Cells secrete substances that are essential to the understanding of numerous immunological phenomena and are extensively used in clinical diagnoses. Countless techniques for screening of biomarker secretion in living cells have generated valuable information on cell function and physiology, but low volume and real‐time analysis is a bottleneck for a range of approaches. Here, a simple, highly sensitive assay using a high‐throughput micropillar and microwell array chip (MIMIC) platform is presented for monitoring of biomarkers secreted by cancer cells. The sensing element is a micropillar array that uses the enzyme‐linked immunosorbent assay (ELISA) mechanism to detect captured biomolecules. When integrated with a microwell array where few cells are localized, interleukin 8 (IL‐8) secretion can be monitored with nanoliter volume using multiple micropillar arrays. The trend of cell secretions measured using MIMICs matches the results from conventional ELISA well while it requires orders of magnitude less cells and volumes. Moreover, the proposed MIMIC is examined to be used as a drug screening platform by delivering drugs using micropillar arrays in combination with a microfluidic system and then detecting biomolecules from cells as exposed to drugs.

The insulin-like growth factors (IGFs), IGF-I and IGF-II, are essential for regulating cell growth, differentiation and metastasis of a broad range of malignancies. The IGF-I/II actions are mediated through the IGF receptor type 1 (IGF-1R) and the insulin receptor (IR), which are overexpressed in multiple types of tumors. Here, we have firstly identified a human engineered antibody domain (eAd) from a phage-displayed VH library. The eAd suppressed the signal transduction of IGF-1R mediated by exogenous IGF-I or IGF-II in breast cancer cell lines through neutralizing both IGF-I and IGF-II. It also significantly inhibited the growth of breast cancer cells. Therefore, the anti-IGF-I/II eAd offers an alternative approach to target both the IGF-1R signaling pathways through the inhibition of IGF-I/II.

In article number https://doi.org/10.1002/smll.201900300, Junmin Lee, Ali Khademhosseini, and co‐workers develop a nanoliter and high‐throughput drug screening platform based on the combination of microwell arrays as a cell culture substrate, and micropillar arrays for drug delivery and biomolecular detection in response to drugs. The developed platform requires only a small amount of sample volume from a few cells and demonstrates increasing control and throughput while allowing direct and real‐time on‐chip measurements. It is expected to aid in improving drug screening on patient biopsies from solid tumors to realize personalized cancer therapy.