Purification of antileukemic drugs using functionalized nanomaterials

Abstract

Acute lymphoblastic leukemia (ALL) accounts with approximately 5,000 new cases in the United States and 4,000 in Europe each year [1]. The first-line biopharmaceutical being used to treat acute ALL, Oncaspar, is based on L-asparaginase (LA), and accounts with approximately USD $100 million in annual sales [2]. Its purification accounts for up to 80% of its total production cost [3], and therefore, it is crucial to find new strategies to purify LA in order to decrease its current cost and allow their routinely use by a widespread population. This work aims the development of a cost-effective technology based on nanomaterials to purify LA from the fermentation medium, which is rich in other proteins. In this study, it was developed reusable functionalized nanomaterials, namely carbon nanomaterials (CNTs), which are able to establish (non-covalent) specific interactions with LA, allowing therefore its purification from the fermentation broth in which it is produced. Commercial LA was used in a first set of studies in order to understand the adsorption behavior of the enzyme over CNTs. Different CNTs and experimental conditions, such as pH, contact time and CNTs/LA ratio were evaluated and optimized in what concerns the LA recovered activity. Additionally, the back extraction of the enzyme from the material was evaluated with buffer solutions at several pH values. The results show a total adsorption of LA by the CNTs. Moreover, the ideal conditions for LA adsorption occur at pH between 7-8 during 1 h with LA recovery activities between 50 and 65%. Envisaging the development of a cost-effective and sustainable purification platform for LA, the back extraction of the enzyme from the material is ongoing.