Surface-modified substrates for the Langmuir-Blodgett deposition of patterned ultra-thin and highly oriented collagen coatings

Abstract

As a pre-study for highly oriented collagen coatings on implants (with irregular surfaces and shapes), the Langmuir-Blodgett (LB) technology, a low-cost and straightforward approach, was pioneered. The effects of physicochemical (hydrophilic/hydrophobic) patterns and 3D-mechanical barriers present on substrate surfaces are studied in terms of the dynamics of collagen flow during LB film deposition and the formation of highly oriented coatings. Due to the large internal cohesion of collagen films, only large 3D-obstacles deflect the flow of collagen and lead to film rupture, suggesting that objects (screw-threaded dental implants) with small topographic features should be easily and evenly coatable. Moreover, hydrophilic/hydrophobic/collagen patterned substrate surfaces were fabricated, by partly removing coated collagen. These substrates are outstanding for timely studies that need identical conditions but different surface properties side by side. Crystallisation of barium oxalate was carried out as a proof-of-principle.