For medicine, bioprinting is a necessity and an inevitability. The demand for organs will undoubtedly continue to climb with the global median age. Yet what hurdles lie in the way of creating a renewable supply? One major engineering obstacle is properly seeding and feeding the culture in order to create a functional organ. This is because complex tissues are composed of many different types of cells precisely arranged in 3 dimensions. The approaches can be broadly divided between those using lasers and those that do not, those with scaffolds and those without. The number of possibilities multiplies when one takes into account choices in materials, growth and differentiation factors, and the types of cells one is using. Bioprinting will be a boon to transplant patients and pharmaceutical testing.
Laser assisted bioprinters were invented first. Later, Laser Induced Forward Transfer (LIFT), a technique initially invented for inorganic molecules, was appropriated by the biological sciences. After refining the technique, researchers reported a cell survival rate of 95%. This is because, unlike its predecessor, the beam does not come into direct contact with its cargo. Living cells are, not unexpectedly, quite sensitive to elevated temperatures. Laser pulses cause an absorbing layer to vaporize, resulting in the creation of droplets. The size of the droplet can be adjusted by altering the energy behind the pulse. Laser-free methods, inspired by household inkjet printers, came later.Read more