A team at Northwestern University have developed a new organic printing material that could revolutionise regenerative medicine. The key to this remarkable discovery lies in the ability to control the way in which molecules combine to form tissues and cells. The printing process involves taking sample cells from a patient, and then creating living, functional tissues in the lab for research or reinsertion back into the patient.
The idea came from a study conducted in 2018 by lead scientist and pioneer in supramolecular self-assembly, Samuel I Stupp. He showed that biomaterials could be programmed to travel to a specific site in the body and then reassemble to form super-structured bundles of nanofibres.
From this initial result, his team have extended their studies to investigate how these super-structures can be used to target neuron growth, with a view to finding methods of reversing neurodegenerative diseases via cell transplantation.
The biomaterial involves mixing two reactive liquids that can lock and unlock from each other at the molecular level. This enables the key components to effectively move over one another like a tank track until they reach the desired destination. At this point, the molecules reorganise into useful protein bundles.
Unlike other biomaterials, such as polymer hydrogels, these active bundles and super-structures create pores large enough for other cells to move through or even combine with the chemical signatures deliberately embedded within the biomaterial. The result is a compound which can migrate to damaged regions of the body and assemble into new tissue such as healthy brain cells.
It also enables different types of lab-built cells to aggregate and connect purely for research purposes. Understanding critical interactions between the neural cells could further neurology and regenerative medicine without the need to use human guinea pigs.
At present, the team are using the biomaterial as a scaffold to deliver a chemical that stimulates the natural growth of brain cells in and around the nano structure, thus encouraging brain tissue to reseed itself like an artificial coral reef, but there are plans to apply this technique elsewhere in the body. Using different chemical signalling, Stupp believes that other tissues that are typically tricky to treat can be stimulated to self-heal.
Stupp states, “Cartilage and heart tissue are very difficult to regenerate after injury or heart attacks, and the platform could be used to prepare these tissues in vitro from patient-derived cells. These tissues could then be transplanted to help restore lost functions. Beyond these interventions, the materials could be used to build organoids to discover therapies or even directly implanted into tissues for regeneration since they are biodegradable.”
Despite the fact that jet injection devices have fallen from favour in recent years, I envision a future of spray-on bio targeted solutions replacing the need for minor injuries clinics and surgeries. Imagine, if you will, an accident in the garden leaving you with a painful ligament or tendon. The treatment offered today would involve strapping to keep the joint immobile and perhaps surgery, before many weeks of discomfort, physiotherapy and stress while it slowly heals.
With a biomaterials system, a quick visit to a local medical centre would allow for a small sample of the patient’s cells to be taken using a biopsy needle so that a machine could then mix it with all the necessary chemical tracking markers and reagents needed to stimulate expedited growth. The same practitioner could then spray or inject the tailored healing solution back into the injury site. Within a short period of time, the ligament would heal or reattach with no repeated injury risk. In effect, it would be as good as new – no scar tissue or weakened function.
Similarly, new blood vessels could be grown around damaged heart tissue instead of open-heart surgery and grafts, or Alzheimer’s Disease could be reversed with neuro regeneration. The potential for triggering rapid repair in the body is limitless, perhaps even growing whole new organs from your own stem cells.
This study is an extraordinary stepping stone into a new era of medicine, one that works in harmony with the existing structures and chemicals already found in our bodies, instead of administering potentially toxic ones or splicing parts from another person in place of damaged ones.
Science Fiction films and TV series are not that far ahead of science reality anymore, and that is surely a cause for hope and celebration.
Source – Alexandra N Edelbrock, Samuel I Stupp et al, Superstructured Biomaterials Formed by Exchange Dynamics and Host-Guest Interactions in Supramolecular Polymers – Advanced Science, 2021.