Molecular layer deposition builds biocompatible substrates for epithelial cells

The demand for novel biocompatible materials as surface coating in the field of regenerative medicine is high. We explored molecular layer deposition (MLD) technique for building surface coatings and introduced a new group of substrates consisting of amino acids, or nucleobases, and the biocompatible metal titanium. The substrates were built from titanium tetraisopropoxide (TTIP) with l-lysine, glycine, l-aspartic acid, l-arginine, thymine, uracil, and adenine. Substrates based on zirconium chloride and terephthalic acid were also included. Titanium oxide (TiO₂ ) substrates made by atomic layer deposition and uncoated cover slips served as controls. Rat conjunctival epithelial goblet cells were grown in RPMI 1640 and RT-PCR, immunofluorescence, cell attachment, proliferation, and viability were analyzed. Cells cultured on MLD and uncoated substrates were proliferating (positive for Ki67). Cell attachment after 3 h of culture on MLD substrates was similar to uncoated coverslips (p > 0.05). Compared to uncoated coverslips, cell proliferation assayed with alamarBlue® after 4 days was significantly higher on all MLD substrates (p < 0.05), whereas terephthalic acid-containing MLD substrates reduced proliferation (p < 0.01). Viability assessed by LIVE/DEAD® was high (>85%) for all substrates after 5 days. The novel MLD technique is promising for building biocompatible substrates that direct epithelial cell growth. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 3090-3098, 2018.