Taking nanomedicine teaching into practice with atomic force microscopy and force spectroscopy

Abstract

Atomic force microscopy (AFM) is a useful and powerful tool to study molecular interactions applied to nanomedicine. The aim of the present study was to implement a hands-on atomic AFM course for graduated biosciences and medical students. The course comprises two distinct practical sessions, where students get in touch with the use of an atomic force microscope by performing AFM scanning images of human blood cells and force spectroscopy measurements of the fibrinogen-platelet interaction. Since the beginning of this course, in 2008, the overall rating by the students was 4.7 (out of 5), meaning a good to excellent evaluation. Students were very enthusiastic and produced high-quality AFM images and force spectroscopy data. The implementation of the hands-on AFM course was a success, giving to the students the opportunity of contact with a technique that has a wide variety of applications on the nanomedicine field. In the near future, nanomedicine will have remarkable implications in medicine regarding the definition, diagnosis, and treatment of different diseases. AFM enables students to observe single molecule interactions, enabling the understanding of molecular mechanisms of different physiological and pathological processes at the nanoscale level. Therefore, the introduction of nanomedicine courses in bioscience and medical school curricula is essential.

Tracking cancer In vivo imaging techniques

“…The possibility of modifying the surface and manipulating individual molecules made AFM an ideal tool for biological and biomedical applications . 5 Imaging AFM has been applied on the characterization of nanometric features at the surfaces of the samples and also on the mapping of the spatial distribution of their physicochemical properties . These equipments have Figure 4.1 Schematic illustration of the imaging mode using a sample scanner AFM: A laser beam is reflected from the cantilever, the interaction forces of the tip with the piezo-positioned samples are deflected and the adjustment mirror directs the signaling for a segmented photodetector.…”

“…30 These methodologies can be applied to blood cells, such as human erythrocytes and platelets from patients or healthy donors . 2,5,8 They are also used for imaging of cancer cells, including lymphoma Raji cells 31 and human lung adenocarcinoma cells 32 and, recently, neuronal cells from mice with chronic epilepsy . 33 Other typical applications can be found for biomolecules, such as proteins (e .…”

“…It is seldom used to quantify the interaction between the tip and a specific spot of the sample . 5,13,17 The interaction force depends on the nature of the sample, the probe tip, and the distance between them . The force-distance curve depends on these characteristics and of the medium composition, and there are obvious differences between curves obtained in air and in liquid medium .…”

“…It has been applied to structural and functional studies of dynamic processes in biological systems . [1][2][3][4] AFM has contributed significantly to the nanotechnology field, with developments in nanodiagnostic and therapeutics, contributing to the improvement of the state of the art in health care, 5 pathology, 6,7 identification of biomolecules 8 and cellular microenvironments, physiology and functions of living cells and organisms, 9 understanding of the structure-function relationship of DNA, 10 cell and molecular recognition, signaling, adhesion, and fusion . 11 AFM is a tool that allows imaging and force probing biological samples with nanometer (nm) 3 topographical and piconewton (pN) force resolution .…”

“…16,17 This deflection is detected and processed as a function of the position on the (x, y) plane . 3,5,[17][18][19][20][21][22] The bending and torsion of the cantilever are measured based on the light beam reflection point of incidence on a four-quadrant photodetector . 16,[23][24][25][26][27] An optical lever is created by this light beam, from a laser or light-emitting diode, reflected by the cantilever onto the position-sensitive photodiode .…”