Herein we report a new type of artificial cells capable of long-term protein expression and regulation. We constructed the artificial cells by grafting anti-His-tag aptamer into the polymer backbone of the hydrogel particles, and then immobilizing the His-tagged proteinaceous factors of the transcription and translation system into the hydrogel particles. Long-term protein expression for at least 16 days was achieved by continuously flowing feeding buffer through the artificial cells. The effect of various metal ions on the protein expression in the artificial cells was investigated. Utilizing the lac operator-repressor system, we could regulate the expression level of eGFP in the artificial cells by controlling the β-D-1-thiogalatopyranoside (IPTG) concentration in the feeding buffer. The artificial cells based on the aptamer grafted hydrogel provide a useful platform for gene circuit engineering, metabolic engineering, drug delivery, and biosensors.

Herein, we constructed a new type of hydrogel based artificial cells supporting long-lived protein synthesis, posttranslational modification, and gene networks. We constructed the artificial cells by immobilizing the transcription and translation system from E. coli cytoplasmic extract onto the polyacrylamide hydrogel. With the continuous supply of energy and nutrition, the artificial cells were capable of stable protein expression for at least 30 days. Functional proteins which were difficult to produce in vivo, including colicin E1 and urokinase, were synthesized in the artificial cells with high bioactivity. Furthermore, we constructed a sigma factor based genetic oscillator in the artificial cells. The artificial cells not only provide a powerful platform for continuous protein synthesis and convenient design and testing of genetic networks, but also hold great promise for the development of metabolic engineering, drug delivery, and biosensors.

A selective PCR for the enrichment of low-abundance mutations by introducing a branch migration blocker into the PCR process.

In recent years, droplet microfluidics has become an important tool for the development of precision medicine. Droplets are uniformly and efficiently produced in microfluidic devices on the scale of picoliters to nanoliters. The droplets act as individual microreactors and facilitate high throughput and quantitative analysis, thus providing an attractive platform for the analysis of biomolecules or single cells in precision medicine. In this chapter, we will review the principles and techniques of droplet microfluidics, and the important applications of droplet microfluidics for precision medicine.