Cerium ions crosslinked sodium alginate-carboxymethyl chitosan spheres with antibacterial activity for wound healing

Choline Oxidase-Incorporated ATRP-Based Cerium Nanogels as Nanozymes for Colorimetric Detection of Hydrogen Peroxide and Choline

Choline is an important molecule in monitoring food safety and infant nutrition. Here, we report Ce nanogels synthesized by atom transfer radical polymerization (ATRP) employing Ce-coordinated acryloyl-lysine polymer brushes (Ce@SiO2 NGs) as highly efficient cascade nanozymes for colorimetric detection of choline. The synthesized Ce@SiO2 NGs demonstrated remarkable peroxidase-like activity with a porous exterior, which are essential to entrap choline oxidase (COx) to yield COx@Ce@SiO2 NGs and construct a cascade reaction system to detect choline. Immobilized COx catalyzed the oxidation of choline in food samples to produce H2O2, which subsequently induced the oxidation of chromogenic substrate 3,3',5,5'-tetramethylbenzidine (TMB) to produce blue color signals. This method enabled the selective and sensitive detection of target choline with a satisfactory linear range of 4-400 μM, which is sufficient to analyze foodborne choline. The practical utility of the COx@Ce@SiO2 NG-based assay was successfully validated to determine choline spiked in commercially available milk and infant formula with high accuracy and precision values. This approach provides a simple and affordable method of choline detection and has the potential to lead to more developments in ATRP-based nanozymes for diverse biosensing applications.

Multifunctional chitosan-based hydrogel wound dressing loaded with Acanthopanax senticosus and Osmundastrum cinnamomeum: Preparation, characterization and coagulation mechanism

Considerable potential exists for the development of natural polymer hydrogels that possess notable antibacterial and anti-inflammatory properties, along with excellent biocompatibility and mechanical attributes, to expedite the healing of skin wounds. Recent endeavors have focused on formulating an optimal hydrogel dressing for wound hemostasis and repair. In this pursuit, we have crafted a composite hydrogel using carboxymethyl chitosan and alginic acid, cross-linked with EDC/NHS, and enriched with extracts from Acanthopanax senticosus and Osmundastrum cinnamomeum. This synthesized hydrogel showcases commendable features, including significant swelling capacity (135 ± 3.6%), proficient water retention (94.421 ± 0.154%), and effective water vapor permeability (5845.011 ± 467.799 g/m2/d). Moreover, our drug-loaded hydrogels (CMCS/SA/AS/OC) have demonstrated remarkable efficacy in accelerating wound healing in both in vivo and in vitro models. On the 7th day, the wound healing rate reached 94.905% ± 0.498%, and by the 14th day, the wound was nearly fully healed (98.08% ± 0.323%) with the emergence of hair coverage. Furthermore, these hydrogels exhibited remarkable hemostatic properties, the platelet activity was 89.37% ± 1.29% and the platelet adhesion rate was 66.36% ± 1.42%. In order to elucidate the coagulation mechanism of the Acanthopanax senticosus and Osmundastrum cinnamomeum extracts, a network pharmacology approach was carried out. 41 active compounds and 107 potential therapeutic targets associated with these extracts were identified, revealing a total of 132 coagulation pathways. Platelet activation and complement and coagulation cascades pathways showed the highest levels of enrichment by KEGG analysis, serving as potential mechanisms through which the active components in AS/OC may facilitate coagulation by targeting relevant factors. In summary, our study has successfully developed an innovative drug-loaded hydrogel that not only enhances wound hemostasis and healing but also provides insights into the underlying mechanisms through network pharmacology. This work establishes a robust theoretical foundation for the medical application of our hydrogel.

Recent research advances on polysaccharide-, peptide-, and protein-based hemostatic materials: A review

Hemorrhage is a potentially life-threatening emergency that can occur at any time or place. Whether traumatic, congenital, surgical, disease-related, or drug-induced, bleeding can lead to severe complications or death. Therefore, the development of efficient hemostatic materials is critical. However, the results and prognosis demonstrated by clinical means of hemostasis do not reach expectations. With the development of technology, novel hemostatic materials have been developed from polysaccharides (chitosan, hyaluronic acid, alginate, cellulose, cyclodextrins, starch, dextran, and carrageenan), peptides (self-assembling peptides), and proteins (silk fibroin, collagen, gelatin, keratin, and thrombin). These new materials exhibit high hemostatic efficacy due to the enhancement or interaction of various hemostatic mechanisms. The main forms include adhesives, sealants, bandages, hemostatic powders, and hemostatic sponges. This article introduces the clotting process and principles of hemostatic methods and reviews the research on polysaccharide-, peptide-, and protein-based hemostatic materials in the last five years. The design ideas and hemostatic principles of polysaccharide-, peptide-, and protein-based hemostatic materials are mainly introduced. Finally, we summarize material designs, advantages, disadvantages, and challenges regarding hemostatic materials.

A pH-responsive ZC-QPP hydrogel for synergistic antibacterial and antioxidant treatment to enhance wound healing

The problems of bacterial resistance and high oxidation level severely limit wound healing. Therefore, we constructed a multifunctional platform of chitosan quaternary ammonium salts (QCS)/polyvinyl alcohol (PVA)/polyethylene glycol (PEG) hydrogels (QPP) loaded with ZnO@CeO2 (ZC-QPP). Firstly, the hydrogel was co-cross-linked by hydrogen and borate ester bonds, which allows easy adherence to a tissue surface for offering a protective barrier and moist environment for wounds. The chitosan quaternary ammonium salts due to their amino groups have inherent antibacterial properties to induce bacterial death. In response to the acidic conditions of the bacterial infection microenvironment, the borate ester bonds in the QPP hydrogel break and the ZC NCs dispersed in the hydrogel are released. The gradual dissociation of Zn2+ under acidic conditions can directly damage bacterial membranes. The wound site of bacterial infection always causes overexpression of reactive oxygen species (ROS) levels, often leading to inflammation and preventing rapid wound repair. CeO2 can eliminate excess ROS to reduce the inflammatory response. From in vitro and in vivo results, the high biosafety of the ZC-QPP hydrogel has demonstrated excellent antibacterial and antioxidant performance to enhance wound healing. Therefore, the ZC-QPP hydrogel opens a method to develop multifunctional synergistic therapeutic platforms combining enzyme-like nanomaterials with hydrogels for synergistic antibacterial and antioxidant treatment to promote wound healing.

Preparation and characterization of antibacterial, antioxidant, and biocompatible p-coumaric acid modified quaternized chitosan nanoparticles

To fabricate multifunctional nanoparticles (NPs) based on chitosan (CS) derivative, we first prepared quaternized CS (2-hydroxypropyltrimethyl ammonium chloride CS, HTCC) via a one-step approach, then synthesized p-coumaric acid (p-CA) modified HTCC (HTCC-CA) for the first time through amide reaction, and finally fabricated a series of NPs (HTCC-CA NPs) using HTCC-CAs with different substitution degrees and sodium tripolyphosphate (TPP) by ionic gelation. Newly-prepared HTCC and HTCC-CAs were characterized by FT-IR, ¹H NMR, elemental analysis (EA), full-wavelength UV scanning, silver nitrate titration, and Folin-Ciocalteu methods. DLS and TEM results demonstrated that three selected HTCC-CA NPs had moderate size (< 350 nm), good dispersion (PDI < 0.4), and positive zeta potential (11-20 mV). The HTCC-CA NPs had high antibacterial activity against six bacterial strains, and the minimum inhibitory concentration (MIC) values were almost the same as the minimum bactericidal concentration (MBC) values (250-1000 μg/mL). Also, the HTCC-CA NPs had good antioxidation (radical scavenging ratio > 65 %) and low cytotoxicity (relative cell viability >80 %) to the tested cells. Totally, HTCC-CA NPs with high antibacterial activity, great antioxidation, and low cytotoxicity might serve as new biomedical materials for promoting skin wound healing.

A Brief Review on Cerium Oxide (CeO2NPs)-Based Scaffolds: Recent Advances in Wound Healing Applications

The process of wound healing is complex and involves the interaction of multiple cells, each with a distinct role in the inflammatory, proliferative, and remodeling phases. Chronic, nonhealing wounds may result from reduced fibroblast proliferation, angiogenesis, and cellular immunity, often associated with diabetes, hypertension, vascular deficits, immunological inadequacies, and chronic renal disease. Various strategies and methodologies have been explored to develop nanomaterials for wound-healing treatment. Several nanoparticles such as gold, silver, cerium oxide and zinc possess antibacterial properties, stability, and a high surface area that promotes efficient wound healing. In this review article, we investigate the effectiveness of cerium oxide nanoparticles (CeO₂NPs) in wound healing-particularly the effects of reducing inflammation, enhancing hemostasis and proliferation, and scavenging reactive oxygen species. The mechanism enables CeO₂NPs to reduce inflammation, modulate the immunological system, and promote angiogenesis and tissue regeneration. In addition, we investigate the efficacy of cerium oxide-based scaffolds in various wound-healing applications for creating a favorable wound-healing environment. Cerium oxide nanoparticles (CeO₂NPs) exhibit antioxidant, anti-inflammatory, and regenerative characteristics, enabling them to be ideal wound healing material. Investigations have shown that CeO₂NPs can stimulate wound closure, tissue regeneration, and scar reduction. CeO₂NPs may also reduce bacterial infections and boost wound-site immunity. However, additional study is needed to determine the safety and efficacy of CeO₂NPs in wound healing and their long-term impacts on human health and the environment. The review reveals that CeO₂NPs have promising wound-healing properties, but further study is needed to understand their mechanisms of action and ensure their safety and efficacy.

Synthesis and characterization of a novel hydrogel based on carboxymethyl chitosan/sodium alginate with the ability to release simvastatin for chronic wound healing

Since wound dressing has been considered a promising strategy to improve wound healing, recent attention has been focused on the development of modern wound dressings based on synthetic and bioactive polymers. In this study, we prepared a multifunctional wound dressing based on carboxymethyl chitosan (CMC)/sodium alginate (Alg) hydrogel containing a nanostructured lipid carrier (NLC) in which simvastatin (SIM) has been encapsulated. This dressing aimed to act as a barrier against pathogens, eliminate excess exudates, and accelerate wound healing. Among various fabricated composites of dressing, the hydrogel composite with a CMC/sodium Alg ratio of 1:2 had an average pore size of about 98.44 ± 26.9 μm and showed 707 ± 31.9% swelling and a 2116 ± 79.2 g m-2per day water vapor transfer rate (WVTR), demonstrating appropriate properties for absorbing exudates and maintaining wound moisture. The NLC with optimum composition and properties had a spherical shape and uniform particle size distribution (74.46 ± 7.9 nm). The prepared nanocomposite hydrogel displayed excellent antibacterial activity againstEscherichia coliandStaphylococcus aureusas well as high biocompatibility on L929 mouse fibroblast cells. It can release the loaded SIM drug slowly and over a prolonged period of time. The highest drug release occurred (80%) within 14 d. The results showed that this novel nanocomposite could be a promising candidate as a wound dressing for treating various chronic wounds in skin tissues.

Biomaterials for Tissue Engineering Applications and Current Updates in the Field: A Comprehensive Review

Tissue engineering has emerged as an interesting field nowadays; it focuses on accelerating the auto-healing mechanism of tissues rather than organ transplantation. It involves implanting an In Vitro cultured initiative tissue or a scaffold loaded with tissue regenerating ingredients at the damaged area. Both techniques are based on the use of biodegradable, biocompatible polymers as scaffolding materials which are either derived from natural (e.g. alginates, celluloses, and zein) or synthetic sources (e.g. PLGA, PCL, and PLA). This review discusses in detail the recent applications of different biomaterials in tissue engineering highlighting the targeted tissues besides the in vitro and in vivo key findings. As well, smart biomaterials (e.g. chitosan) are fascinating candidates in the field as they are capable of elucidating a chemical or physical transformation as response to external stimuli (e.g. temperature, pH, magnetic or electric fields). Recent trends in tissue engineering are summarized in this review highlighting the use of stem cells, 3D printing techniques, and the most recent 4D printing approach which relies on the use of smart biomaterials to produce a dynamic scaffold resembling the natural tissue. Furthermore, the application of advanced tissue engineering techniques provides hope for the researchers to recognize COVID-19/host interaction, also, it presents a promising solution to rejuvenate the destroyed lung tissues.