Enzymes as Biodevelopers for Nano- And Micropatterned Bicomponent Biopolymer Thin Films

Abstract

The creation of nano- and micropatterned polymer films is a crucial step for innumerous applications in science and technology. However, there are several problems associated with environmental aspects concerning the polymer synthesis itself, cross-linkers to induce the patterns as well as toxic solvents used for the preparation and even more important development of the films (e.g., chlorobenzene). In this paper, we present a facile method to produce micro- and nanopatterned biopolymer thin films using enzymes as so-called biodevelopers. Instead of synthetic polymers, naturally derived ones are employed, namely, poly-3-hydroxybutyrate and a cellulose derivative, which are dissolved in a common solvent in different ratios and subjected to spin coating. Consequently, the two biopolymers undergo microphase separation and different domain sizes are formed depending on the ratio of the biopolymers. The development step proceeds via addition of the appropriate enzyme (either PHB-depolymerase or cellulase), whereas one of the two biopolymers is selectively degraded, while the other one remains on the surface. In order to highlight the enzymatic development of the films, video AFM studies have been performed in real time to image the development process in situ as well as surface plasmon resonance spectroscopy to determine the kinetics. These studies may pave the way for the use of enzymes in patterning processes, particularly for materials intended to be used in a physiological environment.

Cellulose carbamate derived cellulose thin films: preparation, characterization and blending with cellulose xanthate

“…AFM was employed to gain further information about the surface morphology and structure of the CC films. Compared to cellulose thin films from different sources like trimethylsilyl cellulose (TMSC) (Niegelhell et al 2016;Schaub et al 1993) or cellulose xanthate (CX) (Weißl et al 2018), the surface of CC thin films features more aggregates (10-13 nm) concomitant with slightly higher roughness. The AFM images (Fig.…”

“…Cellulose thin films provide a confined two-dimensional network with a well-defined surface morphology and chemistry (Kontturi et al 2006). Literature gives many examples, where thin films have been employed to study the influence of certain conditions on the behavior of cellulose and its derivatives, or to observe the interaction of cellulose with biopolymers or proteins (Ehmann et al 2015;Mohan et al 2017;Niegelhell et al 2016;Niinivaara et al 2016). In a previous work, some of us published a method for the processing of cellulose thin films based on the spin coating and following HCl vapor exposure of CX films (Weißl et al 2018).…”

Multilayer Density Analysis of Cellulose Thin Films

“…Nowadays, the observation of surfaces in real-time using fast scanning devices (one frame per second and faster) allows for visualizing dynamic biological processes at interfaces. For example, enzymatic degradation of biopolymers such as cellulose can be monitored and videos of the degradation process can be acquired (Giessibl, 2003; Jalili and Laxminarayana, 2004; Niegelhell et al, 2016).…”

“…In most cases, this information is sufficient because it allows for monitoring adsorption processes at the interfaces, in terms of deposited mass and adsorption kinetics. Many examples do exist which investigate biomolecule deposition on cellulose thin films mainly with the aim to establish sensor systems or antifouling surfaces (Orelma et al, 2011, 2012; Niegelhell et al, 2016, 2017, 2018; Strasser et al, 2016; Mohan et al, 2017; Weißl et al, 2018). Since water incorporation into the film changes its refractive index, swelling has been investigated by SPR as well for the whole film (Kontturi et al, 2013).…”

Homogeneous cellulose thin films by regeneration of cellulose xanthate: properties and characterization

“…Therefore, they have been proposed as supports for biosensors, as matrix for catalysis as well as material for optoelectronic devices such as transistors and solar cells (Blomstedt et al 2007;Filpponen et al 2012;Niegelhell et al 2016;Orelma et al 2011Orelma et al , 2012Reishofer et al 2017;Taajamaa et al 2013;Wolfberger et al 2015). Further, these films have been employed as models to investigate and to better understand interactions of water with cellulose, particularly in the context of cell wall structure and their relation to industrially applied drying processes (Ehmann et al 2015;Niinivaara et al 2015Niinivaara et al , 2016.…”