Advancing Biomineralization Research with Liquid Transmission Electron Microscopy

Biomineralization is a crucial process in the formation and maintenance of hard tissues and the integration of biomedical devices, yet its mechanisms remain elusive due to the limitations of traditional electron microscopy techniques which often involve static, dehydrated, or frozen samples. This talk will present new liquid transmission electron microscopy (liquid-EM) methodologies that overcome these limitations by enabling the visualization of mineralization processes in their native liquid environments. Thin-film enclosures and flow cells were used to explore collagen mineralization in the presence of a calcium phosphate and polyaspartic acid solution, capturing the progressive crystallization of mineral particles and eventual attachment along collagen fibrils. The findings, which capture non-classical crystallization in real time, align well with findings using cryo-TEM. Further, a new method combining the nanofabrication of titanium lamellae by focused ion beam microscopy with in situ liquid-EM to investigate calcium phosphate-titanium interfacial mineralization will be introduced. This technique revealed multiphasic CaP particles nucleating, adhering, and assembling on and around titanium surfaces. This highlights the potential of liquid-TEM to explore nanoscale interactions between biomaterials and liquids as a platform for enhancing implant osseointegration and developing new treatments for mineralized tissue diseases. Other applications of advanced electron microscopy for understanding biomineralization will be highlighted.