Gold nanoparticles-supported iron oxide particles endows bone scaffolds with anti-tumor function.

Iron oxide (Fe-O) has anti-tumor properties, due to its ability of catalyzing hydrogen peroxide (HO) of tumor cells to generate reactive oxygen species (ROS) and then cause ferroptosis. Its anti-tumor performance is restricted due to insufficient HO in tumor cells. A nanomedicine, Au nanoparticles (NPs) grown on Fe-O, was integrated into poly-l-lactide (PLLA) scaffolds.

Exchange-coupled bi-magnetic nanoparticles enhance magnetothermal/chemodynamic antibacterial therapy of poly-l-lactide scaffold.

Bone implant-associated bacterial infection is a common cause of transplant failure. Chemodynamic therapy (CDT) has significant antibacterial efficacy by producing reactive oxygen species (ROS). However, the ROS permeability is restricted by the natural barrier of bacterial biofilms.

Semiconductor photocatalytic antibacterial materials and their application for bone infection treatment.

Bacterial infection in bone tissue engineering is a severe clinical issue. Traditional antimicrobial methods usually cause problems such as bacterial resistance and biosecurity. Employing semiconductor photocatalytic antibacterial materials is a more controlled and safer strategy, wherein semiconductor photocatalytic materials generate reactive oxygen species under illumination for killing bacteria by destroying their cell membranes, proteins, DNA, In this review, P-type and N-type semiconductor photocatalytic materials and their antibacterial mechanisms are introduced.

Engineering a wirelessly self-powered neural scaffold based on primary battery principle to accelerate nerve cell differentiation.

Electrical stimulation displayed tremendous potential in promoting nerve regeneration. However, the current electrical stimulation therapy required complex traversing wires and external power sources, which significantly limited its practical application. Herein, a self-powered nerve scaffold based on primary battery principle was gradient printed by laser additive manufacturing technique.

Self-augmented catabolism mediated by Se/Fe co-doped bioceramics boosts ROS storm for highly efficient antitumor therapy of bone scaffolds.

The overexpression of glutathione (GSH) within the tumor microenvironment has long been considered as the major obstacle for reactive oxygen species (ROS)-based antitumor therapies. To address this challenge, a selenite (SeO) and ferric ion co-doped hydroxyapatite (SF-HAP) nanohybrid was synthesized, which is then introduced into poly-L-lactic acid (PLLA) to prepare porous scaffold by selective laser sintering to continuously release Fe and SeO ions. Of great significance is the released SeO catabolize GSH to generate superoxide anion (O) rather than directly eliminating GSH, thereby reversing the obstacle posed by its overexpression and achieving a "waste-to-treasure" transformation.

Near-infrared light-activated nanosystem endows scaffold with controllable nitric oxide release for peripheral nerve regeneration.

The photosensitive S-nitrosocysteine (CysNO) could respond to light irradiation to produce nitric oxide (NO), exhibiting tremendous potential in accelerating peripheral nerve regeneration. However, its further application was limited by the burst release of NO and the requirement for ultraviolet excitation with low tissue penetration. Herein, a near-infrared-triggered NO controlled release nanosystem UCNP@ZIF-8/CysNO consisting of an upconversion nanoparticle (UCNP) core and zeolitic imidazolate framework-8 (ZIF-8) shell loading with CysNO was constructed, and then blended with poly-l-lactic acid powder to fabricate nerve scaffold by laser additive manufacturing technique.

Au/CeO Nanozyme Scaffold Boosts Electron and Hydrogen Transfer for NIR-Enhanced Chemodynamic Therapy.

CeO nanozymes have demonstrated the potential to enhance biological scaffolds with chemodynamic therapy. However, their catalytic efficacy is limited by the slow conversion of Ce to Ce and the lack of substrates like HO and H. To address these challenges, we adopted a dual-pronged strategy that utilized the plasmonic resonance of Au nanoparticles and their glucose-oxidase mimicry to boost electron and hydrogen transfer.

Shape/properties collaborative intelligent manufacturing of artificial bone scaffold: structural design and additive manufacturing process.

Artificial bone graft stands out for avoiding limited source of autograft as well as susceptibility to infection of allograft, which makes it a current research hotspot in the field of bone defect repair. However, traditional design and manufacturing method cannot fabricate bone scaffold that well mimics complicated bone-like shape with interconnected porous structure and multiple properties akin to human natural bone. Additive manufacturing, which can achieve implant's tailored external contour and controllable fabrication of internal microporous structure, is able to form almost any shape of designed bone scaffold via layer-by-layer process.

Corrosion Behavior and Biological Properties of ZK60/HA Composites Prepared by Laser Powder Bed Fusion.

Magnesium alloy ZK60 shows great promise as a medical metal material, but its corrosion resistance in the body is inadequate. Hydroxyapatite (HA), the primary inorganic component of human and animal bones, can form chemical bonds with body tissues at the interface, promoting the deposition of phosphorus products and creating a dense calcium and phosphorus layer. To enhance the properties of ZK60, HA was added to create HA/ZK60 composite materials.

Defect engineering synergistically boosts the catalytic activity of Fe-MoO for highly efficient breast mesh antitumor therapy.

The demand for breast mesh with antitumor properties is critical in post-mastectomy breast reconstruction to prevent local tumor recurrence. Molybdenum-based oxide (MoO) exhibits enzyme-like activities by catalyzing endogenous hydrogen peroxide to produce reactive oxygen species for inducing tumor cell apoptosis. However, its catalytic activity is limited by insufficient active sites.

Tannic acid based multifunctional hydrogels with mechanical stability for wound healing.

Conventional wound dressings have poor tissue adhesion and mechanical stability, restricting their applications in dynamic motion environments. Tannic acid (TA) was ideal candidates for current dressing materials due to their well-known antioxidant and anti-inflammatory properties. However, the inevitable polymerization problem of TA limited the one-step synthesis of dressings.

Synergistic effects of laser powder bed fusion and annealing on the texture-selective recrystallization of magnetostrictive Fe-Ga-NbC alloys for biomedical applications.

Introduction: Magnetostrictive Fe-Ga alloys have garnered extensive attention owing to their excellent magnetic properties and acceptable biocompatibility. Nevertheless, the polycrystalline Fe-Ga alloys currently available tend to display random texture orientations, which constrain their magnetostrictive performance.

Objectives: To regulate the texture orientation of Fe-Ga-NbC alloys and thereby enhancing magnetostriction.

Microenvironment-responsive metal-phenolic network release platform with ROS scavenging, anti-pyroptosis, and ECM regeneration for intervertebral disc degeneration.

Intervertebral disc degeneration (IVDD) can be caused by aging, injury, and genetic factors. The pathological changes associated with IVDD include the excessive accumulation of reactive oxygen species (ROS), cellular pyroptosis, and extracellular matrix (ECM) degradation. There are currently no approved specific molecular therapies for IVDD.

A Photochemically Active CuO Nanoparticle Endows Scaffolds with Good Antibacterial Performance by Efficiently Generating Reactive Oxygen Species.

Cuprous oxide (CuO) has great potential in photodynamic therapy for implant-associated infections due to its good biocompatibility and photoelectric properties. Nevertheless, the rapid recombination of electrons and holes weakens its photodynamic antibacterial effect. In this work, a new nanosystem (CuO@rGO) with excellent photodynamic performance was designed via the in situ growth of CuO on reduced graphene oxide (rGO).

Single-Atom Cu Nanozyme-Loaded Bone Scaffolds for Ferroptosis-Synergized Mild Photothermal Therapy in Osteosarcoma Treatment.

The rapid multiplication of residual tumor cells and poor reconstruction quality of new bone are considered the major challenges in the postoperative treatment of osteosarcoma. It is a promising candidate for composite bone scaffold which combines photothermal therapy (PTT) and bone regeneration induction for the local treatment of osteosarcoma. However, it is inevitable to damage the normal tissues around the tumor due to the hyperthermia of PTT, while mild heat therapy shows a limited effect on antitumor treatment as the damage can be easily repaired by stress-induced heat shock proteins (HSP).

Oxygen vacancy healing boosts the piezoelectricity of bone scaffolds.

Although barium titanate (BaTiO) presented tremendous potential in achieving self-powered stimulation to accelerate bone repair, pervasive oxygen vacancies restricted the full play of its piezoelectric performance. Herein, BaTiO-GO nanoparticles were synthesized by the growth of BaTiO on graphene oxide (GO), and subsequently introduced into poly-L-lactic acid (PLLA) powders to prepare PLLA/BaTiO-GO scaffolds by laser additive manufacturing. During the synthesis process, CO and C-OH in GO would respectively undergo cleavage and dehydrogenation at high temperature to form negatively charged oxygen groups, which were expected to occupy positively charged oxygen vacancies in BaTiO and thereby inhibit the formation of oxygen vacancies.

Laser additive manufacturing of shape memory biopolymer bone scaffold: 3D conductive network construction and electrically driven mechanism.

Introduction: The electro-actuated shape memory polymer scaffold has gained increasing attentions on the utilization of minimally invasive surgery for bone defect repair, which requires to construct an efficient conductive network to accomplish electrical-to-thermal conversion from conductive fillers to the entire matrix evenly.

Objectives: In this study, multiwall carbon nanotube (MWCNT) was convective self-assembled on the ZnO tetrapod (t-ZnO) template, where MWCNT was controlled to disperse uniformly and regulated to contact with each other effectively due to the immersion capillary force during the evaporation loss of the convective self-assembly process, leading to an interwoven layer on the t-ZnO surface.

Methods: The prepared t-ZnO@MWCNT assembly was embedded in the poly(L-lactic acid)/thermoplastic polyurethane (PLLA/TPU) scaffold fabricated via selective laser sintering to construct a 3D conductive MWCNT network for improving the electro-actuated shape memory properties.

Construction of antibacterial bone implants and their application in bone regeneration.

Bacterial infection represents a prevalent challenge during the bone repair process, often resulting in implant failure. However, the extensive use of antibiotics has limited local antibacterial effects at the infection site and is prone to side effects. In order to address the issue of bacterial infection during the transplantation of bone implants, four types of bone scaffold implants with long-term antimicrobial functionality have been constructed, including direct contact antimicrobial scaffold, dissolution-penetration antimicrobial scaffold, photocatalytic antimicrobial scaffold, and multimodal synergistic antimicrobial scaffold.

Zeolitic Imidazolate Frameworks Serve as an Interface Layer for Designing Bifunctional Bone Scaffolds with Antibacterial and Osteogenic Performance.

The integration of hydroxyapatite (HA) with broad-spectrum bactericidal nano-silver within biopolymer-based bone scaffolds not only promotes new bone growth, but also effectively prevents bacterial infections. However, there are problems such as a poor interface compatibility and easy agglomeration. In this project, zeolitic imidazolate frameworks (ZIF-8) were grown in situ on nano-HA to construct a core-shell structure, and silver was loaded into the ZIF-8 shell through ion exchange.

Direct osteogenesis and immunomodulation dual function sustained release of naringin from the polymer scaffold.

Many traditional Chinese medicine monomers, such as naringin (NG), can regulate the local immune microenvironment to benefit osteogenesis. However, the rapid release of NG from scaffolds severely influences the osteogenesis-promoting effect. Herein, NG was loaded into mesoporous bioglass (MBG) to achieve sustained release through physical adsorption and the barrier role of mesoporous channels, then MBG loaded with NG was added to poly(L-lactic acid) (PLLA) to fabricate composite scaffolds by selective laser sintering (SLS) technology.

Enhancing bone scaffold interfacial reinforcement through in situ growth of metal-organic frameworks (MOFs) on strontium carbonate: Achieving high strength and osteoimmunomodulation.

Bioceramics have been extensively used to improve osteogenesis of polymers because of their excellent bone-forming capabilities. However, the inadequate interfacial bonding between ceramics and polymers compromises their mechanical properties. In this study, zeolitic imidazolate framework-8 (ZIF-8) was grown in situ on strontium carbonate (SrCO) to construct a core-shell SrCO@ZIF-8, which was then added to poly-l-lactic acid (PLLA) to print a SrCO@ZIF-8/PLLA composite scaffold using selective sintering technology.

A CuS@g-CN heterojunction endows scaffold with synergetic antibacterial effect.

Graphitic carbon nitride (g-CN) had aroused tremendous attention in photodynamic antibacterial therapy due to its excellent energy band structure and appealing optical performance. Nevertheless, the superfast electron-hole recombination and dense biofilm formation abated its photodynamic antibacterial effect. To this end, a nanoheterojunction was synthesized via in-situ growing copper sulfide (CuS) on g-CN (CuS@g-CN).

Fe-doped mesoporous silica catalyzes ascorbic acid oxidation for tumor-specific therapy in scaffold.

Ascorbic acid (AA) is a promising antitumor agent, yet its autooxidation is too slow which constrains the further application. Fortunately, the autoxidation process can be accelerated by transition metal catalysts, especially Fe ions. In this study, AA was loaded to Fe-doped mesoporous silica (designated as AA@Fe-SiO), which was introduced into poly-L-lactic acid (PLLA) and then prepared into a scaffold.

A spatiotemporal drug release scaffold with antibiosis and bone regeneration for osteomyelitis.

Introduction: Scaffolds loaded with antibacterial agents and osteogenic drugs are considered essential tools for repairing bone defects caused by osteomyelitis. However, the simultaneous release of two drugs leads to premature osteogenesis and subsequent sequestrum formation in the pathological situation of unthorough antibiosis.

Objectives: In this study, a spatiotemporal drug-release polydopamine-functionalized mesoporous silicon nanoparticle (MSN) core/shell drug delivery system loaded with antibacterial silver (Ag) nanoparticles and osteogenic dexamethasone (Dex) was constructed and introduced into a poly-l-lactic acid (PLLA) scaffold for osteomyelitis therapy.

Highly Dispersed Cu Produced by Mechanical Stress-Activated Redox Reaction to Establish Galvanic Corrosion in Fe Implant.

Fe has immense potential for biodegradable orthopedic applications, but it degrades slowly in the physiological environment. Inducing galvanic couple by alloying Cu to Fe using ball milling is a promising approach. However, the ductile nature of Cu leads to the cold welding of a large amount of Cu powder during ball milling, which makes it difficult to disperse uniformly in the Fe matrix.