Cell-to-Cell Communication Prompted by Calcium Signals Using Light-Activated Molecular Machines Provides a New Strategy in Drug Design

The human body is made up of trillions of cells, each doing their own specific function. However, they are also able to work as a group through complex system of networks. Intercellular communication is a very crucial element in coordinating important biological activities such as hormone release, digestion, muscle contraction, neuron firing, and immune activation.

Triggering Intercellular Coordination

In Rice University, a group of scientists attempted to prompt intercellular calcium wave signals by using light-activated molecular machines. Conventional drugs use chemical binding forces in driving streams of specific signals in the body. The research team believes that a mechanical force can be used as a substitute to chemical force in binding such signals.

Headed by chemistry graduate student Jacob Beckham, the experts use single molecule nanomachines in inducing the mechanical force. To make this possible, they relied on an actuator which rotate upon stimulation of visible light. As a result, a calcium-signaling response is induced in smooth muscle cells.

The molecular machines are activated by light pulses generated at a quarter second, enabling scientists to manipulate calcium signaling in a cell culture of cardiac myocyte. According to Beckham, the molecules function as nano-defibrillators which target the inactive heart muscle cells.

Stimulating just one heart cell can lead to the propagation of signals to the neighboring cells as confirmed by materials science and nanoengineering professor James Tour. In his laboratory, Tour has previously shown that it is possible to deploy light-activated molecular machines to fight against antibiotic-resistant infectious bacteria, cancer cell, and fungi.

When they tried to apply this calcium-based cellular signaling mechanism in a living organism, the experts discovered that it could trigger a whole-body contraction in a fresh-water polyp. This is the first instance of successfully using a molecular machine in controlling an entire functioning organism.

The result of this study provides new insight in controlling cellular activity, leading to enhanced treatment for patients who suffer from heart problems, digestive health issues, and more. Beckham and his colleagues are looking forward to the creation of light-activated machines which can offer deeper penetration. In addition, they also plan to better understand the actual biological processes at a molecular level.

Importance of Controlling Cellular Activity

Humans are not endowed with the ability to consciously control most of the critical muscles in our own body. For instance, we cannot control our blood pressure and circulation because the heart works as an involuntary muscle while our veins and arteries are lined with smooth muscle tissue. Digestion and breathing are also beyond our control due to the presence of smooth muscles that cover our lungs and intestines.

It will be a game-changing feat in science if these processes can be manipulated with a molecular-level mechanical stimulus. Having the ability to control intercellular communication in muscle tissue can be very useful in treating a wide range of diseases brought by dysfunctional calcium signaling.

In the case of paralyzed patients, they can suffer from digestive problems due to inactive cells. It will be a breakthrough in medicine if such issues can be solved without the need to use chemical intervention.