Electrospun nanofibers for wound healing

Electrospinning/3D printing drug-loaded antibacterial polycaprolactone nanofiber/sodium alginate-gelatin hydrogel bilayer scaffold for skin wound repair

Skin injuries and defects, as a common clinical issue, still cannot be perfectly repaired at present, particularly large-scale and infected skin defects. Therefore, in this work, a drug-loaded bilayer skin scaffold was developed for repairing full-thickness skin defects. Briefly, amoxicillin (AMX) was loaded on polycaprolactone (PCL) nanofiber via electrospinning to form the antibacterial nanofiber membrane (PCL-AMX) as the outer layer of scaffold to mimic epidermis. To maintain wound wettability and promote wound healing, external human epidermal growth factor (rhEGF) was loaded in sodium alginate-gelatin to form the hydrogel structure (SG-rhEGF) via 3D printing as inner layer of scaffold to mimic dermis. AMX and rhEGF were successfully loaded into the scaffold. The scaffold exhibited excellent physicochemical properties, with elongation at break and tensile modulus were 102.09 ± 6.74% and 206.83 ± 32.10 kPa, respectively; the outer layer was hydrophobic (WCA was 112.09 ± 4.67°), while the inner layer was hydrophilic (WCA was 48.87 ± 5.52°). Meanwhile, the scaffold showed excellent drug release and antibacterial characteristics. In vitro and in vivo studies indicated that the fabricated scaffold could enhance cell adhesion and proliferation, and promote skin wound healing, with favorable biocompatibility and great potential for skin regeneration and clinical application.

Bakuchiol nanoemulsion loaded electrospun nanofibers for the treatment of burn wounds

The present work aims to develop and evaluate the wound healing potential of bakuchiol nanoemulsion loaded electrospun scaffolds. Since oxidative stress and microbial burden leads the burn wounds to become chronic and fatal to patients, a phytoconstituent, bakuchiol (BAK), was screened on the basis of antioxidant and antimicrobial potential which also defined its dose. Furthermore, BAK was incorporated into a nanoemulsion to enhance its therapeutic efficacy, reduce its dosage frequency, and maximize its stability. The present study is inclined towards the collaborative interaction of natural products and novel drug delivery systems to develop safe and therapeutically efficient systems for burn wound healing. The optimized nanoemulsion showed excellent antioxidant and antimicrobial potential against wound susceptible pathogens, i.e., Candida albicans and Methicillin-resistant Staphylococcus aureus which was further loaded into gelatin based hydrogel and nanofibrous scaffold system. The mesh structure of scaffolds was chosen as a suitable carrier system for wound healing process not only because it offers resemblance to skin's anatomy but is also capable of providing uniform distribution of wound biomarkers across the skin. The prepared nanofibers were assessed for their analgesic, anti-inflammatory, and wound healing potential which was observed to be significantly better than its gel formulation.

The urchin-like gold nanoparticles/poly(ε-caprolactone)/chitosan electrospun nanofibers for antibacterial active packaging

Inspired by the natural antimicrobial effect of the topographical features of insect wings, this study prepared urchin-like gold nanoparticles (UGNPs) and deposited them on poly(ε-caprolactone) (PCL)/chitosan (P/C) electrospun nanofiber film to strengthen antibacterial activities of this active packaging. Results showed that L-Dopa was a suitable reducing agent to prepare UGNPs, and the spine length of UGNPs increased from 21.23 to 35.83 nm as the molar ratio of L-Dopa:HAuCl4 increased from 1 to 3. As the nanofiber film was immersed in the nanoparticle solution for a longer time, the UGNP content in P/C nanofibers increased. As the spine length of UGNPs and depositing UGNP content increased, the inhibition rate against S. aureus and E. coli. of P/C nanofiber film increased. In addition, P/C nanofiber film deposited with UGNPs also exhibited good thermal stability, hydrophilicity, mechanical strength, and water vapor permeability, exhibiting its potential as an antibacterial active packaging.

Wound Healing Promotion via Release of Therapeutic Metallic Ions from Phosphate Glass Fibers: An In Vitro and Ex Vivo Study

Biomaterials capable of promoting wound healing and preventing infections remain in great demand to address the global unmet need for the treatment of chronic wounds. Phosphate-based glasses (PG) have shown potential as bioresorbable materials capable of inducing tissue regeneration, while being replaced by regenerated tissue and releasing therapeutic species. In this work, phosphate-glass-based fibers (PGF) in the system P2O5-CaO-Na2O added with 1, 2, 4, 6, and 10 mol % of the therapeutic metallic ions (TMI) Ag+, Zn2+, and Fe3+ were manufactured via electrospinning of coacervate gels. Coacervation is a sustainable, cost-effective, water-based method to produce PG. All TMI are effective in promoting wound closure (re-epithelialization) in living human skin ex vivo, where the best-performing system is PGF containing Ag+. In particular, PGF with ≥4 mol % of Ag+ is capable of promoting 84% wound closure over 48 h. These results are confirmed by scratch test migration assays, with the PGF-Ag systems containing ≥6 mol % of Ag+, demonstrating significant wound closure enhancement (up to 72%) after 24 h. The PGF-Ag systems are also the most effective in terms of antibacterial activity against both the Gram-positive Staphylococcus aureus and the Gram-negative Escherichia coli. PGF doped with Zn2+ shows antibacterial activity only against S. aureus in the systems containing Zn2+ ≥ 10 mol %. In addition, PGF doped with Fe3+ rapidly accelerates ex vivo healing in patient chronic wound skin (>30% in 48 h), demonstrating the utility of doped PGF as a potential therapeutic strategy to treat chronic wounds.

Characterization of Electrospinning Chitosan Nanofibers Used for Wound Dressing

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.

Polymer-Based Wound Dressings Loaded with Essential Oil for the Treatment of Wounds: A Review

Wound healing can result in complex problems, and discovering an effective method to improve the healing process is essential. Polymeric biomaterials have structures similar to those identified in the extracellular matrix of the tissue to be regenerated and also avoid chronic inflammation, and immunological reactions. To obtain smart and effective dressings, bioactive agents, such as essential oils, are also used to promote a wide range of biological properties, which can accelerate the healing process. Therefore, we intend to explore advances in the potential for applying hybrid materials in wound healing. For this, fifty scientific articles dated from 2010 to 2023 were investigated using the Web of Science, Scopus, Science Direct, and PubMed databases. The principles of the healing process, use of polymers, type and properties of essential oils and processing techniques, and characteristics of dressings were identified. Thus, the plants Syzygium romanticum or Eugenia caryophyllata, Origanum vulgare, and Cinnamomum zeylanicum present prospects for application in clinical trials due to their proven effects on wound healing and reducing the incidence of inflammatory cells in the site of injury. The antimicrobial effect of essential oils is mainly due to polyphenols and terpenes such as eugenol, cinnamaldehyde, carvacrol, and thymol.

Extraction of γ-chitosan from insects and fabrication of PVA/γ-chitosan/kaolin nanofiber wound dressings with hemostatic properties

A nanofiber-based composite nonwoven fabric was fabricated for hemostatic wound dressing, integrating polyvinyl alcohol (PVA), kaolin, and γ-chitosan extracted from three type of insects. The γ-chitosan extracted from Protaetia brevitarsis seulensis exhibited the highest yield at 21.5%, and demonstrated the highest moisture-binding capacity at 535.6%. In the fabrication process of PVA/kaolin/γ-chitosan nonwoven fabrics, an electrospinning technique with needle-less and mobile spinneret was utilized, producing nanofibers with average diameters ranging from 172 to 277 nm. The PVA/kaolin/γ-chitosan nonwoven fabrics demonstrated enhanced biocompatibility, with cell survival rates under certain compositions reaching up to 86.9% (compared to 74.2% for PVA). Furthermore, the optimized fabric compositions reduced blood coagulation time by approximately 2.5-fold compared to PVA alone, highlighting their efficacy in hemostasis. In other words, the produced PVA/kaolin/γ-chitosan nonwoven fabrics offer potential applications as hemostatic wound dressings with excellent biocompatibility and improved hemostatic performance.

3D-printed electrospun fibres for wound healing

Wound management for acute and chronic wounds has become a serious clinical problem worldwide, placing considerable pressure on public health systems. Owing to the high-precision, adjustable pore structure, and repeatable manufacturing process, 3D-printed electrospun fibre (3DP-ESF) has attracted widespread attention for fabricating wound dressing. In addition, in comparison with 2D electrospun fibre membranes fabricated by traditional electrospinning, the 3D structures provide additional guidance on cell behaviour. In this perspective article, we first summarise the basic manufacturing principles and methods to fabricate 3DP-ESF. Then, we discuss the function of 3DP-ESF in manipulating the different stages of wound healing, including anti-bacteria, anti-inflammation, and promotion of cell migration and proliferation, as well as the construction of tissue-engineered scaffolds. In the end, we provide the current challenge faced by 3DP-ESF in the application of skin wound regeneration and its promising future directions.

GO/AgNW aided sustained release of ciprofloxacin loaded in Starch/PVA nanocomposite mats for wound dressings application

Compared to conventional bandages, which do not meet all wound care requirements, nanofiber wound dressings could provide a potentially excellent environment for healing. In the present research, nanocomposite membrane based on starch (St) - polyvinyl alcohol (PVA) nanofibers containing ciprofloxacin antibiotic drug loaded on graphene oxide‑silver nanowire (GO-AgNWs) hybrid nanoparticles is produced by electrospinning process. Morphological studies showed that the length and diameter of silver nanowires are 21 ± 9.17 μm and 82 ± 10.52 nm, respectively. The contact angle of 57.1° due to the hydrophilic nature of nanofibers, also the swelling degree of 679.51 % and, the water vapor permeability of 2627 ± 56 (g/m2.day) can be expressed as a confirmation of the ability of this wound dressing to manage secretions around the wound. In evaluating the antibacterial activity of these nanocomposite membranes against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus bacteria, the most potent antibacterial effect is in the case of nanofibers containing a high percentage of starch and nanoparticles carrying ciprofloxacin; with non-growth halos of 47.58 mm and 22.06 mm was recorded. The release of ciprofloxacin drug in vitro was reported to be 61.69 % during 24 h, and the final release rate was 82.17 %. Despite the biocompatibility and cell viability of 97.74 % and the biodegradability rate of 28.51 %, the StP-GOAgNWCip nanocomposite membrane can be introduced as a suitable candidate for wound dressing.

New dimensions of electrospun nanofiber material designs for biotechnological uses

Electrospinning technology has garnered wide attention over the past few decades in various biomedical applications including drug delivery, cell therapy, and tissue engineering. This technology can create nanofibers with tunable fiber diameters and functionalities. However, the 2D membrane nature of the nanofibers, as well as the rigidity and low porosity of electrospun fibers, lower their efficacy in tissue repair and regeneration. Recently, new avenues have been explored to resolve the challenges associated with 2D electrospun nanofiber membranes. This review discusses recent trends in creating different electrospun nanofiber microstructures from 2D nanofiber membranes by using various post-processing methods, as well as their biotechnological applications.

Application of Deferoxamine in Tissue Regeneration Attributed to Promoted Angiogenesis

Deferoxamine, an iron chelator used to treat diseases caused by excess iron, has had a Food and Drug Administration-approved status for many years. A large number of studies have confirmed that deferoxamine can reduce inflammatory response and promote angiogenesis. Blood vessels play a crucial role in sustaining vital life by facilitating the delivery of immune cells, oxygen, and nutrients, as well as eliminating waste products generated during cellular metabolism. Dysfunction in blood vessels may contribute significantly to the development of life-threatening diseases. Anti-angiogenesis therapy and pro-angiogenesis/angiogenesis strategies have been frequently recommended for various diseases. Herein, we describe the mechanism by which deferoxamine promotes angiogenesis and summarize its application in chronic wounds, bone repair, and diseases of the respiratory system. Furthermore, we discuss the drug delivery system of deferoxamine for treating various diseases, providing constructive ideas and inspiration for the development of new treatment strategies.

Precise healing of oral and maxillofacial wounds: tissue engineering strategies and their associated mechanisms

Precise healing of wounds in the oral and maxillofacial regions is usually achieved by targeting the entire healing process. The rich blood circulation in the oral and maxillofacial regions promotes the rapid healing of wounds through the action of various growth factors. Correspondingly, their tissue engineering can aid in preventing wound infections, accelerate angiogenesis, and enhance the proliferation and migration of tissue cells during wound healing. Recent years, have witnessed an increase in the number of researchers focusing on tissue engineering, particularly for precise wound healing. In this context, hydrogels, which possess a soft viscoelastic nature and demonstrate exceptional biocompatibility and biodegradability, have emerged as the current research hotspot. Additionally, nanofibers, films, and foam sponges have been explored as some of the most viable materials for wound healing, with noted advantages and drawbacks. Accordingly, future research is highly likely to explore the application of these materials harboring enhanced mechanical properties, reduced susceptibility to external mechanical disturbances, and commendable water absorption and non-expansion attributes, for superior wound healing.

Silk fibroin-based dressings with antibacterial and anti-inflammatory properties

Silk fibroin is a fibrillar protein obtained from arthropods such as mulberry and non-mulberry silkworms. Silk fibroin has been used as a dressing in wound treatment for its physical, chemical, mechanical, and biological properties. This systematic review analyzed studies from PubMed, Web of Science, and Scopus databases to identify the molecules preferred for functionalizing silk fibroin-based dressings and to describe their mechanisms of exhibiting anti-inflammatory and antibacterial properties. The analysis of the selected articles allowed us to classify the dressings into different conformations, such as membranes, films, hydrogels, sponges, and bioadhesives. The incorporation of various molecules, including antibiotics, natural products, peptides, nanocomposites, nanoparticles, secondary metabolites, growth factors, and cytokines, has allowed the development of dressings that promote wound healing with antibacterial and immunomodulatory properties. In addition, silk fibroin-based dressings have been established to have the potential to regenerate wounds such as venous ulcers, arterial ulcers, diabetic foot, third-degree burns, and neoplastic ulcers. Evaluation of the efficacy of silk fibroin-based dressings in tissue engineering is an area of great activity that has shown significant advances in recent years.

Trends in the Incorporation of Antiseptics into Natural Polymer-Based Nanofibrous Mats

Nanofibrous materials represent a very promising form of advanced carrier systems that can be used industrially, especially in regenerative medicine as highly functional bandages, or advanced wound dressings. By incorporation of antimicrobial additives directly into the structure of the nanofiber carrier, the functionality of the layer is upgraded, depending on the final requirement-bactericidal, bacteriostatic, antiseptic, or a generally antimicrobial effect. Such highly functional nanofibrous layers can be prepared mostly by electrospinning technology from both synthetic and natural polymers. The presence of a natural polymer in the composition is very advantageous. Especially in medical applications where, due to the presence of the material close to the human body, the healing process is more efficient and without the occurrence of an unwanted inflammatory response. However, converting natural polymers into nanofibrous form, with a homogeneously distributed and stable additive, is a great challenge. Thus, a combination of natural and synthetic materials is often used. This review clearly summarizes the issue of the incorporation and effectiveness of different types of antimicrobial substances, such as nanoparticles, antibiotics, common antiseptics, or substances of natural origin, into electrospun nanofibrous layers made of mostly natural polymer materials. A section describing the problematic aspects of antimicrobial polymers is also included.

Electrospinning technologies for the delivery of Biopharmaceuticals: Current status and future trends

This review provides an in-depth exploration of electrospinning techniques employed to produce micro- or nanofibres of biopharmaceuticals using polymeric solutions or melts with high-voltage electricity. Distinct from prior reviews, the current work narrows its focus on the recent developments and advanced applications in biopharmaceutical formulations. It begins with an overview of electrospinning principles, covering both solution and melt modes. Various methods for incorporating biopharmaceuticals into electrospun fibres, such as surface adsorption, blending, emulsion, co-axial, and high-throughput electrospinning, are elaborated. The review also surveys a wide array of biopharmaceuticals formulated through electrospinning, thereby identifying both opportunities and challenges in this emerging field. Moreover, it outlines the analytical techniques for characterizing electrospun fibres and discusses the legal and regulatory requirements for their production. This work aims to offer valuable insights into the evolving realm of electrospun biopharmaceutical delivery systems.

Innovative Electrospun Nanofiber Mats Based on Polylactic Acid Composited with Silver Nanoparticles for Medical Applications

Nanofibers are some of the most attractive materials that can modify functionalities for developing new kinds of specific applications and are mainly used as a biomedical material. Herein, we designed and prepared antibacterial nonwoven fiber mats of PLA and PLA composited with Ag nanoparticles by electrospinning. The effects of varying filler contents on their chemical, surface morphology, thermal, water absorbency, and antibacterial properties were investigated using FTIR, SEM/EDS, DSC, swelling ratio, and qualitative and quantitative antibacterial tests. FTIR and EDS spectra indicated that Ag nanoparticles were incorporated in the PLA without chemical bonding. SEM revealed that the average diameter of the PLA nanofibers containing the Ag nanoparticles was more significant than those without those particles. In addition, fiber diameters are proportional to the amount of Ag nanoparticle contents. DSC indicated that the Ag nanoparticles can be incorporated within the PLA matrix without strongly affecting their thermal properties. Moreover, the crystallinity of the composite nonwoven fiber mats was higher than those of fiber mats in the neat PLA. However, TGA revealed that the loaded Ag can improve the thermal stability of the PLA electrospun fiber mats. Accordingly, the antibacterial activities revealed that all the composite nanofiber mats exhibited excellent resistance against S. aureus and E. coli bacterial strains. In addition, in the cell toxicity study, all produced hybrids of nonwoven fiber mats induced a reduction in cell viability for the L929 fibroblast cells. Our results suggest that the designed and prepared nonwoven fiber mats may have good potential for use in the biomedical field, particularly in wound dressing applications.

Modeling and optimization of poly(lactic acid)/poly(ℇ-caprolactone)/Nigella sativa extract nanofibers production for skin wounds healing by artificial neural network and response surface methodology models

Electrospun fibrous scaffolds have great potential for the effective treatment of wounds. Novel blend scaffolds were fabricated from poly(ℇ- caprolactone) (PCL)/poly (lactic acid) (PLA) with Nigella sativa (NS) extract in different concentrations of 10 %, 15 %, 20 %, and 25 % by one nozzle electrospinning. RSM and ANN models were used to determine optimal nanofiber. The results showed that the ANN model had average goodness values of almost 1.992 which was higher than the RSM model with an amount of 1.823. The best sample was determined with the combination of parameters such as PLA/PCL (70:29) concentration, voltage 17 kV, and flow rate 0.2 ml/h in diameter of nanofiber 410 nm by Genetic Algorithm (GA) model with cost value 0.0216 that was lower than cost value (0.0927) of ANN model. The effect of NS extract on nanofibers properties showed that loading high concentrations of NS extract in PLA/PCL polymer solutions caused a decrease in nanofibers diameter, hydrophilicity, and tensile strength. Overall, PLA/PCL/NS 25 % nanofiber was selected as an optimal web with an average diameter of 370 ± 68 nm with a young modulus 5.94 MPa. This scaffold also exhibited the highest antibacterial activity, cell attachment, and cell viability based on the MTT assay.

The effect of κ-carrageenan and ursolic acid on the physicochemical properties of the electrospun nanofibrous mat for biomedical application

Wound dressing materials such as nanofiber (NF) mats have gained a lot of attention in recent years owing to their wonderful effect on accelerating the healing process and protection of wounds. In this regard, three different types of NF mats were fabricated using pure polyvinylpyrrolidone (PVP), PVP/κ-carrageenan (KG), and ursolic acid (UA) in the optimal PVP/KG ratio by electrospinning method to apply them as wound dressings. The morphology, chemical structure, degradation, porosity, mechanical properties and antioxidant activity of the produced NFs were investigated. Moreover, cell studies (e.g., cell proliferation, adhesion, and migration) and their antibacterial properties were evaluated. Adding KG and UA reduced the mean diameter size of the PVP-based NFs to ∼98 nm in the optimal sample, with defect-free morphology. The PVP/KG/UA 0.25 % exhibited the highest porosity, hydrophilicity, and degradation rate and a wound closure rate of 60 %, 2.5 times higher than that of the control group. Furthermore, this sample's proliferation and antibacterial ability were significantly higher than the other groups. These findings confirmed that the produced UA-loaded NFs have excellent properties as wound dressing.

Cerium oxide nanoparticles: Synthesis methods and applications in wound healing

Wound care and treatment can be critical from a clinical standpoint. While different strategies for the management and treatment of skin wounds have been developed, the limitations inherent in the current approaches necessitate the development of more effective alternative strategies. Advances in tissue engineering have resulted in the development of novel promising approaches for accelerating wound healing. The use of various biomaterials capable of accelerating the regeneration of damaged tissue is critical in tissue engineering. In this regard, cerium oxide nanoparticles (CeO2 NPs) have recently received much attention because of their excellent biological properties, such as antibacterial, anti-inflammatory, antioxidant, and angiogenic features. The incorporation of CeO2 NPs into various polymer-based scaffolds developed for wound healing applications has led to accelerated wound healing due to the presence of CeO2 NPs. This paper discusses the structure and functions of the skin, the wound healing process, different methods for the synthesis of CeO2 NPs, the biological properties of CeO2 NPs, the role of CeO2 NPs in wound healing, the use of scaffolds containing CeO2 NPs for wound healing applications, and the potential toxicity of CeO2 NPs.

Recent Progress in Stimuli-Responsive Antimicrobial Electrospun Nanofibers

Electrospun nanofibrous membranes have garnered significant attention in antimicrobial applications, owing to their intricate three-dimensional network that confers an interconnected porous structure, high specific surface area, and tunable physicochemical properties, as well as their notable capacity for loading and sustained release of antimicrobial agents. Tailoring polymer or hybrid-based nanofibrous membranes with stimuli-responsive characteristics further enhances their versatility, enabling them to exhibit broad-spectrum or specific activity against diverse microorganisms. In this review, we elucidate the pivotal advancements achieved in the realm of stimuli-responsive antimicrobial electrospun nanofibers operating by light, temperature, pH, humidity, and electric field, among others. We provide a concise introduction to the strategies employed to design smart electrospun nanofibers with antimicrobial properties. The core section of our review spotlights recent progress in electrospun nanofiber-based systems triggered by single- and multi-stimuli. Within each stimulus category, we explore recent examples of nanofibers based on different polymers and antimicrobial agents. Finally, we delve into the constraints and future directions of stimuli-responsive nanofibrous materials, paving the way for their wider application spectrum and catalyzing progress toward industrial utilization.

Fabrication and characterization of lipopeptide biosurfactant-based electrospun nanofibers for use in tissue engineering

Nanofibers are a class of nanomaterial with specific physicochemical properties and characteristics making them quite sought after and investigated by researchers. Lipopeptide biosurfactant (LPB) formulation properties were previously established in wound healing. LPB were isolated from in vitro culture of Acinetobacter junii B6 and loaded on nanofibers formulation produced by electrospinning method with different ratios of carboxymethylcellulose (CMC), polyvinyl alcohol (PVA), and Poloxamer. Numerous experimental control tests were carried out on formulations, including physicochemical properties which were evaluated by using dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FT-IR), morphology study by scanning electron microscopy (SEM), and thermal stability. The best nanofibers formulation was obtained by the electrospinning method, with a voltage of 19.8 volts, a discharge capacity of 1cm/h, a cylindrical rotating velocity of 100rpm, and a needle interval of 7cm from the cylinder, which continued for 7hours. The formulation contained 2% (w/v) CMC, 10% (w/v) poloxamer, 9% (w/v) PVA, and 5% (w/v) LPB. This formula had desirable physicochemical properties including spreadability, stability, and uniformity with the particle size of about 590nm.

Citric Acid Catalyst-Assisted Bioactive Glass with Hydrogen Peroxide for In Vitro Bioactivity and Biodegradability Using Sol-Gel Method

In this study, carbon-free and completely soluble hydrogen peroxide (H2O2) was utilized in place of conventional surfactants as a pore-forming agent. Citric acid was also used in low concentration for the hydrolysis reaction. A sol-gel method was used to prepare bioactive glass (BG) specimens of H2O2-untreated BG, 1M, 2M, and 3M H2O2-treated BGs. X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), energy-dispersive spectroscopy (EDS), and nitrogen adsorption/desorption isotherm with the Brunauer-Emmett-Teller (BET) method were used for analyzing the samples' phase, surface morphology, chemical composition, constituent composition, pore size, and specific surface area respectively. In vitro bioactivity, as well as biodegradability tests, was performed on samples by immersing them in simulated body fluid (SBF) solution. According to the results, BG particles treated with 2 M H2O2 exhibited higher specific surface area (SSA), which is 189.55 cc/g, and better in vitro bioactivity and biodegradability.

Development, Characterization, and Burn Wound-Healing Potential of Neomycin-Loaded Clay-Reinforced Nanofibers

Background: Skin wounds affect millions of individuals around the world, and their treatment is expensive. Objective: The purpose of this study was to make neomycin-loaded CG/PVA/PAN (NCPP) nanofibers to improve wound healing. Methods: The NCPP nanofibers were characterized by using thermogravimetric analysis (TGA), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy, and X-ray diffraction. Drug solubility, dissolution, swelling ratio, erosion, and antibacterial studies were performed. The in vivo wound healing study of nanofibers was performed in a rabbit model and was supported by % age wound closure and histopathology. Results: The results of SEM showed some sort of agglomeration on the surface of fibers, while TGA showed 10% more stability for drug-loaded nanofibers. The drug permeation study indicated that the formulation with 15% PVA showed a controlled release profile of the drug. The NCPP nanofibers had an appreciable water retention capability. The NCPP nanofibers showed appreciable antibacterial activity against Enterococcus faecalis (Gram-positive bacteria) and Klebsiella pneumonia (Gram-negative bacteria). The wound healing study showed the better healing properties of NCPP nanofibers within 15 days. Conclusion: The findings helped us to conclude that the NCPP nanofibers were successfully fabricated and found to have a promising role in infected wound healing.

Antifouling Zwitterionic Nanofibrous Wound Dressing for Long-Lasting Antibacterial Photodynamic Therapy

Nanofibrous mats as a wound dressing have received great attention in recent year. The development of biocompatible dressings with antibiofouling capability and long-lasting antibacterial properties is important but challenging. Antibacterial photodynamic therapy (aPDT) effectively eliminates pathogens via a photodynamic process that can circumvent the emergence of antibiotic-resistant pathogens. In this study, we integrated the zwitterionic materials (2-methacryloyloxyethyl phosphorylcholine (MPC) moiety) and aPDT photosensitizer, methylene blue (MB), to fabricate a long-lasting antibacterial nanofibrous mat using electrospinning technology. The prepared nanofibers possessed an appropriate water absorption and retention ability, superior cytocompatibility, and antibiofouling ability against both proteins and L929 cell adhesion. MB-loaded nanofibrous mats have exhibited superior aPDT against Gram-positive Staphylococcus aureus compared to Gram-negative Escherichia coli under moderate irradiation (100 W m-2) due to the presence of an extra outer membrane of Gram-negative bacteria serving as a protective barrier. In vitro release study demonstrated that the nanofibrous mat had a long-lasting drug release profile, which can efficiently suppress bacterial growth via aPDT. The antibacterial ability of the MB-loaded nanofibrous mat was commensurate or slightly inferior to antibiotics such as tetracycline and kanamycin, suggesting that it has the potential to be used as an antibiotic alternative. Overall, this zwitterionic nanofibrous mat with long-lasting aPDT function and nonadherent properties has potential as a promising antibacterial wound dressing.

Oxygen releasing patches based on carbohydrate polymer and protein hydrogels for diabetic wound healing: A review

Diabetic wounds are among the major healthcare challenges, consuming billions of dollars of resources and resulting in high numbers of morbidity and mortality every year. Lack of sufficient oxygen supply is one of the most dominant causes of impaired healing in diabetic wounds. Numerous clinical and experimental studies have demonstrated positive outcomes as a result of delivering oxygen at the diabetic wound site, including enhanced angiogenesis, antibacterial and cell proliferation activities. However, prolonged and sustained delivery of oxygen to improve the wound healing process has remained a major challenge due to rapid release of oxygen from oxygen sources and limited penetration of oxygen into deep skin tissues. Hydrogels made from sugar-based polymers such as chitosan and hyaluronic acid, and proteins such as gelatin, collagen and hemoglobin have been widely used to deliver oxygen in a sustained delivery mode. This review presents an overview of the recent advances in oxygen releasing hydrogel based patches as a therapeutic modality to enhance diabetic wound healing. Various types of oxygen releasing wound healing patch have been discussed along with their fabrication method, release profile, cytocompatibility and in vivo results. We also briefly discuss the challenges and prospects related to the application of oxygen releasing biomaterials as wound healing therapeutics.

Creation of Chitosan-Based Nanocapsule-in-Nanofiber Structures for Hydrophobic/Hydrophilic Drug Co-Delivery and Their Dressing Applications in Diabetic Wounds

Nanofiber meshes (NFMs) loaded with therapeutic agents are very often employed to treat hard-to-heal wounds such as diabetic wounds. However, most of the NFMs have limited capability to load multiple or hydrophilicity distinctive-therapeutic agents. The therapy strategy is therefore significantly hampered. To tackle the innate drawback associated with the drug loading versatility, a chitosan-based nanocapsule-in-nanofiber (NC-in-NF) structural NFM system is developed for simultaneous loading of hydrophobic and hydrophilic drugs. Oleic acid-modified chitosan is first converted into NCs by the developed mini-emulsion interfacial cross-linking procedure, followed by loading a hydrophobic anti-inflammatory agent Curcumin (Cur) into the NCs. Sequentially, the Cur-loaded NCs are successfully introduced into reductant-responsive maleoyl functional chitosan/polyvinyl alcohol NFMs containing a hydrophilic antibiotic Tetracycline hydrochloride. Having a co-loading capability for hydrophilicity distinctive agents, biocompatibility, and a controlled release property, the resulting NFMs have demonstrated the efficacy on promoting wound healing either in normal or diabetic rats.

Green Synthesis of Polycyclodextrin/Drug Inclusion Complex Nanofibrous Hydrogels: pH-Dependent Release of Acyclovir

The development of an approach or a material for wound healing treatments has drawn a lot of attention for decades and has been an important portion of the research in the medical industry. Especially, there is growing interest and demand for the generation of wound care products using eco-friendly conditions. Electrospinning is one of these methods that enables the production of nanofibrous materials with attractive properties for wound healing under mild conditions and by using sustainable sources. In this study, starch-derived cyclodextrin (hydroxypropyl-β-cyclodextrin (HPβCD)) was used both for forming an inclusion complex (IC) with acyclovir, a well-known antiviral drug, and for electrospinning of free-standing nanofibers. The nanofibers were produced in an aqueous system, without using a carrier polymer matrix and toxic solvent/chemical. The ultimate HPβCD/acyclovir-IC nanofibers were thermally cross-linked by using citric acid, listed in the generally regarded as safe (GRAS) category by the US Food and Drug Administration (FDA). The cross-linked HPβCD/acyclovir-IC nanofibers displayed stability in aqueous medium. The hydrogel-forming feature of nanofibers was confirmed with their high swelling profile in water in the range of ∼610-810%. Cellulose acetate (CA)/acyclovir nanofibers were also produced as the control sample. Due to inclusion complexation with HPβCD, the solubility of acyclovir was improved, so cross-linked HPβCD/acyclovir-IC nanofibrous hydrogels displayed a better release performance compared to CA/acyclovir nanofibers. Here, a pH-dependent release profile was obtained (pH 5.4 and pH 7.4) besides their attractive swelling features. Therefore, the cross-linked HPβCD/acyclovir-IC nanofibrous hydrogel can be a promising candidate as a wound healing dressing for the administration of antiviral drugs by holding the unique properties of CD and electrospun nanofibers.

Antifungal Activity of Chitosan/Poly(Ethylene Oxide) Blend Electrospun Polymeric Fiber Mat Doped with Metallic Silver Nanoparticles

In this work, the implementation of advanced functional coatings based on the combination of two compatible nanofabrication techniques such as electrospinning and dip-coating technology have been successfully obtained for the design of antifungal surfaces. In a first step, uniform and beadless electrospun nanofibers of both polyethylene oxide (PEO) and polyethylene (PEO)/chitosan (CS) blend samples have been obtained. In a second step, the dip-coating process has been gradually performed in order to ensure an adequate distribution of silver nanoparticles (AgNPs) within the electrospun polymeric matrix (PEO/CS/AgNPs) by using a chemical reduction synthetic process, denoted as in situ synthesis (ISS). Scanning electron microscopy (SEM) has been used to evaluate the surface morphology of the samples, showing an evolution in average fiber diameter from 157 ± 43 nm (PEO), 124 ± 36 nm (PEO/CS) and 330 ± 106 nm (PEO/CS/AgNPs). Atomic force microscopy (AFM) has been used to evaluate the roughness profile of the samples, indicating that the ISS process induced a smooth roughness surface because a change in the average roughness Ra from 84.5 nm (PEO/CS) up to 38.9 nm (PEO/CS/AgNPs) was observed. The presence of AgNPs within the electrospun fiber mat has been corroborated by UV-Vis spectroscopy thanks to their characteristic optical properties (orange film coloration) associated to the Localized Surface Plasmon Resonance (LSPR) phenomenon by showing an intense absorption band in the visible region at 436 nm. Energy dispersive X-ray (EDX) profile also indicates the existence of a peak located at 3 keV associated to silver. In addition, after doping the electrospun nanofibers with AgNPs, an important change in the wettability with an intrinsic hydrophobic behavior was observed by showing an evolution in the water contact angle value from 23.4° ± 1.3 (PEO/CS) up to 97.7° ± 5.3 (PEO/CS/AgNPs). The evaluation of the antifungal activity of the nanofibrous mats against Pleurotus ostreatus clearly indicates that the presence of AgNPs in the outer surface of the nanofibers produced an important enhancement in the inhibition zone during mycelium growth as well as a better antifungal efficacy after a longer exposure time. Finally, these fabricated electrospun nanofibrous membranes can offer a wide range of potential uses in fields as diverse as biomedicine (antimicrobial against human or plant pathogen fungi) or even in the design of innovative packaging materials for food preservation.

Perspectives of nanofibrous wound dressings based on glucans and galactans - A review

Wound healing is a complex and dynamic process that needs an appropriate environment to overcome infection and inflammation to progress well. Wounds lead to morbidity, mortality, and a significant economic burden, often due to the non-availability of suitable treatments. Hence, this field has lured the attention of researchers and pharmaceutical industries for decades. As a result, the global wound care market is expected to be 27.8 billion USD by 2026 from 19.3 billion USD in 2021, at a compound annual growth rate (CAGR) of 7.6 %. Wound dressings have emerged as an effective treatment to maintain moisture, protect from pathogens, and impede wound healing. However, synthetic polymer-based dressings fail to comprehensively address optimal and quick regeneration requirements. Natural polymers like glucan and galactan-based carbohydrate dressings have received much attention due to their inherent biocompatibility, biodegradability, inexpensiveness, and natural abundance. Also, nanofibrous mesh supports better proliferation and migration of fibroblasts because of their large surface area and similarity to the extracellular matrix (ECM). Thus, nanostructured dressings derived from glucans and galactans (i.e., chitosan, agar/agarose, pullulan, curdlan, carrageenan, etc.) can overcome the limitations associated with traditional wound dressings. However, they require further development pertaining to the wireless determination of wound bed status and its clinical assessment. The present review intends to provide insight into such carbohydrate-based nanofibrous dressings and their prospects, along with some clinical case studies.

Engineering of clarithromycin loaded stimulus responsive dissolving microneedle patches for the treatment of biofilms

This study aimed to fabricate clarithromycin laden Eudragit S-100-based microfibers (MF), microfibers coated film (MB), clarithromycin loaded polyvinyl pyrollidone, hyaluronic acid and sorbitol-based dissolving microneedle patches (CP) and microfibers coated microneedle patches (MP). Morphological and phase analysis of formulations were carried out by scanning electron microscopy and differential scanning calorimetry, X-ray diffraction, respectively. Substrate liquefaction test, in vitro drug release, antimicrobial assay and in vivo antibiofilm studies were performed. MF exhibited a uniform surface and interconnected network. Morphological analysis of CP revealed sharp-tipped and uniform-surfaced microstructures. Clarithromycin was incorporated within MF and CP as amorphous solid. Liquefaction test indicated hyaluronate lyase enzyme responsiveness of hyaluronic acid. Fibers-based formulations (MF, MB and MP) provided an alkaline pH (7.4) responsive drug release; ∼79 %, ∼78 % and ∼81 %, respectively within 2 hours. CP showed a drug release of ∼82 % within 2 hours. MP showed ∼13 % larger inhibitory zone against Staphylococcus aureus (S. aureus) as compared to MB and CP. A relatively rapid eradication of S. aureus in infected wounds and subsequent skin regeneration was observed following MP application as compared to MB and CP indicating its usefulness for the management of microbial biofilms.

Fabrication, Microstructures and Sensor Applications of Highly Ordered Electrospun Nanofibers: A Review

The review summarizes the fabrication, microstructures, and sensor applications of highly ordered electrospun nanofibers. In the traditional electrospinning process, electrospun nanofibers usually have disordered or random microstructures due to the chaotic oscillation of the electrospinning jet. Different electrospinning methods can be formed by introducing external forces, such as magnetic, electric, or mechanical forces, and ordered nanofibers can be collected. The microstructures of highly ordered nanofibers can be divided into three categories: uniaxially ordered nanofibers, biaxially ordered nanofibers and ordered scaffolds. The three microstructures are each characterized by being ordered in different dimensions. The regulation and control of the ordered microstructures can promote electrospun nanofibers' mechanical and dielectric strength, surface area and chemical properties. Highly ordered electrospun nanofibers have more comprehensive applications than disordered nanofibers do in effect transistors, gas sensors, reinforced composite materials and tissue engineering. This review also intensively summarizes the applications of highly ordered nanofibers in the sensor field, such as pressure sensors, humidity sensors, strain sensors, gas sensors, and biosensors.

Nanofibers in Ocular Drug Targeting and Tissue Engineering: Their Importance, Advantages, Advances, and Future Perspectives

Nanofibers are frequently encountered in daily life as a modern material with a wide range of applications. The important advantages of production techniques, such as being easy, cost effective, and industrially applicable are important factors in the preference for nanofibers. Nanofibers, which have a broad scope of use in the field of health, are preferred both in drug delivery systems and tissue engineering. Due to the biocompatible materials used in their construction, they are also frequently preferred in ocular applications. The fact that they have a long drug release time as a drug delivery system and have been used in corneal tissue studies, which have been successfully developed in tissue engineering, stand out as important advantages of nanofibers. This review examines nanofibers, their production techniques and general information, nanofiber-based ocular drug delivery systems, and tissue engineering concepts in detail.

Recent Development of Polyhydroxyalkanoates (PHA)-Based Materials for Antibacterial Applications: A Review

The diseases caused by microorganisms are innumerable existing on this planet. Nevertheless, increasing antimicrobial resistance has become an urgent global challenge. Thus, in recent decades, bactericidal materials have been considered promising candidates to combat bacterial pathogens. Recently, polyhydroxyalkanoates (PHAs) have been used as green and biodegradable materials in various promising alternative applications, especially in healthcare for antiviral or antiviral purposes. However, it lacks a systematic review of the recent application of this emerging material for antibacterial applications. Therefore, the ultimate goal of this review is to provide a critical review of the state of the art recent development of PHA biopolymers in terms of cutting-edge production technologies as well as promising application fields. In addition, special attention was given to collecting scientific information on antibacterial agents that can potentially be incorporated into PHA materials for biological and durable antimicrobial protection. Furthermore, the current research gaps are declared, and future research perspectives are proposed to better understand the properties of these biopolymers as well as their possible applications.

Physical Chemistry Study of Collagen-Based Multilayer Films

The surface properties of a biomaterial play an important role in cell behavior, e.g., recolonization, proliferation, and migration. Collagen is known to favor wound healing. In this study, collagen (COL)-based layer-by-layer (LbL) films were built using different macromolecules as a partner, i.e., tannic acid (TA), a natural polyphenol known to establish hydrogen bonds with protein, heparin (HEP), an anionic polysaccharide, and poly(sodium 4-styrene sulfonate) (PSS), an anionic synthetic polyelectrolyte. To cover the whole surface of the substrate with a minimal number of deposition steps, several parameters of the film buildup were optimized, such as the pH value of the solutions, the dipping time, and the salt (sodium chloride) concentration. The morphology of the films was characterized by atomic force microscopy. Built at an acidic pH, the stability of COL-based LbL films was studied when in contact with a physiological medium as well as the TA release from COL/TA films. In contrast to COL/PSS and COL/HEP LbL films, COL/TA films showed a good proliferation of human fibroblasts. These results validate the choice of TA and COL as components of LbL films for biomedical coatings.

Therapeutic Efficacy of Polymeric Biomaterials in Treating Diabetic Wounds-An Upcoming Wound Healing Technology

Diabetic wounds are one of the serious, non-healing, chronic health issues faced by individuals suffering from diabetic mellitus. The distinct phases of wound healing are either prolonged or obstructed, resulting in the improper healing of diabetic wounds. These injuries require persistent wound care and appropriate treatment to prevent deleterious effects such as lower limb amputation. Although there are several treatment strategies, diabetic wounds continue to be a major threat for healthcare professionals and patients. The different types of diabetic wound dressings that are currently used differ in their properties of absorbing wound exudates and may also cause maceration to surrounding tissues. Current research is focused on developing novel wound dressings incorporated with biological agents that aid in a faster rate of wound closure. An ideal wound dressing material must absorb wound exudates, aid in the appropriate exchange of gas, and protect from microbial infections. It must support the synthesis of biochemical mediators such as cytokines, and growth factors that are crucial for faster healing of wounds. This review highlights the recent advances in polymeric biomaterial-based wound dressings, novel therapeutic regimes, and their efficacy in treating diabetic wounds. The role of polymeric wound dressings loaded with bioactive compounds, and their in vitro and in vivo performance in diabetic wound treatment are also reviewed.

Release Profiles of Carvacrol or Chlorhexidine of PLA/Graphene Nanoplatelets Membranes Prepared Using Electrospinning and Solution Blow Spinning: A Comparative Study

Nanofibrous membranes are often the core components used to produce devices for a controlled release and are frequently prepared by electrospinning (ES). However, ES requires high production times and costs and is not easy to scale. Recently, solution blow spinning (SBS) has been proposed as an alternative technique for the production of nanofibrous membranes. In this study, a comparison between these two techniques is proposed. Poly (lactic acid)-based nanofibrous membranes were produced by electrospinning (ES) and solution blow spinning (SBS) in order to evaluate the different effect of liquid (carvacrol, CRV) or solid (chlorhexidine, CHX) molecules addition on the morphology, structural properties, and release behavior. The outcomes revealed that both ES and SBS nanofibrous mat allowed for obtaining a controlled release up to 500 h. In detail, the lower wettability of the SBS system allowed for slowing down the CRV release kinetics, compared to the one obtained for ES membranes. On the contrary, with SBS, a faster CHX release can be obtained due to its more hydrophilic behavior. Further, the addition of graphene nanoplatelets (GNP) led to a decrease in wettability and allowed for a slowing down of the release kinetics in the whole of the systems.

Biomaterials Based on Organic Polymers and Layered Double Hydroxides Nanocomposites: Drug Delivery and Tissue Engineering

The development of biomaterials has a substantial role in pharmaceutical and medical strategies for the enhancement of life quality. This review work focused on versatile biomaterials based on nanocomposites comprising organic polymers and a class of layered inorganic nanoparticles, aiming for drug delivery (oral, transdermal, and ocular delivery) and tissue engineering (skin and bone therapies). Layered double hydroxides (LDHs) are 2D nanomaterials that can intercalate anionic bioactive species between the layers. The layers can hold metal cations that confer intrinsic biological activity to LDHs as well as biocompatibility. The intercalation of bioactive species between the layers allows the formation of drug delivery systems with elevated loading capacity and modified release profiles promoted by ion exchange and/or solubilization. The capacity of tissue integration, antigenicity, and stimulation of collagen formation, among other beneficial characteristics of LDH, have been observed by in vivo assays. The association between the properties of biocompatible polymers and LDH-drug nanohybrids produces multifunctional nanocomposites compatible with living matter. Such nanocomposites are stimuli-responsive, show appropriate mechanical properties, and can be prepared by creative methods that allow a fine-tuning of drug release. They are processed in the end form of films, beads, gels, monoliths etc., to reach orientated therapeutic applications. Several studies attest to the higher performance of polymer/LDH-drug nanocomposite compared to the LDH-drug hybrid or the free drug.

Herbal Products and Their Active Constituents for Diabetic Wound Healing-Preclinical and Clinical Studies: A Systematic Review

The purpose of this review is to provide verified data on the current knowledge acquired in preclinical and clinical studies regarding topically used herbal products and their active constituents (formulations and dressings) with diabetic wound healing activity. Moreover, herbal products and their active constituents used for diabetic wound infections, and various cellular and molecular mechanisms of their actions will also be described. The electronic databases were searched for articles published from 2012 to 2022. Publications with oral or systemic administration of herbal products in diabetic wound healing, published before 2012, available only as an abstract, or in languages other than English were excluded from the study. The 59 articles comparing topically used herbal products in diabetic wound healing treatment versus control treatments (placebo or active therapy) were selected. Herbal products through different mechanisms of action, including antimicrobial, anti-inflammatory, antioxidant activity, stimulation of angiogenesis, production of cytokines and growth factors, keratinocytes, and fibroblast migration and proliferation may be considered as an important support during conventional therapy or even as a substitute for synthetic drugs used for diabetic wound treatment.

Icy core-shell composite nanofibers with cooling, antibacterial and healing properties for outdoor burns

Burns are usually difficult to treat because their susceptibe to bacterial infections. When burns is accompanied by hyperthermia, the heat accumulated on the skin will causes extensive tissue damage. Most dressings focus on the treatment process, while ignoring the first-aid treatment to remove hyperthermia. To make matters worse, when outdoors, it is hard to find clean water to wash and cool the burned area. A dressing which can simultaneously realize first-time cooling and repairing treatment of the burned area can shorten treatment time, and is especially beneficial for outdoor use. In this study, a handheld coaxial electrospinning device is developed for preparing platelet-rich plasma @Polycaprolactone-epsilon polylysine (PRP@PCL/ε-PL) core-shell nanofibers. The nanofibers can be synchronously transformed into ice fibers during the spinning process, and directly deposited on the skin. The whole process is convenient to use outdoor. Via dual cooling mechanisms, first aid can take away the excessive heat in the burn area by nanofibers. These core-shell nanofibers also show its excellent antimicrobial and tissue regeneration-promoting properties. Therefore, it achieves first-time cooling and repair treatment of the burned area at the same time. Moreover, due to direct in-situ deposition of this handheld coaxial electrospinning, better antimicrobial properties, and faster healing performance are achieved. By using this integrated strategy that combines cooling, antibacterial and healing promotion, the burn recovery time is shortened from 21 days to 14 days.

Tailoring micro/nano-fibers for biomedical applications

Nano/micro fibers have evoked much attention of scientists and have been researched as cutting edge and hotspot in the area of fiber science in recent years due to the rapid development of various advanced manufacturing technologies, and the appearance of fascinating and special functions and properties, such as the enhanced mechanical strength, high surface area to volume ratio and special functionalities shown in the surface, triggered by the nano or micro-scale dimensions. In addition, these outstanding and special characteristics of the nano/micro fibers impart fiber-based materials with wide applications, such as environmental engineering, electronic and biomedical fields. This review mainly focuses on the recent development in the various nano/micro fibers fabrication strategies and corresponding applications in the biomedical fields, including tissue engineering scaffolds, drug delivery, wound healing, and biosensors. Moreover, the challenges for the fabrications and applications and future perspectives are presented.

A Straightforward Approach towards Antibacterial and Anti-Inflammatory Multifunctional Nanofiber Membranes with Sustained Drug Release Profiles

Preventing bacterial infection and controlling the inflammatory response occupy important positions in wound treatment. Although loading wound dressings with antibacterial or anti-inflammatory drugs/molecules is an effective approach to address these issues, simultaneous sustained release of these drugs remains challenging. Herein, hydrophilic polyhexamethylene guanidine hydrochloride (PHGC) and hydrophobic indomethacin (Indo) are loaded in hydrophilic polyvinyl alcohol (PVA) and hydrophobic polycaprolactone (PCL) nanofibers respectively by bidirectional electrospinning to form an antibacterial and anti-inflammatory PCL-Indo/PVA-PHGC wound dressing. The fabricated nanofiber membrane exhibits 100% disinfection activity to both Gram-negative (E. coli) and Gram-positive (S. aureus) bacteria because of the release of the broad-spectrum antibacterial molecule PHGC. Additionally, the loading of Indo in the nanofiber membrane enhances the expression level of IL-10, while inhibiting those of IL-6 and TNF-α in the RAW264.7 mouse cells. In the interwoven membrane of PCL and PVA fibers, the release of hydrophobic Indo is hindered by hydrophilic PHGC and PVA fibers, and similarly, the release of hydrophilic PHGC is hindered by hydrophobic Indo and PCL fibers. In conclusion, the PCL-Indo/PVA-PHGC nanofiber membrane has excellent antibacterial, anti-inflammatory, and sustained-release effects, and thus regulates the immune microenvironment of the cells to potentially promote wound healing.

Thermally Treated Berberine-Loaded SA/PVA/PEO Electrospun Microfiber Membranes for Antibacterial Wound Dressings

This study aimed to develop a safe and advanced antibacterial material of electrospun microfiber membranes (MFMs) for wound dressings. Combinations of several materials were investigated; thermal treatment and electrospinning techniques were used to form the best quality of MFMs to suit its end applications. By comparing the fiber morphology, diameter changes, and fracture strength, the suitable ratio of raw materials and thermal treatment were obtained before and after adding Trition X-100 as a surfactant for MFMs of sodium alginate/polyvinyl alcohol/polyethylene oxide (SA/PVA/PEO). The electrospinning solution was mixed with berberine as an antibacterial substance; meanwhile, calcium chloride (CaCl₂) was used as the crosslinking agent. The antibacterial properties, water dissolution resistance, water content, and fracture strength were thoroughly investigated. The results showed that the antibacterial rates of MFMs with different mass fractions of berberine (0, 3, and 5 wt.%) to Escherichia coli (E. coli) were 14.7, 92.9, and 97.2%, respectively. The moisture content and fracture strength of MFMs containing 5 wt.% berberine were 72.0% and 7.8 MPa, respectively. In addition, the produced MFMs embodied great water dissolution resistance. Berberine-loaded SA/PVA/PEO MFMs could potentially serve as an antibacterial wound dressing substrate with low cost and small side effects.

Co-electrospun poly(vinyl alcohol)/poly(ɛ-caprolactone) nanofiber scaffolds containing coffee and Calendula officinalis extracts for wound healing applications

Fabrication of a biocompatible nanofibrous dressing with the advantage of the inclusion of bioactive herbal extracts is a promising approach in skin tissue engineering and wound healing applications. Herbal extracts possess many properties to promote the wound healing process, such as antioxidant properties, anti-inflammation activities as well as enhancing fibroblasts proliferation and migration.

In this study, Calendula officinalis ( C. officinalis) and coffee extracts were loaded into poly(vinyl alcohol)/poly(ɛ-caprolactone) (PVA/PCL) nanofibrous mats. The obtained scaffolds were then characterized using scanning electron microscopy (SEM), attenuated total reflection Fourier transform infrared (ATR-FTIR), contact angle, and mechanical measurements. Also, the antioxidant activity, scratch assay, and cell viability of fibroblast cells were also evaluated. The results showed PVA/PCL scaffold loaded with 10 wt% C. officinalis and coffee extracts displayed smooth homogenous morphology with 317 ± 106 nm average diameter. Moreover, the relevant analyses confirmed that the extracts were incorporated into the nanofibers with suitable hydrophilicity and higher mechanical strength (4 ± 0.4 MPa). The antioxidant assay showed that IC50 values of coffee and C. officinalis extracts were 46 ± 1 ppm and 101 ± 4 ppm, successively, which presented a high antioxidant activity. The combination of both extracts showed a higher rate of migration than individual extracts with not detected cytotoxic effects on the human dermal fibroblast cells. In conclusion, our results confirmed that the coffee and C. officinalis extracts loaded PVA/PCL nanofibrous scaffolds could provide an appropriate construct for wound healing applications.

Erythromycin Formulations—A Journey to Advanced Drug Delivery

Erythromycin (ERY) is a macrolide compound with a broad antimicrobial spectrum which is currently being used to treat a large number of bacterial infections affecting the skin, respiratory tract, intestines, bones and other systems, proving great value from a clinical point of view. It became popular immediately after its discovery in 1952, due to its therapeutic effect against pathogens resistant to other drugs. Despite this major advantage, ERY exhibits several drawbacks, raising serious clinical challenges. Among them, the very low solubility in water and instability under acidic conditions cause a limited efficacy and bioavailability. Apart from this, higher doses promote drug resistance and undesirable effects. In order to overcome these disadvantages, during the past decades, a large variety of ERY formulations, including nanoparticles, have emerged. Despite the interest in ERY-(nano)formulations, a review on them is lacking. Therefore, this work was aimed at reviewing all efforts made to encapsulate ERY in formulations of various chemical compositions, sizes and morphologies. In addition, their preparation/synthesis, physico-chemical properties and performances were carefully analysed. Limitations of these studies, particularly the quantification of ERY, are discussed as well.

Generation of cost-effective MXene@polydopamine-decorated chitosan nanofibrous wound dressing for promoting wound healing

Herein, we designed and fabricated a MXene@polydopamine (MXene@PDA)-decorated chitosan non-woven fabric (M-CNF) hemostatic dressing with super hydrophilic properties for wound repair and regeneration. The M-CNF exhibit excellently wettability characteristics which can rapidly absorb water from blood. Moreover, M-CNF with 15 mg/mL MXene@PDA (M-CNF-15) show better antibacterial performance, excellent blood-clotting performance, better blood cell and platelet adhesion ability than CNF, displaying both active and passive hemostatic mechanisms to accelerate blood clotting in mouse-liver injury model. In addition, the M-CNF-15 also shows better wound healed performance than Tegaderm™ film in a full-thickness skin defect model, and further demonstrating that the MXene@PDA can promote fibrinogen reformation the at the initial phases of the wound healing process. Therefore, this strategy for designing and manufacturing of multi-functional M-CNF wound dressing will have great potential for active local hemostasis and wound repair and regeneration.