Role of Mineral Deposition on the Electrical Conductivity of Bone Tissue Constructs.

Because bone is composed of both inorganic hydroxyapatite mineral and an organic collagen scaffold, the use of mineralized constructs has been widely used to develop engineered tissue constructs for the study of the bone structure and physiology. This has been done to generate templates more efficiently for in vitro cell studies. The use of Simulated Body Fluid has been shown to be a reliable tool for the development of the mineral element when used in conjunction with gelatin, collagen, or other protein hydrogels. The resulting mineral coats have morphology and chemistry similar to native tissue. However, because bone possess unique piezoelectric properties, the study of the nature of the conductive additive was studies further. Gelatin methacrylate constructs were coated using Simulated Body fluids, and their electric character tracked as a function of mineral deposition. A novel resistance testing chip developed in house was used for this purpose. Chemically stimulated Saos-2 osteosarcoma cell laden constructs were mineralized in parallel to generate hydrogels with native apatite for comparison. After confirming the chemical and morphological characteristics of each, the testing template was shown to be robust enough to show increases in conductivity when compared to their original baseline, with values like one another once the constructs were fully mineralized. This work can be expanded on now that the efficacy of body fluid applications has been replicated on small scale constructs, and a robust process for creating small cell-produced mineral elements have been explored. Additional work can be carried out to study whether simulated Body Fluid can be used to generate constructs that are piezoelectric in nature