3-D printing improves popular polymer’s properties

Current fabrication methods limit poly(dimethylsiloxane) (PDMS)—a popular material for biomedical applications—to simple device geometries. Veli Ozbolat of Çukurova University, Ibrahim T. Ozbolat of Penn State, and coworkers have found that three-dimensional printing enables fabrication of more complex shapes and at the same time improves the mechanical and cell adhesion properties of PDMS devices compared with standard PDMS casting methods (ACS Biomater. Sci. Eng. 2017, DOI: 10.1021/acsbiomaterials.7b00646). The researchers blended two PDMS elastomers to make 3-D-printing inks with desired properties. They then used those blends to print and cast various samples. The samples made by 3-D printing were stronger, stiffer, and less porous than the ones made by casting. The researchers also found that cells adhere better to 3-D-printed PDMS devices than to ones made by casting and that coating the printed surface with the extracellular matrix protein fibronectin further improves cell adhesion. They additionally used infrared spectroscopy of the devices to show that printing doesn’t alter the surface chemistry, leading them to attribute the improved cell adhesion to surface roughness imparted by the printing process.