Curriculum Vitae

Bioactive Composite Nanofibres, Microspheres and Macroporous Foams for Tissue Engineering and Regeneration

Jonny J Blaker

School of Materials, Materials Science Centre, Manchester University, UK

Abstract
Novel nanocomposite foams have been fabricated using bioactive glasses as particulate phases in polylactide (PLA) foams for applications in bone tissue engineering. These glasses release therapeutic ions that stimulate genetic responses in osteoblastic cells, and can release ions that have antibacterial action. The use of phase separation techniques to form these materials into composite scaffolds as monolithic foams, porous microspheres, as well as porous nanofibres will be discussed. We have developed several techniques to result in macroporous structures with surfaces mimicking the morphology of extra cellular matrix from these materials. A new method will be described that enables the rapid production of porous nanofibres by combining solution blow spinning (SBS) and thermally induced phase separation (TIPS) (SBS-TIPS). SBS can produce nanofibres, analagous to those electrospun from polymers dissolved in suitable solvents, yet with a production rate (per head) circa 100 times faster, and without the need for electric fields. In this work we freeze the nanofibres shortly after their formation, ahead of excessive solvent evaporation, causing phase separation within the nanofibres. The challenge is to move away from membrane-like, 2-D nanofibrillar networks to truly interconnected 3-D nanofibre networks that allow proper cell infiltration. Due to the rapidity of nano-fibre formation in a cryogenic environment, the SBS-TIPS technique allows for the simultaneous inclusion of ice-microspheres, formed from a water spray, which later act as in situ macroporosifiers. Subsequent compression of these ice/nanofibre entanglements followed by freeze-drying, results in bioactive interconnected macroporous scaffolds, themselves formed of porous nanofibres. The technique is expandable to aqueous processing and hybrid sol-gel inorganic-organic based materials.