- M.Sc. 1980 (Leningrad/St. Petersburg Polytechnical Institute)
- M.Sc. 1987 (Haifa, Technion)
- Ph.D. 1992 (Haifa, Technion)
The field of Biomaterials is becoming one of the most intellectually exciting and challenging areas of materials engineering that targets not only human body repair but also science and technology in general. Our research is focused on the design of novel Biomaterials and implantable devices, mainly for hard tissue replacement, and on development of new technologies for their fabrication and surface modification.
- Bioresorbable implants are an attractive alternative to metal bone healing devices. Still, the mechanical behavior of state-of-the-art resorbable materials (typically polyester polymers, either neat or reinforced with small amounts of calcium phosphate (CaP) ceramics) falls far short of the expected performance in high-load bearing situations. Replicating some features of nacre – a strong and tough natural nanocomposite with a high content of brittle inorganic phase, can pave the way for a new generation of high-strength resorbable bone implants. In our group, we concentrate on the processing of such “bio-inspired” nanocomposites where CaP ceramic skeleton is toughened by a small amount of continuously dispersed ductile biodegradable component (polymer or Fe/Mg metal). Manipulating the adhesion at ceramic/ductile nanocomponent interface further improves the mechanical properties. An original high pressure consolidation method is employed to fabricate dense nanocomposites without exposure to high processing temperatures. This allows for incorporation of biomolecules that can then be released from the implant to enhance bone regeneration (growth factors) or prevent infection (antibacterial drugs). The resorbable CaP-based nanocomposites being developed can be used in the bulk form (e.g. fixation plates) or for the fabrication of highly porous bone graft substitutes.
- Another research direction is the design and synthesis of high-load-bearing bone scaffolds from shape-memory NiTi alloy resembling the structure of spongy bone (“trabecular Nitinol”) by PIRAC (Powder Immersion Reaction Assisted Coating) conversion of Ni foams having regular interconnected porosity. To help biology regenerate bone tissue, NiTi scaffolds are combined with specially designed delivery matrices (e.g. biomimetic CaP coatings or sol-gel bioglass) for biologically active molecules and proteins.
- PIRAC nitriding method for coating complex-shape metal implants with a hard TiN ceramic layer was developed with the goal to improve wear behavior of joint replacements (JR). Periprosthetic osteolysis in response to wear debris is considered the main cause of JR failure. The potential of TiN PIRAC coatings to reduce wear of metal-on-polyethylene and metal-on-metal articulations was demonstrated in hip simulation tests and in animal models. The coatings also prevent the release of harmful metal ions (e.g. Ni from NiTi) into body fluids. New applications of PIRAC (also in combination with other coating techniques) are studied.
- One of important objective in biomaterials research is the design of materials that can interact specifically with the biological environment for a given purpose. To this end, we bio-functionalize the surface of biomaterials via attachment of different ligands employing Self-Assembled Monolayers (SAM) as cross-linkers. One example is the grafting of bone-binding RGD peptides onto Ti alloys to improve bone cell adhesion. Another example is the attachment of antibodies to superparamagnetic iron oxide nanoparticles used as target-specific MRI contrast agents.