Invited Paper TF-MoA8
ALD-based Functionalization of Biomaterials: Recent Developments and Future Challenges

Monday, October 30, 2017, 4:00 pm, Room 20

Biomaterials are engineered to interact with biological systems for therapeutic and diagnostic clinical applications. Biomaterials can be synthesized in a lab or can directly be obtained from natural resources, and they constitute whole or part of a biomedical device or a living structure that can be utilized to execute, improve, enhance or restore a natural function. The surface of a biomaterial controls the interactions occurring at the interface between the biomaterial surface and its surrounding living environment. Hence, successful performance of a biomaterial relies on its appropriate surface properties. Many biomaterials do not have appropriate surface functions and properties to cater to specific needs and applications. Therefore, surface modification and functionalization leading to significantly improved performance of biomaterials would be highly desirable and sought after.

In modern surface science and engineering, bio-nanotechnology is a potent tool to functionalize surfaces incorporating nanometer size thin films and nano-structural features into materials. Among the available deposition techniques, atomic layer deposition (ALD) offers unique advantages in yielding conformal thin films of metal oxides or metals (from a few Å to hundreds of nm thick), uniformly, with precise control at atomic or molecular level; in this manner, the performance and functionality of functionalized biomaterials could be selectively altered, optimized and controlled as needed.

ALD is a relatively new technique for optimizing materials in bio-nanotechnology. Here, after a brief review of the more widely used modes of ALD, ALD’s potential in bio-nanotechnology is presented with a few of its latest developments in biotechnology. ALD is promising means in tuning the hydrophilicity/hydrophobicity characteristics of biomedical surfaces, forming conformal ultra-thin coatings with desirable properties on high aspect ratio biomedical substrates, tuning the anti-bacterial properties of substrates surfaces of interest, and yielding multifunctional biomaterials for medical implants and other devices.

Recent developments on ALD at low (room or near room) temperature to functionalize the surface of heat-sensitive biomaterials with complex nanostructures are presented and discussed. Surface characterizations are done to investigate the morphology, chemical composition, crystallinity and wetting behavior of ALD-nanofilm coated biomaterial surfaces. The bioactivity of ALD TiO₂-coated surfaces, for example, is presented using in-vitro and in-vivo biocompatibility and biomineralization studies. Future challenges of ALD-based functionalization of biomaterials will be discussed.