Engineered bone (NMW.4457)

Present state-of-the-art in reconstructive head and neck surgery, is microsurgical transfer of autogenous tissue. Complex reconstructions demand the use of composite flaps which coincide with significant donor site morbidity. A recent development within plastic and reconstructive surgery is the prefabrication of flaps. This technique delivers a functional anatomical vascular unit to tissue otherwise unfit for microsurgical transfer. This technique can be used to transfer pre-shaped tissue engineered bone grafts, with little donor site morbidity. A substance of which is proven that it can induce bone formation is Bone Morphogenetic Protein (BMP). BMP's comprise a growing family of more than 12 proteins. Nine of them have shown to encourage bone formation. BMP2, that shows a high osteoinductive potential can be synthesized using recombinant DNA technology. The application of these BMPs in bone regeneration requires use of a suitable carrier material. The scaffold has to allow cell adhesion and must have adequate mechanical properties to withstand and transport loads known to be present in bone. Besides mechanical properties the scaffold should allow controlled delivery of BMPS. Until now, mostly biodegradable polymeric materials (polylactic acid, polyglycolic acid (Vicryl) are used. The disadvantage of these materials is that they are not very strong and can easily transform. A solution for this problem can be found by using a metallic fiber product, like porous titanium mesh, as scaffold material. A pilot study with rats, did already prove the BMP-Ioaded titanium mesh indeed can induce bone formation. Further, this bone formation did again increase when the mesh material was provided with an additional thin calciumphosphate (Ca-P) coating. In view of the above mentioned, the current grant proposal deals with four questions.

1. are the above mentioned results consistent in large animals, other locations, and after longer implantation periods?
2. can scaffold surface treatments further increase the loading efficacy and bone inducing effect of BMP?
3. can the titanium mesh principle be used to create vascularized bone grafts?
4. can bone defects be reconstructed with functional preshaped engineered bone grafts?

The final goal of this project is to deliver a technique that can be used to design and grow preshaped bone graft substitutes into the human body, which can be used for reconstructive purposes.

Gebruikers

Er zijn één bedrijf, twee anderee universiteiten en drie instellingen bij dit project betrokken.

Projectleider

Prof.dr. J.A. Jansen
Katholieke Universiteit Nijmegen
Medische wetenschappen
Vakgroep Orale Functieleer
Afd. Biomaterialen
Postbus 9101
6500 HB Nijmegen

Status van het project

Gestart	: 01-07-1998
Einddatum	: 01-09-2002

Trefwoorden

Biomaterialen; Bottransplantaat; Implantaten; Plastische chirurgie. .