Currently, most of the drugs developed are first tested on 2-D cell cultures grown under standard laboratory conditions in Petri dishes or flasks. But these cultures vary greatly from the human body tissues that grow 3-dimensionally, in more complex environments within the body. Now, researchers at the University of Durham have developed a unique technology to produce a 3-D matrix that allows stem cells and other living tissue to grow three-dimensionally, invitro.

Studies conducted by the scientists also demonstrated that a highly porous polystyrene scaffold is a more realistic and cheaper way of culturing cells in a 3-dimensional manner, compared to the traditional flat surface Petri plate. They are now planning to develop and commercialize the new technology through ReInnervate Limited, a spinout from the university.

Maria Bokhari, a senior researcher at the School of Biological and Biomedical Science, Durham University, and colleagues (Journal of Anatomy, 2007) evaluated the toxic effects of the anticancer drug, Methotrexate, in both 2-D and 3-D liver cultures. They found that the hepatic cells grown using the 3-D polystyrene scaffold were more similar morphologically and functionally to liver cells found in the human body than the cells grown on 2-D standard plastic wares. The 3-D cell cultures also exhibited less susceptibility to cell death at higher concentrations of cytotoxins compared to the 2-D cell cultures. They also evaluated the growth of 10 different tissue types on the scaffold, including bone, liver, fat and stem cells from bone marrow, and concluded that the novel 3-D cell-growth technology could have very wide applications in toxicity testing and drug screening.

The discovery of the Petri dish in 1877 by Julius Petri, an assistant to Robert Koch, transformed the ability to culture, manipulate, and analyze cells. The difficulty in replicating the insitu environment of a cell, during invitro growth, is one of the major drawbacks of using Petri dishes for culturing cells. Recently, a group of biomedical engineers invented a 3-D Petri dish that allows the cells to assemble 3-dimensionally to form bits of “microtissue” with natural cell-to- cell connections. A team led by Jeffrey Morgan, Professor of Medical Science and Engineering at Brown University, used water-based, non-adhesive agarose gel for creating the new 3-D Petri dish. This 3-D Petri dish contained 820 tiny recesses or wells at the bottom and these wells allowed the cells to settle at the base. The close quarters make the cells pile up and self-assemble to form natural cell-to-cell connections. The scientists also claimed that the new method is a fast, easy, and inexpensive way of creating microtissues.

The new invitro 3-D culturing methods, which are more similar to the invivo system, holds potential to aid in drug development, and make it a cheaper and easier process. It may also help to reduce the need for testing on animals.

Referencess

1. Durham University News. Cell growth technology promises more successful drug development. Durham Univ. Last accessed on September 27, 2007.

2. Bokhari M, Carnachan RS, Cameron NR, et al. Culture of HepG2 liver cells on three dimensional polystyrene scaffolds enhances cell structure and function during toxicological challenge. Journal of Anatomy. 2007 October; 211 (4): 567–576.

3. Brown Scientists Take the Petri Dish to New Dimensions. Brown University News. Brown University. Last accessed on September 27, 2007.