl₂O₄ particles were dispersed evenly on the surface of the sepiolite nanofibers with a complete crystal shape and uniform particle size, and the specific surface area has been improved significantly by adopting the sepiolite nanofibers as the support. Therefore, the sepiolite nanofibers-supported spherical CoAl₂O₄ composites with a good dispersion and suspension performance are a promising candidate in the fields of water-based coatings, heterogeneous catalytic reactions, ceramic materials, and so on.     

Molecular design,synthesis strategies and recent advances of hydrogels for wound dressing applications

With the changes in the modern disease spectrum, pressure ulcers, diabetic feet, and vascular-derived diseases caused refractory wounds is increasing rapidly. The development of wound dressings has partly improved the effect of wound management. However, traditional wound dressings can only cover the wound and block bacteria, but are generally powerless to recurrent wound infection and tissue healing. There is an urgent need to develop a new type of wound dressing with comprehensive performance to achieve multiple effects such as protecting the wound site from the external environment, absorbing wound exudate, anti-inflammatory, antibacterial, and accelerating wound healing process. Hydrogel wound dressings have the aforementioned characteristics, and can keep the wound in a moist environment because of the high water content, which is an ideal choice for wound treatment. This review introduces the wound healing process and the development and performance advantages of hydrogel wound dressings. The choice of different preparation materials gives the particularities of different hydrogel wound dressings. It also systematically explains the main physical and chemical crosslinking methods for hydrogel synthesis. Besides, in-depth discussion of four typical hydrogel wound dressings including double network hydrogels, nanocomposite hydrogels, drug-loaded hydrogels and smart hydrogels fully demonstrates the feasibility of developing hydrogels as wound dressing products and their future development trends.     

Development of antibacterial and morphological features of scaffolds based on polycaprolactone encapsulated with copper oxide/vanadium oxide for wound dressing applications

The development of highly effective dressing materials for human injuries that meet the complex requirements for clinical examination is still a challenge. In this regard, different biomaterials could be examined for wound dressing targets. Among these materials, polycaprolactone (PCL) is high biocompatible polymeric substance and has been used for numerous pharmaceutical applications. Furthermore, targeting antibacterial behavior could be done by merging additional nanoparticles such as copper oxide (CuO) and vanadium Oxide (V₂O₅). The scaffolds could be fabricated using the cast method, which is one of the most simple and facile methods. The morphological features and the surface roughness of the fabricated could be examined using X-ray diffraction, Raman spectroscopy, Fourier transform infrared (FTIR), and scanning electron microscopy (SEM) tests. The contact angle plays a significant role in studying the wettability of the scaffolds and the hydrophilic or hydrophobic behavior of the composed films. Besides the antibacterial behavior to evaluate the effectiveness of these scaffolds to protect the injury until the healing. The cell viability against human normal cells to examine the biocompatibility of the proposed compositions. In this regard, the topographical images show a smooth surface with random pores that have diameters in the range of 0.5–1.5 μm for pure PCL while, the porosity decreased with the addition of ginger and V₂O₅. The blend of CuO/V₂O₅/ginger@ PCL represents a noticeable increase in porosity with a diameter between 0.5 and 3 μm. The contact angles were recorded respectively at 55.02°, 54.12°, 53.89°, and 53.71° which refer to the tendency of the scaffolds to the hydrophilic behavior. In addition, the anti-bacterial activity of CuO/V₂O₅/ginger@PCL was represented with the diameter of the inhibition zone equal to 17.6±1.2 mm for E. coli and 12.3±1.2 mm for S. aureus.     

A novel synthesis method of nanostructured MgO-coated hollow carbon nanofibers via CO decomposition over Mg/MgO catalyst

An easy and one-step synthesis method for preparation of oxide-coated carbon nanofibers (CNFs) by Mg/MgO catalyst has been reported. For this purpose, the mixture of Mg (metal) and MgO (fused magnesia) powders were heat treated at 1000 °C under reducing atmosphere of CO gas and the final product was comprehensively characterized by various analytical methods such as X-ray diffractometry, field emission scanning electron microscopy (FE-SEM), transition electron microscopy (TEM) and Raman spectroscopy. The results showed the formation of hollow CNFs with the average diameter and wall thickness of 100 nm and 25 nm, respectively. Furthermore, SEM micrographs have obviously revealed the presence of highly packed MgO nanoparticles (with average particle size of 30 nm) on the outer surface of fibers owing to catalytic reaction of Mg _(v) and CO gasses. Considering the superior physical properties of the synthesized oxide-coated material such as great packing, high uniformity as well as the absence of structural defects, oxide-coated CNFs showed considerable enhancement in the oxidation resistance compared to the conventional carbon nanofibers. The synthesized oxide coated CNFs showed a weight loss of less than 5 wt% after exposing to high temperature at oxidative atmosphere highlighting the significant effect of the oxide coating. This effect was confirmed by a thermoanalytical technique using differential scanning calorimeter equipped with the online gas analyzer.     

A novel wound dressing composed of nonwoven fabric coated with chitosan and herbal extract membrane for wound healing

This study presents a novel design of an easily stripped bilayer composite that consists of an upper layer of soybean protein nonwoven fabric coated with a lower layer, genipin‐crosslinked chitosan and Bletilla striata herbal extract (GCB) film as a wound dressing material (GCB/NWF). Preliminary tests investigated the in vitro characteristics of the genipin‐crosslinked chitosan (GC) film. Experimental results showed that the dark bluish color of the GC film may have resulted from the reaction of genipin with the amino acid group in the chitosan solution. Additionally, adding more wt% genipin caused the bluish color of the GC films to be darker. This new wound dressing material also exhibited good mechanical properties. Genipin and chitosan were released from the soaked GC film. Cytotoxic test revealed that 20 ppm of the genipin in the culture medium could be criteria, over which cytotoxicity to L929 fibroblasts could be produced. However, the chitosan and B. striata herbal extract not only were not toxic but also promoted the viability and growth of L929 fibroblasts. Additionally, the GCB film more effectively supported cell attachment and growth. The in vivo histological assessment results revealed that epithelialization and reconstruction of the wound were achieved by covering the wound with the GCB/NWF wound dressing material, and it would be easily stripped from the wound surface without damaging newly regenerated tissue. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers