Monitoring of Binding Affinity Between Drugs and Human Serum Albumin Using Reflectometric Interference Spectroscopy with Silica Colloidal Crystal Films

The monitoring of binding affinity between human serum albumin and drugs with reflectometric interference method based on silica colloidal crystal films was done. Silica colloidal crystal films were fabricated using the vertical evaporation method. HSA was immobilized covalently on SCC film and optical thickness was used as a parameter to evaluate the process of drug absorption and desorption. This method describes the reversible binding event with HSA immobilized, drugs adsorption, and desorption stages real time. When a drug enters an organism, interactions between the drug and proteins in the organism play a vital role in the storage, transport and metabolism of the drug and also affect its nonspecific toxicity, targeting and pharmacodynamic activity. However, monitoring the interaction process is a great challenge in the research of the absorption, transport and metabolic processes of drugs. In this study, we used reflectometric interference spectroscopy (RIfS) and silica colloidal crystal (SCC) film as a sensing platform to detect the binding affinity between human serum albumin (HSA) and indomethacin. SCC films composed of three silica nanospheres with different diameters were fabricated using the vertical evaporation method. HSA was immobilized covalently on SCC film using a very simple approach, and optical thickness was used as a parameter to evaluate the process of drug absorption and desorption. Finally, the optimal SCC film was selected, and three drugs other than indomethacin (i.e., warfarin, salicylic acid and quinine) were used for the validation of this sensing platform. The results verified that SCC film using RIfS is a simple and real-time sensing platform for detecting the affinity between HSA and drugs, which may be widely used in drug development and clinical testing in the future.

Automated summary

The study used vertical evaporation method to fabricate silica colloidal crystal films and utilized reflectometric interference spectroscopy to detect the binding affinity between human serum albumin and drugs. The results demonstrated that this simple real-time sensing platform can effectively monitor the processes of drug absorption and desorption.