title: Pharmaceutical-grade pre-miR-29 purification using an agmatine monolithic support.
abstract: MicroRNA-based therapeutic applications have fostered a growing interest in the development of microRNAs purification processes in order to obtain the final product with high purity degree, good quality and biologically active. The pre-miR-29 deficiency or overexpression has been associated to a number of clinically important diseases, and its therapeutic application can be considered. Monolithic columns emerged as a new class of chromatographic supports used in the plasmid DNA purification platforms, being an interesting alternative to the conventional particle-based columns. Thus, the current work describes, for the first time, a new affinity chromatography method that combines the high selectivity of agmatine ligands with the versatility of monoliths to specifically and efficiently purify pre-miR-29 from other small RNA species and Rhodovulum sulfidophilum impurities. The effect of different flow rates on pre-miR-29 separation was also evaluated. Moreover, breakthrough experiments were designed to study the effect of different RNA concentrations on the modified monolithic support binding capacity, being verified that the dynamic binding capacity for RNA molecules is dependent of the feed concentration. In order to achieve higher efficiency and selectivity, three different binding and elution strategies based on increased sodium chloride (1.75-3M) or arginine (100mM) and decreased ammonium sulfate (2.4-0M) stepwise gradients are described to purify pre-miR-29. As a matter of fact, by employing elution strategies using sodium chloride or arginine, an improvement in the final pre-miR-29 yields (97.33 and 94.88%, respectively) as well as purity (75.21 and 90.11%, respectively) were obtained. Moreover, the quality control analysis revealed that the level of impurities (proteins, endotoxins, sRNA) in the final pre-miR-29 sample was negligible. In fact, this new monolithic support arises as a powerful instrument on the microRNA purification to be used in further clinical applications, providing a more rapid and economical purification platform.
authors.affiliation: CICS - Health Sciences Research Centre, University of Beira Interior, Avenida Infante D. Henrique, 6200-506 Covilhã, Portugal.
authors.forename: Patrícia
authors.initials: P
authors.lastname: Pereira
authors.affiliation: CICS - Health Sciences Research Centre, University of Beira Interior, Avenida Infante D. Henrique, 6200-506 Covilhã, Portugal.
authors.forename: Ângela
authors.initials: Â
authors.lastname: Sousa
authors.affiliation: CICS - Health Sciences Research Centre, University of Beira Interior, Avenida Infante D. Henrique, 6200-506 Covilhã, Portugal.
authors.forename: João A
authors.initials: JA
authors.lastname: Queiroz
authors.affiliation: CICS - Health Sciences Research Centre, University of Beira Interior, Avenida Infante D. Henrique, 6200-506 Covilhã, Portugal; CNC - Center of Neuroscience and Cell Biology, University of Coimbra, Largo Marquês de Pombal, 3004-517 Coimbra, Portugal.
authors.forename: Ana
authors.initials: A
authors.lastname: Figueiras
authors.affiliation: CICS - Health Sciences Research Centre, University of Beira Interior, Avenida Infante D. Henrique, 6200-506 Covilhã, Portugal. Electronic address: fani.sousa@fcsaude.ubi.pt.
authors.forename: Fani
authors.initials: F
authors.lastname: Sousa
mesh_terms: D000376:Agmatine / Q000737:chemistry*; D000645:Ammonium Sulfate; D001120:Arginine / Q000737:chemistry; D002846:Chromatography, Affinity / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D035683:MicroRNAs / Q000302:isolation & purification*; D010957:Plasmids; D012965:Sodium Chloride
chemical_list: D035683:MicroRNAs; D012965:Sodium Chloride; D000376:Agmatine; D001120:Arginine; D000645:Ammonium Sulfate
keywords: Affinity chromatography; Agmatine monolith; MicroRNA purification; Small RNA; pre-miR-29