AL-CS hydrogel beads were formed by coacervation,in which the carboxyl groups of AL electrostaticallyinteract with CS amino groups. CS has a tendency toionize in solutions with acidic pH, since it presents apKa of around 6.5. However, when AL is dissolvedin a neutral pH solution, the carboxyl groupsbecome negatively charged. In aqueous solutionswith a pH between 3.5 and 6.5, the amino groups ofCS interacted with the carboxyl groups of AL, prob-ably by electrostatic interaction or hydrogen bondsto form the polyelectrolyte complex.27–29Accordingto George and Abraham,4the formation of a polye-lectrolyte complex, reduces the porosity of the ma-trix of polymers contributing to a better encapsula-tion of bioactive compounds. In this study, weformed these hydrogels for biotechnological applica-tion studies as carriers in controlled delivery sys-tems for b-lap, an antitumor drug.