Zirconium amine tris(phenolate): A more effective initiator for biomedical lactide

•Tin and zirconium initiators were used to produce polylactide (PLA).•MG63 cells were grown on PLA films made with the different initiators.•Differences in cell behavior were attributed to the different metal residues.•PLA produced using the zirconium initiator provided favorable scaffold properties.

Here a zirconium amine tris(phenolate) is used as the initiator for the production of polylactide for biomedical applications, as a replacement for a tin initiator (usually tin octanoate). The ring opening polymerization (ROP) was carried out in the melt at 130 °C. The zirconium-catalyzed PLA (PLA-Zr) required 30 min, resulting in a polydispersity index (PDI) of 1.17, compared to 1 h and PDI = 1.77 for tin-catalyzed PLA (PLA-Sn). PLA-Zr and PLA-Sn supported osteosarcoma cell (MG63) culture to the same extent (cell number, morphology, extracellular matrix production and osteogenic function) until day 14 when the PLA-Zr showed increased cell number, overall extracellular matrix production and osteogenic function. To conclude, the reduction in reaction time, controllable microstructure and biologically benign nature of the zirconium amine tris(phenolate) initiator shows that it is a more effective initiator for ROP of polylactide for biomedical applications.

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