Tendril Climber Inspired Structure-Induced Cell Growth by Direct Writing Heterogeneous Scaffold

As a fundamental issue, cell-scaffold interaction has drawn increased attention in tissue engineering. The ability of tendril-climbers to perceive position and climb up toward the trellis in an ingenious manner induces interest. Thus, the question arises whether the cell can also grow as ingenious as the plant. Prompted by the climbing mechanism of tendril climbers, we proposed a novel method for inducing cell growth by using specially designed scaffolds with heterogeneous structures. A high-resolution 3D printing method via melt direct writing for fabricating these scaffolds was developed. By melting biodegradable polymers in the nozzle and high-voltage attraction, scaffolds with fiber diameters measuring 3μm can be printed layer by layer. Heterogeneous structures, such as various fiber diameters and pore sizes, can be freely printed in one scaffold at the different locations by adjusting correlated parameters. Owing to these properties of the scaffold, interesting phenomena of cell growth were observed. Human umbilical vein endothelial cells (HUVECs) exhibited different growth rates on the scaffold with different pore sizes. And bone marrow stem cell (BMSCs) showed several morphological characteristics on the scaffold consisting of fibers with specific diameters. Therefore, we can regulate and control cell growth to different status in one scaffold by merely designing structures. This study generally provides a structure-induced cell growth strategy for better simulating in-vivo like environment.