Low-fouling, mixed-charge poly-l-lysine polymers with anionic oligopeptide side-chains
Noemi Bellassai1, Almudena Marti, Giuseppe Spoto
1Consorzio Interuniversitario di Ricerca in Chimica dei Metalli nei Sistemi Biologici, c/o Dipartimento di Scienze Chimiche, Università degli Studi di Catania, Catania, Italy.
Journal of Materials Chemistry. B
|April 8, 2020
Summary
A novel mixed-charge polymer, poly-l-lysine grafted with anionic oligopeptides, provides excellent antifouling properties for biosensors. This surface effectively minimizes protein adsorption in complex biological samples like human plasma.
Area of Science:
- Biomaterials Science
- Surface Chemistry
- Nanotechnology
Background:
- Biosensors and biomedical devices need antifouling surfaces to prevent non-specific adhesion of proteins and cells.
- Detecting biomarkers in complex biological fluids like blood plasma requires surfaces that resist fouling.
Purpose of the Study:
- To develop a mixed-charge polymer surface with enhanced antifouling properties.
- To create a functionalized surface for improved biosensor performance in complex media.
Main Methods:
- A modified "grafting-to" method was used to couple cationic poly-l-lysine (PLL) with anionic oligopeptides (CEEEEE).
- Poly-l-lysine was modified with varying percentages of maleimide-NHS ester chains (PLL-mal(y%)).
- Surface characterization used contact angle and PM-IRRAS; antifouling properties were assessed via QCM-D and SPRI.
Main Results:
- Monolayer formation of modified PLLs was confirmed.
- PLL-mal(26%)-CEEEEE demonstrated superior antifouling performance in single-protein solutions.
- Nonspecific protein adsorption was reduced to 46 ng cm-2 in diluted human plasma.
Conclusions:
- The developed PLL-mal(26%)-CEEEEE polymer exhibits significant low-fouling activity in complex biological media.
- This new polymer offers a rapid and simple method for surface functionalization compared to traditional antifouling materials.
