McHugh, 2017 SEAL MIT PolySciTech.PNG

Conventional emulsion-based methods can be used to create microparticles for drug delivery applications, however these have some drawbacks. There is little control over the distribution, structure, and spatial orientation of the particles and generally the formed particles are always spherical or nearly so. Most manufacturing techniques, such as 3D printing, lack the resolution capabilities to make micro-structured components. Recently, researchers at the Massachusetts Institute of Technology (MIT) utilized PLGA (PolyVivo AP045) from PolySciTech (www.polyscitech.com) to create a series of uniquely manufactured microstructures using a novel manufacturing technique. In this technique, the PLGA is heated and carefully pressed against a micropatterned mold to form the structure. Subsequent pressings can be applied to create more complex structures in micron dimensions. This research holds promise to generate new avenues for drug delivery by creating microparticles and structures which have precisely controlled time-release properties or functions based on shape and orientation. Read more: McHugh, Kevin J., Thanh D. Nguyen, Allison R. Linehan, David Yang, Adam M. Behrens, Sviatlana Rose, Zachary L. Tochka et al. "Fabrication of fillable microparticles and other complex 3D microstructures." Science 357, no. 6356 (2017): 1138-1142. http://science.sciencemag.org/content/357/6356/1138.abstract

 

“Abstract: Three-dimensional (3D) microstructures created by microfabrication and additive manufacturing have demonstrated value across a number of fields, ranging from biomedicine to microelectronics. However, the techniques used to create these devices each have their own characteristic set of advantages and limitations with regards to resolution, material compatibility, and geometrical constraints that determine the types of microstructures that can be formed. We describe a microfabrication method, termed StampEd Assembly of polymer Layers (SEAL), and create injectable pulsatile drug-delivery microparticles, pH sensors, and 3D microfluidic devices that we could not produce using traditional 3D printing. SEAL allows us to generate microstructures with complex geometry at high resolution, produce fully enclosed internal cavities containing a solid or liquid, and use potentially any thermoplastic material without processing additives. Putting the pieces together: One route to improving the delivery of existing drugs is by encapsulation inside a protective but slowly degrading shell. Such slow-release capsules improve drug availability in vivo, reduce side effects, and allow for more constant dose delivery. McHugh et al. leverage a number of existing fabrication techniques to make tiny (∼400-µm), hollow injectable microparticles that can be filled with fluid containing the therapeutic agent. By adjusting the degradation rate of the microparticle material (in this case, a lactic/glycolic copolymer), the cargo in the internal reservoir can be released at a desired time, ranging from a few days to 2 months.”