Surface interactions controllable with functionalization of thin films attract much attention and are used as coatings in several industries, from electronics to biomedical applications. Model films offer a direct control of several parameters, such as film thickness and surface morphology, and offer many advantages compared to bulk samples . Chitosan model films, to be more specific, could be a potentially great outlet for many surface reactions, because of its amino functional group presence. The surface chemistry of chitosan films could be modified by biofunctionalization involving immobilization of proteins, peptides, as well as glycoconjugates . Herein, we want to develop a concise protocol for on surface immobilization of glycopeptides with a desired amino acid sequence.
A spin coating deposition method for uniform thin films of chitosan onto a solid substrate is applied. Surface changes are analyzed at each step of the experiment with different characterization methods such as profilometry measurements for film thickness, wettability determination by water contact angle, and surface morphology analysis with atomic force microscopy (AFM). Furthermore, elemental composition, as well as chemical state, is determined with x-ray photoelectron spectroscopy (XPS) which aligned, with our assumptions perfectly. Biofunctionalization of the prepared film surface is observed with an in-situ quartz crystal microbalance with dissipation measurement (QCM-D), where depositions as small as 17,7 ng/cm2 can be detected. Biofunctionalization is carried out with standard N-tertbutyloxycarbonyl (Boc) protected glycine as model substrate (Figure 1). Moving forward, biofunctionalization of chitosan surface with synthesized glycoconjugates , composed of a carbohydrate glycon and a lysine residue via an Amadori Rearrangement, is performed. Coupling with the film surface is detected with QCM-D as frequency decrease or mass gain on the quartz gold crystal. Results and experimental details will be presented.
|Period||12 Oct 2021|
|Event title||7th EPNOE International Polysaccharide Conference|
|Degree of Recognition||International|