The University of the Basque Country (Universidad del País Vasco) reports that one of its Ph.D. students has developed a new porous, biodegradable nanocompound support for the regeneration of bone tissue. According to UPV, Beatriz Olalde, in her doctoral thesis, reported on her approach that combines polylactic acid, hydroxyapatite and carbon nanotubes to form a material that could be used instead of bone grafts. Her material interacts chemically and electrically with bone cells and adjoining tissue to speed bone replacement and recovery.
Each of the components in Olalde’s foam-like material plays a specific role. The polylactic acid forms a basic biodegradable scaffold. Hydroxyapatite – a benign, bone-like bioceramic substance that is very compatible with tissues – is added attract cell growth and provide a source of calcium. The CNTs are added to provide strength. The CNTs also provide a material that reacts with an external electric field in a way that stimulates cell growth.
The desire for materials like Olalde’s (alloplastic grafts) stems from problems the medical profession faces when, due to events like large scale physical trauma or tumor removal, a patient loses a significant section of bone. Bone has the ability to regenerate itself to a large extent, but that requires time and support for the injured area.
Typically, bone grafts have been used either from the patient (an autograft), a living donor or a cadaver (allografts). But often a patient isn’t capable of providing the graft and donated bone raises complications due to tissue rejection issues, contamination, etc.
According to Olalde, trials involving both in vitro and in vivo experiments have shown satisfactory results. She says the foam displayed good mechanical properties and bone support. In in vivo trials, bone growth was observed after three weeks, and after 16 weeks this new bone showed mechanical, histomorphometric and densitometric properties similar to those of intact, healthy bone tissue.
Olalde has published before about polylactic acid and carbon nanotubes, and has collaborated with the University of Aberdeen, Scotland, and the Institute of Biomechanics of Valencia (IBV). She was awarded her Ph.D. and is currently working as a researcher in the Department of Biomaterials and Nanotechnologies Unit Tecnalia Health.