A: Cell culture is a very useful and widely used technique in stem cell research, (bio)pharmaceutical development, cell biology, toxicology, bioengineering and tissue engineering fields for observing and studying cells and their interactions with pharmaceuticals, biological factors and biomaterials in vitro.

A: Conventional cell cultures are conducted in cell culture vessels, such as in 2, 4, 6, 24, 96 well cell culture plates. Cells cultured in these cell culture vessels are grown in cell culture medium in monolayer in a 2-dimensional fashion.

A: While culturing cells in two dimensions (2D) is a convenient method for preparing, observing and studying cells and their interactions with pharmaceuticals, biological factors and biomaterials in vitro, it does not mimic the cell growth fashion in vivo. In real living body, cells are often growing in three dimensional (3D) and building three dimensional living tissues or organs.

A: Emerging evidence showed that 3D cell culture systems in vitro would offer the following advantages

1. Facilitate the understanding of structure–function relationship in normal and pathological tissue conditions. Studies have shown that human annulus disc cells cultured in 3 dimensional gel systems showed different morphology than those cultured in 2D. These cells cultured in 3D showed increased proteoglycan synthesis compared to monolayer grown cells, and formation of multi-celled colonies with extracellular matrix deposited around and between cells. Furthermore, the human annulus disc cells cultured in 3 dimensional showed the evidence of Type I and II collagen production which was not found in mono-layer cell culture.

In vitro animal cell growth in 3D promotes normal epithelial polarity and differentiation. Cells move and divide more quickly and have a characteristically asymmetric shape compared with that of cells in living tissue.

2. 3D cell culture is a better model for studying the interactions between cell and growth factors as well as cell and therapeutic agents. For example, a three dimensional cell culture of cancer cells allows the exploration of many basic questions related to cancer biology, as receptors for tumor development growth factors are expressed in different ways in comparison to the standard 2 dimensional tissue culture plates. For breast cancer, 3 dimensional culture provides a model system for understanding the regulation of cancer cell proliferation and for evaluation of different anticancer drugs. There is a substantial amount of evidence that cells growing in 3D culture are more resistant to cytotoxic agents than cells in monolayer or dispersed culture. Many studies have demonstrated an elevated level of drug resistance of spheroids culture compared with cells in monolayer. Initially, investigators attributed drug resistance of spheroids to poor diffusion of the drugs to interior cells but now it has been proved that only 3 dimensional culture accounts for drug resistance rather than mere inaccessibility to nutrients. Further study confirmed that 3D culture is a better model for the cytotoxic evaluation of anticancer drugs in vitro.

3. 3D cell culture systems in vitro can facilitate the understanding of structure–function relationship in normal and pathological conditions. It is now well accepted that bone and cartilage-derived cells behave differently in 3D than in a 2D environment and that the 3D culture systems in vitro are mimicking the in vivo situation more closely than the 2D cultures. In a recent study, three human osteogenic cell lines and normal human osteogenic (HOST) cells were cultured in 3D hydrogel matrix. It was demonstrated that osteosarcoma cells proliferate as clonogenic spheroids and that HOST colonies survive for at least 3 weeks. Mineralization assay and gene expression analysis of osteoblastic markers and cytokines indicate that all the cells cultured in 3D in this hydrogel matrix exhibited a more mature differentiation status than cells cultured in monolayer on plastic cell culture plates.

4. 3D culture is a better technique for stem cell expansion. Human Embryonic Stem Cells (hESC), when culture in 3D for expansion, showed a much higher cell number after 30 day expansion, compared to 2D expansion in cell culture plate. Expanded hESC are able to differentiate into representatives of the three germ layers: ectoderm, endoderm, and mesoderm.

A: Similar to tissue-engineered scaffolds, the products are fabricated using the state-of-the-art precision micro-fabrication technology. Instead of using biodegradable materials as in tissue engineering, our cell culture scaffolds will be fabricated using non-biodegradable materials with controlled porosity and pore size. Cells will be growing freely throughout the 3D structure of the scaffold, thereby enabling 3D cell culture.

A: 3D Biotek is developing a series of innovative 3D cell culture products to help our customers to achieve the following objectives:

• Reduce animal testing
• Yield more predictive data from in vitro study
• Improve cell culture efficiency
• Increase the production yield of cytokines, antibodies, and other biological molecules.
• Reduce cost and time to identify new drug candidates
• Reduce time to market
  

  As a publication in journal Nature pointed out: the benefits of the technique are so self-evident that little marketing will be needed to persuade the uninitiated to move up a dimension, just as soon as the issues of convenience are resolved.

A: 3D Biotek's products will have the following unique features:

1. Convenient to use - The products are sterilized and ready to use, just like the way of using cell culture dish/plates/flasks. No further preparation is needed.
2. 100% open porosity - The pores of the products are 100% open, therefore, cells can be seeded easily throughout the scaffolds, and the nutrient and cell metabolism waste can be exchanged easily. This feature allows the products particularly useful in conducting dynamic cultures.
3. Well defined pore size and porous structure - 3D Biotek’s precision microfabrication technology produces well-defined porous matrix and ensures the reproducibility of the porous structure from batch to batch.
4. Compatible with trypsin digestion protocol - Cultured cells can be easily harvested by using the same trypsin digestion protocol as in the 2D cell culture.
5. Improved Cell Culture Efficiency - 3D Biotek’s products have increased surface areas as compared to 2D cell culture plates. Therefore, more cells can be cultured using the same size cell culture dish, plates, flasks or bioreactors.
6. Easy separation of cytokines and growth factors secreted by cultured cells - Unlike gel matrix, our 3D cell culture matrix will not absorb cytokines and growth factors. Therefore, cytokines and growth factors, which are secreted by cultured cells during 3D culture, can be easily separated or recovered from culture medium without adding extra separator steps.