A new way to print living cells onto any surface and in almost any shape has been developed by researchers led by Houston Methodist Research Institute nanomedicine faculty member Lidong Qin. Unlike a similar inkjet printing process, almost all cells survive.
The new process, called Block-Cell-Printing (BloC-Printing), produces 2-D cell arrays in half an hour, prints the cells as close together as 5 microns (most animal cells are 10 to 30 microns wide), and allows the use of many different cell types.
“Cell printing is used in so many different ways now — for drug development and in studies of tissue regeneration, cell function, and cell-cell communication,” Qin said. “Such things can only be done when cells are alive and active. A survival rate of 50 to 80 percent is typical as cells exit the inkjet nozzles. “By comparison, we are seeing close to 100 percent of cells in BloC-Printing survive the printing process.”
BloC-Printing manipulates microfluidic physics to guide living cells into hook-like traps in the silicone mold. Cells flow down a column in the mold, past trapped cells to the next available slot, eventually creating a line of cells in a grid.
The position and spacing of the traps and the shape of the channel navigated by the cells is fully configurable during the mold’s creation. When the mold is lifted away, the living cells remain behind, adhering to the growth medium or other substrate, in prescribed formation.
The researchers also printed a grid of brain cells and gave the cells time to form synaptic and autaptic junctions. “The cell junctions we created may be useful for future neuron signal transduction and axon regeneration studies,” Qin said. “Such work could be helpful in understanding Alzheimer’s disease and other neurodegenerative diseases.”
While it is too early to predict the market cost of BloC-Printing, Qin said the materials of a single BloC mold cost about $1 (US). After the mold has been fabricated and delivered, a researcher only needs a syringe, a carefully prepared suspension of living cells, a Petri dish, and a steady hand, Qin said. Inkjet cell printers can cost between $10,000 and $200,000.
“BloC-Printing can be combined with molecular printing for many types of drug screening, RNA interference, and molecule-cell interaction studies,” he said. “We believe the technology has big potential.” While the fidelity of BloC-Printing is high, Qin said inkjet printing remains faster, and BloC-Printing cannot yet print multi-layer structures as inkjetting can.
Via Dr. Stefan Gruenwald