Albumin-based potential drugs: focus on half-life extension and nanoparticle preparation

Albumin has been viewed as one of the most useful and versatile carrier proteins in pharmaceutical and clinical fields. Albumin is biocompatible and non-toxic, and so can be used as a pharmaceutical carrier more safely versus many synthetic polymers. Importantly, albumin has great ability to extend circulating half-lives of short-lived peptides and protein drugs when they are properly linked because albumin is hardly filtered in the glomerulus due to its large size (~66.4 kDa). Albumin is also an excellent material to construct nanoparticles because it has good physicochemical stability, targetability, and chemical functionality. In the first part of this review, three major methods for half-life extension of peptide/protein drugs using endogenous or exogenous albumin are described: physical non-covalent binding, covalent binding, and albumin-fusion. The second part details the most intensively utilized methods for nanoparticle preparation: desolvation, nanoparticle albumin bound (Nab™) technology, and self-assembly. The review provides in-depth understanding for albumin-based drugs and their nano-delivery.