Skin is the first line of defense against pathogenic microorganisms. Any serious damage to this organ can lead to bacterial invasion and wound infection. Such infections can cause not only a delay in ...the healing process, but also more serious complications such as tissue necrosis or even sepsis, which can lead to life-threatening conditions. Therefore, wound management is a clinically critical issue. In this regard, scaffolds containing antibacterial nanobiomaterials or other agents have emerged as effective methods for reducing wound bacterial colonization and infection, thus enhancing wound healing. Because of their immunological safety, biodegradability and non-toxicity, polysaccharide-based scaffolds have piqued the interest of researchers for the delivery of antibacterial agents and nanobiomaterials for wound healing applications. This review focuses on antibacterial nanobiomaterials and agents, as well as their delivery via polysaccharide-based scaffolds for wound healing applications.
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•Delivery of antibacterial agents has been widely investigated for the treatment of infected wounds.•Polysaccharides are highly biocompatible materials that could be used for the delivery of antibacterial agents.•Various approaches have been developed for the delivery of antibacterial agents for wound healing applications using polysaccharide-based scaffolds.•Crosslinking of carbohydrate polymers plays an important role in the fabrication of hydrogels for skin tissue engineering.
Skin is susceptible to varying degrees of injury from external forces, heat, disease, and chemical corrosion. Wound dressings using tissue engineering principles can accelerate skin tissue repair, ...relieve patient pain, and reduce the formation of scars. In this study, the self-adhesive and self-healing hydrogel dressings based on quaternary ammonium chitosan (QCS), β-cyclodextrin-modified silk fibroin (CD-SF), and adamantane-modified silk fibroin (AD-SF), that was designed. The formed hydrogels not only based on the host-guest interactions between CD-SF as host polymer and AD-SF as guest polymer, also the hydrogen-bonding assembly from QCS was combined. The successful synthesis of QCS, CD-SF, and AD-SF was established using Fourier Transform Infrared spectroscopy (FT-IR) and 1H nuclear magnetic resonance (1H NMR) spectroscopy. The obtained QCS/CD-SF/AD-SF (QCA) hydrogels displayed self-adhesive, self-healing, and mechanical properties. The hydrogels exhibited antibacterial performance, combating typical Gram-negative bacteria Escherichia coli (E. coli) and Gram-positive bacteria Staphylococcus aureus (S. aureus). Further, CCK-8 assay by incubating hydrogels with NIH-3T3 cells and optical microscope inspection of cell morphology indicates the excellent cytocompatibility of the hydrogels. The designed QCA hydrogel with antibacterial properties and biocompatibility have great potential as wound dressings for wound healing treatment.
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•PES-g-IL NFMs were fabricated by combining radiation grafting with electrospinning;•The NFMs exhibit multifunctional properties, including dye and heavy metal absorption and ...antibacterial properties;•The NFMs can be easily regenerated with high absorption and desorption efficiency.
In view of the harmfulness of the pollutants in wastewater to both human being and environment, it is urgent to develop a multifunctional polymer adsorbent that can remove dyes, heavy metals and bacteria simultaneously. Herein, ionic liquid (IL) grafted Polyethersulfone (PES) (PES-g-IL) nanofibrous membranes (NFMs) were prepared by combining radiation induced grafting method and electrospinning strategy. The adsorption behavior, antibacterial property as well as reusability were examined for the obtained NFMs. It was found that the PES-g-IL NFMs exhibited excellent adsorption ability for heavy metal ions and dyes as well as good recyclability. The adsorption capacity for anionic dyes Congo Red (CR) and heavy metal ions (Cd(II)) reached 120.3 and 187.3 mg/g, respectively. The adsorption mechanism of CR was proved to be the electrostatic interaction between the NFMs and CR, while the adsorption of Cd(II) was driven by the complex between the nitrogen atoms on the imidazolium ring of the grafted ionic liquid and Cd(II). According to the adsorption kinetics, the adsorption of CR and Cd(II) was well fitted by the pseudo-second-order kinetic equation, indicating that the adsorption process was controlled by multiple steps. By calculating the thermodynamic parameters, it is indicated that the adsorption of CR and Cd(II) was a spontaneous physical adsorption process. In addition, PES-g-IL NFMs had excellent antibacterial ability. The killing rate of E. coli. was close to 99%. Given the above advantages, the PES-g-IL NFMs showed great potential in wastewater treatment.
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•A simple and efficient strategy was developed to synthesize bio-based dynamic covalent thermosets with Schiff bases and multiple hydrogen bonds from levulinic acid.•The obtained ...resin exhibited excellent thermal and mechanical properties with Tg up to 165 °C and tensile modulus up to 2422 MPa.•The resin illustrated rapid reprocessing and repairing without catalyst.•The resin showed intrinsic flame retardancy with LOI of 33.8 % and UL-94 V-0 rating.•The resin also exhibited 100% antibacterial activity against Escherichia coli and Staphylococcus aureus.
Bio-based dynamic covalent thermosets have attracted extensive attention as they are expected to break conventional thermosets' reliance on fossil resources and address the recycling issue after disposal. However, there has always been a contradiction between using bio-based feedstocks and possessing high properties, as well as a conflict between high performance and rapid recycling (reprocessing and degradation). In this work, a simple approach was developed to prepare bio-based thermosets with high performance, rapid reprocessing, high flame retardancy, and antibacterial properties enabled by in-situ generated dynamic covalent imine (Schiff base) bonds and multiple hydrogen bonds. The levulinic acid epoxy (ELA) was successfully synthesized and cured with 2-(4-aminophenyl)-1H-benzimidazol-5-amine (BIA) containing benzimidazole structures. The high concentration of Schiff bases and multiple hydrogen bonds of ELA-BIA endowed it with high glass transition temperature and mechanical properties, as well as satisfactory catalyst-free malleability, rapid reprocessing and repairing. Furthermore, due to the combined effect of the in-situ Schiff base and benzimidazole structure, ELA-BIA exhibited excellent condensed phase char formation ability, resulting in intrinsic flame retardancy with a limiting oxygen index of 33.8 % and a UL-94 V-0 rating, both of which were significantly higher than 4, 4′-diaminodiphenyl methane (DDM) cured ELA or DDM cured bisphenol A epoxy. Moreover, the Schiff bases bonded in the networks provided 100 % of the intrinsic antibacterial rates. This work provides a feasible and simple strategy for the preparation of high-performance and versatile bio-based dynamic covalent thermosets.
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•The effects of different divalent ions cross-linked SA-PAM on antibacterial properties and wound healing were investigated.•Mechanism abilities of different divalent ions ...cross-linked hydrogels on wound healing.•Zinc cross-linked hydrogels had antibacterial activity and better mechanical strength.•Strontium and zinc ions cross-linked hydrogels stimulated vascular repair and reduced wound inflammation by detecting the VEGF and TGF-β expression.
Hydrogels are widely used as debriding agents on account of providing a moist environment for wound healing, however the lack of mechanical strength, angiogenesis and antibacterial property limits their applications. In this study, we synthesized novel divalent ion cross-liking hydrogels (copper, zinc, strontium and calcium) and compared the mechanical performance, swelling ratio, antibacterial properties and biocompatibility in vitro and vivo. Thereinto, among the four divalent ions cross-linked hydrogels, copper ion crosslinking exhibited the maximum breaking strength, while strontium and zinc ion cross-linked hydrogels exhibited an excellent mechanical strength. In addition, the swelling ratio and pore size of no-ion cross-linked hydrogels was larger than ion cross-kinked hydrogels. In vitro, the improvements on wound healing after hydrogel application were evaluated by histological and molecular assays by detecting VEGF and TGF-β expression. In vitro and in vivo study results showed that zinc cross-kinked hydrogel had a spectrum of antibacterial activities, cell viability, mechanical strength and the ability of wound closure by promoting fibroblasts migration, vascularization, collagen deposition and the formation of granulation tissue.
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•HKUST-1@ LCNFs was fabricated through green and in-situ strategy successfully.•CA composite membranes were prepared with blending of HKUST-1@ LCNFs successfully.•CA composite ...membranes blended with HKUST-1@ LCNFs exhibit excellent ultrafiltration performances.•M7 has high antibacterial properties attributed to the synergistic effect of the LCNFs and HKUST-1.
To expand the application of cellulose acetate (CA) membranes in wastewater treatment, the excellent ultrafiltration performance and anti-fouling properties should be achieved. Firstly, HKUST-1@ lignocellulose nanofibrils (LCNFs) was fabricated through green and in-situ strategy successfully, which combine the characteristics of the HKUST-1 and LCNFs. Then, the blended ultrafiltration membranes with different loading of HKUST-1@LCNFs (or HKUST-1, LCNFs) were prepared by the process of phase separation, which exhibit improved pore structure, hydrophilicity, and rejection rate. Excitedly, the highest pure water permeability of 207.32 L·m−2·h−1 and the flux recovery ratio (FRR) of 90.56% were obtained with M6 membrane (0.55 wt% HKUST-1@LCNFs), which was better than that of M2 (HKUST-1) and M3 (LCNFs). It is confirmed that HKUST-1 could inhibit the accumulation of LCNFs, making it taking advantages of its hydrophilic groups. Moreover, composite membranes have attractive antibacterial properties, and >90% of E. coli were killed by M7. This work demonstrated that CA membranes blended with HKUST-1@LCNFs possesses great potential in the wastewater treatment process.
Some microorganisms can produce biofilm to create survival conditions. These biofilms are highly resistant to different environmental conditions, and dealing with them is challenging. However, it ...significantly increases bacterial resistance. Hence, most relevant articles focus on destroying and preventing microorganisms' biofilm creation, and very few articles have been written on the use of microorganism biofilm for manufacturing (especially biocomposite manufacturing). Also, biofilm production by microorganisms on the intended surface (bio-coating process) is challenging. This study planned the conditions so kombucha fungus produces biofilm on a cellulose layer (bio-coating on the surface). As a result of this action, Kombucha biofilm created a biocomposite with good barrier properties and mechanical properties (tensile index: 59 k Nm/kg, burst index: 4.8 kPa.m2/g, air permeability: 189 ml/min, porosity percentage: %10, density: 0.85 gr/cm3, contact angle:72°)The composite has such strong antibacterial properties that a significant inhibition zone was formed in the well diffusion test, and a semi-inhibition zone was also observed. This inhibition zone for the Gram-positive pathogen (S. aureus) was 10.2 mm, close to the tetracycline control sample (11 mm). (the other antibacterial test results for S. aureus: MIC:15 µl, MBC:25 µl,R-number:8,and for E.coli MIC: 15 µl, MBC:25 µl, R-number7: inhibition zone:7.4 mm) These results, along with the results of the permeability and mechanical tests, further demonstrate the operational success of this surface modification. Also, due to its properties, this biocomposite can be suggested for use in wound dressing, pharmaceutical coating, and protecting food with high nutritional value and perishability.
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Chitosan hydrogels with essential antibacterial properties and biocompatibility have great potential in tissue engineering and regeneration medicine. However, pure chitosan hydrogel could be limited ...by insufficient mechanical properties. In this work, we designed a multi-functional chitosan hydrogel based on the combination of chitosan methacrylate (CTSMA) and sulfhydrated chitosan (CTSSH), which is cross-linked simultaneously by free-radical polymerization reaction and Thiol-ene reaction. The CTSMA/CTSSH (CMS) hydrogels displayed superior tissue adhesive and mechanical properties when compared to pure CTSMA hydrogel. Additionally, the resulting hydrogels exhibited potent antimicrobial effects against both E. coli and S. aureus. Besides, the CMS hydrogels exhibited good biocompatibility as demonstrated by cytotoxicity and cell proliferation experiments using fibroblasts cells (L929) and adipose-derived stem cells (ADSCs). In vivo experiment, the repairing effect of hydrogels on full-thickness skin defect model in rats was studied. Histological and immunohistochemical staining results showed that CMS hydrogels promoted angiogenesis, dermal repair and epidermal regeneration. Overall, the study highlights the potential of the CMS hydrogels as a promising biomaterial in wound healing applications.
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•A mace-like cellulose nanocrystal@Ag nanosystem was constructed via in-situ growth.•The nanosystem was incorporated into porous PLLA scaffold fabricated via SLS.•Cellulose nanocrystal and Ag ...promoted their respective dispersion in the PLLA matrix.•The nanosystem endowed the scaffold robust antibacterial activities.•The nanosystem reinforced mechanical properties of scaffolds.
Antibacterial property for scaffolds is an urgent problem to prevent infections in bone repair. Ag nanoparticles possess excellent bactericidal activities, whereas their agglomeration restricts the full play of antibacterial property in scaffold. Herein, a mace-like nanosystem was constructed to improve their dispersion by in-situ growth of Ag nanoparticles on cellulose nanocrystal (CNC), which was labeled CNC@Ag nanosystem. Subsequently, the CNC@Ag nanosystem was introduced into poly-L-lactide (PLLA) scaffolds. Results demonstrated that the nanosystem uniformly dispersed in scaffold. The antibacterial tests demonstrated that the scaffolds possessed robust antibacterial activities against E. coli, with bacterial inhibition rate over 95%. Moreover, ion release behavior corroborated the scaffolds continuously released Ag+ for more than 28 days, which benefited from the immobilization effect of CNC on Ag. Encouragingly, the mechanical properties of the scaffolds were remarkably higher than that of PLLA/CNC scaffolds, owing to the mace-like CNC@Ag nanosystem improved the load transfer efficiency in the scaffold.
