Antimicrobial electrospun nanofibers of cellulose acetate and polyester urethane composite for wound dressing

A systematic review of liposomal nanofibrous scaffolds as a drug delivery system: a decade of progress in controlled release and therapeutic efficacy

Drug-loaded liposomes incorporated in nanofibrous scaffolds is a promising approach as a multi-unit nanoscale system, which combines the merits of both liposomes and nanofibers (NFs), eliminating the drawback of liposomes' poor stability on the one hand and offering a higher potential of controlled drug release and enhanced therapeutic efficacy on the other hand. The current systematic review, which underwent a rigorous search process in PubMed, Web of Science, Scopus, Embase, and Central (Cochrane) employing (Liposome AND nanofib* AND electrosp*) as search keywords, aims to present the recent studies on using this synergic system for different therapeutic applications. The search was restricted to original, peer-reviewed studies published in English between 2014 and 2024. Of the 309 identified records, only 29 studies met the inclusion criteria. According to the literature, three different methods were identified to fabricate those nanofibrous liposomal scaffolds. The results consistently demonstrated the superiority of this dual system for numerous therapeutic applications in improving the therapy efficacy, enhancing both liposomes and drug stability, and releasing the encapsulated drug in a proper sustained release without significant initial burst release. Merging drug-loaded liposomes with NFs as liposomal nanofibrous scaffolds are a safe and efficient approach to deliver drug molecules and other substances for various pharmaceutical applications, particularly for wound dressing, tissue engineering, cancer therapy, and drug administration via the buccal and sublingual routes. However, further research is warranted to explore the potential of this system in other therapeutic applications.

Cellulose-Based Nanofibers Infused with Biotherapeutics for Enhanced Wound-Healing Applications

Nanofibers fabricated from various materials such as polymers, carbon, and semiconductors have been widely used for wound healing and tissue engineering applications due to their excellent nontoxic, biocompatible, and biodegradable properties. Nanofibers with a diameter in the nanometer range possess a larger surface area per unit mass permitting easier addition of surface functionalities and release of biotherapeutics incorporated compared with conventional polymeric microfibers. Henceforth, nanofibers are a choice for fabricating scaffolds for the management of wound healing. Nanofibrous scaffolds have emerged as a promising method for fabricating wound dressings since they mimic the fibrous dermal extracellular matrix milieu that offers structural support for wound healing and functional signals for guiding tissue regeneration. Cellulose-based nanofibers have gained significant attention among researchers in the fabrication of on-site biodegradable scaffolds fortified with biotherapeutics in the management of wound healing. Cellulose is a linear, stereoregular insoluble polymer built from repeated units of d-glucopyranose linked with 1,4-β glycoside bonds with a complex and multilevel supramolecular architecture. Cellulose is a choice and has been used by various researchers due to its solubility in many solvents and its capacity for self-assembly into nanofibers, facilitating the mimicry of the natural extracellular matrix fibrous architecture and promoting substantial water retention. It is also abundant and demonstrates low immunogenicity in humans due to its nonanimal origins. To this end, cellulose-based nanofibers have been studied for protein delivery, antibacterial activity, and biosensor applications, among others. Taken together, this review delves into an update on cellulose-based nanofibers fused with bioactive compounds that have not been explored considerably in the past few years.

Cellulose Acetate Membranes: Antibacterial Strategy and Application-A Review

Developing antibacterial and biodegradable cellulose acetate (CA) membrane materials is one of the main challenges in multiple application fields. CA membrane materials are widely used in gas purification, water purification, and biomedical fields due to their environmental friendliness, high chemical and mechanical stability, excellent processability, and low cost. However, antibacterial modification of CA membrane materials to enhance their utilization value in the application process has always been the direction of researchers' efforts. This review focuses on the preparation and application of antibacterial CA and its derivatives membranes, especially the types and introduction methods of antibacterial agents. First, a brief introduction of CA-based polymer membranes is presented, followed by an overview of the antibacterial agent types and their introduction methods, and antibacterial mechanisms. After that, various membranes prepared using CA-based polymers as the main matrix or as additives are discussed. Then, specific applications of antibacterial CA-based membrane materials in water purification, gas purification, biomedical, food packaging, and other fields are outlined.

The impact of spatial structures of collagen on the hemostatic properties of collagen/calcium alginate composite membranes

Biomacromolecule-based hemostatic materials with biocompatibility and biodegradability have become a topic of significant research for the treatment of wound hemorrhage. Among available biomacromolecules, collagen and alginate are particularly promising. Although collagen and alginate composite materials have been developed, the impact of the spatial structures of collagen on the hemostatic properties of these materials remains to be fully understood. Collagen fibers, formed through self-assembly, share the same composition as collagen but exhibit distinct spatial structures. In this study, calcium alginate (CaAlg) membranes containing collagen (Col) or collagen fibers (Col-fiber) were fabricated. By adjusting the ratio of collagen to alginate, Col/CaAlg and Col-fiber/CaAlg composite membranes with favourable tensile strength and water retention ability were selected. The impact of collagen's spatial structures on the structures and properties of composite membranes was investigated, revealing that collagen fibers enhance the cytocompatibility, blood compatibility, and hemostatic performance of alginate membranes more effectively than collagen. Therefore, the Col-fiber/CaAlg membranes could be a promising candidate for hemostatic applications.

Synergetic effects of tetracycline hydrochloride incorporated regenerated cellulose acetate - Bacterial cellulose hybrid nanocomposite: Potential in biomedical application

Litter from cigarette waste is a significant threat to organisms and ecosystems. However, this waste contains cellulose acetate (CA) that can be recycled into raw materials. In this study, recycled CA from cigarettes (CFCA) electrospun through electro-spinning technique and developed hybrid nanocomposite by incorporating CFCA in the fermentation media, followed by self-assembly of bacterial cellulose (BC). CFCA exhibit excessive hydrophobicity due to their high crystallinity and reorientation of hydrophobic groups. We aimed to improve the hydrophilic, thermal and mechanical properties of CFCA. We examined fiber morphology using a scanning electron microscope (SEM), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction Analysis (XRD), thermogravimetric analysis (TGA), swelling capacity and mechanical properties. BC/CFCA showed higher swelling capacity, improved thermal properties, and good tensile strength compared to CFCA. Additionally, tetracycline hydrochloride (TC) was loaded into developed BC/CFCA matrix and evaluated in-vitro drug release, antibacterial activity and cytotoxicity. In-vitro drug release results showed that developed BC/CFCA can able to control TC release. In addition, prepared BC/CFCA-TC composites demonstrated excellent antibacterial activity against gram-positive and gram-negative bacteria. More importantly, BC/CFCA-TC composites exhibit good cytotoxicity on mouse fibroblast cells (L929). These characteristics of BC/CFCA-TC membranes indicate they may successfully serve as wound dressings and other medical biomaterials.

Silver nanoparticles loaded triple-layered cellulose-acetate based multifunctional dressing for wound healing

Chronic wounds present considerable challenges which delay their effective healing. Currently, there are several biomaterial-based wound dressings available for healing diverse wound types. However, most of commercial wound dressings are too expensive to be affordable to the patients belonging to the middle and lower socioeconomic strata of the society. Thus, in this investigation affordable triple layered nanofibrous bandages were fabricated using the layer-by-layer approach. Here, the topmost layer comprised of a hydrophilic poly vinyl alcohol layer, cross-linked with citric acid. The middle layer comprising of cellulose acetate was loaded with silver nanoparticles as an antibacterial agent, while the lowermost layer was fabricated using hydrophobic polycaprolactone. The triple-layered nanofibrous bandages having a nano-topography, exhibited a smooth, uniform and bead-free morphology, with the nanofiber diameter ranging between 200 and 300 nm. The nanofibers demonstrated excellent wettability, slow in vitro degradation, controlled release of nano‑silver and potent antibacterial activity against Gram-negative (E.coli) and Gram-positive (S. aureus) bacteria. The fabricated bandages had excellent mechanical strength upto 12.72 ± 0.790 M. Pa, which was suitable for biomedical and tissue engineering applications. The bandage demonstrated excellent in vitro hemocompatibility and biocompatibility. In vivo excisional wound contraction, along with H and E and Masson's Trichrome staining further confirmed the potential of the nanofibrous bandage for full-thickness wound healing. Pre-clinical investigations thus indicated the possibility of further evaluating the triple-layered nanofibrous dressing in clinical settings.

Cancer Treatment Using Nanofibers: A Review

Currently, the number of patients with cancer is expanding consistently because of a low quality of life. For this reason, the therapies used to treat cancer have received a lot of consideration from specialists. Numerous anticancer medications have been utilized to treat patients with cancer. However, the immediate utilization of anticancer medicines leads to unpleasant side effects for patients and there are many restrictions to applying these treatments. A number of polymers like cellulose, chitosan, Polyvinyl Alcohol (PVA), Polyacrylonitrile (PAN), peptides and Poly (hydroxy alkanoate) have good properties for the treatment of cancer, but the nanofibers-based target and controlled drug delivery system produced by the co-axial electrospinning technique have extraordinary properties like favorable mechanical characteristics, an excellent release profile, a high surface area, and a high sponginess and are harmless, bio-renewable, biofriendly, highly degradable, and can be produced very conveniently on an industrial scale. Thus, nanofibers produced through coaxial electrospinning can be designed to target specific cancer cells or tissues. By modifying the composition and properties of the nanofibers, researchers can control the release kinetics of the therapeutic agent and enhance its accumulation at the tumor site while minimizing systemic toxicity. The core-shell structure of coaxial electrospun nanofibers allows for a controlled and sustained release of therapeutic agents over time. This controlled release profile can improve the efficacy of cancer treatment by maintaining therapeutic drug concentrations within the tumor microenvironment for an extended period.

Reinforcing decellularized small intestine submucosa with cellulose acetate nanofibrous and silver nanoparticles as a scaffold for wound healing applications

BACKGROUND

The formation of chronic wounds accounts for considerable costs in health care systems. Despite the several benefits of decellularized small intestinal submucosa (SIS) as an appropriate scaffold for different tissue regeneration, it has shortcomings such as lack of antibacterial features and inappropriate mechanical properties for skin tissue regeneration. We aimed to examine the efficacy and safety of decellularized SIS scaffold enhanced with cellulose acetate (CA) and silver (Ag) nanoparticles (NPs) for healing full-thickness wounds.

METHODS AND RESULTS

The scaffolds were prepared by decellularizing bovine SIS and electrospinning CA/Ag nanoparticles and characterized using a transmission electron microscope (TEM), scanning electron microscope (SEM), tensile testing, and X-ray diffraction. In vivo evaluations were performed using full-thickness excisions covered with sterile gauze as the control group, SIS, SIS/CA, and SIS/CA/Ag scaffolds on the dorsum of twenty male Wistar rats divided into four groups randomly with 21-days follow-up. All in vivo specimens underwent Masson's trichrome (MT) staining for evaluation of collagen deposition, transforming growth factor-β (TGF-β) immunohistochemistry (IHC), and Haematoxylin Eosin (H&E) staining. The IHC and MT data were analyzed with the ImageJ tool by measuring the stained area. The TEM results revealed that Ag nanoparticles are successfully incorporated into CA nanofibers. Assessment of scaffolds hydrophilicity demonstrated that the contact angle of SIS/CA/Ag scaffold was the lowest. The in vivo results indicated that the SIS/CA/Ag scaffold had the most significant wound closure. H&E staining of the in vivo specimens showed the formation of epidermal layers in the SIS/CA/Ag group on day 21. The percentage of the stained area of MT and TGF-β IHC staining's was highest in the SIS/CA/Ag group.

CONCLUSION

The decellularized SIS/CA/Ag scaffolds provided the most significant wound closure compared to other groups and caused the formation of epidermal layers and skin appendages. Additionally, the collagen deposition and expression of TGF-β increased significantly in SIS/CA/Ag group.

Pharmaceutical/Biomedical Applications of Electrospun Nanofibers - Comprehensive Review, Attentive to Process Parameters and Patent Landscape

Nanotechnology is a new science and business endeavour with worldwide economic benefits. Growing knowledge of nanomaterial fabrication techniques has increased the focus on nanomaterial preparation for various purposes. Nanofibers are one-dimensional nanomaterials having distinct physicochemical properties and characteristics. Nanofibers are nanomaterial types with a cross-sectional dimension of tens to hundreds of nanometres. They may create high porosity mesh networks with significant interconnections among pores, making them suitable for advanced applications. Electrospinning stands out for its ease of use, flexibility, low cost, and variety among the approaches described in the literature. The most common method for making nanofibers is electrospinning. This article extensively describes and summarizes the impact of various process variables on the fabrication of nanofibers. Special attention has been given to scientific and patent prospection to confirm the research interests in nanofibers.

Three-Dimensional Printed Cellulose for Wound Dressing Applications

Wounds are skin tissue damage due to trauma. Many factors inhibit the wound healing phase (hemostasis, inflammation, proliferation, and alteration), such as oxygenation, contamination/infection, age, effects of injury, sex hormones, stress, diabetes, obesity, drugs, alcoholism, smoking, nutrition, hemostasis, debridement, and closing time. Cellulose is the most abundant biopolymer in nature which is promising as the main matrix of wound dressings because of its good structure and mechanical stability, moisturizes the area around the wound, absorbs excess exudate, can form elastic gels with the characteristics of bio-responsiveness, biocompatibility, low toxicity, biodegradability, and structural similarity with the extracellular matrix (ECM). The addition of active ingredients as a model drug helps accelerate wound healing through antimicrobial and antioxidant mechanisms. Three-dimensional (3D) bioprinting technology can print cellulose as a bioink to produce wound dressings with complex structures mimicking ECM. The 3D printed cellulose-based wound dressings are a promising application in modern wound care. This article reviews the use of 3D printed cellulose as an ideal wound dressing and their properties, including mechanical properties, permeability aspect, absorption ability, ability to retain and provide moisture, biodegradation, antimicrobial property, and biocompatibility. The applications of 3D printed cellulose in the management of chronic wounds, burns, and painful wounds are also discussed.

Regeneration and modification of cellulose acetate from cigarette waste: Biomedical potential by encapsulation of tetracycline hydrochloride

Cigarette waste are pervasive litter on Earth, posing a major threat to organisms and ecosystems. However, these waste contain cellulose acetate (CA) and can be recycled, transforming into raw materials for new products. Polymers like CA can be used in biomedical applications as drug carriers and scaffolds for drug release. In this study, cigarette filters waste was collected, recycled and used for fabricating the nanofibrous membrane of cellulose acetate nanofibers (CFCA) through electrospinning technique. Tetracycline hydrochloride (TC) was encapsulated in the nanofibers to prevent bacterial infections. Various analyses were conducted: Scanning Electron Microscope (SEM), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction Analysis (XRD) and Thermogravimetric analysis (TGA). CA and CFCA exhibited high water uptake properties and exhibited similar breaking stress and strain values. Both CA and CFCA effectively acted as stable drug carriers, with sustained in vitro drug release. Antibacterial activity was demonstrated by the drug-loaded CA and CFCA nanofibers against, Gram-positive bacteria Staphylococcus aureus and Gram-negative bacteria Escherichia coli. Based on their cytotoxicity evaluations on mouse fibroblast cells (L929), CA and CFCA fibrous mats demonstrated no cytotoxicity and similar cell viability results. Consequently, the TC-loaded nanofibers made from CA and CFCA exhibited suitable properties for wound healing applications.

Chlorhexidine-Containing Electrospun Polymeric Nanofibers for Dental Applications: An In Vitro Study

Chlorhexidine is the most commonly used anti-infective drug in dentistry. To treat infected void areas, a drug-loaded material that swells to fill the void and releases the drug slowly is needed. This study investigated the encapsulation and release of chlorhexidine from cellulose acetate nanofibers for use as an antibacterial treatment for dental bacterial infections by oral bacteria Streptococcus mutans and Enterococcus faecalis. This study used a commercial electrospinning machine to finely control the manufacture of thin, flexible, chlorhexidine-loaded cellulose acetate nanofiber mats with very-small-diameter fibers (measured using SEM). Water absorption was measured gravimetrically, drug release was analyzed by absorbance at 254 nm, and antibiotic effects were measured by halo analysis in agar. Slow electrospinning at lower voltage (14 kV), short target distance (14 cm), slow traverse and rotation, and syringe injection speeds with controlled humidity and temperature allowed for the manufacture of strong, thin films with evenly cross-meshed, uniform low-diameter nanofibers (640 nm) that were flexible and absorbed over 600% in water. Chlorhexidine was encapsulated efficiently and released in a controlled manner. All formulations killed both bacteria and may be used to fill infected voids by swelling for intimate contact with surfaces and hold the drug in the swollen matrix for effective bacterial killing in dental settings.

Cellulose-based bioabsorbable and antibiotic coated surgical staple with bioinspired design for efficient wound closure

The quest to design a flawless wound closure system began long ago and is still underway. Introducing surgical staples is one of the most significant breakthroughs in this effort. In this work, we developed a biodegradable surgical staple to meet the optimal wound closure system criteria and other clinical requirements, such as radiography compatibility and secondary infection prevention. To meet these requirements, a naturally derived cellulose acetate (CA) fiber-reinforced poly-(l-lactic acid) (PLLA) composite was synthesized, and its physicochemical properties were determined using several characterizations such as Fourier-transform infrared spectroscopy (FTIR), Differential scanning calorimetry (DSC) and Universal testing machine (UTM), etc. Taking cues from the Mantis's foreleg, a novel staple design was implemented and verified using Finite Element Analysis (FEA). The CA + PLLA staples were fabricated using melt-casted/3D-printing processes. The staples exhibited excellent biodegradation in both wound and physiological microenvironments with sufficient puncturing strength and later closed the wound's edges mechanically. In addition, the CA + PLLA staples also exhibit metal-like ductility properties to withstand horizontal skin tensions during the healing process. Further, the staples are coated with an antibiotic to combat infections effectively to provide better healing.

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.

Fabrication of hierarchical porous ethyl cellulose fibrous membrane by electro-centrifugal spinning for drug delivery systems with excellent integrated properties

Drug delivery systems (DDSs) based on micro-and nano- fibrous membrane have been developed for decades, in which great attention has been focused on achieving controlled drug release. However, the study on the integrated performance of these drug-loaded membranes in the use of in-vitro drug delivery dressing is lacking, as clinical medication also needs consideration from the perspectives of wound safety and patient convenience. Herein, a trilayered hierarchical porous ethyl cellulose (EC) fibrous membrane based DDS (EC-DDS) was developed by electro-centrifugal spinning. Significantly, the hierarchical porous structure of the EC-DDSs with high specific surface area (34.3 m²g^-1) and abundant long-regulative micro-and nano- channels demonstrated its merits in improving the hydrophobicity (long-term splash resistance (CA > 130°) and prolonging the drug release (the release time of ~80 % tetracycline hydrochloride (TCH) prolonged from 10 min to 24 h). Meanwhile, the trilayered EC-DDS also revealed excellent biocompatibility, antibacterial activity, air permeability, moisture permeability, water absorption capacity, mechanical strength, and flexibility. With these excellent integrated features, the EC-DDS could prevent external fluids, avoid infection, and provide comfort. Furthermore, this work also provides a new guide for the high-efficiency fabrication of porous fibrous membranes.

A Schiff base hydrogel dressing loading extracts from Periplaneta Americana for diabetic wound healing

As a common complication of diabetic patients, the chronic wound of diabetes has a high incidence, expensive treatment, and recurrence probability, which causes long-term negative impacts on patients' daily life. In this study, the hydrogel was formed by Schiff base reaction between oxidized hyaluronic acid (OHA) and carboxymethyl chitosan (CMCS), and the composite hydrogel dressing was prepared by adding the active polypeptides extract of Periplaneta Americana (PAE). By mass spectrometer determined, PAE mainly includes vitellogenins that can trigger an immune response. The composite hydrogel has good swelling properties, proper fluidity, and a regular 3D network structure. The hydrogel has good cytocompatibility and can promote cell proliferation by L929 fibroblast assay. Finally, it was used to evaluate the effect of diabetic wound repair. The results showed that it could effectively promote wound healing, promote tissue and vascular regeneration, inhibit inflammatory factors, and promote the expression of growth factors. The OHA/CMCS/PAE hydrogels would be promising candidates for chronic wound healing applications.

Biodegradable Electrospun Scaffolds as an Emerging Tool for Skin Wound Regeneration: A Comprehensive Review

Skin is designed to protect various tissues, and because it is the largest and first human bodily organ to sustain damage, it has an incredible ability to regenerate. On account of extreme injuries or extensive surface loss, the normal injury recuperating interaction might be inadequate or deficient, bringing about risky and disagreeable circumstances that request the utilization of fixed adjuvants and tissue substitutes. Due to their remarkable biocompatibility, biodegradability, and bioactive abilities, such as antibacterial, immunomodulatory, cell proliferative, and wound mending properties, biodegradable polymers, both synthetic and natural, are experiencing remarkable progress. Furthermore, the ability to convert these polymers into submicrometric filaments has further enhanced their potential (e.g., by means of electrospinning) to impersonate the stringy extracellular grid and permit neo-tissue creation, which is a basic component for delivering a mending milieu. Together with natural biomaterial, synthetic polymers are used to solve stability problems and make scaffolds that can dramatically improve wound healing. Biodegradable polymers, commonly referred to as biopolymers, are increasingly used in other industrial sectors to reduce the environmental impact of material and energy usage as they are fabricated using renewable biological sources. Electrospinning is one of the best ways to fabricate nanofibers and membranes that are very thin and one of the best ways to fabricate continuous nanomaterials with a wide range of biological, chemical, and physical properties. This review paper concludes with a summary of the electrospinning (applied electric field, needle-to-collector distance, and flow rate), solution (solvent, polymer concentration, viscosity, and solution conductivity), and environmental (humidity and temperature) factors that affect the production of nanofibers and the use of bio-based natural and synthetic electrospun scaffolds in wound healing.

Polyurethane and cellulose acetate micro-nanofibers containing rosemary essential oil, and decorated with silver nanoparticles for wound healing application

In this study, polyurethane (PU) and cellulose acetate (CA) electrospun fibers encapsulating rosemary essential oil (REO) and adsorbed silver (Ag) nanoparticles (NPs) were fabricated. The biologically inspired materials were analyzed for physicochemical characteristics using scanning electron microscopy, X-ray diffractometer, Fourier transform infrared, thermal gravimetric analysis, X-ray photoelectron spectroscopy, water contact angle, and water uptake studies. Results confirmed the presence of CA and Ag NPs on the PU micro-nanofibers increased the hydrophilicity from 107.1 ± 0.36^o to 26.35 ± 1.06^o. The water absorption potential increased from 0.07 ± 0.04 for pristine PU fibers to 12.43 ± 0.49 % for fibers with 7 wt% of CA, REO, and Ag NPs. The diffractometer confirmed the 2θ of 38.01°, 44.13^o, and 64.33^o, corresponding to the diffraction planes of Ag on the fibers. The X-ray photoelectron spectroscopy confirmed microfibers interfacial chemical interaction and surface changes due to CA, REO, and Ag presence. The inhibition tests on Staphylococcus aureus and Escherichia coli indicated that composites are antibacterial in activity. Moreover, synergistic interactions of REO and Ag NPs resulted in superior antibacterial activity. The cell viability and attachment assay showed improved hydrophilicity of the fibers, which resulted in better attachment of cells to the micro-nanofibers, similar to the natural extracellular matrix in the human body.

Magnetic fields enable precise spatial control over electrospun fiber alignment for fabricating complex gradient materials

Musculoskeletal interfacial tissues consist of complex gradients in structure, cell phenotype, and biochemical signaling that are important for function. Designing tissue engineering strategies to mimic these types of gradients is an ongoing challenge. In particular, new fabrication techniques that enable precise spatial control over fiber alignment are needed to better mimic the structural gradients present in interfacial tissues, such as the tendon-bone interface. Here, we report a modular approach to spatially controlling fiber alignment using magnetically-assisted electrospinning. Electrospun fibers were highly aligned in the presence of a magnetic field and smoothly transitioned to randomly aligned fibers away from the magnetic field. Importantly, magnetically-assisted electrospinning allows for spatial control over fiber alignment at sub-millimeter resolution along the length of the fibrous scaffold similar to the native structural gradient present in many interfacial tissues. The versatility of this approach was further demonstrated using multiple electrospinning polymers and different magnet configurations to fabricate complex fiber alignment gradients. As expected, cells seeded onto gradient fibrous scaffolds were elongated and aligned on the aligned fibers and did not show a preferential alignment on the randomly aligned fibers. Overall, this fabrication approach represents an important step forward in creating gradient fibrous materials, where such materials are promising as tissue-engineered scaffolds for regenerating functional musculoskeletal interfacial tissues.

Therapeutic applications of electrospun nanofibers impregnated with various biological macromolecules for effective wound healing strategy - A review

A Non-healing infected wound is an ever-growing global epidemic, with increasing burden of mortality rates and management costs. The problems of chronic wound infections and their outcomes will continue as long as their underlying causes like diabetic wounds grow and spread. Commercial wound therapies employed have limited potential that inhibits pivotal functions and tissue re-epithelialization properties resulting in wound infections. Nanomaterial based drug delivery formulations involving biological macromolecules are developing areas of interest in wound healing applications which are utilized in the re-epithelialization of skin with cost-effective preparations. Research conducted on nanofibers has shown enhanced skin establishment with improved cell proliferation and growth and delivery of bioactive organic molecules at the wound site. However, drug targeted delivery with anti-scarring properties and tissue regeneration aspects have not been updated and discussed in the case of macromolecule impregnated nanofibrous mats. Hence, this review focuses on the brief concepts of wound healing and wound management, therapeutic commercialized wound dressings currently available in the field of wound care, effective electrospun nanofibers impregnated with different biological macromolecules and advancement of nanomaterials for tissue engineering have been discussed. These new findings will pave the way for producing anti-scarring high effective wound scaffolds for drug delivery.

Polyhexanide-Releasing Membranes for Antimicrobial Wound Dressings: A Critical Review

The prevalence of chronic, non-healing skin wounds in the general population, most notably diabetic foot ulcers, venous leg ulcers and pressure ulcers, is approximately 2% and is expected to increase, driven mostly by the aging population and the steady rise in obesity and diabetes. Non-healing wounds often become infected, increasing the risk of life-threatening complications, which poses a significant socioeconomic burden. Aiming at the improved management of infected wounds, a variety of wound dressings that incorporate antimicrobials (AMDs), namely polyhexanide (poly(hexamethylene biguanide); PHMB), have been introduced in the wound-care market. However, many wound-care professionals agree that none of these wound dressings show comprehensive or optimal antimicrobial activity. This manuscript summarizes and discusses studies on PHMB-releasing membranes (PRMs) for wound dressings, detailing their preparation, physical properties that are relevant to the context of AMDs, drug loading and release, antibacterial activity, biocompatibility, wound-healing capacity, and clinical trials conducted. Some of these PRMs were able to improve wound healing in in vivo models, with no associated cytotoxicity, but significant differences in study design make it difficult to compare overall efficacies. It is hoped that this review, which includes, whenever available, international standards for testing AMDs, will provide a framework for future studies.

Modifications of cellulose-based biomaterials for biomedical applications

Cellulose is one of the most abundant organic compounds in nature and is available from diverse sources. Cellulose features tunable properties, making it a promising substrate for biomaterial development. In this review, we highlight advances in the physical processes and chemical modifications of cellulose that enhance its properties for use as a biomaterial. Three cellulosic products are discussed, including nanofibrillated, nanocrystalline, and bacterial cellulose, with a focus on how each may serve as a platform for the development of advanced cellulose-based biomaterials for Biomedical applications. In addition to associating mechanical and chemical properties of cellulosic materials to specific applications, a prospectus is offered for the future development of cellulose-based biomaterials for biomedicine.

Natural protein-based electrospun nanofibers for advanced healthcare applications: progress and challenges

Electrospinning is an electrostatic fiber fabrication technique that operates by the application of a strong electric field on polymer solution or melts. It is used to fabricate fibers whose size lies in the range of few microns to the nanometer range. Historic development of electrospinning has evinced attention due to its outstanding attributes such as small diameter, excellent pore inter-connectivity, high porosity, and high surface-to-volume ratio. This review aims to highlight the theory behind electrospinning and the machine setup with a detailed discussion about the processing parameters. It discusses the latest innovations in natural protein-based electrospun nanofibers for health care applications. Various plant- and animal-based proteins have been discussed with detailed sample preparation and corresponding processing parameters. The usage of these electrospun nanofibers in regenerative medicine and drug delivery has also been discussed. Some technical innovations in electrospinning techniques such as emulsion electrospinning and coaxial electrospinning have been highlighted. Coaxial electrospun core-shell nanofibers have the potential to be utilized as an advanced nano-architecture for sustained release targeted delivery as well as for regenerative medicine. Healthcare applications of nanofibers formed via emulsion and coaxial electrospinning have been discussed briefly. Electrospun nanofibers have still much scope for commercialization on large scale. Some of the available wound-dressing materials have been discussed in brief.

Nanoengineered therapeutic scaffolds for burn wound management

BACKGROUND

Wound healing is a complex process, and selecting an appropriate treatment is crucial and varies from one wound to another. Among injuries, burn wounds are more challenging to treat. Different dressings and scaffolds come into play when skin is injured. These scaffolds provide the optimum environment for wound healing. With the advancements of nanoengineering, scaffolds have been engineered to improve wound healing with lower fatality rates.

OBJECTIVES

Nanoengineered systems have emerged as one of the promising candidates for burn wound management. This review paper aims to provide an in-depth understanding of burn wounds and the role of nanoengineering in burn wound management. The advantages of nanoengineered scaffolds, their properties, and their proven effectiveness have been discussed. Nanoparticles and nanofibers-based nanoengineered therapeutic scaffolds provide optimum protection, infection management, and accelerated wound healing due to their unique characteristics. These scaffolds increase cell attachment and proliferation for desired results.

RESULTS

The literature review suggested that the utilization of nanoengineered scaffolds has accelerated burn wound healing. Nanofibers provide better cell attachment and proliferation among different nanoengineered scaffolds due to their 3D structure mimics the body's extracellular matrix.

CONCLUSION

With the application of these advanced nanoengineered scaffolds, better burn wound management is possible due to sustained drug delivery, better cell attachment, and an infection-free environment.

Electrospun Nanofibers Revisited: An Update on the Emerging Applications in Nanomedicine

Electrospinning (ES) has become a straightforward and customizable drug delivery technique for fabricating drug-loaded nanofibers (NFs) using various biodegradable and non-biodegradable polymers. One of NF's pros is to provide a controlled drug release through managing the NF structure by changing the spinneret type and nature of the used polymer. Electrospun NFs are employed as implants in several applications including, cancer therapy, microbial infections, and regenerative medicine. These implants facilitate a unique local delivery of chemotherapy because of their high loading capability, wide surface area, and cost-effectiveness. Multi-drug combination, magnetic, thermal, and gene therapies are promising strategies for improving chemotherapeutic efficiency. In addition, implants are recognized as an effective antimicrobial drug delivery system overriding drawbacks of traditional antibiotic administration routes such as their bioavailability and dosage levels. Recently, a sophisticated strategy has emerged for wound healing by producing biomimetic nanofibrous materials with clinically relevant properties and desirable loading capability with regenerative agents. Electrospun NFs have proposed unique solutions, including pelvic organ prolapse treatment, viable alternatives to surgical operations, and dental tissue regeneration. Conventional ES setups include difficult-assembled mega-sized equipment producing bulky matrices with inadequate stability and storage. Lately, there has become an increasing need for portable ES devices using completely available off-shelf materials to yield highly-efficient NFs for dressing wounds and rapid hemostasis. This review covers recent updates on electrospun NFs in nanomedicine applications. ES of biopolymers and drugs is discussed regarding their current scope and future outlook.

The latest achievements in plant cellulose-based biomaterials for tissue engineering focusing on skin repair

The present work reviews recent developments in plant cellulose-based biomaterial design and applications, properties, characterizations, and synthesis for skin tissue engineering and wound healing. Cellulose-based biomaterials are promising materials for their remarkable adaptability with three-dimensional polymeric structure. They are capable of mimicking tissue properties, which plays a key role in tissue engineering. Besides, concerns for environmental issues have motivated scientists to move toward eco-friendly materials and natural polymer-based materials for applications in the tissue engineering field these days. Therefore, cellulose as an appropriate substitute for common polymers based on crude coal, animal, and human-derived biomolecules is greatly considered for various applications in biomedical fields. Generally, natural biomaterials lack good mechanical properties for skin tissue engineering. But using modified cellulose-based biopolymers tackles these restrictions and prevents immunogenic responses. Moreover, tissue engineering is a quick promoting field focusing on the generation of novel biomaterials with modified characteristics to improve scaffold function through physical, biochemical, and chemical tailoring. Also, nanocellulose with a broad range of applications, particularly in tissue engineering, advanced wound dressing, and as a material for coupling with drugs and sensorics, has been reviewed here. Moreover, the potential cytotoxicity and immunogenicity of cellulose-based biomaterials are addressed in this review.

Enhanced mechanical performance and wettability of PHBV fiber blends with evening primrose oil for skin patches improving hydration and comfort

The growing problem of skin diseases due to allergies causing atopic dermatitis, which is characterized by itching, burning, and redness, constantly motivates researchers to look for solutions to soothe these effects by moisturizing skin properly.

Electrospun Antibacterial Nanomaterials for Wound Dressings Applications

Chronic wounds are caused by bacterial infections and create major healthcare discomforts; to overcome this issue, wound dressings with antibacterial properties are to be utilized. The requirements of antibacterial wound dressings cannot be fulfilled by traditional wound dressing materials. Hence, to improve and accelerate the process of wound healing, an antibacterial wound dressing is to be designed. Electrospun nanofibers offer a promising solution to the management of wound healing, and numerous options are available to load antibacterial compounds onto the nanofiber webs. This review gives us an overview of some recent advances of electrospun antibacterial nanomaterials used in wound dressings. First, we provide a brief overview of the electrospinning process of nanofibers in wound healing and later discuss electrospun fibers that have incorporated various antimicrobial agents to be used in wound dressings. In addition, we highlight the latest research and patents related to electrospun nanofibers in wound dressing. This review also aims to concentrate on the importance of nanofibers for wound dressing applications and discuss functionalized antibacterial nanofibers in wound dressing.

Hemostatic materials in wound care

Blood plays an essential role in the human body. Hemorrhage is a critical cause of both military and civilian casualties. The human body has its own hemostatic mechanism that involves complex processes and has limited capacity. However, in emergency situations such as battlefields and hospitals, when the hemostatic mechanism of the human body itself cannot stop bleeding effectively, hemostatic materials are needed for saving lives. In this review, the hemostatic mechanisms and performance of the most commonly used hemostatic materials, (including fibrin, collagen, zeolite, gelatin, alginate, chitosan, cellulose and cyanoacrylate) and the commercial wound dressings based on these materials, will be discussed. These materials may have limitations, such as poor tissue adhesion, risk of infection and exothermic reactions, that may lessen their hemostatic efficacy and cause secondary injuries. High-performance hemostatic materials, therefore, have been designed and developed to improve hemostatic efficiency in clinical use. In this review, hemostatic materials with advanced performances, such as antibacterial capacity, superhydrophobicity/superhydrophilicity, superelasticity, high porosity and/or biomimicry, will be introduced. Future prospects of hemostatic materials will also be discussed in this review.

Photocatalytic Nanofiber Membranes for the Degradation of Micropollutants and Their Antimicrobial Activity: Recent Advances and Future Prospects

This review paper systematically evaluates current progress on the development and performance of photocatalytic nanofiber membranes often used in the removal of micropollutants from water systems. It is demonstrated that nanofiber membranes serve as excellent support materials for photocatalytic nanoparticles, leading to nanofiber membranes with enhanced optical properties, as well as improved recovery, recyclability, and reusability. The tremendous performance of photocatalytic membranes is attributed to the photogenerated reactive oxygen species such as hydroxyl radicals, singlet oxygen, and superoxide anion radicals introduced by catalytic nanoparticles such as TiO₂ and ZnO upon light irradiation. Hydroxyl radicals are the most reactive species responsible for most of the photodegradation processes of these unwanted pollutants. The review also demonstrates that self-cleaning and antimicrobial nanofiber membranes are useful in the removal of microbial species in water. These unique materials are also applicable in other fields such as wound dressing since the membrane allows for oxygen flow in wounds to heal while antimicrobial agents protect wounds against infections. It is demonstrated that antimicrobial activities against bacteria and photocatalytic degradation of micropollutants significantly reduce membrane fouling. Therefore, the review demonstrates that electrospun photocatalytic nanofiber membranes with antimicrobial activity form efficient cost-effective multifunctional composite materials for the removal of unwanted species in water and for use in various other applications such as filtration, adsorption and electrocatalysis.

Recent Advances in Cellulose-Based Structures as the Wound-Healing Biomaterials: A Clinically Oriented Review

Application of wound-healing/dressing biomaterials is amongst the most promising approaches for wound repair through protection from pathogen invasion/contamination, maintaining moisture, absorbing exudates, modulating inflammation, and facilitating the healing process. A wide range of materials are used to fabricate wound-healing/dressing biomaterials. Active wound-healing/dressings are next-generation alternatives for passive biomaterials, which provide a physical barrier and induce different biological activities, such as antibacterial, antioxidant, and proliferative effects. Cellulose-based biomaterials are particularly promising due to their tunable physical, chemical, mechanical, and biological properties, accessibility, low cost, and biocompatibility. A thorough description and analysis of wound-healing/dressing structures fabricated from cellulose-based biomaterials is discussed in this review. We emphasize and highlight the fabrication methods, applied bioactive molecules, and discuss the obtained results from in vitro and in vivo models of cellulose-based wound-healing biomaterials. This review paper revealed that cellulose-based biomaterials have promising potential as the wound-dressing/healing materials and can be integrated with various bioactive agents. Overall, cellulose-based biomaterials are shown to be effective and sophisticated structures for delivery applications, safe and multi-customizable dressings, or grafts for wound-healing applications.

Fabrication and evaluation of hesperidin loaded polyacrylonitrile/polyethylene oxide nanofibers for wound dressing application

In this study, hesperidin (HPN) loaded polyacrylonitrile (PAN)/polyethylene oxide (PEO) electrospun nanofibers were prepared for use as wound dressing. Accordingly, HPN loaded hybrid nanofibers were generated via electrospinning. A full factorial design was then applied to evaluate the influence of formulation variables including PEO amount, HPN amount and total polymer amount on the nanofiber features. Fabricated membranes were evaluated in terms of morphology, diameter, entrapment efficiency (EE) %, drug loading (DL) %, release efficiency (RE) %, swelling % and mechanical properties. Analysis of the obtained data showed that the amount of PEO was the most effective factor impacting the swelling and release percentage; by raising the amount of PEO from 20% to 40%, the swelling % and release rate were considerably increased. The optimized nanofibers were found to be non-beaded, smooth and cylindrical with fiber diameter of 126.14 ± 23.96 nm, EE% of 38.58 ± 6.06, DL% of 5.36 ± 0.83, swelling % of 859.90 ± 33.49, RE % of 78.49 ± 0.21, UTS of 0.79 ± 0.13 MPa and Young's moduli of 20.91 ± 2.13 MPa. The physical state of HPN in optimized hybrid nanofibers was examined and the related XRD analysis revealed that HPN was either molecularly dispersed, or it existed in an amorphous state in the nanofibers. The in vivo studies also demonstrated that the wound healing rate in the case of HPN loaded nanofibers was higher when compared with other groups. Moreover, according to H&E and MT stain results, HPN loaded nanofibers did promote the regeneration of skin more effectively, as compared with HPN -free nanofibers. Overall, HPN loaded nanofibers mats prepared in this study have the potential to serve as wound dressings.

Production of wheat germ oil containing multilayer hydrogel dressing

A composite wound dressing has been developed by combining different layers consisting of polymers and textiles. Wheat germ oil (WGO) loaded hydrogels have successfully formed on textile nonwovens by cross-linking sodium alginate (SA) with poly(ethylene glycol) diglycidyl ether (PEGDGE). Following freeze-drying, textile-hydrogel composites have been examined according to their physical properties, pH, fluid handling capacity, water vapour permeability, morphology, chemical structure, and cytotoxicity. Hydrogels containing WGO swelled less than pristine hydrogels. Samples with 1% WGO and no WGO showed swelling of 5.9 and 10.5 g/g after 8 h. WGO inclusion resulted in reduced, but more stable fluid handling properties, with more uniform pore distribution (100-200 μm). Moreover, the proliferation of NIH/3T3 cells significantly improved with 1% WGO contained hydrogels. Also, commercial self-adhesive dressings that secure the hydrogels to the wound area were investigated regarding transfer properties. The proposed product demonstrated 8.05 cm³/cm²/s and 541.37 g/m²/day air and water vapour permeability.

Moisturizing effect of skin patches with hydrophobic and hydrophilic electrospun fibers for atopic dermatitis

Atopic dermatitis (eczema), one of the most common disease and also most difficult to treat, is seeking for novel development not only in medicine but also in bioengineering. Moisturization is the key in eczema treatment as dry skin triggers inflammation that damages the skin barrier. Thus, here we combine electrospun hydrophobic polystyrene (PS) and hydrophilic nylon 6 (PA6) with oils to create patches helping to moisturize atopic skin. The fibrous membranes manufactured using electrospinning: PS, PA6, composite PS - PA6 and sandwich system combining them were characterized by water vapor transmission rates (WVTR) and fluid uptake ability (FUA). To create the most effective moisturizing patches we use borage, black cumin seed and evening primrose oil and tested their spreading. We show a great potential of our designed patches, the oil release tests on a skin and their moisturizing effect were verified. Our results distinctly reveal that both fiber sizes and hydrophilicity/hydrophobicity of polymer influence oil spreading, release from membranes and WVTR measurements. Importantly, the direct skin test indicates the evident increase of hydration for both dry and normal skin after using the patches. The electrospun patches based on the hydrophobic and hydrophilic polymers have outstanding properties to be used as oil carriers for atopic dermatitis treatment.

Surface-Modified Nanocellulose for Application in Biomedical Engineering and Nanomedicine: A Review

Presently, a plenty of concerns related to the environment are due to the overuse of petroleum-based chemicals and products; the synthesis of functional materials, starting from the natural sources, is the current trend in research. The interest for nanocellulose has recently increased in a huge range of fields, from the material science to the biomedical engineering. Nanocellulose gained this leading role because of several reasons: its natural abundance on this planet, the excellent mechanical and optical features, the good biocompatibility and the attractive capability of undergoing surface chemical modifications. Nanocellulose surface tuning techniques are adopted by the high reactivity of the hydroxyl groups available; the chemical modifications are mainly performed to introduce either charged or hydrophobic moieties that include amination, esterification, oxidation, silylation, carboxymethylation, epoxidation, sulfonation, thiol- and azido-functional capability. Despite the several already published papers regarding nanocellulose, the aim of this review involves discussing the surface chemical functional capability of nanocellulose and the subsequent applications in the main areas of nanocellulose research, such as drug delivery, biosensing/bioimaging, tissue regeneration and bioprinting, according to these modifications. The final goal of this review is to provide a novel and unusual overview on this topic that is continuously under expansion for its intrinsic sophisticated properties.

Clinical Translational Potential in Skin Wound Regeneration for Adipose-Derived, Blood-Derived, and Cellulose Materials: Cells, Exosomes, and Hydrogels

Acute and chronic skin wounds due to burns, pressure injuries, and trauma represent a substantial challenge to healthcare delivery with particular impacts on geriatric, paraplegic, and quadriplegic demographics worldwide. Nevertheless, the current standard of care relies extensively on preventive measures to mitigate pressure injury, surgical debridement, skin flap procedures, and negative pressure wound vacuum measures. This article highlights the potential of adipose-, blood-, and cellulose-derived products (cells, decellularized matrices and scaffolds, and exosome and secretome factors) as a means to address this unmet medical need. The current status of this research area is evaluated and discussed in the context of promising avenues for future discovery.

Bio-Based Electrospun Fibers for Wound Healing

Being designated to protect other tissues, skin is the first and largest human body organ to be injured and for this reason, it is accredited with a high capacity for self-repairing. However, in the case of profound lesions or large surface loss, the natural wound healing process may be ineffective or insufficient, leading to detrimental and painful conditions that require repair adjuvants and tissue substitutes. In addition to the conventional wound care options, biodegradable polymers, both synthetic and biologic origin, are gaining increased importance for their high biocompatibility, biodegradation, and bioactive properties, such as antimicrobial, immunomodulatory, cell proliferative, and angiogenic. To create a microenvironment suitable for the healing process, a key property is the ability of a polymer to be spun into submicrometric fibers (e.g., via electrospinning), since they mimic the fibrous extracellular matrix and can support neo- tissue growth. A number of biodegradable polymers used in the biomedical sector comply with the definition of bio-based polymers (known also as biopolymers), which are recently being used in other industrial sectors for reducing the material and energy impact on the environment, as they are derived from renewable biological resources. In this review, after a description of the fundamental concepts of wound healing, with emphasis on advanced wound dressings, the recent developments of bio-based natural and synthetic electrospun structures for efficient wound healing applications are highlighted and discussed. This review aims to improve awareness on the use of bio-based polymers in medical devices.

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

Recently, the electrospun nanofiber mats with appropriate properties for applications in the biomedical area has been more considered. In this regard, we successfully fabricated a novel antibacterial nanofiber mat (ethyl cellulose/poly lactic acid/collagen) (EC/PLA/collagen) incorporated with silver sulfadiazine (AgSD) and then analyzed with the required tests. AgSD was loaded in the developed mats with different contents (0.25%, 0.5% and 0.75%) and then electrospun to prepare nanofiber mats. To check the chemical structure of the developed mat, Fourier transform infrared spectroscopy (FTIR) was assessed. Surface morphological studies were performed by Scanning Electron Microscopy (SEM), which displayed uniform nanofiber mats without any bead formation. When the hydrophilicity was enhanced by decreasing the blending ratios of EC/PLA, the thermal stability of the nanofibers was reduced. The water contact angle (WCA) of NFs enhanced by decreasing the blending ratios of EC/PLA. The antibacterial properties showed the inhibition activity against Bacillus (9.71 ± 1.15 mm) and E. coli (12.46 ± 1.31 mm) bacteria. Besides, nanofibers have improved cell proliferation and adhesion with any cytotoxic effect on NIH 3T3 fibroblast cells. According these results, it seems that the developed mats would be effective scaffold for application in wound dressings.

Cellulose-based Biosensor for Bio-molecules Detection in Medical Diagnosis: A Mini-Review

Background::

Biosensors are widely applied for the detection of bio-molecules in blood glucose , cholesterol, and gene. Cellulose as the most dominating natural polymer has attracted more and more interest, especially in the field of medicine such as advanced medical diagnosis. Cellulose could endow biosensors with improved biocompatibility, biodegradability and nontoxicity, which could help in medical diagnosis. This mini-review summarizes the current development of cellulose-based biosensors as well as their applications in medical diagnosis in recent years.

Methods:

After reviewing recent years’ publications we can say that, there are several kinds of cellulose used in biosensors including different cellulose derivatives, bacterial cellulose and nanocellulose. Different types of cellulose-based biosensors, such as membrane, nano-cellulose and others were briefly described in addition to the detection principle. Cellulose-based biosensors were summarized as in the previous papers. The description of various methods used for preparing cellulose-based biosensors was also provided.

Results:

Cellulose and its derivatives with their unique chemical structure proved to be versatile materials providing a good platform for achieving immobilizing bioactive molecules in biosensors. These cellulose-based biosensors possess various desirable properties such as accuracy, sensitivity, convenience, low cost and fast response. Among them, cellulose paper-based biosensors have the advantages of low cost and easy operation. Nano-cellulose has unique properties such as a large aspect ratio, good dispersing ability and high absorption capacity.

Conclusion:

Cellulose displays a promising application in biosensors which could be used to detect different bio-molecules such as glucose, lactate, urea, gene, cell, amino acid, cholesterol, protein and hydroquinone. In future, the attention will be focused on designing miniaturized, multifunctional, intelligent and integrated biosensors. Creation of low cost and environmentally friendly biosensors is also very important.

Electrospun cellulose acetate/gelatin nanofibrous wound dressing containing berberine for diabetic foot ulcer healing: in vitro and in vivo studies

Functional wound dressing with tailored physicochemical and biological properties is vital for diabetic foot ulcer (DFU) treatment. Our main objective in the current study was to fabricate Cellulose Acetate/Gelatin (CA/Gel) electrospun mat loaded with berberine (Beri) as the DFU-specific wound dressing. The wound healing efficacy of the fabricated dressings was evaluated in streptozotocin-induced diabetic rats. The results demonstrated an average nanofiber diameter of 502 ± 150 nm, and the tensile strength, contact angle, porosity, water vapor permeability and water uptake ratio of CA/Gel nanofibers were around 2.83 ± 0.08 MPa, 58.07 ± 2.35°, 78.17 ± 1.04%, 11.23 ± 1.05 mg/cm2/hr, and 12.78 ± 0.32%, respectively, while these values for CA/Gel/Beri nanofibers were 2.69 ± 0.05 MPa, 56.93 ± 1°, 76.17 ± 0.76%, 10.17 ± 0.21 mg/cm2/hr, and 14.37 ± 0.42%, respectively. The antibacterial evaluations demonstrated that the dressings exhibited potent antibacterial activity. The collagen density of 88.8 ± 6.7% and the angiogenesis score of 19.8 ± 3.8 obtained in the animal studies indicate a proper wound healing. These findings implied that the incorporation of berberine did not compromise the physical properties of dressing, while improving the biological activities. In conclusion, our results indicated that the prepared mat is a proper wound dressing for DFU management and treatment.