A Novel System for Fabricating Microspheres with Microelectromechanical System-Based Bioprinting Technology.

The microspheres were widely utilized in the field of life sciences, and we have developed an innovative microelectromechanical system (MEMS)-based bioprinting technology (MBT) system for the preparation of the microspheres. The microspheres can be automatically and high-throughput produced with this cutting-edge system. This paper mainly introduced a novel, efficient, and cost-effective approach for the microsphere fabrication with the MBT system. In this work, the whole microsphere production equipment was built and the optimal conditions (like concentration, drying temperature, frequency, and voltage) for generating uniform hydroxypropyl cellulose-cyclosporine A (HPC-CsA) and poly-l-lactic acid (PLLA) microspheres were explored. Results demonstrated that the optimal uniformity of HPC-CsA microspheres was achieved at 2% (w/v) HPC-CsA mixture, 45 °C (drying temperature), 1,000 Hz (frequency), and 25 V (voltage amplitude). CsA microspheres [coefficient of variation (CV): ~9%] are successfully synthesized, and the drug encapsulation rate was 84.8%. The methodology was further used to produce PLLA microspheres with a diameter of ~2.55 μm, and the best CV value achieved 6.84%. This investigation fully highlighted the integration of MEMS and bioprinting as a promising tool for the microsphere fabrication, and this MBT system had huge potential applications in pharmaceutical formulations and medical aesthetics.