Mineralised tissues as nanomaterials: analysis by atomic force microscopy

Area of Science:

• Biomaterials Science
• Skeletal Biology
• Nanotechnology

Background:

• Mineralized tissues like bone and dentine comprise collagen fibrils and calcium hydroxyapatite.
• Osteoclasts and osteoblasts are key cells in bone remodeling, involving matrix resorption and synthesis.
• Understanding the native structure of these tissues is crucial for skeletal health.

Purpose of the Study:

• To image the native structure of mineralized tissues, including collagen and mineral phases.
• To determine the size of mineral crystals in bone and dentine.
• To observe collagen structure after matrix resorption and acid treatment.

Main Methods:

• Utilized high-resolution atomic force microscopy (AFM).
• Examined unmodified, fully calcified bone and dentine samples.
• Applied acid treatment and simulated osteoclast-mediated resorption to samples.

Main Results:

• Observed mineral crystals ranging from 225 nm to 1.4 microm in diameter in bone and dentine.
• Visualized D-banded collagen in dentine (after acid treatment) and bone (after resorption).
• Measured axial periodicity of collagen at approximately 67 nm (dentine) and 69 nm (bone).

Conclusions:

• AFM enables detailed imaging of mineralized tissue structure in native samples.
• The study provides insights into collagen and mineral organization in bone and dentine.
• This approach can advance the study of bone diseases such as osteoporosis.