(Nanowerk News) The effectiveness of microrobots in assisting drug delivery into cells is currently limited, which affects their therapeutic value. To address this, researchers have integrated a cancer-targeting compound, folic acid (FA), into a microrobot. This allows for increased drug uptake by cancer cells through a process known as receptor-ligand-mediated endocytosis. As a result, the researchers developed a drug delivery system that can pinpoint the area of a lesion using a magnetic field and deliver drugs directly into the cytoplasm of cells via endocytosis.
These findings were published in Journal of Cyborg Systems and Bionics (“Magnetic Microrobots with Folate Targeting for Drug Delivery”).
Microrobots, which are untethered, have demonstrated impressive capabilities in areas such as minimally invasive surgery, drug delivery, environmental cleaning and tissue engineering. One common way to propel these microrobots is through magnetic fields, which offer security, deep tissue penetration, and excellent temporal and spatial control. However, when delivering drugs, these microrobots can only distribute drugs around the cells, but not assist their entry into cells. This limitation may reduce the effectiveness of the treatment, as the drug may not reach the desired target in cells.
To increase drug efficiency, microrobots must have precise targeting capabilities. To this end, the researchers loaded folic acid into the microrobot to enhance cancer cell targeting and drug uptake by cells. Overexpression of FR in cancer cells allows FA to facilitate drug uptake via receptor-ligand-mediated endocytosis.
The engineered magnetic microrobot system comprises biodegradable gelatin methacryloyl (GelMA)-based ABF microhelixes and FA-loaded (email protected) nanoparticles (MOF). Therapeutic drugs such as DOX can be incorporated into microrobot hydrogel networks for cancer treatment. With an external rotating magnetic field, the microrobot can be guided and positioned at the lesion site to concentrate therapeutic drugs around cells. Complete binding of FA to the microrobot and FR to the surface of the cancer cell can trigger endocytosis, allowing MOF(FA) and DOX to enter the cell. Centralizing the microrobots near cells enhances receptor-ligand interactions and improves therapeutic efficiency.
The study showed that microrobots with FA inhibited cell growth more significantly than robots without FA. Therefore, the ABF-MOF(FA) drug delivery system, combining magnetic manipulation with active targeting of FA, shows promising potential for cancer treatment.
The drug encapsulation and release capabilities were tested with the release curve, indicating that the GelMA-based microrobot has these capabilities. The targeting ability of FA was confirmed by the MTT assay and on/off staining experiments. Furthermore, motion control and cell experiments show that microrobots can be precisely controlled by magnetic fields to perform certain tasks. Ultimately, DOX-targeting and folate-targeting magnetic microrobots exhibited significant anticancer effects within 24 hours of being guided to a location determined by a magnetic field.
This folate-targeting magnetic microrobot system holds great promise in cancer treatment, given its high drug loading capacity, navigational control, and enhanced cancer cell targeting and inhibition capabilities.