Spheroids as a Type of Three-Dimensional Cell Cultures-Examples of Methods of Preparation and the Most Important Application

Abstract

Cell cultures are very important for testing materials and drugs, and in the examination of cell biology and special cell mechanisms. The most popular models of cell culture are two-dimensional (2D) as monolayers, but this does not mimic the natural cell environment. Cells are mostly deprived of cell-cell and cell-extracellular matrix interactions. A much better in vitro model is three-dimensional (3D) culture. Because many cell lines have the ability to self-assemble, one 3D culturing method is to produce spheroids. There are several systems for culturing cells in spheroids, e.g., hanging drop, scaffolds and hydrogels, and these cultures have their applications in drug and nanoparticles testing, and disease modeling. In this paper we would like to present methods of preparation of spheroids in general and emphasize the most important applications.

Keywords: 3D cell culture; drug testing; spheroids.

Figure 1

Formation of spheroids on MCF-7 cell line.

Figure 2

Spheroid formation in hanging drop method: (A)—cell suspension dispensed; (B)—cells in hanging drop; (C)—cells aggregate to form spheroid [29].

Figure 3

Cell culture in bottle with agitator. Cells start aggregating and self-assembling [9].

Figure 4

Model of hydrogel inverted colloidal crystal (ICC) scaffold [6].

Figure 5

(A) A single 2-lane bioreactor scheme composed of: 1—a gel inlet; 2—a perfusion inlet; 3—an optical readout window; 4—a perfusion outlet; (B) the readout window and its cross section (horizintal view); a phaseguide separates a 2-lane chamber and allows to selective gel patterning; (C) melted gel with cells is loaded and selectively patterned by the phaseguide; (D) after gelation the medium is provided in the perfusion lane and gravitational leveling leads to perfusion between the perfusion inlet and the perfusion outlet wells [78].