School of Chemical Sciences, Dublin City University, Dublin 9, Ireland.
Biomacromolecules. 2013 Jan 14;14(1):200-6. doi: 10.1021/bm301629f. Epub 2012 Dec 7.
Novel block copolymers comprising poly(ethylene glycol) (PEG) and an oligo(tyrosine) block were synthesized in different compositions by N-carboxyanhydride (NCA) polymerization. It was shown that PEG2000-Tyr(6) undergoes thermoresponsive hydrogelation at a low concentration range of 0.25-3.0 wt % within a temperature range of 25-50 °C. Cryogenic transmission electron microscopy (Cryo-TEM) revealed a continuous network of fibers throughout the hydrogel sample, even at concentrations as low as 0.25 wt %. Circular dichroism (CD) results suggest that better packing of the β-sheet tyrosine block at increasing temperature induces the reverse thermogelation. A preliminary assessment of the potential of the hydrogel for in vitro application confirmed the hydrogel is not cytotoxic, is biodegradable, and produced a sustained release of a small-molecule drug.
新型嵌段共聚物由聚乙二醇（PEG）和寡聚（酪氨酸）嵌段组成，通过 N-羧酸酐（NCA）聚合以不同的组成合成。结果表明，PEG2000-Tyr（6）在 25-50°C 的温度范围内以 0.25-3.0wt%的低浓度范围经历热响应水凝胶化。低温透射电子显微镜（Cryo-TEM）显示，即使在低至 0.25wt%的浓度下，整个水凝胶样品中也存在纤维的连续网络。圆二色性（CD）结果表明，β-折叠酪氨酸嵌段在升温过程中更好的堆积诱导了反向热凝胶化。对水凝胶在体外应用的潜在性的初步评估证实，水凝胶无细胞毒性，可生物降解，并能持续释放小分子药物。
