STATE COLLEGE, Pa.—A team of Penn State researchers recently discovered how to improve the cell adhesion and strength of a silicone polymer with 3D printing.
Polydimethylsiloxane (PDMS) has limitations in formability and manufacturing of devices. To obtain better mechanical characteristics and biological adhesion, researchers opted not to use the traditional molding and casting manufacturing techniques, and instead use 3D printing.
PDMS has been popular in lab-on-a-chip devices and organ-on-a-chip devices, and used for drug testing devices, disease screening and disease modeling purposes, said Ibrahaim Tarik Ozbolat, Hartz Family associate professor of engineering science and mechanics and bioengineering.
"PDMS is commonly used by researchers and they mostly use casting or micro molding techniques," said Veli Ozbolat, a postdoctoral visiting scholar in the Engineering Science and Mechanics Department.
Yet, when they 3D-printed PDMS, they found better mechanical and cell adhesion properties, he added.
"PDMS is extensively used in medical applications, but the manufacturability of PDMS devices is limited to soft-lithography and its derivatives," Veli Ozbolat said.
"We decided to 3D print PDMS, which enables the fabrication of geometrically complex shapes."
During their research, the team created a 3D-reconstructed nose and image.
"We first did a printability study for different mixing ratios, tip sizes, pressures and speeds to determine best parameters," Veli Ozbolat said.
After determining the suitable parameters to print 3D geometries, he said, print paths were generated. The print path of the human nose was taken from Cellink, and 3D printing was performed with the determined parameters.
"Cells usually do not adhere to PDMS substrates due to the hydrophobic nature of PDMS," said Madhuri Dey, a doctoral candidate in the Chemistry Department.
"However, when PDMS is coated with proteins like fibronectin, it makes the environment congenial for cell attachment by introducing certain amino acid sequences which the cells can readily adhere to," Dey said. "Thus fibronectin is a commonly used protein for growing cells on PDMS substrates.