Imagine the benefits of knowing exactly which medical treatment works best for each patient. Three-dimensional (3D) cell cultures based on aqueous two-phase systems offer this promising advantage.
This article provides an overview of a technique called the “aqueous two-phase system” and its evolution toward innovative applications, particularly 3D cell cultures—a growing research focus at the Institute for Obesity Research at Tecnológico de Monterrey.
Repurposing established techniques to create new applications is a hallmark of innovation. Such is the case with aqueous two-phase systems, which are now being explored for constructing 3D cell cultures with potential game-changing applications in healthcare.
Aqueous Two-Phase Systems
Let’s start with the basics: what are aqueous two-phase systems, and what have they been used for in the past?
Aqueous two-phase systems (ATPS) composed of polymer-polymer mixtures are employed to separate and extract a product of interest from a complex sample —this method separates two liquid phases formed by two different polymers dissolved in water [1].
This creates a suitable environment for use with biological products [2]. The phase separation occurs due to the incompatibility of the components when mixed in certain proportions [1], similar to what happens when water and oil are combined.
The formation of phases generates two distinct environments, allowing different sample components to migrate to the phase with greater affinity (upper or lower phase) [1].
Traditionally, aqueous two-phase systems have obtained high-value biological products, including proteins, cells, bacteria, yeast, viruses, and more [3].
The versatility of these systems lies in their simplicity of implementation, as they only require basic laboratory materials, making them more cost-effective than traditional three-dimensional (3D) cell culture techniques. The latter demand sophisticated materials such as scaffolds or gels to support 3D cell growth [4].
These advantages have driven efforts to explore new applications of aqueous two-phase systems to generate innovative solutions. Among these, their use has been proposed to develop 3D cultures.
This type of 3D culture enables cells to grow in a more natural environment, simulating in vivo tissue conditions and allowing cells to interact and grow in layers. This is useful for developing more realistic disease models and testing drugs [5].
3D Cultures Using Aqueous Two-Phase Systems
3D cell cultures based on aqueous two-phase polymer systems are created by combining two polymer solutions in water, such as polyethylene glycol (PEG) and dextran.
In the dextran polymer phase, the cells of interest are encapsulated, while polyethylene glycol serves as a coating layer. The cells grow within the sphere that contains them, ensuring cell-to-cell contact, which helps recreate an environment as close to reality as possible by forming more complex and functional structures [6].
By being able to recreate environments similar to those in the body using a technique that only requires basic laboratory equipment, exciting possibilities for innovative applications arise:
Imagine replicating a tumor’s growth using a patient’s cells and testing various treatments to determine the most effective option for that case —or growing fat cells based on an individual’s unique distribution to study different anti-obesity treatments.
Note: The potential for application is vast, so this is one of the research lines being explored within the Bioengineering and Medical Devices Unit at the Institute for Obesity Research, Tecnológico de Monterrey. This project is supported by funding from Basic and Frontier Science programs for its development.
References
- Albertsson, P.-Å., Partition of Cell Particles and Macromolecules in Polymer Two-Phase Systems, in Advances in Protein Chemistry, C.B. Anfinsen, J.T. Edsall, and F.M. Richards, Editors. 1970, Academic Press. p. 309-341.
- González-González, M. and M. Rito-Palomares, Aqueous two-phase systems strategies to establish novel bioprocesses for stem cells recovery. Critical Reviews in Biotechnology, 2014. 34(4): p. 318-327.
- Benavides, J., et al., Extraction and purification of bioproducts and nanoparticles using Aqueous Two-Phase Systems strategies. Chemical Engineering & Technology, 2008. 31(6): p. 838-845.
- Chairez-Cantu, K., M. González-González, and M. Rito-Palomares, Characterization of polymer-polymer aqueous two-phase system droplets for 3D culture future applications. Journal of Chemical Technology & Biotechnology, 2023. 98(8): p. 1888-1895.
- González-González, M. and M. Rito-Palomares, Cell-based aqueous two-phase systems for therapeutics. Journal of Chemical Technology and Biotechnology, 2020. 95(1): p. 8- 10.
- Chairez-Cantu, K., M. González-González, and M. Rito-Palomares, Generation of polyethylene glycol-dextran aqueous two-phase system droplets using different culture media under in vitro conditions. Food and Bioproducts Processing, 2023. 139: p. 157-165.
Author
Mirna González-González, Research Professor at the Bioengineering and Medical Devices Unit of the Institute for Obesity Research at Tecnológico de Monterrey, and leader of the project “A New Approach Using Aqueous Two-Phase Systems for Constructing 3D Adipose Tissue Cultures.”
