Silver Sulfadiazine Encapsulated Polycaprolactone‐Zein Hybrid Nanofibers as a Wound Dressing

In this report a novel antibacterial wound dressing was prepared and then characterized for required testing. We loaded silver sulfadiazine (AgSD) for the first time by electrospinning. AgSD was added in zein (0.3%, 0.4%, 0.5%, and 0.6% by weight) and was electrospun to fabricate nanofiber mats for wound dressings. Nanofiber mats were characterized by Fourier transform infrared spectroscopy (FTIR) to check if there was any chemical reaction between AgSD and zein. Morphological properties were analyzed by Scanning Electron Microscopy (SEM), which showed uniform nanofibers without any bead formation. The diameter of the nanofibers gradually decreased with an increase in the amount of AgSD, which can be associated with strong physical bonding between zein and AgSD. Thermal properties of nanofiber mats were analyzed by Thermogravimetric Analysis (TGA). X-Ray Diffraction (XRD) further demonstrated the crystalline structure of the nanofiber mats, and X-ray Photoelectron spectroscopy (XPS) was performed to confirm Ag and S contents in the prepared wound dressings. In order to investigate antibacterial properties, a disc diffusion method was employed. Bacillus and E. coli bacteria strains were used as Gram-positive and Gram-negative strains respectively. The antibacterial effectiveness of AgSD released from zein nanofibers was determined from the zone inhibition of the bacteria. The antibacterial activity of zein nanofibers loaded with drug was observed with both strains of bacteria in comparison to a control. Excellent antibacterial efficacy was attributed to the sample with 0.6% AgSD. Excellent release properties were also associated with the sample with 0.6% AgSD in zein nanofibers. Keeping in mind the abovementioned characteristics, prepared nanofiber mats would be effective for application in wound dressings.

Silver sulfadiazine-loaded electrospun ethyl cellulose/polylactic acid/collagen nanofibrous mats with antibacterial properties for wound healing

Objective The objective of this study was to synthesize and characterize inorganic zirconium oxide (ZrO2), organic [bisphenol A diglycidyl ether dimethacrylate (Bis-GMA)+triethylene glycol dimethacrylate (TEGDMA)+polyethylene glycol dimethacrylate (PEGDMA)] and hybrid (ZrO2+ Bis-GMA + TEGDMA) nanofibers and the use of these nanofibers for improving flexural strength (FS) and flexural modulus (FM), fracture toughness (FT) and impact strength (IS) of polymethyl methacrylate (PMMA) resin. Materials and methods Inorganic, organic and hybrid nanofibers were synthesized by wet electrospinning technique. The study was divided into four groups according to the type of added nanofibers (6%) to the heat-curing PMMA denture base resin; control group: PMMA without nanofibers, inorganic group: PMMA with silanized ZrO2 nanofibers, organic group: PMMA with Bis-GMA/TEGDMA/PEGDMA nanofibers and hybrid group: PMMA with ZrO2/Bis-GMA/TEGDMA nanofibers. According to ISO FDIS 20795-1:2013, three-point bending test was used to measure FS, FM and FT for each group (n = 10). According to ISO 197-A1: 2005, impact tester was used to measure IS for each group (n = 10). One-way analysis of variance was used for statistical significance between groups and post-hoc (Tukey's test) was used for multiple comparisons. P value less than or equal to 0.01 was considered significantly different. Results The synthesized pure forms of three types of nanofibers were characterized by scanning electron microscope and Fourier transform infrared spectroscopy. Nanofibers-reinforced groups (ZrO2, hybrid and organic, respectively) recorded high means % than that of the control group as follows: 205, 184 and 170% for FS (MPa), 184, 149 and 120% for FM (GPa), 210, 189 and 177% for FT (MPa m1/2) and 151, 180 and 176% for IS (KJ/m2). In each of the four tested mechanical properties, one-way analysis of variance revealed a significant differences between the studied groups (P = 0.000) and post-hoc (Tukey's test) revealed that nanofibers-reinforced groups were markedly significantly higher than control group (P = 0.000). Conclusion ZrO2, Bis-GMA/TEGDMA/PTEGDMA and ZrO2/Bis-GM/TEGDMA hybrid nanofibers synthesized by electrospinning technique improved significantly FS, FM, FT and IS of PMMA resin (P = 000).

The use of herbal drugs as biocompatible and nontoxic drugs without special side effects in wound dressings are highly favored compared to that of chemical and synthetic drugs. In this study, the properties and performance of electrospun poly(ε‐caprolactone) (PCL), poly(lactic acid) (PLA), and their 50/50 hybrid nanofibrous mats containing the herbal drug thymol (1.2% v/v) as wound dressings were investigated. The optimized solution concentrations of PCL (12% w/v) and PLA (3% w/v) in chloroform/dimethylformamide (7:3) for electrospinning were determined with viscometry and scanning electron microscopy studies to obtain smooth and beadless nanofibers. The results of the drug‐release behavior along with swelling tests showed that the electrospun 50/50 PCL/PLA hybrid nanofibers had the highest level of drug release (∼ 72%) compared with the PCL and PLA nanofibrous samples. The release kinetics of thymol from PCL, PLA, and 50/50 PCL/PLA hybrid nanofibrous mats were studied by the Peppas equation and the zero‐order, first‐order, Higuchi, and Hixon–Crowell models. Antibacterial evaluations showed that the electrospun 50/50 PCL/PLA hybrid nanofibrous samples containing thymol had satisfactory effects on Staphylococcus aureus compared with Escherichia coli bacteria during the treatment periods. In vivo rat wound‐healing and histological performance observations of thymol‐loaded 50/50 PCL/PLA nanofibrous mats, the commercial wound dressing Comfeel Plus, and gauze bandages (control) after 14‐day post‐treatment periods were evaluated. The results reveal that the electrospun 50/50 PCL/PLA hybrid nanofibers containing thymol had a remarkable wound‐closure percentage of about 92.5% after a period of 14 days. Finally, the crystallinity and thermal behavior of the electrospun 50/50 PCL/PLA hybrid nanofibrous mats with and without thymol were studied by differential scanning calorimetry. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

The management of chronic wounds is challenging. The factors that impede wound healing include malnutrition, diseases (such as diabetes, cancer), and bacterial infection. Most of the presently utilized wound dressing materials suffer from severe limitations, including poor antibacterial and mechanical properties. Wound dressings formulated from the combination of biopolymers and synthetic polymers (i.e., poly (vinyl alcohol) or poly (ε-caprolactone) display interesting properties, including good biocompatibility, improved biodegradation, good mechanical properties and antimicrobial effects, promote tissue regeneration, etc. Formulation of these wound dressings via electrospinning technique is cost-effective, useful for uniform and continuous nanofibers with controllable pore structure, high porosity, excellent swelling capacity, good gaseous exchange, excellent cellular adhesion, and show a good capability to provide moisture and warmth environment for the accelerated wound healing process. Based on the above-mentioned outstanding properties of nanofibers and the unique properties of hybrid wound dressings prepared from poly (vinyl alcohol) and poly (ε-caprolactone), this review reports the in vitro and in vivo outcomes of the reported hybrid nanofibers.

BackgroundSilver, incorporation with natural or synthetic polymers, has been used as an effective antibacterial agent since decades. Silver has potential applications in healthcare especially in nanoparticles form but silver sulfadiazine (AgSD) is the most efficient antibacterial agent especially for burn wound dressings.MethodIn this report, mechanical, structural, and antibacterial properties of PAN nanofibers incorporation with silver sulfadiazine are mainly focused. AgSD was loaded for the first time on electrospinning as well as self-synthesized AgSD on PAN nanofibers by solution immersion method and then compared the results of both.ResultsOccurrence of chemical reaction among the functional groups of AgSD and PAN were analyzed using FTIR, for both types of specimen. Morphological and surface properties of prepared nanofiber mats were characterized by scanning electron microscope, and it resulted in uniform nanofibers without bead formation. Diameter of nanofibers was slightly increased with addition of AgSD by in situ and immersion methods respectively. Nanoparticles distribution was analyzed by transmission electron microscopy. Thermal properties were analyzed by thermo-gravimetric analyzer and it was observed that AgSD decreased thermal stability of PAN which is better from biomedical perspective. X-ray diffraction declared crystalline structure of nanofiber mats. Presence of Ag and S contents in nanofiber mats was analyzed by X-ray photo spectroscopy. Antibacterial properties of nanofiber mats were investigated by disc diffusion method was carried out. E. coli and Bacillus bacteria strain were used as gram-negative and gram-positive respectively. Zone inhibition of the bacteria was used as a tool to determine effectiveness of AgSD released from PAN nanofiber mats. The antibacterial properties of PAN nanofibers impregnated with AgSD were determined with both types of bacteria strains to compare with control one.ConclusionOn the basis of characterization results it is concluded that PAN/AgSD (immersion) nanofiber mats have better structural and antibacterial properties than that of PAN/AgSD (in situ) nanofiber mats. So, from our point of view, self-synthesized AgSD is recommended for further production of nanofiber mats for antibacterial applications.

Anti-oxidant enriched hybrid nanofibers: Effect on mechanical stability and biocompatibility

Electrospun chitosan (CTS) nanofibers have been well known for use as a wound dressing in the biomedical field. Nevertheless, fatal bacterial infections are still a serious problem when CTS nanofibers are used for wound treatment. In this study, we designed a novel wound dressing based on blending the chitosan with polyurethane (CTS/PU) containing silver sulfadiazine (AgSD) in order to enhance both antibacterial activity and mechanical strength. This fiber sheet was produced using the electrospinning (ELSP) technique. The CTS/PU containing AgSD fiber sheet was characterized by energy-dispersive X-ray spectroscopy (EDX). The physicochemical properties of the CTS/PU/AgSD fiber sheets were also characterized by thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FT-IR). The electrospun fibers were morphologically characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). For an in vitro evaluation, the CTS/PU/AgSD fiber sheets were tested for their antibacterial activity against gram-negative Pseudomonas aeruginosa (P. aeruginosa), gram-positive Staphylococcus aureus (S. aureus) and Methicillin-resistant Staphylococcus aureus (MRSA). The results indicate that CTS/PU/AgSD fiber sheets have strong antimicrobial activity as displayed by inhibition of bacterial growth and prevention of infection during the healing process. These results indicate that this material would be good for use as a wound dressing material.

Objective Fabrication of an antibiotic-loaded scaffold with controlled release properties for wound dressing is one oftissue engineering challenges. The aim of this study was to evaluate the wound-healing effectiveness of 500-µm thickpolycaprolactone (PCL) nanofibrous mat containing silver sulfadiazine (SSD) as an antibacterial agent.Materials and Methods In this experimental study, an electrospun membrane of PCL nanofibrous mat containing 0.3%weight SSD with 500 µm thickness, was prepared. Morphological and thermomechanical characteristics of nanofiberswere evaluated. Drug content and drug release properties as well as the surface hydrophobicity of the nanofibrousmembrane were determined. Antimicrobial properties and cellular viability of the scaffold were also examined. A fullthickness wound of 400 mm2 was created in rats, to evaluate the wound-healing effects of PCL/SSD blend in comparisonwith PCL and vaseline gas used as the control group.Results SSD at a concentration of 0.3% improved physicochemical properties of PCL. This concentration of SSD didnot inhibit the attachment of human dermal fibroblasts (HDFs) to nanofibers in vitro, but showed antibacterial activityagainst Gram-positive Staphylococcus aureus (ST) and Gram-negative Pseudomonas aeruginosa (PS). Overall,results showed that SSD improves characteristics of PCL nanofibrous film and improves wound-healing process inone-week earlier compared to control.ConclusionCytotoxicity of SSD in fabricated nanofibrous mat is a critical challenge in designing an effective wounddressing that neutralizes cellular toxicity and improves antimicrobial activity. The PCL/SSD nanofibrous membrane with 500-µm thickness and 0.3% (w/v) SSD showed applicable characteristics as a wound dressing and it accelerated wound healingprocess in vivo.

Electrospinning polyurethane has been utilized as skin wound dressing for protecting skin wounds from infection and thus facilitating their healings, but also limited by its imperfect biocompatibility, mechanical and antibacterial properties. This paper presents our study on the addition of graphene oxide to electrospinning polyurethane for improved properties, as well as its in vitro characterization. Polyurethane/graphene oxide wound dressing was electrospun with varying amount of graphene oxide (from 0.0% to 2.0%); and in vitro tests was carried out to characterize the wound dressing properties and performance from the structural, mechanical, and biological perspectives. Scanning electron microscopy and Fourier-transform infrared spectroscopy were used to confirm the interaction between graphene oxide particles and polyurethane fibers, while the scanning electron microscopy images further illustrated that the wound dressing was of a porous structure with fibre diameters depending on the amount of graphene oxide added; specifically, 20 to 180 nm were for composite polyurethane/graphene oxide fibers and 600 to 900 nm for pure polyurethane. Our results also revealed that the hydrophilicity and swelling properties of the wound dressing could be regulated by the amount of graphene oxide added to the polyurethane/graphene oxide composites. Mechanical, antibacterial, and cytotoxicity properties of the composite polyurethane/graphene oxide wound dressing were examined with the results illustrating that the addition of graphene oxide could improve the properties of the electrospun wound dressing. Combined together, our study illustrates that electrospinning polyurethane/graphene oxide composite is promising as skin wound dressing.

Fabrication and characterization of PVA/Gum tragacanth/PCL hybrid nanofibrous scaffolds for skin substitutes

Optimal Aloe vera encapsulated PCL/Gel nanofiber design for skin substitute application and the evaluation of its in vivo implantation

Possibility of wound dressing using poly(l-leucine)/poly(ethylene glycol)/poly(l-leucine) triblock copolymer

Wound dressings play a crucial role in promoting wound healing by providing a protective barrier against infections and facilitating tissue regeneration. Electrospun nanofibers have emerged as promising materials for wound dressing applications due to their high surface area, porosity, and resemblance to the extracellular matrix. In this study, chitosan, a biocompatible and biodegradable polymer, was electrospun into nanofibers for potential use in wound dressing. The chitosan nanofibers were characterized by using various analytical techniques to assess their morphology and biocompatibility. Scanning electron microscopy (SEM) revealed the formation of uniform and bead-free nanofibers with diameters ranging from tens to hundreds of nanometers. Structural analysis, including Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD), elucidated the chemical composition and crystalline structure of the nanofibers. Furthermore, in vitro studies evaluated the cytocompatibility of the chitosan nanofibers with human dermal fibroblasts, demonstrating cell viability and proliferation on the nanofibers. Additionally, antibacterial properties were assessed to evaluate the potential of chitosan nanofibers in preventing wound infections. Overall, the characterization results highlight the promising attributes of electrospun chitosan nanofibers as wound dressings, paving the way for further investigation and development in the field of advanced wound care. This study has been carried out for the first time in our region and has assessed the antibacterial properties of electrospun chitosan nanofiber material. The created mat has shown efficaciousness against bacteria that are both gram-positive and gram-negative.

Silk fibroin nanofibers containing chondroitin sulfate and silver sulfadiazine for wound healing treatment