Archive for the ‘cell culture’ tag
Levitating Cells
Having spent a few years working on cell based assays for screening small molecules I became aware of how limited traditional in vitro cell culture can be in modeling biological systems. Traditional tissue culture while fairly easy to do and manipulate for experiments, often produces two-dimensional growth with gene expression, signaling, and morphology that can be dramatically different from those found in vivo. This can make in vitro studies clinically irrelevant. In vivo work while a more accurate model has it’s own drawbacks such as cost and ease of manipulation. Therefore, it would be ideal to develop methods which can make in vitro tissue culture produce in vivo results.
That aim is what makes this paper by Souza et al. in Nature Nanotechnology so impressive to me. In this paper they describe a method for culturing cells three-dimensionally by magnetically levitating cells grown in the presence of a hydrogel consisting of gold, magnetic iron oxide nanoparticles, and filamentous bacteriophage.
Dr. Souza’s group tested their hydrogel with glioblastoma cells as seen in the figure above. Application of a magnetic field allows the cells to counteract gravity floating in the media and allowing for three-dimensional growth. The field also concentrated cells resulting in cell to cell interactions consistent with previous work on tissue engineering scaffolds designed to provide a cell growth advantage. In addition, the shape of the magnetic field can also be used to shape cell growth.
While the ability to promote three-dimensional growth without biodegradable porous scaffolds or protein matrixes is remarkable, the truly impressive part of this technique is that the cells exhibit differential protein expression that more closely resembles that of in vivo tumor xenografts as seen in the figure below thanks to their new growth conditions. 
The ability of these three-dimensional cultures to mimic in vivo samples effectively is remarkable and the simplicity of this technology could provide a less time intensive and cost effective solution to traditional experimental methods. It’d certainly be nice to someday be able to design in vitro assays which produce truly clinically relevant data. Maybe with techniques like this one we’ll be able to accomplish that soon.
(Source – Nature Nanotechnology : Three-dimensional tissue culture based on magnetic cell levitation)