Duration: 2005 – 2008
There are roughly 1 million cases in the USA and ½ million in EU of high skeletal defects a year. All of these cases require bone-graft procedures to achieve union, each of which requires the surgeon to determine the type of graft material to be use. The toughest challenge appears when the size of the defect is too big and the reconstruction of this defect requires a bone graft capable of supplying similar physical properties and behavior to the bone being substituted. Unfortunately at this moment commercial scaffolds can not satisfy the following issues:
- To promote new bone formation in order to reduce the time of bone healing and decrease the vascular insult of the implant to the bone and cause less-stress shielding.
- Mechanical properties that match those of human tissue to be regenerated during its new formation.
- Large segment of implants. For patients who have lost large segments of bone due to a congenital defect, degenerative diseases, cancer or accident.
Based on these basic needs to provide an ideal scaffold, the NANOBIOCOM project aims at establishing the scientific and technological basis for the development new ‘intelligent’ composite scaffold for bone tissue repair and regeneration with the following issues:
- Bioactive behavior capable of activating osteoprogenitor cells and genes and within an in vivo environment provide the interface to respond to physiological and biological changes.
- Mechanical and structural properties similar to a healthy bone.
- Size and shape required for reconstructing big skeletal defects.
NANOBIOCOM focuses on the development of an intelligent material with the following challenges:
- The bioactivity of the composite, which is rendered by the bioactive components (nanoparticles, carbon nanotubes, polymers) in the composite and/or by external stimulation (BMP’s, Electrical Fields, biofunctionalitation) will active osteoprogenitor cells and gens, and consequently promote the tissue growth adjacent to the implant.
- Mechanical and structural properties of the scaffold equal to a healthy bone synchronous with new bone formation. By the incorporation of nanoparticles as carbon nanotubes and nanohidroxiapatite into the composite are expected to be highly suitable reinforcement for the implants of the load bearing structures of our body such as bone and cartilage.
- The size and shape of biodegradable implants. We are going made large segments of implants required for reconstructing big defects capable of supplying similar physical properties and behavior of healthy bone to be replaced, in contrast with the small implants that are made at present.
- Understanding the genetic programming of bone regeneration. To realize the potential for novel ‘intelligent’ composite materials to serve as scaffolds for bone regeneration requires that the innate programming mechanisms involved in bone development and repair are effectively harnessed.
The main output of NANOBIOCOM project will be:
- An appropriate cell bioactive system to initiate repair and regeneration of bone.
- Intelligent composite for 3D scaffold, which will be able to support physiological loading until sufficient tissue regeneration occurs and will be possible manufacture large segments.
- A comprehensive gene expression profiles of the temporal regulation of gene expression during bone development.
The main objectives proposed are:
- To optimize osteoblast activation (such as cell proliferation, collagen type I formation, and > 50% accumulation of calcium-containing mineral in the extracellular matrix) pertinent to new bone formation.
- To achieve an ‘intelligent’ malleable composite for 3D scaffold with match mechanical bone properties. Mechanical properties: compressive/tensile strength, and Young’s modulus close to normal cortical bone (C = 25…50 MPa ; T = 5…10 MPa ; E = 15…20 GPa) it should maintain while new bone formation and macroporosity Between 200-400 μm to allow for nutrient transport as well as the tailoring of polymer surface chemistry for biological recognition.
- Genetic analysis of the processes controlling bone regeneration. The objective is to understand the temporal and spatial organization of bone regeneration occurring in fracture repair and to use this understanding to inform the engineering of novel scaffolding materials.
- Increase the potential medical applications. The main application targeted concern large lost of segments of bone in order to increase the rate of new bone formation but this knowledge could be apply to other skeletal defects (cartilages,..).