Deadline: Applications will be accepted at any time until the position is filled.

Skeletal tissue loss as a result of injury or disease causes a significantly reduced quality of life at significant socioeconomic cost. Fractures alone cost the European economy €17 billion and the US economy $20 billion annually. In the US, there are some 8 million bone fractures of which approximately 5% to 10% are associated with delayed healing or non-union; while, each year in the UK there are some 150,000 wrist, vertebral and hip fractures due to osteoporosis with an estimated healthcare cost, in the UK alone, of £2.1 billion per annum. Between 30 and 50% of hip replacement surgeries will require subsequent revision, a procedure that often requires an additional source of bone graft material to augment host bone stock and to promote the integration of the implant with the native bone. None of current solutions can satisfy this urgent need in an increasing ageing population. We propose the use of alternative ‘tissue engineering’ strategies to address this need. Here, a material scaffold is designed and 3D printed as a template to actively stimulate tissue in growth and replacement, which will be combined with a source of implantable human skeletal stem cells to create an artificial, three-dimensional tissue replacement.

The problem of currently 3D printing technologies is the lack of capacity to make one scaffold with multiple materials to achieve multiple properties/functions in a complex system. In an ideal tissue engineering scaffold, it should provide not only proper controlled hierarchical structures for cell differential/blood vessel angiogeneisis/nerve conductivity, but also proper mechanical, chemical and physiological properties for different tissues regeneration and local growth factor delivery. Scaffold made from one materials or one composite could not provide all of the functions. In this proposal, a novel multiple-material additive manufacturing (MMAM) system is proposed in which ultrasonic controlled fine nozzles will be used to “drop-on-demand” dispense multiple materials in any 3D spatial location, in order to integrate multiple functions and properties as well as to produce functionally graded parts during Additive Manufacturing (AM). This will bring about a step change for the next generation of AM for advanced design and manufacturing in which both the structure and other functions can be manufactured in one process. 

Preliminary research led by Dr. Yang and Prof. R. Oreffo have shown that the novel scaffold fabrication method combined with stem cell seeding has shown very promising results. Based on these initial results, this project aims to realise a novel 3D printing to print multiple materials scaffold with stem cell.