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In contrast to polymer bioresorbable stents (BRS) that exhibited suboptimal performance in clinical trials due to their deficient mechanical properties, metallic BRS with improved mechanical strength have made their way into the clinic and have demonstrated more promising results. In the roadmap of research and development of metallic BRS, magnesium and iron based biodegradable metal stents had been clinically used, and the zinc based biodegradable metal stents had been trailed in Mini-Pigs. In this mini-review paper, we demonstrate the current technology levels and point out the future RD direction of metallic BRS. Magnesium based BRS should target for decreasing struct thickness meanwhile balancing with enough supporting strength. Iron based BRS should move towards high efficient absorption, conversion, metabolism, elimination of its degradation products. Zn based BRS should strive to improve mechanical stability, creep resistance and biocompatibility. Future RD directions of metallic BRS should move towards new materials such as Molybdenum, intelligent stent integrated with degradable biosensors, and new stent with multiple biofunctions, such as NO release.

A new ternary compound, Mg11-xZnxSr in the Mg-Zn-Sr system was observed and studied using Scanning Electron Microscopy (SEM), Energy-Dispersive Spectroscope (EDS), X-Ray Diffraction (XRD) and Transmission Electron Microscopy (TEM). The XRD patterns were refined by the Rietveld refinement method and the results revealed that the crystallized Mg11-xZnxSr phase belonged to tetragonal I41/amd space group and had the Cd11Ba prototype. The Mg atoms were successfully doped into Zn11Sr crystal lattice by occupying Zn atomic sites. Moreover, the Rietveld refinement and computational results demonstrated a gradual decrease in the a-axis and c-axis lattice parameters with decreasing concentration levels of Mg coordination substitution in the lattice of Mg11-xZnxSr compound. The elastic constants and modulus of the Mg11-xZnxSr compounds calculated by first-principles calculations (FPC) indicated they were increased with the increasing of Zn content. The variation of hardness, d -band widths and the total density of states for Mg11-xZnxSr compounds with Zn content was discussed.

Endowing implant surfaces with combined antibacterial and osteogenic properties by drug-loaded coatings has made great strides, but how to achieve the combined excellence of infection-triggered bactericidal and

Clinical practice of therapeutic hypothermia for neuroprotection in acute cerebral ischemia has been hindered by the warming effect on the cold infusate along the pathway, which results from the poor thermal resistance of the traditional interventional catheter. In this study, thermal insulation coatings with different spray parameters and coating suspension compositions were prepared by air-spraying on a nylon substrate for biomedical application. The surface morphology and microstructure of coatings were investigated by scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy. Silk fibroin (SF) and hollow silica-based nanospheres (HSBNSs) were successfully sprayed on the nylon substrate. The thermal conductivity of the coating measured by a light flash apparatus was down to 0.00105 W/(m K). The tape test indicated that the coatings containing SF, HSBNSs and glyceryl had good adhesion, showing that air-spraying is a promising method to enhance the thermal insulation performance of traditional catheters for cerebral hypothermia therapy.

In this work, a biomimetic nanozyme catalyst with rapid and efficient self-bacteria-killing and wound-healing performances was synthesized. Through an

In situ S–Cu–FC/CuS homo-heterojunctions with NIR photocatalysis can be prepared through a redox reaction. Its photocatalysis can be enhanced by a photothermal hydrogel to eradicate bacteria under 10 min NIR irradiation and promote wound healing.

Owing to its flexibility and high treatment efficiency, phototherapy is rapidly emerging for treating bacteria-induced diseases, but how to improve the sensitivity of bacteria to reactive oxygen species (ROS) and heat simultaneously to kill bacteria under mild conditions is still a challenge. Herein, we designed a NIR light catalyst (Bi

Over the past two decades, biodegradable metals (BMs) have emerged as promising materials to fabricate temporary biomedical devices, with the purpose of avoiding potential side effects of permanent implants. In this review, we first surveyed the current status of BMs in neuroscience, and briefly summarized the representative stents for treating vascular stenosis. Then, inspired by the convincing clinical evidence on the in vivo safety of Mg alloys as cardiovascular stents, we analyzed the possibility of producing biodegradable cerebrovascular Mg alloy stents for treating ischemic stroke. For these novel applications, some key factors should also be considered in designing BM brain stents, including the anatomic features of the cerebral vasculature, hemodynamic influences, neuro-cytocompatibility and selection of alloying elements. This work may provide insights into the future design and fabrication of BM neurological devices, especially for brain stents., Graphical abstract Mg-based alloys have been used in neuroscience as filaments within nerve conduits to accelerate nerve regeneration, nerve electrode and devices for neural recording and monitoring, and stents for carotid artery stenosis and aneurysm treatment. Inspired by the convincing clinical evidence on the in vivo safety of Mg alloys as cardiovascular stents, we analyzed the possibility of producing biodegradable cerebrovascular Mg alloy stents for ischemic stroke treatment.Image 1, Highlights • The current status of the application of biodegradable metals (BM) in neuroscience was presented. • We analyzed the possibility of producing biodegradable cerebrovascular Mg alloy stents for ischemic stroke treatment. • Key factors in designing BM brain stents were discussed. • This work may provide insights into the future design and fabrication of BM neurological devices, especially for brain stents.

The comprehensively adopted copper-containing intrauterine devices (Cu-IUDs) present typical adverse effects such as bleeding and pain at the initial stage of post-implantation. The replacement of Cu material is demanded. Zinc and its alloys, the emerging biodegradable materials, exhibited contraceptive effects since 1969. In this work, we evaluated the feasibility of bulk Zn alloys as IUD active material. Using pure Cu and pure Zn as control groups, we investigated the contraceptive performance of Zn-0.5Cu and Zn-1Cu alloys via in vitro and in vivo tests. The results showed that the main corrosion product of Zn-Cu alloys is ZnO from both in vitro and in vivo studies. CaZn2(PO4)2·2H2O is formed atop after long-term immersion in simulated uterine fluid, whereas CaCO3 is generally formed atop after implantation in the rat uterine environment. The cytocompatibility of the Zn-1Cu alloy was significantly higher than that of the pure Zn and pure Cu to the human endometrial epithelial cell lines. Furthermore, the in vivo results showed that the Zn-1Cu alloy presented much improved histocompatibility, least damage and the fastest recovery on endometrium structure in comparison to pure Zn, Zn-0.5Cu and pure Cu. The systematic and comparing studies suggest that Zn-1Cu alloy can be considered as a possible candidate for IUD with great biochemical and biocompatible properties as well as high contraceptive effectiveness. STATEMENT OF SIGNIFICANCE: The existing adverse effects with the intrinsic properties of copper materials for copper-containing intrauterine devices (Cu-IUD) are of concerns in their employment. Such as burst release of cupric ions (Cu2+) at the initial stage of the Cu-IUD. Zinc and its alloys which have been emerging as a potential biodegradable material exhibited contraceptive effects since 1969. In this study, Zn-1Cu alloys displayed significantly improved biocompatibility with human uterus cells and a decreased inflammatory response within the uterus. Therefore, high antifertility efficacy of the Zn-1Cu alloy was well maintained, while the adverse effects are significantly eased, suggesting that the Zn-1Cu alloy is promising for IUD.

Biodegradable Zn-Li alloys exhibit superior mechanical performance and favorable osteogenic capability for load-bearing bone devices. Additive manufacturing (AM) endows freedom for the fabrication of bone implants of personalized structure to satisfy patient-specific needs. In this paper, AM of Zn-Li alloys was attempted for the first-time using laser powder bed fusion (LPBF), and the fabricated samples exhibited good fusion quality and high dimensional accuracy. The processing optimization, mechanical properties, in vitro corrosion behavior and cytocompatibility were investigated by using Zn-0.7Li bulk and porous samples. The ultimate tensile strength and elastic modulus of bulk samples respectively reached 416.5 MPa and 83.3 GPa, and both were the highest among various additively manufactured Zn alloys reported so far. Porous samples achieved compressive strength (18.2 MPa) and elastic modulus (298.0 MPa), which were comparable to those of cancellous bone. Porous samples exhibited a higher corrosion rate and alleviated the problem of slow degradation of Zn-Li alloys. Nevertheless, osteoblastic cells showed a more spreading and healthier morphology when adhering to the porous samples compared to the bulk samples, thus a better cytocompatibility was confirmed. This work shows tremendous potential to precisely design and modulate biodegradable Zn alloys to fulfill clinical needs by using AM technology. STATEMENT OF SIGNIFICANCE: This paper firstly studied processing optimization during laser powder bed fusion of Zn-Li alloy. Bulk and porous Zn-0.7Li samples in customized design were obtained with high formation quality. The tensile strength of bulk samples reached 416.5 MPa, while the compressive strength and modulus of porous samples reduced to 18.2 MPa and 298.0 MPa, comparable to those of bone. The weight loss of porous samples was roughly 5 times that of bulk samples; osteoblastic cells showed a more spreading and healthier morphology at porous samples, indicating improved biodegradation rate and cytocompatibility. This work shows tremendous potential to precisely design and modulate biodegradable Zn alloy porous scaffolds to fulfill clinical needs by using additive manufacturing technology.

The existing adverse effects of copper in copper-containing intrauterine devices (Cu-IUDs) have raised concerns regarding their use. These adverse effects include burst release of cupric ions (Cu2+) at the initial stage and an increasingly rough surface of the Cu-IUDs. In this study, we investigated the use of two copper alloys, Cu-38Zn and H62 as the new upgrading or alternative material for IUDs. Their corrosive properties were studied in simulated uterine fluid (SUF) by using electrochemical methods, with pure Cu as a control. We studied the in vitro long-term corrosion behaviors in SUF, cytotoxicity to uterine cells (human endometrial epithelial cells and human endometrial stromal cells), in vivo biocompatibility and contraceptive efficacy of pure Cu, H62, and Cu-38Zn. In the first month, the burst release rate of Cu2+ in the Cu-38Zn group was significantly lower than those in the pure Cu and H62 groups. The in vitro cytocompatibility Cu-38Zn was better than that of pure Cu and H62. Moreover, Cu-38Zn showed improved tissue biocompatibility in vivo experiments. Therefore, the contraceptive efficacy of the Cu-38Zn is still maintained as high as the pure Cu while the adverse effects are significantly eased, suggesting that Cu-38Zn can be a suitable potential candidate material for IUDs. STATEMENT OF SIGNIFICANCE: The existing adverse effects associated with the intrinsic properties of copper materials for copper-containing intrauterine devices (Cu-IUD) are of concern in their employment. Such as, burst release of cupric ions (Cu2+) at the initial stage and an increasingly rough surface of the Cu-IUD. In this work, Cu alloyed with a high amount of bioactive Zn was used for a Cu-IUD. The Cu-38Zn alloy exhibited reduced burst release of Cu2+ within the first month compared with the pure Cu and H62. Furthermore, the Cu-38Zn alloy displayed significantly improved biocompatibility and a much smoother surface. Therefore, high antifertility efficacy of the Cu-38Zn alloy was well maintained, while the adverse effects are significantly eased, suggesting that the Cu-38Zn alloy is promising for a Cu-IUD.

Bi2S3/Cur photocatalysis and photothermal synergistic bactericidal effect under 808 nm near infrared light.

Antimony selenide (Sb2Se3) is a promising light absorber material for solar cells because of its superior photovoltaic properties. However, the current performance of the Sb2Se3 solar cell is much lower than its theoretical value (∼32%) due to its low open-circuit voltage (VOC). In this paper, we have demonstrated inorganic vanadium oxides (VOx) as a hole transport layer (HTL) for Sb2Se3 solar cells to enhance efficiency through the VOC improvement. Here, a solution-processed VOx through the decomposition of the triisopropoxyvanadium (V) oxide is deposited on the Sb2Se3 absorber layer prepared by close-spaced sublimation (CSS). With VOx HTL, the built-in voltage (Vbi) is significantly increased, leading to improved VOC for the Sb2Se3 solar cell devices. As a result, the efficiency of the device increases from an average efficiency of 5.5% to 6.3% with the VOx.

Although perovskite solar cells (PSCs) have made revolutionary progress in terms of power conversion efficiency (PCE), to achieve long-term stability and low-cost device manufacturing for commercialization of the devices, selection of proper hole transport layer (HTL) and affordable back contact are still crucial to realize the upscale manufacturing. However, the carbon-based perovskite still faces great challenges to further improve the device performance due to the low quality of the carbon/perovskite interface. Inorganic NiOx is a superior HTL candidate due to its favorable energy band alignment, superior chemical stability, high hole mobility, and low-cost manufacturing. To address the poor interface quality of the carbon-based PSCs, we report electrospun NiOx fibers as an effective HTL, resulting in highly efficient device performance of PCEs up to 13.73% when deployed in our carbon-based PSCs. NiOx has been introduced as an interfacial layer between the perovskite and the carbon counter electrode to study its impact on interfacial modification and device performance.

As a biodegradable material, magnesium alloy has a modulus similar to that of bone, and given the biological activity of its degradation products, it has the potential to be a bone grafting material. Oxidation heat treatment is a very effective passivation method that may reduce the rate of magnesium alloy degradation. Oxidation heat treatment increases the rare earth oxide content of the scaffold as well as the corrosion resistance of the scaffold. The overall cytotoxicity of the as-printed scaffolds (APSs) and oxidation heat-treated scaffolds (OHSs) showed that OHSs accelerated cell proliferation. In the apoptosis experiment, the OHS group had a cell survival rate between that of the control group and of the as-printed group. In the osteogenic induction experiment, the alkaline phosphatase activity and the quantity of mineralized nodules were greater in the APS and OHS groups than in the control group. Marker proteins for bone growth were expressed at higher levels in the APS and OHS groups than in the control group. Therefore, oxidation heat-treated 3D printing scaffolds with good biocompatibility and osteogenic properties have great potential to be made into advanced biomaterials that can be used to fix bone defects.

While conventional nanosystems can target infected lung tissue, they cannot achieve precise cellular targeting and enhanced therapy by modulating inflammation and microbiota for effective therapy. Here, we designed a nucleus-targeted nanosystem with adenosine triphosphate (ATP) and reactive oxygen species stimuli–response to treat pneumonia coinfected with bacteria and virus that is enhanced through inflammation and microbiota regulation. The nucleus-targeted biomimetic nanosystem was prepared through the combined bacteria–macrophage membrane and loaded hypericin and ATP-responsive dibenzyl oxalate (MMHP) subsequently. The MMHP despoiled the Mg 2+ of intracellular cytoplasm in bacteria to achieve an effective bactericidal performance. Meanwhile, MMHP can target the cell nucleus and inhibit the H1N1 virus duplication by inhibiting the activity of nucleoprotein. MMHP possessed an immunomodulatory ability to reduce the inflammatory response and activate CD8 + T cells for assisted infection elimination. During the mice model, the MMHP effectively treated pneumonia coinfected with Staphylococcus aureus and H1N1 virus. Meanwhile, MMHP mediated the composition of gut microbiota to enhance the pneumonia therapy. Therefore, the dual stimuli-responsive MMHP possessed promising clinical translational potential to therapy infectious pneumonia.

High entropy oxide nanoparticles (HEO NPs) with multiple component elements possess improved stability and multiple uses for functional applications, including catalysis, data memory, and energy storage.

Large doses and long duration are often required for herbal medicines to kill bacteria effectively. Herein, a photoacoustic interfacial engineering strategy was utilized to endow curcumin (Cur, a kind of herbal medicine) with rapid and highly effective bacteria-killing efficacy, in which Cur was combined with CuS to form a hybrid material of CuS/Cur with tight contact throughiin situ/inucleation and growth on the petaloid CuS surface. Due to the different work functions of CuS and Cur, the interfacial electrons were redistributed,ii.e./i, a large number of electrons gathered on the side of CuS. In contrast, the holes gathered on the side of Cur after contact. An internal electric field was formed to drive the excited electrons to transfer from CuS to Cur, thus enhancing the separation of electron-hole pairs. Besides exerting the drug nature of Cur itself, the CuS/Cur hybrid also had photo-sono responsive ability, which endowed the hybrid with photothermal, photodynamic, and sonodynamic effects. Therefore, this Cur-based hybrid killed 99.56% ofiStaphylococcus aureus/iand 99.48% ofiEscherichia coli/iunder 808 nm near-infrared light irradiation and ultrasound successively for 15 min, which was ascribed to the synergy of ROS, hyperthermia, and released Cusup2+/suptogether with the drug properties of Cur. This work provides a strategy to enhance the therapeutic effects of herbal medicines against pathogenic bacterial infections by exciting the intrinsic properties of herbal medicines as materials through a photo-sono interfacial engineering strategy.

A novel biodegradable metal system, ZnLiCa ternary alloys, were systematically investigated both in vitro and in vivo. The ultimate tensile strength (UTS) of Zn0.8Li0.1Ca alloy reached 567.60 ± 9.56 MPa, which is comparable to pure Ti, one of the most common material used in orthopedics. The elongation of Zn0.8Li0.1Ca is 27.82 ± 18.35%, which is the highest among the ZnLiCa alloys. The in vitro degradation rate of Zn0.8Li0.1Ca alloy in simulated body fluid (SBF) showed significant acceleration than that of pure Zn. CCK-8 tests and hemocompatibility tests manifested that ZnLiCa alloys exhibit good biocompatibility. Real-time PCR showed that Zn0.8Li0.1Ca alloy successfully stimulated the expressions of osteogenesis-related genes (ALP, COL-1, OCN and Runx-2), especially the OCN. An in vivo implantation was conducted in the radius of New Zealand rabbits for 24 weeks, aiming to treat the bone defects. The Micro-CT and histological evaluations proved that the regeneration of bone defect was faster within the Zn0.8Li0.1Ca alloy scaffold than the pure Ti scaffold. Zn0.8Li0.1Ca alloy showed great potential to be applied in orthopedics, especially in the load-bearing sites., Graphical abstract Image 1, Highlights • The first research work of ZnLiCa alloys to be used as biodegradable metals. • The ultimate tensile strength (UTS) of Zn0.8Li0.1Ca alloy reached 567.60 ± 9.56 MPa, which is comparable to pure Ti, one of the most common material used in orthopedics. • Porous scaffolds made of Zn0.8Li0.1Ca showed superior bone-defect-treating effects to pure Ti scaffolds in New Zealand rabbits.

Bone defect repairs are based on bone graft fusion or replacement. Current large bone defect treatments are inadequate and lack of reliable technology. Therefore, we aimed to investigate a simple technique using three-dimensional (3D)-printed individualized porous implants without any bone grafts, osteoinductive agents, or surface biofunctionalization to treat large bone defects, and systematically study its long-term therapeutic effects and osseointegration characteristics. Twenty-six patients with large bone defects caused by tumor, infection, or trauma received treatment with individualized porous implants; among them, three typical cases underwent a detailed study. Additionally, a large segmental femur defect sheep model was used to study the osseointegration characteristics. Immediate and long-term biomechanical stability was achieved, and the animal study revealed that the bone grew into the pores with gradual remodeling, resulting in a long-term mechanically stable implant-bone complex. Advantages of 3D-printed microporous implants for the repair of bone defects included 1) that the stabilization devices were immediately designed and constructed to achieve early postoperative mobility, and 2) that osseointegration between the host bone and implants was achieved without bone grafting. Our osseointegration method, in which the “implant-bone” interface fusion concept was used instead of “bone-bone” fusion, subverts the traditional idea of osseointegration., Graphical abstract Image 1, Highlights • A new “implant-bone” interface fusion concept for large bone defect treatment was realized using 3D-printed porous implants. • Osseointegration was achieved without bone grafting. • An animal study revealed that the bone grew into the pores with gradual remodeling. • Immediate and long-term biomechanical stability was achieved by this method.

Summary Clinically, lethal viral-bacterial pneumonia is a severe threat to human health worldwide. Here, for the first time, we propose a “material-herbology” strategy, in which herbal medicines are utilized as materials or refreshed by using materialogy methods to enhance their therapeutic effect. Specifically, in this work, natural tea nanodots (TNDs, with an average size of ~3 nm) are made from several kinds of catechins extracted from Chinese black tea (Black TNDs). The antibacterial mechanism (transmembrane interactions and specific targets of amino acids) against methicillin-resistant Staphylococcus aureus (MRSA) and antiviral mechanism (inhibition of the active site of neuraminidase) against H1N1 are explored. The Black TNDs had excellent biosafety in piglets, and in combination with luteolin the optimized synergistic aerosol therapy exhibited greater advantage against lethal H1N1-MRSA pneumonia than the reported clinical therapy, owing to the rapid clearance of H1N1 and MRSA as well as the antioxidant-related anti-inflammatory effect.

Deep tissue infection, such as osteomyelitis, caused by methicillin-resistant

The ‘plainification of materials’ has been conceptualized to promote the sustainable development of materials. This perspective, for the first time in the field of biomaterials, proposes and defines ‘plain metallic biomaterials (PMBs)’ with demonstrated research and application case studies of pure titanium with high strength and toughness, and biodegradable, fine-grained and high-purity magnesium. Then, after discussing the features, benefits and opportunities of PMBs, the challenges are analyzed from both technical and regulatory aspects. Regulatory perspectives on PMB-based medical devices are also provided for the benefit of future research, development and commercialization.

Architected materials that consist of multiple subelements arranged in particular orders can demonstrate a much broader range of properties than their constituent materials. However, the rational design of these materials generally relies on experts' prior knowledge and requires painstaking effort. Here, we present a data-efficient method for the multi-property optimization of 3D-printed architected materials utilizing a machine learning (ML) cycle consisting of 3D neural networks and the finite element method (FEM). Specifically, we applied our method to orthopedic implant design. Compared to expert designs, our experience-free method designed microscale heterogeneous architectures with biocompatible elastic modulus and higher strength. Furthermore, inspired by the knowledge learned by the neural networks, we developed a machine-human synergy, adapting the ML-designed architecture to fix a macroscale, irregularly shaped animal bone defect. Such adaptation exhibits 20% higher experimental load-bearing capacity than the expert design. Thus, our method opens a new paradigm for the fast and intelligent design of architected materials with tailored mechanical, physical, and chemical properties.