Copper-containing biomaterials have excellent inhibitory effect on bacteria growth by releasing copper ions at high concentration, which may have cytotoxicity at the same time. Although low ...concentration of copper ions has good cytocompatibility, the antibacterial activity is unsatisfactory. Therefore, it is of great significance to develop copper-containing biomaterials, which have excellent antibacterial property and good cytocompatibility. In this study, on considering the antagonistic effect between copper and molybdenum, molybdenum doped cuprorivaite（Mo-Cup） was synthesized by Sol-Gel method and its antibacterial properties and cell compatibility were evaluated by bacterial plate experiment and cell activity assay. The results showed that copper ions with high concentration（above 8.87 μg·mL–1） released from Mo-Cup had a good inhibitory effect on Staphylococcus aureus. In addition, because the antagonistic effect between copper and molybdenum ions released from Mo-Cup can reduce the cytotoxicity of high c
The tensile response to uniaxial deformation of polyethylene-based (Tetra-PE) and poly(ethylene oxide)-based (Tetra-PEO) networks of various strand lengths with idealized diamond connectivity have ...been studied via atomistic molecular dynamics simulations. Tetra-PE and Tetra-PEO diamond networks with the same strand length show comparable maximum extensibility but the Young’s moduli and tensile strength of the former are significantly lower than those of the latter, consistent with stronger intersegmental attractions in the amorphous Tetra-PEO networks. The stress–strain curves show that the stress in short-stranded networks increased rapidly and monotonically with strain while for long-stranded networks it increased very little at small strain and then very sharply as the limit of extensibility was approached. The soft response observed at small strains and the strain-induced crystallization that ensues at large strains rendered the deformations largely nonelastic (irreversible). Spontaneous partial crystallization of a long-stranded Tetra-PE diamond network under supercooling was demonstrated, and the resulting system was used to (1) estimate its melting point as the temperature where any crystalline material disappeared abruptly and (2) show that the presence of crystalline material in the undeformed state leads to higher stress responses upon deformation compared to amorphous samples, a result consistent with experimental observations. The spontaneous crystallization of Tetra-PEO networks at large supercooling was unsuccessful due to the slow motions of the network beads and the prohibitively long crystal nucleation times entailed.
The deep burn skin injures usually severely damage the dermis with the loss of hair follicle loss, which are difficult to regenerate. Furthermore, severe burns often accompanied with large amount of ...wound exudates making the wound moist, easily infected, and difficult to heal. Therefore, it is of great clinical significance to develop wound dressings to remove wound exudates and promote hair follicle regeneration. In this study, a sandwich-structured wound dressing (SWD) with Janus membrane property was fabricated by hot compression molding using hydrophilic zinc silicate bioceramics (Hardystonite, ZnCS) and hydrophobic polylactic acid (PLA). This unique organic/inorganic Janus membrane structure revealed excellent exudate absorption property and effectively created a dry wound environment. Meanwhile, the incorporation of ZnCS bioceramic particles endowed the dressing with the bioactivity to promote hair follicle regeneration and wound healing through the release of Zn2+ and SiO32− ions, and this bioactivity of the wound dressing is mainly attributed to the synergistic effect of Zn2+ and SiO32− to promote the recruitment, viability, and differentiation of hair follicle cells. Our study demonstrates that the utilization of the Janus membrane and synergistic effect of different type bioactive ions are effective approaches for the design of wound dressings for burn wound healing.
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•A sandwich-structured wound dressing is constructed using ZnCS ceramic powder and PLA fiber membrane (ZnCS-SWD).•ZnCS-SWD has Janus membrane property to absorb wound exudate unidirectionally from wound bed to the dressing.•The combination of Zn2+ and SiO32- ions is found to have a synergistic effect to promote burn wound healing.
A nanocomposite microneedle (ZCQ/MN) patch containing copper/zinc dual-doped mesoporous silica nanoparticles loaded with quercetin (ZCQ) was developed as a combination therapy for androgenic alopecia ...(AGA). The degradable microneedle gradually dissolves after penetration into the skin and releases the ZCQ nanoparticles. ZCQ nanoparticles release quercetin (Qu), copper (Cu2+) and zinc ions (Zn2+) subcutaneously to synergistically promote hair follicle regeneration. The mechanism of promoting hair follicle regeneration mainly includes the regulation of the main pathophysiological phenomena of AGA such as inhibition of dihydrotestosterone, inhibition of inflammation, promotion of angiogenesis and activation of hair follicle stem cells by the combination of Cu2+ and Zn2+ ions and Qu. This study demonstrates that the systematic intervention targeting different pathophysiological links of AGA by the combination of organic drug and bioactive metal ions is an effective treatment strategy for hair loss, which provides a theoretical basis for development of biomaterial based anti-hair loss therapy.
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•A nanocomposite microneedle patch (ZCQ/MN) was designed for treating androgenetic alopecia (AGA).•The active ingredients in ZCQ/MN was quercetin (Qu), copper (Cu2+) and zinc ions (Zn2+).•Cu2+ and Zn2+ ions and Qu effectively regulate the main pathophysiological phenomena of AGA.
The treatment of chronic wounds is a major challenge in regenerative medicine, and angiogenesis is known to be critical for chronic wound healing. Hot springs with temperature in the range of ...30–45 °C can promote blood circulation, and some hot spring elements including iron and silicon are also known to be active in promoting angiogenesis. Inspired by the hot spring function, we designed a novel bioactive photothermal hydrogel with “hot spring effect” based on fayalite (FA) and N, O-carboxymethyl chitosan (NOCS), which releases bioactive ions and has heating function to create hot ion environment in wound area. The hot spring-mimetic hydrogel showed significant enhancement of angiogenesis and chronic wound healing in vivo due to the in situ heating through photothermal effect combined with the bioactive ions (Fe2+ and SiO44−) released from the hydrogel. It is further confirmed that the synergetic effect of the mild heating and bioactive ions on angiogenesis was mainly because of the activation of different angiogenic factors and signaling pathways. Our study suggests that the hot spring-mimetic approach may be an effective strategy to design bioactive materials for promoting angiogenesis and tissue regeneration.
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Multipotent human bone marrow mesenchymal stem cells (hBMSCs) are commonly used as seed cells in bone tissue engineering, but their clinical application is limited due to two ...challenges. One is the expansion of hBMSCs without loss of the stemness, and the other is the stimulation of osteogenic differentiation of hBMSCs when combined with biomaterials. In this study we demonstrated an approach by firstly elucidating the functional effects and optimal concentrations of Si and Sr ions on the proliferation and osteogenic differentiation of hBMSCs, and then designing bioactive bioceramic/alginate hydrogels which could release Si and Sr bioactive ions in the same optimal concentrations range for activation of the cells in vivo. The results showed that Si and Sr ions could synergistically stimulate cell proliferation without losing the stemness. Furthermore, at higher concentrations, Si and Sr ions stimulated osteogenic differentiation instead of enhancing proliferation. The designed bioactive hydrogels revealed activity to stimulate not only the osteogenic differentiation of encapsulated hBMSCs, but also the blood vessel formation in vivo. These results suggested that the design of biomaterials based on the biological function of different material elements was an effective approach for bone tissue engineering applications.
The clinical application of multipotent human bone marrow mesenchymal stem cells (hBMSCs) in bone tissue engineering is limited due to two challenges. One is the expansion of cells without loss of the stemness, and the other is the stimulation of osteogenic differentiation of hBMSCs within the biomaterial scaffolds. Herein, we demonstrated an approach by firstly elucidating the functional effects and optimal concentrations of Si and Sr ions on the proliferation without losing stemness and osteogenic differentiation of hBMSCs, and then designing a bioactive bioceramic/alginate hydrogel which could release Si and Sr ions for in vivo activation of cells. The bioactive hydrogels revealed activity to stimulate not only osteogenic differentiation of encapsulated hBMSCs, but also the blood vessel formation in vivo. Our work provided an effective approach to design effective biomaterials for tissue engineering.
Quick and effective sterilization of drug-resistant bacteria inevitably became an ever-growing global challenge. In this study, a multifunctional composite (PDA/Cu-CS) hydrogel mainly composed of ...polydopamine (PDA) and copper-doped calcium silicate ceramic (Cu-CS) was prepared. It was confirmed that PDA/copper (PDA/Cu) complexing in the composite hydrogel played a key role in enhancing the photothermal performance and antibacterial activity. Through a unique “hot ions effect”, created by the heating of Cu ions through the photothermal effect of the composite hydrogel, the hydrogel showed high-efficiency, quick, and long-term inhibition of methicillin-resistant Staphylococcus aureus and Escherichia coli. In addition, the hydrogel possessed remarkable bioactivity to stimulate angiogenesis. The in vivo results confirmed that the “hot ions effect” of the composite hydrogel removed existing infection in the wound area efficiently and significantly promoted angiogenesis and collagen deposition during infectious skin wound healing. Our results suggested that the design of multifunctional hydrogels with “hot ions effect” may be an effective therapeutic approach for the treatment of infectious wounds.
Due to the complexity of the skin tissue structure, the regeneration of the entire skin, including skin appendages such as hair follicles, is a big challenge. In addition, skin trauma is often ...accompanied by bacterial infections that delay the wound healing. Therefore, developing wound dressings, which promote hair follicle regeneration and inhibit bacterial infection in the wound healing process, is of great clinical significance. In this study, Zn doped hollow mesoporous silica nanospheres (HMZS) were synthesized by a sol-gel method and a novel wound healing dressing was prepared by incorporation of drug ciprofloxacin hydrochloride (CiH)-loaded Zn containing mesoporous silica nanospheres (CiH-HMZS) into polycaprolactone (PCL) electrospun fibers. The CiH-HMZS/P nano-composite electrospun fibers exhibit the ability to promote angiogenesis and skin regeneration by releasing Si ions, and the activity to enhance hair follicle regeneration and inhibit bacterial growth by releasing zinc ions and achieve the synergistic antibacterial effect with both Zn ions and CiH in low concentrations. Thus, the CiH-HMZS/P nano-composite membrane is a promising multi-functional wound healing material for inhibiting bacterial growth in infected wounds and enhancing skin wound healing including hair follicle regeneration.
Developing multifunctional wound dressing with desired mechanical strength is of great significance for the treatment of different types of skin wounds. Inspired by the close relationship between ...strength and hierarchical structure of nacre, hierarchical and porous graphene oxide-chitosan-calcium silicate (GO-CTS-CS) film biomaterials are fabricated by a combination of vacuum filtration-assisted assembly and freeze-drying methods. The bioinspired hierarchical materials emulate an orderly porous lamellar micron-scale structure and the “brick-and-mortar”-layered nanostructure. The hierarchical microstructure endows the GO-CTS-CS biomaterials with good tensile strength, compatible breathability, and water absorption. Furthermore, the hierarchical GO-CTS-CS biomaterials exhibit ideal photothermal performance, leading to significant photothermal antibacterial and antitumor efficacy. Further, the hierarchical GO-CTS-CS biomaterials show stimulatory effect on in vivo chronic wound healing. Therefore, such a high performance and multifunctional biomaterial is believed to offer a promising alternative to traditional wound dressing in future.
Although it is an effective strategy to prepare high-performance materials by mimicking the hierarchical microstructure of nacre, the preparation of nacre-inspired materials in tissue engineering fields still needs to be investigated. In this work, we prepared a nacre-inspired multifunctional graphene oxide-chitosan-calcium silicate (GO-CTS-CS) biomaterial with a hierarchical microstructure. The hierarchical microstructure endows the biomaterials with desired properties of strength, breathability, and water absorption. Further, the hierarchical GO-CTS-CS biomaterial showed good photothermal antibacterial/antitumor and wound healing effects. This work may provide an approach to combine the preparation of multifunctional biomaterials with bioinspired engineering by constructing a hierarchical microstructure, indicating that the assembling hierarchical microstructure in biomaterials is of great importance for tissue engineering and regenerative medicine.
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