Protein–Polyanion Interactions for the Controlled Release of Monoclonal Antibodies

Abstract

The objective of the present study was to investigate ionic interactions between alginate and a monoclonal antibody (mAb1) and to utilize those interactions for the sustained release of mAb1. The existence of ionic interactions between alginate and mAb1 was strongly reflected by their rheological behavior. A 3-4 times increase in storage modulus (G') was observed by addition of 30 mg/mL mAb1 to a 20 mg/mL alginate solution. This increase was strongly dependent on pH and ionic strength. In vitro release studies revealed a marked pH-dependence of release rates and the reversibility of alginate-mAb1 complexation under physiological conditions. Two alginate-mAb1 sustained release formulations were developed by an internal gelation technique using CaCO(3) and CaHPO(4) as calcium sources for physical cross-linking. The CaCO(3) formulation provided a stable pH-environment, optimally suited for pH-sensitive proteins. CaHPO(4) led to a lower pH and stronger alginate-mAb1 interactions. The CaHPO(4) cross-linked alginate released mAb1 over a period of 10-15 days. The long release period and changes in viscoelastic properties of alginate, when being mixed with mAb1, indicate the incorporation of mAb1 molecules into a mixed network with alginate. The results of this study demonstrate that ionic interactions between polyanions and mAb1 are present and that they can be exploited for sustained release delivery of mAb1.

Overcoming the challenges in administering biopharmaceuticals: formulation and delivery strategies

“…In another example, an alginate depot formulation of a fully humanized immunoglobulin G1 (IgG1) monoclonal antibody was developed to exploit the electrostatic interactions that occur between the protein and the polyanionic gel matrix to enable local sustained delivery 52,53 . The system was designed to provide a stable pH environment and to avoid protein aggregation at a high payload concentration.…”

Buffer‐free therapeutic antibody preparations provide a viable alternative to conventionally buffered solutions: From protein buffer capacity prediction to bioprocess applications

“…For example, Schweizer, et al, reported that mAb buffer capacity can influence chemical reactions. [6] They found that mAb concentration, through its impact on the reaction solution's pH, influenced formation of an alginate-mAb sustained-release formulation.…”

Synthetic Biomaterials from Metabolically Derived Synthons

“…164–167 Hydrogels are prepared using naturally occurring polymers [cellulose, 168 hyaluronan, 169 alginate, 170 etc. ), synthetic materials (poly(vinyl alcohol), 171 poly(ethylene glycol), 172,173 poly(2-hydroxyethyl methacrylate), 174,175 etc.]…”