title: Bioprocessing of bacteriophages via rapid drying onto microcrystals.
abstract: We present an alternative bioprocess for bacteriophages involving room temperature coprecipitation of an aqueous mixture of phage (Siphoviridae) and a crystallizable carrier (glutamine or glycine) in excess of water miscible organic solvent (isopropanol or isobutanol). The resultant suspension of phage-coated microcrystals can be harvested by filtration and the residual solvent removed rapidly by air-drying at a relative humidity of 75%. Albumin or trehalose added at 5% w/w of the crystalline carrier provide for better stabilization of the phage during co-precipitation. Free-flowing dry powders generated from an aqueous solution of phage (∼13 log(10) pfu/mL) can be reconstituted in the same aqueous volume to a phage titer of almost 10 log(10) pfu/mL; high enough to permit subsequent formulation steps following bioprocessing. The phage-coated microcrystals remain partially stable at room temperature for at least one month, which compares favorably with phage immobilized into polyester microcarriers or lyophilized with excipient (1-5% polyethylene glycol 6000 or 0.1-0.5 M sucrose). We anticipate that this bioprocessing technique will have application to other phage families as required for the development of phage therapies.
authors: Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow G4 0RE, UK.
authors: Eva
authors: E
authors: Alvarez-Gonzalez
authors: Munerah
authors: M
authors: Alfadhel
authors: Parag
authors: P
authors: Mane
authors: Steven J
authors: SJ
authors: Ford
authors: Barry D
authors: BD
authors: Moore
authors: Christopher F
authors: CF
authors: van der Walle
mesh_terms: D003451:Cryoprotective Agents / Q000494:pharmacology; D005612:Freeze Drying / Q000379:methods*; D013204:Staphylococcus Phages / Q000737:chemistry* / Q000187:drug effects / Q000502:physiology; D013499:Surface Properties; D013696:Temperature
chemical_list: D003451:Cryoprotective Agents