Lubricated Interfaces Enabling Simultaneous Pulsatile and Continuous Chemical Release Modes.

The release of chemicals following either pulsatile or continuous release modes is important for various potential applications, including programmed chemical reactions, mechanical actuation and treatments of various diseases. However, the simultaneous application of both modes in a single material system has been challenging. Here, we report two chemical loading methods in a liquid crystal-infused porous surface (LCIPS) which enables both a pulsatile and continuous release of chemicals simultaneously. Specifically, chemicals loaded in the porous substrate exhibit a liquid crystal (LC) mesophase-dependent continuous release, whereas the chemicals dissolved in micrometer-sized aqueous droplets dispersed in the LC surface follow a pulsatile release activated by a phase transition. Moreover, we can control the loading method of distinct molecules to program their release mode. Finally, we demonstrate the pulsatile and continuous release of two distinct bioactive small molecules, tetracycline and dexamethasone, which display antibacterial and immunomodulatory activities for applications such as chronic wound healing and biomedical implant coating. This article is protected by copyright. All rights reserved.