DEVELOPMENT OF FUNCTIONAL HYBRID SCAFFOLDS FOR WOUND HEALING APPLICATIONS

The effect of nanoceria on the alginate-gum arabic crosslinking mechanism and in vitro behavior as a wound dressing

Medical practice has proven that chronic wounds can be treated successfully if the dressing is chosen according to the healing phase of the wound. Correct intervention from the hemostasis and inflammatory phase can prevent oxidative stress and ensure optimal conditions for healing. It is important to design a new wound dressing that does not cause additional injury, has an antioxidant effect, removes dead cells, and promotes wound healing. Considering that the traditional dressings are not moisture-retentive, we proposed an alginate-gum arabic polymeric matrix enhanced with cerium oxide nanoparticles. The cryogels were prepared by cross-linking polysaccharides and cerium oxide nanoparticles via calcium cations to form a sponge-like structure. The blend of micro- and macro-pores provides a suitable environment for nutrient distribution and keeps an adequate moisture level, mimicking the functions of the native cellular matrix. The release of cerium oxide nanoparticles occurs gradually, at the same time as the degradation of the biopolymer, promoting the attachment and viability of keratinocytes and fibroblast cells. It was found that stimulating epithelial regeneration is improved through the antioxidant effect and the adsorption capacity of hemoglobin. The results also indicate good in vitro biocompatibility and recommend them as promising dressings for skin wound treatments.

Trends in protein derived materials for wound care applications

Natural resource based polymers, especially those derived from proteins, have attracted significant attention for their potential utilization in advanced wound care applications. Protein based wound care materials provide superior biocompatibility, biodegradability, and other functionalities compared to conventional dressings. The effectiveness of various fabrication techniques, such as electrospinning, phase separation, self-assembly, and ball milling, is examined in the context of developing protein-based materials for wound healing. These methods produce a wide range of forms, including hydrogels, scaffolds, sponges, films, and bioinspired nanomaterials, each designed for specific types of wounds and different stages of healing. This review presents a comprehensive analysis of recent research that investigates the transformation of proteins into materials for wound healing applications. Our focus is on essential proteins, such as keratin, collagen, gelatin, silk, zein, and albumin, and we emphasize their distinct traits and roles in wound care management. Protein-based wound care materials show promising potential in biomedical engineering, offering improved healing capabilities and reduced risks of infection. It is crucial to explore the potential use of these materials in clinical settings while also addressing the challenges that may arise from their commercialization in the future.

One-pot synthesis of polysaccharide/gelatin amorphous hydrogels impregnated with a bioflavonoid derived from Elaeis guineensis leaf: wound healing and drug release properties

BACKGROUND

Amorphous hydrogel is a strategic wound healing dressings that comprised of water, polymers and excipients with no shape. The dense cross-linked network of polymer is interspersed by the immobilized water component could rehydrate and promote healing in wound tissue.

OBJECTIVE

In this work, various polysaccharide/gelatin amorphous hydrogels with the impregnation of oil palm leaf derived total flavonoid enriched extract (OPL-TFEE) were fabricated via one-pot synthesis method to provide multiple crosslinking networks.

METHOD

The bioflavonoids (OPL-TFEE) were derived from Elaeis guineensis leaf using an integrated green extraction and enrichment process. Amorphous hydrogels with good wound healing properties were developed by incorporating 0.3% antioxidant agent into the hybrid polymeric gelling system.

RESULT

The formulations appeared as a semi-solid dark yellow translucent hydrogel with good spreading and consistency characteristics and satisfying aesthetic properties. The FTIR analysis indicated that the bioflavonoid was compatible with the matrix, and the hydrogels showed porous morphological structures when observed under SEM. Furthermore, the hydrogels possessed shear thinning, pseudoplastic, and elastic properties. Bioflavonoids-impregnated polysaccharide/gelatin hydrogel release 95-98% bioflavonoids within 24 h, while the drug release profile followed the Korsmeyer-Peppas kinetic model. The hydrogels showed antioxidant and wound healing properties with no sign of cytotoxicity.

CONCLUSION

Overall, the results revealed bioflavonoid-loaded hydrogels exhibited good physicochemical and biological properties, thus could serve as new innovative formulation in the sustainable advancement of wound care product for promoting wound healing.

An in situ forming cartilage matrix mimetic hydrogel scavenges ROS and ameliorates osteoarthritis after superficial cartilage injury

Superficial cartilage defects represent the most prevalent type of cartilage injury encountered in clinical settings, posing significant treatment challenges. Here, we fabricated a cartilage extracellular matrix mimic hydrogel (GHC, consisting of Gelatin, Hyaluronic acid, and Chondroitin sulfate) to avoid the exacerbation of cartilage deterioration, which is often driven by the accumulation of reactive oxygen species (ROS) and a pro-inflammatory microenvironment. The GHC hydrogel exhibited multifunctional properties, including in situ formation, tissue adhesiveness, anti-ROS capabilities, and the promotion of chondrogenesis. The enhancement of tissue adhesion was achieved by chemically modifying hyaluronic acid and chondroitin sulfate with o-nitrobenzene, enabling a covalent connection to the cartilage surface upon light irradiation. In vitro characterization revealed that GHC hydrogel facilitated chondrocyte adhesion, migration, and differentiation into cartilage. Additionally, GHC hydrogels demonstrated the ability to scavenge ROS in vitro and inhibit the production of inflammatory factors by chondrocytes. In the animal model of superficial cartilage injury, the hydrogel effectively promoted cartilage ECM regeneration and facilitated the interface integration between the host tissue and the material. These findings suggest that the multifunctional GHC hydrogels hold considerable promise as a strategy for cartilage defect repair. STATEMENT OF SIGNIFICANCE: Superficial cartilage defects represent the most prevalent type of cartilage injury encountered in the clinic. Previous cartilage tissue engineering materials are only suitable for full-thickness cartilage defects or osteochondral defects. Here, we developed a multifunctional GHC hydrogel composed of gelatin, hyaluronic acid, and chondroitin sulfate, which are natural cartilage extracellular matrix components. The drug-free and cell-free hydrogel not only avoids immune rejection and drug toxicity, but also shows good mechanical properties and biocompatibility. More importantly, the GHC hydrogel could adhere tightly to the superficial cartilage defects and promote cartilage regeneration while protecting against oxidation. This natural ingredients and multifunctional hydrogel is a potential material for repairing superficial cartilage defects.

Eggshell membrane and green seaweed (Ulva lactuca) micronized powders for in vivo diabetic wound healing in albino rats: a comparative study

BACKGROUND

Nonhealing diabetic wounds are a serious complication associated with extremely lethargic wound closure and a high risk of infection, leading to amputation or limb loss, as well as substantial health care costs and a poor quality of life for the patient. The effects of either eggshell membrane (ESM) and green seaweed (Ulva lactuca) extracts alone or in combination were evaluated for in vivo skin wound healing in a rat model of induced diabetes.

METHODS

Micronized powders of waste hen ESM, Ulva lactuca, and their 1:1 mixture were prepared using regular procedures. The mechanical, electrical, and surface morphology characteristics of powders were examined using direct compression, LCR-impedancemetry, and scanning electron microscopy. The effect of ESM, Ulva lactuca, and their mixture as compared to standard Dermazin treatments were evaluated on wounds inflicted on male Wistar Albino rats with induced diabetes. Quantitative wound healing rates at baseline and at 3, 7, 14, and 21 days of treatments among all rat groups were conducted using ANOVA. Qualitative histological analysis of epidermal re-epithelization, keratinocytes, basement membrane, infiltrating lymphocytes, collagen fibrines, and blood vessels at day 21 were performed using Image J processing program.

RESULTS

Compressive strength measurements of tablets showed a Young's modulus of 44.14 and 27.17 MPa for the ESM and ESM + Ulva lactuca mixture, respectively. Moreover, both samples exhibited relatively low relative permittivity values of 6.62 and 6.95 at 1 MHz, respectively, due to the porous surface morphology of ESM shown by scanning electron microscopy. On day 21, rats treated with ESM had a complete diabetic wound closure, hair regrowth, and a healing rate of 99.49%, compared to 96.79% for Dermazin, 87.05% for Ulva lactuca, 90.23% for the mixture, and only 36.44% for the negative controls. A well-formed basement membrane, well-differentiated epithelial cells, and regular thick keratinocytes lining the surface of the epidermal cells accompanied wound healing in rats treated with ESM, which was significantly better than in control rats.

CONCLUSION

Ground hen ESM powder, a low-cost effective biomaterial, is better than Ulva lactuca or their mixture for preventing tissue damage and promoting diabetic wound healing, in addition to various biomedical applications.

Evaluation of cytocompatibility and cell proliferation of electrospun chitosan/polyvinyl alcohol/montmorillonite clay scaffold with l929 cell lines in skin regeneration activity and in silico molecular docking studies

The present investigation describes the development of a novel Chitosan/Polyvinyl Alcohol/Montmorillonite Clay (CS/PVA/MMT) scaffold by adopting an electrospinning method, and their biocompatibility was evaluated in vitro with L929 fibroblast cell line to ascertain its use in wound healing applications. The fabricated scaffold was characterized using analytical techniques. FT-IR measurement exhibited the existence of relevant functional groups and XRD implies scaffolds' amorphous nature. The scaffold's morphology and pore diameter were assessed using TEM and SEM. The pore diameter of the as-prepared scaffold was approximately 125 nm. The antimicrobial assay of the scaffold was evaluated against selected pathogens which demonstrated higher antimicrobial efficacy. The scavenging activity tested using the DPPH assay showed remarkable scavenging capability. The wound healing properties were tested through the Cytotoxicity assay conducted on the L929 assay which proved the scaffold to be a suitable material for cell proliferation. Also, a Molecular docking investigation was carried out for CS/PVA/MMT ligand using human neutrophil elastase (HNE) 1H1B protein as a receptor in the CB-Dock server. Studies conducted in silico revealed strong interaction and high binding energy ratings of CS/PVA/MMT ligand with key residues of human neutrophil elastase (HNE) 1H1B proteins that help in tissue regeneration activity.

Effective wound healing on diabetic mice by adhesive antibacterial GNPs-lysine composited hydrogel

Current trends in wound care research focus on creating dressings for diverse wound types, aiming to effectively control the wound healing process. We proposed a wound dressing composed of oxidized hyaluronic acid and amine gelatin with embedded lysine-modified gelatin nanoparticles (HGel-GNPs-lysine). This dressing improves mechanical properties and reduces degradation rates. The storage modulus for HGel-GNPs-lysine was 3,800 Pa, exceeding that of HGel (1,750 Pa). The positively charged surface of GNPs-lysine effectively eliminated Escherichia coli and Staphylococcus aureus. In a diabetic mice model (C57BL/6), HGel-GNPs-lysine immobilized with basic-fibroblast growth factor promoted granulation tissue thickness and collagen density. Gene expression analysis indicated that HGel-GNPs-lysine reduced inflammation and enhanced angiogenesis. This study highlights that HGel-GNPs-lysine could offer alternative treatment strategies for regulating the inflammatory response at the injury site in wound dressing applications.

Crosslinked Collagen-Hyaluronic Acid Scaffold Enhances Interleukin-10 Under Co-Culture of Macrophages And Adipose-Derived Stem Cells

The skin, the human body's largest organ, possesses a protective barrier that renders it susceptible to various injuries, including burns. Following burn trauma, the inflammatory process triggers both innate and adaptive immune responses, leading to the polarization of macrophages into two distinct phenotypes: the pro-inflammatory M1 and the anti-inflammatory M2. This dual response sets the stage for wound healing and subsequent tissue regeneration. Contributing to this transition from M1 to M2 polarization are human adipose-derived stem cells (ASCs), which employ paracrine signaling and inflammation suppression to enhance the remodeling phase. ASCs, when combined with biocompatible polymers, can be integrated into functional scaffolds. This study introduces an 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide-crosslinked (EDC-crosslinked) collagen-hyaluronic acid (Col-HA) scaffold assembled with ASCs, designed as a natural biomaterial device to modulate macrophage behavior in vitro under co-culture conditions. This innovation aims to improve wound healing processes. The EDC-crosslinked Col-HA scaffold favored the release of anti-inflammatory cytokines by ASCs, which indicated the M2 prevalence. In tissue engineering, a critical objective lies in the development of functional biomaterials capable of guiding specific tissue responses, notably the control of inflammatory processes. Thus, this research not only presents original findings but also points toward a promising avenue within regenerative medicine.

3D-Printed Collagen-Nanocellulose Hybrid Bioscaffolds with Tailored Properties for Tissue Engineering Applications

Hybrid collagen (Coll) bioscaffolds have emerged as a promising solution for tissue engineering (TE) and regenerative medicine. These innovative bioscaffolds combine the beneficial properties of Coll, an important structural protein of the extracellular matrix, with various other biomaterials to create platforms for long-term cell growth and tissue formation. The integration or cross-linking of Coll with other biomaterials increases mechanical strength and stability and introduces tailored biochemical and physical factors that mimic the natural tissue microenvironment. This work reports on the fabrication of chemically cross-linked hybrid bioscaffolds with enhanced properties from the combination of Coll, nanofibrillated cellulose (NFC), carboxymethylcellulose (CMC), and citric acid (CA). The bioscaffolds were prepared by 3D printing ink containing Coll-NFC-CMC-CA followed by freeze-drying, dehydrothermal treatment, and neutralization. Cross-linking through the formation of ester bonds between the polymers and CA in the bioscaffolds was achieved by exposing the bioscaffolds to elevated temperatures in the dry state. The morphology, pores/porosity, chemical composition, structure, thermal behavior, swelling, degradation, and mechanical properties of the bioscaffolds in the dry and wet states were investigated as a function of Coll concentration. The bioscaffolds showed no cytotoxicity to MG-63 human bone osteosarcoma cells as tested by different assays measuring different end points. Overall, the presented hybrid Coll bioscaffolds offer a unique combination of biocompatibility, stability, and structural support, making them valuable tools for TE.

3D Matrices for Enhanced Encapsulation and Controlled Release of Anti-Inflammatory Bioactive Compounds in Wound Healing

Current trends in the development of wound dressings are oriented towards the use of biopolymer-based materials, due to their unique properties such as non-toxicity, hydrophilicity, biocompatibility and biodegradability, properties that have advantageous therapeutic characteristics. In this regard, the present study aims to develop hydrogels based on cellulose and dextran (CD) and to reveal their anti-inflammatory performance. This purpose is achieved by incorporating plant bioactive polyphenols (PFs) in CD hydrogels. The assessments include establishing the structural characteristics using attenuated total reflection Fourier transformed infrared (ATR-FTIR) spectroscopy, the morphology by scanning electron microscopy (SEM), the swelling degree of hydrogels, the PFs incorporation/release kinetics and the hydrogels' cytotoxicity, together with evaluation of the anti-inflammatory properties of PFs-loaded hydrogels. The results show that the presence of dextran has a positive impact on the hydrogel's structure by decreasing the pore size at the same time as increasing the uniformity and interconnectivity of the pores. In addition, there is an increased degree of swelling and of the encapsulation capacity of PFs, with the increase of the dextran content in hydrogels. The kinetics of PFs released by hydrogels was studied according to the Korsmeyer-Peppas model, and it was observed that the transport mechanisms depend on hydrogels' composition and morphology. Furthermore, CD hydrogels have been shown to promote cell proliferation without cytotoxicity, by successfully culturing fibroblasts and endothelial cells on CD hydrogels (over 80% viability). The anti-inflammatory tests performed in the presence of lipopolysaccharides demonstrate the anti-inflammatory properties of the PFs-loaded hydrogels. All these results provide conclusive evidence on the acceleration of wound healing by inhibiting the inflammation process and support the use of these hydrogels encapsulated with PFs in wound healing applications.

Titanium Dioxide/Chromium Oxide/Graphene Oxide Doped into Cellulose Acetate for Medical Applications

Wound dressings have been designed based on cellulose acetate encapsulated with different concentrations of chromium oxide (Cr₂O₃) and titanium oxide (TiO₂) with/without graphene oxide (GO). This study comprises the structural, morphological, optical, thermal, and biological behavior of chromium oxide/titanium dioxide/graphene oxide-integrated cellulose acetate (CA) films. The CA-based film bond formation was introduced by functional group analysis via Fourier transform infrared (FTIR) spectroscopy. The fabricated Cr₂O₃/TiO₂/GO@CA film SEM micrographs demonstrate transition metal oxides Cr₂O₃ and TiO₂ on a nano-scale. The TiO₂@CA shows the lowest contact angle with 30°. Optically, the refractive index increases from 1.76 for CA to 2.14 for the TiO₂@CA film. Moreover, normal lung cells (A138) growth examination in a function of Cr₂O₃/TiO₂/GO@CA film concentration is conducted, introducing 93.46% with the usage of 4.9 µg/mL. The resulting data showed a promising wound-healing behavior of the CA-based films.

Chitosan, chondroitin sulfate, and hyaluronic acid based in-situ forming scaffold for efficient cell grafting

Current cell grafting techniques are majorly dependent on seeding cells on a pre-formed scaffold. However, cells grow in a 2-dimensional (2D) space in such constructs, not mimicking the tissue's 3-dimensional (3D) architecture. The present study evaluated a unique poly-electrolyte complexation (PEC) based strategy for the 3D engraftment of cells in a porous polymeric scaffold. The scaffold was synthesized using a positively charged polysaccharide chitosan (CH) and negatively charged glycosaminoglycans chondroitin sulfate (CS) and hyaluronic acid (HA). Two different scaffolds were synthesized, one using CH and CS [CH-CS] and another using CH and CS + HA [CH-(CS-HA)]. The physicochemical characterization of both the PECs confirmed electrostatic interactions, leading to a porous and viscoelastic PEC formation. Fibroblast cells were grafted and seeded in both scaffolds to evaluate the effect of different scaffold compositions and the difference between seeded and grafted cells. Imaging studies confirmed that grafting of the fibroblast cells supports cellular proliferation. The qPCR studies demonstrated increased expression of functional markers TGF-β, α-SMA, collagen-I, and fibronectin in the CH-(CS-HA) grafted cells. In summary, it was demonstrated that an in-situ forming PEC of CH, CS, and HA had good physicochemical properties for cell grafting and supported grafted cells with improved function.

Cell Secretome Strategies for Controlled Drug Delivery and Wound-Healing Applications

There is significant interest in using stem cells in the management of cutaneous wounds. However, potential safety, efficacy, and cost problems associated with whole-cell transplantation hinder their clinical application. Secretome, a collective of mesenchymal stem-cell-stored paracrine factors, and immunomodulatory cytokines offer therapeutic potential as a cell-free therapy for the treatment of cutaneous wounds. This review explores the possibility of secretome as a treatment for cutaneous wounds and tissue regeneration. The review mainly focuses on in vitro and in vivo investigations that use biomaterials and secretome together to treat wounds, extend secretome retention, and control release to preserve their biological function. The approaches employed for the fabrication of biomaterials with condition media or extracellular vesicles are discussed to identify their future clinical application in wound treatment.

A photo-triggering double cross-linked adhesive, antibacterial, and biocompatible hydrogel for wound healing

Full-thickness wounds, lacking the epidermis and entire dermis and extending into subcutaneous fat, represent a common treatment challenge. Due to the loss of adnexal structures as a source of keratinocytes, full-thickness wounds healing can only be achieved by re-epithelialization from the wound edge and contraction. Here, we developed a hydrogel composed of chitosan methacrylate (CSMA) and o-nitrosobenzaldehyde-modified gelatin (GelNB) for promoting full-thickness wound healing. The CSMA/GelNB (CM/GN) hydrogels exhibited superior mechanical and adhesive properties than that of pure CSMA hydrogel. In vivo experiments confirmed that CM/GN could promote wound healing by generating more hair follicles and mutual blood vessels, high fibroblasts density, and thicker granulation tissue thickness. In addition, reduced secretions of tumor necrosis factor-α (TNF-α) and enhanced secretions of vascular endothelial growth factor (VEGF) could be observed in regenerated tissues after CM/GN treatment. These results suggested that CM/GN hydrogels could be promising candidates to promote wound healing.

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The CM/GN hydrogels exhibited tissue adhesive properties

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CM/GN hydrogel facilitated the proliferation of bone marrow stem cells

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CM/GN hydrogel efficiently promote full-thickness wound healing

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More hair follicles and mutual blood vessels were generated during wound healing