Acid-etching technique of non-decalcified bone samples for visualizing osteocyte-lacuno-canalicular network using...

Area of Science:

• Biomaterials Science
• Bone Biology
• Microscopy Techniques

Background:

• The osteocyte lacuno-canalicular network (LCN) is crucial for bone cell communication and nutrient transport.
• Visualizing the LCN is challenging due to bone's dense structure and the need for specialized preparation techniques.
• Scanning electron microscopy (SEM) offers high-resolution imaging but requires specific sample preparation for delicate microstructures.

Purpose of the Study:

• To establish an optimal acid-etching protocol for polymethyl methacrylate (PMMA)-embedded bone samples.
• To enable clear visualization of the osteocyte lacuno-canalicular network (LCN) using SEM.
• To provide a method for studying bone microarchitecture and its relation to metabolic activity.

Main Methods:

• Human jaw bone samples (N=18) were collected and fixed in 70% ethanol.
• Non-decalcified bone samples were embedded in polymethyl methacrylate (PMMA).
• PMMA-embedded specimens underwent acid-etching with 9% or 37% phosphoric acid (PA) followed by SEM analysis.

Main Results:

• Acid-etching with 9% phosphoric acid provided the most informative and favorable visualization of the LCN.
• Initial etching durations of 30-40 seconds are recommended for optimizing the protocol.
• SEM imaging revealed detailed morphology of osteocytes and the LCN in prepared samples.

Conclusions:

• The 9% phosphoric acid etching technique is effective for visualizing the LCN in PMMA-embedded bone for SEM.
• This method facilitates the study of bone microstructural changes related to metabolism and disease.
• Optimized etching protocols are essential for high-resolution imaging of the bone's vital network.