Eugenol micro-emulsion reinforced with silver nanocomposite electrospun mats for wound dressing strategies

Design and Evaluation of Microemulsion-Based Drug Delivery Systems for Biofilm-Based Infection in Burns

Normal skin is the first line of defense in the human body. A burn injury makes the skin susceptible to bacterial infection, thereby delaying wound healing and ultimately leading to sepsis. The chances of biofilm formation are high in burn wounds due to the presence of avascular necrotic tissue. The most common pathogen to cause burn infection and biofilm is Pseudomonas aeruginosa. The purpose of this study was to create a microemulsion (ME) formulation for topical application to treat bacterial burn infection. In the present study, tea tree oil was used as the oil phase, Tween 80 and transcutol were used as surfactants, and water served as the aqueous phase. Pseudo ternary phase diagrams were used to determine the design space. The ranges of components as suggested by the design were chosen, optimization of the microemulsion was performed, and in vitro drug release was assessed. Based on the characterization studies performed, it was found that the microemulsion were formulated properly, and the particle size obtained was within the desired microemulsion range of 10 to 300 nm. The I release study showed that the microemulsion followed an immediate release profile. The formulation was further tested based on its ability to inhibit biofilm formation and bacterial growth. The prepared microemulsion was capable of inhibiting biofilm formation.

Evaluation of the wound healing efficacy of new antibacterial polymeric nanofiber based on polyethylene oxide coated with copper nanoparticles and defensin peptide: An in-vitro to in-vivo assessment

Objective

Today, designing nanofibers with antibacterial properties using electrospinning technology is one of the attractive approaches for wound healing.

Methods

& analysis: This study aims to fabricate a nanocomposite from polyethylene oxide (PEO) coated with copper nanoparticles (NPs) and defensin peptide with wound healing and antimicrobial properties in different ratios of CuNPs/defensin (2/0 mg), (1.5/0.5 mg), and (1/1 mg) in the fixed contain polymer (98 mg). Then, the nanofiber properties were investigated by SEM, tensile, DSC, and BET analysis. Also, the antibacterial properties against S. aureus and E. coli, antioxidant, and in-vivo wound healing effects and histological analysis of the designed nanocomposites were evaluated in rat models.

Results

Our SEM images showed that CuNPs and defensin were properly coated on the PEO surface. According to the tensile, DSC, and antibacterial analysis results, the most appropriate feature was related to CuNPs/defensin (1.5/0.5 mg), with maximum elasticity, heat resistance, and antibacterial activity. Furthermore, the designed nanocomposites showed the best performance as a wound closure agent by increasing dermis and epidermis volume density, stimulating fibroblast cells and collagen fiber production, and improving skin vessels.

Conclusion

According to our results, PEO nanofibers loaded with CuNPs and defensin have the best potential for wound healing, and they can be used as antibacterial materials in the textile, drug, and medical industries.

Wound Dressing Based on Silver Nanoparticle Embedded Wool Keratin Electrospun Nanofibers Deposited on Cotton Fabric: Preparation, Characterization, Antimicrobial Activity, and Cytocompatibility

Wool keratin (WK) protein is attractive for wound dressing and biomedical applications due to its excellent biodegradability, cytocompatibility, and wound-healing properties. In this work, WK-based wound dressings were prepared by depositing WK/poly(vinyl alcohol) (PVA) and silver nanoparticle (Ag NP)-embedded WK/PVA composite nanofibrous membranes on cotton fabrics by electrospinning. Ag NPs were biosynthesized by reduction and stabilization with sodium alginate. The formed Ag NPs were characterized by ultraviolet-visible and Fourier transform infrared (FTIR) spectroscopy, and their size was determined by transmission electron microscopy and image analysis. The formed Ag NPs were spherical and had an average diameter of 9.95 nm. The produced Ag NP-embedded WK/PVA composite nanofiber-deposited cotton fabric surface was characterized by FTIR and dynamic contact angle measurements, and the nanofiber morphologies were characterized by scanning electron microscopy. The average diameter of the nanofibers formed by 0.1% Ag NP-embedded WK/PVA solution was 146.7 nm. The antibacterial activity of the surface of cotton fabrics coated with electrospun composite nanofibers was evaluated against the two most common wound-causing pathogens, Staphylococcus aureus and Pseudomonas aeruginosa. The cotton fabric coated with 0.1% Ag NP-embedded WK/PVA nanofibers showed very good antibacterial activity against both pathogens, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay results showed good cytocompatibility against L-929 mouse fibroblast cells. However, the increase in Ag NP content in the nanofibers to 0.2% negatively affected the cell viability due to the high release rate of Ag ions. The results achieved show that the developed wound dressing has good potential for wound healing applications.

Anti-Biofilm Strategies: A Focused Review on Innovative Approaches

Biofilm (BF) can give rise to systemic infections, prolonged hospitalization times, and, in the worst case, death. This review aims to provide an overview of recent strategies for the prevention and destruction of pathogenic BFs. First, the main phases of the life cycle of BF and maturation will be described to identify potential targets for anti-BF approaches. Then, an approach acting on bacterial adhesion, quorum sensing (QS), and the extracellular polymeric substance (EPS) matrix will be introduced and discussed. Finally, bacteriophage-mediated strategies will be presented as innovative approaches against BF inhibition/destruction.

In Situ Preparation of Dehydrodieugenol-Loaded Silver Nanoparticles and their Antischistosomal Activity

Schistosomiasis is a major neglected disease that imposes a substantial worldwide health burden, affecting approximately 250 million people globally. As praziquantel is the only available drug to treat schistosomiasis, there is a critical need to identify new anthelmintic compounds, particularly from natural sources. To enhance the activity of different natural products, one potential avenue involves its combination with silver nanoparticles (AgNP). Based on this approach, a one-step green method for the in situ preparation of dehydrodieugenol (DHDG) by oxidation coupling reaction using silver and natural eugenol is presented. AgNP formation was confirmed by UV-Vis spectroscopy due to the appearance of the surface plasmon resonance (SPR) band at 430 nm which is characteristic of silver nanoparticles. The nanoparticles were spherical with sizes in the range of 40 to 50 nm. Bioassays demonstrated that the silver nanoparticles loaded with DHDG exhibited significant anthelmintic activity against Schistosoma mansoni adult worms without toxicity to mammalian cells and an in vivo animal model (Caenorhabditis elegans), contributing to the development of new prototypes based on natural products for the treatment of schistosomiasis.

Emulsion electrospinning of zein nanofibers with carotenoid microemulsion: Optimization, characterization and fortification

In this study, carotenoid microemulsion was encapsulated in zein nanofibers via emulsion electrospinning. Optimization study was applied to determine optimum parameters by response surface methodology. The voltage, flow rate and distance as optimum conditions were determined as 23 kV, 1.7 mL/h and 12.75 cm, respectively. Lycopene, β-carotene, encapsulation efficiency, encapsulation yield and zeta potential of zein nanofibers in optimum conditions were estimated as 4.054 mg/kg, 0.649 mg/kg, 77.78%, 41.76% and -29.73 mV, respectively. The addition of microemulsion affected nanofibers diameter and morphologies. Diffusion coefficient of zein nanofibers decreased with addition of microemulsion under optimum conditions. The electrospinning improved thermal stability of microemulsion. The carotenoid microemulsion could be entrapped into the zein fibers according to ATR-FTIR spectrum. Model foods were fortificated with zein nanofibers. The addition of nanofibers changed color of the foods during the storage. Carotenoid compounds were more stable in nanofibers followed by olive oil, milk and water.

Eugenol-Based Polymeric Materials-Antibacterial Activity and Applications

Eugenol (4-Allyl-2-methoxy phenol) (EUG) is a plant-derived allyl chain-substituted guaiacol, widely known for its antimicrobial and anesthetic properties, as well as the ability to scavenge reactive oxygen species. It is typically used as a mixture with zinc oxide (ZOE) for the preparation of restorative tooth fillings and treatment of root canal infections. However, the high volatility of this insoluble-in-water component of natural essential oils can be an obstacle to its wider application. Moreover, molecular eugenol can be allergenic and even toxic if taken orally in high doses for long periods of time. Therefore, a growing interest in eugenol loading in polymeric materials (including the encapsulation of molecular eugenol and polymerization of EUG-derived monomers) has been noted recently. Such active macromolecular systems enhance the stability of eugenol action and potentially provide prolonged contact with pathogens without the undesired side effects of free EUG. In this review, we present an overview of methods leading to the formation of macromolecular derivatives of eugenol as well as the latest developments and further perspectives in their pharmacological and antimicrobial applications.

Nanomaterials and Coatings for Managing Antibiotic-Resistant Biofilms

Biofilms are a global health concern responsible for 65 to 80% of the total number of acute and persistent nosocomial infections, which lead to prolonged hospitalization and a huge economic burden to the healthcare systems. Biofilms are organized assemblages of surface-bound cells, which are enclosed in a self-produced extracellular polymer matrix (EPM) of polysaccharides, nucleic acids, lipids, and proteins. The EPM holds the pathogens together and provides a functional environment, enabling adhesion to living and non-living surfaces, mechanical stability, next to enhanced tolerance to host immune responses and conventional antibiotics compared to free-floating cells. Furthermore, the close proximity of cells in biofilms facilitates the horizontal transfer of genes, which is responsible for the development of antibiotic resistance. Given the growing number and impact of resistant bacteria, there is an urgent need to design novel strategies in order to outsmart bacterial evolutionary mechanisms. Antibiotic-free approaches that attenuate virulence through interruption of quorum sensing, prevent adhesion via EPM degradation, or kill pathogens by novel mechanisms that are less likely to cause resistance have gained considerable attention in the war against biofilm infections. Thereby, nanoformulation offers significant advantages due to the enhanced antibacterial efficacy and better penetration into the biofilm compared to bulk therapeutics of the same composition. This review highlights the latest developments in the field of nanoformulated quorum-quenching actives, antiadhesives, and bactericides, and their use as colloid suspensions and coatings on medical devices to reduce the incidence of biofilm-related infections.

A review on contemporary nanomaterial-based therapeutics for the treatment of diabetic foot ulcers (DFUs) with special reference to the Indian scenario

Diabetes mellitus (DM) is a predominant chronic metabolic syndrome, resulting in various complications and high mortality associated with diabetic foot ulcers (DFUs). Approximately 15-30% of diabetic patients suffer from DFUs, which is expected to increase annually. The major challenges in treating DFUs are associated with wound infections, alterations to inflammatory responses, angiogenesis and lack of extracellular matrix (ECM) components. Furthermore, the lack of targeted therapy and efficient wound dressings for diabetic wounds often results in extended hospitalization and limb amputations. Hence, it is essential to develop and improve DFU-specific therapies. Nanomaterial-based innovative approaches have tremendous potential for preventing and treating wound infections of bacterial origin. They have greater benefits compared to traditional wound dressing approaches. In this approach, the physiochemical features of nanomaterials allow researchers to employ different methods for diabetic wound healing applications. In this review, the status and prevalence of diabetes mellitus (DM) and amputations due to DFUs in India, the pathophysiology of DFUs and their complications are discussed. Additionally, nanomaterial-based approaches such as the use of nanoemulsions, nanoparticles, nanoliposomes and nanofibers for the treatment of DFUs are studied. Besides, emerging therapeutics such as bioengineered skin substitutes and nanomaterial-based innovative approaches such as antibacterial hyperthermia therapy and gene therapy for the treatment of DFUs are highlighted. The present nanomaterial-based techniques provide a strong base for future therapeutic approaches for skin regeneration strategies in the treatment of diabetic wounds.

Multi-antibacterial agent-based electrospun polycaprolactone for active wound dressing

Today, due to the greater knowledge of the side effects of chemical drugs and the favorable pharmacological properties of herbal compounds, the use of these compounds is increasing. Since wounds need fast and efficient healing, wound dressing fabrication methods play an important role in wound healing. In this research, electrospinning process was used to prepare samples. Natural antibacterial compounds, such as curcumin, piperine, eugenol, and rutin were loaded in electrospun nano-fibrous based on polycaprolactone. Three-component novel systems of curcumin-piperine-eugenol (PCPiEu), and curcumin-piperine-rutin (PCPiR) were designed and prepared. Their synergistic effect was investigated and also compared with one- and two-component systems. The results showed that medium diameter nanofibers of PCPiEu and PCPiR samples was 198.38 and 142.60, respectively, and they were obtained in smooth, uniform and bead free morphology using optimization of process parameters. The amount of water absorption and water vapor permeability of the three-component samples were in the appropriate range (8.33-10.42 mg cm² h^-1) for wound dressings. The mechanical properties of samples were reduced compared to the control sample, which required further investigation. Antibacterial tests showed good results for partial toxicity of PCPiEu and PCPiR samples. Antibacterial tests showed minor toxicity in PCPiR samples and good results were obtained for PCPiEu samples. In addition, the results showed that PCPiEu and PCPiR samples exhibited antibacterial activity against Gram-positive bacterium Staphylococcus aureus and Gram-negative Enterococcus faecalis bacterium, so that killing ability of 74% and 75% against Gram-positive bacterium and 99.47% and 96.88% against Gram-negative bacterium were obtained for these three systems, respectively.