Preparation, Characterization, and Release of Amoxicillin from Electrospun Fibrous Wound Dressing Patches

Multilayer PVA/gelatin nanofibrous scaffolds incorporated with Tanacetum polycephalum essential oil and amoxicillin for skin tissue engineering application

Wound infection is still an important challenge in healing of different types of skin injuries. This highlights the need for new and improved antibacterial agents with novel and different mechanisms of action. In this study, by electrospinning process Tanacetum polycephalum essential oil (EO), as a natural antibacterial and anti-inflammatory agent, along with Amoxicillin (AMX) as an antibiotic are incorporated into PVA/gelatin-based nanofiber mats individually and in combination to fabricate a novel wound dressing. Briefly, we fabricated PVA/gelatin loaded by Amoxicillin as first layer for direct contact with wound surface to protects the wound from exogenous bacteria, and then built a PVA/gelatin/Tanacetum polycephalum essential oil layer on the first layer to help cleanses the wound from infection and accelerates wound closure. Finally, PVA/gelatin layer as third layer fabricated on middle layer to guarantee desirable mechanical properties. For each layer, the electrospinning parameters were adjusted to form bead-free fibers. The morphology of fabricated nanofiber scaffolds was characterized by Fourier-transform infrared (FTIR) and scanning electron microscopy (SEM). Microscopic images demonstrated the smooth bead-free microstructures fabrication of every layer of nanofiber with a uniform fiber size of 126.888 to 136.833 nm. While, EO and AMX increased the diameter of nanofibers but there was no change in physical structure of nanofiber. The water contact angle test demonstrated hydrophilicity of nanofibers with 47.35°. Although EO and AMX had little effect on reducing hydrophilicity but nanofibers with contact angle between 51.4° until 65.4° are still hydrophilic. Multilayer nanofibers loaded by EO and AMX killed 99.99 % of both gram-negative and gram-positive bacteria in comparison with control and PVA/gelatin nanofiber. Also, in addition to confirming the non-toxicity of nanofibers, MTT results also showed the acceleration of cell proliferation. In vivo wound evaluation in mouse models showed that designed nanofibrous scaffolds could be an appropriate option for wound treatment due to their positive effect on angiogenesis, collagen deposition, granulation tissue formation, epithelialization, and wound closure.

Recent Advances in Electrospun Nanofiber-Based Strategies for Diabetic Wound Healing Application

Diabetic ulcers are the second largest complication caused by diabetes mellitus. A great number of factors, including hyperchromic inflammation, susceptible microbial infection, inferior vascularization, the large accumulation of free radicals, and other poor healing-promoting microenvironments hold back the healing process of chronic diabetic ulcer in clinics. With the increasing clinical cases of diabetic ulcers worldwide, the design and development of advanced wound dressings are urgently required to accelerate the treatment of skin wounds caused by diabetic complications. Electrospinning technology has been recognized as a simple, versatile, and cost-reasonable strategy to fabricate dressing materials composed of nanofibers, which possess excellent extracellular matrix (ECM)-mimicking morphology, structure, and biological functions. The electrospinning-based nanofibrous dressings have been widely demonstrated to promote the adhesion, migration, and proliferation of dermal fibroblasts, and further accelerate the wound healing process compared with some other dressing types like traditional cotton gauze and medical sponges, etc. Moreover, the electrospun nanofibers are commonly harvested in the structure of nonwoven-like mats, which possess small pore sizes but high porosity, resulting in great microbial barrier performance as well as excellent moisture and air permeable properties. They also serve as good carriers to load various bioactive agents and/or even living cells, which further impart the electrospinning-based dressings with predetermined biological functions and even multiple functions to significantly improve the healing outcomes of different chronic skin wounds while dramatically shortening the treatment procedure. All these outstanding characteristics have made electrospun nanofibrous dressings one of the most promising dressing candidates for the treatment of chronic diabetic ulcers. This review starts with a brief introduction to diabetic ulcer and the electrospinning process, and then provides a detailed introduction to recent advances in electrospinning-based strategies for the treatment of diabetic wounds. Importantly, the synergetic application of combining electrospinning with bioactive ingredients and/or cell therapy was highlighted. The review also discussed the advantages of hydrogel dressings by using electrospun nanofibers. At the end of the review, the challenge and prospects of electrospinning-based strategies for the treatment of diabetic wounds are discussed in depth.

Biocompatible polyvinyl alcohol nanofibers loaded with amoxicillin and salicylic acid to prevent wound infections

Diabetic wounds are one of the most challenging clinical conditions in diabetes, necessitating the development of new treatments to foster healing and prevent microbial contamination. In this study, polyvinyl alcohol was used as a matrix polymer, and amoxicillin (AMX) and salicylic acid (SA) were selected as bioactive compounds with antimicrobial (with AMX) and anti-inflammatory action (with SA) to obtain innovative drug-loaded electrospun nanofiber patches for the management of diabetic wounds. Scanning electron microscope images revealed the uniform and beadless structure of the nanofiber patches. Mechanical tests indicated that AMX minimally increased the tensile strength, while SA significantly reduced it. The patches demonstrated effective antibacterial activity against both gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) strains. The potential of these patches in the development of novel wound dressings is highlighted by the excellent biocompatibility with fibroblast cells maintained for up to 7 d.

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.

Topically Applied Biopolymer-Based Tri-Layered Hierarchically Structured Nanofibrous Scaffold with a Self-Pumping Effect for Accelerated Full-Thickness Wound Healing in a Rat Model

Wound healing has grown to be a significant problem at a global scale. The lack of multifunctionality in most wound dressing-based biopolymers prevents them from meeting all clinical requirements. Therefore, a multifunctional biopolymer-based tri-layered hierarchically nanofibrous scaffold in wound dressing can contribute to skin regeneration. In this study, a multifunctional antibacterial biopolymer-based tri-layered hierarchically nanofibrous scaffold comprising three layers was constructed. The bottom and the top layers contain hydrophilic silk fibroin (SF) and fish skin collagen (COL), respectively, for accelerated healing, interspersed with a middle layer of hydrophobic poly-3-hydroxybutyrate (PHB) containing amoxicillin (AMX) as an antibacterial drug. The advantageous physicochemical properties of the nanofibrous scaffold were estimated by SEM, FTIR, fluid uptake, contact angle, porosity, and mechanical properties. Moreover, the in vitro cytotoxicity and cell healing were assessed by MTT assay and the cell scratching method, respectively, and revealed excellent biocompatibility. The nanofibrous scaffold exhibited significant antimicrobial activity against multiple pathogenic bacteria. Furthermore, the in vivo wound healing and histological studies demonstrated complete wound healing in wounded rats on day 14, along with an increase in the expression level of the transforming growth factor-β1 (TGF-β1) and a decrease in the expression level of interleukin-6 (IL-6). The results revealed that the fabricated nanofibrous scaffold is a potent wound dressing scaffold, and significantly accelerates full-thickness wound healing in a rat model.

In Vitro and In Vivo Characterization Methods for Evaluation of Modern Wound Dressings

Chronic wound management represents a major challenge in the healthcare sector owing to its delayed wound-healing process progression and huge financial burden. In this regard, wound dressings provide an appropriate platform for facilitating wound healing for several decades. However, adherent traditional wound dressings do not provide effective wound healing for highly exudating chronic wounds and need the development of newer and innovative wound dressings to facilitate accelerated wound healing. In addition, these dressings need frequent changing, resulting in more pain and discomfort. In order to overcome these issues, a wide range of affordable and innovative modern wound dressings have been developed and explored recently to accelerate and improve the wound healing process. However, a comprehensive understanding of various in vitro and in vivo characterization methods being utilized for the evaluation of different modern wound dressings is lacking. In this context, an overview of modern dressings and their complete in vitro and in vivo characterization methods for wound healing assessment is provided in this review. Herein, various emerging modern wound dressings with advantages and challenges have also been reviewed. Furthermore, different in vitro wound healing assays and in vivo wound models being utilized for the evaluation of wound healing progression and wound healing rate using wound dressings are discussed in detail. Finally, a summary of modern wound dressings with challenges and the future outlook is highlighted.

Strategically designed SPEEK nanofibrous scaffold with tailored delivery ofresveratrolfor skin wound regeneration

Electro-spinnable polymeric materials can easily form two-dimensional (2D) nanofibrous scaffolds improving biochemical functionalities specially in the area of skin wound healing and nanomedicine, but it has been hard to achieve this on a highly mechanically stable biopolymer, Poly ether ether ketone (PEEK), due to its intrinsic hydrophobicity and chemical inertness. Herein, we demonstrated a novel nanomedicine healing system consisting of sulphonated poly ether ether ketone combined withresveratrol(SPEEK+RSV), which could act as an effective 2D nano bio-materialin vitroandin vivo, without observable cytotoxicity. The fabricated nanocomposites exhibited enriched skin cell proliferation and adhesion as confirmed from the results of MTT, cell adhesion and live-dead assay. Results of SEM analysis showed a uniform nano-sized distribution with adequate pore size and porosity % facilitating a desired breathable environment at the wound site. The results of FT-IR, tensile studies and TGA analyses confirmed the presence of appropriate bonds and improved mechanical stability of theRSVincorporated nanofibrous scaffold. Results of anti-microbial analysis portrayed good potentiality of the fabricated nanofibers in treating wounds colonized with bacterial infections. Controlled drug release of resveratrol established the bio-compatibility of the nanofibers in skin wound regeneration.In vivoanalysis assessed in female Wistar rats enabled complete wound closure with 100 % wound contraction within 16 days. Results of histopathology analysis through H-E and MT staining presented the re-surfing of the wound environment with regeneration of epithelium, granulation tissue and collagen. Thus, the fabricated 2D nanofibrous scaffold incorporated with pharmaceutical RSV bio-medicine perceptively mimicked skin ECM convincingly aiding the progression of skin wound regeneration mechanism.

Physical-Chemical Aspects of the Preparation and Drug Release of Electrospun Scaffolds

Fibers were spun from a mixture of dichloromethane (DCM) and dimethyl sulfoxide (DMSO) solution of poly(lactic acid)(PLA) containing various amounts of amoxicillin (Amox) as the active component. Composition changes during spinning, structure, solubility, and the location of the drug were considered during the evaluation of drug release and microbial activity. The results showed that the composition of the material changes during the preparation procedure. The solubility of the drug in the components and that of the components in each other is limited, which results in the formation of several phases and the precipitation of the drug. The technology used results in the partitioning of the drug; some is located inside, while the rest is among the fibers. The wetting of the fibers or disks by the water-based dissolution media is poor, the penetration of the liquid into and the diffusion of the active component out of the device takes considerable time. Drug release takes place in one, burst-like step, only Amox located among the fibers dissolve and diffuse into the surrounding medium. The slow second stage of release claimed in the literature is less probable because the size of the Amox molecule is considerably larger than the holes creating the free volume of the polymer. The prepared device has antimicrobial activity, inhibits the growth of the two bacterial strains studied. The time scale of activity is short and corresponds to that of the release experiments and the burst-like behavior of the device. The results clearly prove that physical–chemical factors play a determining role in the effect and efficiency of medical devices prepared from electrospun fibers containing an active component.

Chelidoniummajus L. Incorporated Emulsion Electrospun PCL/PVA_PEC Nanofibrous Meshes for Antibacterial Wound Dressing Applications

Presently, there are many different types of wound dressings available on the market. Nonetheless, there is still a great interest to improve the performance and efficiency of these materials. Concerning that, new dressing materials containing natural products, such as medicinal plants that protect the wound from infections but also enhance skin regeneration have been or are being developed. Herein, we used for the first time a needleless emulsion electrospinning technique for incorporating Chelidoniummajus L. (C. majus), a medicinal plant widely known for its traditional therapeutic properties, in Polycaprolactone (PCL)/Polyvinyl Alcohol (PVA)_Pectin (PEC) nanofibrous meshes. Moreover, the potential use of these electrospun nanofibers as a carrier for C. majus was also explored. The results obtained revealed that the produced PCL/PVA_PEC nanofibrous meshes containing C. majus extract displayed morphological characteristics similar to the natural extracellular matrix of the skin (ECM). Furthermore, the produced meshes showed beneficial properties to support the healing process. Additionally, the C. majus-loaded PCL/PVA_PEC nanofibrous meshes inhibited Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa) growth, reaching a 3.82 Log reduction, and showed to be useful for controlled release, without causing any cytotoxic effect on the normal human dermal fibroblasts (NHDF) cells. Hence, these findings suggest the promising suitability of this novel wound dressing material for prevention and treatment of bacterial wound infections.

A nano approach towards the creation of a biointerface as stimulator of osteogenic differentiation

There is a great need for tissue engineering constructs with the ability to modulate stem cell behavior. The initial adhesion, growth and differentiation of stem cell are a key strategy in bone tissue engineering and it can be controlled through biomaterial-cell interface. Here we engineered a polycaprolactone/gelatin/bioactive glass (PCL/GT/BG) nanocomposite scaffold coated with Fibronectin (FN) as a potential candidate to aid the bone regeneration process by giving cells a temporary template to grow into. For this purpose, initially BG nanoparticles (nBG) of 70 ± 15 nm were synthesized, characterized and then impregnated into PCL/GT matrix to create a nanocomposite fibrous mesh. An optimized structure was selected based on fiber uniformity, diameter, and the mechanical properties. Cell adhesion, growth, and the expression of osteogenic-related genes as a result of FN tethering, through specific surface interactions, was evaluated. Furthermore, the potential of optimized nanofiberous structure as a drug delivery vehicle for the local release of therapeutic agents was studied by using amoxicillin as a model drug. The release profile revealed that around 70% of drug was released in an hour for non-crosslinked fibers (burst release) followed by a gradual release up to 72 h. The release profile was steadier for crosslinked fibers. The scaffold also showed an antibacterial effect against ubiquitous gram-positive Staphylococcus aureus. The current study provides an insight for future researchers who aim to create nanocomposite materials as multifunctional scaffolds for bone tissue engineering applications.

Development of Biodegradable Cosmetic Patch Using a Polylactic Acid/Phycocyanin-Alginate Composite

The usage of non-degradable polymer as the main matrix for a cosmetic patch raises concern, as it can cause environmental pollution when discarded in landfill. Thus, biodegradable polylactic acid (PLA) was chosen in this study, as PLA has non-toxic properties and similar mechanical properties to conventional plastic materials. An active ingredient in a cosmetic patch serves the purpose of providing beneficial ingredients to the skin; therefore, phycocyanin, an extract from spirulina, was chosen, as it possesses antioxidant and anti-inflammatory properties. Alginate was also incorporated with the phycocyanin for fabrication onto the PLA matrix. A preliminary study was first carried out to identify the antioxidant properties and cytotoxic effect of the phycocyanin on skin cells. It was observed that phycocyanin had no cytotoxic effect on the skin and showed good antioxidant activity. PLA/phycocyanin-alginate composite was fabricated using a solvent casting method, and optimization of preparation conditions (phycocyanin/alginate ratio, stirring time, and temperature) were carried out using the one-factor-at-a-time (OFAT) method with responses of elongation at break and releasing properties. Attenuated total reflectance (ATR)-FTIR analysis was also conducted to further analyze the functional group of the composites. Surface morphologies were observed for samples before and after the releasing test. From the analyses conducted, PLA/phycocyanin-alginate composite prepared at a phycocyanin/alginate ratio of 40/60 for 20 h at 20 °C gave the best properties in terms of flexibility of film and releasing properties of phycocyanin.

Fabrication and evaluation of electrospun biomimetic sulphonated PEEK nanofibrous scaffold for human skin cell proliferation and wound regeneration potential

Regeneration of skin wound is a challenging process since functional and architectural restoration of the damaged skin tissue is an arduous task. The use of springing up biomaterials with nano-topographic and bio-mimicking characteristics resembling natural skin's extra cellular matrix (ECM) would be a favorable approach to regenerate such an injured skin tissue. In this study an attempt has been carried out to design and develop sulphonated polyether ether ketone (SPEEK) nanofibrous scaffold to explore its role on skin cell proliferation potential. 2 h-SPEEK portrayed the highest proliferative potential for HaCaT keratinocytes and fibroblasts. It was aimed for the tailored release of bio-actives from the spatiotemporally designed Aloe vera incorporated 2 h-SPEEK nanoscaffold to accelerate the skin wound regeneration. FTIR, EDX and XRD analyses revealed the effective incorporation of Aloe vera in the electrospun nanofibers. SEM analysis revealed the nano-topographical morphology with highly porous, dense and interconnected fibrous structures mimicking the skin ECM. The regulated delivery of Aloe vera demonstrated the biocompatibility of the nanofibrous scaffold in skin keratinocytes (HaCaT) and fibroblasts (3T3) cells through in vitro analysis proving its non-toxic properties. Further, the fabricated nanoscaffolds exhibited excellent anti-microbial efficacy towards the tested human skin pathogenic microbes. The results of in vivo studies in Wistar rat model exhibited scar-less wound healing with complete wound closure. Thus, this nanofiber based drug delivery system implicitly acts as a skin like ECM, bio-mimicking the topographical and chemical cues of the natural skin tissues paving way for a complete regeneration and integration of the injured area strengthening the functional restoration of insulted cells around the wound area.

Improvement in mechanical properties and biodegradability of PLA using poly(ethylene glycol) and triacetin for antibacterial wound dressing applications

Wound is among the most common injuries. A suitable wound dressing has a significant effect on the healing process. In this study, a porous wound dressing was prepared using poly (lactic acid) (PLA) and two plasticizers, polyethylene glycol (PEG) and triacetin (TA), through solvent casting method. For antibacterial activities, metronidazole was incorporated in the structure. The morphology was investigated by scanning electron microscopy (SEM). In addition, the effect of plasticizers ratio on porosity growth was evaluated. It was also observed that each had a unique effect on the structure's porosity. The mechanical properties confirmed the effect of both plasticizers on increasing polymer softness and flexibility, and the most similar formulations to human skin in terms of mechanical properties were introduced. According to the results, TA had stronger effect on mechanical properties. The differential scanning calorimetry (DSC) showed the effect of increasing plasticizer concentration on crystalline structure and Tm reduction of PLA. The water contact angle measurement showed that both plasticizers enhanced hydrophilic characteristics of PLA, and this effect was weaker in PEG-containing formulations. The in vitro degradation study showed biodegradability, as a desirable property in wound dressing. Results suggested that higher degradation can be obtained by both plasticizers at the same time. The results also showed that PEG was more effective in enhancing water absorbency. In vitro drug release study indicated an explosive release and the highest amount was 85% over 186 h. The antibacterial activity test confirmed the effectiveness of the drug in preventing bacterial growth in the drug-containing formulations, while it showed the antibacterial property of TA. MTT assay was performed and the cellular toxicity of the formulations was checked and those that revealed the least toxicity were introduced.

Bioactive antibacterial bilayer PCL/gelatin nanofibrous scaffold promotes full-thickness wound healing

Treatment of diabetic, chronic, and full-thickness wounds is a challenge as these injuries usually lead to infections that cause delayed and inappropriate healing. Therefore, fabrication of skin scaffolds with prolonged antibacterial properties are of great interest. Due to this demand, bilayered nanofibrous scaffolds were fabricated based on polycaprolactone and gelatin. The top layer of these scaffolds contained amoxicillin as a model drug and the bottom layer was loaded with zinc oxide nanoparticles to accelerate wound healing. Several characterization techniques including FTIR, SEM, swelling, tensile test, in vitro degradation, drug release, antibacterial activity, and MTT assay were used to assess physical, mechanical, and biological properties of produced nanofibers. SEM results demonstrated that bilayered scaffolds have smooth bead-free microstructures while in vitro release test showed that samples have a sustained release for amoxicillin up to 144 h (tested time). Disk diffusion assessment confirmed the potency of scaffolds for hindering bacterial growth while results of cytotoxicity evaluation revealed that scaffolds could effectively accelerate cell proliferation. Finally, in vivo tests on full-thickness rat models revealed that fabricated nanofibers accelerate wound contraction, increase collagen deposition and angiogenesis, and prevent scar formation. Altogether, results showed that fabricated scaffolds are promising candidates for treatment of full-thickness wounds.

Electrospun Nano-Fibers for Biomedical and Tissue Engineering Applications: A Comprehensive Review

Pharmaceutical nano-fibers have attracted widespread attention from researchers for reasons such as adaptability of the electro-spinning process and ease of production. As a flexible method for fabricating nano-fibers, electro-spinning is extensively used. An electro-spinning unit is composed of a pump or syringe, a high voltage current supplier, a metal plate collector and a spinneret. Optimization of the attained nano-fibers is undertaken through manipulation of the variables of the process and formulation, including concentration, viscosity, molecular mass, and physical phenomenon, as well as the environmental parameters including temperature and humidity. The nano-fibers achieved by electro-spinning can be utilized for drug loading. The mixing of two or more medicines can be performed via electro-spinning. Facilitation or inhibition of the burst release of a drug can be achieved by the use of the electro-spinning approach. This potential is anticipated to facilitate progression in applications of drug release modification and tissue engineering (TE). The present review aims to focus on electro-spinning, optimization parameters, pharmacological applications, biological characteristics, and in vivo analyses of the electro-spun nano-fibers. Furthermore, current developments and upcoming investigation directions are outlined for the advancement of electro-spun nano-fibers for TE. Moreover, the possible applications, complications and future developments of these nano-fibers are summarized in detail.

Synthesis and characterization of antibacterial drug loaded β-tricalcium phosphate powders for bone engineering applications

Powders of β-tricalcium phosphate [β-TCP, β-Ca₃(PO₄)₂] and composite powders of β-TCP and polyvinyl alcohol (PVA) were synthesized by using wet precipitation methods. First, the conditions for the preparation of single phase β-TCP have been delineated. In the co-precipitation procedure, calcium nitrate and diammonium hydrogen phosphate were used as calcium and phosphorous precursors, respectively. The pH of the system was varied in the range 7-11 by adding designed amounts of ammonia solution. The filtered cakes were desiccated at 80 °C and subsequently calcined at different temperatures in the range between 700-1100 °C. Later on, rifampicin form II was used to produce drug-loaded β-TCP and PVA/β-TCP powders. All the synthesized materials have been characterized from morphological (by scanning electron microscopy) and structural-chemical (by X-ray diffraction and Fourier transform infrared spectroscopy) point of view. The drug loading capacity of the selected pure β-TCP powder has been assessed. The biological performance (cytocompatibility in fibroblast cell culture and antibacterial efficacy against Escherichia coli and Staphylococcus aureus) has been tested with promising results. Application perspectives of the designed drug-bioceramic-polymer blends are advanced and discussed.

Biopolymer-based biomaterials for accelerated diabetic wound healing: A critical review

Non-healing, chronic wounds place a huge burden on healthcare systems as well as individual patients. These chronic wounds especially diabetic wounds will ultimately lead to compromised mobility, amputation of limbs and even death. Currently, wounds and limb ulcers associated with diabetes remain significant health issues; the associated healthcare cost ultimately leads to the increased clinical burden. The presence of diabetes interrupts a highly coordinated cascade of events in the wound closure process. Advances in the understanding of pathophysiological conditions associated with diabetic wounds lead to the development of drug delivery systems which can enhance wound healing by targeting various phases of the impaired processes. Wound environments typically contain degradative enzymes, along with an elevated pH and demonstrate a physiological cascade involved in the regeneration of tissue, which requires the application of an effective delivery system. This article aims to review the pathophysiological conditions associated with chronic and diabetic wounds. The delivery systems, involved in their treatment are described, highlighting potential biomaterials and polymers for establishing drug delivery systems, specifically for the treatment of diabetic wounds and the promotion of the associated mechanisms involved in advanced wound healing. Emerging approaches and engineered devices for effective wound care are reported. The discussion will give insight into the mechanisms relevant to all stages of wound healing.

Drug Release Kinetics of Electrospun PHB Meshes

Microbial poly(3-hydroxybutyrate) (PHB) has several advantages including its biocompatibility and ability to degrade in vivo and in vitro without toxic substances. This paper investigates the feasibility of electrospun PHB meshes serving as drug delivery systems. The morphology of the electrospun samples was modified by varying the concentration of PHB in solution and the solvent composition. Scanning electron microscopy of the electrospun PHB scaffolds revealed the formation of different morphologies including porous, filamentous/beaded and fiber structures. Levofloxacin was used as the model drug for incorporation into PHB electrospun meshes. The entrapment efficiency was found to be dependent on the viscosity of the PHB solution used for electrospinning and ranged from 14.4–81.8%. The incorporation of levofloxacin in electrospun meshes was confirmed by Fourier-transform infrared spectroscopy and UV-VIS spectroscopy. The effect of the morphology of the electrospun meshes on the levofloxacin release profile was screened in vitro in phosphate-buffered saline solution. Depending upon the morphology, the electrospun meshes released about 14–20% of levofloxacin during the first 24 h. The percentage of drug released after 13 days increased up to 32.4% and was similar for all tested morphologies. The antimicrobial efficiency of all tested samples independent of the morphology, was confirmed by agar diffusion testing.

New Approach in Ulcer Prevention and Wound Healing Treatment using Doxycycline and Amoxicillin/LDH Nanocomposites

Doxycycline (DOX) and amoxicillin (AMOX) are important Broad-spectrum antibiotics used in treating multiple human and animal diseases. For the sake of exploring novel medical applications, both antibiotics were loaded into magnesium aluminium layer double hydroxide (Mg-Al)/LDH nanocomposite through the co-precipitation method. The synthesized materials were characterized by XRD, FT-IR, particle size analysis, FESEM and HRTEM. Acute toxicological studies were conducted using median lethal dose LD50, where a total number of 98 rats (200-150 gm) of both sexes were used. An experimental wound was aseptically incised on the anterior-dorsal side of each rat, while 98% of pure medical ethanol was used for ulcer induction. Acute toxicity, wound closure rate, healing percentages, ulcer index, protective rate and histopathological studies were investigated. Antibiotic Nanocomposites has significantly prevented ulcer formation and improved wound healing process to take shorter time than that of the typical processes, when compared with that of same drugs in microscale systems or commercial standard drugs. These results were confirmed by the histopathological findings. By converting it into the Nanoform, which is extremely important, especially with commonly used antibiotics, novel pharmacological properties were acquired from the antibiotics. The safe uses of DOX/LDH and AMOX/LDH Nanocomposites in this study were approved for biomedical applications.

Electrospun nanofibers as a wound dressing for treating diabetic foot ulcer

Diabetes is one of the most prevalent diseases in the world with high-mortality and complex complications including diabetic foot ulcer (DFU). It has been reported that the difficulties in repairing the wound related to DFU has much relationship with the wound infection, change of inflammatory responses, lack of extracellular matrix (ECM), and the failure of angiogenesis. Following the development of medical materials and pharmaceutical technology, nanofibers has been developed by electrospinning with huge porosity, excellent humidity absorption, a better oxygen exchange rate, and some antibacterial activities. That is to say, as a potential material, nanofibers must be a wonderful candidate for the DFU treatment with so many benefits. Careful selection of polymers from natural resource and synthetic resource can widen the nanofibrous application. Popular methods applied for the nanofibrous fabrication consist of uniaxial electrospinning and coaxial electrospinning. Furthermore, nanofibers loading chemical, biochemical active pharmaceutical ingredient (API) or even stem cells can be wonderful dosage forms for the treatment of DFU. This review summarizes the present techniques applied in the fabrication of nanofibrous dressing (ND) that utilizes a variety of materials and active agents to offer a better health care for the patients suffering from DFU.

Electrospinning of Highly Aligned Fibers for Drug Delivery Applications

Electrospinning is a straightforward, cost-effective, and versatile technique for fabrication of polymeric micro/nanofibers with tunable structural properties. Controlling the size, shape, and spatial orientation of the electrospun fibers is crucial for utilization in drug delivery and tissue engineering applications. In this study, for the first time, we systematically investigate the effect of processing parameters, including voltage, syringe needle gauge, angular velocity of rotating wheel, syringe-collector distance, and flow rate on the size and alignment of electrospun PLGA fibers. Optimizing these parameters enabled us to produce highly aligned and monodisperse PLGA fibers (spatial orientation> 99% and coefficient of variation< 0.5). To assess the effect of fiber alignment on the release of encapsulated drugs from these fibers, we incorporated dexamethasone, an anti-inflammatory drug, within highly-aligned and randomly-oriented fibers with comparable diameters (~0.87 μm) and compared their release profiles. In-vitro release studies revealed that the aligned fibers had less burst release (~10.8% in 24 hr) and more sustained release (~8.8% average rate of change for 24 days) compared to the random fibers. Finally, the degradation modes of the aligned and random fibers after 25 days incubation were characterized and compared. The findings of this study can be applied for the development of 3D degradable aligned fibers for controlled drug release and tissue engineering applications.

Novel Bacterial Cellulose-Poly (Acrylic Acid) Hybrid Hydrogels with Controllable Antimicrobial Ability as Dressings for Chronic Wounds

This investigation examines the combination of poly (acrylic acid) (PAA) and bacterial cellulose (BC) nanofibers to synthesize hydrogel hybrid composites used for wound dressing application. Amoxicillin (AM) was also grafted onto the composites for drug release. Fourier transform infrared analysis and scanning electron microscopy conducted revealed the structure and porosity of the composite being developed, as well as the successful fabrication of BC-PAA composites. The results of mechanical testing and hygroscopicity revealed that the composite shows higher stability than hydrogels which are currently used worldwide, albeit with a slight reduction in swelling capabilities. However, the composite was revealed to be responsive to a rise in pH values with an increase in composite swelling and drug release. These results together with their morphological characteristics suggest that BC-PAA hydrogel hybrid composite is a promising candidate for wound dressing application.

Artificial, Triple-Layered, Nanomembranous Wound Patch for Potential Diabetic Foot Ulcer Intervention

The present work aims to electrospin a triple layered wound patch for potential treatment of diabetic foot ulcers (DFU). The patch consisted of poly(acrylic acid) (PAA) as the skin contacting layer, polyvinyl pyrrolidone (PVP) as the middle layer, and polycaprolactone (PCL) as the outermost layer, wherein the PVP layer was loaded in situ with an antibiotic (ciprofloxacin, CFX). Morphology and mechanical properties were investigated using SEM and texture analysis. Patch quality was studied with regards to wettability, adherence, water resistance, and moisture uptake of individual layers. SEM results confirmed the fibrous and membranous nature of layers with a nano-to-micro size range. Mechanical properties of the composite patch demonstrated a tensile strength of 12.8 ± 0.5 MPa, deformation energy of 54.35 ± 0.1 J/m³, and resilience of 17.8 ± 0.7%, which were superior compared to individual layers. Patch quality tests revealed that the PCL layer showed very low wettability, adherence, and moisture uptake compared to the PVP and PAA layers. In vitro drug release data revealed an increase in cumulative drug release with higher drug loading. The results above confirm the potential of a triple layered, tripolymeric, wound patch for DFU intervention.

Development of Amoxicillin-Loaded Electrospun Polyurethane/Chitosan/ $\beta$ -Tricalcium Phosphate Scaffold for Bone Tissue Regeneration

Biocompatible nanocomposite electrospun fibers containing Polyurethane/Chitosan/ $\beta $ -Tri calcium phosphate with diverse concentrations were designed and produced through the electrospinning process for bone tissue engineering applications. After the production process, density measurement, viscosity, electrical conductivity, and tensile strength measurement tests were carried out as physical analyses of blended solutions. The chemical structural characterization was scrutinized using Fourier transform infrared spectrometer (FTIR), and scanning electron microscopy (SEM) was used to observe the morphological details of developed electrospun scaffolds. Cell viability, attachment, and proliferation were performed using a L929 fibroblast cell line. Based on the physical, SEM, FTIR analysis, and cell culture studies, preferable nanofiber composition was selected for further studies. Amoxicillin (AMX) was loaded to that selected nanofiber composition for examination of the drug release. In comparison with other studies on similar AMX controlled products, higher drug loading and encapsulation efficiencies were obtained. It has been clearly found that the developed nanofiber composites have potential for bone tissue engineering applications.

Electrospun polymeric nanofibres as wound dressings: A review

Skin wounds have significant morbidity and mortality rates associated. This is explained by the limited effectiveness of the currently available treatments, which in some cases do not allow the reestablishment of the structure and functions of the damaged skin, leading to wound infection and dehydration. These drawbacks may have an impact on the healing process and ultimately prompt patients' death. For this reason, researchers are currently developing new wound dressings that enhance skin regeneration. Among them, electrospun polymeric nanofibres have been regarded as promising tools for improving skin regeneration due to their structural similarity with the extracellular matrix of normal skin, capacity to promote cell growth and proliferation and bactericidal activity as well as suitability to deliver bioactive molecules to the wound site. In this review, an overview of the recent studies concerning the production and evaluation of electrospun polymeric nanofibrous membranes for skin regenerative purposes is provided. Moreover, the current challenges and future perspectives of electrospun nanofibrous membranes suitable for this biomedical application are highlighted.

Flexible Amoxicillin-Grafted Bacterial Cellulose Sponges for Wound Dressing: In Vitro and in Vivo Evaluation

In this study, we report the design and fabrication of a novel biocompatible sponge with excellent antibacterial property, making it a promising material for wound dressings. The sponge is formed by grafting amoxicillin onto regenerated bacterial cellulose (RBC). It was observed that the grafted RBC could enhance the antibacterial activity against fungus, Gram-negative, and Gram-positive bacteria. The morphology of strains treated with the grafted RBC and fluorescent stain results further demonstrated the antibacterial ability of the fabricated sponge. Moreover, a cytocompatibility test evaluated in vitro and in vivo illustrates the nontoxicity of the prepared sponge. More importantly, the wound infection model reveals that this sponge can accelerate the wound healing in vivo. This work indicates the novel sponge has the huge potential in wound dressing application for clinical use.

Preparation and Characterization of Porous Core-Shell Fibers for Slow Release of Tea Polyphenols

This study focused on the fabrication, characterization, and release properties of electrospun tea polyphenol (TPP) loaded porous core-shell structured fibers. The morphology, structure and properties of the electrospun TPP loaded porous core-shell fibers were investigated by a combination of Fourier transformation infrared spectroscopy (FTIR), scanning electron microscopy (SEM), contact angle (CA) measurements, transmission electron microscopy (TEM), etc. In addition, the cumulative drug release rate of TPP loaded porous core-shell fibers was determined by ultraviolet (UV) spectrophotometer, and the release mechanism was investigated using Fickian diffusion equation, which would provide the theoretical basis for future study. The results showed TPP loaded porous core-shell structured fibers were successfully prepared by coaxial electrospinning, and the porous structure of the core-shell fibers could further enlarge the specific surface area, enhance the hydrophobic properties, and improve the drug release properties.

Cilostazol-Loaded Poly(ε-Caprolactone) Electrospun Drug Delivery System for Cardiovascular Applications

PURPOSE

The study discusses the value of electrospun cilostazol-loaded (CIL) polymer structures for potential vascular implant applications.

METHODS

Biodegradable polycaprolactone (PCL) fibers were produced by electrospinning on a rotating drum collector. Three different concentrations of CIL: 6.25%, 12.50% and 18.75% based on the amount of polymer, were incorporated into the fibers. The fibers were characterized by their size, shape and orientation. Materials characterization was carried out by Fourier Transformed Infrared spectroscopy (FTIR), Raman spectroscopy, differential scanning calorimetry (DSC) and X-ray diffraction (XRD). In vitro drug release study was conducted using flow-through cell apparatus (USP 4).

RESULTS

Three-dimensional structures characterized by fibers diameter ranging from 0.81 to 2.48 μm were in the range required for cardiovascular application. DSC and XRD confirmed the presence of CIL in the electrospun fibers. FTIR and Raman spectra confirmed CIL polymorphic form. Elastic modulus values for PCL and the CIL-loaded PCL fibers were in the range from 0.6 to 1.1 GPa. The in vitro release studies were conducted and revealed drug dissolution in combination with diffusion and polymer relaxation as mechanisms for CIL release from the polymer matrix.

CONCLUSIONS

The release profile of CIL and nanomechanical properties of all formulations of PCL fibers demonstrate that the cilostazol loaded PCL fibers are an efficient delivery system for vascular implant application.

Functional electrospun fibers for the treatment of human skin wounds

Wounds are trauma induced defects of the human skin involving a multitude of endogenous biochemical events and cellular reactions of the immune system. The healing process is extremely complex and affected by the patient's physiological conditions, potential implications like infectious pathogens and inflammation as well as external factors. Due to increasing incidence of chronic wounds and proceeding resistance of infection pathogens, there is a strong need for effective therapeutic wound care. In this context, electrospun fibers with diameters in the nano- to micrometer range gain increasing interest. While resembling the structure of the native human extracellular matrix, such fiber mats provide physical and mechanical protection (including protection against bacterial invasion). At the same time, the fibers allow for gas exchange and prevent occlusion of the wound bed, thus facilitating wound healing. In addition, drugs can be incorporated within such fiber mats and their release can be adjusted by the material and dimensions of the individual fibers. The review gives a comprehensive overview about the current state of electrospun fibers for therapeutic application on skin wounds. Different materials as well as fabrication techniques are introduced including approaches for incorporation of drugs into or drug attachment onto the fiber surface. Against the background of wound pathophysiology and established therapy approaches, the therapeutic potential of electrospun fiber systems is discussed. A specific focus is set on interactions of fibers with skin cells/tissues as well as wound pathogens and strategies to modify and control them as key aspects for developing effective wound therapeutics. Further, advantages and limitations of controlled drug delivery from fiber mats to skin wounds are discussed and a future perspective is provided.

Drug loaded microbeads entrapped electrospun mat for wound dressing application

A new design of antibiotic loaded wound dressing and its initial in vitro evaluation is described. Chitosan microbeads loaded with ampicillin were sandwiched within polycaprolactone electrospun mat (MbAPPCL). The morphology was analyzed by scanning electron microscopy and surface chemistry was characterized by Fourier Transform Infrared Spectroscopy. In vitro cytotoxicity using L-929 fibroblast cells by direct contact test and elution assay revealed non-cytotoxic nature of MbAPPCL. The cell adhesion and viability analysis further confirmed the cytocompatibility of MbAPPCL as a wound dressing material. Percentage hemolysis and platelet adhesion on the mat exposed to blood substantiated the hemocompatibility. The antibiotic susceptibility test analyzed on Staphylococcus aureus by agar plate method confirmed the drug release and antimicrobial property. The proposed wound dressing model explained with ampicillin as a candidate drug has the potential to include microbeads with different antibiotics for multi drug treatment.

Nonwoven Polymer Nanofiber Coatings That Inhibit Quorum Sensing in Staphylococcus aureus: Toward New Nonbactericidal Approaches to Infection Control

We report the fabrication and biological evaluation of nonwoven polymer nanofiber coatings that inhibit quorum sensing (QS) and virulence in the human pathogen Staphylococcus aureus. Our results demonstrate that macrocyclic peptide 1, a potent and synthetic nonbactericidal quorum sensing inhibitor (QSI) in S. aureus, can be loaded into degradable polymer nanofibers by electrospinning and that this approach can deposit QSI-loaded nanofiber coatings onto model nonwoven mesh substrates. The QSI was released over ∼3 weeks when these materials were incubated in physiological buffer, retained its biological activity, and strongly inhibited agr-based QS in a GFP reporter strain of S. aureus for at least 14 days without promoting cell death. These materials also inhibited production of hemolysins, a QS-controlled virulence phenotype, and reduced the lysis of erythrocytes when placed in contact with wild-type S. aureus growing on surfaces. This approach is modular and can be used with many different polymers, active agents, and processing parameters to fabricate nanofiber coatings on surfaces important in healthcare contexts. S. aureus is one of the most common causative agents of bacterial infections in humans, and strains of this pathogen have developed significant resistance to conventional antibiotics. The QSI-based strategies reported here thus provide springboards for the development of new anti-infective materials and novel treatment strategies that target virulence as opposed to growth in S. aureus. This approach also provides porous scaffolds for cell culture that could prove useful in future studies on the influence of QS modulation on the development and structure of bacterial communities.

Agarose bioplastic-based drug delivery system for surgical and wound dressings

We have developed an agarose-based biocompatible drug delivery vehicle. The vehicle is in the form of thin, transparent, strong and flexible films. The biocompatibility and haemocompatibility of the films is confirmed using direct and indirect contact biological assay. Contact angle measurement exhibits hydrophilic nature of the films, and protein adsorption test shows low protein adsorption on the film surface. Drugs, antibiotics and antiseptics, retain their potency after their incorporation into the films. Our bioplastic films can be a versatile medium for drug delivery applications, especially as wound and surgical dressings where a fast drug release rate is desired.

Three-dimensional multilayered fibrous constructs for wound healing applications

Electrospun materials are promising scaffolds due to their light-weight, high surface-area and low-cost fabrication, however, such scaffolds are commonly obtained as ultrathin two-dimensional non-woven meshes, lacking on topographical specificity and surface side-dependent properties. Herein, it is reported the production of three-dimensional fibrous materials with an asymmetrical inner structure and engineered surfaces. The manufactured constructs evidence fibrous-based microsized conical protrusions [length: (10 ± 3) × 10(2) μm; width: (3.8 ± 0.8) × 10(2) μm] at their top side, with a median peak density of 73 peaks per cm(2), while their bottom side resembles to a non-woven mesh commonly observed in the fabrication of two-dimensional electrospun materials. Regarding their thickness (3.7 ± 0.1 mm) and asymmetric fibrous inner architecture, such materials avoid external liquid absorption while promoting internal liquid uptake. Nevertheless, such constructs also observed the high porosity (89.9%) and surface area (1.44 m(2) g(-1)) characteristic of traditional electrospun mats. Spray layer-by-layer assembly is used to effectively coat the structurally complex materials, allowing to complementary tailor features such as water vapor transmission, swelling ratio and bioactive agent release. Tested as wound dressings, the novel constructs are capable of withstanding (11.0 ± 0.3) × 10(4) kg m(-2) even after 14 days of hydration, while actively promote wound healing (90 ± 0.5% of wound closure within 48 hours) although avoiding cell adhesion on the dressings for a painless removal.

Electrospun Poly(lactide-co-glycolide-co-3(S)-methyl-morpholine-2,5-dione) Nanofibrous Scaffolds for Tissue Engineering

Biomimetic scaffolds have been investigated in vascular tissue engineering for many years. Excellent biodegradable materials are desired as temporary scaffolds to support cell growth and disappear gradually with the progress of guided tissue regeneration. In the present paper, a series of biodegradable copolymers were synthesized and used to prepared micro/nanofibrous scaffolds for vascular tissue engineering. Poly(lactide-co-glycolide-co-3(S)-methyl-morpholine-2,5-dione) [P(LA-co-GA-co-MMD)] copolymers with different l-lactide (LA), glycolide (GA), and 3(S)-methyl-2,5-morpholinedione (MMD) contents were synthesized using stannous octoate as a catalyst. Moreover, the P(LA-co-GA-co-MMD) nanofibrous scaffolds were prepared by electrospinning technology. The morphology of scaffolds was analyzed by scanning electron microscopy (SEM), and the results showed that the fibers are smooth, regular, and randomly oriented with diameters of 700 ± 100 nm. The weight loss of scaffolds increased significantly with the increasing content of MMD, indicating good biodegradable property of the scaffolds. In addition, the cytocompatibility of electrospun nanofibrous scaffolds was tested by human umbilical vein endothelial cells. It is demonstrated that the cells could attach and proliferate well on P(LA-co-GA-co-MMD) scaffolds and, consequently, form a cell monolayer fully covering on the scaffold surface. Furthermore, the P(LA-co-GA-co-MMD) scaffolds benefit to excellent cell infiltration after subcutaneous implantation. These results indicated that the P(LA-co-GA-co-MMD) nanofibrous scaffolds could be potential candidates for vascular tissue engineering.

Exploration of alginate hydrogel/nano zinc oxide composite bandages for infected wounds

Alginate hydrogel/zinc oxide nanoparticles (nZnO) composite bandage was developed by freeze-dry method from the mixture of nZnO and alginate hydrogel. The developed composite bandage was porous with porosity at a range of 60%–70%. The swelling ratios of the bandages decreased with increasing concentrations of nZnO. The composite bandages with nZnO incorporation showed controlled degradation profile and faster blood clotting ability when compared to the KALTOSTAT^® and control bandages without nZnO. The prepared composite bandages exhibited excellent antimicrobial activity against Escherichia coli, Staphylococcus aureus, Candida albicans, and methicillin resistant S. aureus (MRSA). Cytocompatibility evaluation of the prepared composite bandages done on human dermal fibroblast cells by Alamar assay and infiltration studies proved that the bandages have a non-toxic nature at lower concentrations of nZnO whereas slight reduction in viability was seen with increasing nZnO concentrations. The qualitative analysis of ex-vivo re-epithelialization on porcine skin revealed keratinocyte infiltration toward wound area for nZnO alginate bandages.

Electrospun Zein/PCL Fibrous Matrices Release Tetracycline in a Controlled Manner, Killing Staphylococcus aureus Both in Biofilms and Ex Vivo on Pig Skin, and are Compatible with Human Skin Cells

Purpose

To investigate the destruction of clinically-relevant bacteria within biofilms via the sustained release of the antibiotic tetracycline from zein-based electrospun polymeric fibrous matrices and to demonstrate the compatibility of such wound dressing matrices with human skin cells.

Methods

Zein/PCL triple layered fibrous dressings with entrapped tetracycline were electrospun. The successful entrapment of tetracycline in these dressings was validated. The successful release of bioactive tetracycline, the destruction of preformed biofilms, and the viability of fibroblast (FEK4) cells were investigated.

Results

The sustained release of tetracycline from these matrices led to the efficient destruction of preformed biofilms from Staphylococcus aureus MRSA252 in vitro, and of MRSA252 and ATCC 25923 bacteria in an ex vivo pig skin model using 1 × 1 cm square matrices containing tetracycline (30 μg). Human FEK4 cells grew normally in the presence of these matrices.

Conclusions

The ability of the zein-based matrices to destroy bacteria within increasingly complex in vitro biofilm models was clearly established. An ex vivo pig skin assay showed that these matrices, with entrapped tetracycline, efficiently kill bacteria and this, combined with their compatibility with a human skin cell line suggest these matrices are well suited for applications in wound healing and infection control.

Recent developments in novel drug delivery systems for wound healing

INTRODUCTION

Complete regeneration and restoration of the skin's structure and function with no or minimal scarring remains the goal of wound healing research. Novel pharmaceutical carriers have the potential to deliver wound healing drugs such as antibiotics, antimicrobials, human EGFs, and so on. Thus, offering a potential platform to overcome the limitations of conventional wound dressings.

AREAS COVERED

This review will describe various techniques such as microspheres, nanoparticles, liposomes, solid lipid nanoparticles, nano and microemulsions, sponges and wafers, and so on, that are successfully applied as carriers for wound healing drugs. Results of various studies including in vitro and in vivo experiments are also discussed.

EXPERT OPINION

Controlled and localized delivery of wound healing drugs to the wounds is more convenient than systemic administration as higher concentrations of the medication are delivered directly to the desired area in a sustained manner. They are also capable of providing optimum environmental conditions to facilitate wound healing while eliminating the need for frequent changes of dressings. As the number of people suffering from chronic wounds is increasing around the world, controlled delivery of wound healing agents have enormous potential for patient-friendly wound management.

Advances in skin regeneration: application of electrospun scaffolds

The paucity of cellular and molecular signals essential for normal wound healing makes severe dermatological ulcers stubborn to heal. The novel strategies of skin regenerative treatments are focused on the development of biologically responsive scaffolds accompanied by cells and multiple biomolecules resembling structural and biochemical cues of the natural extracellular matrix (ECM). Electrospun nanofibrous scaffolds provide similar architecture to the ECM leading to enhancement of cell adhesion, proliferation, migration and neo tissue formation. This Review surveys the application of biocompatible natural, synthetic and composite polymers to fabricate electrospun scaffolds as skin substitutes and wound dressings. Furthermore, the application of biomolecules and therapeutic agents in the nanofibrous scaffolds viz growth factors, genes, antibiotics, silver nanoparticles, and natural medicines with the aim of ameliorating cellular behavior, wound healing, and skin regeneration are discussed.

Nitrofurazone-loaded electrospun PLLA/sericin-based dual-layer fiber mats for wound dressing applications

Dual-layer nitrofurazone-loaded nanofiber mats are fabricated by electrospinning with good antibacterial activity and the mats perform well in wound healing.

Novel preparation of controlled porosity particle/fibre loaded scaffolds using a hybrid micro-fluidic and electrohydrodynamic technique

The purpose of this research was to produce multi-dimensional scaffolds containing biocompatible particles and fibres. To achieve this, two techniques were combined and used: T-Junction microfluidics and electrohydrodynamic (EHD) processing. The former was used to form layers of monodispersed bovine serum albumin (BSA) bubbles, which upon drying formed porous scaffolds. By altering the T-Junction processing parameters, bubbles with different diameters were produced and hence the scaffold porosity could be controlled. EHD processing was used to spray or spin poly(lactic-co-glycolic) (PLGA), polymethysilsesquioxane (PMSQ) and collagen particles/fibres onto the scaffolds during their production and after drying. As a result, multifunctional BSA scaffolds with controlled porosity containing PLGA, PMSQ and collagen particles/fibres were obtained. Product morphology was studied by optical and scanning electron microscopy. These products have potential applications in many advanced biomedical, pharmaceutical and cosmetic fields e.g. bone regeneration, drug delivery, cosmetic cream lathers, facial scrubbing creams etc.