Abstract: A novel macroscale, contactless, label-free method to print in situ three-dimensional (3D) particle assemblies of different morphologies and sizes is demonstrated using non-adherent (blood) and adherent (MCF-7 and HUVEC) cells. This method of manipulating particles such as cells or biological moleules does not necessarily require the use of nozzles that can contaminate the cell suspension, or to which cells can adhere. Instead, the intrinsic diamagnetic properties of particles such as cells are used to magnetically manipulate them in situ in a nontoxic paramagnetic medium, creating various shapes such as (a) rectangular bar, (b) three-pointed star, and (c) spheroids of varying sizes. A normal distribution of 3D cell structures is produced when formed through magnetic assembly. The use of this method in co-culturing of different cell lines is also demonstrated.

Abstract: A novel macroscale, contactless, label-free method to print in situ three-dimensional (3D) particle assemblies of different morphologies and sizes is demonstrated using non-adherent (blood) and adherent (MCF-7 and HUVEC) cells. This method of manipulating particles such as cells or biological moleules does not necessarily require the use of nozzles that can contaminate the cell suspension, or to which cells can adhere. Instead, the intrinsic diamagnetic properties of particles such as cells are used to magnetically manipulate them in situ in a nontoxic paramagnetic medium, creating various shapes such as (a) rectangular bar, (b) three-pointed star, and (c) spheroids of varying sizes. A normal distribution of 3D cell structures is produced when formed through magnetic assembly. The use of this method in co-culturing of different cell lines is also demonstrated.

Abstract: A new magnetic carbon nanotube (mCNT) biosensor ink (mbio-ink) that utilizes immobilized capture agents to detect specific target analytes via a simple current response method is presented here, expanding the applications of magnetic carbon nanotubes as biomolecule-sensing nanomaterials. The employment of a magnetic field to print the mbio-ink into electrically conductive networks facilitates its integration with an external circuit via the use of a simple electrode system. When the sensor is connected to an external power source, the reduction in current, caused by an interaction between the capture agents and target analyte, is detected. The rapid detection technique and generic benchtop fabrication method allows for scale up, while the small volumes required and magnet independent electrical measurements renders the mbio-ink attractive for drug screening and disease detection applications.