Talk presented by

Prof. Dr. Giovanni Marletta

Laboratory for Molecular Surfaces and Nanotechology (LAMSUN-CSI), Dept. of Chemical Sciences – University of Catania – Catania (Italy)

entitled:

"Biomacromolecules at Nanostructured Surfaces: Anchoring, Trapping and Orienting Proteins and Peptides"

Abstract

In recent years, the fact that nano-features at surfaces have a critical effect on the amount and structural state of adsorbed biomacromolecules has become a widely accepted paradigm, as much important as their state in the adsorbed layers is perceived as determining the processes of cell seeding on functionalized scaffolds and, in general, to the tissue engineering strategies. Thus, the nanoscale patterning of specific biochemical motifs, has been shown to determine the cell adhesion and spreading, as well as cell differentiation and cytoskeletal organization, suggesting a close relationship between the surface nanostructures and the nanosized biochemical machinery that allows cells to respond to environmental stimuli.

In this framework, the present lecture will discuss recent experimental results, based on techniques as quartz crystal microbalance with dissipation monitoring, nanoplasmonic sensing, time-of-flight secondary ion mass spectrometry and molecular dynamics simulations, from the group of the Laboratory for Molecular Surfaces and Nanotechnologies, pointing to the importance of driving adsorption selectivity and proper exposure of the bioactive sites of peptides and proteins. In particular, examples will be shown of targeted chelation-based methodologies to anchoring well-defined amounts of oriented biomolecules [1,2], of counter-intuitive size-related protein trapping selectivity of nanowells [3], of a curvature-related “geometrical” resonance of nanostructure and biomolecules size determining their adsorption [4].

It is interesting to note that all the mentioned experiments rely on a kind of “single-molecule-limited” view of the structure and behavior of adsorbed biomolecular layers, which, owing to the influence of the pervasive use of self-assembled monolayer-based strategies of surface functionalization, are often considered as mere assemblies of single-responding molecules. In the lecture an adjourned view is proposed of the adsorbed layer structure and behavior, as due to the whole ensemble of anchored and therefore interacting molecular systems. A case study of a stimuli-responsive system, consisting in chemisorbed short-chain thiolated peptides will be discussed, highlighting the collective character of the structure and response of the systems forming the “self-assembling” monolayer [5].

References

[1] G.M.L. Messina, et al.; Langmuir 35, 3354-3362 (2019).

[2]N. Giamblanco, et al.; ACS Appl.Mater.Interf. 7, 23353-23363 (2015).

[3] G.M.L. Messina, et al.; Nanoscale 8, 16511-16519 (2016).

[4] G.M.L. Messina, et al.; Nanoscale 10, 7544-7555 (2018).

[5] G.M.L. Messina, et al.; Langmuir 35, 4813-4824 (2019).