PHYSICAL CHEMISTRY OF BIOINTERFACES

The course aims to provide insights into the chemical and physical concepts already covered in other disciplines of the B.D. and M.D. courses, such as physics of biological systems, chemistry, organic chemistry, biochemistry. The course contents relate to the basic principles and properties of surfaces and solid-liquid interface. Specific goals of this course are: to provide the tools necessary to the understanding of the various types of interactions that take place between cells and tissues and their natural or artificial environment, thermodynamic and kinetic aspects of protein-biomaterial interface, with emphasis on the fundamental role of water at the biointerfaces. Another training objective of the course is to explain how cellular processes such as adhesion, differentiation and proliferation may be influenced by mechanical (viscoelasticity), physical (topography) and chemical (surface free energy, composition and structure) properties of the surfaces and how these can be modulated through the surface tailoring, even on the nanometer scale, and / or the change of the environmental conditions (chemical stimulus, physical and / or biological). In the laboratory the student will take awareness not only of the fundamental role carried out by this discipline in various scientific and technological fields (of drug transport and release, biosensors, imaging), but also will make practice with processes of chemical synthesis of nanoparticles and spectroscopic and microscopic characterization techniques of biointerfaces.

Furthermore, in reference to the so-called Dublin Descriptors, this course helps to acquire the following transversal skills:

• Knowledge and understanding: getting to know the essential characteristics of biointerfaces and be able to solve, both qualitatively and quantitatively, simple problems about the biomolecule-material interaction.
• Applying knowledge and understanding: application of the acquired theoretical knowledge for the comparison of experimental results with those of calculation, relative to case studies of biointerfaces between cells and the extracellular matrix (ECM) and between cells, ECM and medical devices.
• Making judgments: gathering and interpreting relevant data, critical reasoning skills, ability to identify the predictions of a theory or a model.
• Communication skills: ability to describe a scientific topic in oral form, with properties of language and terminological rigor, explaining the reasons and results.
• Learning skills: to have developed the necessary skills to undertake subsequent studies with a high degree of autonomy.

Frontal lessons delivered in the classroom with the aid of the blackboard and suitable projection of slides. Classroom solution of problems and answers to exercises relevant to the main topics of the course. The participation of the students in the laboratory experiences and in related introductory lessons is mandatory. In the laboratory, there are working places with suitable equipment to perform the considered experiences; students will work in group. The results of each laboratory experience must be accurately reported by each student in their laboratory notebook.The aim of the writing of this notebook is a self-assessment by the student of the degree of understanding of the experimental activities and the ability to describe them in a scientific and reproducible way.

Physical chemistry of interfaces. Introduction to the concept of biointerface. Definitions and properties of surfaces. Nano-bio-interfaces.

Theoretical and applied aspects of biointerfaces. Biomaterials. Biosensors. Bioelectronics. Tissue engineering. Nanomedicine and theranostics.

Intermolecular forces and self-assembling processes. Structural aspects of dry and wet surfaces (double layer), energy aspects (interface energies, superhydrophobicity). Charged surface and colloid surface chemistry. Elasticity and viscoelasticity of biomolecular systems. Case studies of biomolecular self-assembling systems.

Biomaterials. Preparation of biomaterials and biomedical implants; physico-chemical characterization of their surface properties. The reaction of the outer body and encapsulation system.

Microfabrication and nanofabrication applied to biointerfaces. Structuring of surfaces; Molecular imprinting; self-assembling monolayers; techniques of micro- and nanomaterials synthesis. Influence of topography, mechanical properties and chemical groups on the cellular response.

Examples of biological characterization of surfaces and interfaces. Supported lipid bilayer membranes (SLB). Comparison between acoustic (quartz crystal microbalance with dissipation monitoring, QCM-D), optical (surface plasmon resonance SPR; oprical waveguide light spectroscopy, OWLS) and microscopic (atomic force microscopy, AFM; laser scanning confocal microscopy, LSM) techniques

Biointerfaces at the nanoscale. Interaction between cells and their biological environment, cell-cell and cell-extracellular matrix (ECM) interaction. Adsorption of proteins from a biological medium. Interaction between proteins and a solid surface. The role of water in the biomolecule adsorption onto a solid surface. The 'Goldilocks' surface. Effects of protein surface concentration, kinetics and conformation on cell behavior.

Laboratory exercises on model biointerface systems of interest in drug delivery, biosensors and imaging.

1. Handouts and lecture slides provided by the teacher

2. P. W. Atkins, J. de Paula- Chimica fisica biologica - Zanichelli

3. W. Pauli - Physical Chemistry in the Service of Medicine - Wiley &Sons

4. Wiley Interdisciplinary Reviews: Nanomedicine and Nanobiotechnology - John Wiley & Sons

5. H. Ohshima - Biophysical Chemistry of Biointerfaces - Wiley

6. B.D. Ratner, A.S. Hoffman - BIOMATERIALS SCIENCE: An Introduction to Materials in Medicine - Elsevier

7. NANOMATERIALS INTERFACES IN BIOLOGY - METHODS AND PROTOCOLS, Editors: Bergese, Paolo, Hamad-Schifferli, Kimberly (Eds.) SPRINGER