Why choose 3D bioprinting?Part Ⅲ:printing in vitro 3D models for drug screening

<正>Dilemmas of current drug screening Recently,multiple technological advancements have been involved in the process of drug research and discovery.In addition,the spending on the relevant projects has doubled in the last 20 years,cumulatively increasing 28% from 2014 to 2016.However,these improvements have not led directly to an obvious increase in feasible drug candidates that successfully passed the clinical trials.According to the increased spending and stagnant clinical success rate of 10-20%,the efficiency of this project drastically decreased from around40 drugs per billion in 1950 to 0.6 drugs in 2012.The estimated costs for different drugs vary from 160 Mio.USD to over 2.5 billion USD,