Targeting of colloidal particles to the bone marrow

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Drug Delivery Systems

Background:

• Intravenously administered colloidal particles are typically cleared by the liver and spleen.
• Limited particle delivery to the bone marrow restricts its use in diagnostics and therapeutics.

Purpose of the Study:

• To develop a method for enhancing microsphere deposition in the bone marrow.
• To investigate the potential of poloxamer 407 as a coating agent for colloidal particles.

Main Methods:

• Model microspheres were coated with the block co-polymer poloxamer 407.
• The biodistribution of coated microspheres was evaluated, focusing on liver, spleen, and bone marrow uptake.

Main Results:

• Coating with poloxamer 407 significantly reduced uptake by reticuloendothelial cells in the liver and spleen.
• A preferential accumulation of coated microspheres was observed in the bone marrow.

Conclusions:

• Poloxamer 407 coating effectively shields colloidal particles from rapid clearance.
• This approach enables targeted delivery of microspheres to the bone marrow, opening avenues for radiodiagnosis and bone marrow disease treatment.