Super-resolution label-free volumetric vibrational imaging.

Area of Science:

• Biomedical Imaging
• Optical Microscopy
• Biophysics

Background:

• High-resolution optical imaging advances visualization of nanoscale biological structures.
• Super-resolution fluorescence techniques face limitations in quantification and throughput due to photobleaching, quenching, and inefficient probe delivery in tissues.

Purpose of the Study:

• To introduce a novel sample-expansion vibrational imaging strategy, VISTA, for scalable, label-free, high-resolution imaging.
• To overcome limitations of current super-resolution fluorescence techniques in tissue imaging.

Main Methods:

• Developed VISTA, a general sample-expansion vibrational imaging strategy.
• Achieved high-resolution imaging (down to 78 nm) through optimal endogenous protein retention, isotropic sample expansion, and lipid deprivation.
• Correlated VISTA with immunofluorescence and trained an image-segmentation model for label-free component prediction.

Main Results:

• VISTA provides label-free, high-resolution (78 nm) imaging of protein-rich biological structures.
• The method demonstrates unbiased and high-throughput tissue investigation capabilities, free from probe-labeling issues.
• Successful label-free prediction of nucleus, blood vessels, neuronal cells, and dendrites in mouse brain tissues was achieved using a trained segmentation model.

Conclusions:

• VISTA offers a versatile platform for scalable, label-free, high-resolution imaging of biological tissues.
• This technique overcomes key limitations of fluorescence-based super-resolution microscopy.
• VISTA opens new avenues for diverse biomedical studies requiring detailed tissue interrogation.