Microspheres filled with cells will help to heal wounds

Nanofiber microspheres give hope to patients with complex cartilage injuries
NanoNewsNet based on materials from the University of Michigan:
Researchers inject nanofiber spheres carrying cells into wounds to grow tissue

Scientists from the University of Michigan School of Dentistry have created a biodegradable polymer capable of self-assembling into hollow microspheres. When injected into a wound, such microspheres with the cells in them gradually degrade, and the cells continue to live, forming a new tissue.

The development of such a sphere as a carrier of cells that mimics the natural environment for their growth – the intercellular matrix, represents a significant achievement in the field of tissue repair, says Professor Peter Ma, lead author of an article on a new strategy published online in the journal Nature Materials (Nanofibrous hollow microspheres self-assembled from star-shaped polymers as injectable cell carriers for knee repair).

Tissue repair is a very difficult task, and the possibilities of its successful solution are extremely limited by the shortage of donor tissue. The process developed by American scientists gives hope to patients with certain types of cartilage injuries, for which there are currently no good treatment methods. It represents the best alternative to autologous chondrocyte implantation (ACI), a clinical method of treating cartilage injuries by directly injecting the patient's own cells. The quality of tissue repair by the ACI method cannot be called good, since it does not allow achieving the necessary accuracy of cell insertion, and cell growth is not supported by any carrier simulating the natural environment.

For the treatment of complex and unusual forms of tissue defects, an injectable cell carrier is desirable. Using biodegradable nanofibers, Professor Ma's laboratory is developing a strategy for creating a biomimetic cell matrix that copies living systems and supports cells during their growth and tissue formation.

Hollow microspheres made of nanofibers are extremely porous, which is very important, since they must be penetrated by substances that feed cells, and mimic the functions of the cell matrix of a living organism. In addition, when degraded, they do not form a large number of decay byproducts that can disrupt cell growth.

For the first time, scientists have developed a star-shaped biodegradable polymer,
forming hollow porous microspheres by self-assembly,
which perform the function of a cell carrier,
simulating the natural environment,
favorable for their growth
and tissue regeneration.
(Photo: University of Michigan)

Nanofiber spheres are filled with cells and injected into the wound. By the time the spheres degrade, cell growth has already been given a good start, since the biomimetic matrix has provided them with the environment in which they feel great in natural conditions.

This approach has proved to be more successful than using a traditional gel matrix used for tissue regeneration at the present time. There is still no way to make such a matrix injectable, and it is not applicable for delivering cells to wounds of complex configuration.

So far, nanofiber microspheres have been tested only on rabbits. In the group with the injected new carrier, the observed tissue growth was three to four times greater compared to the control. The next step is to find out how microspheres with cells will behave in the body of large animals and, ultimately, humans.

Portal "Eternal youth" http://vechnayamolodost.ru01.06.2011