http://www.digitaljournal.com/life/health/3d-printing-could-lead-to-reduced-vaccination-rates/article/503038

3D printing could lead to reduced vaccination rates

Posted Sep 21, 2017 by Tim Sandle
The number of required individual vaccinations could fall dramatically thanks to a new scientific breakthrough, potentially leading to an increase in the vaccination rate. A new process uses drug-carrying "microparticles" to slowly release medications.
A nurse draws blood from a volunteer taking part in an Ebola vaccine trial at the Oxford Vaccine Gro...
A nurse draws blood from a volunteer taking part in an Ebola vaccine trial at the Oxford Vaccine Group Centre for Clinical Vaccinology and Tropical Medicine (CCVTM) on September 17, 2014
Steve Parsons, Pool/AFP
The basis of the new technology, which was produced by advanced 3D bio-printing, is with "microparticles". These tiny particles were developed by Massachusetts Institute of Technology scientists and engineers, and they can be packed with different medications.
The particles are capable of releasing two years’ worth of vaccine doses with a single injection. The medications are 'smart' in the sense that the carrying particles can be programmed to slowly release different medications over time. This means the scientists can create a complete library of tiny vaccine particles. These particles can be packed into a single syringe and all of the vaccines required by, say a child, administered in one go.
To protect the particles from the body's own defense mechanisms, each of the particles is sealed in a material called PLGA, which is an FDA-approved form of polymer already used in sutures and prosthetics. The casings also provide the basis of the 'smart' medicine in that the polymers can be designed in different ways to degrade at specific times, allowing for the controlled release of the medication. The basis of the different releasing times is a factor of the polymers each being of different molecular weights.
The lead researchers, Drs. Robert Langer and Ana Jaklenec, ,as CB Insights quotes, state that the particles can be thought of as polymer cups that are capable of “spilling” their contents at precise intervals. These 'cups' are produced by 3D printing. For this a new 3D printing process was required, which has been called the SEAL process for “StampEd Assembly of polymer Layers.” The SEAL technique allows for greater control during manufacture.
The specific drugs are added to the polymer cups via an automated dispensing system. Trials, using animal models, have been successful and it is expected that the technology will be adopted by many drugs manufacturers in the near future (following further study). The research has been published in the journal Science, with the study called "Fabrication of fillable microparticles and other complex 3D microstructures."