Microscopy has long been an essential tool in the field of scientific research, enabling scientists to observe and study various biological samples with precision and detail. In recent years, there have been significant advancements in the field of microscopy, particularly in the area of super-resolution imaging. Researchers at Bielefeld University in Germany have developed a fluorescence microscope that utilizes structured illumination for fast super-resolution imaging over a wide field of view. This breakthrough brings with it the potential to revolutionize the study of drug effects on the body and improve personalized healthcare.
Polypharmacy, the practice of prescribing multiple drugs to chronically ill or elderly patients, has become a growing concern due to the potential for dangerous interactions. The new microscope developed by the researchers at Bielefeld University is part of the EIC Pathfinder OpenProject DeLIVERy, which aims to develop a platform for investigating polypharmacy in individual patients. By imaging multiple living cells simultaneously with high resolution, the microscope allows for the study of the effects of various drug combinations on the body.
The novel microscope described in the study utilizes optical fiber delivery of excitation light to achieve high image quality over a wide field of view. This enables the imaging of liver cells with a field of view up to 150 x 150 μm2 at imaging rates up to 44 Hz. The microscope maintains a spatiotemporal resolution of less than 100 nm, allowing for precise observation of cell membrane features and organelles.
One of the key advantages of this new microscope is its ability to test individual drug combinations on isolated cells and then image them with super-resolution. This capability provides valuable insights into the dynamics of cell membrane features and organelles. Additionally, the large field of view allows for statistical information about cell response, which could be utilized to enhance personalized healthcare. Another noteworthy advantage is the potential for the microscope’s compact size to be useful in clinical applications where high resolution is critical.
The new microscope is based on the concept of SR-SIM, which uses a structured pattern of light to excite fluorescence and achieve a spatial resolution beyond the diffraction limit of light. SR-SIM is particularly well-suited for live cell imaging as it utilizes low-power excitation that does not harm the sample while still producing highly detailed images. In order to achieve high resolution across a wide field of view, the microscope reconstructs super-resolved images from a set of raw images.
To acquire the necessary raw images, the researchers employed a set of six optical fibers that illuminate the sample with a sinusoidal striped pattern. This pattern is shifted and rotated to gather additional information, resulting in a two-fold resolution improvement. The selection of fibers and phase shift is facilitated by a newly designed fiber switch based on galvanometric mirrors and MEMS-mirrors. In addition, a hexagonal holder was custom-designed to collimate and refocus the beams of the six fibers into the microscope, allowing for precise adjustment and illumination of a large field of view. This setup is also compatible with total internal reflection fluorescence excitation (TIRF)-SIM, which restricts fluorescence excitation and detection to a thin region of the sample.
As the liver is the primary organ involved in drug metabolism, the researchers conducted tests using samples of fixed multicolor-stained rat liver cells. The reconstructed images obtained with the new microscope provided visualization of minute membrane structures that are smaller than the diffraction limit of light. This breakthrough demonstrates the capability of the microscope to capture and analyze cellular structures with unprecedented detail.
The Road Ahead
Moving forward, the researchers plan to apply this microscopy setup to live cell studies of liver cells. By observing the dynamics of cells treated with multiple drugs, they hope to gain valuable insights into the effects of these drugs on cellular behavior. Additionally, efforts will be made to enhance the image reconstruction process, enabling live reconstruction of acquired raw data. These advancements in super-resolution imaging hold the potential to revolutionize the field of healthcare and contribute to the development of personalized medicine.
The development of a fluorescence microscope that utilizes structured illumination for fast super-resolution imaging marks a significant milestone in the field of microscopy. This groundbreaking technology has the potential to revolutionize the study of drug effects on the body, particularly in polypharmacy cases, and improve personalized healthcare. With its ability to provide high resolution over a wide field of view, this microscope holds promise for future applications in clinical settings. As advancements continue to be made in super-resolution imaging, the future of microscopy looks increasingly bright.