Rapid Bone Graft Synthesis Through Dual Piezoelectric/Nanomechaniocal Stimulation

点击翻译按钮获取中文摘要

Bone graft is regularly used in surgery (plastics, maxillofacial surgery and orthopaedics); bone is actually the second most grafted tissue after blood. Ideally the surgeon wishes to take bone from one area (donor site) to another area (recipient site) to support the operation they are performing or to replace damaged, infected or cancerous tissue . However, a patient's own donor bone is in short supply and its removal can lead to complications at the donor site. This means the surgeon will often recourse to allograft - decellularised (and thus biologically inferior) - bone from cadavers or other people. A third, and growing, option is synthetic graft. Synthetic graft can be made from biologically active materials, but is not viable at the time of implantation and thus not yet as good as living bone, as cells must be made to infiltrate the material prior to regeneration. It has been known for many decades that bone tissue responds to mechanical loading and commonly, mechanical loading via a bioreactor device is employed to enhanced bone formation in vitro. Recently, it has been also discovered that cells respond to nanoscale mechanical stimulation, and in particular, that nanoscale vibrations induce rapid bone formation from cells cultured in vitro. Interestingly, bone tissue produces minute electrical fields when loaded, a phenomenon which is hypothesised to help with the bone remodelling process during regeneration. However, if this electrical stimulation is important for the rapid generation of bone graft is not yet known and is a focus of this project. Our bioreactor, that supplies nanoscale 'kicks' to cells in culture can be used to convert mesenchymal stem cells (the stem cells of the bone, simple to isolate from a patient's iliac crest or fat tissue) to bone forming osteoblasts. We will optimise this by designing new 3D architectures for the cells to grow in that work in synergy with the bioreactor. The scaffolds will emit physiological electrical signals that the body uses as cues to heal bone. Further, we will look at the biological building blocks, metabolites, that the cells use to form bone and incorporate these into delivery systems that also work with the bioreactor. The electricity produced by the scaffolds will trigger release of the metabolites, further driving bone formation.This will ultimately allow us to improve the quality of living bone graft derived from a patient's own cells while reducing the lab time we need to make it.