Co-immobilization of natural marine polysaccharides and bioactive peptides on ZE21B magnesium alloy to enhance hemocompatibility and cytocompatibility.

Degradable magnesium alloy stents are considered to be ideal candidates to replace the traditional non-degradable stents for the treatment of cardiovascular diseases. However, bare magnesium alloy stents usually degrade too fast and show poor hemocompatibility and cytocompatibility, which seriously affects their clinical use. In this study, surface modification based on the MgF layer, polydopamine (PDA) coating, fucoidan and CAG peptides was performed on the Mg-Zn-Y-Nd (ZE21B) magnesium alloy with the purpose of improving its corrosion resistance, hemocompatibility and cytocompatibility for vascular stent application.

Nucleus-targeted carbon dots as peroxidase nanozyme for photoacoustic imaging and phototherapy of tumor.

High-purity carbon dots (CDs) with a highly π-conjugated sp-hybridized graphite structure were prepared by the pulse electrolysis method using the graphite plate as raw material. Photoacoustic signal together with photothermal effect was found in the CDs-dispersed suspensions under near-infrared (NIR) irradiation. For the suspension with the CDs concentration of 500 μg/mL, the photothermal conversion efficiency is high up 64.

A Cu(Ⅱ)-eluting coating through silk fibroin film on ZE21B alloy designed for in situ endotheliazation biofunction.

In the cardiovascular field, coating containing copper used to catalyze NO (nitric oxide) production on non-degradable metal surfaces have shown unparalleled expected performance, but there are few studies on biodegradable metal surfaces. Magnesium-based biodegradable metals have been applied in cardiovascular field in large-scale because of their excellent properties. In this study, the coating of copper loaded in silk fibroin is fabricated on biodegradable ZE21B alloy.

Fucoidan/collagen composite coating on magnesium alloy for better corrosion resistance and pro-endothelialization potential.

Magnesium alloy stents (MAS) have broad application prospects in the treatment of cardiovascular diseases. However, poor corrosion resistance and biocompatibility greatly limit the clinical application of MAS. In this work, the coating consisting of MgF layer, polydopamine layer, fucoidan and collagen IV was constructed on Mg-Zn-Y-Nd (ZE21B) alloy to improve its corrosion resistance and pro-endothelialization potential.

Long-circulating gambogic acid-loaded nanodiamond composite nanosystem with inhibition of cell migration for tumor therapy.

Herein, ultra dispersed and stably suspended nanodiamonds (NDs) were demonstrated to have a high load capacity, sustained release, and ability to serve as a biocompatible vehicle for delivery anticancer drugs. NDs with size of 50-100 nm exhibited good biocompatibility in normal human liver (L-02) cells. In particular, 50 nm ND not only promoted the noticeable proliferation of the L-02 cells but also can effectively inhibited the migration of human liver carcinoma (HepG2) cells.

Surface modification of biodegradable magnesium alloy with poly (L-lactic acid) and sulfonated hyaluronic acid nanoparticles for cardiovascular application.

Magnesium (Mg) and its alloys have attracted extensive attention of researchers in the field of cardiovascular implants due to their good mechanical properties and biosafety. Constructing a multifunctional hybrid coating seems to be an effective strategy to address the insufficient endothelialization and poor corrosion resistance of Mg alloy vascular stents. In this study, a dense layer of magnesium fluoride (MgF) was prepared on the surface of Mg alloy aiming at better corrosion resistance; Thereafter, sulfonated hyaluronic acid (S-HA) was made into small sized nanoparticles (NP) which were deposited on the MgF surface by self-assembly method, followed with poly-L-lactic acid (PLLA) coating preparation by one-step pulling method.

Degradation behavior of ZE21C magnesium alloy suture anchors and their effect on ligament-bone junction repair.

Current materials comprising suture anchors used to reconstruct ligament-bone junctions still have limitation in biocompatibility, degradability or mechanical properties. Magnesium alloys are potential bone implant materials, and Mg has been shown to promote ligament-bone healing. Here, we used Mg-2 wt.

The enhanced antibacterial effect of BNNS_Van@CS/MAO coating on Mg alloy for orthopedic applications.

The development of multifunctional Mg-based active implants with controllable degradation and antibacterial capabilities has become a hotspot in the research field of biodegradable metallic materials. To this end, a BN nanosheets (BNNS) _vancomycin (Van) @chitosan (CS) nanocomposite coating containing two antibacterial components (BNNS and Van) was prepared on Mg alloys via a micro-arc oxidation (MAO) pre-treatment combined with following electrodeposition. The related characterizations of the coating show that the composite coating has a high roughness, hydrophobicity and fair corrosion resistance.

Design of single-phased magnesium alloys with typically high solubility rare earth elements for biomedical applications: Concept and proof.

Rare earth elements (REEs) have been long applied in magnesium alloys, among which the mischmetal-containing WE43 alloy has already got the CE mark approval for clinical application. A considerable amount of REEs (7 wt%) is needed in that multi-phased alloy to achieve a good combination of mechanical strength and corrosion resistance. However, the high complex RE addition accompanied with multiple second phases may bring the concern of biological hazards.

Sustained delivery of gambogic acid from mesoporous rod-structure hydroxyapatite for efficient in vitro cancer therapy.

Inspired by the critical role of nanocarrier in biomaterials modification, we synthesized a mesoporous rod-structure hydroxyapatite (MR-HAp) nanoparticles for boosting gambogic acid (GA) bioavailability in cells and improving the tumor therapy. As expected, the GA loading ratio of MR-HAp was up to about 96.97% and GA-loaded MR-HAp (MR-HAp/GA) demonstrates a sustained release performance.

Research and development strategy for biodegradable magnesium-based vascular stents: a review.

Magnesium alloys are an ideal material for biodegradable vascular stents, which can be completely absorbed in the human body, and have good biosafety and mechanical properties. However, the rapid corrosion rate and excessive localized corrosion, as well as challenges in the preparation and processing of microtubes for stents, are restricting the clinical application of magnesium-based vascular stents. In the present work we will give an overview of the recent progresses on biodegradable magnesium based vascular stents including magnesium alloy design, high-precision microtubes processing, stent shape optimisation and functional coating preparation.

pH Stimuli-Responsive, Rapidly Self-healable Coatings Enhanced the Corrosion Resistance and Osteogenic Differentiation of Mg-1Ca Osteoimplant.

Mg-Ca alloys have emerged as a promising research direction for biomedical implants in the orthopedic field. However, their clinical use is deterred by their fast corrosion rate. In this work, a pH stimuli-responsive silk-halloysite (HNT)/phytic acid (PA) self-healing coating (Silk-HNT/PA) is constructed to slow down the corrosion rate of Mg-1Ca alloy and its cell viability and osteogenic differentiation ability are enhanced.

Tailoring ZE21B Alloy with Nature-Inspired Extracellular Matrix Secreted by Micro-Patterned Smooth Muscle Cells and Endothelial Cells to Promote Surface Biocompatibility.

Delayed surface endothelialization is a bottleneck that restricts the further application of cardiovascular stents. It has been reported that the nature-inspired extracellular matrix (ECM) secreted by the hyaluronic acid (HA) micro-patterned smooth muscle cells (SMC) and endothelial cells (EC) can significantly promote surface endothelialization. However, this ECM coating obtained by decellularized method (dECM) is difficult to obtain directly on the surface of degradable magnesium (Mg) alloy.

A biodegradable magnesium alloy vascular stent structure: Design, optimisation and evaluation.

The existing biodegradable magnesium alloy stent (BMgS) structure is prone to problems, such as insufficient support capacity and early fracture at areas of concentrated stress. Herein, a stent structural design, which reduced the cross section of the traditional sin-wave stent by nearly 30% and introduces a regular arc structure in the middle of the support ring. The influence of the dual-parameter design of bending radius (r) and ring length (L) on plastic deformation, expansion and compression resistance performances are discussed.

Rapid screening alloying elements for improved corrosion resistance on the Mg(0001) surface using first principles calculations.

The poor corrosion resistance of Mg alloys is a major challenge for their applications. The corrosion of Mg alloys is mainly controlled by the anodic dissolution of Mg and the cathodic hydrogen evolution reaction (HER), which is closely related to the stability and the hydrogen adsorption of the Mg surface. In this work, the effects of alloying elements (As, Ge, Cd, Zn, Ga, Al, and Y) on the stability and the hydrogen adsorption of a Mg(0001) surface have been studied based on first principles calculations.

Sol-gel coating loaded with inhibitor on ZE21B Mg alloy for improving corrosion resistance and endothelialization aiming at potential cardiovascular application.

To improve the service performance of vascular stents, we designed/selected a series of organic compounds from commercial drugs, natural plants, and marine life as the potential corrosion inhibitors for ZE21B alloy. Paeonol condensation tyrosine (PCTyr) Schiff base was found to be the most efficient inhibitor among them. The biocompatible, self-healing, anti-corrosive sol-gel coating loaded with corrosion inhibitor was fabricated on the Mg substrate through a convenient dip-coating tactic.

Advances in coatings on magnesium alloys for cardiovascular stents - A review.

Magnesium (Mg) and its alloys, as potential biodegradable materials, have drawn wide attention in the cardiovascular stent field because of their appropriate mechanical properties and biocompatibility. Nevertheless, the occurrence of thrombosis, inflammation, and restenosis of implanted Mg alloy stents caused by their poor corrosion resistance and insufficient endothelialization restrains their anticipated clinical applications. Numerous surface treatment tactics have mainly striven to modify the Mg alloy for inhibiting its degradation rate and enduing it with biological functionality.

Microstructural Evolution and Mechanical Properties of Graphene Oxide-Reinforced Ti6Al4V Matrix Composite Fabricated Using Spark Plasma Sintering.

To achieve a further reduction in weight of titanium alloys and to satisfy the increasing demand of energy-saving for aerospace and automotive applications, a graphene oxide nanosheet-reinforced Ti6Al4V (GO/TC4) composite was successfully fabricated using spark plasma sintering (SPS). Contrary to the Widmanstätten microstructure of a monolithic TC4 sample, the microstructure of the composites displayed a typical basket-weave structure in virtue of the introduced residual tensile stress generated from the mismatch of coefficients of thermal expansion (CTE) between GO and TC4 during the phase transformation. Meanwhile, the in situ-formed TiC nanolayer and diffusion layer were identified at the GO-TC4 interface, which is expected to endow a stronger interfacial bonding.

Influence of the second phase on protein adsorption on biodegradable Mg alloys' surfaces: Comparative experimental and molecular dynamics simulation studies.

The effect of the second phase on the mechanical properties and corrosion resistance of Mg alloys has been systematically studied. However, there is limited information on the effect of the second phase on protein adsorption behavior. In the present study, the effect of the second phase on protein adsorption on the surfaces of biodegradable Mg alloys was investigated using experimental methods and molecular dynamics (MD) simulations.

Investigation of Mg-xLi-Zn alloys for potential application of biodegradable bone implant materials.

Implant therapy after osteosarcoma surgery is a major clinical challenge currently, especially the requirements for mechanical properties, degradability of the implants, and their inhibition of residual tumor cells. Biodegradable magnesium (Mg) alloy as medical bone implant material has full advantages and huge potential development space. Wherein, Mg-lithium (Li) based alloy, as an ultra-light alloy, has good properties for implants under certain conditions, and both Mg and Li have inhibitory effects on tumor cells.

Facile route to bulk ultrafine-grain steels for high strength and ductility.

Steels with sub-micrometre grain sizes usually possess high toughness and strength, which makes them promising for lightweighting technologies and energy-saving strategies. So far, the industrial fabrication of ultrafine-grained (UFG) alloys, which generally relies on the manipulation of diffusional phase transformation, has been limited to steels with austenite-to-ferrite transformation. Moreover, the limited work hardening and uniform elongation of these UFG steels hinder their widespread application.

Does Expanding or Contracting MgO Lattice Really Help with Corrosion Resistance of Mg Surface: Insights from Molecular Dynamics Simulations.

In a humid environment, water droplets on the solid surface can act as a medium to accelerate corrosion. If the solid material has hydrophobic properties, the surface of the material will remain "clean" and corrosion may be retarded to a certain extent. In theory, MgO itself is a hydrophilic material, and we can apply additional stress or strain to change its lattice constant and adjust the wetting behavior of water on the MgO surface, resulting in changes of corrosion resistance.

Application of 3D Printing Technology in Bone Tissue Engineering: A Review.

Clinically, the treatment of bone defects remains a significant challenge, as it requires autogenous bone grafts or bone graft substitutes. However, the existing biomaterials often fail to meet the clinical requirements in terms of structural support, bone induction, and controllable biodegradability. In the treatment of bone defects, 3D porous scaffolds have attracted much attention in the orthopedic field.

Stronger Adsorption of Phosphorothioate DNA Oligonucleotides on Graphene Oxide by van der Waals Forces.

Finding DNA sequences that can adsorb strongly on nanomaterials is critical for bioconjugate and biointerface chemistry. In most previous work, unmodified DNA with a phosphodiester backbone (PO DNA) were screened or selected for adsorption on inorganic surfaces. In this work, the adsorption of phosphorothioate (PS)-modified DNA (PS DNA) on graphene oxide (GO) is studied.