Hemoglobin-Laden Microcapsules for Simulating Oxygen Dynamics of Biological Tissue

Area of Science:

• Biomedical Engineering
• Materials Science
• Biophysics

Background:

• Hemoglobin (Hb) is crucial for oxygen transport but unstable in biological applications.
• Developing stable Hb-based materials is essential for biomedical research and diagnostics.
• Optical tissue phantoms require materials that accurately mimic physiological optical properties.

Purpose of the Study:

• To develop a novel method for synthesizing stable hemoglobin-laden microcapsules (HbMs).
• To evaluate the oxygen-binding properties and stability of the synthesized HbMs.
• To assess the suitability of HbMs for creating optical tissue-simulating phantoms.

Main Methods:

• One-step synthesis of HbMs using liquid-driven coaxial flow focusing (LDCFF).
• Fabrication of solid HbMs phantoms (SHMPs) by mixing HbMs with silicone resin.
• Characterization of HbMs spectral properties and oxygen transport capabilities.
• Evaluation of SHMPs stability and simulation of tissue oxygen dynamics using a dialysis tube model.

Main Results:

• HbMs were successfully synthesized with a solid core-shell structure, preventing Hb leakage.
• HbMs exhibited gas-binding capacity and oxygen affinity comparable to purified Hb.
• SHMPs demonstrated spectral characteristics similar to oxy-hemoglobin and long-term stability (>25 weeks).
• HbM dispersion effectively simulated tissue oxygen dynamics in a dynamic occlusion test.

Conclusions:

• Microencapsulation of Hb within a semipermeable polymeric shell provides effective protection and stability.
• HbMs are promising for developing advanced optical tissue-simulating phantoms in biomedical fields.
• The LDCFF method offers a viable approach for producing functional HbMs for various applications.