The organ-on-a-chip (OOAC) is in the list of top 10 emerging technologies and refers to a physiological organ biomimetic system built on a microfluidic chip. Through a combination of cell biology, engineering, and biomaterial technology, the microenvironment of the chip simulates that of the organ in terms of tissue interfaces and mechanical stimulation. This reflects the structural and functional characteristics of human tissue and can predict response to an array of stimuli including drug responses and environmental effects. OOAC has broad applications in precision medicine and biological defense strategies. Here, we introduce the concepts of OOAC and review its application to the construction of physiological models, drug development, and toxicology from the perspective of different organs. We further discuss existing challenges and provide future perspectives for its application.

Cancer is one of the leading causes of mortality worldwide, because of the lack of accurate diagnostic tools for the early stages of cancer. Thus, early diagnosis, which provides important information for a timely therapy of cancer, is of great significance for controlling the development of the disease and the proliferation of cancer cells and for improving the survival rates of patients. To achieve the goals of early diagnosis and timely therapy of cancer, DNA nanotechnology may be effective, since it has emerged as a valid technique for the fabrication of various nanoscale structures and devices. The resultant DNA-based nanoscale structures and devices show extraordinary performance in cancer diagnosis, owing to their predictable secondary structures, small sizes, and high biocompatibility and programmability. In particular, the rapid development of DNA nanotechnologies, such as molecular assembly technologies, endows DNA-based nanomaterials with more functionalization and intellectualization. Here, we summarize recent progress made in the development of DNA nanotechnology for the fabrication of functional and intelligent nanomaterials and highlight the prospects of this technology in cancer diagnosis and therapy.

Surface-immobilized pure DNA hydrogels were formed using a surficial primer-induced strategy and adopted as scaffold materials for biosensing applications.