Macrophage In Vitro and In Vivo Tracking via Anchored Microcapsules

Area of Science:

• Biomaterials Science
• Cellular Therapy
• Nanotechnology

Background:

• Macrophages are promising for targeted drug delivery in personalized medicine.
• Tracking macrophage behavior in vivo is crucial for effective cell-based therapies.
• Existing labeling methods can negatively impact macrophage function.

Purpose of the Study:

• To develop and evaluate biocompatible, fluorescently labeled microcapsules for macrophage tracking.
• To assess the impact of microcapsules on macrophage viability, proliferation, and movement.
• To demonstrate the utility of microcapsules for in vivo cell tracking and ex vivo cargo delivery.

Main Methods:

• Fabrication of 3 μm polyelectrolyte microcapsules labeled with Cy7 and RITC dyes.
• In vitro functional assessment of loaded RAW 264.7 and primary bone marrow-derived macrophages (BMDM).
• In vivo tail vein injection of labeled BMDM and ex vivo/in vivo imaging.

Main Results:

• Microcapsules did not affect macrophage viability, proliferation, or movement at maximal loading (5 capsules/cell).
• Fluorescent detection of labeled cells was possible 24 hours post-injection in vivo.
• Successful delivery of microcapsule-laden BMDM to the liver was achieved, with ~62.5% of injected cells reaching the target.

Conclusions:

• 3 μm fluorescent polyelectrolyte microcapsules are suitable for safe macrophage loading.
• These microcapsules facilitate in vivo cell tracking and ex vivo visualization.
• The developed microcapsules support the advancement of macrophage-based cell therapy protocols for targeted drug delivery.