Atomic Force Microscopy (AFM) has several characteristics that make it useful for biomedical applications.

  • It can reveal smaller structures than are resolvable in optical microscopes.
  • It provides a true three dimensional map of surfaces
  • It can be done in air and in liquid (unlike electron microscopy)
  • Wide varieties of samples can be examined.

Bio-Molecules

One area of biomedical application is in the measurement and characterization of bio-polymers such as proteins and DNA.  Atomic force microscopy can be used to image such molecules as collagen:

Collagen

And individual monomers:

And DNA:

Once an image is captured, we can make measurements or perform other characterizations on the molecule.

Pharmaceutical powders

Another application of AFM is in measuring pharmaceutical powders such as those used to make pills.  The size and shape of powder particles affects how quickly they dissolve and can have other effects on their usefulness.  AFM is a valuable tool in measuring the size and shape of such particles.

Pharmaceutical compound in a polymer matrix. The pharmaceuticals form crystals while the polymer is amorphous The crystals can vary in size and shape, as can their distribution–sometimes dense, sometimes sparse. Production process variables can affect the size, shape, and distribution of the crystals which in turn can affect therapeutic effect. AFM provides a tool to understand what is happening and why some processes work better than others. This helps both researchers and manufacturers produce a better quality product more quickly at less cost.

Polymers for use in prosthetics and instruments.

Polymers for use in medical applications must meet extremely stringent standards.  The surface characteristics, and how those characteristics change over time, can be vital in how well those medical devices work.  The internal structure and composition of most polymers, including those used in the medical industry, is very complex.  Materials can “bloom” to the surface or can migrate across the surface, leading to unexpected changes in the function of medical devices.  Some of these changes can happen with a device simply sitting in storage.  With an atomic force microscope, one can test spots on the surface of a device and examine them again at the same spot from time to time to determine if changes are taking place.  This information can help determine the life expectancy of devices and components.

Example of dynamic effects, a surface changing over time. Lactose molecules in a thin film migrate, causing small surface structures to coalesce into fewer, larger structures.

Coatings and thin films

AFM Detects 1 Molecular Layer in Langmuir-Blodgett films of CH3-(CH2)14-COOH (C16) and the homologous C24 fatty acid

Coatings and films are vital to the proper function of many devices and components in the medical as in other fields. With AFM, one can examine coatings to detect material differences on the nanometer to micron scale and check whether the coating is continuous or perforated. This can be important in the proper function of medical devices and instruments. These are just a few of the ways in which AFM is used in the biomedical industry. For further information and to discuss your application, please contact us.