Facile Fabrication of Sandwich Structural Membrane With a Hydrogel Nanofibrous Mat as Inner Layer for Wound Dressing Application

Lysozyme/N-GQD loaded carboxymethyl cellulose hydrogels for healing of excision wounds in Drosophila and Sprague Dawley rats

Delayed healing and fibrosis at the wound site present significant challenges in the wound care industry, often leading to complications such as infections, chronic wounds, and impaired tissue regeneration. Therefore, there is a critical need for advanced wound dressing materials that promote faster healing, prevent bacterial infections, and support effective tissue repair. This study aims to develop a Lysozyme (Lys)-based wound dressing with enhanced wound closure rates by incorporating nitrogen-doped graphene quantum dots (N-GQDs) as a functionalized nanofiller to strengthen its antibacterial properties. The wound dressing, formulated with a carboxymethyl cellulose (CMC) crosslinked polyvinylpyrrolidone (PVP) matrix, creates a porous structure that enhances swelling capacity and water vapor transmission rates (WVTR), while cytotoxicity studies confirm its biocompatibility, showing 100 % cell viability in HCT 116 and MCF7 cell lines. The in vivo wound healing performance of the designed nanocomposite hydrogel reflects complete wound closure in 5 h for Drosophila Melanogaster, aided by the shorter life span and faster metabolic processes in Drosophila, and 14 days in Sprague Dawley rat models. These results qualify the material as a promising candidate for wound dressing applications, bridging the gap between material science and medical science for effective wound management.

Blueberry extract loaded into rice milk/alginate-based hydrogels as pH-sensitive systems to monitor the freshness of minced chicken

Hydrogel beads from rice milk and blueberry (BB) skins were fabricated as novel bio-based pH-sensitive devices. The encapsulation of BB into rice milk/alginate beads was achieved through a simple methodology. The colourimetric response of beads in different pH media was evaluated along with the proof of reusability, showing appropriate reversibility. The evaluation of the stability of BB-loaded beads in accelerated ageing conditions (4, 25 and 40 °C and under visible/UV light) showed high stability of beads (up to 28 days) even in the presence of harsh conditions. The half-time of cyanidin-3-glucoside decreases at high temperatures and under UV light exposure. The sensitivity to ammonia (NH3) and trimethylamine (TMA), as main spoilage volatiles of protein food products, was evaluated. The detection limits (LOD) for NH3 and TMA were 22.4 ppm and 72.1 ppm, respectively. Finally, the hydrogel beads were applied to monitor the spoilage of minced chicken breast. The colour of the beads, changing from dark reddish to green/yellowish and indicative of a high level of amine, could be detected by the naked eye after 3-5 days. This research proposes a sustainable, low-cost, and simple method to fabricate BB-loaded hydrogel beads as a promising tool for intelligent packaging applications.

Quercetin encapsulated polycaprolactone-polyvinylpyrrolidone electrospun membranes as a delivery system for wound healing applications

The present work focuses on the production of electrospun membranes based on Poly(ε-caprolactone) (PCL) and Polyvinylpyrrolidone (PVP) for the topical release of Quercetin (Q). Membranes were prepared at 0.5, 1.0, 3.0, 7.0 and 15 % wt of Quercetin and studied from a morphological, physical, and biological point of view. The scanning electron microscopy (SEM) evidences micrometric dimensions of the fibres with a good dispersion of the functional molecule. The retention degree of liquids was evaluated by testing four different liquid media while the radical scavenging activity of Quercetin-loaded membranes was evaluated through DPPH analysis. The release kinetics of Quercetin highlights the presence of an initial burst followed by slower release up to attaining an equilibrium state, after roughly 50 h, showing the possibility of a fine-tuning of drug release. Diffusion coefficients were then evaluated by using Fick's law. Finally, to verify the actual biocompatibility of the systems produced and the possible application in the repair of tissue injury, the biological activity of Quercetin released from drug-loaded membranes was analysed in an immortalized human keratinocyte cell line HaCaT by a wound healing assay. So, the reported preliminary data confirm the possibility of applying the electrospun Quercetin-loaded PCL-PVP membranes for wound healing applications.

Alginate Microbeads Containing Halloysite and Layered Double Hydroxide as Efficient Carriers of Natural Antimicrobials

The present paper describes the preparation and characterization of novel microbeads from alginate filled with nanoclay such as halloysite nanotubes (HNTs). HNTs were used as support for the growth of layered double hydroxide (LDH) crystals producing a flower-like structure (HNT@LDH). Such nanofiller was loaded with grapefruit seed oil (GO), an active compound with antimicrobial activity, up to 50% wt. For comparison, the beads were also loaded with HNT and LDH separately, and filled with the same amount of GO. The characterization of the filler was performed using XRD and ATR spectroscopy. The beads were analyzed through XRD, TGA, ATR and SEM. The functional properties of the beads, as nanocarriers of the active compound, were investigated using UV-vis spectroscopy. The release kinetics were recorded and modelled as a function of the structural characteristics of the nanofiller.

Gallic Acid-Loaded Sodium Alginate-Based (Polyvinyl Alcohol-Co-Acrylic Acid) Hydrogel Membranes for Cutaneous Wound Healing: Synthesis and Characterization

Traditional wound dressings often cannot treat wounds caused by bacterial infections or other wound types that are insensitive to these wound treatments. Therefore, a biodegradable, bioactive hydrogel wound dressing could be an effective alternative option. The purpose of this study was to develop a hydrogel membrane comprised of sodium alginate, polyvinyl alcohol, acrylic acid, and gallic acid for treating skin wounds. The newly developed membranes were analyzed using Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), sol-gel fraction, porosity, mechanical strength, swelling, drug release and data modelling, polymeric network parameters, biodegradation, and antioxidation (DPPH and ABTS) and antimicrobial activity against Gram-positive and negative bacteria. The results revealed that hydrogel membranes were crosslinked successfully and had excellent thermal stability, high drug loading, greater mechanical strength, and exhibited excellent biodegradation. Additionally, the swelling ability and the porosity of the surface facilitated a controlled release of the encapsulated drug (gallic acid), with 70.34% release observed at pH 1.2, 70.10% at pH 5.5 (normal skin pH), and 86.24% at pH 7.4 (wounds pH) in 48 h. The gallic acid-loaded hydrogel membranes showed a greater area of inhibition against Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli bacteria as well as demonstrated excellent antioxidant properties. Based on Franz cell analyses, the permeation flux of the drug from optimized formulations through mice skin was 92 (pH 5.5) and 110 (pH 7.4) μg/cm²·h^-1. Moreover, hydrogel membranes retained significant amounts of drug in the skin for 24 h, such as 2371 (pH 5.5) and 3300 µg/cm² (pH 7.4). Acute dermal irritation tests in rats showed that hydrogel membranes were nonirritating. Hydrogel membranes containing gallic acid could be an effective option for improving wound healing and could result in faster wound healing.

Polyhexamethylene guanidine hydrochloride modified sodium alginate nonwoven with potent antibacterial and hemostatic properties for infected full-thickness wound healing

The development of multifunctional wound dressings has always been considered as a promising strategy to promote blood coagulation, inhibit bacterial infection, and accelerate wound healing. Herein, an antibacterial and hemostatic dressing (SA-PHMG) was developed based on sodium alginate (SA) nonwoven and polyhexamethylene guanidine hydrochloride (PHMG) through a completely green industrial route, including dipping, padding, and drying. According to studies, SA-PHMG dressings exhibited excellent liquid absorption capacity and water vapor permeability. Moreover, bactericidal assays have demonstrated that SA-PHMG dressings have ideal antibacterial activity against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and mixed bacteria, maintaining potent antibacterial activity even after 10 cycles of antibacterial trials or 50 times of washing or soaping. The in vitro evaluation of the hemostatic effect indicated that the SA-PHMG could significantly promote blood clotting by activating platelets, and in vitro and in vivo hemolysis, cytotoxicity and skin irritation studies demonstrated the ideal biocompatibility of the dressings. In addition, better wound closure and tissue regeneration were recorded using SA-PHMG nonwoven as the dressing based on an infected full-thickness wound model. In conclusion, this antibacterial, hemostatic, biocompatible, and environmentally friendly SA-PHMG nonwoven exhibit the potential for infected wound healing.

Microneedle Array Patch Made of Kangfuxin/Chitosan/Fucoidan Complex Enables Full-Thickness Wound Healing

Skin wound caused by external injury is usually difficult to be cured by conventional topical administration because of its poor drug diffusion across the stratum corneum. It has been recognized that stratum corneum is the major obstacle for transdermal drug delivery. To address this issue, microneedles (MNs) have been developed to penetrate the stratum corneum of the skin and then form micron-sized pores between the epidermis and the dermis layers. As such, biomacromolecule drugs and/or insoluble drug molecules can be allowed for effective transdermal penetration. A multifunctional microneedle array patch that can avoid wound infection and promote tissue remolding has important value for wound healing. Among others, marine polysaccharides have attracted much attention in multifarious biomedical applications due to their excellent (bio)physical and chemical properties. Herein, we developed a microneedle array patch using a blend of kangfuxin (KFX), chitosan (CS), and fucoidan (FD), named KCFMN, for accelerating full-thickness wound healing. The traditional Chinese medicine KFX extracted from Periplaneta americana (PA) has effective bio-functions in promoting wound healing. The macro-/micro-morphology and (bio)physicochemical properties of such composite microneedles were also studied. We showed that the KCFMN patch displayed noticeable antibacterial properties and good cytocompatibility. In particular, the KCFMN patch significantly accelerated the wound healing development in a full-thickness wound in rats by improving the epithelial thickness and collagen deposition. Thus, this versatile KCFMN patch has great prospects as a dressing for full-thickness wound healing.

Antiviral Nanomaterials for Designing Mixed Matrix Membranes

Membranes are helpful tools to prevent airborne and waterborne pathogenic microorganisms, including viruses and bacteria. A membrane filter can physically separate pathogens from air or water. Moreover, incorporating antiviral and antibacterial nanoparticles into the matrix of membrane filters can render composite structures capable of killing pathogenic viruses and bacteria. Such membranes incorporated with antiviral and antibacterial nanoparticles have a great potential for being applied in various application scenarios. Therefore, in this perspective article, we attempt to explore the fundamental mechanisms and recent progress of designing antiviral membrane filters, challenges to be addressed, and outlook.

Polymeric antibacterial materials: design, platforms and applications

Over the past decades, the morbidity and mortality caused by pathogen invasion remain stubbornly high even though medical care has increasingly improved worldwide. Besides, impacted by the ever-growing multidrug-resistant bacterial strains, the crisis owing to the abuse and misuse of antibiotics has been further exacerbated. Among the wide range of antibacterial strategies, polymeric antibacterial materials with diversified synthetic strategies exhibit unique advantages (e.g., their flexible structural design, processability and recyclability, tuneable platform construction, and safety) for extensive antibacterial fields as compared to low molecular weight organic or inorganic antibacterial materials. In this review, polymeric antibacterial materials are summarized in terms of four structure styles and the most representative material platforms to achieve specific antibacterial applications. The superiority and defects exhibited by various polymeric antibacterial materials are elucidated, and the design of various platforms to elevate their efficacy is also described. Moreover, the application scope of polymeric antibacterial materials is summarized with regard to tissue engineering, personal protection, and environmental security. In the last section, the subsequent challenges and direction of polymeric antibacterial materials are discussed. It is highly expected that this critical review will present an insight into the prospective development of antibacterial functional materials.

Multifunctional hydrogels for wound healing: Special focus on biomacromolecular based hydrogels

Hydrogels are widely used for wound healing applications due to their similarity to the native extracellular matrix (ECM) and ability to provide a moist environment. However, lack of multifunctionality and low mechanical properties of previously developed hydrogels may limit their ability to support skin tissue regeneration. Incorporating various biomaterials and nanostructures into the hydrogels is an emerging approach to develop multifunctional hydrogels with new functions that are beneficial for wound healing. These multifunctional hydrogels can be fabricated with a wide range of functions and properties, including antibacterial, antioxidant, bioadhesive, and appropriate mechanical properties. Two approaches can be used for development of multifunctional hydrogel-based dressings; taking the advantages of the chemical composition of biomaterials and addition of nanomaterials or nanostructures. A large number of synthetic and natural polymers, bioactive molecules, or nanomaterials have been used to obtain hydrogel-based dressings with multifunctionality for wound healing applications. In the present review paper, advances in the development of multifunctional hydrogel-based dressings for wound healing have been highlighted.

Preparation and characterization of borosilicate-bioglass-incorporated sodium alginate composite wound dressing for accelerated full-thickness skin wound healing

Full-thickness skin injury is a serious and intractable clinical problem. Wound dressing is urgently needed to treat serious skin defects or induce skin reconstruction. For the first time, we demonstrated a borosilicate bioglass (BBG)-incorporated sodium alginate (SA) wound dressing by a simple and effective technique for accelerated wound healing. The physical and chemical properties, in vitro and in vivo properties of SA-BBG composite wound dressing have been investigated. The results show that the SA-BBG composite dressing possesses good water absorption performance. The boron and silicon ions in BBG can maintain stable and sustained release. Most importantly, the SA-BBG composite wound dressing shows outstanding wound healing ability in full-thickness skin defects in rats. The wounds treated with SA-BBG composite dressing groups had almost closed at day 15. When the ratio of sodium alginate to bioglass in the sponge is 3:1, the wound healing effect is the best. In conclusion, the SA-BBG composite dressing shows great potential for application in skin wound healing and SA3BBG works best.

Antibacterial, Flexible, and Conductive Membrane Based on MWCNTs/Ag Coated Electro-Spun PLA Nanofibrous Scaffolds as Wearable Fabric for Body Motion Sensing

In the present study, flexible and conductive nanofiber membranes were prepared by coating PLA nanofibrous scaffolds with carbon nanotubes and silver nanoparticles. The morphology and structure of the prepared membrane was characterized, as well as its mechanical properties, electrical sensing behavior during consecutive stretching-releasing cycles and human motion detecting performance. Furthermore, the antibacterial properties of the membrane was also investigated. Due to the synergistic and interconnected three-dimensional (3D) conductive networks, formed by carbon nanotubes and silver nanoparticles, the membrane exhibited repeatable and durable strain-dependent sensitivity. Further, the prepared membrane could accurately detect the motions of different body parts. Accompanied with promising antibacterial properties and washing fastness, the prepared flexible and conductive membrane provides great application potential as a wearable fabric for real-time body motion sensing.

Fabrication of Electrospun Polymer Nanofibers with Diverse Morphologies

Fiber structures with nanoscale diameters offer many fascinating features, such as excellent mechanical properties and high specific surface areas, making them attractive for many applications. Among a variety of technologies for preparing nanofibers, electrospinning is rapidly evolving into a simple process, which is capable of forming diverse morphologies due to its flexibility, functionality, and simplicity. In such review, more emphasis is put on the construction of polymer nanofiber structures and their potential applications. Other issues of electrospinning device, mechanism, and prospects, are also discussed. Specifically, by carefully regulating the operating condition, modifying needle device, optimizing properties of the polymer solutions, some unique structures of core⁻shell, side-by-side, multilayer, hollow interior, and high porosity can be obtained. Taken together, these well-organized polymer nanofibers can be of great interest in biomedicine, nutrition, bioengineering, pharmaceutics, and healthcare applications.