Protein crystals for the delivery of biopharmaceuticals

Abstract

The year 2002 marked the 20th anniversary of the first successful product of modern biotechnology, the regulatory approval of recombinant insulin for biopharmaceutical applications. Insulin is also the first crystalline protein to be approved for therapeutic use. Over the past two decades, almost 150 biopharmaceuticals have gained marketing authorisation; however, insulin remains the only crystalline protein on the market. Significant research and development efforts have focused on the engineering of protein molecules, efficacy testing, model development, and protein production and characterisation. These advances have dramatically boosted the therapeutic applications of proteins, which now include treatments against acute conditions, such as cancer, cardiovascular disease and viral disease, and chronic conditions, such as diabetes, growth hormone deficiency, haemophilia, arthritis, psoriasis and Crohn's disease. Despite these successes, many challenges normally associated with biopharmaceuticals, such as poor stability and limited delivery options, remain. Protein crystals have shown significant benefits in the delivery of biopharmaceuticals to achieve high concentration, low viscosity formulation and controlled release protein delivery. This review will discuss challenges related to the broader utilisation of protein crystals in biopharmaceutical applications, as well as recent advances and valuable new directions that protein crystallisation-based technologies present.

Hyperoxaluria Is Reduced and Nephrocalcinosis Prevented with an Oxalate-Degrading Enzyme in Mice with Hyperoxaluria

“…Recombinant Bacillus subtilis oxalate decarboxylase (EC 4.1.1.2) was expressed in Escherichia coli , purified [11] and processed to crystals of the oxalate decarboxylase, and subsequently cross-linked with glutaraldehyde (OxDc-CLEC®) [12, 13]. This enzyme is a metalloprotein with a broad pH-activity profile from pH 3 to pH 7.…”

Advanced protein crystallization using water-soluble ionic liquids as crystallization additives

“…Furthermore, crystallized proteins may offer superior properties compared to liquid formulations or amorphous lyophilisates due to better handling, longer shelf-life, and higher purity (Schmidt et al 2004). Furthermore, crystalline pharmaceutical proteins may provide the advantageous possibility of controlled slow release of activity (Basu et al 2004). The empirical crystallization methods for structural analysis of proteins have been applied for decades and, consequently, optimized techniques have emerged (Bergfors 1999).…”

Novel Long-Acting Crystal Formulation of Human Growth Hormone

“…In general, crystalline proteins provide many potential advantages, such as improved stability during manufacturing, storage and delivery, ease of handling, and varied formulation and delivery options (11). For example, high-dose, low-viscosity formulations of crystalline antibodies have recently been reported (12).…”