Revolutionary 'Dancing Molecules' Repair Tissues and Regenerate Cartilage in Just Hours

The field of regenerative medicine has just taken a significant leap forward with the development of injectable “dancing molecules” that can repair tissues and regenerate cartilage in a matter of hours. Researchers at Northwestern University, who first introduced this innovative therapy in November 2021 for treating spinal cord injuries, have now successfully applied it to damaged human cartilage cells.

The Breakthrough Study

In the new study, published in the Journal of the American Chemical Society, the treatment activated the gene expression necessary to regenerate cartilage within just four hours. Moreover, the researchers found that the treatment’s effectiveness increased as the molecular motion increased. The molecules’ “dancing” motions were crucial for triggering the cartilage growth process.

“When we first observed therapeutic effects of dancing molecules, we did not see any reason why it should only apply to the spinal cord,” said Samuel I. Stupp, the lead researcher. “Now, we observe the effects in two cell types that are completely disconnected from one another — cartilage cells in our joints and neurons in our brain and spinal cord. This makes me more confident that we might have discovered a universal phenomenon. It could apply to many other tissues.”

The Problem of Osteoarthritis

Osteoarthritis is a degenerative disease that affects nearly 530 million people worldwide, according to the World Health Organization. It is a common health problem and leading cause of disability. In severe cases, cartilage can wear so thin that joints essentially transform into bone on bone, leading to immense pain and loss of joint function. The only effective treatment currently is joint replacement surgery, which is expensive and invasive.

“Current treatments aim to slow disease progression or postpone inevitable joint replacement,” said Stupp. “There are no regenerative options because humans do not have an inherent capacity to regenerate cartilage in adulthood.”

What Are 'Dancing Molecules'?

“Dancing molecules” are assemblies that form synthetic nanofibers comprising tens to hundreds of thousands of molecules with potent signals for cells. By tuning their collective motions through their chemical structure, Stupp discovered that the moving molecules could rapidly find and properly engage with cellular receptors, which are also in constant motion and extremely crowded on cell membranes.

“Cellular receptors constantly move around,” said Stupp. “By making our molecules move, 'dance' or even leap temporarily out of these structures, known as supramolecular polymers, they are able to connect more effectively with receptors.”

Motivating Motion

In the new study, the researchers targeted the receptors for a specific protein critical for cartilage formation and maintenance. To do this, they developed a new circular peptide that mimics the bioactive signal of the protein, called transforming growth factor beta-1 (TGFb-1).

The researchers incorporated this peptide into two different molecules that interact to form supramolecular polymers in water, each with the same ability to mimic TGFb-1. However, they designed one supramolecular polymer with a special structure that enabled its molecules to move more freely within the large assemblies, while the other supramolecular polymer restricted molecular movement.

“We wanted to modify the structure in order to compare two systems that differ in the extent of their motion,” said Stupp. “The intensity of supramolecular motion in one is much greater than the motion in the other one.”

What’s Next?

Stupp’s team is currently testing these systems in animal studies and adding additional signals to create highly bioactive therapies. “With the success of the study in human cartilage cells, we predict that cartilage regeneration will be greatly enhanced when used in highly translational pre-clinical models,” said Stupp.

The researchers are also testing the ability of dancing molecules to regenerate bone, with promising early results. Additionally, they are testing the molecules in human organoids to accelerate the process of discovering and optimizing therapeutic materials.

FAQs

• What are “dancing molecules”? Dancing molecules are assemblies that form synthetic nanofibers comprising tens to hundreds of thousands of molecules with potent signals for cells. They are designed to mimic the extracellular matrix of the surrounding tissue.
• How do dancing molecules work? Dancing molecules work by rapidly finding and properly engaging with cellular receptors, which are also in constant motion and extremely crowded on cell membranes.
• What is osteoarthritis? Osteoarthritis is a degenerative disease that affects nearly 530 million people worldwide, characterized by the breakdown of tissues in joints over time.
• What is the current treatment for osteoarthritis? The current treatment for osteoarthritis aims to slow disease progression or postpone inevitable joint replacement, with no regenerative options available.

Conclusion

The development of injectable “dancing molecules” is a revolutionary breakthrough in regenerative medicine. With its potential to repair tissues and regenerate cartilage in a matter of hours, this innovative therapy holds promise for treating a range of debilitating conditions, including osteoarthritis. As researchers continue to test and refine this therapy, we can expect to see significant advancements in the treatment of various diseases and injuries.