Construction of low-wettable free-standing layer-by-layer multilayer for fibrinogen adsorption

Abstract

With advancements in medical technology, various wound dressing materials are available for all types of wounds. As a dynamic process of wound healing, the first phase, namely “hemostasis” depending on protein adsorption, is a pivotal role for the following continuous phase. Although recent technological developments are investigating wound dressings that are degradable in vivo or thinner and less visible by fabricating a film that is free-standing from the substrate, there are few literatures which can show self-standing Layer-by-Layer (LbL) films dealing with the complex relation of mechanical property, wettability, and protein adsorption. Here, we demonstrate a wettability-controlled free-standing LbL multilayer with featuring each construction process. The successful free-standing LbL films were evaluated for efficient fibrinogen adsorption. The surface wettability was controlled by changing the number of bilayers and the annealing temperature as a process before peeled off from the substrate, and it increased from 40° to nearly 90°. The annealing time also influenced the peeling time by changing swelling and shrinkage, and the annealing at 180 °C achieved the complete exfoliation from the substrate for 10 min. The 35-bilayer free-standing film showed the maximum stress value of 29.4 MPa and the elongation property of 2.2 %. The free-standing LbL film trapped fibrinogen in the fibrinogen dispersion while the film without annealing did not show the change of peak ratio after the fibrinogen adsorbed test. The study would be valuable for manufacturing wettability-controlled free-standing films and demonstrate the possibility of future wound healing thin films.