Chitosan is a biocompatible polysaccharide of natural origin and has been the subject of interest for its use as a polymeric drug carrier materials in mucosal vaccination. Derivates of this biopolymer are regarded as being usable due to their biocompatibility, biodegradability, and absence of toxicity. As derivatives, trimethylated chitosan (TMC) and 6-O-carboxymethyl-N,N,N-trimethylchitosan (CM-TMC) polymers demonstrated beneficial water-solubility at physiological pH value. They also feature adjuvant properties by acting as permeation enhancers, transiently opening intercellular tight junctions. Thereby these polymers enable paracellular transport of drugs, which can be useful for the formulation of mucosal vaccines. Calu-3 cell monolayers are a valuable model for predicting paracellular transport kinetics in airway epithelia. Accordingly, the polymers will be tested in Calu-3 cells to study the contribution of these derivates on drug delivery at the respiratory epithelium.