Bone is an important part of the human body structure and plays a vital role in human health. A microfluidic chip that can simulate the structure and function of bone will provide a platform for bone-related biomedical research. Hydroxyapatite (HA), a bioactive ceramic material, has a similar structure and composition to bone mineralization products. In this study, we used HA as a microfluidic chip component to provide a highly bionic bone environment. HA substrates with different microchannel structures were printed by using ceramic stereolithography (SLA) technology, and the minimum trench width was 50 μm. The HA substrate with microchannels was sealed by a thin polydimethylsiloxane (PDMS) layer to make a HA-PDMS microfluidic chip. Cell culture experiments demonstrated that compared with PDMS, HA was more conducive to the proliferation and osteogenic differentiation of the human foetal osteoblast cell line (hFOB). In addition, the concentration gradient of the model drug doxorubicin hydrochloride (DOX) was successfully generated on a Christmas tree structure HA-PDMS chip, and the half maximal inhibitory concentration (IC50) of DOX was determined. The findings of this study indicate that the HA-PDMS microfluidic chip has great potential in the field of high-throughput bone-related drug screening and bone-related research.

Liquid metal (LM), an emerging functional material, plays increasing roles in biomedical and healthcare areas. It has particular values in neural interfaces as it combines high conductivity, flowability, and biocompatibility properties. Neuro-electrical interfaces (NEIs) are effective tools to provide a bridge between the nervous system and the outside world. The main target of developing neural interfaces is to help disabled people repair damaged nerves and enhance human capacity above normal ability. This article systematically summarizes LM-based neural interface technologies, including neural electrodes for electrical signal acquisition and administration of electrical stimulation and nerve guidance conduits for neural connectivity and functional reconstruction. The discussion begins with an overview of the fundamental properties associated with LM materials involved in the field of neural interface applications. The fabrication methods of LM-based neuro-electrodes and conduits are then introduced, and the current development status of LM-based neuro-electrodes and conduits is elaborated. Finally, the prospects and possible challenges of LM-based neural interfaces are outlined.