Macromolecular prodrugs of ribavirin: towards a treatment for co-infection with HIV and HCV† †Electronic supplementary information (ESI) available: Additional experimental details and figures. See DOI: 10.1039/c4sc02754j Click here for additional data file. ‡A.A.A.S.; K.Z.; M.B.L.K.; B.W. contributed equally to this work.

Polymer synthesis. A Chemspeed Swing-SLT automated synthesizer was used for the parallel synthesis.16 The reactions were performed in a glass reactor block of 16 reactors (13 mL) with thermal jackets. These were connected in series to a Hüber thermoregulation system (−90 °C to 140 °C). The reactors were equipped with cold-finger reflux condensers and mixing was done by vortex agitation. The liquid transfers were performed by a 4-needle head, which was washed in between each transfer with dimethyl sulfoxide (DMSO). The DMSO reservoir was degassed by continuous nitrogen sparging. The needle head and tubing lines were also primed with DMSO prior to the transfers. The reaction vessels were heated to 135 °C and subjected to 10 cycles of vacuum and subsequent nitrogen filling prior to the experiments as to remove oxygen. The reaction mixtures were degassed through an automated parallel freeze-evacuatethaw degassing method. All stock solutions were degassed by sparging with nitrogen for 15 min before being put in the Chemspeed. The desired aliquots of stock solutions and solvent from the reservoir were transferred to the reactors with the automated liquid handling system. Penultimately, the reactors were degassed through three automated freeze-evacuate-thaw cycles, before the reactors were heated to 70 oC while subjected to vortex agitation for the duration of the polymerization.