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Due to the uncertainty of trauma or infection, customized bone substitutes are often required in clinic. Meanwhile, excessive use of antibiotics may lead to drug resistance. Therefore, the design of anti-infection bone tissue engineering scaffold is of very important. In this study, porous titanium alloy bone tissue engineering scaffolds were designed and fabricated by 3D printing. TiO2 nanotubes were further constructed on the scaffolds through electrochemical anodic oxidation, achieving the drug loading and anti-infection functions. The micron-level bionic pores were fabricated by the 3D printing process, and the secondary nanoscale-level nanotubes were achieved through the anodic oxidation process. Thereafter, the micro–nano structured porous bone tissue engineering scaffolds are presented. This structure features that the drug release rate can be regulated by loading the anti-infection drug minocycline and coating them with poly(lactic-co-glycolic acid) (PLGA) in the nanotubes. According to the results, the micro–nano composite porous scaffold showed uniform and controllable micro–nano pores, it may load anti-infection drugs and shown anti-infection ability. In addition, the PLGA coating may delay the drug release and maintain a sustained anti-infection function for the scaffold in a week. This study provides new ideas for designing antibacterial bone tissue engineering scaffold.

Porous structures and surface morphology of bone tissue scaffolds play an important role in improving the biocompatibility and antibacterial properties for bone repair. In this study, we investigated the effect of different anodic oxidation parameters on the nanotubes morphology in 3D printed porous titanium scaffolds. Micron-scale pores were fabricated by 3D printing first, and then the nano-scale tubes were obtained via anodizing treatments. The results demonstrated that the morphology of the nanotubes depended on the anodic oxidation time and voltage, respectively. Longer anodic oxidation led to the formation of circle-like nanotubes, and the diameter of the nanotubes increased with the voltage. The scaffolds anodized at 30 V showed the best cell proliferation potential. The presence of nanotubes on the surface of scaffold altered the adhesion of bacteria so that it improved the antibacterial properties of scaffold. The formation of nanotubes improved the drug-loading ability of the scaffold, which are used for loading of minocycline antibacterial drugs. The proposed 3D printed porous Ti6Al4V scaffold with nanotubes surface modification showed obvious antibacterial effect, which is expected to have a promising application in antibacterial bone prosthesis.

To clarify the damage losses of invasive insects, the economic cost of global invasive insects were assessed in monetized form. InvaCost database was used to analyze all insecta data, and the conservative economic costs, expenditure costs, management and loss costs, and major invasive insect species from 1970 to 2017 were counted separately, based on which generalized least squares regression, robust regression, and quantile regression 3 models to predict the possible costs from 2010 to 2019. The results showed that the economic cost due to insect invasion from 1970 to 2017 was 500 438 million dollar, with an annual average of 10 426 million dollar. The United States had the highest spending cost in the world, and China ranked second about 50 352 million dollar (340 113 million yuan), and the economic cost of Aedes spp. was the highest among all invasive insect species. The model predicted a possible economic cost of 292.362~709.725 billion dollar in the 21st century 10s, with a maximum confidence value of 367.224 billion dollar. The assessment showed that the global economic costs of invasive insects over the past few decades had been enormous, but proactive management was clearly lacking. [ABSTRACT FROM AUTHOR]