Bone is a regenerative tissue, with potential for healing provided certain physiological conditions are met for: supporting angiogenesis for tissue restoration; environment osteogenesis for remineralisation by using growth factors/bone morphogenic proteins; supporting bio-mechanical function by load transmission for preventing bone non-union. Absence of one or more factors become apparent when damaged bone stops healing after surgery. During healing processes, overall osteogenicity may be explained by osteoinduction, conduction and integration. BonE-GraphT focussed on promoting osteoinduction/conduction in a new materials engineering concept, where bone-forming mineral is grown with an electrically conducting graphene on a titanium surface, for inducing osteoblast cell response for remineralisation. Deposition of calcium phosphate minerals using ultrafast femtosecond pulsed laser on titanium metal substrate, with/without graphene as an electrically conducting medium, was investigated. Deposited thin film composite materials were analysed for cell proliferation tests to ascertain osteogenic potential for surface modified materials.
Training summary: This fellowship offered opportunity for research training in: advanced biomaterials processing/characterisation, osteogenic characterisation; opportunity for interaction with a Clinician, Prof Giannoudis, trauma/orthopaedic surgeon. Cell characterisation training was supported by Dr Raif, who trained the Fellow in osteoblast cell growth. Materials characterisation support was provided by host institute Research team. Original research findings were presented at conferences/published in peer-reviewed journals.
Emerging Societal Importance: Probability of bone related injury increases with age due to falls, osteoporosis and bone disease. Healing potential of the human body also diminishes with age, demanding research in bone materials for promoting bone healing. Bone failure data from the International Osteoporotic Society is quite compelling in demonstrating risk of bone failure in 50-60 age group (female/males). Main cause of bone failure remains loss of bone mineral density for supporting load-bearing capacity of the body. Combined with increasing obesity, bone-failure related morbidity continues to increase not only within the EU but also in the rest of the developed and emerging economies. Chance of full recovery of a 60+ year old patient suffering from acute osteoporosis, after trauma reduces dramatically to less than 25%. Over 300,000 hospital admissions occurred in 2017 in UK due to poor bone stock in frail patients. Frailty based bone injury may be prevented via tissue augmentation and via increased osteoinduction and conduction for remineralisation which has been investigated in BonE-GraphT as a solution for bone-compromised patients. The research is continuing since the BonE-GraphT ended for developing a new paradigm for treating osteoporotic patients.
Main research training objectives for realising research impact were:
1. To develop osteoconductive/inductive surface on titanium alloys, widely used for implant/post-surgery fracture fixation. It is essential that such materials are non-toxic, mechanically robust in the human body. Thus, studying coating of Ti-alloys with osteogenic surface via novel cost-compatible techniques will help to develop implants for compromised patients.
2. Research training demonstrated that pulsed laser deposition of HAp films on Ti-alloy & formation of graphene as a compatible surface is possible for surface engineering of implant materials. Such materials were successfully tested for osteo-induction/conduction.
3. Research also offered opportunity for bringing together novel tools for materials characterisation/understanding of 2D-materials growth on metal & inorganic glass surface for range of sensing/light-generation device applications, which may be compatible with bio-implants. Deposition of 2D-MoS2 materials were studied for light emission properties. A long-term objective is to design osteoconductive/inductive bone implants with integrated light-based sensor for monitoring healing processes
