 Kytosan is one of the most used polysaccharides in the design of drug delivery strategies for administration of either biomacromolecules or low molecular weight drugs. For these purposes, it is frequently used as matrix-forming material in both nano and micron-sized particles. The demonstration of systems biocompatibility is still in its infancy. This article was authored by Ana Grena, Susana Rodriguez, Carmen Ramón and Lopez, and others.