Quercetin impregnated chitosan–fibrin composite scaffolds as potential wound dressing materials — Fabrication, characterization and in vivo analysis

Exploring bio-nanomaterials as antibiotic allies to combat antimicrobial resistance

Antimicrobial resistance (AMR) poses an emergent threat to global health due to antibiotic abuse, overuse and misuse, necessitating urgent innovative and sustainable solutions. The utilization of bio-nanomaterials as antibiotic allies is a green, economic, sustainable and renewable strategy to combat this pressing issue. These biomaterials involve green precursors (e.g. biowaste, plant extracts, essential oil, microbes, and agricultural residue) and techniques for their fabrication, which reduce their cyto/environmental toxicity and exhibit economic manufacturing, enabling a waste-to-wealth circular economy module. Their nanoscale dimensions with augmented biocompatibility characterize bio-nanomaterials and offer distinctive advantages in addressing AMR. Their ability to target pathogens, such as bacteria and viruses, at the molecular level, coupled with their diverse functionalities and bio-functionality doping from natural precursors, allows for a multifaceted approach to combat resistance. Furthermore, bio-nanomaterials can be tailored to enhance the efficacy of existing antimicrobial agents or deliver novel therapies, presenting a versatile platform for innovation. Their use in combination with traditional antibiotics can mitigate resistance mechanisms, prolong the effectiveness of existing treatments, and reduce side effects. This review aims to shed light on the potential of bio-nanomaterials in countering AMR, related mechanisms, and their applications in various domains. These roles encompass co-therapy, nanoencapsulation, and antimicrobial stewardship, each offering a distinct avenue for overcoming AMR. Besides, it addresses the challenges associated with bio-nanomaterials, emphasizing the importance of regulatory considerations. These green biomaterials are the near future of One Health Care, which will have economic, non-polluting, non-toxic, anti-resistant, biocompatible, degradable, and repurposable avenues, contributing to sustainable development goals.

Antiangiogenic Potential of Troxerutin and Chitosan Loaded Troxerutin on Chorioallantoic Membrane Model

Angiogenesis is crucial to the development of cancer because it allows the transport of oxygen, nutrients, and growth factors as well as the spread of tumors to distant organs. Inhibitors of angiogenesis prevent the formation of blood vessels that allow tumor cells to shrink, rather than promote tumor growth. Chitosan acts as a carrier for many drugs, since the compound has various properties such as biodegradable, less toxicity, more stable, simple, easy to prepare, and biocompatible. The aim of the current study was to evaluate the efficacy of chitosan nanoparticles encapsulated with troxerutin (Chi-Trox NPs) against angiogenesis and cancer in ova chick chorioallantoic membrane (CAM) model. Chi-Trox NPs were synthesized using a nanoprecipitation method and were characterized by various analyses. 24 hours' fertilized eggs (6 eggs/group) were treated with native Trox and Chi-Trox NPs for 5 days. The antiangiogenic activity was evaluated by morphometric, histopathological, immunohistochemical (CD104 and vimentin), and mRNA expression of MMP and FGF2 using RT-PCR. The anticancer activity was evaluated by histopathological, immunohistochmical (CD44), and mRNA expression of FGF2 and MMP. The synthesized chitosan NPs were successfully encapsulated with troxerutin, and the loading efficiency of chitosan NPs was found to be 86.4 ± 0.12% and 13.2 ± 0.16% respectively. Morphometric analysis of Chi-Trox NPs showed a considerable decrease in the number of blood vessels compared with control and native Trox. The histopathological observation of CAM confirmed that Chi-Trox NPs induce a significant reduction in inflammatory cells and the thickness of blood capillaries compared to control and native Trox. The immunohistochemical evaluation of CAM revealed Chi-Trox decreased CD104, vimentin and CD44 protein levels were compared with control and native Trox. Furthermore, the mRNA expression levels of FGF2 and MMP were significantly downregulated compared to their native forms. From the obtained results, Chi-Trox NPs possess significant inhibition of angiogenesis and can be used as therapeutic agents for cancer in the future.

Sustainable Approach of Functional Biomaterials-Tissue Engineering for Skin Burn Treatment: A Comprehensive Review

Burns are a widespread global public health traumatic injury affecting many people worldwide. Non-fatal burn injuries are a leading cause of morbidity, resulting in prolonged hospitalization, disfigurement, and disability, often with resulting stigma and rejection. The treatment of burns is aimed at controlling pain, removing dead tissue, preventing infection, reducing scarring risk, and tissue regeneration. Traditional burn wound treatment methods include the use of synthetic materials such as petroleum-based ointments and plastic films. However, these materials can be associated with negative environmental impacts and may not be biocompatible with the human body. Tissue engineering has emerged as a promising approach to treating burns, and sustainable biomaterials have been developed as an alternative treatment option. Green biomaterials such as collagen, cellulose, chitosan, and others are biocompatible, biodegradable, environment-friendly, and cost-effective, which reduces the environmental impact of their production and disposal. They are effective in promoting wound healing and reducing the risk of infection and have other benefits such as reducing inflammation and promoting angiogenesis. This comprehensive review focuses on the use of multifunctional green biomaterials that have the potential to revolutionize the way we treat skin burns, promoting faster and more efficient healing while minimizing scarring and tissue damage.

Proline conjugated chitosan as wound healing material: In vitro studies on the influence of the scaffold on collagen production and wound healing

The present study reports the development of L-proline conjugated chitosan scaffold for wound healing application. Proline plays a beneficial role in collagen synthesis, and as a biochemical, it has the potential to modulate wound healing. In this regard, amino acid L-proline was conjugated onto chitosan, and the scaffolds were synthesised. FTIR and NMR analysis confirmed amino acid conjugation. The prepared scaffold was characterized by studies such as swelling, dissolution, tensile strength, porosity, water-vapor transmission rate and in-vitro healing properties. Cell viability assay showed that the scaffold has no cytotoxicity against the L929 and HaCaT cells. The in-vitro wound healing potential of the scaffold by scratch wound assay on the L929 cell line showed 53.35 ± 2.3 %, 72.96 ± 2.2 %, and 50.89 ± 0.3 % wound closure for CS-P 200, CS-P 400 and CS-P 600, respectively when compared to native CS scaffold (38.86 ± 1.6 %). A similar observation was found with HaCaT cells too. The studies showed that the modified scaffold promotes collagen deposition from fibroblast cells. These findings suggest that scaffold cues remodel the wound microenvironment for a better wound-healing state, and the L-proline conjugated scaffold may have considerable potential as a wound dressing to improve wound healing.

Flavonoids and their therapeutic applications in skin diseases

Flavonoids are a class of plant polyphenols found in a variety of fruits, vegetables, teas, and flowers. These compounds are present in many common dietary sources, such as green tea, wine, pomegranates, and turmeric, and possess a broad spectrum of biological activity due to their unique chemical structure. Flavonoids exhibit antioxidant, anti-inflammatory, antiviral, and anticarcinogenic properties that have been widely studied as potential therapeutics for diseases ranging from Alzheimer's disease to liver disease. There is currently significant research into therapeutic benefits of flavonoids in various skin conditions as these compounds have been shown to absorb ultraviolet radiation and modulate cancer and inflammation signaling pathways. This review discusses the current research in the application of flavonoids in skin diseases (e.g., prevention of premature photoaging, prevention and treatment of skin cancer, and promotion of skin wound healing) and their proposed mechanisms to provide a basis for future basic and translational research of flavonoids as potential drugs in the prevention and treatment of skin disorders.

Flavonoids and their therapeutic applications in skin diseases

Flavonoids are a class of plant polyphenols found in a variety of fruits, vegetables, teas, and flowers. These compounds are present in many common dietary sources, such as green tea, wine, pomegranates, and turmeric, and possess a broad spectrum of biological activity due to their unique chemical structure. Flavonoids exhibit antioxidant, anti-inflammatory, antiviral, and anticarcinogenic properties that have been widely studied as potential therapeutics for diseases ranging from Alzheimer's disease to liver disease. There is currently significant research into therapeutic benefits of flavonoids in various skin conditions as these compounds have been shown to absorb ultraviolet radiation and modulate cancer and inflammation signaling pathways. This review discusses the current research in the application of flavonoids in skin diseases (e.g., prevention of premature photoaging, prevention and treatment of skin cancer, and promotion of skin wound healing) and their proposed mechanisms to provide a basis for future basic and translational research of flavonoids as potential drugs in the prevention and treatment of skin disorders.

Electrically Triggered Quercetin Release from Polycaprolactone/Bismuth Ferrite Microfibrous Scaffold for Skeletal Muscle Tissue

Skeletal muscle tissue engineering presents a promising avenue to address the limitations pertaining to the regenerative potential of stem cells in case of injury or damage. The objective of this research was to evaluate the effects of utilizing novel microfibrous scaffolds, containing the compound quercetin (Q), on skeletal muscle regeneration. Morphological test results showed us that the combination of bismuth ferrite (BFO), polycaprolactone (PCL), and Q were bonded and well-ordered with each other, and a uniform microfibrous structure was obtained. Antimicrobial susceptibility testing of PCL/BFO/Q was conducted, and microbial reduction was found to be over 90% in the highest concentration of Q-loaded microfibrous scaffolds with the most inhibitory effect on S. aureus strains. Further, biocompatibility was investigated by performing MTT testing, fluorescence testing, and SEM imaging on mesenchymal stem cells (MSCs) to determine whether they could act as suitable microfibrous scaffolds for skeletal muscle tissue engineering. Incremental changes in the concentration of Q led to increased strength and strain, allowing muscles to withstand stretching during the healing process. In addition, electrically conductive microfibrous scaffolds enhanced the drug release capability by revealing that Q can be released significantly more quickly by applying the appropriate electric field, compared with conventional drug-release techniques. These findings suggest a possible use for PCL/BFO/Q microfibrous scaffolds in skeletal muscle regeneration by demonstrating that the combined action of both guidance biomaterials was more successful than Q itself acting alone.

Chitosan-Polyphenol Conjugates for Human Health

Human health deteriorates due to the generation and accumulation of free radicals that induce oxidative stress, damaging proteins, lipids, and nucleic acids; this has become the leading cause of many deadly diseases such as cardiovascular, cancer, neurodegenerative, diabetes, and inflammation. Naturally occurring polyphenols have tremendous therapeutic potential, but their short biological half-life and rapid metabolism limit their use. Recent advancements in polymer science have provided numerous varieties of natural and synthetic polymers. Chitosan is widely used due to its biomimetic properties which include biodegradability, biocompatibility, inherent antimicrobial activity, and antioxidant properties. However, due to low solubility in water and the non-availability of the H-atom donor, the practical use of chitosan as an antioxidant is limited. Therefore, chitosan has been conjugated with polyphenols to overcome the limitations of both chitosan and polyphenol, along with increasing the potential synergistic effects of their combination for therapeutic applications. Though many methods have been evolved to conjugate chitosan with polyphenol through activated ester-modification, enzyme-mediated, and free radical induced are the most widely used strategies. The therapeutic efficiency of chitosan-polyphenol conjugates has been investigated for various disease treatments caused by ROS that have shown favorable outcomes and tremendous results. Hence, the present review focuses on the recent advancement of different strategies of chitosan-polyphenol conjugate formation with their advantages and limitations. Furthermore, the therapeutic applicability of the combinatorial efficiency of chitosan-based conjugates formed using Gallic Acid, Curcumin, Catechin, and Quercetin in human health has been described in detail.

The potential of functionalized dressing releasing flavonoids facilitates scar-free healing

Scars are pathological marks left after an injury heals that inflict physical and psychological harm, especially the great threat to development and aesthetics posed by oral and maxillofacial scars. The differential expression of genes such as transforming growth factor-β, local adherent plaque kinase, and yes-related transcriptional regulators at infancy or the oral mucosa is thought to be the reason of scarless regenerative capacity after tissue defects. Currently, tissue engineering products for defect repair frequently overlook the management of postoperative scars, and inhibitors of important genes alone have negative consequences for the organism. Natural flavonoids have hemostatic, anti-inflammatory, antioxidant, and antibacterial properties, which promote wound healing and have anti-scar properties by interfering with the transmission of key signaling pathways involved in scar formation. The combination of flavonoid-rich drug dressings provides a platform for clinical translation of compounds that aid in drug disintegration, prolonged release, and targeted delivery. Therefore, we present a review of the mechanisms and effects of flavonoids in promoting scar-free regeneration and the application of flavonoid-laden dressings.

Advances in Fibrin-Based Materials in Wound Repair: A Review

The first bioprocess that occurs in response to wounding is the deterrence of local hemorrhage. This is accomplished by platelet aggregation and initiation of the hemostasis cascade. The resulting blood clot immediately enables the cessation of bleeding and then functions as a provisional matrix for wound healing, which begins a few days after injury. Here, fibrinogen and fibrin fibers are the key players, because they literally serve as scaffolds for tissue regeneration and promote the migration of cells, as well as the ingrowth of tissues. Fibrin is also an important modulator of healing and a host defense system against microbes that effectively maintains incoming leukocytes and acts as reservoir for growth factors. This review presents recent advances in the understanding and applications of fibrin and fibrin-fiber-incorporated biomedical materials applied to wound healing and subsequent tissue repair. It also discusses how fibrin-based materials function through several wound healing stages including physical barrier formation, the entrapment of bacteria, drug and cell delivery, and eventual degradation. Pure fibrin is not mechanically strong and stable enough to act as a singular wound repair material. To alleviate this problem, this paper will demonstrate recent advances in the modification of fibrin with next-generation materials exhibiting enhanced stability and medical efficacy, along with a detailed look at the mechanical properties of fibrin and fibrin-laden materials. Specifically, fibrin-based nanocomposites and their role in wound repair, sustained drug release, cell delivery to wound sites, skin reconstruction, and biomedical applications of drug-loaded fibrin-based materials will be demonstrated and discussed.

Usefulness of customized titanium plates for midface contouring surgery

INTRODUCTION AND IMPORTANCE

In our department, we have been performing bone reconstructions on a case-by-case basis using vascularized free tissue transfers and custom-made artificial bones (HA). While these procedures have specific advantages, they are also limited in terms of the invasiveness as well as the stability and strength of implants. In the present study, we describe the use of a CTP to achieve minimally invasive midface plastic surgery with the superior moldability of a 3D structure and reliable stability compared to the use of autologous tissue.

CASE PRESENTATION

A total of three patients were included in the study. The patients (all female, ages: 66, 18, and 35 years) had bone malformation or hemifacial microsomia following surgery for maxillary cancer or multiple facial fractures. Based on DICOM data from preoperative CT, 3D models were created on a computer using CAD/CAM techniques. The models were compared in simulations to determine the optimal structure. These 3D models were used in additive manufacturing systems to create custom-made titanium alloy plates for facial reconstruction.

CLINICAL DISCUSSION

Although the amount of soft tissue was insufficient in some cases, all patients were able to maintain the desired morphology without developing any complications such as infections, significant soft tissue atrophy, or implant failure.

CONCLUSION

Our CTP model created by CAD/CAM was effective in contouring surgery of the midface as it had the superior stability and biocompatibility of titanium. Changes to the soft tissue should also be considered in order to further improve the procedure.

Modern Dressings in Prevention and Therapy of Acute and Chronic Radiation Dermatitis—A Literature Review

Radiotherapy is an integral part of modern oncology, applied to more than half of all patients diagnosed with cancer. It can be used alone or in combination with surgery or chemotherapy. However, despite the high precision of radiation delivery, irradiation may affect surrounding healthy tissues leading to the development of toxicity. The most common and clinically significant toxicity of radiotherapy is acute and chronic radiation dermatitis, which could result in desquamation, wounds, nonhealing ulcers, and radionecrosis. Moreover, preoperative radiotherapy impairs wound healing after surgery and may lead to severe wound complications. In this review, we comprehensively discuss available types of dressings used in the management of acute and chronic radiation dermatitis and address their efficacy. The most effective ways of preventing acute radiation dermatitis are film dressings, whereas foam dressings were found effective in its treatment. Data regarding dressings in chronic radiation dermatitis are scarce. This manuscript also contains authors’ consensus.

Fabrication and evaluation of Cs/PVP sponge containing platelet-rich fibrin as a wound healing accelerator: An in vitro and in vivo study

Despite significant advances in surgery and postoperative care, there are still challenges in the treatment of wounds. In the current study, a freeze-dried chitosan (Cs)/polyvinylpyrrolidone (PVP) sponges containing platelet-rich fibrin (PRF at 1, 1.5 and 2% w/v) for wound dressing application is fabricated and fully characterized. Addition of 1% w/v of PRF to Cs/PVP (CS/PVP/1PRF) sample significantly increased the tensile strength (from 0.147 ± 0.005 to 0.242 ± 0.001 MPa), elastic modulus (from 0.414 ± 0.014 to 0.611 ± 0.022 MPa) and strain at break (from 53.4 ± 0.9 to 61.83 ± 1.17%) compared to Cs sample, and was hence selected as the optimal sample. The antibacterial activity of Cs/PVP/1PRF sponge wound dressing against E. coli and S. aureus was confirmed to be effective. Enzyme-linked immunosorbent assays revealed that the release of both VEGF and PDGF-AB from PRF powder, as well as PDGF-AB from Cs/PVP/1PRF sample was time-independent, but the release of VEGF from Cs/PVP/1PRF sample increased significantly with time. According to MTT and CAM assays, the Cs/PVP/1PRF sample significantly increased proliferation and angiogenic potential, respectively. Furthermore, in vivo studies demonstrated a 97.16 ± 1.55% wound closure for Cs/PVP/1PRF group after 14 days.

Wound healing properties of flavonoids: A systematic review highlighting the mechanisms of action

BACKGROUND

Flavonoids are a class of compounds with a wide variety of biological functions, being an important source of new products with pharmaceutical potential, including treatment of skin wounds.

PURPOSE

This review aimed to summarize and evaluate the evidence in the literature in respect of the healing properties of flavonoids on skin wounds in animal models.

STUDY DESIGN

This is a systematic review following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement.

METHODS

This was carried out through a specialized search of four databases: PubMed, Scopus, Web of Science and Embase. The following keyword combinations were used: "flavonoidal" OR "flavonoid" OR "flavonoidic" OR "flavonoids" AND "wound healing" as well as MeSH terms, Emtree terms and free-text words.

RESULTS

Fifty-five (55) articles met the established inclusion and exclusion criteria. Flavonoids presented effects in respect of the inflammatory process, angiogenesis, re-epithelialization and oxidative stress. They were shown to be able to act on macrophages, fibroblasts and endothelial cells by mediating the release and expression of TGF-β1, VEGF, Ang, Tie, Smad 2 and 3, and IL-10. Moreover, they were able to reduce the release of inflammatory cytokines, NFκB, ROS and the M1 phenotype. Flavonoids acted by positively regulating MMPs 2, 8, 9 and 13, and the Ras/Raf/MEK/ERK, PI3K/Akt and NO pathways.

CONCLUSION

Flavonoids are useful tools in the development of therapies to treat skin lesions, and our review provides a scientific basis for future basic and translational research.

Novel chitosan-ulvan hydrogel reinforcement by cellulose nanocrystals with epidermal growth factor for enhanced wound healing: In vitro and in vivo analysis

Several dressing materials can be used efficiently in recent times, both in their natural and synthetic combinations like; microfibers, film, nanofibers, hydrogels, and various drugs. The specific characteristics, such as biocompatibility and providing a favorable environment for wound healing, make many polysaccharides pivotal as wound dressings. Keeping in view the importance of these polysaccharides, we have developed novel chitosan-ulvan hydrogel incorporated by cellulose nanocrystals (CNCs) loading epidermal growth factor (EGF) drug (CS-U-CNC-EGF) by the freeze-dried process. The morphological features of novel hydrogel were perceived by FTIR, XRD, FESEM, and DSC analysis. The incorporation of the nanocrystals content modified the porous microstructure at pore size from 237 ± 59 μm to 53 ± 16 μm, improved mechanical stress curve from 0.57 MPa to 1.2 MPa, thermal and swelling behavior. The novel nanocomposites revealed non-toxic behavior and excellent cell proliferation. Whereas hydrogel showed sustained release of the epidermal growth factor (EGF), thereby enhancing EGF delivery at the wound site for 15 days from a 100% wound contraction treated group. Moreover, the controlled release of EGF from CS-U-CNC-EGF hydrogels showed significantly faster-wound healing efficiency concerning considerably faster granulations tissue formation and collagen deposition. The study's results point to possible future applications of this composite hydrogel in wound healing as a wound dressing material.

Three Polymers from the Sea: Unique Structures, Directional Modifications, and Medical Applications

With the increase of wounds and body damage, the clinical demand for antibacterial, hemostatic, and repairable biomaterials is increasing. Various types of biomedical materials have become research hotspots. Of these, and among materials derived from marine organisms, the research and application of alginate, chitosan, and collagen are the most common. Chitosan is mainly used as a hemostatic material in clinical applications, but due to problems such as the poor mechanical strength of a single component, the general antibacterial ability, and fast degradation speed research into the extraction process and modification mainly focuses on the improvement of the above-mentioned ability. Similarly, the research and modification of sodium alginate, used as a material for hemostasis and the repair of wounds, is mainly focused on the improvement of cell adhesion, hydrophilicity, degradation speed, mechanical properties, etc.; therefore, there are fewer marine biological collagen products. The research mainly focuses on immunogenicity removal and mechanical performance improvement. This article summarizes the source, molecular structure, and characteristics of alginate, chitosan, and collagen from marine organisms; and introduces the biological safety, clinical efficacy, and mechanism of action of these materials, as well as their extraction processes and material properties. Their modification and other issues are also discussed, and their potential clinical applications are examined.

Chitosan/Hyaluronic acid/Alginate and an assorted polymers loaded with honey, plant, and marine compounds for progressive wound healing-Know-how

Biomaterials are being extensively used in regenerative medicine including tissue engineering applications, as these enhance tissue development, repair, and help in the process of angiogenesis. Wound healing is a crucial biological process of regeneration of ruptured tissue after getting injury to the skin and other soft tissue in humans and animals. Besides, the accumulation of microbial biofilms around the wound surface can increase the risk and physically obstruct the wound healing activity, and may even lead to amputation. Hence, in both acute and chronic wounds, prominent biomaterials are required for wound healing along with antimicrobial agents. This review comprehensively addresses the antimicrobial and wound healing effects of chitosan, chitin, cellulose acetate, hyaluronic acid, pullulan, bacterial cellulose, fibrin, alginate, etc. based wound dressing biomaterials fabricated with natural resources such as honey, plant bioactive compounds, and marine-based polymers. Due to their excellent biocompatibility and biodegradability, bioactive compounds derived from honey, plants, and marine resources are commonly used in biomedical and tissue engineering applications. Different types of polymer-based biomaterials including hydrogel, film, scaffold, nanofiber, and sponge dressings fabricated with bioactive agents including honey, curcumin, tannin, quercetin, andrographolide, gelatin, carrageenan, etc., can exhibit significant wound healing process in, diabetic wounds, diabetic ulcers, and burns, and help in cartilage repair along with good biocompatibility and antimicrobial effects. Among the reviewed biomaterials, carbohydrate polymers such as chitosan-based biomaterials are prominent and widely used for wound healing applications followed by hyaluronic acid and alginate-based biomaterials loaded with honey, plant, and marine compounds. This review first provides an overview of the vast natural resources used to formulate different biomaterials for the treatment of antimicrobial, acute, and chronic wound healing processes.

Electrically Triggered Drug Delivery from Novel Electrospun Poly(Lactic Acid)/Graphene Oxide/Quercetin Fibrous Scaffolds for Wound Dressing Applications

The novel controlled and localized delivery of drug molecules to target tissues using an external electric stimulus makes electro-responsive drug delivery systems both feasible and desirable, as well as entailing a reduction in the side effects. Novel micro-scaffold matrices were designed based on poly(lactic acid) (PLA) and graphene oxide (GO) via electrospinning. Quercetin (Q), a natural flavonoid, was loaded into the fiber matrices in order to investigate the potential as a model drug for wound dressing applications. The physico-chemical properties, electrical triggering capacity, antimicrobial assay and biocompatibility were also investigated. The newly fabricated PLA/GO/Q scaffolds showed uniform and smooth surface morphologies, without any beads, and with diameters ranging from 1107 nm (10%PLA/0.1GO/Q) to 1243 nm (10%PLA). The in vitro release tests of Q from the scaffolds showed that Q can be released much faster (up to 8640 times) when an appropriate electric field is applied compared to traditional drug-release approaches. For instance, 10 s of electric stimulation is enough to ensure the full delivery of the loaded Q from the 10%PLA/1%GO/Q microfiber scaffold at both 10 Hz and at 50 Hz. The antimicrobial tests showed the inhibition of bacterial film growth. Certainly, these materials could be loaded with more potent agents for anti-cancer, anti-infection, and anti-osteoporotic therapies. The L929 fibroblast cells cultured on these scaffolds were distributed homogeneously on the scaffolds, and the highest viability value of 82.3% was obtained for the 10%PLA/0.5%GO/Q microfiber scaffold. Moreover, the addition of Q in the PLA/GO matrix stimulated the production of IL-6 at 24 h, which could be linked to an acute inflammatory response in the exposed fibroblast cells, as a potential effect of wound healing. As a general conclusion, these results demonstrate the possibility of developing graphene oxide-based supports for the electrically triggered delivery of biological active agents, with the delivery rate being externally controlled in order to ensure personalized release.

Fabrication and characterization of Chrysin - A plant polyphenol loaded alginate -chitosan composite for wound healing application

The present study explores the therapeutic efficacy of sodium alginate-chitosan scaffolds loaded with Chrysin (ALG-CS-CHY) for dermal wound management. Scaffolds were prepared by the vacuum freeze-drying method. The physiochemical characterization was done through Fourier Transform Infra-Red Spectroscopy (FTIR), which revealed the interactions between the scaffold's functional groups and the drug. Surface Electron microscopy (SEM) showed a porous architecture varying from 200-400 μm. X-ray Diffraction (XRD) showed an ionic interaction between ALG-CS leading to their excellent compatibility. Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) results suggest increased ALG-CS scaffold's thermal stability. In-vitro biodegradation behavior demonstrated controlled degradation with lysozyme. The swelling ratio was highest in the first hour and decreased slowly with time, and the porosity analysis showed a high degree of porosity. The ALG-CS scaffold showed sustained drug availability and minimized re-application, which contributes to effective healing and treatment. The blood compatibility and whole blood clotting ability of the scaffold significantly improved after incorporating the drug. Calcein AM, Propidium iodide, was used for live and dead cell staining, which confirmed that fabricated ALG-CS-CHY scaffolds are biocompatible and facilitate cell growth and cell proliferation. In-vivo and in-vitro observations show that the experimental group treated using the ALG-CS-CHY reduces the period of re-epithelization, accelerated fibroblast cell migration, and contracted wound significantly (p < 0.001) compared to other groups. ALG-CS-CHY scaffolds also increased collagen deposition, hexosamine synthesis, accelerates angiogenesis, and recruiting immune cells at the site of a wound. These results suggest ALG-CS-CHY scaffold serves as an effective dressing for dermal wound management.

Edible Materials in Tissue Regeneration

Edible materials have attracted increasing attention because of their excellent properties including availability, biocompatibility, biological activity, and biodegradability. Natural polysaccharides, phenolic compounds, and proteins are widely used in tissue regeneration. To better characterize their healing effect, this review article describes the applications of edible materials in tissue regeneration including wound healing and bone tissue regeneration. As an introduction to the topic, their sources and main bioactive properties are discussed. Then, the mechanism by which they facilitate wound healing based on their hemostasis, antibacterial, anti-inflammatory, and antioxidant properties is systematically investigated. Moreover, a more comprehensive discussion is presented on the approaches by which edible materials can be used as scaffolds or agents for the provision of the components of natural bones for regulating the level of osteogenesis-related cytokines to enhance bone repair. Finally, the prospects of edible materials for tissue regeneration are discussed.

Improving Fibrin Hydrogels' Mechanical Properties, through Addition of Silica or Chitosan-Silica Materials, for Potential Application as Wound Dressings

Fibrin is a protein-based hydrogel formed during blood coagulation. It can also be produced in vitro from human blood plasma, and it is capable of resisting high deformations. However, after each deformation process, it loses high amounts of water, which subsequently makes it mechanically unstable and, finally, difficult to manipulate. The objective of this work was to overcome the in vitro fibrin mechanical instability. The strategy consists of adding silica or chitosan-silica materials and comparing how the different materials electrokinetic-surface properties affect the achieved improvement. The siliceous materials electrostatic and steric stabilization mechanisms, together with plasma protein adsorption on their surfaces, were corroborated by DLS and ζ-potential measurements before fibrin gelling. These properties avoid phase separation, favoring homogeneous incorporation of the solid into the forming fibrin network. Young's modulus of modified fibrin hydrogels was evaluated by AFM to quantitatively measure stiffness. It increased 2.5 times with the addition of 4 mg/mL silica. A similar improvement was achieved with only 0.7 mg/mL chitosan-silica, which highlighted the contribution of hydrophilic chitosan chains to fibrinogen crosslinking. Moreover, these chains avoided the fibroblast growth inhibition onto modified fibrin hydrogels 3D culture observed with silica. In conclusion, 0.7 mg/mL chitosan-silica improved the mechanical stability of fibrin hydrogels with low risks of cytotoxicity. This easy-to-manipulate modified fibrin hydrogel makes it suitable as a wound dressing biomaterial.

Design and Characterization of Sodium Alginate and Poly(vinyl) Alcohol Hydrogels for Enhanced Skin Delivery of Quercetin

Nature has led to the discovery of biopolymers with noteworthy pharmaceutical applications. Blended biopolymers have demonstrated promising characteristics when compared with their individual counterparts. Sodium alginate (SA) is a marine polymer that has demonstrated the ability to form hydrogels, an interesting property for the development of cutaneous formulations. Predicting the good performance of blended biopolymers, a novel series of hybrid hydrogels based on SA and poly(vinyl) alcohol (PVA) were prepared. Quercetin, a natural polyphenolic flavonoid commonly found in fruits and vegetables, is widely known for its strong anti-inflammatory and antioxidant activity, thus with potential applications against melanoma, dermatitis, psoriasis, and skin ageing. Here, hydrogels were produced at different ratios of SA and PVA. The surface morphology, structure, interaction of polymers, the capacity to absorb water and the entrapment efficiency of quercetin were evaluated for the blended hydrogels. Targeting the cutaneous application of the formulations, the rheological properties of all unloaded and quercetin-loaded hydrogels revealed pseudoplastic behavior, evidence of non-thixotropy, good resistance to deformation, and profile maintenance with temperatures ranging from 20 °C up to 40 °C. The incorporation of quercetin in the hydrogel retained its antioxidant activity, confirmed by radical scavenging assays (ABTS and DPPH). The permeability of quercetin through the skin showed different penetration/permeation profiles according to the hydrogel's blend. This behavior will allow the selection of SA-PVA at 2/1 ratio for a local and prolonged skin effect, making the use of these hydrogels a good solution to consider for the treatment of skin ageing and inflammation.

Regenerative Wound Dressings for Skin Cancer

Skin cancer is considered the most prevalent cancer type globally, with a continuously increasing prevalence and mortality growth rate. Additionally, the high risk of recurrence makes skin cancer treatment among the most expensive of all cancers, with average costs estimated to double within 5 years. Although tumor excision is the most effective approach among the available strategies, surgical interventions could be disfiguring, requiring additional skin grafts for covering the defects. In this context, post-surgery management should involve the application of wound dressings for promoting skin regeneration and preventing tumor recurrence and microbial infections, which still represents a considerable clinical challenge. Therefore, this paper aims to provide an up-to-date overview regarding the current status of regenerative wound dressings for skin cancer therapy. Specifically, the recent discoveries in natural biocompounds as anti-cancer agents for skin cancer treatment and the most intensively studied biomaterials for bioactive wound dressing development will be described.

Surface refined AuQuercetin nanoconjugate stimulates dermal cell migration: possible implication in wound healing

Refining nutraceutical conjugated metal nanoparticles (NPs) and understanding their interactions with the cellular micro-environment is necessary for their application in nanomedicine. In the present experiment, we studied the effect of quercetin functionalized gold nanoparticles (Au^QurNP) on skin fibroblast and keratinocyte cell migration. Spherical shaped Au^QurNPs of 47 nm in size were formed due to the interaction of hydroxyl and carbonyl groups of quercetin with Au atoms as revealed by incremental algorithm-based analysis. Au^QurNP containing up to 5 μg l⁻¹ of Au with quercetin (5.2 ± 1.6 ng ml⁻¹) was least toxic to fibroblasts. Au^QurNP effectively reduced the generation of intracellular ROS (up to 63%) through free-radical scavenging activity. Au^QurNP also enhanced the rate of migration of fibroblasts (24 h) and keratinocytes (20 h) in artificially created wounds. The rate of migration of the cells towards the wound edge was in the order of Au^QurNP > control > quercetin > AuNP. Au^QurNP also significantly increased the expression of TGFβ1 protein, thereby inducing the downstream SMAD complex (SMAD 2–4). Downregulation of the inhibitory protein SMAD 7 by Au^QurNP helped in the nuclear translocation of SMADs 3 and 4. Collectively, the present in vitro study demonstrates the action of Au^QurNP on the SMAD family and the interconnected molecular mechanism leading to the cell migration process.

Au^Quercetin nano conjugates enhances cell migration via TGFβ1.

Preparation of smooth and macroporous hydrogel via hand-held blender for wound healing applications: in vitro and in vivo evaluations

Wound dressings play an indispensable role in wound healing. However, traditional wound dressings have several disadvantages, such as poor mechanical properties and small pore diameters, which do not allow sufficient gas exchange. To overcome these shortcomings, this paper reports a polyvinyl alcohol (PVA)-based hydrogel physically crosslinked at -20 °C and containing polyethylene glycol (PEG) and nanohydroxyapatite (HAP). The physical and chemical properties of the hydrogels formed by different stirring methods (stirring with a glass rod or a hand-held homogenizer) were compared. The average roughness of Gel 1 (prepared using a hand-held homogenizer) is 112.6 nm, which is much lower than the average surface roughness of Gel 2 (1222 nm, prepared using a glass rod). Moreover, the hydrogel made by the unconventional mixing method (with a homogenizer) showed better performance, including a more interconnected open-pore microstructure and better mechanical properties. Finally, a full-thickness skin defect test was performed. The experimental results demonstrated that the hydrogel has considerable potential for applications in wound dressings.

Application of additive manufacturing in customized titanium mandibular implants for patients with oral tumors

The application of additive manufacturing (AM) technology has been widely used in various medical fields, including craniomaxillofacial surgery. The aim of the present study was to examine the surgical efficiency and post-operative outcomes of patient-specific titanium mandibular reconstruction using AM. Major steps in directly designing and manufacturing 3D customized titanium implants are discussed. Furthermore, pre-operative preparations, surgical procedures and post-operative treatment outcomes were compared among patients who received mandibular reconstruction using a customized 3D titanium implant, titanium reconstruction plates or vascularized autologous fibular grafting. Use of a customized titanium implant significantly improved surgical efficiency and precision. When compared with mandibular reconstruction using the two conventional approaches, patients who received the customized implant were significantly more satisfied with their facial appearance, and exhibited minimal post-operative complications in the 12-month follow-up period. Patients who underwent mandibular reconstruction using a customized titanium implant displayed improved mandibular contour symmetry, restored occlusal function, normal range of mouth opening and no temporomandibular joint related pain; all complications frequently experienced by patients who undergo conventional approaches of mandibular reconstruction.

Usage of natural chitosan membrane obtained from insect corneal lenses as a drug carrier and its potential for point of care tests

Chitosan is an indispensable biopolymer for use as a drug carrier thanks to its non-toxic, biodegradable, biocompatible, antimicrobial, and anti-oxidative nature. In previous studies, chitosan was first dissolved into weak acids and formed into gel, then used for carrying pharmaceutically active compounds such as nanoparticles, capsules, composites, and films. Using the produced chitosan gel after dissolving it in weak acids has advantages, such as ease of processing for loading the required amount of active substance and making the desired shape and size. However, dissolved chitosan loses some of its natural properties such as fibrous structure, crystallinity, and thermal stability. In this study, for the first time, three-dimensional chitosan lenses obtained from an insect's (Tabanus bovinus) compound eyes, with the original shape intact, were tested as a drug carrier. A model drug, quercetin, was loaded into chitosan membrane, and its release profile was examined. Also, a point-of-care test was conducted for both chitin and chitosan membranes. Chitin and chitosan membranes obtained from insect corneal lenses were characterized by using FTIR, TGA, elemental analysis, and surface wettability analysis as well as stereo, binocular, and scanning electron microscopies. It was observed that chitosan membrane could be used as a drug carrier material. Both chitin and chitosan membranes will be improved for lateral flow assay, and these membranes can be tested for other bioengineering applications in further studies.

Preparation and in vivo evaluation of a topical hydrogel system incorporating highly skin-permeable growth factors, quercetin, and oxygen carriers for enhanced diabetic wound-healing therapy

PURPOSE

We created and evaluated an enhanced topical delivery system featuring a combination of highly skin-permeable growth factors (GFs), quercetin (QCN), and oxygen; these synergistically accelerated re-epithelialization and granulation tissue formation of/in diabetic wounds by increasing the levels of GFs and antioxidants, and the oxygen partial pressure, at the wound site.

METHODS

To enhance the therapeutic effects of exogenous administration of GFs for the treatment of diabetic wounds, we prepared highly skin-permeable GF complexes comprised of epidermal growth factor (EGF), insulin-like growth factor-I (IGF-I), platelet-derived growth factor-A (PDGF-A), and basic fibroblast growth factor (bFGF), genetically attached, via the N-termini, to a low-molecular-weight protamine (LMWP) to form LMWP-EGF, LMWP-IGF-I, LMWP-PDGF-A, and LMWP-bFGF, respectively. Furthermore, quercetin (QCN)- and oxygen-carrying 1-bromoperfluorooctane (PFOB)-loaded nanoemulsions (QCN-NE and OXY-PFOB-NE) were developed to improve the topical delivery of QCN and oxygen, respectively. After confirming the enhanced penetration of LMWP-GFs, QCN-NE, and oxygen delivered from OXY-PFOB-NE across human epidermis, we evaluated the effects of combining LMWP-GFs, QCN-NE, and OXY-PFOB-NE on proliferation of keratinocytes and fibroblasts, and the chronic wound closure rate of a diabetic mouse model.

RESULTS

The optimal ratios of LMWP-EGF, LMWP-IGF-I, LMWP-PDGF-A, LMWP-bFGF, QCN-NE, and OXY-PFOB-NE were 1, 1, 0.02, 0.02, 0.2, and 60, respectively. Moreover, a Carbopol hydrogel containing LMWP-GFs, QCN-NE, and OXY-PFOB-NE (LMWP-GFs/QCN-NE/OXY-PFOB-NE-GEL) significantly improved scratch-wound recovery of keratinocytes and fibroblasts in vitro compared to that afforded by hydrogels containing each component alone. LMWP-GFs/QCN-NE/OXY-PFOB-NE-GEL significantly accelerated wound-healing in a diabetic mouse model, decreasing wound size by 54 and 35% compared to the vehicle and LMWP-GFs, respectively.

CONCLUSION

LMWP-GFs/QCN-NE/OXY-PFOB-NE-GEL synergistically accelerated the healing of chronic wounds, exerting both rapid and prolonged effects.

Phytomedicines containing Matricaria species for the treatment of skin diseases: A biotechnological approach

Skin diseases have a notable impact on the life of the affected and in their health conditions. In order to allow a more effective and economical treatment for such disorders, new therapeutic approaches have been continuously investigated. Due to its high therapeutic and phytochemical potential, Matricaria species emerges as a pleasant alternative, since it is an important source of bioactive secondary metabolites suitable for the treatment of varied skin diseases. Therefore, this review aimed to catalog inventions that have used Matricaria species as the active component for skin disease treatment in order to assess the status of the technological development of the fitomedicines. For this, a search of patents was performed in four specialized patent database, which have reported the discovery of pharmaceutical bioproducts that used Matricaria species in its composition for skin treatment. Therefore, it is possible to notice that the pharmaceutical industry has driven efforts and investment to produce medicines for the dermatopathies, using species of this genus as an active principle. Besides, a trend of growth has been identified for the last years, which is accompanied by the continuous publication of scientific articles on the subject. It is known that a long journey is traversed between the scientific findings and their applications in the pharmaceutical market, creating the perspective that new Matricaria-based medicines may reach the pharmaceutical market in the coming years.

Formulation and characterization of glibenclamide and quercetin-loaded chitosan nanogels targeting skin permeation

Aim: Our aim was to develop and characterize a nanogel formulation containing both glibenclamide and quercetin and to explore the permeation profile of this combination. Methods: Drug-loaded nanogel was prepared by ionic gelation. In addition, optimum encapsulation efficiencies of glibenclamide and quercetin were also obtained. The average nanoparticle size at optimum conditions was determined by Zetasizer. Results: The particle size of the nanogel was found to be 370.4 ± 4.78 nm with a polydispersity index of 0.528 ± 0.04, while the λ potential was positive in a range of 17.6 to 24.8 mV. The percentage cumulative drug release also showed favorable findings. Conclusion: The chitosan nanogel could be a potential alternative for delivering glibenclamide and quercetin through skin.

Chitosan in Biomedical Engineering: A Critical Review

Biomedical engineering seeks to enhance the quality of life by developing advanced materials and technologies. Chitosan-based biomaterials have attracted significant attention because of having unique chemical structures with desired biocompatibility and biodegradability, which play different roles in membranes, sponges and scaffolds, along with promising biological properties such as biocompatibility, biodegradability and non-toxicity. Therefore, chitosan derivatives have been widely used in a vast variety of uses, chiefly pharmaceuticals and biomedical engineering. It is attempted here to draw a comprehensive overview of chitosan emerging applications in medicine, tissue engineering, drug delivery, gene therapy, cancer therapy, ophthalmology, dentistry, bio-imaging, bio-sensing and diagnosis. The use of Stem Cells (SCs) has given an interesting feature to the use of chitosan so that regenerative medicine and therapeutic methods have benefited from chitosan-based platforms. Plenty of the most recent discussions with stimulating ideas in this field are covered that could hopefully serve as hints for more developed works in biomedical engineering.

Combining antioxidant hydrogels with self-assembled microparticles for multifunctional wound dressings

A multi-functional composite to be employed as a dressing material was prepared by combining hydrogel and microparticle systems.

Electrospun poly(vinyl) alcohol/collagen nanofibrous scaffold hybridized by graphene oxide for accelerated wound healing

Purpose:

In this study, a blend of synthetic polymer (poly(vinyl) alcohol), natural polymer (collagen type I from fish bone), and graphene oxide nanoparticles is used to fabricate a composite nanofibrous scaffold, by electrospinning, for their potential application in accelerated wound healing.

Methods:

The scaffold was characterized for its physicochemical and mechanical properties. In vitro studies were carried out using human keratinocyte cell line (HaCaT) which proved the biocompatibility of the scaffold. In vivo study using mice model was carried out and the healing pattern was evaluated using histopathological studies.

Results:

Scaffold prepared from poly(vinyl) alcohol, collagen type I from fish bone, and graphene oxide possessed better physicochemical and mechanical properties. In addition, in vivo and in vitro studies showed its accelerated wound healing properties.

Conclusion:

The scaffold with required strength and biocompatibility may be tried as a wound dressing material in large animals after getting necessary approval.

Synthesis of chitin-glucan-aldehyde-quercetin conjugate and evaluation of anticancer and antioxidant activities

In the present study, we have synthesized chitin-glucan-aldehyde-quercetin (chi-glu-ald-que) conjugate via condensation reaction. Synthesis of chitin-glucan-aldehyde (chi-glu-ald) complex was facilitated by the oxidation of chitin-glucan (chi-glu) complex. Formation of conjugate was confirmed by Proton nuclear magnetic resonance spectroscopy (¹H NMR) and Fourier-transform infrared spectroscopy (FT-IR). Morphological studies showed that after grafting of quercetin, several changes on surface were depicted and a more crystalline nature was observed. The chi-glu-ald-que conjugate displayed strong antioxidant activity. It showed 69% of 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical, DPPH* scavenging activity at 1 mg/mL and 72% of 2, 2-azinobis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical cation, ABTS*⁺ scavenging activity at 1 mg/mL concentration, which are much higher than that of chi-glu complex. The anticancer activity of chi-glu-ald-que conjugate was performed in Macrophage cancer cell lines (J774) and biocompatibility was performed in Peripheral blood mononuclear cells (PBMCs). The chi-glu-ald-que conjugate showed excellent cytotoxicity against J774 cell lines but no cytotoxicity towards PBMCs.

Development, Optimization and In Vitro/In Vivo Characterization of Collagen-Dextran Spongious Wound Dressings Loaded with Flufenamic Acid

The aim of this study was the development and optimization of some topical collagen-dextran sponges with flufenamic acid, designed to be potential dressings for burn wounds healing. The sponges were obtained by lyophilization of hydrogels based on type I fibrillar collagen gel extracted from calf hide, dextran and flufenamic acid, crosslinked and un-crosslinked, and designed according to a 3-factor, 3-level Box-Behnken experimental design. The sponges showed good fluid uptake ability quantified by a high swelling ratio. The flufenamic acid release profiles from sponges presented two stages—burst effect resulting in a rapid inflammation reduction, and gradual delivery ensuring the anti-inflammatory effect over a longer burn healing period. The resistance to enzymatic degradation was monitored through a weight loss parameter. The optimization of the sponge formulations was performed based on an experimental design technique combined with response surface methodology, followed by the Taguchi approach to select those formulations that are the least affected by the noise factors. The treatment of experimentally induced burns on animals with selected sponges accelerated the wound healing process and promoted a faster regeneration of the affected epithelial tissues compared to the control group. The results generated by the complex sponge characterization indicate that these formulations could be successfully used for burn dressing applications.

Glycosaminoglycan-based resorbable polymer composites in tissue refurbishment

Regeneration of tissue structure with the aid of bioactive polymer matrices/composites and scaffolds for respective applications is one of the emerging areas of biomedical engineering. Recent advances in conjugated glycosaminoglycan (GAG) hybrids using natural and synthetic polymers have opened new avenues for producing a wide variety of resorbable polymer matrices. These hybrid scaffolds are low-immunogenic, highly biocompatible and biodegradable with incredible mechanical and tensile properties. GAG-based resorbable polymeric matrices are being exploited in migration of stem cells, cartilage and bone replacement/regeneration and production of scaffolds for various tissue engineering applications. In the current review, we will discuss the role of GAG-based resorbable polymer matrices in the field of regenerative medicine.