Spatial polarimetric second harmonic generation evaluation of collagen in a hypophosphatasia mouse model.

Polarization-resolved second harmonic generation (pSHG) is a label-free method that has been used in a range of tissue types to describe collagen orientation. In this work, we develop pSHG analysis techniques for investigating cranial bone collagen assembly defects occurring in a mouse model of hypophosphatasia (HPP), a metabolic bone disease characterized by a lack of bone mineralization. After observing differences in bone collagen lamellar sheet structures using scanning electron microscopy, we found similar alterations with pSHG between the healthy and HPP mouse collagen lamellar sheet organization.

Compromised Muscle Properties in a Severe Hypophosphatasia Murine Model.

Hypophosphatasia (HPP) is a rare metabolic bone disorder characterized by low levels of tissue non-specific alkaline phosphatase (TNAP) that causes under-mineralization of the bone, leading to bone deformity and fractures. In addition, patients often present with chronic muscle pain, reduced muscle strength, and an altered gait. In this work, we explored dynamic muscle function in a homozygous TNAP knockout mouse model of severe juvenile onset HPP.

Second harmonic generation characterization of collagen in whole bone.

Bone is a unique biological composite material made up of a highly structured collagen mesh matrix and mineral deposits. Although mineral provides stiffness, collagen's secondary organization provides a critical role in bone elasticity. Here, we performed polarimetric analysis of bone collagen fibers using second harmonic generation (SHG) imaging to evaluate lamella sheets and collagen fiber integrity in intact cranial bone.