Besides structural and physico-chemical composition, topography, roughness, adhesiveness as well as mechanical properties of biomaterials are relevant factors making them suitable for biomedical applications. All these factors affect cell differentiation and tissue formation, and are crucial for their integration as well as healing capacity in the human body. Atomic Force Microscopy is suitable for measuring all of these characteristics with nanometer scale resolution under physiological conditions. We have developed a multipurpose AFM device allowing comprehensive characterization of biological samples such as live cells, tissues and biomaterials in the nanoscale. True optical integration allows the simultaneous use of advanced inverted optical microscope techniques such as DIC or confocal laser scanning microscopy, but also upright optics, such as macroscopes for the investigation of opaque samples.
With our “Quantitative Imaging” (QI™) mode several sample properties, such as the topography, stiffness and adhesiveness, can be obtained with one measurement in high resolution. Even more complex data like Young´s modulus images, topography at different indentation forces in terms of tomography, or recognition events can be obtained. A variety of biological samples have been investigated to demonstrate the capability and flexibility of QI™. The NanoWizard® ULTRA Speed technique allows fast AFM imaging of dynamic processes with approximately 1 frame per second. The kinetics of collagen type I fibrillogenesis was imaged in situ with high spatiotemporal resolution, revealing the formation of the 67 nm D-banding hallmark. With the CellHesion® technique, the adhesion of a single living cell to any substrate can be measured and validated using comprehensive analysis tools. The Side-view cantilever holder enables a side view of the cell-sample interface while performing adhesion experiments, providing complementary information without expensive z-stacking.
The inherent drawbacks of traditional AFM imaging modes for fast imaging or for challenging samples like living cells can be overcome by the NanoWizard® ULTRA Speed and QI™ mode. We present an enhancement of AFM technique providing a versatile tool for an extensive characterization of biomaterials.