New chip-based drug screening system
A new technique for accurate direct measurement of protein-to-protein interactions before and after the introduction of a drug candidate is developed using atomic force micrsocopy (AFM). An example using T-cell/CD28 immobilized on-chip and B-cell/CD80 immobilized on an AFM tip was performed and demonstrated that a drug candidate, cynarin, could block CD80 from binding with CD28 via unbinding force measurements. The average unbinding forces between CD28 and CD80 after blocking by cynarin were reduced from 61.4 pN to 38.9 pN with a blocking effect of ∼37% as compared with only ∼9% by surface plasma resonance (SPR) measurement. AFM, which can provide accurate quantitative measures, provides an attractive option as a method for drug screening. The method could be applied to a wider variety of drug candidates with advances in bio-chip technology.
Kao et al. Biotechnol Bioeng 2012;109: 2460–2467.