2020 Smart Biopolymer‐Based Multi‐Layers Enable Consecutive Drug Release Events on Demand

Ceren Kimna, Benjamin Winkeljann, Jian Song, and Oliver Lieleg

Adv. Mater. Interfaces 2020,2000735 DOI: 10.1002/admi.202000735


Department of Mechanical Engineering and Munich
School of Bioengineering
Technical University of Munich


All implantation surgeries carry the risk of immediate or recurring infections at the surgical site. To combat this problem, employing implant coatings can be a useful strategy. A multi-layered surface coating that actively responds to two different physiological stimuli with the liberation of two independent drug doses is presented here; the first dose is supposed to overcome an immediate inflammation caused by a contamination of the surgical site whereas the second dose may treat recurring infections. To make this possible, the strategy combines thermoresponsive liposomes with sacrificial layers and a transient condensation of biopolymer layers. Moreover, when the release is completed, the remaining surface coating provides beneficial longterm properties such as improved lubricity. Due to its high specificity toward the two release triggers, its good loading capacity, and excellent release efficiency, the mechanism presented here may pave the way toward the development of a new generation of smart implant coatings that can autonomously combat two temporally separated infection events.