The most recent trends for the development of several in vitro cell cultures have been oriented towards the cell immobilisation in 3-dimensional scaffolds and cell encapsulation. In fact, an important requirement of cell survival is self-assembly in functional communities, in the presence of an artificial extracellular matrix. In our research, a previously described technique for spermatozoa encapsulation was applied to obtain capsules loaded with an opaque agent as a model, and to perform a formulative study. A process variable, barium ion concentration, was correlated to some capsule properties, such as weight, gel thickness, total and core diameter. Ion concentration can be modified to obtain capsules with predictable characteristics.