Huang Wanfeng, Chang Chun-Li, Brault Norman D, Gur Onur, Wang Zhe, Jalal Shadia I, Low Philip S, Ratliff Timothy L, Pili Roberto, Savran Cagri A
School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907, USA.
Department of Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
Lab Chip. 2017 Jan 31;17(3):415-428. doi: 10.1039/c6lc01279e.
Current efforts for the detection of prostate cancer using only prostate specific antigen are not ideal and indicate a need to develop new assays - using multiple targets - that can more accurately stratify disease states. We previously introduced a device capable of the concurrent detection of cellular and molecular markers from a single sample fluid. Here, an improved design, which achieves affinity as well as size-based separation of captured targets using antibody-conjugated magnetic beads and a silicon chip containing micro-apertures, is presented. Upon injection of the sample, the integration of magnetic attraction with the micro-aperture chip permits larger cell-bead complexes to be isolated in an upper chamber with the smaller protein-bead complexes and remaining beads passing through the micro-apertures into the lower chamber. This enhances captured cell purity for on chip quantification, allows the separate retrieval of captured cells and proteins for downstream analysis, and enables higher bead concentrations for improved multiplexed ligand targeting. Using LNCaP cells and prostate specific membrane antigen (PSMA) to model prostate cancer, the device was able to detect 34 pM of spiked PSMA and achieve a cell capture efficiency of 93% from culture media. LNCaP cells and PSMA were then spiked into diluted healthy human blood to mimic a cancer patient. The device enabled the detection of spiked PSMA (relative to endogenous PSMA) while recovering 85-90% of LNCaP cells which illustrated the potential of new assays for the diagnosis of prostate cancer.
目前仅使用前列腺特异性抗原检测前列腺癌的方法并不理想，这表明需要开发新的检测方法——使用多个靶点——以便更准确地对疾病状态进行分层。我们之前推出了一种能够从单一样本流体中同时检测细胞和分子标志物的设备。在此，我们展示了一种改进设计，该设计使用抗体偶联磁珠和包含微孔的硅芯片实现了对捕获靶点的亲和力以及基于大小的分离。注入样本后，磁吸引力与微孔芯片相结合，使较大的细胞 - 磁珠复合物在上部腔室中被分离出来，较小的蛋白质 - 磁珠复合物和剩余磁珠则通过微孔进入下部腔室。这提高了芯片上定量检测时捕获细胞的纯度，允许分别回收捕获的细胞和蛋白质用于下游分析，并能实现更高的磁珠浓度以改进多重配体靶向。使用LNCaP细胞和前列腺特异性膜抗原（PSMA）对前列腺癌进行建模，该设备能够检测到34 pM的添加PSMA，并从培养基中实现93%的细胞捕获效率。然后将LNCaP细胞和PSMA添加到稀释的健康人血液中以模拟癌症患者。该设备能够检测到添加的PSMA（相对于内源性PSMA），同时回收85 - 90%的LNCaP细胞，这说明了新检测方法在前列腺癌诊断中的潜力。
