Advancements in Drug Discovery through Chemistry, Robotics, and AI

Valuable insights into the integration of digital chemistry, robotics, and AI in the drug discovery process

Researchers in the UK have successfully addressed optimization problems that are typically handled by quantum computers using the pulsating Belousov-Zhabotinsky (BZ) reaction. Lee Cronin's research team at the University of Glasgow utilizes a system of interconnected wells that employ color oscillations to store and transmit information. According to Cronin, it would be quite amusing if a chemical computer could outperform a quantum computer in message decryption, as he mentioned to Chemistry World. However, there are still doubts among experts regarding the feasibility of such an accomplishment.

Many unconventional computers utilize BZ color changes. The Glasgow team has developed two sets of 3D-printed arrays with interconnected wells. There is a row with seven wells, while the other is a complete grid with a size of 7x7. Every well in the array has a small space between its walls, and the wells on the outer edge of the array partially touch the walls. Within these walls, pipes deliver the necessary chemicals for BZ reactions. Wells exhibit a fascinating interplay of red and blue hues when sulfuric and malonic acid interact with ferroin indicator and potassium bromate.

The magnetic stirrer bars were placed in the center of each well and gap by the researchers. Each stirrer can be controlled individually by using magnets attached to separate motors. In order for a BZ oscillation to occur, it is necessary for the central stirrer to be turned on.

The gaps have been enhanced in the group's latest design, allowing for improved control of reagent flow between wells. Activating stirrers in the gaps creates a synchronized flow that brings harmony to the color changes of the BZ reaction, preventing them from drifting out of time. Unlike the familiar digital computers, the BZ computers utilize finite state logic, as the wells only exist in a limited number of states.

The Glasgow team demonstrates an introductory stage in the array by using BZ pulses that transition between different shades of blue and red. They utilize a form of artificial intelligence (AI) to categorize the state. The AI takes charge of manipulating the digital inputs for the stirrers, determining the appropriate pulse state and adding reagents accordingly. However, the researchers argue that the AI does not solely determine the pulse state. Instead, chemical interactions can play a role in the formation of the new state.

Cronin's team utilizes their BZ computers to showcase cellular automata, which are widely recognized as examples of state machines. Cellular automata undergo changes over time based on specific rules, as exemplified by the well-known Game of Life.

In the BZ computer cellular automata, patterns of pulses evolve in a specific order. By disabling stirrers in the gaps between cells when they're not synchronizing pulses, the computer can precisely adhere to this sequence. Leaving the stirrers in the gaps on, however, creates fascinating 'emergent' patterns as chemical information flows between and is stored within cells. The Glasgow chemists aimed to utilize emergent behavior to tackle mathematical problems through quadratic unconstrained binary optimization, a field currently being explored by quantum computers.

Theodore Gray, a renowned chemistry author and co-founder of Wolfram Research, shares his thoughts on the potential of a certain approach in an interview with Chemistry World. He questions whether there is a way for this technique to be more efficient or cost-effective than silicon chips, despite its claimed effectiveness. He also questions its ability to solve optimization problems more efficiently than quantum computers.

According to Ben de Lacy Costello from the University of West of England, there are numerous approaches to utilizing BZ computers. 'This could be just another one of those,' de Lacy Costello remarks. However, he finds the engineering involved quite impressive.

Cronin's team is currently working on developing a compiler that utilizes the BZ reaction for versatile computing purposes. He acknowledges that there may be instances where the computer's performance is slower compared to others. However, it could be more energy-efficient and potentially faster for optimization problems. 'Encoding the optimization is a straightforward task,' he says.

Source: A Sharma et al, Nat. Commun., 2024, 15, 2421 (DOI: 10.1038/s41467-024-46859-8); Bio International Convention