A Comparison of Iron Oxide Particles and Silica Particles for Tracking Organ Recellularization

Area of Science:

• Regenerative Medicine
• Biomedical Imaging
• Tissue Engineering

Background:

• Decellularized organ scaffolds offer a promising approach to eliminate graft-versus-host disease in transplantation.
• Tracking cell engraftment within these scaffolds is crucial for successful tissue regeneration.

Purpose of the Study:

• To evaluate the efficacy of ultrasound imaging and magnetic resonance imaging (MRI) in monitoring the reseeding of decellularized murine liver scaffolds.
• To compare the tracking capabilities of silica-labeled versus iron-labeled hepatocytes within these scaffolds.

Main Methods:

• Murine liver scaffolds were decellularized and reperfused with either silica-labeled or iron-labeled hepatocytes.
• Reseeded livers were longitudinally analyzed using ultrasound imaging and MRI.
• Confocal microscopy and scanning electron microscopy were used for detailed imaging of liver biopsies.

Main Results:

• MRI demonstrated a lower detection limit (0.08 mg/mL) compared to ultrasound imaging (0.28 mg/mL).
• Silica-labeled cells exhibited slower proliferation rates than iron-labeled cells.
• Both ultrasound and MRI successfully tracked longitudinal recellularization, despite underestimating cell numbers compared to scanning electron microscopy.

Conclusions:

• Ultrasound imaging and MRI are viable tools for monitoring liver scaffold recellularization.
• Iron-labeled cells may offer advantages in proliferation for regenerative applications.
• Further optimization of imaging resolution is needed for precise cell quantification.