3B's Research Group - Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark, 4806-909 Taipas, Guimarães, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal.
Acta Biomater. 2013 Nov;9(11):9086-97. doi: 10.1016/j.actbio.2013.06.036. Epub 2013 Jun 29.
Ulvan, extracted from the green algae Ulva lactuca, and chitosan, extracted from Loligo forbesis squid-pen, were carboxymethylated, yielding polysaccharides with an average degree of substitution of ∼98% (carboxymethyl ulvan, CMU) and ∼87% (carboxymethyl chitosan, N,O-CMC). The carboxymethylation was confirmed by Fourier transform infrared spectroscopy and quantified by conductimetric titration and 1H nuclear magnetic resonance. The average molecular weight increased with the carboxymethylation (chitosan, Mn 145→296 kDa and Mw 227→416 kDa; ulvan, Mn 139→261 kDa and Mw 368→640 kDa), indicating successful chemical modifications. Mixtures of the modified polysaccharides were tested in the formulation of polyacrylic acid-free glass-ionomer bone cements. Mechanical and in vitro bioactivity tests indicate that the inclusion of CMU in the cement formulation, i.e. 0.50:0.50 N,O-CMC:CMU, enhances its mechanical performance (compressive strength 52.4±8.0 MPa and modulus 2.3±0.3 GPa), generates non-cytotoxic cements and induces the diffusion of Ca and/or P-based moieties from the surface to the bulk of the cements.
从绿藻石莼中提取的岩藻聚糖和从枪乌贼笔尖提取的壳聚糖被羧甲基化，得到取代度约为 98%（羧甲基岩藻聚糖，CMU）和 87%（羧甲基壳聚糖，N,O-CMC）的多糖。羧甲基化通过傅里叶变换红外光谱得到证实，并通过电导率滴定和 1H 核磁共振定量。随着羧甲基化，平均分子量增加（壳聚糖，Mn 从 145 增加到 296 kDa，Mw 从 227 增加到 416 kDa；岩藻聚糖，Mn 从 139 增加到 261 kDa，Mw 从 368 增加到 640 kDa），表明化学修饰成功。改性多糖的混合物被测试用于制备不含聚丙烯酸的玻璃离子骨水泥。力学和体外生物活性测试表明，在水泥配方中加入 CMU，即 0.50:0.50 N,O-CMC:CMU，可提高其力学性能（抗压强度 52.4±8.0 MPa 和模量 2.3±0.3 GPa），生成非细胞毒性水泥，并促使 Ca 和/或 P 基部分从表面扩散到水泥的本体。
