Colloquium
of Physical and Theoretical Chemistry

Prof. Dr. Giovanni Marletta

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

Title of Lecture:

"Biomacromolecules at Nanostructured Surfaces: From a single molecule towards
a collective behavior view"

Wednesday, 22. Januar 2020, 16:15

Lecture Hall B, Arnimallee 22

Abstract

In recent years, the fact that nano-features at surfaces have a critical effect on the amount and structural state of macromolecules, and in particular biomacromolecules, “immobilized” at solid surfaces has become a widely accepted paradigm. This view, in turn, is connected to the wider idea that the state of the “confined” few layers at surfaces, no matter how thin, determine the “evolution” of complex biological processes as, for instance, extracellular matrix organization, cell seeding, or bacteria colonization.

In fact, focusing for instance on the tissue engineering framework, nanoscale patterning of specific biochemical motifs has been related to early events like cell adhesion and spreading, as well as to late processes like cytoskeletal organization and then cell differentiation, highlighting how nanostructures and nanosized biochemical machinery may interact with cells to respond to environmental stimuli.

In this largely phenomenological framework, the Physical Chemistry approach plays a fundamental role in elucidating the critical role of the organization of immobilized layers, including amount, nature of the binding and conformational states of the biomolecules “confined” at surfaces, providing the appropriate platform for the subsequent biochemical processes. Accordingly, experimental results on the strategies of driving adsorption selectivity and proper exposure of the bioactive sites of peptides and proteins, will be shortly reported, focusing examples of

(1) targeted chelation-based methodologies to anchoring well-defined amounts of oriented biomolecules [1,2],

(2)   counter-intuitive size-related protein trapping selectivity of nanowells [3],

(3)   a curvature-related “geometrical” resonance of nanostructure and biomolecules size determining their adsorption [4],

(4) a case study of stimuli-responsive system, consisting of chemisorbed short-chain thiolated peptides, which highlights the collective character of the “self-assembled” monolayer behavior [5].

It interesting to note that while the experiments [1-3] rely on a “single-molecule” view, i.e., looking at structure and behavior of the confined biomolecular layers in terms of mere sum of single-responding molecules, the experiment [4] rather highlights a view of the adsorbed layer in terms of the ensemble of the interacting macromolecules. This view of the action and properties of macromolecular-immobilized layers in terms of a “collective” behavior is, in our opinion, the key towards a novel understanding and control of the collective processes at functionalized surfaces.

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).