Three-Dimensional Polyglycerol-PEG-Based Hydrogels as a Universal High-Sensitivity Platform for SPR Analysis.

Area of Science:

• Biomaterials Science
• Analytical Chemistry
• Biosensing Technology

Background:

• Surface Plasmon Resonance (SPR) is a powerful label-free technique for analyzing molecular interactions.
• Current SPR biosensing matrices often face limitations in ligand immobilization capacity and nonspecific binding, particularly for small molecule analysis.
• Developing advanced matrices is crucial to enhance the sensitivity and specificity of SPR-based assays.

Purpose of the Study:

• To develop and characterize a novel three-dimensional (3D) polyglycerol-poly(ethylene glycol)-based hydrogel as a biosensing matrix for SPR.
• To evaluate the hydrogel's capacity for high ligand loading and its effectiveness in reducing nonspecific binding.
• To demonstrate the improved performance of the hydrogel matrix in affinity analysis of small molecules.

Main Methods:

• Synthesis of a 3D hydrogel by cross-linking functionalized polyglycerol with dithiolated poly(ethylene glycol) via thiol-click chemistry.
• Characterization of the hydrogel's properties, including ligand immobilization capacity and nonspecific binding.
• Performance evaluation using carbonic anhydrase II as a model ligand and acetazolamide as the analyte in SPR experiments.
• Comparison with standard (CM5) and high-capacity (CM7) commercial SPR sensor chips.

Main Results:

• The developed hydrogel matrix demonstrated a significantly higher immobilization capacity for biomolecules compared to standard SPR sensors.
• The hydrogel exhibited reduced nonspecific binding due to its non-carbohydrate structure.
• A five-fold increase in carbonic anhydrase II loading and acetazolamide binding signal was observed compared to standard CMD sensors (CM5).
• Ligand loading capacity was comparable to specialized high-loading CMD sensors (CM7).

Conclusions:

• The 3D polyglycerol-poly(ethylene glycol) hydrogel serves as an innovative and effective biosensing matrix for SPR.
• The combination of high ligand loading and reduced nonspecific binding offers a significant advantage over existing commercial SPR biosensors.
• This novel matrix holds great potential for a broad range of SPR applications, particularly in small molecule analysis and affinity screening.