Cryo-3D printing of nanofiber aerogels

Since 3D printing has developed into a highly available method throughout industry and research, numerous methods and techniques have emerged in life sciences. Especially in tissue engineering, several attempts of preparing scaffolds for regenerative medicine have been made so far. The requirements for scaffolds in tissue engineering, such as high porosity, appropriate pore sizes and a suitable range of mechanical properties have not yet met with 3D printing technique. Nanofiber based scaffolds have attracted a lot of attention because they can be tuned and tailor-made for the respective application. Nanofiber based aerogels are extending the benefits of nanofiber scaffolds into the 3rd dimension They are prepared by freeze-casting methods and shown excellent properties regarding density, porosity and Young's modulus. Unfortunately, those structures always require a mold for shaping of the aerogel. We herein present a novel method for the layer-by-layer fabrication of nanofiber structured aerogels. Starting from a commercially available 3D printer, a completely new hardware for the controlled deposition of nanofiber suspensions was developed. 3D printing of those suspensions was finally facilitated by including a magnetic stirring system within the printing head as well as providing a cold print bed which is capable of keeping the surface temperature at -50 °C