Effects of chitosan on cell viability and the cytoskeleton of Caco-2 cells

Abstract

Chitosan is a cationic polysaccharide obtained by partial N-deacetylation of chitin that has a number of biochemical and pharmaceutical applications. In this project, the effect of various concentrations of chitosan on cell viability has been assessed using Caco-2 cells, a well-known in vitro transport model for the intestinal epithelium, with reference to cell viability. Initially, attempts in treating Caco-2 cells with microparticles of chitosan base were carried out, and different strategies for sterilization of chitosan malate solutions of were tested. Testing of cell viability after treatment with chitosan malate solution for 24 h were performed using the MTT assay. To assess a possible recovery from the cell damage induced by chitosan malate, recovery experiments were performed, letting the cells recover under normal cultivation conditions for 24 h. As chitosan malate is acidic, and low pH values can affect cell viability, control experiments were performed to rule out low pH as the determining factor of reduced cell viability after chitosan malate treatment. Cell viability testing was also carried out using chitosan malate microparticles.

The cell cytoskeleton has an important role in determining cell shape and in many cellular processes such as motion, division and intracellular transport and consists of three main kinds of filaments; microtubules, actin filaments and intermediate filaments. The effect of chitosan malate on two of the main components of the cytoskeleton, microtubules and microfilaments, of Caco-2 cells has been investigated using immunofluorescence techniques. To assess the potential recovery from chitosan induced rearrangement of cytoskeletal filaments, recovery experiments were carried out letting the cells recover for 24 h.

This study showed that chitosan malate affects the cell viability of Caco-2 cells in a dose-dependent manner. Recovery from the cell damage does not seem to take place to an extent detectable by the method used.

Chitosan malate induced redistribution of the cytoskeletal proteins, tubulin and actin, also in a dose-dependent manner. Partial recovery of the cytoskeletal rearrangement was seen after 24 h after terminated treatment.