Collagen piezoelectricity in osteogenesis imperfecta and its role in intrafibrillar mineralization

Abstract

Intrafibrillar mineralization plays a critical role in attaining desired mechanical properties of bone. It is well known that amorphous calcium phosphate (ACP) infiltrates into the collagen through the gap regions, but its underlying driving force is not understood. Based on the authors’ previous observations that a collagen fibril has higher piezoelectricity at gap regions, it was hypothesized that the piezoelectric heterogeneity of collagen helps ACP infiltration through the gap. To further examine this hypothesis, the collagen piezoelectricity of osteogenesis imperfecta (OI), known as brittle bone disease, is characterized by employing Piezoresponse Force Microscopy (PFM). The OI collagen reveals similar piezoelectricity between gap and overlap regions, implying that losing piezoelectric heterogeneity in OI collagen results in abnormal intrafibrillar mineralization and, accordingly, losing the benefit of mechanical heterogeneity from the fibrillar level. This finding suggests a perspective to explain the ACP infiltration, highlighting the physiological role of collagen piezoelectricity in intrafibrillar mineralization.

Electromechanical Coupling in Collagen Measured under Increasing Relative Humidity

“…Our work provides evidence for the first time on how electromechanical coupling in fibrillar collagen is influenced by the degree of humidity, showing a sustained increase in the piezoresponse when RH < 60%. Collagen piezoelectricity is of great interest in different fields ranging from physics of proteins up to tissue engineering such as biomineralization processes driven by piezoelectric phenomena [42,43].…”

Stem Cell Self‐Triggered Regulation and Differentiation on Polyvinylidene Fluoride Electrospun Nanofibers

“…Bone is a natural piezoelectrical material from an engineering point of view. [1] In normal physiological activities, original bone formation, bone repair, and bone remodeling are accompanied by piezoelectric effects. [2,3] As the composition of bone, osteocytes originate from bone marrowderived mesenchymal stem cells (BMSCs) are mechanosensory cells, and their responses are triggered by externally stimulated cell deformation.…”