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Porous tantalum (Ta) scaffold is a novel implant material widely used in orthopedics including joint surgery, spinal surgery, bone tumor surgery, and trauma surgery. However, porous Ta scaffolds manufactured using the traditional method have many disadvantages. We used selective laser melting (SLM) technology to manufacture porous Ta scaffolds, and the pore size was controlled to 400 μm. The compressive strength and elastic modulus of the porous scaffolds were evaluated in vitro. To evaluate the osteogenesis and osseointegration of Ta scaffolds manufactured by SLM technology, cytocompatibility in vitro and osseointegration ability in vivo were evaluated. This porous Ta scaffold group showed superior cell adhesion and proliferation results of human bone mesenchymal stem cells (hBMSCs) compared with the control porous Ti6Al4V group. Moreover, the alkaline phosphatase (ALP) activity at day 7 and the semiquantitative analysis of Alizarin red staining at day 21 demonstrated that osteogenic differentiation of hBMSCs was enhanced in the Ta group. The porous Ta scaffold was implanted into a cylindrical bone defect with a height and diameter of 1 and 0.5 cm, respectively, in the lateral femoral condyle of New Zealand rabbits. Radiographic analysis showed that the new bone formation in Ta scaffolds was higher than that in Ti6Al4V scaffolds. Histological images indicated that compared with porous Ti6Al4V scaffolds, Ta scaffolds increased bone ingrowth and osseointegration. The porous Ta scaffold manufactured by SLM not only has a regular pore shape and connectivity but also has controllable elastic modulus and compressive strength. Moreover, the osteogenesis and osseointegration results in vitro and in vivo were improved compared with those of the porous Ti6Al4V scaffold manufactured using the same technology. These findings demonstrate that the porous Ta scaffold manufactured by SLM is potentially useful for orthopedic clinical application.

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mechanical properties and biocompatibility. However, despite the dramatic improvements in implant design and perioperative management over the past decades, implant-related infection and limited longevity remain challenges for surgeons and materials scientists. In the United States, 4.3% of orthopedic implants are reported as being infected, with the annual cost of implant-related infection being expected to exceed $1.62 billion by 2020. [1] Implant-related infection comprises a complex biological process including bacterial adhesion and biofilm formation, with the latter constituting the main cause of implant failure owing to the associated antibiotic resistance and immune evasion. [2] In addition, the osseointegration between host bone and implant represents another crucial factor for achieving the long-term survival time of implants. Moreover, rapid bone-implant osseointegration may allow host cells to occupy the implant surface earlier than bacteria, a key factor to prevent bacterial adhesion and biofilm formation. [3] Therefore, an ideal implant for orthopedics and dentistry application should exhibit both anti-biofilm and osseointegration properties.Antibacterial and osteogenic design is required for ideal orthopedic implants. The excellent antimicrobial performance of silver nanoparticles (AgNPs) has attracted interest for the treatment of implant-related infections. However, the dose-dependent cytotoxicity of silver and its negative impact on bone implants restrict the further use of AgNPs coatings. Therefore, a hybrid coating containing polydopamine (PDA), hydroxyapatite (HA), AgNPs, and chitosan (CS) is prepared. Organic chelators CS and PDA that have promising biocompatibility are used to prevent the rapid release of silver ions from the AgNPs coating. The double chelating effect of PDA and CS significantly reduces silver ion release from the hybrid coating. The coating exhibits excellent anti-biofilm efficiency of 91.7%, 89.5%, and 92.0% for Staphylococcus aureus, Staphylococcus epidermidis, and Escherichia coli, respectively. In addition, the coating can significantly stimulate osteogenic differentiation of MC3T3-E1 cells and promote bone-implant osseointegration in vivo as compared to that in the control group. The longitudinal biosafety of the coating is confirmed in vivo by histological evaluation and blood tests. The results of this study indicate that the hybrid coating exhibits antibacterial properties as well as allow bone-implant osseointegration, thereby providing insight into the design of multifunctional implants for long-term orthopedic applications.

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This research aimed to develop and optimize a nanoemulsion-based formulation containing ceramide IIIB using phase-inversion composition for transdermal delivery. The effects of ethanol, propylene glycol (PG), and glycerol in octyldodecanol and Tween 80 systems on the size of the nanoemulsion region in the phase diagrams were investigated using water titration. Subsequently, ceramide IIIB loading was kept constant (0.05 wt%), and the proposed formulation and conditions were optimized via preliminary screening and experimental design. Factors such as octyldodecanol/(Tween 80:glycerol) weight ratio, water content, temperature, addition rate, and mixing rate were investigated in the preliminary screening experiment. Response surface methodology was employed to study the effect of water content (30%–70%, w/w), mixing rate (400–720 rpm), temperature (20°C–60°C), and addition rate (0.3–1.8 mL/min) on droplet size and polydispersity index. The mathematical model showed that the optimum formulation and conditions for preparation of ceramide IIIB nanoemulsion with desirable criteria were a temperature of 41.49°C, addition rate of 1.74 mL/min, water content of 55.08 wt%, and mixing rate of 720 rpm. Under optimum formulation conditions, the corresponding predicted response values for droplet size and polydispersity index were 15.51 nm and 0.12, respectively, which showed excellent agreement with the actual values (15.8 nm and 0.108, respectively), with no significant ( P >0.05) differences.