It is a new neural interface technology to improve the connection between the residual nervous system of the patient with an amputation and the artificial prosthesis.
The latest frontier of innovation in the field of regenerative medicine and prosthetics has led to the development of a regenerative peripheral nerve interface (RPNI) which opens new perspectives in prosthesis control. The study, published in the international journal Bioactive Materials, is the result of a scientific collaboration between the Scuola Superiore Sant’Anna in Pisa, the INAIL Prosthetic Center, the Rizzoli Orthopedic Institute, and the Italian Institute of Technology – IIT.
The research team developed an engineered muscle construct obtained by combining myoblasts, i.e., stem cell precursors of muscle tissue, and innovative biomaterials. This neo-muscle was subsequently surgically connected to a peripheral nerve in a preclinical model of neural damage, giving rise to a functional connection between nervous tissue and muscle tissue.
“Our approach integrates advanced tissue engineering strategies with the world of prosthetics. To promote the maturation of the muscle tissue and its integration with the nervous tissue, we used piezoelectric particles, materials capable of generating electrical signals when subjected to mechanical stimuli. External stimulation was achieved through pulsed ultrasound, a non-invasive technology already used in several biomedical fields, but which in this study we exploited in an innovative way,” declares Leonardo Ricotti, professor at the Scuola Sant’Anna and head of the Regenerative Technologies Lab.
The research introduces two important scientific novelties. On one hand, it represents the first documented case of a regenerative peripheral nerve interface created through tissue engineering techniques and subsequently implanted and connected to a peripheral nerve. On the other hand, it highlights how the combination of piezoelectric particles integrated into the muscle construct and ultrasound stimulation can promote both the maturation of muscle tissue and the regeneration of nervous tissue.
“This result represents a fundamental element for the future control of advanced prostheses, as it allows for the acquisition and amplification of signals coming from the residual nervous system of the amputee, leveraging them for natural and intuitive control,” declares Christian Cipriani, professor at the Scuola Sant’Anna and head of the Artificial Hands Area.
“The long-term goal of the researchers is the creation of a new generation of bionic prostheses equipped with numerous degrees of freedom and naturally controllable by patients. In this scenario, a network of regenerative neural interfaces could serve as a stable link between the nervous system and the prosthetic device,” declares Emanuele Gruppioni, Technical Director of the Research and Training Area of the INAIL Prosthetic Center. “The muscle constructs developed within the scope of the study could also act as genuine biological amplifiers of nerve signals, enabling the execution of increasingly complex movements and significantly improving the quality of life for people with amputations.”
“The next challenge is to transfer these technologies from research to clinical practice,” emphasizes Paolo Sassu, orthopedic surgeon at the Rizzoli Orthopedic Institute. “Modern bionic limb reconstruction is born 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 usable for prosthesis control. It is on this multidisciplinary integration that we are working to develop a program dedicated to bionics and advanced limb reconstruction.“
“Bringing advanced characterization techniques, such as transmission electron microscopy, into an interdisciplinary study of this caliber that combines regenerative medicine and prosthetics, was our way of contributing to a complex challenge that opens new perspectives in the development of prostheses,” adds Mauro Gemmi, lead researcher of the Electron Crystallography unit of the Italian Institute of Technology – IIT.
