Facile preparation of antibacterial hydrogel with multi-functions based on carboxymethyl chitosan and oligomeric procyanidin

Preparation of nano-silver containing black phosphorus based on quaternized chitosan hydrogel and evaluating its effect on skin wound healing

Hydrogels with favorable biocompatibility and antibacterial properties are essential in postoperative wound hemorrhage care, facilitating rapid wound healing. The present investigation employed electrostatic adsorption of black phosphorus nanosheets (BPNPs) and nano‑silver (AgNPs) to cross-link the protonated amino group NH3+ of quaternized chitosan (QCS) with the hydroxyl group of hyaluronic acid (HA). The electrostatic interaction between the two groups resulted in the formation of a three-dimensional gel network structure. Additionally, the hydrogel containing AgNPs deposited onto BPNPs was assessed for its antibacterial properties and effects on wound healing. Hydrogel demonstrated an outstanding drug-loading capacity and could be employed for wound closure. AgNPs loaded on the BPNPs released silver ions and exhibited potent antibacterial properties when exposed to 808 nm near-infrared (NIR) radiation. The ability of the hydrogel to promote wound healing in an acute wound model was further evaluated. The BPNPs were combined with HA and QCS in the aforementioned hydrogel system to improve adhesion, combine the photothermal and antibacterial properties of the BPNPs, and promote wound healing. Therefore, the reported hydrogels displayed excellent biocompatibility and hold significant potential for application in the field of tissue engineering for skin wound treatment.

Cowberry extract loaded chitosan hydrogel with photothermal and antioxidant properties promotes infected wound healing

Bacterial infection and oxidative stress impede clinical wound healing. Herein, the plant-derived cowberry extract (CE) was first explored as a natural photothermal agent and antioxidant to deal with bacterial infection and oxidative stress. After loading in the carboxymethyl chitosan (CMCs)/oxidized dextran (Odex) hydrogel, the photothermal effect of CE was highly enhanced by CMCs. The controlled temperature induced by CE-containing hydrogel under NIR laser irradiation could rapidly (10 min) and effectively kill Staphylococcus aureus (S. aureus, 99.3 %) and Escherichia coli (E. coli, 94.6 %). Besides, this hydrogel exhibited a fast gelation and hemostasis abilities, high stability, adhesion and ROS scavenging capabilities, as well as good injectability and biocompatibility. Above superior properties make this hydrogel to accelerate the wound healing in S. aureus-infected mice, and it is expected to be a potential clinical wound dressing.

Pharmaceutical applications of chitosan in skin regeneration: A review

Skin regeneration is the process that restores damaged tissues. When the body experiences trauma or surgical incisions, the skin and tissues on the wound surface become damaged. The body repairs this damage through complex physiological processes to restore the original structural and functional states of the affected tissues. Chitosan, a degradable natural bioactive polysaccharide, has attracted widespread attention partly owing to its excellent biocompatibility and antimicrobial properties; additionally, a modified form of this compound has been shown to promote skin regeneration. This review evaluates the recent research progress in the application of chitosan to promote skin regeneration. First, we discuss the basic principles of the extraction and preparation processes of chitosan from its source. Subsequently, we describe the functional properties of chitosan and the optimization of these properties through modification. We then focus on the existing chitosan-based biomaterials developed for clinical applications and their corresponding effects on skin regeneration, particularly in cases of diabetic and burn wounds. Finally, we explore the challenges and prospects associated with the use of chitosan in skin regeneration. Overall, this review provides a reference for related research and contributes to the further development of chitosan-based products in cutaneous skin regeneration.

Multifunctional hydrogel bioscaffolds based on polysaccharide to promote wound healing: A review

Various types of skin wounds pose challenges in terms of healing and susceptibility to infection, which can have a significant impact on physical and mental well-being, and in severe cases, may result in amputation. Conventional wound dressings often fail to provide optimal support for these wounds, thereby impeding the healing process. As a result, there has been considerable interest in the development of multifunctional polymer matrix hydrogel scaffolds for wound healing. This review offers a comprehensive review of the characteristics of polysaccharide-based hydrogel scaffolds, as well as their applications in different types of wounds. Additionally, it evaluates the advantages and disadvantages associated with various types of multifunctional polymer and polysaccharide-based hydrogel scaffolds. The objective is to provide a theoretical foundation for the utilization of multifunctional hydrogel scaffolds in promoting wound healing.

Preparation of microgels loaded with lycopene/NMN and their protective mechanism against acute liver injury

This study aimed to enhance the stability and bioavailability of lycopene (LYC) and nicotinamide mononucleotide (NMN) by incorporating them into porous microgels after loading LYC into liposomes. The particle size, zeta potential, encapsulation rate (%), scanning electron microscopy images, and stability and release kinetics characteristics in simulating digestion confirmed that the microgels had high LYC and NMN encapsulation rates (99.11% ± 0.12% and 68.98% ± 0.26%, respectively) and good stability and release characteristics. The protective effect and potential mechanism of microgels loaded with LYC and NMN on lipopolysaccharide (LPS)-induced acute liver injury in C57BL/6 mice were investigated by intragastric administration for 28 days prior to LPS exposure. The results showed that the microgels loaded with LYC and NMN significantly ameliorated LPS-induced liver injury and reduced the inflammatory response and oxidative stress. In addition, LYC and NMN can not only act on the Toll-like receptor 4 (TLR4)/MD2 complex but also regulate TLR4-related miRNAs (miR-145a-5p and miR-217-5p) in serum extracellular vesicles, thereby synergistically inhibiting the TLR4/NF-κB signaling pathway. In addition, the microgels loaded with LYC and NMN were able to enrich beneficial bacteria that produced short-chain fatty acids and reduce harmful bacteria. In conclusion, LYC and NMN protected against LPS-induced acute liver injury via inhibition of oxidative stress and inflammation, as well as regulating the gut microbiota.

β-Carotene laden antibacterial and antioxidant gelatin/polyglyceryl stearate nano-hydrogel system for burn wound healing application

Worldwide, burn wounds are severe health issues prone to bacterial infections and challenging to treat with traditional wound dressings. Therefore, a highly desirable biological macromolecules-based wound dressing with good antioxidant, antibacterial, biocompatible, and a large surface area is required. Herein, aim to develop a biological macromolecules-based physically cross-linked gelatin/polyglyceryl stearate/graphene oxide (GPGO) hydrogel to treat burn wounds. Four sets of hydrogels were prepared by varying GO concentrations. FT-IR, FE-SEM, viscosity analysis, mechanical and thermal stability confirmed the successful preparation of hydrogels with desired properties. Further, β-carotene (0.5 mg/mL) was encapsulated in hydrogels to enhance the antioxidant activity, and a cumulative release as well as kinetics at pH 6.4 and 7.4 was performed. With an increase in GO concentration, hydrogels showed sustained release of β-carotene. Among all, GPGO-3 β hydrogel showed the highest antioxidant potency (57.75 %), hemocompatible (<5 %), cytocompatible (viable with NIH 3T3 cells), cell migration, proliferation, and in vitro wound healing. Also, GPGO-3 β hydrogel showed efficient antibacterial activity (%inhibition of 85.5 % and 80.2 % and zone of 11 mm and 9.8 mm against S. aureus and E. coli). These results demonstrated the ability of GPGO-3 β hydrogel as a promising candidate for burn wound healing applications.

Effect of a New Hyaluronic Acid Hydrogel Dermal Filler Cross-Linked With Lysine Amino Acid for Skin Augmentation and Rejuvenation

BACKGROUND

Hyaluronic acid (HA) fillers are the most popular filler agents for skin rejuvenation. Although 1,4-butanediol diglycidyl ether is regarded as a relatively safe cross-linker, it still exhibits certain cytotoxicity.

OBJECTIVES

We presented here an amino acid-cross-linked HA (ACHA) which was obtained by an amidation reaction with lysine and HA. This study aimed to investigate ACHA's efficacy and safety for skin augmentation and rejuvenation.

METHODS

Rheology, compressive tests, and swelling experiments were conducted to investigate ACHA's mechanical and viscoelastic properties. The effects of ACHA on the human keratinocytes (HaCaT) cells and the human dermal fibroblast (HDF) were investigated by Transwell and wound healing assays. Its impacts on the epithelial thickness and collagen synthesis were further examined in a mouse experimental model. We recruited 50 patients with moderate to severe nasolabial folds (NLFs). The patients were randomly allocated to receive ACHA or Restylane injections. The resulting retention rates of HA and the Wrinkle Severity Rating Scale and Global Aesthetic Improvement Scale outcomes were evaluated and compared.

RESULTS

ACHA exhibited good viscoelasticity. It not only promoted migration and proliferation of HaCat and HDF and secretion of various growth factors but also increased skin thickness and promoted the generation of collagen. Patients who received ACHA had more residual volume 12 months after treatment. ACHA exhibited a promising augmentation effect in NLF correction with few adverse reactions.

CONCLUSIONS

ACHA has shown promise as a biomaterial with excellent biocompatibility and viscoelastic characteristics in both research and the clinic.See the abstract translated into Hindi, Portuguese, Korean, German, Italian, Arabic, Chinese, and Taiwanese online here: https://doi.org/10.1093/asj/sjad169.

LEVEL OF EVIDENCE: 2

Tunicate-mimetic antibacterial hydrogel based on metal ion crosslinking and chitosan functionalization for wound healing

With the increasing prevalence of drug-resistant bacterial infections and frequent occurrences of slow wound healing, the development of novel antibacterial wound dressings has become a serious challenge. Hydrogel dressings have attracted extensive attention on wound healing due to their unique three-dimensional network structures and properties. However, it is a challenge to develop natural long-acting antibacterial hydrogels with multiple functions such as excellent cell affinity, wet adhesion and mechanical properties. Inspired by the wound healing mechanism and adhesion characteristics of tunicates, a series of biomimetic antibacterial hydrogels were prepared by utilizing pyrogallol-modified chitosan (GACS) and polyvinyl alcohol (PVA) as matrix, zinc ions (Zn²⁺) as crosslinking and antibacterial agents, and ethyl N-lauroyl l-arginate hydrochloride (LAE) as the antibacterial active ingredient. The morphology, swelling, water retention, degradability, wet adhesion, biocompatibility, mechanical and rheological properties of PVA/GACS/Zn²⁺/LAE hydrogels were evaluated. And the adhesion ability conferred by the pyrogallol structures enabled the hydrogel with enhanced antibacterial effect and hemostatic ability. Moreover, the in vivo experiments on rat models with full-thickness infected wounds confirmed that PVA/GACS/Zn²⁺/LAE hydrogels could efficiently kill bacteria, significantly improve the wound microenvironment, greatly promote fibroblast proliferation and collagen deposition and ultimately accelerate wound healing. In a word, this study provided a feasible and simple way for the development of biomimetic antibacterial hydrogel dressings applied in infected wounds, which could not only seal wounds with various shapes and provide a moist and antibacterial environment for wounds, but also have certain mechanical strength, excellent wound adhesion, good biocompatibility and hemostatic performance.

A multi-crosslinking strategy of organic and inorganic compound bio-adhesive polysaccharide-based hydrogel for wound hemostasis

Polysaccharides are naturally occurring polymers with exceptional biodegradable and biocompatible qualities that are used as hemostatic agents. In this study, photoinduced CC bond network and dynamic bond network binding was used to give polysaccharide-based hydrogels the requisite mechanical strength and tissue adhesion. The designed hydrogel was composed of modified carboxymethyl chitosan (CMCS-MA) and oxidized dextran (OD), and introduced hydrogen bond network through tannic acid (TA) doping. Halloysite nanotubes (HNTs) were also added, and the effects of various doping amount on the performance of the hydrogel were examined, in order to enhance the hemostatic property of hydrogel. Experiments on vitro degradation and swelling demonstrated the strong structural stability of hydrogels. The hydrogel has improved tissue adhesion strength, with a maximum adhesion strength of 157.9 kPa, and demonstrated improved compressive strength, with a maximum compressive strength of 80.9 kPa. Meanwhile, the hydrogel had a low hemolysis rate and had no inhibition on cell proliferation. The created hydrogel exhibited a significant aggregation effect on platelets and a reduced blood clotting index (BCI). Importantly, the hydrogel can quickly adhere to seal the wound and has good hemostatic effect in vivo. Our work successfully prepared a polysaccharide-based bio-adhesive hydrogel dressing with stable structure, appropriate mechanical strength, and good hemostatic properties.

Recent advances in carboxymethyl chitosan-based materials for biomedical applications

Chitosan (CS) and its derivatives have been applied extensively in the biomedical field owing to advantageous characteristics including biodegradability, biocompatibility, antibacterial activity and adhesive properties. The low solubility of CS at physiological pH limits its use in systems requiring higher dissolving ability and a suitable drug release rate. Besides, CS can result in fast drug release because of its high swelling degree and rapid water absorption in aqueous media. As a water-soluble derivative of CS, carboxymethyl chitosan (CMC) has certain improved properties, rendering it a more suitable candidate for wound healing, drug delivery and tissue engineering applications. This review will focus on the antibacterial, anticancer and antitumor, antioxidant and antifungal bioactivities of CMC and the most recently described applications of CMC in wound healing, drug delivery, tissue engineering, bioimaging and cosmetics.

Chitosan-Based Biomaterials: Insights into Chemistry, Properties, Devices, and Their Biomedical Applications

Chitosan is a marine-origin polysaccharide obtained from the deacetylation of chitin, the main component of crustaceans’ exoskeleton, and the second most abundant in nature. Although this biopolymer has received limited attention for several decades right after its discovery, since the new millennium chitosan has emerged owing to its physicochemical, structural and biological properties, multifunctionalities and applications in several sectors. This review aims at providing an overview of chitosan properties, chemical functionalization, and the innovative biomaterials obtained thereof. Firstly, the chemical functionalization of chitosan backbone in the amino and hydroxyl groups will be addressed. Then, the review will focus on the bottom-up strategies to process a wide array of chitosan-based biomaterials. In particular, the preparation of chitosan-based hydrogels, organic–inorganic hybrids, layer-by-layer assemblies, (bio)inks and their use in the biomedical field will be covered aiming to elucidate and inspire the community to keep on exploring the unique features and properties imparted by chitosan to develop advanced biomedical devices. Given the wide body of literature that has appeared in past years, this review is far from being exhaustive. Selected works in the last 10 years will be considered.

Injectable wound dressing based on carboxymethyl chitosan triple-network hydrogel for effective wound antibacterial and hemostasis

Currently, hydrogels are widely studied for wound dressings. However, wound healing is often hindered by bacterial infection. In this study, in situ cross-linked carboxymethyl chitosan (CMCS)/oxidized dextran (OD)/poly-γ-glutamic acid (γ-PGA) (COP) hydrogel was prepared for antimicrobial and hemostasis of diffuse wounds. In the COP hydrogel, γ-PGA was able to drain the surface moisture of the wound to enhance the surface adhesion. Moreover, γ-PGA could concentrate blood by absorbing plasma, and CMCS could electrostatically adsorb negative RBCs. The antibacterial properties of CMCS and OD endowed the COP hydrogel with certain antibacterial effects. In the inhibition zone experiment, an obvious inhibition zone appeared around the COP hydrogel. In vivo studies showed that the COP hydrogel significantly inhibited bacterial growth and promoted wound healing. In the rat tail diffuse hemorrhage wound model, the COP hydrogel showed superior hemostasis ability. Therefore, the multifunctional COP hydrogel is expected to find different applications in wound hemostasis and healing.

Effect of Grape Seed Extract on Gelatin-Based Edible 3D-Hydrogels for Cultured Meat Application

Cell-cultured meat, which is artificial meat made by in vitro cultivation of animal-derived cells, has attracted a lot of interest as a potential source of protein in the future. Porous hydrogels are crucial components that can be used as an artificial extracellular matrix (ECM) to provide cell growth for generating cultured meat. In this study, we highlight the effects of grape seed extract (proanthocyanidins, PC) on the physicochemical and biological functions (bovine satellite muscle cell (BSC) growth and adhesion) of an edible gelatin (GL)-based hydrogel. The freeze-dried hydrogels had good compressive characteristics with pore sizes ranging from 100 to 300 μm. BSCs were able to grow and attach to porous GL-PC hydrogels. These studies suggested that the developed hydrogels using edible materials and made by employing a low-cost method may serve in the cell growth of muscle cells for cultured meat applications.