There could be new hope for people suffering from debilitating, slow-healing rotator cuff injuries. Chinese scientists have created a 3D printed implantable material that restores shoulder movement and stimulates the regrowth of torn tendons.
In a typical rotator cuff injury, one or more tendons that connect the shoulder muscles to the head of the humerus (upper arm bone) are partially or completely torn.
If the damage is relatively minor, the injury often heals on its own. However, more serious tears often require surgery to repair. Even then, the newly reintegrated tendons may not be able to withstand the loads placed on them by full use of the shoulder, ultimately leading to recurrence of the injury.
Looking for a more effective alternative to traditional surgical treatments, researchers from the Chinese University of Hong Kong have developed this new material.
It is a flexible, stretchable, biocompatible polythiourethane (PHT) elastomer that can be 3D printed to the exact size and shape required to cover each patient's wound. The printing process is easily carried out at room temperature, using visible light to convert gelatinous PHT resin into solid elastomer form.
After being sutured directly to the tear site of the injured tendon, the material mimics the mechanical properties of natural tendon tissue, immediately returning full range of motion to the affected shoulder. In laboratory experiments, it was able to be stretched at least 10,000 times without failing.
![This diagram shows how a cuff made of this material was used to close a 1cm gap on a rabbit's torn tendons.](https://assets.newatlas.com/dims4/default/50ffdee/2147483647/strip/true/crop/1120x568+0+0/resize/1120x568!/quality/90/?url=http%3A%2F%2Fnewatlas-brightspot.s3.amazonaws.com%2F02%2Fb9%2F08195045468d979da901eaf8ad7d%2F20240603-pic2.jpeg)
The Chinese University of Hong Kong
But what is important is the material Also contains two tendon-promoting growth factor proteins. These encourage cells from adjacent tendon tissue to grow into the material, which has a scaffold-like microstructure. Over time, as the elastomer gradually and harmlessly degrades, it is replaced by tendon tissue until nothing happens. but this tissue remains.
When tested on rabbits with rotator cuff injuries, the material was able to regrow tendons over a space of 1 cm (0.4 inch) over a period of eight weeks.
“Our work achieved the goal of developing a pro-regenerative, mechanically robust and easy-to-manufacture tendon biomaterial that corrects the mechanical and biological deficits of rotator cuff injuries while avoiding a complex and laborious production process,” says lead scientist Professor Elmer Ker. . “We will continue to demonstrate the significant potential of this newly developed material for the repair of large to massive rotator cuff injuries, as well as other soft tissue injuries, in the clinical setting.”
An article on the research was recently published in the journal Bioactive materials.
Scientists from the University of Connecticut have already Also successfully treated rotator cuff tears, using implantable mesh containing stem cells And graphene nanoplatelets.