Photopatternable Magnetic Hollowbots by Nd-Fe-B Nanocomposite for Potential Targeted Drug Delivery Applications

Abstract

In contrast to traditional drug administration, targeted drug delivery can prolong, localize, target and have a protected drug interaction with the diseased tissue. Drug delivery carriers, such as polymeric micelles, liposomes, dendrimers, nanotubes, and so on, are hard to scale-up, costly, and have short shelf life. Here we show the novel fabrication and characterization of photopatternable magnetic hollow microrobots that can potentially be utilized in microfluidics and drug delivery applications. These magnetic hollowbots can be fabricated using standard ultraviolet (UV) lithography with low cost and easily accessible equipment, which results in them being easy to scale up, and inexpensive to fabricate. Contact-free actuation of freestanding magnetic hollowbots were demonstrated by using an applied 900 G external magnetic field to achieve the movement control in an aqueous environment. According to the movement clip, the average speed of the magnetic hollowbots was estimated to be 1.9 mm/s.

External Field‐Driven Untethered Microrobots for Targeted Cargo Delivery

“…fabricated a self‐folded microrobot using E‐dent 400 photoresist as the scaffold material and NdFeB MNPs as the magnetic material, which can change from a planar structure to a 3D helical structure. [ 27c ] Drugs were connected to the surface of the microrobot in the form of a non‐covalent hydrogen bond by means of PDA, which can be broken under US stimulation (Figure 16B). More than 90% of the drug was released from the helical microrobot after 1 min of US stimulation, which demonstrated the high efficiency of US‐controlled drug release.…”

“…Reproduced with permission. [ 27c ] Copyright 2020, Elsevier B.V. C) Liquid drug manipulation of the microrobot under acoustic excitation: carrying, releasing, and penetrating. Reproduced with permission.…”

“…The fabrication process of this method includes multiple steps, and the detailed process can be referred to the relevant references. [ 18a,24,27c ] However, the process of such a fabrication method is cumbersome and it is difficult to achieve sophisticated 3D structures, such as double‐helix and cellular scaffold structures. To obtain 3D structures of micron or nanometer size with high fidelity and high precision, many researchers have adopted TPP technology [ 95 ] as the fabrication method of UMRs.…”

“…However, SPIONs have relatively weaker magnetization properties, which means that a stronger external magnetic field is required to actuate microsized UMRs. Despite with many advantages aforementioned, SPIONs are not the only choice, and there are many other magnetic materials used for magnetic actuation in literature such as neodymium‐iron‐boron (NdFeB), [ 27 ] Nickel (Ni) film, [ 28 ] cobalt (Co)‐based alloys, [ 29 ] etc. Ni and Co are usually sputtered on the surface of UMRs as nanofilm coatings, but they are toxic and nonbiocompatible materials.…”

Recent Advances on Nanocomposite Resists With Design Functionality for Lithographic Microfabrication

“…This makes SU-8 the preferred choice for high aspect ratio lithography and for the fabrication of polymeric structural components (Campo and Greiner, 2007). SU-8 has been repeatedly modified for different purposes through the incorporation of molecular additives and NFs (Dutoit et al, 1999;Jiguet et al, 2004;Damean et al, 2005;Jiguet et al, 2005;Jiguet et al, 2006a;Chiamori et al, 2008;Dawan et al, 2008;Mionic et al, 2009;Fischer et al, 2015;Kandpal et al, 2015;Li et al, 2018;Nguyen et al, 2018;Perry et al, 2019).…”