Cryobioprinting has tremendous potential to solve problems to do with lack of shelf availability in traditional bioprinting by combining extrusion bioprinting and cryopreservation.In order to ensure the viability of c...Cryobioprinting has tremendous potential to solve problems to do with lack of shelf availability in traditional bioprinting by combining extrusion bioprinting and cryopreservation.In order to ensure the viability of cells in the frozen state and avoid the possible toxicity of dimethyl sulfoxide(DMSO),DMSO-free bioink design is critical for achieving successful cryobioprinting.A nontoxic gelatin methacryloyl-based bioink used in cryobioprinting is composed of cryoprotective agents(CPAs)and a buffer solution.The selection and ratio of CPAs in the bioink directly affect the survival of cells in the frozen state.However,the development of universal and efficient cryoprotective bioinks requires extensive experimentation.We first compared two commonly used CPA formulations via experiments in this study.Results show that the effect of using ethylene glycol as the permeable CPA was 6.07%better than that of glycerol.Two datasets were obtained and four machinelearning models were established to predict experimental outcomes.The predictive powers of multiple linear regression(MLR),decision tree(DT),random forest(RF),and artificial neural network(ANN)approaches were compared,suggesting an order of ANN>RF>DT>MLR.The final selected ANN model was then applied to another dataset.Results reveal that this machine-learning method can accurately predict the effects of cryoprotective bioinks composed of different CPAs.Outcomes also suggest that the formulations presented here have universality.Our findings are likely to greatly accelerate research and development on the use of bioinks for cryobioprinting.展开更多
Magnesium alloy has been generally accepted as an important biodegradable material on cardiovascular stent development for a long time. However, its limited biocompatibility, especially delayed endothelialization proc...Magnesium alloy has been generally accepted as an important biodegradable material on cardiovascular stent development for a long time. However, its limited biocompatibility, especially delayed endothelialization process restricts its further application. In this contribution, we modified the Mg-Zn-Y-Nd alloy surface with citric acid and dopamine via a layer-by-layer self-assembly assay, aiming at improving the biocompatibility of the magnesium alloy. The citric acid/dopamine(CA/PDA) layer exhibited a remarkable suppression of platelet activation/aggregation and thrombosis under 15 dyn/cm2 blood flowing. Inhibition on vascular smooth muscle cells growth and macrophages attachment/activation were also observed on this layer. In particular, the CA/PDA layer presented a promoted property for the vascular endothelial cells growth and spreading compared with the bare magnesium alloy, suggesting the pro-endotelialized function. In conclusion, this research may support potential application on surface modification of magnesium alloy based cardiovascular stents for better biocompatibility.展开更多
基金supported by the Major Science and Technology Special Project of Henan Province,China(No.171100210600)the Program of China Scholarship Council(No.201807045057)+2 种基金the High Level Talent Internationalization Training Program of Henan Province,China(No.2019004)the Scientific and Technological Research Project of Henan Province,China(Nos.212102310854 and 222102310526)the Open Foundation of the State Key Laboratory of Fluid Power and Mechatronic Systems(No.GZKF-202105)。
文摘Cryobioprinting has tremendous potential to solve problems to do with lack of shelf availability in traditional bioprinting by combining extrusion bioprinting and cryopreservation.In order to ensure the viability of cells in the frozen state and avoid the possible toxicity of dimethyl sulfoxide(DMSO),DMSO-free bioink design is critical for achieving successful cryobioprinting.A nontoxic gelatin methacryloyl-based bioink used in cryobioprinting is composed of cryoprotective agents(CPAs)and a buffer solution.The selection and ratio of CPAs in the bioink directly affect the survival of cells in the frozen state.However,the development of universal and efficient cryoprotective bioinks requires extensive experimentation.We first compared two commonly used CPA formulations via experiments in this study.Results show that the effect of using ethylene glycol as the permeable CPA was 6.07%better than that of glycerol.Two datasets were obtained and four machinelearning models were established to predict experimental outcomes.The predictive powers of multiple linear regression(MLR),decision tree(DT),random forest(RF),and artificial neural network(ANN)approaches were compared,suggesting an order of ANN>RF>DT>MLR.The final selected ANN model was then applied to another dataset.Results reveal that this machine-learning method can accurately predict the effects of cryoprotective bioinks composed of different CPAs.Outcomes also suggest that the formulations presented here have universality.Our findings are likely to greatly accelerate research and development on the use of bioinks for cryobioprinting.
基金supported by the National Key Research and Development Program of China(Grant Nos.2016YFC1102403&2017YFGX090043-04)Fostering Talents of National Natural Science Foundation of China and Henan Province(Grant No.U1504310)National Center for International Research of Micro-nano Molding Technology&Key Laboratory for Micro Molding Technology of Henan Province(Grant No.MMT2017-01)
文摘Magnesium alloy has been generally accepted as an important biodegradable material on cardiovascular stent development for a long time. However, its limited biocompatibility, especially delayed endothelialization process restricts its further application. In this contribution, we modified the Mg-Zn-Y-Nd alloy surface with citric acid and dopamine via a layer-by-layer self-assembly assay, aiming at improving the biocompatibility of the magnesium alloy. The citric acid/dopamine(CA/PDA) layer exhibited a remarkable suppression of platelet activation/aggregation and thrombosis under 15 dyn/cm2 blood flowing. Inhibition on vascular smooth muscle cells growth and macrophages attachment/activation were also observed on this layer. In particular, the CA/PDA layer presented a promoted property for the vascular endothelial cells growth and spreading compared with the bare magnesium alloy, suggesting the pro-endotelialized function. In conclusion, this research may support potential application on surface modification of magnesium alloy based cardiovascular stents for better biocompatibility.