A simulated microgravity-oriented AIE probe-ECM hydrogel-integrated chip for cell culture and superoxide anion radical detection.

Human space activities have been continuously increasing. Astronauts experiencing spaceflight are faced with health problems caused by special space environments such as microgravity, and the investigation of cell injury is fundamental. The development of a platform capable of cell culture and injury detection is the prerequisite for the investigation. Constructing a platform suitable for special conditions in space life science research is the key issue. The ground-based investigation is an indispensable part of the research. Accordingly, a simulated microgravity (SMG)-oriented integrated chip platform capable of 3D cell culture and in situ visual detection of superoxide anion radical (O2•-) is developed. SMG can cause oxidative stress in human cells, and O2•- is one of the signaling molecules. Thus, a O2•--responsive aggregation-induced emission (AIE) probe is designed, which shows high selectivity and sensitivity to O2•-. Moreover, the probe exhibits abilities of long-term and wash-free staining to cells due to the AIE behavior, which is precious for space cell imaging. Meanwhile, a chip with a high-aspect-ratio chamber for adequate medium storage for the lack of the perfusion system during the SMG experiment and a cell culture chamber which can integrate the extracellular matrix (ECM) hydrogel for the bioinspired 3D cell culture is fabricated. In addition, a porous membrane is introduced between the chambers to prevent the hydrogel from separating during the SMG experiment. The afforded AIE probe-ECM hydrogel-integrated chip can achieve 3D culturing of U87-MG cells and in situ fluorescent detection of endogenous O2•- in the cells after long-term staining under SMG. The chip provides a powerful and potential platform for ground-based investigation in space life science and biomedical research.

Capillary-Bridge Controlled Patterning of BTR:PC71 BM Bulk Heterojunction Micro Arrays towards High-Performance Photodetector.

The patterning strategy of organic semiconductors is a crucial issue for integrated circuit. However, due to the uncontrollable liquid dewetting, most of the research is mainly focused on the patterning of single component, few works have been done on the patterning of multi-component or heterojunction, which play an important role in optoelectronic devices. Therefore, a capillary-bridge strategy was introduced for patterning of bulk heterojunction (BHJ) micro-arrays, with liquid crystalline BTR and PC71 BM utilized as donor and acceptor, respectively. The BTR:PC71 BM arrays presented hierarchical morphology with suitable phase separation, which contributes to the efficient charge generation and transport. Moreover, the photodetector exhibited excellent performance with the light on/off ratio greater than 2000, the responsivity of 40.57 A W-1 , and specific detectivity of 2.15×1012  Jones. Such progress demonstrates that the capillary-bridge strategy is a promising approach for the fabrication of high-quality BHJ micropatterns arrays.