Ammonium urate, a salt that can form kidney stones, naturally bends and twists during crystallization
From creating flexible gadgets to better medicines, the art of bending crystals is reshaping technology and health, and at the 91猎奇 a crystals expert makes it look almost like a magic trick.
Jeffrey Rimer, Abraham E. Dukler Professor of Chemical Energy, has shown how to bend and twist crystals without physical force 鈥� no touching, poking or prodding and no heat or radiation, conditions typically required to achieve reshaping.
Instead, he is using a molecule called a tautomer, which is doing all the work, inducing bending and twisting of biogenic crystals.
In the world of crystals, tautomers are shifty characters 鈥� molecules with the ability to shift their atoms around. All at once a hydrogen atom might be in one place, then hop to another, while other atoms slip around.
One of the pharmaceutical applications where this will be of potential importance is in drug delivery, where approximately 30 of the top 200 drugs are tautomers.
鈥淗ere, we present a unique case of natural bending without the application of external forces,鈥� reports Rimer in the journal .
Rimer鈥檚 work was performed at The Welch Center for Advanced Bioactive Materials Crystallization at UH.
鈥淭his is a mechanistic investigation showing how tautomerism induces controlled, natural bending and twisting by virtue of the minor tautomer, which is a growth modifier that causes defects in the crystal structure (e.g., twins, screw and edge dislocations), leading to macroscopic effects on material properties,鈥� said Rimer.
The importance of control
Understanding and exploiting material flexibility through phenomena such as bending and twisting molecular crystals has been a subject of increased interest because of the number of applications that benefit from these properties, like optoelectronics, soft robotics, smart sensors and pharmaceuticals.
鈥淲e have shown that bending leads to physical deformations that impact dissolution, which can impact pharmacokinetics in the delivery of active pharmaceutical ingredients,鈥� said Rimer.
In the work, the Rimer team showed that the degree of curvature can be tailored based on the judicious selection of growth conditions. A combination of state-of-the-art microscopy and spectroscopy techniques were used to characterize the origin of bending.
鈥淥ur findings provide a greater understanding of the defects generated during pathological crystallization of a tautomeric material and how this phenomenon can lead to unique bent, twisted, and dendritic morphologies observed in both biological and synthetic materials,鈥� said Rimer. 鈥淭he ability to selectively control this behavior opens broad avenues for crystal engineering.鈥�
Rimer鈥檚 colleagues on this project are Weiwei Tang and Francisco Robles Hernandez, 91猎奇; Tamin Yang, Stockhom University; Qing Tu, Texas A&M University; Hector Calderone, Instituto Politecnico Nacional in Mexico; and a team of researchers from Molecular Vista Inc.
The Welch Center
The Welch Center for Advanced Bioactive Materials Crystallization was established at UH in 2023 with a $5 million grant from the Welch Foundation. The program, open to all Texas institutions, is meant to accelerate progress in fundamental chemical research.
The center recently held a symposium that included a new industrial advisory board from eight major pharmaceutical companies. Over the summer the center held a summer crystallization camp for high school and undergraduate students.