Markerats

Markerats are engineered biocompatible particles used to label and track cells in biomedical research. They are designed to persist within cells or mark them temporarily, enabling observation of migration, division, and fate with non-genetic methods. The term markerat appears in reviews and product literature to distinguish these tools from genetic reporters.

Two principal varieties exist: fluorescent markerats, which carry dyes or quantum-dot–like moieties that emit distinct wavelengths, and magnetically responsive markerats, which incorporate superparamagnetic cores for MRI or related imaging. Most designs feature a core material, a biocompatible shell, and surface ligands that modulate uptake and circulation time.

Synthesis commonly involves nanoparticle fabrication followed by surface modification to render the particle stable in biological fluids, minimize toxicity, and prevent rapid clearance by the immune system. Markerats can be tailored for broad labeling or targeted to specific cell types, and signals can be multiplexed using variants that emit different colors.

Applications include lineage tracing in development, monitoring stem cell therapies, tracking immune cell trafficking, and studies of the tumor microenvironment. Compared with genetic reporters, markerats provide a non-genetic labeling option and can be used where genetic modification is impractical.

Limitations include signal dilution with cell division, potential perturbation of cell behavior, and variable uptake across cell types. Magnetic markerats may accumulate in the liver and spleen, raising safety considerations for clinical translation. Researchers emphasize thorough biocompatibility assessment and dosing.

The term markerat emerged in the 2000s in conference abstracts and early reviews. Development and refinement continued into the 2010s and 2020s, with advances in particle chemistry improving brightness, stability, and targeting capabilities.

See also: cell labeling, fluorescent nanoparticles, magnetic nanoparticles, contrast agents.