Biomedical subjects

Yaokuang Chung

Publications and source records attributed to Yaokuang Chung.

2 recordsLinked to original sources

PubMed2006

A surface-modified sperm sorting device with long-term stability.

Microfluidic devices fabricated from poly (dime- thylsiloxane) (PDMS) offer the ability to improve our biological and medical capabilities. Although PDMS offers a range of intriguing benefits for biomedical applications, the intrinsically hydrophobic nature of PDMS may impede with the tremendous potential of these devices. Here, we describe a PDMS-based sperm sorting device, which has been surface-modified via graft-co-polymerization of poly(ethylene glycol) methyl ether methacrylate to create a moderately hydrophilic and non-fouling surface. This process involves the exposure of PDMS to UV/ozone, which activates the PDMS surface to bond to the substrate and, at the same time, initiates the graft-co-polymerization from the PDMS surface. In this study, we confirmed long-term stability of surface-modified PDMS for up to 56 days based on Fourier transformation infrared spectroscopy (FTIR), contact angle measurements, and protein adsorption studies. Moreover, the applicability of our method to PDMS-based sperm sorting devices was demonstrated by successfully sorting human sperm.

Cell Culture Techniques↗

PubMed2006

Microscale integrated sperm sorter.

This chapter describes the design and fabrication of a passively driven microfluidic sperm sorter using soft lithographic microfabrication techniques. This self-contained device can separate motile sperm from nonmotile sperm and other cellular debris. The sorting system is small (coin sized) and structurally simple. It comprises two inlets; two outlets; a sorting channel; and arrays of horizontally oriented reservoirs that function as passively driven, constant-flow-rate pumps. Sperm with higher motility are sorted out from the rest of the semen samples based on their ability to swim through interfaces between adjacent laminar streams into separate streamlines, whereas the nonmotile sperm and debris remain in their initial streamlines. The device, which we call a microscale integrated sperm sorter, does not rely on any external power sources or controllers and incorporates all sample loading and sorting functions necessary to prepare high-quality sperm for in vitro fertilization. This self-contained, inexpensive, and portable device may also be useful for developing convenient sperm motility assays that can be used at the point of care or at home.

Cell Separation↗