Novel hydrophilic chitosan-polyethylene oxide nanoparticles as protein carriers

TLDR

Hydrophilic nanoparticulate carriers are promising for therapeutic molecule delivery, but existing hydrophobic‑hydrophilic carriers require organic solvents and have limited protein‑loading capacity. The study presents a new approach to prepare nanoparticles composed solely of hydrophilic polymers to overcome these limitations. Nanoparticles are formed by mild ionic gelation at room temperature, mixing aqueous phases of chitosan with a PEO‑PPO diblock copolymer and sodium tripolyphosphate. The resulting particles (200–1000 nm, +20 to +60 mV) can be tuned by CS/PEO‑PPO ratio, and exhibit up to 80 % protein entrapment with sustained release over one week. © 1997 John Wiley & Sons, Inc.

Abstract

Hydrophilic nanoparticulate carriers have important potential applications for the administration of therapeutic molecules. The recently developed hydrophobic-hydrophilic carriers require the use of organic solvents for their preparation and have a limited protein-loading capacity. To address these limitations a new approach for the preparation of nanoparticles made solely of hydrophilic polymers is presented. The preparation technique, based on an ionic gelation process, is extremely mild and involves the mixture of two aqueous phases at room temperature. One phase contains the polysaccharide chitosan (CS) and a diblock copolymer of ethylene oxide and propylene oxide (PEO-PPO) and, the other, contains the polyanion sodium tripolyphosphate (TPP). Size (200–1000 nm) and zeta potential (between +20 mV and +60 mV) of nanoparticles can be conveniently modulated by varying the ratio CS/PEO-PPO. Furthermore, using bovine serum albumin (BSA) as a model protein it was shown that these new nanoparticles have a great protein loading capacity (entrapment efficiency up to 80% of the protein) and provide a continuous release of the entrapped protein for up to 1 week. © 1997 John Wiley & Sons, Inc.