Cross-linked hemoglobin as a potential membrane for an artificial red blood cell

Area of Science:

• Biomaterials Science
• Chemical Engineering
• Biotechnology

Background:

• Hemoglobin-based oxygen carriers (HBOCs) offer potential for blood substitutes.
• Encapsulating hemoglobin in artificial cells could improve stability and reduce toxicity.
• Developing selective membranes is crucial for artificial cell function.

Purpose of the Study:

• To create a cross-linked hemoglobin membrane with selective permeability.
• To evaluate the membrane's ability to retain hemoglobin while allowing small molecule diffusion.
• To assess the feasibility of using such membranes for artificial oxygen-carrying cells.

Main Methods:

• A hemoglobin solution was infused into a polycarbonate support and cross-linked using homobifunctional agents.
• Disuccinimidyl glutarate (DSG), disuccinimidyl suberate (DSS), and disuccinimidyl tartrate (DST) were tested as cross-linkers.
• Permeability studies were conducted using a side-by-side diffusion cell to measure hemoglobin and benzoic acid diffusion.

Main Results:

• Disuccinimidyl glutarate (DSG) formed a hemoglobin-impermeable membrane.
• Optimal cross-linking with DSG required specific concentrations and times (e.g., 4.65 mM for 20 min or 0.46 mM for 60 min).
• Benzoic acid, a small molecule, diffused through the DSG-cross-linked membrane at 87.2% of its buffer diffusion rate.

Conclusions:

• A cross-linked hemoglobin membrane with selective permeability was successfully fabricated.
• The membrane effectively retains hemoglobin while allowing passage of small molecules.
• This membrane technology holds promise for developing artificial cells for oxygen delivery.