Investigation of the biocompatibility and cytotoxicity associated with ROP initiator and its role in bulk polymerization of l-lactide

Green synthesis of methoxy-poly(ethylene glycol)-block-poly(l-lactide-co-glycolide) copolymer using zinc proline as a biocompatible initiator for irinotecan delivery to colon cancer in vivo

“…Synthesis and characterization of mPEG-PLGA copolymer mPEG-PLGA copolymer was synthesized using biocompatible, non-toxic zinc proline as an alternative initiator to avoid the huge cost and efforts associated with tin removal after stannous octoate catalyzed polymerization reactions (Scheme 1). In our previous work synthesizing PLA, 15 computational modelling suggested monomer lactide first coordinated with zinc proline and replaced one of the ligands to form a complex which acted as the initiator and such ligand exchange initiated the ROP. In the present mPEG-PLGA synthesis, since glycolide is more reactive than L-lactide, it is likely that one ligand of zinc proline was replaced with glycolide to form zinc proline glycolide complex which acted as the actual initiator.…”

“…Synthesis of mPEG-PLGA by ring-opening polymerization mPEG-PLGA copolymer was synthesized according to the method developed by Parwe et al employed for PLA synthesis with some modifications (Scheme 1). 15 Briefly, polymerization was carried out in sealed glass ampoules (inner diameter of 2 cm and 10 cm in height) in absence of solvents. Glass ampoules were passivated using 20% trimethylsilyl chloride (Me 3 SiCl) in acetone before polymerization.…”

“…13,14 We have previously synthesised PLAs using a green approach in the presence of the biocompatible zinc proline complex in bulk polymerization. 15 In the present study, we attempted to synthesize mPEG-PLGA from L-lactide, glycolide monomers and m-PEG-OH in the presence of zinc proline complex using solvent-free bulk ROP.…”

Polymer-supported metal catalysts for the heterogeneous polymerisation of lactones

“…At present, industrial production of PLA is achieved in molten monomer by catalytic ROP using homogeneous tin(II) 2-ethylhexanoate, Sn(Oct) 2 . 7 Although this catalyst has been approved by the US FDA, 8 its homogeneous nature means that complete removal of the catalyst from the final product is not feasible, resulting in incorporation of the catalyst into the final product. In addition to increasing the cost of the polymer and decreasing the atom efficiency of the process, the presence of the catalyst in the final polymer is also problematic due to the potential toxicity of tin, which has been reported to inhibit cell growth by 50% in low doses.…”

“…In addition to increasing the cost of the polymer and decreasing the atom efficiency of the process, the presence of the catalyst in the final polymer is also problematic due to the potential toxicity of tin, which has been reported to inhibit cell growth by 50% in low doses. [7][8][9] As such, difficulties arise in using PLA, and other polyesters made in similar way, in biomedical applications such as sutures, as the breakdown of the polymer could release residual metals into the body.…”