Magnetic Nanoparticles Significatnly Speed Up Destruction of Blood Clots

Endovascular clot retrieval might become the standard future treatment for ischemic strokes, thanks to recent research published in the New England Journal of Medicine. While this option may be better than existing clot busting drugs, researchers at the Houston Methodist Research Institute have developed new magnetic nanoparticles that can deliver a high concentration of a drug directly to the clot site, dissolving it orders of magnitude faster than direct injections.

The nanoparticles are made of iron oxide coated with albumin, which cloaks the nanoparticles so that the immune system does not immediately target them. Because the particles are magnetic, they are readily seen under MRI and can be steered using an external magnetic guidance system. Moreover, the same magnet can induce a high frequency vibration of the nanoparticles, heating them up to further help with clot destruction.

The nanoparticles have so far been tested in a laboratory environment involving mice and human blood, while the cargo ferried was the commonly used thrombolytic tPA (tissue plasminogen activator).

From the study abstract in Advanced Functional Materials:

In vitro, as compared to free tPA, the proposed nanoconstructs demonstrate a ≈100-fold increase in dissolution rate, possibly because of a more intimate interaction of tPA with the fibrin network. The clot dissolution rate is further enhanced (≈10-fold) by mild, localized heating resulting from the exposure of tPA–NCs to AMF. Intravital microscopy experiments demonstrate blood vessel reperfusion within a few minutes post tail vein injection of tPA–NCs. The proposed nanoconstructs also exhibit high transverse relaxivity (>400 × 10^–3 m⁻¹ s⁻¹) for magnetic resonance imaging. The multifunctional properties and the 3 orders of magnitude enhancement in clot dissolution make tPA–NCs a promising nano-theranosis agent in thrombotic disease.

Study in Advanced Functional Materials: TPA Immobilization on Iron Oxide Nanocubes and Localized Magnetic Hyperthermia Accelerate Blood Clot Lysis…

Houston Methodist: Magnetic nanoparticles could stop blood clot-caused strokes…