UH researchers capture real-time growth images of cholesterol crystals

University of Houston researchers have made a breakthrough in understanding how cholesterol crystals form, using innovative imaging techniques. Professors Jeffrey Rimer and Peter Vekilov, both from the University of Houston's Chemical Engineering department, have successfully captured real-time images showing the growth of cholesterol crystals at near molecular resolution.

The study reveals how these crystals develop in environments that mimic the human body. This research is significant because cholesterol crystals are linked to diseases such as heart disease and gallstones. Despite their importance, there has been limited research into the specific processes by which cholesterol forms crystals.

Rimer and Vekilov's findings have been published in the Proceedings of the National Academies of Science. The professors are known for their contributions to crystal engineering and therapeutics design aimed at preventing crystallization in human diseases.

According to Rimer, "These insights provide a foundation for future design of modifiers that selectively interact with crystal surfaces to cooperatively enhance growth inhibition, thus generating new opportunities to discover therapeutics that improve human health by counteracting the deleterious effects associated with cholesterol precipitation."

The team discovered that cholesterol crystals grow in layers within a special solvent designed to replicate physiological conditions. This solvent allows scientists to observe crystal growth as it happens. Vekilov explained, “Using a binary mixture of water and isopropanol, with the latter serving as a surrogate for lipids in physiological environments, we show that cholesterol monohydrate crystals grow classically by the nucleation and spreading of new crystal layers.”

Time-lapse images documented by the researchers illustrate how thin and thick cholesterol crystals evolve over time inside a small fluid device. Rimer noted, “Time-resolved imaging confirms that layers are generated by dislocations and monomers incorporate into advancing steps after diffusion along the crystal surface and not directly from the solution.”

The findings challenge previous assumptions about classical mechanisms leading to unhindered growth through single layer spreading.