Use microfluidic chips to study the effects of ultraviolet lights on human fibroblasts

摘要

The ultraviolet (UV) radiation from sunlight exposure is highly related to skin damages such as photoaging and skin cancers. UVA radiation can cause altered expression of extracellular matrix proteins, and UVB is believed to be an apoptosis induction factor. In the past, many experiments have been conducted in vitro to investigate how UV lights are responsible for cell damages. However, most of these studies were done under static conditions such as culture dishes, which were quite different from the in vivo dynamic circulatory system. Also, in these studies, only one UV dose was applied at one time, limiting the experimental throughput. To best mimic the physiological condition as well as to increase the throughput, a microfluidic chip was designed and fabricated to create five different UV doses in one single experimental run. This biocompatible chip is used for seeding and culturing cells, together with observing cell morphology in a circulating condition. By using the "Christmas tree" structure, five different concentrations of blue dye solutions were generated within a microfluidic chip. And by illuminating this chip with the UV light, five different UV doses could be attained on cells cultured within this chip. The effects of UVB dose on NIH/3T3 fibroblasts, mainly in terms of morphology and fluorescence-based cell damage rate, were studied.