Fabrication of scaffold based on gelatin and polycaprolactone (PCL) for wound dressing application

Preparing gelatin-containing polycaprolactone / polylactic acid nanofibrous membranes for periodontal tissue regeneration using side-by-side electrospinning technology

Electrospinning technology has recently attracted increased attention in the biomedical field, and preparing various cellulose nanofibril membranes for periodontal tissue regeneration has unique advantages. However, the characteristics of using a single material tend to make it challenging to satisfy the requirements for a periodontal barrier film, and the production of composite fibrous membranes frequently impacts the quality of the final fiber membrane due to the influence of miscibility between different materials. In this study, nanofibrous membranes composed of polylactic acid (PLA) and polycaprolactone (PCL) fibers were fabricated using side-by-side electrospinning. Different concentrations of gelatin were added to the fiber membranes to improve their hydrophilic properties. The morphological structure of the different films as well as their composition, wettability and mechanical characteristics were examined. The results show that PCL/PLA dual-fibrous composite membranes with an appropriate amount of gelatin ensures sufficient mechanical strength while obtaining improved hydrophilic properties. The viability of L929 fibroblasts was evaluated using CCK-8 assays, and cell adhesion on the scaffolds was confirmed by scanning electron microscopy and by immunofluorescence assays. The results demonstrated that none of the fibrous membranes were toxic to cells and the addition of gelatin improved cell adhesion to those membranes. Based on our findings, adding 30% gelatin to the membrane may be the most appropriate content for periodontal tissue regeneration, considering the scaffold's mechanical qualities, hydrophilic properties and biocompatibility. In addition, the PCL-gelatin/PLA-gelatin dual-fibrous membranes prepared using side-by-side electrospinning technology have potential applications for tissue engineering.

Preparation and characterization of amphiphilic, biodegradable, waterborne polyurethanes without using organic solvent and catalyst

Traditionally, waterborne polyurethanes (WPUs) are prepared using toxic organic solvents and catalysts. These WPUs are non-biodegradable and are buried or incinerated after the expiration date. This has adverse effects on the environment and human health, which limits the applications of WPUs. Herein, a special synthetic method was developed for biodegradable waterborne polyurethane (BWPU) by adding hydrophilic prepolymers into WPU prepolymers without using organic solvents and catalysts. Different proportions of polyethylene glycol (PEG) were introduced into polycaprolactone (PCL)-based BWPUs to improve the comprehensive properties. Results showed that as the PEG content was increased from 0 to 16 wt%, the solid content of BWPU increased from 34.8 wt% to 53.1 wt%, while the tensile strength and Young's modulus of BWPU films increased from 21.81 MPa to 56.83 MPa and 8.08 MPa to 19.4 MPa, respectively. However, the elongation at break did not decrease significantly, but still reached 827.17%. With an increase in PEG content, the crystallinity and phase separation decreased, while the hydrophilicity and surface energy increased for BWPU films. In addition, the prepared BWPUs had good biodegradability in PBS/lipase solution. The mass loss of BWPU without PEG reached 6.3 wt% after 4 weeks of degradation, whereas the mass losses of BWPUs with PEG reached 2.3-4.3 wt%. Obviously, the introduction of PEG did not increase biodegradability. Thus, the higher the PCL content, the faster the biodegradation rate. This work would provide an effective method for the preparation of ecofriendly biodegradable BWPU with excellent comprehensive properties.

Advancements in wound healing: integrating biomolecules, drug delivery carriers, and targeted therapeutics for enhanced tissue repair

Wound healing, a critical biological process vital for tissue restoration, has spurred a global market exceeding $15 billion for wound care products and $12 billion for scar treatment. Chronic wounds lead to delayed or impaired wound healing. Natural bioactive compounds, prized for minimal side effects, stand out as promising candidates for effective wound healing. In response, researchers are turning to nanotechnology, employing the encapsulation of these agents into drug delivery carriers. Drug delivery system will play a crucial role in enabling targeted delivery of therapeutic agents to promote tissue regeneration and address underlying issues such as inflammation, infection, and impaired angiogenesis in chronic wound healing. Drug delivery carriers offer distinct advantages, exhibiting a substantial ratio of surface area to volume and altered physical and chemical properties. These carriers facilitate sustained and controlled release, proving particularly advantageous for the extended process of wound healing, that typically comprise a diverse range of components, integrating both natural and synthetic polymers. Additionally, they often incorporate bioactive molecules. Despite their properties, including poor solubility, rapid degradation, and limited bioavailability, various natural bioactive agents face challenges in clinical applications. With a global research, emphasis on harnessing nanomaterial for wound healing application, this research overview engages advancing drug delivery technologies to augment the effectiveness of tissue regeneration using bioactive molecules. Recent progress in drug delivery has poised to enhance the therapeutic efficacy of natural compounds in wound healing applications.

Smart Nanofibrous Hydrogel Wound Dressings for Dynamic Infection Diagnosis and Control: Soft but Functionally Rigid

Chronic wounds, such as burns and diabetic foot ulcers, pose significant challenges to global healthcare systems due to prolonged hospitalization and increased costs attributed to susceptibility to bacterial infections. The conventional use of antibiotic-loaded and metal-impregnated dressings exacerbates concerns related to multidrug resistance and skin argyrosis. In response to these challenges, our research introduces a unique approach utilizing antibiotic-free smart hydrogel wound dressings with integrated infection eradication and diagnostic capabilities. Electrospinning stands out as a method capable of producing hydrogel nanofibrous materials possessing favorable characteristics for treating wounds and detecting infections under conditions utilizing sustainable materials. In this study, innovative dressings are fabricated through electrospinning polycaprolactone (PCL)/gelatin (GEL) hybrid hydrogel nanofibers, incorporating pDA as a cross-linker, εPL as a broad-spectrum antimicrobial agent, and anthocyanin as a pH-responsive probe. The developed dressings demonstrate exceptional antioxidant (>90% radical scavenging) and antimicrobial properties (95-100% killing). The inclusion of polyphenols/flavonoids and εPL leads to absolute bacterial eradication, and in vitro assessments using HaCaT cells indicate increased cell proliferation, decreased reactive oxygen species (ROS) production, and enhanced cell viability (100% Cell viability). The dressings display notable alterations in color that correspond to different wound conditions. Specifically, they exhibit a red/violet hue under healthy wound conditions (pH 4-6.5) and a green/blue color under unhealthy wound conditions (pH > 6.5). These distinctive color changes provide valuable insights into the versatile applications of the dressings in the care and management of wounds. Our findings suggest that these antibiotic-free smart hydrogel wound dressings hold promise as an effective and sustainable solution for chronic wounds, providing simultaneous infection control and diagnostic monitoring. This research contributes to advancing the field of wound care, offering a potential paradigm shift in the development of next-generation wound dressings.

Chlorinated-based bioceramics incorporated in polycaprolactone membranes

The development of bioactive membranes with bone repair properties is great interest in the field of tissue engineering. In this study, we aimed to fabricate and characterize a composite membrane composed of sol-gel synthesized bioceramics and electrospun polycaprolactone (PCL) fibers for bone tissue regeneration applications. The bioceramics were prepared using the sol-gel method with nitrate (N) and chloride (CL) as precursors. PCL and bioceramic solutions were electrospun to obtain ultrafine fiber mats. Raman spectroscopy, x-ray diffraction (XRD), Fourier Transform Infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM) were used to characterize the materials. The results showed that both chlorinated and non-chlorinated bioceramics contained NBOs (non-bridge bonds) and crystallized the α-wollastonite phase, with the chlorinated version doing so at lower temperatures. In vitro tests were performed to evaluate cytotoxicity, cell adhesion, and mineralized matrix formation on the membranes. The composite membranes showed improved cell viability and promoted mineralization nodules formation. This study presents a promising approach for the development of bioactive membranes for bone tissue engineering, with potential applications in bone regeneration therapies.

Effect of Gelatin Coating and GO Incorporation on the Properties and Degradability of Electrospun PCL Scaffolds for Bone Tissue Regeneration

Polymer-based nanocomposites such as polycaprolactone/graphene oxide (PCL/GO) have emerged as alternatives for bone tissue engineering (BTE) applications. The objective of this research was to investigate the impact of a gelatin (Gt) coating on the degradability and different properties of PCL nanofibrous scaffolds fabricated by an electrospinning technique with 1 and 2 wt% GO. Uniform PCL/GO fibers were obtained with a beadless structure and rough surface. PCL/GO scaffolds exhibited an increase in their crystallization temperature (Tc), attributed to GO, which acted as a nucleation agent. Young's modulus increased by 32 and 63% for the incorporation of 1 and 2 wt% GO, respectively, in comparison with neat PCL. A homogeneous Gt coating was further applied to these fibers, with incorporations as high as 24.7 wt%. The introduction of the Gt coating improved the hydrophilicity and degradability of the scaffolds. Bioactivity analysis revealed that the hydroxyapatite crystals were deposited on the Gt-coated scaffolds, which made them different from their uncoated counterparts. Our results showed the synergic effect of Gt and GO in enhancing the multifunctionality of the PCL, in particular the degradability rate, bioactivity, and cell adhesion and proliferation of hGMSC cells, making it an interesting biomaterial for BTE.

Photocrosslinkable gelatin-treated dentin matrix hydrogel as a novel pulp capping agent for dentin regeneration: I. synthesis, characterizations and grafting optimization

BACKGROUND

In recent years, treated dentin matrix (TDM) has been introduced as a bioactive hydrogel for dentin regeneration in DPC. However, no study has introduced TDM as a photocrosslinkable hydrogel with a natural photoinitiating system. Therefore, the present study aimed to explore the synthesis, characterizations and grafting optimization of injectable gelatin- glycidyl methacrylate (GMA)/TDM hydrogels as a novel photocrosslinkable pulp capping agent for dentin regeneration.

METHODS

G-GMA/TDM hydrogel was photocrosslinked using a new two-component photoinitiating system composed of riboflavin as a photoinitiator under visible light and glycine as a first time coinitiator with riboflavin. The grafting reaction conditions of G-GMA/TDM e.g. GMA concentration and reaction time were optimized. The kinetic parameters e.g. grafting efficiency (GE) and grafting percentage (GP%) were calculated to optimize the grafting reaction, while yield (%) was determined to monitor the formation of the hydrogel. Moreover, G-GMA/TDM hydrogels were characterized by swelling ratio, degradation degree, and cytotoxicity. The instrumental characterizations e.g. FTIR, 1H-NMR, SEM and TGA, were investigated for verifying the grafting reaction. Statistical analysis was performed using F test (ANOVA) and Post Hoc Test (P = 0.05).

RESULTS

The grafting reaction dramatically increased with an increase of both GMA concentration and reaction time. It was realized that the swelling degree and degradation rate of G-GMA/TDM hydrogels were significantly reduced by increasing the GMA concentration and prolonging the reaction time. When compared to the safe low and moderate GMA content hydrogels (0.048, 0.097 M) and shorter reaction times (6, 12, 24 h), G-GMA/TDM with high GMA contents (0.195, 0.391 M) and a prolonged reaction time (48 h) demonstrated cytotoxic effects against cells using the MTT assay. Also, the morphological surface of G-GMA/TDM freeze-dried gels was found more compacted, smooth and uniform due to the grafting process. Significant thermal stability was noticed due to the grafting reaction of G-GMA/TDM throughout the TGA results.

CONCLUSIONS

G-GMA/TDM composite hydrogel formed by the riboflavin/glycine photoinitiating system is a potential bioactive and biocompatible system for in-situ crosslinking the activated-light pulp capping agent for dentin regeneration.

PGS/Gelatin Nanocomposite Electrospun Wound Dressing

Infectious diabetic wounds can result in severe injuries or even death. Biocompatible wound dressings offer one of the best ways to treat these wounds, but creating a dressing with a suitable hydrophilicity and biodegradation rate can be challenging. To address this issue, we used the electrospinning method to create a wound dressing composed of poly(glycerol sebacate) (PGS) and gelatin (Gel). We dissolved the PGS and Gel in acetic acid (75 v/v%) and added EDC/NHS solution as a crosslinking agent. Our measurements revealed that the scaffolds' fiber diameter ranged from 180.2 to 370.6 nm, and all the scaffolds had porosity percentages above 70%, making them suitable for wound healing applications. Additionally, we observed a significant decrease (p < 0.05) in the contact angle from 110.8° ± 4.3° for PGS to 54.9° ± 2.1° for PGS/Gel scaffolds, indicating an improvement in hydrophilicity of the blend scaffold. Furthermore, our cell viability evaluations demonstrated a significant increase (p < 0.05) in cultured cell growth and proliferation on the scaffolds during the culture time. Our findings suggest that the PGS/Gel scaffold has potential for wound healing applications.

Gelatin/calcium chloride electrospun nanofibers for rapid hemostasis

Blood coagulation is the body's main defense to bleeding caused by trauma and is divided into endogenous and exogenous pathways. Calcium ions play a very important role in the process of blood coagulation, as the ions activate the many enzymes that are required for coagulation. In this paper, gelatin hemostatic membranes containing calcium ions were prepared by electrospinning. The fibers were characterized with scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction. The biocompatibility and coagulation processes using the calcium ion-containing gelatin fibrous membranes were evaluated in vitro with dynamic whole-blood coagulation tests, hemolysis tests, coagulation time tests, and platelet adhesion tests. It was demonstrated that the calcium ion-containing gelatin membranes had lower hemolysis rates and shorter clotting times than commercially available hemostatic sponges and hemostatic gauzes. In vivo hemostasis experiments were also conducted on the tail vein and liver of mice. Animal experiments demonstrated that the incorporation of calcium ions into the electrospun gelatin membranes promoted platelet aggregation, ensured adhesion of the electrospun membrane to the wound and reduced the bleeding volume and hemostasis time. The composite calcium ion-gelatin electrospun membranes exhibited good in vivo and in vitro hemostatic abilities and accelerated blood clotting by stimulating the coagulation pathway to promote platelet aggregation at the wounds and the formation of mature blood clots for a new approach for acute trauma treatment.

Preparation of porous PCL-PEG-PCL scaffolds using supercritical carbon dioxide

In this study, the Supercritical Carbon Dioxide (scCO₂) gas foaming procedure was used in the preparation of scaffolds containing the model drug dexamethasone (DXMT). The method used did not include an organic solvent thus making it a safe method. The ring-opening polymerization of PCL-PEG-PCL (PCEC) triblock was conducted using an organocatalyst [1,8 diazabicyclo [5.4.0] undec-7-ene (DBU)]. After mixing 5.0 g of DXMT with 50.0 g of PCEC, hydraulic pressure was applied to compress the mixed powder into disc-like tablets. The tablet-like scaffold of the triblock containing DXMT was inserted into a scCO₂ gas-foaming device. The peak porosity percentage of the synthesized triblock was found to be 55.58 %. Pressure, temperature, soaking time and the time required to depressurize were recorded as 198 bar, 50 °C, 2.0 h, and 28 min respectively. After treatment with scCO₂, the scaffolds experienced an almost full release of DXMT in vitro after 30 days (83.74 ± 1.54 % vs 52.24 ± 2.03 % before scCO₂ treatment). In conclusion, the results proved that the scCO₂ gas foaming procedure could be employed for constructing modifiable PCEC scaffolds with plausible porosity and structural and morphological features which can manipulate drug release.

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.

Advances in the Preparation of Nanofiber Dressings by Electrospinning for Promoting Diabetic Wound Healing

Chronic diabetic wounds are one of the main complications of diabetes, manifested by persistent inflammation, decreased epithelialization motility, and impaired wound healing. This will not only lead to the repeated hospitalization of patients, but also bear expensive hospitalization costs. In severe cases, it can lead to amputation, sepsis or death. Electrospun nanofibers membranes have the characteristics of high porosity, high specific surface area, and easy functionalization of structure, so they can be used as a safe and effective platform in the treatment of diabetic wounds and have great application potential. This article briefly reviewed the pathogenesis of chronic diabetic wounds and the types of dressings commonly used, and then reviewed the development of electrospinning technology in recent years and the advantages of electrospun nanofibers in the treatment of diabetic wounds. Finally, the reports of different types of nanofiber dressings on diabetic wounds are summarized, and the method of using multi-drug combination therapy in diabetic wounds is emphasized, which provides new ideas for the effective treatment of diabetic wounds.

Comparison of Origanum Essential Oil Chemical Compounds and Their Antibacterial Activity against Cronobacter sakazakii

Origanum vulgare L. (oregano) is an aromatic plant with wide applications in the food and pharmaceutical industries. Cronobacter sakazakii, which has a high detection rate in powdered infant formula, adversely impacts susceptible individuals. Oregano essential oil (OEO) is a natural antibacterial agent that can be used to fight bacterial contamination. Here, OEO chemical compounds from eight oregano varieties were analyzed by gas chromatography–mass spectrometry and their antibacterial properties were assessed. The eight OEOs were clustered into two groups and were more diverse in group 2 than in group 1. Six compounds, including p-cymene, 3-thujene, γ-terpinene, thymol, carvacrol, and caryophyllene, were shared by eight OEOs. Among the eight oregano varieties, OEOs from O. vulgare sc2 had the strongest antibacterial activity against C. sakazaki, with the inhibition zone of 18.22mm. OEOs from O. vulgare jx, O. ‘Nvying’, O. vulgare ‘Ehuang’, and O. vulgare ssp. virens were also potent. Moreover, the antibacterial activity of OEOs was positively correlated with the relative content of thymol. As the main OEO antibacterial compound, thymol affected the normal growth and metabolism of C. sakazakii cells by destroying the bacterial membrane and decreasing the intracellular ATP concentration. Thus, in light of the antibacterial activity detected in the OEOs from the eight oregano varieties, this study provides a theoretical foundation for oregano cultivar management and development.

Essential Oils as Antimicrobial Active Substances in Wound Dressings

Wound dressings for skin lesions, such as bedsores or pressure ulcers, are widely used for many patients, both during hospitalization and in subsequent treatment at home. To improve the treatment and shorten the healing time and, therefore, the cost, numerous types of wound dressings have been developed by manufacturers. Considering certain inconveniences related to the intolerance of some patients to antibiotics and the antimicrobial, antioxidant, and curative properties of certain essential oils, we conducted research by incorporating these oils, based on polyvinyl alcohol/ polyvinyl pyrrolidone (PVA/PVP) biopolymers, into dressings. The objective of this study was to study the potential of a polymeric matrix for wound healing, with polyvinyl alcohol as the main material and polyvinyl pyrrolidone and hydroxypropyl methylcellulose (HPMC) as secondary materials, together with additives (plasticizers poly(ethylene glycol) (PEG) and glycerol), stabilizers (Zn stearate), antioxidants (vitamin A and vitamin E), and four types of essential oils (fennel, peppermint, pine, and thyme essential oils). For all the studied samples, the combining compatibility, antimicrobial, and cytotoxicity properties were investigated. The obtained results demonstrated a uniform morphology for almost all the samples and adequate barrier properties for contact with suppurating wounds. The results show that the obtained samples containing essential oils have a good inhibitory effect on, or antimicrobial properties against, Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, and Candida albicans ATCC 10231. The MTT assay showed that the tested samples were not toxic and did not lead to cell death. The results showed that the essential oils used provide an effective solution as active substances in wound dressings.

"Jianbing" styling multifunctional electrospinning composite membranes for wound healing

Wound infection and excessive exudate can affect the process of wound healing. However, the disadvantage of the anti-microbial wound dressings is that the biological fluids are ineffectively removed. Inspired by making "Chinese Jianbing", a composite wound nano-dressing was developed consisting of a hydrophilic outer layer (chitosan&polyvinyl alcohol: CTS-PVA) and a hydrophobic inner layer (propolis&polycaprolactone: PRO-PCL) by combining casting and electrospinning methods for effective antibacterial and unidirectional removing excess biofluids. In vitro, the composite wound nano-dressing of PRO-PCL and CTS-PVA (PPCP) could strongly inhibit Pseudomonas aeruginosa. Furthermore, PPCP wound dressing had excellent antioxidant properties and blood coagulation index for effective hemostatic. Importantly, it had a preferable water absorption for removing excess biofluid. In vivo, it had anti-inflammatory properties and promoted collagen Ⅰ preparation, which realized 80% wound healing on day 7. In short, the PPCP wound dressing provides a new direction and option for antibacterial and removes excess biofluid.

Applications of Electrospun Drug-Eluting Nanofibers in Wound Healing: Current and Future Perspectives

Wounds are a consequence of disruption in the structure, integrity, or function of the skin or tissue. Once a wound is formed following mechanical or chemical damage, the process of wound healing is initiated, which involves a series of chemical signaling and cellular mechanisms that lead to regeneration and/or repair. Disruption in the healing process may result in complications; therefore, interventions to accelerate wound healing are essential. In addition to mechanical support provided by sutures and traditional wound dressings, therapeutic agents play a major role in accelerating wound healing. The medicines known to improve the rate and extent of wound healing include antibacterial, anti-inflammatory, and proliferation enhancing agents. Nonetheless, the development of these agents into eluting nanofibers presents the possibility of fabricating wound dressings and sutures that provide mechanical support with the added advantage of local delivery of therapeutic agents to the site of injury. Herein, the process of wound healing, complications of wound healing, and current practices in wound healing acceleration are highlighted. Furthermore, the potential role of drug-eluting nanofibers in wound management is discussed, and lastly, the economic implications of wounds as well as future perspectives in applying fiber electrospinning in the design of wound dressings and sutures are considered and reported.

State-of-the-Art Review of Electrospun Gelatin-Based Nanofiber Dressings for Wound Healing Applications

Electrospun nanofiber materials have been considered as advanced dressing candidates in the perspective of wound healing and skin regeneration, originated from their high porosity and permeability to air and moisture, effective barrier performance of external pathogens, and fantastic extracellular matrix (ECM) fibril mimicking property. Gelatin is one of the most important natural biomaterials for the design and construction of electrospun nanofiber-based dressings, due to its excellent biocompatibility and biodegradability, and great exudate-absorbing capacity. Various crosslinking approaches including physical, chemical, and biological methods have been introduced to improve the mechanical stability of electrospun gelatin-based nanofiber mats. Some innovative electrospinning strategies, including blend electrospinning, emulsion electrospinning, and coaxial electrospinning, have been explored to improve the mechanical, physicochemical, and biological properties of gelatin-based nanofiber mats. Moreover, numerous bioactive components and therapeutic agents have been utilized to impart the electrospun gelatin-based nanofiber dressing materials with multiple functions, such as antimicrobial, anti-inflammation, antioxidation, hemostatic, and vascularization, as well as other healing-promoting capacities. Noticeably, electrospun gelatin-based nanofiber mats integrated with specific functions have been fabricated to treat some hard-healing wound types containing burn and diabetic wounds. This work provides a detailed review of electrospun gelatin-based nanofiber dressing materials without or with therapeutic agents for wound healing and skin regeneration applications.

The Effect of Nanoparticle-Incorporated Natural-Based Biomaterials towards Cells on Activated Pathways: A Systematic Review

The advancement of natural-based biomaterials in providing a carrier has revealed a wide range of benefits in the biomedical sciences, particularly in wound healing, tissue engineering and regenerative medicine. Incorporating nanoparticles within polymer composites has been reported to enhance scaffolding performance, cellular interactions and their physico-chemical and biological properties in comparison to analogue composites without nanoparticles. This review summarized the current knowledge of nanoparticles incorporated into natural-based biomaterials with effects on their cellular interactions in wound healing. Although the mechanisms of wound healing and the function of specific cells in wound repair have been partially described, many of the underlying signaling pathways remain unknown. We also reviewed the current understanding and new insights into the wingless/integrated (Wnt)/β-catenin pathway and other signaling pathways of transforming growth factor beta (TGF-β), Notch, and Sonic hedgehog during wound healing. The findings demonstrated that most of the studies reported positive outcomes of biomaterial scaffolds incorporated with nanoparticles on cell attachment, viability, proliferation, and migration. Combining therapies consisting of nanoparticles and biomaterials could be promising for future therapies and better outcomes in tissue engineering and regenerative medicine.

Natural Fiber-Reinforced Polycaprolactone Green and Hybrid Biocomposites for Various Advanced Applications

Recent developments within the topic of biomaterials has taken hold of researchers due to the mounting concern of current environmental pollution as well as scarcity resources. Amongst all compatible biomaterials, polycaprolactone (PCL) is deemed to be a great potential biomaterial, especially to the tissue engineering sector, due to its advantages, including its biocompatibility and low bioactivity exhibition. The commercialization of PCL is deemed as infant technology despite of all its advantages. This contributed to the disadvantages of PCL, including expensive, toxic, and complex. Therefore, the shift towards the utilization of PCL as an alternative biomaterial in the development of biocomposites has been exponentially increased in recent years. PCL-based biocomposites are unique and versatile technology equipped with several importance features. In addition, the understanding on the properties of PCL and its blend is vital as it is influenced by the application of biocomposites. The superior characteristics of PCL-based green and hybrid biocomposites has expanded their applications, such as in the biomedical field, as well as in tissue engineering and medical implants. Thus, this review is aimed to critically discuss the characteristics of PCL-based biocomposites, which cover each mechanical and thermal properties and their importance towards several applications. The emergence of nanomaterials as reinforcement agent in PCL-based biocomposites was also a tackled issue within this review. On the whole, recent developments of PCL as a potential biomaterial in recent applications is reviewed.

Optimization of PCL Polymeric Films as Potential Matrices for the Loading of Alpha-Tocopherol by a Combination of Innovative Green Processes

Active food packaging represents an innovative way to conceive food packages. The innovation lies in using natural-based and biodegradable materials to produce a system intended to interact with the food product to preserve its quality and shelf-life. Compared to traditional plastics, active packaging is designed and regulated to release substances in a controlled manner, mainly antimicrobial and antioxidant compounds. Conventional technologies are not suitable for treating these natural substances; therefore, the research for innovative and green techniques represents a challenge in this field. The aim of this work is to compare two different polymeric structures: nanofibrous films obtained by electrospinning and continuous films obtained by solvent casting, to identify the best solution and process conditions for subjecting the samples to the supercritical fluids impregnation process (SFI). The supports optimized were functionalized by impregnating alpha-tocopherol using the SFI process. In particular, the different morphologies of the samples both before and after the supercritical impregnation process were initially studied, identifying the limits and possible solutions to obtain an optimization of the constructs to be impregnated with this innovative green technology in the packaging field.

Electrospun Medicated Nanofibers for Wound Healing: Review

With the increasing demand for wound care and treatment worldwide, traditional dressings have been unable to meet the needs of the existing market due to their limited antibacterial properties and other defects. Electrospinning technology has attracted more and more researchers' attention as a simple and versatile manufacturing method. The electrospun nanofiber membrane has a unique structure and biological function similar to the extracellular matrix (ECM), and is considered an advanced wound dressing. They have significant potential in encapsulating and delivering active substances that promote wound healing. This article first discusses the common types of wound dressing, and then summarizes the development of electrospun fiber preparation technology. Finally, the polymers and common biologically active substances used in electrospinning wound dressings are summarized, and portable electrospinning equipment is also discussed. Additionally, future research needs are put forward.

Bioactive Electrospun Fibers of Poly(ε-Caprolactone) Incorporating α-Tocopherol for Food Packaging Applications

Antioxidant activity is an important feature for food contact materials such as packaging, aiming to preserve freshness and retard food spoilage. Common bioactive agents are highly susceptible to various forms of degradation; therefore, protection is required to maintain functionality and bioavailability. Poly(ε-caprolactone) (PCL), a biodegradable GRAS labeled polymer, was used in this study for encapsulation of α-tocopherol antioxidant, a major component of vitamin E, in the form of electrospun fibers. Rheological properties of the fiber forming solutions, which determine the electrospinning behavior, were correlated with the properties of electrospun fibers, e.g., morphology and surface properties. Interactions through hydrogen bonds were evidenced between the two components. These have strong effect on structuration of macromolecular chains, especially at low α-tocopherol amounts, decreasing viscosity and elastic modulus. Intra-molecular interactions in PCL strengthen at high α-tocopherol amounts due to decreased solvation, allowing good structural recovery after cease of mechanical stress. Morphologically homogeneous electrospun fibers were obtained, with ~6 μm average diameter. The obtained fibers were highly hydrophobic, with fast release in 95% ethanol as alternative simulant for fatty foods. This induced good in vitro antioxidant activity and significant in vivo reduction of microbial growth on cheese, as determined by respirometry. Therefore, the electrospun fibers from PCL entrapping α-tocopherol as bioactive agent showed potential use in food packaging materials.

Development of dual crosslinked mumio-based hydrogel dressing for wound healing application: Physico-chemistry and antimicrobial activity

In this study, an antimicrobial mumio-based hydrogel dressing was developed for wound healing application. The mechanism of gel formation was achieved via a double crosslink network formation between gelatin (GT) and polyvinyl alcohol (PVA) using polyethylene glycol diglycidyl ether (PEGDE) and borax as crosslinking agents. To enhance the mechanical integrity of the hydrogel matrix, bacterial cellulose (BC) was integrated into the GT-PVA hydrogel to produce a composite gel dressing. The obtained hydrogel was characterized by FTIR, SEM, TGA, and XRD. Gel fraction, in vitro swelling and degradation as well as compressive modulus properties of the gel dressing were investigated as a function of change in PVA and BC ratios. By increasing the ratios of PVA and BC, the composite dressing showed lower swelling but higher mechanical strength. Comparing to other formulations, the gel with 4 %w/v PVA and 1 %w/v BC demonstrated to be most suitable in terms of stability and mechanical properties. In vitro cell cytotoxicity by MTT assay on human alveolar basal epithelial (A549) cell lines validated the gels as non-toxic. In addition, the mumio-based gel was compared to other formulations containing different bioactive agents of beeswax and cinnamon oil, which were tested for microbial growth inhibition effects against different bacteria (S. aureus and K. pneumoniae) and fungi (C. albicans and A. niger) strains. Results suggested that the gel dressing containing combinations of mumio, beeswax and cinnamon oil possess promising future in the inhibition of microbial infection supporting its application as a suitable dressing for wound healing.