Dr. Samuele Tosatti -    samuele.tosatti@susos.com

CEO at SuSoS

Abstract: 

The development of devices for Life Science applications generally requires meticulous surface modifications and usually entails attention to non-specific and specific interactions between the surface of the device and the medium this is operating. If in most of the cases when considering micro-fluidics device one think abouts wettability and prevention of bubble formations, there are specific applications that require a precise distinguishment between the two interactions mentioned above.

Although the suppression of non-specific interaction is well-documented, the simultaneous maximization of specific interactions remains a challenge. For almost 20 years we have been active in the field of MedTech and life-science with our thin-film-based technologies. Some of these are well-known and established in the research and academic field, such as the PLLg-PEG with more than 700 papers worldwide; other technologies are more industrially  focused, such as our AziGrip4™ adhesion promoters.

More recently we have been working with our latest PAcrAm™ polymers in combination with poly-oxazolines. Beside purely non-biofunctionalized version of the surface-active polymer, used to generate long-term stable non-fouling/protein resistant coatings, we were able to synthesize two new types of azide-functionalized polymers that can be used as side chain in a comb-like polymer architecture. Beside “simple” A-PMOXA-B bi-functional polymers, we have been working with co-polymers where two monomers (functionalized and not) can be co-polymerized in the chain, increasing the number of azides per sidechain.

This allows to generate bio-functional coatings for cell adhesion or bio-sensing applications with higher total density of binding sites per unit area (2.5-DIM) thanks to binding protocol based on SPAAC Click-chemistry.

For Life Science applications, it is important to study for each sensing application the relationship between surface density of functional groups, size of the targeted group “to be bound” and the resulting interaction capabilities. Indeed, it appears that a 2D-surface is more indicated for large entities such as antibodies, while a 2.5-D surface gives its best with smaller molecules, such as short oligo sequences, peptides or similar. The comparative examples provided is aimed at helping future scientists to select in advance what kind of coating is to be tested in first instance when developing a novel (active) surface in the field of micro-fluidics and in Life Science in general.