A scientific collaboration between the Sant’Anna School of Advanced Studies, the INAIL Prosthetic Center, the Rizzoli Orthopaedic Institute, and the Italian Institute of Technology (IIT) has led to the development of a new neural interface technology connecting the residual nervous system of a person with an amputation to an artificial prosthesis.
The research team, at the intersection of regenerative medicine and prosthetics, developed a regenerative peripheral nerve interface (RPNI) to offer new possibilities for prosthetic control.
They developed an engineered muscle construct by combining myoblasts, stem cell precursors of muscle tissue, with innovative biomaterials. This neomuscle was subsequently surgically connected to a peripheral nerve in a preclinical model of nerve injury, creating a functional connection between nerve and muscle tissue.
“Our approach integrates advanced tissue engineering strategies with the field of prosthetics,” said Leonardo Ricotti, PhD, professor at the Sant’Anna School of Advanced Studies and head of the Regenerative Technologies Lab. “To promote the maturation of muscle tissue and its integration with nerve tissue, we used piezoelectric particles, materials capable of generating electrical signals when subjected to mechanical stimuli. External stimulation was provided through pulsed ultrasound, a noninvasive technology already used in several biomedical fields, but which we have applied in an innovative way in this study.”
The research introduces two major scientific innovations, the researchers said. First, it represents the first documented case of an RPNI created using tissue engineering techniques and subsequently implanted and connected to a peripheral nerve. Second, it demonstrates how the combination of piezoelectric particles incorporated into the muscle construct and ultrasound stimulation can promote both muscle tissue maturation and nerve tissue regeneration.
“This result represents a key step towards the future control of advanced prostheses, as it makes it possible to acquire and amplify signals from the residual nervous system of a person with an amputation and use them to achieve natural and intuitive control,” said Christian Cipriani, PhD, professor, Sant’Anna School of Advanced Studies and head of the Artificial Hands Area.
“The researchers’ long-term goal is to develop a new generation of bionic prostheses with multiple degrees of freedom that patients can control naturally. In this scenario, a network of regenerative neural interfaces could provide a stable connection between the nervous system and the prosthetic device,” said Emanuele Gruppioni, PhD, technical director, Research and Training Area, INAIL Prosthetic Center. “The muscle constructs developed as part of the study could also act as genuine biological amplifiers of nerve signals, enable increasingly complex movements and significantly improve the quality of life of people with amputations.”
“The next challenge is to translate these technologies from research into clinical practice,” said Paolo Sassu, MD, orthopedic surgeon, Rizzoli Orthopaedic Institute. “Modern bionic limb reconstruction stems precisely from the integration of surgery, neuroengineering, and advanced prosthetics: Through dedicated surgical procedures, we can create new biological interfaces with the nervous system and make them available for prosthetic control. We are working on this multidisciplinary integration to develop a dedicated program for bionics and advanced limb reconstruction.”
Editor’s note: This story was adapted from materials provided by Sant’Anna School of Advanced Studies.
The open-access study, “Ultrasound-activated piezoelectric muscle constructs for tissue-engineered regenerative peripheral nerve interfaces,” was published in Bioactive Materials.
