Date of Award

Fall 9-19-2022

Degree Type


Degree Name

MS Biology




Jessica Cottrell, Ph.D.

Committee Member

Constantine Bitsaksis, Ph.D.

Committee Member

Daniel Brian Nicols, Ph.D.


bone, osteoimmunology, bone homeostasis


Approximately fourteen percent of the human body is composed of bone. The adult human skeleton is made of 206 bones, which make up the internal framework of the body. Osteoblast and Osteoclast cells are essential in maintaining the structure and function of bone, for bone homeostasis to occur. Previous data shows that caffeine can potentially have a negative effect on bone homeostasis. Whereas, ZnCl2 has been found to have a positive effect on bone homeostasis in controlled doses. Published data for treatments of caffeine and ZnCl2 are inadequate. The goal of this study was to determine the optimal concentration range for these treatments in maintaining bone metabolism. ZnCl2 and caffeine were provided in increasing concentrations to a 3D-bone organoid model (3D-BOM) for 21 days. Treatment concentrations were determined based on WHO/EPA guidelines. Alkaline phosphatase activity and alizarin red staining was completed to assess osteoblast differentiation and function respectively. Data shows that in the concentration range of 3µM-30µM, ZnCl2 maintains alkaline phosphatase activity. 3µM and 10µM ZnCl2 concentrations enhanced calcium deposition while 30µM ZnCl2 showed impairment. Caffeine (0.005µM, 0.01µM and 0.1µM) had negative effects on alkaline phosphatase activity or calcium deposition. Data demonstrates that ZnCl2 and caffeine has concentration-dependent effects on osteoblast differentiation/function. In the future, the effects of trace elements on osteoclast function and gene/protein expression will be evaluated. Determining optimal levels of trace elements for bone metabolism can be used to assess the range of disorders and disease caused by disruption in bone homeostasis.