Biodegradable and Biocompatible P DL LA-PEG 1k -P DL LA Diacrylate Macromers: Synthesis, Characterisation and Preparation of Soluble Hyperbranched Polymers and Crosslinked Hydrogels

摘要

A series of P DL LA-PEG 1k -P DL LA tri-block co-polymers with various compositions, i.e., containing 2–10 lactoyl units, were prepared via ring opening polymerisation of d , l -lactide in the presence of poly (ethylene glycol) (PEG) ( M n = 1000 g·mol ?1 ) as the initiator and stannous 2-ethylhexanoate as the catalyst at different feed ratios. P DL LA-PEG 1k -P DL LA co-polymers were then functionalised with acrylate groups using acryloyl chloride under various reaction conditions. The diacrylated P DL LA-PEG 1k -P DL LA (diacryl-P DL LA-PEG 1k -P DL LA) were further polymerised to synthesize soluble hyperbranched polymers by either homo-polymerisation or co-polymerisation with poly(ethylene glycol) methyl ether methylacrylate (PEGMEMA) via free radical polymerisation. The polymer samples obtained were characterised by 1 H NMR (proton Nuclear Magnetic Resonance), FTIR (Fourier Transform Infra-red spectroscopy), and GPC (Gel Permeation Chromatography). Moreover, the diacryl-P DL LA-PEG 1k -P DL LA macromers were used for the preparation of biodegradable crosslinked hydrogels through the Michael addition reaction and radical photo-polymerisation with or without poly(ethylene glycol) methyl ether methylacrylate (PEGMEMA, M n = 475 g·mol ?1 ) as the co-monomer. It was found that fine tuning of the diacryl-P DL LA-PEG 1k -P DL LA constituents and its combination with co-monomers resulted in hydrogels with tailored swelling properties. It is envisioned that soluble hyperbranched polymers and crosslinked hydrogels prepared from diacryl-P DL LA-PEG 1k -P DL LA macromers can have promising applications in the fields of nano-medicines and regenerative medicines.