Novel molecular design of culture substrates with amino acids

Abstract

PurposeBiocompatible and bioactive substrates are important in tissue engineering. The nature of these substrates can directly influence cellular response, ultimately affecting the rate and quality of new tissue formation. A novel atomic layer deposition/molecular layer deposition (ALD/MLD) technique was used to build cell culture substrates to do a preliminary assessment of this techniques’ potential within ocular surface tissue engineering.MethodsOrganic‐inorganic hybrid substrates were prepared with ALD/MLD, which enables deposition of single molecular layers of compounds in a very controlled manner. The substrates are based on amino acids, including lysine, arginine, glycine and aspartic acid, as organic building blocks and titanium as inorganic building blocks. Human corneal epithelial cells were cultured on the substrates for 7 days. The cells were then stained with Hoechst and imaged at 5× magnification with a fluorescence microscope. The number of cell nuclei per field of view was counted to compare cell density. In parallel, cells were also stained with trypan blue to assess the number of dead cells.ResultsConfluent cultures were obtained on all substrates and most of the cells were alive. Substrates with glycine and titanium oxide yielded the highest cell density (1,031 cells ± 65), whereas substrates with aspartic acid and titanium oxide (689 cells ± 48) gave rise to the least number of cells.ConclusionsHuman corneal epithelial cells can be successfully grown on organic‐inorganic hybrid substrates while retaining high viability. The novel ALD/MLD technique can be used to build biocompatible substrates using molecular design and further studies should be conducted to evaluate if this technique can be used to direct cell and tissue development.