Rational design of polyelectrolyte complexes based on bevacizumab and gellan gum with a surface modified with chitosan

Bevacizumab (BVZ) is an anti-angiogenic monoclonal antibody used to treat diseases such as various types of cancer. However, its parenteral administration causes several side effects and oral administration is limited due to the integrity of these macromolecules in the face of the extreme conditions of the gastrointestinal tract. To overcome these limitations, the study of drug delivery systems becomes a promising strategy to increase the efficiency of BVZ therapeutic delivery. Therefore, it is important that drug delivery systems are meticulously designed and that their physicochemical properties are understood. The objective of the present study was to develop nanoparticles through polyelectrolytic complexation between polysaccharides and polyampholytes, without the use of organic solvents, and to evaluate the influence of pH and molecular weight on particle formation. Different proportions of polymers were tested to obtain the nanoparticles, exhibiting average diameters in the range of 222.6–412.1 nm, zeta potential of −16.3 to −40 mV, and polydispersity index of ∼0.16–0.53. Complexation with chitosan promoted charge inversion (> +40 mV), in addition to increasing particle diameter and association efficiency, ranging from 29 % to approximately 60 %.