Use of atomic force microscopy for characterization of model membranes and cells

Abstract

Background: To provide a fundamental understanding of the potential and use of atomic force microscopy (AFM) in medicine and the life sciences, this work presents a thorough description of imaging and non-imaging atomic force microscopy modes for characterizing model membranes and cells at the nanoscale. Methods: The imaging and non-imaging AFM modes are described with examples in terms of the characterization of topographic, morphological, and nanomechanical sample properties. Results: AFM imaging of supported lipid bilayers (SLBs) revealed the effects of temperature and medium composition on SLB topography in the gel and fluid phases, and on the bilayer thickness. Non-imaging AFM showed the strengthening of the SLB in both phases by the ion binding process.Imaging of neuronal and neuroblastoma cells with and without treatment revealed morphological changes in shape, volume, roughness, and Feret dimension. Non-imaging AFM showed the change in cell elasticity induced by the treatment with H2O2 with and without quercetin and by the treatment with copper and myricetin. The measurements of cells elasticity revealed a reorganization of the cytoskeleton and filament structures. Conclusions: Diverse applications of imaging and non-imaging AFM can provide important information about the underlying processes in biologically relevant systems. AFM, as a complementary technique to other biomedical methods, allows screening and monitoring of physiological changes at the nanoscale.