Polydopamine (PDA) surfaces have attracted much attention, both for their innate capability as a versatile biomaterial and their standalone antibacterial and adhesive properties. However, the mechanics of PDA deposition as well as the attributes of PDA-coated surfaces remain relatively underexplored despite their adaptability and ease of deposition. Two polydopamine surfaces from literature, smooth and rough PDA (sPDA and rPDA), were compared to a novel surface, inverted PDA (iPDA), to further explore their mechanochemical and bioactive properties. The iPDA surface displayed, by design, a smoother topography when compared to sPDA, with smaller aggregate structures covering 2.7% of the overall surface. However, the chemical signature obtained via Raman spectroscopy of these aggregates shared remarkable similarities at the 1370 cm-1 peak with the rougher rPDA surface, leading to the conclusion that gas exchange at the solution surface may play a critical role in determining PDA subunit composition despite dissimilar deposition methods. Atomic force microscopy (AFM) analysis concluded that the iPDA surface was ~17% more adhesive than other PDA types, while also displaying relatively large hysteresis and a small Young’s modulus. Human osteoblastic MG-63 cells cultured on all three surfaces revealed that a smoother surface topography correlated to more pronounced anisotropic spread independent of cell size, while a serum-independent component was also noted. This work provides a clearer insight into the nature of polydopamine surfaces by the creation of a viable new deposition method, providing an analysis of its mechanochemical and bioactive properties as well as a deeper understanding of the PDA coating process.
| Identifer | oai:union.ndltd.org:uottawa.ca/oai:ruor.uottawa.ca:10393/43300 |
| Date | 15 February 2022 |
| Creators | Spracklin, Michael |
| Contributors | Variola, Fabio |
| Publisher | Université d'Ottawa / University of Ottawa |
| Source Sets | Université d’Ottawa |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | application/pdf |
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