Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849, United States.
Anal Chem. 2011 Sep 15;83(18):7166-72. doi: 10.1021/ac201598b. Epub 2011 Aug 16.
A passively operated polydimethylsiloxane (PDMS) microfluidic device was designed for sampling of hormone secretions from eight individual murine pancreatic islets in parallel. Flow control was achieved using a single hand-held syringe and by exploiting inherent fluidic resistances of the microchannels (R(sampling) = 700 ± 20 kPa s mm(-3) at 37 °C). Basal (3 mM) or stimulatory (11 mM) glucose levels were applied to islets, with stimulation timing (t(stim)) minimized to 15 ± 2 s using modified reservoirs. Using enzyme-linked immunosorbent assays (ELISA) for postsampling analyses, we measured statistically equal levels of 1 h insulin secretion (1.26 ± 0.26 and 6.55 ± 1.00 pg islet(-1) min(-1), basal and stimulated; 62 islets) compared to standard, bulk sampling methods (1.01 ± 0.224 and 6.04 ± 1.53 pg islet(-1) min(-1), basal and stimulated; 200 islets). Importantly, the microfluidic platform revealed novel information on single-islet variability. Islet volume measurements with confocal reflectance microscopy revealed that insulin secretion had only limited correlation to islet volume, suggesting a more significant role for cellular architecture and paracrine signaling within the tissue. Compared to other methods using syringe pumps or electroosmotic flow control, this approach provides significant advantages in ease-of-use and device disposability, easing the burden on nonexperts.
一种被动式聚二甲基硅氧烷（PDMS）微流控装置被设计用于并行从八个单个的鼠胰岛中采样激素分泌。通过使用单个手动注射器和利用微通道的固有流阻（在 37°C 下为 700±20 kPa s mm(-3)）来实现流量控制。将基础（3mM）或刺激（11mM）葡萄糖水平施加到胰岛，通过修改储液器将刺激时间（t(stim)）最小化至 15±2s。使用酶联免疫吸附测定（ELISA）进行采样后的分析，我们测量到在统计学上与标准的、批量采样方法相比，1 小时胰岛素分泌水平相等（基础和刺激时分别为 1.26±0.26 和 6.55±1.00 pg 胰岛(-1) min(-1)，62 个胰岛）。重要的是，微流控平台揭示了单个胰岛变异性的新信息。通过共聚焦反射显微镜测量胰岛体积发现，胰岛素分泌与胰岛体积只有有限的相关性，这表明细胞结构和组织内旁分泌信号在其中起着更重要的作用。与使用注射器泵或电渗流控制的其他方法相比，这种方法在易用性和设备一次性使用方面具有显著优势，减轻了非专业人员的负担。
