Gelatin-based nanofiber membranes loaded with curcumin and borneol as a sustainable wound dressing

Chitosan-carrageenan microbeads containing nano-encapsulated curcumin: Nano-in-micro hydrogels as alternative-therapeutics for resistant pathogens associated with chronic wounds

Antimicrobial resistance is an issue of global relevance for the treatment of chronic wound infections. In this study, nano-in-micro hydrogels (microbeads) of chitosan and κ-carrageenan (CCMBs) containing curcumin-loaded rhamnosomes (Cur-R) were developed. The potential of Cur-R-CCMBs for improving the antibacterial activity and sustained release of curcumin was evaluated. Curcumin-loaded rhamnosomes (rhamnolipids functionalized liposomes) had a mean particle size of 116 ± 7 nm and a surface-charge of -24.5 ± 9.4 mV. The encapsulation efficiency of curcumin increased from 42.83 % ± 0.69 % in Cur-R to 95.24 % ± 3.61 % respectively after their embedding in CCMBs. SEM revealed smooth surface morphology of Cur-R-CCMBs. FTIR spectroscopy confirmed the presence of weak electrostatic and hydrophobic interactions among curcumin, rhamnosomes, and microbeads. Cur-R-CCMBs had demonstrated significant antibacterial activity against multi-drug resistant chronic wound pathogens including Staphylococcus aureus and Pseudomonas aeruginosa. Cur-R-CCMBs also exhibited significantly higher anti-oxidant (76.85 % ± 2.12 %) and anti-inflammatory activity (91.94 % ± 0.41 %) as well as hemocompatibility (4.024 % ± 0.59 %) as compared to pristine microbeads. In vivo infection model of mice revealed significant reduction in the viable bacterial count of S. aureus (∼2.5 log CFU/mL) and P. aeruginosa (∼2 log CFU/mL) for Cur-R-CCMBs after 5 days. Therefore, nano-in-micro hydrogels can improve the overall efficacy of hydrophobic antimicrobials to develop effective alternative-therapeutics against resistant-pathogens associated with chronic wound infections.

Donkey Gelatin and Keratin Nanofibers Loaded with Antioxidant Agents for Wound Healing Dressings

Acute and chronic wounds present a significant healthcare challenge, requiring innovative solutions for effective treatment. The exploitation of natural by-products with advanced cell regeneration potential and plant-based materials, which possess bioactive properties, is an innovative topic in wound management. This study investigates the potential of donkey gelatin and keratin for blending with natural bioactive extracts such as sumac, curcumin, and oak acorn to fabricate antioxidant and antimicrobial nanofibers with accelerated wound healing processes. The fabricated nanofibers possess good in vitro biocompatibility, except for the sumac-based donkey nanofibers, where cell viability significantly dropped to 56.25% (p < 0.05 compared to non-treated cells). The nanofiber dimensions showed structural similarities to human extracellular matrix components, providing an ideal microenvironment for tissue regeneration. The donkey nanofiber-based sumac and curcumin extracts presented a higher dissolution in the first 10 min (74% and 72%). Curcumin extract showed similar antimicrobial and antifungal performances to rivanol, while acorn and sumac extracts demonstrated similar values to each other. In vitro tests performed on murine fibroblast cells demonstrated high migration rates of 89% and 85% after 24 h in the case of acorn and curcumin nanofibers, respectively, underscoring the potential of these nanofibers as versatile platforms for advanced wound care applications.

In vitro and in vivo assessment of curcumin-quercetin loaded multi-layered 3D-nanofibroporous matrix prepared by solution blow-spinning for full-thickness burn wound healing

Burn wounds (BWs) cause impairment of native skin tissue and may cause significant microbial infections that demand immediate care. Curcumin (Cur) and quercetin (Que) exhibit antimicrobial, hemocompatibility, ROS-scavenging, and anti-inflammatory properties. However, its instability, water insolubility, and low biological fluid absorption render it challenging to sustain local Cur and Que doses at the wound site. Therefore, to combat these limitations, we employed blow-spinning and freeze-drying to develop a multi-layered, Cur/Que-loaded gelatin/chitosan/PCL (GCP-Q/C) nanofibroporous (NFP) matrix. Morphological analysis of the NFP-matrix using SEM revealed a well-formed multi-layered structure. The FTIR and XRD plots demonstrated dual-bioactive incorporation and scaffold polymer interaction. Additionally, the GCP-Q/C matrix displayed high porosity (82.7 ± 2.07 %), adequate pore size (∼121 μm), enhanced water-uptake ability (∼675 % within 24 h), and satisfactory biodegradation. The scaffolds with bioactives had a long-term release, increased antioxidant activity, and were more effective against gram-positive (S. aureus) and gram-negative (E. coli) bacteria than the unloaded scaffolds. The in vitro findings of GCP-Q/C scaffolds showed promoted L929 cell growth and hemocompatibility. Additionally, an in vivo full-thickness BW investigation found that an implanted GCP-Q/C matrix stimulates rapid recuperation and tissue regeneration. In accordance with the findings, the Gel/Ch/PCL-Que/Cur NFP-matrix could represent an effective wound-healing dressing for BWs.

Membranes composed of poly(lactic acid)/poly(ethylene glycol) and Ora-pro-nóbis (Pereskia aculeata Miller) extract for dressing applications

Wounds are considered one of the most critical medical conditions that must be managed appropriately due to the psychological and physical stress they cause for patients, as well as creating a substantial financial burden on patients and global healthcare systems. Nowadays, there is a growing interest in developing nanofiber mats loaded with varying plant extracts to meet the urgent need for advanced wound ressings. This study investigated the development and characterization of poly(lactic acid) (PLA)/ poly(ethylene glycol) (PEG) nanofiber membranes incorporated with Ora-pro-nóbis (OPN; 12.5, 25, and 50 % w/w) by the solution-blow-spinning (SBS) technique. The PLA/PEG and PLA/PEG/OPN nanofiber membranes were characterized by scanning electron microscopy (SEM), thermal properties (TGA and DSC), Fourier transform infrared spectroscopy (FTIR), contact angle measurements and water vapor permeability (WVTR). In addition, the mats were analyzed for swelling properties in vitro cell viability, and fibroblast adhesion (L-929) tests. SEM images showed that smooth and continuous PLA/PEG and PLA/PEG/OPN nanofibers were obtained with a diameter distribution ranging from 171 to 1533 nm. The PLA/PEG and PLA/PEG/OPN nanofiber membranes showed moderate hydrophobicity (~109-120°), possibly preventing secondary injuries during dressing removal. Besides that, PLA/PEG/OPN nanofibers exhibited adequate WVTR, meeting wound healing requirements. Notably, the presence of OPN gave the PLA/PEG membranes better mechanical properties, increasing their tensile strength (TS) from 3.4 MPa (PLA/PEG) to 5.3 MPa (PLA/PEG/OPN), as well as excellent antioxidant properties (Antioxidant activity with approximately 45 % oxidation inhibition). Therefore, the nanofiber mats based on PLA/PEG, especially those incorporated with OPN, are promising options for use as antioxidant dressings to aid skin healing.

All-Natural Injectable Antibacterial Hydrogel Enabled by Chitosan and Borneol

Hydrogels with intrinsic antimicrobial capabilities based on natural strategies have been studied as a hot topic in biomedicine. Nevertheless, it is highly challenging to thoroughly develop a bacteriostatic natural hydrogel. Borneol as a traditional Chinese medicine possesses a unique broad-spectrum antibacterial activity under a membrane-breaking mechanism. In this study, a range of fully natural antibacterial hydrogels are designed and synthesized via the Schiff base cross-linking of carboxymethyl chitosan and dialdehyde dextran grafted natural borneol. The borneol with three configurations is hydrophilically modified onto dextran to boost its antibacterial activity. Also, the synergism of hydrophilic-modified borneol groups and positively charged ammonium ions of carboxymethyl chitosan make the hydrogels totally constrict the E. coli and S. aureus growth during 24 h. Furthermore, the hydrogels exhibit good in vitro cytocompatibility through cytotoxicity, protein adhesion, and hemolytic tests. In view of the injectability, the hydrogels can be delivered to the target site through a minimally invasive route. In short, this work offers a potential tactic to develop antibacterial hydrogels for the treatment of topical wound infections.

Sodium alginate/poly(vinyl alcohol)/taxifolin nanofiber mat promoting diabetic wound healing by modulating the inflammatory response, angiogenesis, and skin flora

Diabetes-related ulcers are still a therapeutic problem because of their susceptibility to infection, ongoing inflammation, and diminished vascularization. The design and development of novel dressings are clinically urgent for the treatment of chronic wounds due to diabetic ulcers. In this study, we made taxifolin (TAX) loaded sodium alginate (SA)/poly(vinyl alcohol) (PVA) nanofibers for the treatment of chronic wounds. The SA/PVA/TAX nanofibers that have been created are smooth and bead-free, with good thermal stability, hydrophilicity, and mechanical properties. The release profile indicated a sustained drug release, with a cumulative release rate of 64.6 ± 3.7 % at 24 h. In vitro experiments have shown that SA/PVA/TAX has good antibacterial activity, antioxidant activity, and biocompatibility. In vivo experiments have shown that SA/PVA/TAX exhibits desirable biochemical properties and is involved in the diabetic wound healing process by promoting cell proliferation (Ki67), angiogenesis (CD31, VEGFA), and alleviating inflammation (CD68). Western blotting experiments suggest that SA/PVA/TAX may promote diabetic wound healing by inhibiting the TLR4/NF-κB/NLRP3 signaling pathway and upregulating the expression of VEGFA and PDGFA. The 16S rRNA sequencing results showed that SA/PVA/TAX increased the wound surface flora's diversity and reversed the skin microbiota's structural imbalance. Therefore, SA/PVA/TAX can promote diabetic wound healing by modulating the inflammatory response, angiogenesis, and skin flora and has the potential to be an excellent wound dressing.

Electrospun fibers for the treatment of skin diseases

Skin diseases are among the most common diseases in the global population and with the growth of the aging population, they represent an increasing burden to healthcare systems worldwide. Even though they are rarely life-threatening, the suffering for those affected is high due to the visibility and physical discomfort related to these diseases. Typical symptoms of skin diseases include an inflamed, swollen or itchy skin, and therefore, there is a high demand for effective therapy options. In recent years, electrospinning has attracted considerable interest in the field of drug delivery. The technique allows producing multifunctional drug-loaded fibrous patches from various natural and synthetic polymers with fiber diameters in the nano- and micrometer range, suitable for the treatment of a wide variety of skin diseases. The great potential of electrospun fiber patches not only lies in their tunable drug release properties and the possibility to entrap a variety of therapeutic compounds, but they also provide physical and mechanical protection to the impaired skin area, exhibit a high surface area, allow gas exchange, absorb exudate due to their porous structure and are cytocompatible and biodegradable. In the case of wound healing, cell adhesion is promoted due to the resemblance of the electrospun fibers to the structure of the native extracellular matrix. This review gives an overview of the potential applications of electrospun fibers in skin therapy. In addition to the treatment of bacterial, diabetic and burn wounds, focus is placed on inflammatory diseases such as atopic dermatitis and psoriasis, and therapeutic options for the treatment of skin cancer, acne vulgaris and herpes labialis are discussed. While we aim to emphasize the great potential of electrospun fiber patches for the treatment of skin diseases with this review paper, we also highlight challenges and limitations of current research in the field.

Exploring the recent developments of alginate silk fibroin material for hydrogel wound dressing: A review

Hydrogels, a type of polymeric material capable of retaining water within a three-dimensional network, have demonstrated their potential in wound healing, surpassing traditional wound dressings. These hydrogels possess remarkable mechanical, chemical, and biological properties, making them suitable scaffolds for tissue regeneration. This article aims to emphasize the advantages of alginate, silk fibroin, and hydrogel-based wound dressings, specifically highlighting their crucial functions that accelerate the healing process of skin wounds. Noteworthy functions include self-healing ability, water solubility, anti-inflammatory properties, adhesion, antimicrobial properties, drug delivery, conductivity, and responsiveness to stimuli. Moreover, recent advancements in hydrogel technology have resulted in the development of wound dressings with enhanced features for monitoring wound progression, further augmenting their effectiveness. This review emphasizes the utilization of hydrogel membranes for treating excisional and incisional wounds, while exploring recent breakthroughs in hydrogel wound dressings, including nanoparticle composite hydrogels, stem cell hydrogel composites, and curcumin-hydrogel composites. Additionally, the review focuses on diverse synthesis procedures, designs, and potential applications of hydrogels in wound healing dressings.

Curcumin-loaded Butea monosperma gum-based hydrogel: A new excipient for controlled drug delivery and anti-bacterial applications

The wide spectrum of applications provided by curcumin has attracted researchers worldwide to identify its molecular targets and employ it in various biomedical applications. The present research work focuses on the development of a Butea monosperma gum-based hydrogel encapsulated with curcumin and further employing it for two diverse applications, i.e., drug delivery and anti-bacterial application. A central composite design was utilized for the optimization of significant process variables to achieve maximum swelling. A maximum of 662 % swelling was attained at the initiator (0.06 g), monomer (3 ml), crosslinker (0.08 g), solvent (14 ml), and time (60 s). Furthermore, the characterization of the synthesized hydrogel was performed via FTIR, SEM, TGA, H1-NMR, and XRD analysis. Various important properties like swelling rate under different solutions, water retention capacity, re-swelling capability, porosity, and density measurement suggested that the prepared hydrogel exhibited a highly stable crosslinked network with high porosity (0.23) and density (62.5 g/cm³) values. The encapsulation efficiency of curcumin in the hydrogel was reported to be 93 % and 87.3 %, respectively, wherein BM-g-poly(AA) ~ Cur exhibited excellent sustained pH-responsive site release of curcumin at two different pH values, with the maximum amount of release taking place at pH 7.4 (792 ppm) and a minimum at pH 5 (550 ppm) due to the lesser ionization of the functional groups present in the hydrogel at a lower pH value. Additionally, the results from the pH shock studies indicated our material to be stable and efficient even with fluctuations in pH, resulting in the optimal amount of drug release at each pH range. Furthermore, anti-bacterial studies revealed that the synthesized BM-g-poly(AA) ~ Cur was effective against both gram-negative and gram-positive bacteria, with maximum values of zones of inhibition of 16 mm in diameter, thereby showing the best results in comparison to the already developed matrices to date. As a result, the newly discovered BM-g-poly(AA) ~ Cur properties reflect the hydrogel network's suitability for drug release and anti-bacterial applications.

Mussel-Inspired Multifunctional Hydrogels with Adhesive, Self-Healing, Antioxidative, and Antibacterial Activity for Wound Healing

Antibacterial hydrogel wound dressings with adhesive and antioxidant activity are desirable for treating skin injuries in clinical care. Hereby, a series of multifunctional hydrogel wound dressings with high adhesive, self-healing, antioxidant, and antibacterial activity were designed and fabricated using dopamine (DA) and quercetin (QT). The multifunctional hydrogels were constructed by the interpenetrated quaternized chitosan chain segments and polyacrylamide network. The catechol groups on DA, QT, and the quaternary ammonium groups in the hydrogel system endow hydrogels with high strength, excellent adhesion, and self-healing ability. The results confirmed the admirable hemocompatibility and remarkable antibacterial activity of the multifunction hydrogels against Staphylococcus aureus and Escherichia coli. Consequently, multifunction hydrogels with satisfactory adhesive and antibacterial activity are appropriate alternative materials in the fields of tissue adhesive and wound dressing applications.

Phytoconstituent-Loaded Nanofibrous Meshes as Wound Dressings: A Concise Review

In the past, wounds were treated with natural materials, but modern wound dressings include functional elements to expedite the process of healing and to improve skin recovery. Due to their exceptional properties, nanofibrous wound dressings are now the most cutting-edge and desirable option. Similar in structure to the skin’s own extracellular matrix (ECM), these dressings can promote tissue regeneration, wound fluid transportation, and air ductility for cellular proliferation and regeneration owing to their nanostructured fibrous meshes or scaffolds. Many academic search engines and databases, such as Google Scholar, PubMed, and Sciencedirect, were used to conduct a comprehensive evaluation of the literature for the purposes of this investigation. Using the term “nanofibrous meshes” as a keyword, this paper focuses on the importance of phytoconstituents. This review article summarizes the most recent developments and conclusions from studies on bioactive nanofibrous wound dressings infused with medicinal plants. Several wound-healing methods, wound-dressing materials, and wound-healing components derived from medicinal plants were also discussed.

Controlled release of curcumin from gelatin hydrogels by the molecular-weight modulation of an oxidized dextran cross-linker

Controlled drug delivery could minimize side effects while maintaining a high local dose. Herein, a hydrogel carrier was prepared by forming dynamic imine bonds between gelatin and oxidized dextran (ODex) of different molecular weights (Mw = 10, 70, and 150 kDa). The morphology, thermal stability, rheology, mechanical properties, and swelling properties of the hydrogels and the controlled release of curcumin were characterized. When dextran with a higher Mw was used, the ODex contained more aldehyde groups, which led to a higher degree of cross-linking, considerably shorter gel time, decreased hydrogel porosity, and well-controlled release of curcumin. In addition, the cross-linked hydrogels exhibited not only high thermal stability but also excellent mechanical properties. However, because the matrix was hydrophilic, the swelling properties of the hydrogels were not significantly affected by the Mw of ODex. These observations suggest an approach for designing nutrient delivery carriers with improved controlled release.

Bacterial Cellulose-Carboxymethylcellulose Composite Loaded with Turmeric Extract for Antimicrobial Wound Dressing Applications

Bacterial cellulose (BC) is a biopolymer whose properties have been intensively studied, especially for biomedical applications. Since BC has no antimicrobial activity, it is necessary to use bioactive substances for developing wound healing applications. Another drawback of BC is the loss if its water retention capacity after dehydration. In order to overcome these problems, carboxymethyl cellulose (CMC) and turmeric extract (TE) were selected for the preparation of BC composites. Citric acid (CA) was used as the crosslinking agent. These composites were tested as potential antimicrobial wound dressing materials. TE-loaded BC-CMC composites were characterized in terms of their morphology, crystallinity, and thermal behavior. Swelling tests and curcumin-release kinetic analysis were also performed. All the composites tested had high swelling degrees, which is an advantage for the exudate adsorption from chronic wounds. The antibacterial potential of such composites was tested against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Candida albicans (C. albicans). The in vitro cytotoxicity toward L929 fibroblast cells was studied as well. The obtained results allow us to recommend these composites as good candidates for wound dressing applications.