Electrospun antibacterial polyurethane-cellulose acetate-zein composite mats for wound dressing

Electrospun Cerium Oxide Nanoparticle/Aloe Vera Extract-Loaded Nanofibrous Poly(Ethylene Oxide)/Polyurethane Mats As Diabetic Wound Dressings

Currently the prevalence of diabetic wounds brings a huge encumbrance onto patients, causing high disability and mortality rates and a major medical challenge for society. Therefore, in this study, we are targeting to fabricate aloe vera extract infused biocompatible nanofibrous patches to facilitate the process of diabetic wound healing. Additionally, clindamycin has been adsorbed onto the surface of in-house synthesized ceria nanoparticles and again used separately to design a nanofibrous web, as nanoceria can act as a good drug delivery vehicle and exhibit both antimicrobial and antidiabetic properties. Various physicochemical characteristics such as morphology, porosity, and chemical composition of the produced nanofibrous webs were investigated. Bacterial growth inhibition and antibiofilm studies of the nanofibrous materials confirm its antibacterial and antibiofilm efficacy against Gram-positive and Gram-negative bacteria. An in vitro drug release study confirmed that the nanofibrous mat show a sustained drug release pattern (90% of drug in 96 h). The nanofibrous web containing drug loaded nanoceria not only showed superior in vitro performance but also promoted greater wound contraction (95 ± 2%) in diabetes-induced mice in just 7 days. Consequently, it efficaciously lowers the serum glucose level, inflammatory cytokines, oxidative stress, and hepatotoxicity markers as endorsed by various ex vivo tests. Conclusively, this in-house-fabricated biocompatible nanofibrous patch can act as a potential medicated suppository that can be used for treating diabetic wounds in the proximate future.

Development and characterization of active packaging system based on zein nanofibers mat incorporated with geraniol-loaded nanoliposomes

In recent years, development of biopolymeric nanofibers as an active biodegradable packaging system has attracted specific attention. The objective of this research was to develop zein-based electrospun nanofibers (NFs) incorporated with geraniol-loaded nanoliposomes (G-loaded NLPs). Geraniol was encapsulated into NLPs with an efficiency of 79.23%. The particle size and zeta potential of G-loaded NLPs were 121.50 nm and -38.30 mV, respectively. The successful loading of geraniol in the NLPs was approved by Fourier transform infrared (FT-IR) spectroscopy. The liposomal vesicles showed spherical shapes. G-loaded NLPs were added in the zein-based electrospun NFs at three different concentrations (0.25, 0.5, and 1%w/v). All NFs samples exhibited fibrillar structure. The increase of NLPs concentration enhanced the thermal stability of the NFs. However, the crystalline structure of zein NFs did not change by the addition of G-loaded NLPs. The highest surface hydrophobicity was related to the NFs containing 1% G-loaded NLPs. The mechanical parameters of NFs depend on the concentration of NLPs. The NFs incorporated with G-loaded NLPs showed inhibition activity against four foodborne pathogenic bacteria (Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, and Salmonella typhimurium) with an inhibition zone of 4.5-22 mm. Moreover, the α-diphenyl-β-picrylhydrazyl (DPPH) scavenging activity of NFs samples was located at the range of 20%-48%. These findings represent the Efficiency of the G-loaded NLPs for use as bioactive compound in the zein-based NFs as an active packaging material.

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

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

Preparation and Investigation of Cellulose Acetate/Gelatin Janus Nanofiber Wound Dressings Loaded with Zinc Oxide or Curcumin for Enhanced Antimicrobial Activity

The skin, as the largest organ, serves as a protective barrier against external stimuli. However, when the skin is injured, wound healing becomes a complex process influenced by physiological conditions, bacterial infections, and inflammation. To improve the process of wound healing, a variety of wound dressings with antibacterial qualities have been created. Electrospun nanofibers have gained significant attention in wound dressing research due to their large specific surface area and unique structure. One interesting method for creating Janus-structured nanofibers is side-by-side electrospinning. This work used side-by-side electrospinning to make cellulose acetate/gelatin Janus nanofibers. Curcumin and zinc oxide nanoparticles were added to these nanofibers. We studied Janus nanofibers' physicochemical characteristics and abilities to regulate small-molecule medication release. Janus nanofibers coated with zinc oxide nanoparticles and curcumin were also tested for antibacterial activity. The Janus nanofibers with specified physicochemical characteristics were successfully fabricated. Nanofibers released small-molecule medicines in a controlled manner. Additionally, the Janus nanofibers loaded with curcumin exhibited excellent antibacterial capabilities. This research contributes to the development of advanced wound dressings for promoting wound healing and combating bacterial infections.

Poly(vinyl alcohol) /Alginate nanofibrous mats containing Malva Sylvestris extract: Synthesis, characterization, in vitro and in vivo assessments for burn wound applications

An important part of wound healing is providing effective wound care, coupled with preventing wound infection, which slows or disrupts healing. There are currently many herbal plants that have historical supernatural properties that show remarkable wound healing abilities. These herbal extracts have shown promising results when applied to electrospun nanofibrous mats platforms for wound healing. Accordingly, Malva Sylvestris extract (MS) was electrospun into polyvinyl alcohol/alginate nanofibrous mats (PVA/ALG). Field Emission Scanning Electron Microscopy (FESEM) demonstrated that the fiber diameter ranged from approximately 100-200 nm in nanofibrous mats, with a uniform appearance without beads. MS extract was detected in nanofibrous mats by Fourier Transform Infrared Spectroscopy (FTIR). A major benefit of incorporating MS extract into PVA/ALG nanofibrous mats is that their alterations have resulted in enhanced mechanical characteristics. The nanofibrous mats containing MS extracts showed significantly increased antibacterial efficacy against Gram-positive and Gram-negative bacteria. Based on the findings from in vivo experiments, the PVA/ALG/MS1 (M2) dressing demonstrated a wound closure rate of 93-94 % within 21 days of treatment in rats, indicating its significant potential for use as a wound dressing agent in the treatment of burn injuries. The combination of PVA, ALG, and MS1 in this nanofibrous mats exhibited beneficial properties, including biocompatibility, suitable mechanical strength, and the ability to promote cellular proliferation and angiogenesis, further validating its effectiveness as a wound healing dressing.

Synthesis of Cross-Linked and Sterilized Water-Soluble Electrospun Nanofiber Biomatrix of Streptomycin-Imbedded PVA/CHN/β-CD for Wound Healing

The diagnosis and prognosis of chronic wounds are demanding and require objective assessment. Because of their potential medicinal applications, the syntheses of biopolymeric chitosan (CHN) structure and PVA-based mixed electrospun nanofibers with biomimetic features were thoroughly investigated. This study created different formulas, including a guest molecule and capping agent, using supporting PVA as a vehicle. CHN was used as a biomodifier, and beta-cyclodextrin (ß-CD) as a smoother and more efficiently entraps streptomycin (STP) compared with the silver sheet wound dressing. The relevant analyses showed that the size distribution increased with the incorporation of PVA, CHN, and ß-CD to 120.3, 161.9, and 192.02 nm. The webs boosted particle size and released content stability to 96.4% without compromising the nanofiber structure. Examining the synergistic effects of the PVA/CHN/STP/ß-CD nanoformulation against pathogenic strains of S. aureus, P. aeruginosa, and Aspergillus niger, clean zones were 47 ± 3.4, 45 ± 3.0, and 49 ± 3.7 mm were produced. PVA/CHN/STP/ß-CD formula exhibited a 98.9 ± 0.6% cell viability and wound closure of 100% at 72 h. The results reveal that the PVA/CHN/STP/ß-CD formula is promising for medical applications, especially in wound healing, compared with the silver sheet.

Revolution of nanotechnology in food packaging: Harnessing electrospun zein nanofibers for improved preservation - A review

Zein, a protein-based biopolymer derived from corn, has garnered attention as a promising and eco-friendly choice for packaging food due to its favorable physical attributes. The introduction of electrospinning technology has significantly advanced the production of zein-based nanomaterials. This cutting-edge technique enables the creation of nanofibers with customizable structures, offering high surface area and adjustable mechanical and thermal attributes. Moreover, the electrospinning process allows for integrating various additives, such as antioxidants, antimicrobial agents, and flavoring compounds, into the zein nanofibers, enhancing their functionalities for food preservation. In this comprehensive review, the various electrospinning techniques employed for crafting zein-based nanofibers, and we delve into their enhanced properties. Furthermore, the review illuminates the potential applications of zein nanofibers in active and intelligent packaging materials by incorporating diverse constituents. Altogether, this review highlights the considerable prospects of zein-based nanocomposites in the realm of food packaging, offering sustainable and innovative solutions for food industry.

A novel designed nanofibrous mat based on hydroxypropyl methyl cellulose incorporating mango peel extract for potential use in wound care system

Skin tissue is damaged by factors such as burns, physical injuries and diseases namely diabetes. Infection and non-healing of burn wounds and lack of angiogenesis in diabetic wounds lead to extensive injuries and death. Therefore, the design of wound dressings with antibacterial and restorative capabilities is very important. In this study, nanofibers (NFs) including polyurethane (PU) and hydroxypropyl methyl cellulose (HPMC) were prepared with different ratios and Mango peel extract (MPE) loaded into NFs by electrospinning method. The morphology, chemical structure, porosity, degradation, water vapor permeability, mechanical properties, wettability, antioxidant activity and some cell studies and evaluation of their antibacterial properties were investigated. The optimal mat (PU90/HPMC10) had a defect-free morphology with homogeneous NFs. Furthermore, it showed improved biodegradability, water vapor permeability and porosity compared to other Mats. All NFs were non-toxic with hydrophilic behavior in the cellular environment and had acceptable hemocompatibility. The PU90/HPMC10/20 % optimal scaffold had significantly higher cell viability and proliferation than other samples and also had a higher antibacterial ability against pathogenic bacteria S. aureus (17 mm) and E. coli (11 mm). All these findings confirm that the produced NF mats, especially those loaded with MPE, have a high potential to be used as an effective wound dressing.

Improving the Performance of Poly(caprolactone)-Cellulose Acetate-Tannic Acid Tubular Scaffolds by Mussel-Inspired Coating

Small-diameter artificial blood vessels are increasingly being used in clinical practice. However, these vessels are prone to thrombus, and it is necessary to improve blood compatibility. Surface coating is one of the commonly used methods in this regard. Inspired by the biomimicry of mussels, the use of deposition technology to obtain coating coverage on the surface of fibers has significantly piqued the interest of researchers recently. In this study, tubular scaffolds consisting of a composite of poly(caprolactone), cellulose acetate, and tannic acid (TA) were electrospun, and then the scaffolds were treated with different Fe(III) solutions (iron(III) chloride hexahydrate (FeCl3'6H2O)) to obtain four tubular scaffolds: F0, F5, F15, and F45. According to scanning electron microscopy (SEM) and field emission-SEM results, TA/Fe(III) complex is coated on the fiber of the scaffold after post-treatment; the fiber surface morphology changes with different Fe(III) concentrations. This provides designability to the performance of tubular scaffolds. The tensile strength of the F5 tubular scaffold (3.33 MPa) is higher than that of F45 (3.14 MPa), while the strain (83.9%) of the F45 tubular stent was 2.26 times that of the F5 (37.2%). In addition, cytotoxicity and antithrombotic performance were evaluated. The test results show that surface TA/Fe(III) coating treatment can affect the cytotoxicity and anticoagulation performance of the scaffold surface. The biomimetic TA/Fe(III) coating of mussels used in this study improves the performance of artificial blood vessels.

Synthetic Pressure Sensitive Adhesives for Biomedical Applications

Pressure sensitive adhesives are components of everyday products found in homes, offices, industries, and hospitals. Serving the general purpose of fissure repair and object fixation, pressure sensitive adhesives indiscriminately bind surfaces, as long as contact pressure is administered at application. With that being said, the chemical and material properties of the adhesive formulation define the strength of a pressure sensitive adhesive to a particular surface. Given our increased understanding of the viscoelastic material requirements as well as the intermolecular interactions at the binding interface required for functional adhesives, pressure sensitive adhesives are now being explored for greater use. New polymer formulations impart functionality and degradability for both internal and external applications. This review highlights the structure-property relationships between polymer architecture and pressure sensitive adhesion, specifically for medicine. We discuss the rational, molecular-level design of synthetic polymers for durable, removable, and biocompatible adhesion to wet surfaces like tissue. Finally, we examine prevalent challenges in biomedical wound closure and the new, innovative strategies being employed to address them. We conclude by summarizing the progress of current research, identifying additional clinical opportunities, and discussing future prospects.

Synthesis and characterization of natural fibers reinforced alginate hydrogel fibers loaded with diclofenac sodium for wound dressings

Hydrogels which become increasingly important in the biomedical field are composed of a three-dimensional hydrophilic network. Pure hydrogels are usually weak and brittle; therefore, reinforcements are assimilated into the hydrogel structure to improve the mechanical strength of the hydrogels. However, even if mechanical properties are enhanced, drapability remains an issue. In that regard, natural fiber-reinforced composite hydrogel fibers for wound dressing application are investigated in this study. Kapok and hemp fibers were used as reinforcement to improve the strength of hydrogel fibers. The properties of the prepared composite hydrogel fibers were studied with Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and differential scanning calorimeter (DSC). The effect of alginate concentration and fiber weight percent on the mechanical characteristics and water absorbency was studied. Diclofenac sodium drug was loaded in the hydrogel fibers and investigated the drug release as well as antibacterial characteristics. Both fibers' reinforcement enhanced the strength of the alginate hydrogel fiber, but hemp reinforcement showed better mechanical properties. Kapok reinforcement resulted in a maximum tensile strength of 174 cN (1.24 % elongation) and 432 % exudate absorbency, while hemp reinforcement resulted in 185 cN (1.48 % elongation) and 435 % exudate absorbency. Statistical analysis revealed significant effects of sodium alginate concentration on tensile strength (p-value 0.042) and exudate absorbency (p-value 0.020) and of reinforcement (wt%) on exudate absorbency (p-value 0.043). Therefore, these composite hydrogel fibers with improved mechanical properties are capable of drug release and exhibit antibacterial effectiveness, making them a promising option for use as wound dressings.

Preparation, optimization, and in vitro-in vivo evaluation of sorafenib-loaded polycaprolactone and cellulose acetate nanofibers for the treatment of cutaneous leishmaniasis

The most common form of leishmaniasis is cutaneous leishmaniasis (CL). The major difficulties in the treatment of leishmaniasis include emergence of resistance, toxicity, long-term treatment, and the high cost of the current drugs. Although the therapeutic effect of sorafenib (SF) has been demonstrated in both in vitro and in vivo models of Leishmania infection, the therapeutic applications are limited due to severe drug-related toxicity; this is, in turn, due to non-specific distribution in the body. Thus, topical delivery has the advantage of the site directed delivery of SF. This research study evaluated SF-loaded hybrid nanofibers (NFs) which were composed of polycaprolactone (PCL) and cellulose acetate (CA) for the CL topical treatment. Accordingly, SF-loaded hybrid NFs were prepared using the electrospinning method. Formulation variables including total polymer concentration, drug/polymer ratio, and CA concentration were optimized using a full factorial design. The prepared SF-loaded NFs were then characterized for morphology, diameter, encapsulation efficiency (EE)%, drug loading (DL) %, and percentage of release efficiency during a 24-h period (RE_24h%); the mechanical characteristics were also considered. The physical state of the drug in the optimized NF was evaluated by the X-ray diffraction analysis. Finally, its in vivo efficacy was determined in L. major-infected mice. The optimized formulation had a smooth, cylindrical, non-beaded shape fiber with a diameter of 281.44 nm, EE of 97.96%, DL of 7.48%, RE of 51.05%, ultimate tensile strength of 1.08 MPa, and Young's moduli of 74.96 MPa. The XRD analysis also demonstrated the amorphous state of SF in NF. Further, the in vivo results displayed the higher anti-leishmanial activity of the SF-loaded hybrid NF by efficiently healing lesion and successfully reducing the parasite burden. This, thus, indicated the potential of the clinical capability of the SF-loaded hybrid NF for the effective treatment of CL.

Effect of surface structure on the antithrombogenicity performance of poly(-caprolactone)-cellulose acetate small-diameter tubular scaffolds

Small-diameter artificial blood vessels have always faced the problem of thrombosis. In this research, three types of poly(-caprolactone)-cellulose acetate (PCL-CA) composite nanofiber membranes were prepared by various collectors to make into a tubular scaffold with a 4.5-mm diameter. The collector consisted of two sizes of stainless steel wire mesh large-mesh (LM) and small-mesh (SM), respectively. There is also a random flat (RF) that acts as the third type collector. The nanofiber membrane's surface structure mimicked the collectors' surface morphology, they named LM, SM and RF scaffolds. The water contact angles of RF and LM scaffolds are 126.5° and 105.5°, and the distinct square-groove construction greatly improves the contact angle of LM. The tubular scaffolds' radial mechanical property test demonstrated that the large-mesh (LM) tubular scaffold enhanced the strain and tensile strength; the tensile strength and strain are 30 % and 148 % higher than that of the random-flat (RF) tubular scaffold, respectively. The suture retention strength value of the LM tubular scaffold was 103 % higher than that of the RF tubular scaffold. The cytotoxicity and antithrombogenicity performance were also evaluated, the LM tubular scaffold has 88 % cell viability, and the 5-min blood coagulation index (BCI) value was 89 %, which is much higher than other tubular scaffolds. The findings indicate that changing the tubular scaffold's surface morphology cannot only enhance the mechanical and hydrophilic properties but also increase cell survival and antithrombogenicity performance. Thus, the development of a small-diameter artificial blood vessel will be a big step toward solving the problem on thrombosis. Furthermore, artificial blood vessel is expected to be a candidate material for biomedical applications.

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.

Recent advances in electrospun protein fibers/nanofibers for the food and biomedical applications

Electrospinning (ES) is one of the most investigated processes for the convenient, adaptive, and scalable manufacturing of nano/micro/macro-fibers. With this technique, virgin and composite fibers may be made in different designs using a wide range of polymers (both natural and synthetic). Electrospun protein fibers (EPF) shave desirable capabilities such as biocompatibility, low toxicity, degradability, and solvolysis. However, issues with the proteins' processibility have limited their widespread utilization. This paper gives an overview of the features of protein-based biomaterials, which are already being employed and has the potential to be exploited for ES. State-of-the-art examples showcasing the usefulness of EPFs in the food and biomedical industries, including tissue engineering, wound dressings, and drug delivery, provided in the applications. The EPFs' future perspective and the challenge they pose are presented at the end. It is believed that protein and biopolymeric nanofibers will soon be manufactured on an industrial scale owing to the limitations of employing synthetic materials, as well as enormous potential of nanofibers in other fields, such as active food packaging, regenerative medicine, drug delivery, cosmetic, and filtration.

High performance flexible and antibacterial strain sensor based on silver‑carbon nanotubes coated cellulose/polyurethane nanofibrous membrane: Cellulose as reinforcing polymer blend and polydopamine as compatibilizer

In this study, ethyl cellulose was used as the second-phase polymer blended with polyurethane to make nanofibrous membrane as antibacterial strain sensor. The results indicated that ethyl cellulose could regulate the morphology of polyurethane through strong hydrogen bonding, which observably enhanced the nanofiber uniformity of polyurethane. Furthermore, rigid cellulose also remarkably improved the mechanical strength and thermal stability of the nanofibrous membrane. After being coated with silver nanoparticles and carbon nanotubes assisted by polydopamine (PDA), the membrane with outstanding bacteria inhibition performance exhibited outstanding sensitivity toward external mechanical stretching, as well as real-time motion of human body parts. The conductive composite membrane possessed sensitive and regular resistance feedback to 100 cycles of varied human motions. The cellulose in the nanofiber structure ensured the shape recovery and longtime use stability of the membrane. This study proposed a novel thinking for the construction of high performance strain sensor by rational introduction of rigid polysaccharide into the polymer matrix.

Electrospun hybrid nanofibers: Fabrication, characterization, and biomedical applications

Nanotechnology is one of the most promising technologies available today, holding tremendous potential for biomedical and healthcare applications. In this field, there is an increasing interest in the use of polymeric micro/nanofibers for the construction of biomedical structures. Due to its potential applications in various fields like pharmaceutics and biomedicine, the electrospinning process has gained considerable attention for producing nano-sized fibers. Electrospun nanofiber membranes have been used in drug delivery, controlled drug release, regenerative medicine, tissue engineering, biosensing, stent coating, implants, cosmetics, facial masks, and theranostics. Various natural and synthetic polymers have been successfully electrospun into ultrafine fibers. Although biopolymers demonstrate exciting properties such as good biocompatibility, non-toxicity, and biodegradability, they possess poor mechanical properties. Hybrid nanofibers from bio and synthetic nanofibers combine the characteristics of biopolymers with those of synthetic polymers, such as high mechanical strength and stability. In addition, a variety of functional agents, such as nanoparticles and biomolecules, can be incorporated into nanofibers to create multifunctional hybrid nanofibers. Due to the remarkable properties of hybrid nanofibers, the latest research on the unique properties of hybrid nanofibers is highlighted in this study. Moreover, various established hybrid nanofiber fabrication techniques, especially the electrospinning-based methods, as well as emerging strategies for the characterization of hybrid nanofibers, are summarized. Finally, the development and application of electrospun hybrid nanofibers in biomedical applications are discussed.

Overexpression of VEGF in dermal fibroblast cells accelerates the angiogenesis and wound healing function: in vitro and in vivo studies

Fibroblasts are the main cells of connective tissue and have pivotal roles in the proliferative and maturation phases of wound healing. These cells can secrete various cytokines, growth factors, and collagen. Vascular endothelial growth factor (VEGF) is a unique factor in the migration process of fibroblast cells through induces wound healing cascade components such as angiogenesis, collagen deposition, and epithelialization. This study aimed to create VEGF₁₆₅ overexpressing fibroblast cells to evaluate angiogenesis function in wound healing. In vitro, a novel recombinant expression vector, pcDNA3.1(-)-VEGF, was produced and transfected into the fibroblast cells. Following selecting fibroblast cells with hygromycin, recombinant cells were investigated in terms of VEGF expression by quantifying and qualifying methods. Mechanical, physical, and survival properties of polyurethane-cellulose acetate (PU-CA) scaffold were investigated. Finally, in vivo, the angiogenic potential was evaluated in four groups containing control, PU-CA, PU-CA with fibroblast cells, and VEGF-expressing cells on days 0, 2, 5, 12 and 15. Wound biopsies were harvested and the healing process was histopathologically evaluated on different days. qRT-PCR showed VEGF overexpression (sevenfold) in genetically-manipulated cells compared to fibroblast cells. Recombinant VEGF expression was also confirmed by western blotting. Manipulated fibroblast cells represented more angiogenesis than other groups on the second day after surgery, which was also confirmed by the antiCD31 antibody. The percentage of wound closure area on day 5 in genetically-manipulated Hu02 and Hu02 groups showed a significant reduction of wound area compared to other groups. These findings indicate that overexpression of VEGF₁₆₅ in fibroblast cells results in enhanced angiogenesis and formation of granulated tissue in the early stage of the healing process, which can show its therapeutic potential in patients with impaired wound healing and also provide functional support for gene therapy.

Hemostatic Alginate/Nano-Hydroxyapatite Composite Aerogel Loaded with Tranexamic Acid for the Potential Protection against Alveolar Osteitis

Wound control in patients on anticoagulants is challenging and often leads to poor hemostasis. They have a higher tendency to develop alveolar osteitis after tooth extraction. The application of a hemostatic dressing that has a high absorbing capacity and is loaded with an antifibrinolytic drug could help in controlling the bleeding. Alginate/nano-hydroxyapatite (SA/Nano-HA) composite aerogels loaded with tranexamic acid (TXA) were prepared. Nano-HA served as a reinforcing material for the alginate matrix and a source of calcium ions that helps in blood clotting. It influenced the porosity and the water uptake capacity. TXA release from SA/Nano-HA aerogels showed a biphasic profile for up to 4 h. Blood coagulation studies were performed on human whole blood. The TXA-loaded aerogel significantly reduced the clotting time by 69% compared to the control (p < 0.0001). Recalcification time was significantly reduced by 80% (p < 0.0001). Scanning electron microscopy analysis revealed the porous nature of the aerogels and the ability of the optimum aerogel to activate and adhere platelets to its porous surface. The cell migration assay showed that there was a delay in wound healing caused by the TXA aerogel compared to the control sample after treating human fibroblasts. Results suggest that the developed aerogel is a promising dressing that will help in hemostasis after tooth extraction.

Progress of Polysaccharide-Contained Polyurethanes for Biomedical Applications

Polyurethane (PU) has been widely examined and used for biomedical applications, such as catheters, blood oxygenators, stents, cardiac valves, drug delivery carriers, dialysis devices, wound dressings, adhesives, pacemaker, tissue engineering, and coatings for breast implants due to its mechanical flexibility, high tear strength, biocompatibility, and tailorable foams although bio-acceptability, biodegradability and controlled drug delivery to achieve the desired properties should be considered. Especially, during the last decade, the development of bio-based PUs has raised public awareness because of the concern with global plastic waste for creating more environmentally friended materials. Therefore, it is desirable to discuss polysaccharide (PS)-contained PU for the wound dressing and bone tissue engineering among bio-based PUs because PS has several advantages, such as biocompatibility, reproducibility from the natural resources, degradability, ease of incorporation of bioactive agents, ease of availability and cost-effectiveness, and structural feature of chemical modification to meet the desired needs to overcome the disadvantages of PU itself by containing the PS into the PU.

Heat-Stimuli Shape Memory Effect of Poly (ε-Caprolactone)-Cellulose Acetate Composite Tubular Scaffolds

Small-diameter artery disease is the most common clinical occurrence, necessitating the development of small-diameter artificial blood vessels. In this study, seven types of poly(-caprolactone)-cellulose acetate (PCL-CA) composite nanofiber membranes were prepared with different proportions of PCL and CA. The adhesion and growth of Mc3t3-e1 cells were considered to confirm the in vitro cytocompatibility of PCL-CA membranes. A smooth stainless-steel mandrel with a diameter of 4 mm was used to roll up the prepared nanofiber membranes to produce the tubular scaffold with 50 °C hot water. The tubular scaffolds were subjected to axial and circumferential tensile tests. The mechanical performance of the PCL-CA tubular scaffold could be improved by increasing the layers. In addition, the burst pressure (BP) of the tubular scaffolds was increased with the layers, and the BPs of six-layer (2380 ± 36.8 mmHg) and eight-layer (3720 ± 80.5 mmHg) tubular scaffolds were much higher than that of the human saphenous vein (2000 mmHg). The compression shape memory performances of the PCL-CA tubular scaffold with different layers were also investigated to simulate and analyze the contraction and expansion of tubular scaffolds. The experimental results showed that the compression strain of the tubular scaffold in the diameter direction reached 35%, and the ultimate shape recovery rate reached 87%. However, the shape fixity rate and shape recovery rate increased, demonstrating that the optimum number of layers can improve the compression shape memory performance of the tubular scaffold. The results of this study, including comprehensive morphological and mechanical properties and cytocompatibility, indicated the potential applicability of PCL-CA tubular scaffolds as tissue engineering grafts.

Rational design of biodegradable thermoplastic polyurethanes for tissue repair

As a type of elastomeric polymers, non-degradable polyurethanes (PUs) have a long history of being used in clinics, whereas biodegradable PUs have been developed in recent decades, primarily for tissue repair and regeneration. Biodegradable thermoplastic (linear) PUs are soft and elastic polymeric biomaterials with high mechanical strength, which mimics the mechanical properties of soft and elastic tissues. Therefore, biodegradable thermoplastic polyurethanes are promising scaffolding materials for soft and elastic tissue repair and regeneration. Generally, PUs are synthesized by linking three types of changeable blocks: diisocyanates, diols, and chain extenders. Alternating the combination of these three blocks can finely tailor the physio-chemical properties and generate new functional PUs. These PUs have excellent processing flexibilities and can be fabricated into three-dimensional (3D) constructs using conventional and/or advanced technologies, which is a great advantage compared with cross-linked thermoset elastomers. Additionally, they can be combined with biomolecules to incorporate desired bioactivities to broaden their biomedical applications. In this review, we comprehensively summarized the synthesis, structures, and properties of biodegradable thermoplastic PUs, and introduced their multiple applications in tissue repair and regeneration. A whole picture of their design and applications along with discussions and perspectives of future directions would provide theoretical and technical supports to inspire new PU development and novel applications.

Antibody-targeted and streptomycin-chitosan oligosaccharide-modified gold nanoshells for synergistic chemo-photothermal therapy of drug-resistant bacterial infection

Despite the many advanced strategies that are available, rapid gene mutation in multidrug-resistant bacterial infections remains a major challenge. Combining new therapeutic strategies such as chemo-photothermal therapy (PTT) with high antibacterial efficiency against drug-resistant Listeria monocytogenes (LM) is urgently needed. Here, we report synergistic chemo-PTT against drug-resistant LM based on antibody-targeted and streptomycin-chitosan oligosaccharide-modified gold nanoshells (anti-STR-CO-GNSs) as all-in-one nanotheranostic agents for the first time, which was used for accurate antibacterial applications. The anti-STR-CO-GNSs showed excellent photothermal conversion efficiency (31.97%) and were responsive to near-infrared (NIR) and pH dual stimuli-triggered antibiotic release, resulting in outstanding chemo-photothermal effects against LM. In vitro chemo-photothermal effect of anti-STR-CO-GNSs with laser irradiation caused a greater antibacterial effect (1.37%), resulting in more rapid killing of LM and prevention of LM regrowth. Most importantly, the mice receiving the anti-STR-CO-GNSs with laser irradiation specifically at the sites of LM infections healed almost completely, leaving only scars on the surface of the skin and resulting in superior inhibitory effects from combined chemo-PTT. Overall, our findings suggest that chemo-PTT using smart biocompatible anti-STR-CO-GNSs is a favorable potential alternative to combat the increasing threat of drug-resistant LM, which opens a new door for clinical anti-infection therapy in the future.

Electrospun kaolin-loaded chitosan/PEO nanofibers for rapid hemostasis and accelerated wound healing

Development of chitosan-based hemostatic products and their application in wound healing has always been a research hotspot in the field of emergency treatment and biomedicine. In this study, the classic hemostatic chitosan and the most well-known inorganic hemostatic agent-kaolin were tried to combine to form a more excellent dressing. Together with the aid of non-toxic, harmless and good hydrophilic polyethylene oxide, chitosan/polyethylene oxide (PEO)/kaolin nanofiber membranes (CPKs) were prepared by electrospinning technology. Such membranes exhibited adjustable mechanical properties and good biocompatibility. Furthermore, a series of in vitro coagulation experiments proved that CPKs with 10 % ratio of kaolin (CPK10) has excellent hemostatic ability. Especially, in the whole blood coagulation time (WBCT) assay, the hemostatic time of CPK10 (43 ± 1.4 s) was significantly lower than that of chitosan/polyethylene oxide (CPK0) nanofiber membrane (61 ± 2.2 s) and QuikClot® Combat Gauze (55.7 ± 1.2 s). The further rat liver injury test reconfirmed that CPK10 can stop bleeding better and faster compared to other groups. In addition, CPKs could promote back wound healing in rats within 14 days without significant inflammatory response. This safe and effective hemostatic CPKs is expected to be a promising candidate hemostat in pre-hospital medical care.

Co-Loading of Inorganic Nanoparticles and Natural Oil in the Electrospun Janus Nanofibers for a Synergetic Antibacterial Effect

Side-by-side electrospinning is a powerful but challenging technology that can be used to prepare Janus nanofibers for various applications. In this work, cellulose acetate (CA) and polycaprolactone (PCL) were used as polymer carriers for silver nanoparticles (Ag NPs) and lavender oil (LO), respectively, processing these into two-compartment Janus fibers. A bespoke spinneret was used to facilitate the process and prevent the separation of the working fluids. The process of side-by-side electrospinning was recorded with a digital camera, and the morphology and internal structure of the products were characterized by electron microscopy. Clear two-compartment fibers are seen. X-ray diffraction patterns demonstrate silver nanoparticles have been successfully loaded on the CA side, and infrared spectroscopy indicates LO is dispersed on the PCL side. Wetting ability and antibacterial properties of the fibers suggested that PCL-LO//CA-Ag NPs formulation had strong antibacterial activity, performing better than fibers containing only one active component. The PCL-LO//CA-Ag NPs had a 20.08 ± 0.63 mm inhibition zone for E. coli and 19.75 ± 0.96 mm for S. aureus. All the fibers had water contact angels all around 120°, and hence, have suitable hydrophobicity to prevent water ingress into a wound site. Overall, the materials prepared in this work have considerable promise for wound healing applications.

Antibacterial and hemostatic capacities of cellulose nanocrystalline-reinforced poly(vinyl alcohol) electrospun mats doped with Tiger 17 and pexiganan peptides for prospective wound healing applications

Infection is a major issue in chronic wound care. Different dressings have been developed to prevent microbial propagation, but an effective, all-in-one (cytocompatible, antimicrobial and promoter of healing) solution is still to be uncovered. In this research, polyvinyl alcohol (PVA) nanofibrous mats reinforced with cellulose nanocrystal (CNC), at 10 and 20% v/v ratios, were produced by electrospinning, crosslinked with glutaraldehyde vapor and doped with specialized peptides. Crosslinking increased the mats' fiber diameters but maintained their bead-free morphology. Miscibility between polymers was confirmed by Fourier-transform infrared spectroscopy and thermal evaluations. Despite the incorporation of CNC having reduced the mats' mechanical performance, it improved the mats' surface energy and its structural stability over time. Pexiganan with an extra cysteine group was functionalized onto the mats via hydroxyl- polyethylene glycol 2-maleimide, while Tiger 17 was physisorbed to preserve its cyclic conformation. Antimicrobial assessments demonstrated the peptide-doped mat's effectiveness against Staphylococcus aureus and Pseudomonas aeruginosa; pexiganan contributed mostly for such outcome. Tiger 17 showed excellent capacity in accelerating clotting. Cytocompatibility evaluations attested to these mats' safety. C90/10 PVA/CNC mats were deemed the most effective from the tested group and, thus, a potentially effective option for chronic wound treatments.

Tiger 17 and pexiganan as antimicrobial and hemostatic boosters of cellulose acetate-containing poly(vinyl alcohol) electrospun mats for potential wound care purposes

In this research, we propose to engineer a nanostructured mat that can simultaneously kill bacteria and promote an environment conducive to healing for prospective wound care. Polyvinyl alcohol (PVA) and cellulose acetate (CA) were combined at different polymer ratios (100/0, 90/10, 80/20% v/v), electrospun and crosslinked with glutaraldehyde vapor. Crosslinked fibers increased in diameter (from 194 to 278 nm), retaining their uniform structure. Fourier-transform infrared spectroscopy and thermal analyses proved the excellent miscibility between polymers. CA incorporation incremented the fibers swelling capacity and reduced the water vapor and air permeabilities of the mats, preventing the excessive drying of wounds. The antimicrobial peptide cys-pexiganan and the immunoregulatory peptide Tiger 17 were incorporated onto the mats via polyethylene glycol spacer (hydroxyl-PEG2-maleimide) and physisorbed, respectively. Time-kill kinetics evaluations revealed the mats effectiveness against Staphylococcus aureus and Pseudomonas aeruginosa. Tiger 17 played a major role in accelerating clotting of re-calcified plasma. Data reports for the first time the collaborative effect of pexiganan and Tiger 17 against bacterial infections and in boosting hemostasis. Cytocompatibility data verified the peptide-modified mats safety. Croslinked 90/10 PVA/CA mats were deemed the most promising combination due to their moderate hydrophilicity and permeabilities, swelling capacity, and high yields of peptide loading.

Antibacterial biomaterials for skin wound dressing

Bacterial infection and the ever-increasing bacterial resistance have imposed severe threat to human health. And bacterial contamination could significantly menace the wound healing process. Considering the sophisticated wound healing process, novel strategies for skin tissue engineering are focused on the integration of bioactive ingredients, antibacterial agents included, into biomaterials with different morphologies to improve cell behaviors and promote wound healing. However, a comprehensive review on anti-bacterial wound dressing to enhance wound healing has not been reported. In this review, various antibacterial biomaterials as wound dressings will be discussed. Different kinds of antibacterial agents, including antibiotics, nanoparticles (metal and metallic oxides, light-induced antibacterial agents), cationic organic agents, and others, and their recent advances are summarized. Biomaterial selection and fabrication of biomaterials with different structures and forms, including films, hydrogel, electrospun nanofibers, sponge, foam and three-dimension (3D) printed scaffold for skin regeneration, are elaborated discussed. Current challenges and the future perspectives are presented in this multidisciplinary field. We envision that this review will provide a general insight to the elegant design and further refinement of wound dressing.

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.

Cotton Cellulose-Derived Hydrogel and Electrospun Fiber as Alternative Material for Wound Dressing Application

Cotton has been recognized as a useful biomaterial over decades, and it has been widely applied in the textile industry. However, a large amount of cotton waste is generated during the manufacturing processes, but it has been considered as a low-value product. With high content of cellulose remaining in cotton waste, our study focuses on transforming cotton cellulose into a valuable product. Cellulose was extracted from cotton waste and modified into two main materials for wound dressing application: hydrogel-based water absorbent materials and electrospun composite nanofibers. In order to enhance the water absorption, carboxymethyl cellulose (CMC), the modified cellulose with functional group prone to interact with water molecules, has been developed in this study. The hydrogel-based CMC was created by using the chemical cross-linking reaction of epichlorohydrin (ECH). The hydrogel demonstrated the swelling and reswelling ability by 1718 ± 137% and 97.95 ± 9.76%, respectively. Meanwhile, cellulose/PEG in trifluoroacetic acid (TFA) was successfully fabricated as nonwoven composite by a conventional electrospinning technique. The fabrics provided highly appropriated properties as wound dressing, including the following: water absorption was up to 1300 times and water vapor permeability controlled in the range of 2163–2285 g·m⁻²·day⁻¹. This showed the preliminary information for recovering cotton waste into valuable products.

Zein adsorbents with micro/nanofibrous membrane structure for removal of oils, organic dyes, and heavy metal ions in aqueous solution

Developing multi-functional media for effectively removing different contaminants coexisted in wastewater system is highly desired. Herein, zein, a natural protein possessing abundant functional groups in molecule, is chosen to be fabricated into micro/nanofibrous membranes as adsorbents and separation media. Zein fibers with novel groove ribbon structures, which possess better structural characteristics, are designed for obtaining good adsorption performance. The adsorption performances of zein fiber membranes are evaluated. The results show that zein fiber membranes have the adsorption capacities up to 94 g/g for motor oil, 168 mg/g for Congo red, and 189 mg/g for Pb²⁺ ion for 1000 mg/L initial solution concentration, showing considerable competitiveness as compared with the reported adsorbents. The zein membrane with groove ribbon fiber morphology exhibits optimal adsorption capability and can be attractive multi-functional separation media.

A Comparative Study of an Anti-Thrombotic Small-Diameter Vascular Graft with Commercially Available e-PTFE Graft in a Porcine Carotid Model

Background:

We have designed a reinforced drug-loaded vascular graft composed of polycaprolactone (PCL) and polydioxanone (PDO) via a combination of electrospinning/3D printing approaches. To evaluate its potential for clinical application, we compared the in vivo blood compatibility and performance of PCL/PDO + 10%DY grafts doped with an antithrombotic drug (dipyridamole) with a commercial expanded polytetrafluoroethylene (e-PTFE) graft in a porcine model.

Methods:

A total of 10 pigs (weight: 25–35 kg) were used in this study. We made a new 5-mm graft with PCL/PDO composite nanofiber via the electrospinning technique. We simultaneously implanted a commercially available e-PTFE graft (n = 5) and our PCL/PDO + 10%DY graft (n = 5) into the carotid arteries of the pigs. No anticoagulant/antiplatelet agent was administered during the follow-up period, and ultrasonography was performed weekly to confirm the patency of the two grafts in vivo. Four weeks later, we explanted and compared the performance of the two grafts by histological analysis and scanning electron microscopy (SEM).

Results:

No complications, such as sweating on the graft or significant bleeding from the needle hole site, were seen in the PCL/PDO + 10%DY graft immediately after implantation. Serial ultrasonographic examination and immunohistochemical analysis demonstrated that PCL/PDO + 10%DY grafts showed normal physiological blood flow and minimal lumen reduction, and pulsed synchronously with the native artery at 4 weeks after implantation. However, all e-PTFE grafts occluded within the study period. The luminal surface of the PCL/PDO + 10%DY graft in the transitional zone was fully covered with endothelial cells as observed by SEM.

Conclusion:

The PCL/PDO + 10%DY graft was well tolerated, and no adverse tissue reaction was observed in porcine carotid models during the short-term follow-up. Colonization of the graft by host endothelial and smooth muscle cells coupled with substantial extracellular matrix production marked the regenerative capability. Thus, this material may be an ideal substitute for vascular reconstruction and bypass surgeries. Long-term observations will be necessary to determine the anti-thrombotic and remodeling potential of this device.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13770-021-00422-4.

Protein-Based Systems for Topical Antibacterial Therapy

Recently, proteins are gaining attention as potential materials for antibacterial therapy. Proteins possess beneficial properties such as biocompatibility, biodegradability, low immunogenic response, ability to control drug release, and can act as protein-mimics in wound healing. Different plant- and animal-derived proteins can be developed into formulations (films, hydrogels, scaffolds, mats) for topical antibacterial therapy. The application areas for topical antibacterial therapy can be wide including bacterial infections in the skin (e.g., acne, wounds), eyelids, mouth, lips, etc. One of the major challenges of the healthcare system is chronic wound infections. Conventional treatment strategies for topical antibacterial therapy of infected wounds are inadequate, and the development of newer and optimized formulations is warranted. Therefore, this review focuses on recent advances in protein-based systems for topical antibacterial therapy in infected wounds. The opportunities and challenges of such protein-based systems along with their future prospects are discussed.

Adsorption, and controlled release of doxorubicin from cellulose acetate/polyurethane/multi-walled carbon nanotubes composite nanofibers

The cellulose acetate (CA)/poly (ε-caprolactone diol)/poly (tetramethylene ether) glycol-polyurethane (PCL-Diol/PTMG-PU)/multi-walled carbon nanotubes (MWCNTs) composite nanofibers were prepared via two-nozzle electrospinning on both counter sides of the collector. The performance of synthesized composite nanofibers was investigated as an environmental application and anticancer delivery system for the adsorption/release of doxorubicin (DOX). The synergic effect of MWCNTs and DOX incorporated into the nanofibers was investigated against LNCaP prostate cancer cells. The status of MWCNTs and DOX in composite nanofibers was demonstrated by SEM, FTIR and UV-vis determinations. The adsorption tests using nanofibrous adsorbent toward DOX sorption was evaluated under various DOX initial concentrations (100-2000 mg l^-1), adsorption times (5-120 min), and pH values (pH:2-9). Due to the fitting of isotherm and kinetic data with Redlich-Peterson and pseudo-second order models, both chemisorption and surface adsorption of DOX molecules mechanisms have been predicted. The drug release from both nanofibers and MWCNTs-loaded nanofibers was compared. The better drug sustained release profiles verified in the presence of composite nanofibers. LNCaP prostate cancer and L929 normal cells were treated to investigate the cytotoxicity and compatibility of synthesized composite nanofibers. The apoptosis/necrosis of hybrid nanofibers and MWCNTs loaded-nanofibers was investigated. The obtained results demonstrated the synergic effects of MWCNTs and DOX loaded-nanofibers on the LNCaP prostate cancer cells death.

Biomedical applications of carbohydrate-based polyurethane: From biosynthesis to degradation

The foremost common natural polymers are carbohydrate-based polymers or polysaccharides, having a long chain of monosaccharide or disaccharide units linked together via a glycosidic linkage to form a complex structure. There are several uses of carbohydrate-based polymers in biomedical sector due to its attractive features including less toxicity, biocompatibility, biodegradability, high reactivity, availability, and relatively inexpensive. The aim of our study was to explore the synthetic approaches for the preparation of numerous carbohydrate-based polyurethanes (PUs) and their wide range of pharmaceutical and biomedical applications. The data summarized in this study shows that the addition of carbohydrates in the structural skeleton of PUs not only improve their suitability but also effect the applicability for employing them in biological applications. Carbohydrate-based units are incorporated into the PUs, which is the most convenient method for the synthesis of novel biocompatible and biodegradable carbohydrate-based PUs to use in various biomedical applications.

Sandwich structure Aloin-PVP/Aloin-PVP-PLA/PLA as a wound dressing to accelerate wound healing

We have prepared a new type of Aloin/Polyvinylpyrrolidone (PVP)-Aloin/PVP/polylactic acid (PLA)-PLA sandwich nanofiber membrane (APP), to achieve a time-regulated biphasic drug release behavior, used for hemostasis, antibacterial activity and accelerated wound healing. We tested the water absorption capacity, water contact angle, tensile strength, thermogravimetric analysis, Fourier transform infrared spectroscopy and in vitro drug release of the prepared material, as well as analyzed the morphology of the nanofiber membrane with a scanning electron microscope. In the wound healing experiment, the wound healing rate of APP on the 15th day was 96.67%, and it demonstrated excellent antibacterial activity by the disc diffusion method, showing superior antibacterial activity against Gram-negative bacteria. The skin defect model on the back of mice showed that APP nanofibers significantly induced granulation tissue growth, collagen deposition and epithelial tissue remodeling. Current research shows that the prepared composite nanofibers can quickly stop bleeding and can effectively promote wound healing.

Flow chart for the preparation of “sandwich” nanofiber membranes.

Polyurethane Foam Incorporated with Nanosized Copper-Based Metal-Organic Framework: Its Antibacterial Properties and Biocompatibility

Polyurethane foams (PUFs) have attracted attention as biomaterials because of their low adhesion to the wound area and suitability as biodegradable or bioactive materials. The composition of the building blocks for PUFs can be controlled with additives, which provide excellent anti-drug resistance and biocompatibility. Herein, nanosized Cu-BTC (copper(II)-benzene-1,3,5-tricarboxylate) was incorporated into a PUF via the crosslinking reaction of castor oil and chitosan with toluene-2,4-diisocyanate, to enhance therapeutic efficiency through the modification of the surface of PUF. The physical and thermal properties of the nanosized Cu-BTC-incorporated PUF (PUF@Cu-BTC), e.g., swelling ratio, phase transition, thermal gravity loss, and cell morphology, were compared with those of the control PUF. The bactericidal activities of PUF@Cu-BTC and control PUF were evaluated against Pseudomonas aeruginosa, Klebsiella pneumoniae, and methicillin-resistant Staphylococcus aureus. PUF@Cu-BTC exhibited selective and significant antibacterial activity toward the tested bacteria and lower cytotoxicity for mouse embryonic fibroblasts compared with the control PUF at a dose of 2 mg mL-1. The Cu(II) ions release test showed that PUF@Cu-BTC was stable in phosphate buffered saline (PBS) for 24 h. The selective bactericidal activity and low cytotoxicity of PUF@Cu-BTC ensure it is a candidate for therapeutic applications for the drug delivery, treatment of skin disease, and wound healing.

Zein as a versatile biopolymer: different shapes for different biomedical applications

In recent years, the interest regarding the use of proteins as renewable resources has deeply intensified. The strongest impact of these biomaterials is clear in the field of smart medicines and biomedical engineering. Zein, a vegetal protein extracted from corn, is a suitable biomaterial for all the above-mentioned purposes due to its biodegradability and biocompatibility. The controlled drug delivery of small molecules, fabrication of bioactive membranes, and 3D assembly of scaffold for tissue regeneration are just some of the topics now being extensively investigated and reported in the literature. Herein, we review the recent literature on zein as a biopolymer and its applications in the biomedical world, focusing on the different shapes and sizes through which it can be manipulated.

Zein a versatile biomaterial in the biomedical field. Easy to chemically functionalize with good emulsification properties, can be employed in drug delivery, fabrication of bioactive membranes and 3D scaffolds for tissue regeneration.

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.

Acrylate-endcapped urethane-based hydrogels: An in vivo study on wound healing potential

Improving wound healing by developing innovative dressing materials has been an important focus over the past few years in the biomedical field. In this regard, the current study focuses on developing new dressings based on acrylate-endcapped urethane-based polymers (AUPs). The materials have been processed into films and electrospun mats. Exudate uptake capacity, mechanical properties and fiber morphology were evaluated herein. The results showed superior uptake capacity of both films and mats when compared to Aquacel®Ag, Exufiber® and Help®. Addition of a high molar mass poly(ethylene glycol) to the AUP polymers benefits both the film and electrospun dressings in terms of flexibility and elongation. An in vivo study was conducted to assess the wound healing properties of these dressings on an acute wound model induced to rats. A macroscopic evaluation indicated that wound contraction and wound fraction percentages were improved significantly in case of the AUP-materials when compared to both the positive (Aquacel®Ag) and negative (Exufiber® and Help®) controls. A histopathological assay, to underline the changes noticed on a macroscopical level, was also performed. The data obtained proved that the developed dressings are beneficial towards tissue regeneration and accelerated wound healing. These findings offer a practical yet adequate strategy for the fabrication of acrylate-endcapped urethane-based materials for wound healing applications.