A major breakthrough in targeting intracellular drug delivery has been made by the laboratory of Micro/Nano Electromechanical System (M/NEMS) in the School of Precision Instruments and Optoelectronics Engineering at Tianjin University.

The team proposed, for the first time, a novel chemical-free cell poration method, called 'hypersonic poration', which can operate on cells using hypersonic waves generated by a piezoelectric nano-electromechanical resonators to improve cellular uptake especially nucleus uptake. This technology has realized the precise delivery of many biomolecules, which provides a new platform for targeted and localized intracellular drug delivery and also broadened the applications of the MEMS technique in biological science. Related results have been recently published on-line in ‘Small', an international authoritative journal in the area of Micro/Nano technology.

Precise and effective intracellular delivery of exogenous molecules such as target drug molecules, therapeutic genes and proteins is a major technology in modern scientific studies of precision medicine and cell biology. Traditional intracellular delivery approaches, such as chemotherapy, are mostly based on chemical or electrical stimulus which cannot provide selective delivery and may induce an immune response, thus damaging normal cells and resulting in side effects. Since MEMS resonators have the advantage of miniaturization and low power consumption, they can be implanted into human bodies and thus realize selective and localized intracellular delivery. Moreover, single cell drug delivery based on Micro/Nano technology has become a hotspot in the study of modern molecular biology.

MEMS refers to micro electromechanical systems composed of moveable elements with sizes of 0.5~500 micrometers. Under the leadership of Professor Pang Wei and the joint efforts of Professor Duan Xuexin, Wang Yanyan and other team members, research on MEMS resonators, sensors and actuators wwas carried out in MEMS groups and have been extended to the area of biological science. The team has also acquired many high level scientific achievements with proprietary intellectual property rights.

The technology of ‘hypersonic poration’ is based on hypersound generated by MEMS acoustic resonators. The hypersound has a typical frequency larger than GHz, which can effectively form reversible temporal nanopores in cells, improve membrane permeability and lead to intracellular delivery enhancement of exogenous materials such as target drugs and genes. Compared with ultrasound, hypersound will have stronger interactions with cells (60 times higher according to theory analysis) and directly induce normal/shear stress and 'molecular bombardment' effects on bilayer membranes. Thus, controllable and precise delivery of materials into cells, especially into cell nucleus can be achieved with minimal toxic and side effects occurring in cells.