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Temperature-Controlled Adhesion to Carbohydrate Functionalized Microgel Films: An E. coli and Lectin Binding Study.
Tanja J Paul1, Alexander K Strzelczyk1, Stephan Schmidt1
1Institute of Organic and Macromolecular Chemistry, Heinrich-Heine-University Düsseldorf, Universitätsstraße 1, Düsseldorf, 40225, Germany.
Macromolecular Bioscience
|February 19, 2021
Summary
Thermoresponsive poly(N-isopropylacrylamide) microgels functionalized with mannose exhibit temperature-dependent binding. Binding of concanavalin A (ConA) and E. coli varies with temperature, influenced by receptor size and microgel swelling.
Area of Science:
- Biomaterials Science
- Surface Chemistry
- Microfluidics
Background:
- Poly(N-isopropylacrylamide) (PNIPAM) microgels display thermoresponsive behavior, undergoing a phase transition at their lower critical solution temperature (LCST).
- Mannose functionalization on microgel surfaces creates specific binding sites for lectins like concanavalin A (ConA).
- Understanding the influence of temperature on molecular interactions at the microgel interface is crucial for developing smart materials.
Purpose of the Study:
- To prepare and characterize thermoresponsive mannose-functionalized PNIPAM microgel monolayers.
- To investigate the specific binding of concanavalin A (ConA) and E. coli to these microgels above and below the LCST.
- To elucidate the impact of temperature-induced microgel swelling/collapse on binding kinetics and affinity.
Main Methods:
- Preparation of mannose-functionalized PNIPAM microgel monolayers.
- Conducting inhibition and direct binding assays at controlled temperatures.
- Analyzing binding dynamics and affinity using techniques sensitive to surface interactions.
Main Results:
- Concanavalin A (ConA) binding is time-dependent, initially stronger above the LCST, but increasing below the LCST with longer incubation due to enhanced diffusion and multivalent interactions in the swollen network.
- E. coli binding is consistently enhanced above the LCST due to increased mannose density on the collapsed microgel layer.
- E. coli, once bound above the LCST, remains bound even upon cooling below the LCST.
Conclusions:
- Thermoresponsive mannose-functionalized microgel layers facilitate specific molecular binding.
- The temperature-dependent transition between swollen and collapsed microgel states modulates binding affinity based on receptor size.
- These findings highlight the potential of stimuli-responsive materials for controlled capture and release applications.
