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Creating interconnected macropores in calcium phosphate cement (CPC) is an effective strategy to promote its degradation and osteogenesis. However, little attention has been given to the osteogenic effect of the CPC scaffolds with pre-forming and in-situ forming interconnected macropores. Herein, two types of CPC scaffolds were prepared by infiltrating CPC pastes into 3D-printed polycaprolactone (PCL) and poly(lactic-co-glycolic acid) (PLGA) networks. Meanwhile, the sacrificial PCL network within CPC was dissolved to obtain the CPC scaffold with approximately 300 μm macropores, whereas the PLGA network was retained within the CPC to obtain the PLGA/CPC scaffold. The results indicated that the PLGA/CPC scaffold showed higher degradation rate and compressive strength compared to the CPC scaffold with pre-forming interconnected macropores. However, the proliferation rate and alkaline phosphatase activity of mouse bone mesenchymal stem cells cultured with the CPC scaffold were superior to those cultured with the PLGA/CPC scaffold. In addition, greater formation of new bone and material degradation in the CPC scaffold compared to the PLGA/CPC scaffold after implanted in the rabbit femoral defects. [ABSTRACT FROM AUTHOR]

The treatment of infective bone defects remains a considerable challenge for orthopedic surgeons, primarily due to the complexities of infection control and the unsatisfactory healing of bone tissue. To solve this challenge, we have designed core/shell nanoparticles to loaded with antibacterial and osteogenic agents. Specifically, magnetocaloric CoFe2O4 (CF) nanoparticles loaded with naringin (NG) and coated with mesoporous silica (MS) were developed to construct NG-CF@MS nanoparticles. Subsequently, levofloxacin (LEV) was loaded into the MS coating, yielding NG-CF@MS-LEV nanoparticles capable of dual drug delivery. These nanoparticles were then incorporated into poly l-lactide (PLLA) powder to fabricate magnetically responsive scaffolds, which demonstrated enhanced osteogenesis and antibacterial activity under alternating magnetic field (AMF) conditions. Drug release studies showed a significant increase in NG and LEV release efficiency in the AMF setting, with a 337% increase in NG release and a 196% increase in LEV compared to non-AMF conditions. In vitro experiments further demonstrated that NG-CF@MS-LEV/PLLA scaffolds exhibited excellent osteogenic and antibacterial properties. Under the intervention of the AMF, the scaffolds displayed antibacterial rates of 98.67% and 99.38% against Escherichia coli and Staphylococcus aureus , respectively. Moreover, the scaffolds significantly promoted osteogenic differentiation and mineralization of mouse bone marrow mesenchymal stromal cells (mBMSCs), highlighting their potential as a promising therapeutic approach for repair of infected bone defects. [ABSTRACT FROM AUTHOR]

Self‐setting calcium phosphate cement (CPC) scaffold with interconnected macropores is hard to prepare without compromising its hydration reaction. Herein, an indirect 3D printing method is using to prepare CPC scaffolds. Detailedly, polycaprolactone (PCL)‐sacrificed models with different strut sizes are first printed by 3D plotting technique, and then the CPC pastes are perfused into the PCL models and then self‐setting. After the removal of the PCL models, the CPC scaffolds with different pore sizes are obtained. It is showed in the results that the prepared CPC scaffolds had uniform shape and 3D interconnected macropore structure. Meanwhile, the compressive strength of CPC scaffolds all meets the requirements of repairing cancellous bone. More interestingly, the CPC scaffold with about 300 μm in macropore size is more conducive to the ingrowth and osteogenesis differentiation of mouse bone marrow mesenchymal stem cells. As a whole, the indirect 3D printing method is a promising strategy for preparing CPC scaffolds, which are hard to form directly by 3D printing technique. [ABSTRACT FROM AUTHOR]

Implant-related bacterial infection is a serious complication, which even causes implant failure. Silver (Ag) nanoparticles are broadly used antibacterial agents due to their excellent antibacterial ability and broad-spectrum bactericidal property. However, the significance of burst release cannot be entirely ignored. In this study, Ag doped mesoporous bioactive glasses (Ag-MBG) nanospheres were synthesized using modified Stöber method, then incorporated into poly L-lactic acid (PLLA) matrix to prepare the composite scaffolds via selective laser sintering (SLS) technology. Herein, Mesoporous bioactive glasses (MBG) sol had many negatively-charged silicon hydroxyl groups, which could adsorb positively-charged Ag ions by electrostatic interaction and eventually form Si-O-Ag bonds into MBG. Moreover, MBG promoted osteoblast colonization due to its continuous release of Si ions. The results showed the Ag-MBG/PLLA scaffold could sustainedly release Ag ions for 28 days, and exhibited significantly antibacterial ability against Escherichia coli , its bacterial inhibition rate was over 80%. In addition, the composite scaffold also showed good cytocompatibility. It may be concluded that the prepared Ag-MBG/PLLA scaffold has great potential to repair implant-associated bone infection. • Ag doped mesoporous bioactive glasses nanospheres are synthesized using modified Stöber method. • Silver-doped bioglass modified scaffolds possess a sustained antibacterial efficacy. • Silver-doped bioglass modified scaffolds show good cytocompatibility. [ABSTRACT FROM AUTHOR]

It is of great challenges to repair bone defect and prevent tumor recurrence in bone tumors postoperative treatment. Bone scaffolds loaded with zoledronate (ZOL) are expected to solve these issues due to its osteogenesis and anti-tumor ability. Furthermore, ZOL needs to be sustained release to meet the requirement of long-term therapy. In this study, ZOL was loaded into amination functionalized mesoporous silicon (SBA15NH 2), and then incorporated into poly (L -lactic acid) to prepare PLLA/SBA15NH 2 -ZOL scaffold via selective laser sintering technology. On one hand, ZOL of local release not only can inhibit growth and proliferation of bone tumor cells but also inhibit osteoclast differentiation through competitive binding of receptor activator of nuclear factor (NF)-kB (RANK) in osteoclast precursors. On the other hand, amination function could change the surface charge of mesoporous silica to positive charge to enhance the absorption of ZOL, mesoporous structure and abundant amino groups of SBA15NH 2 play a barrier role and form hydrogen bond with phosphate groups of ZOL, respectively, thereby achieving its sustained release. The results showed that the loading amount of ZOL was 236.53 mg/g, and the scaffold could sustainedly release ZOL for more than 6 weeks. The scaffold inhibited proliferation of osteosarcoma cells through inducing apoptosis and cell cycle arrest. TRAP staining and F-actin ring formation experiment showed the scaffold inhibited differentiation and mature of osteoclast. Pit formation assay indicated that bone resorption activity was inhibited strongly. [Display omitted] • ZOL loaded bone scaffold was prepared by SLS technique. • The bone scaffold exhibited great tumor therapy and bone repair property in vitro. • ZOL was loaded with mesoporous silicon nanoparticle. • Functional mesoporous silicon SBA15-NH 2 ensures the sustained release of ZOL. • The scaffold exhibited a pH-dependent ZOL release. [ABSTRACT FROM AUTHOR]