高电荷双嵌段共多肽水凝胶中异常的盐稳定性。

Unusual salt stability in highly charged diblock co-polypeptide hydrogels.

作者信息

Nowak Andrew P, Breedveld Victor, Pine David J, Deming Timothy J

机构信息

Departments of Materials and Chemistry, Materials Research Laboratory, University of California, Santa Barbara, CA 93106, USA.

出版信息

J Am Chem Soc. 2003 Dec 17;125(50):15666-70. doi: 10.1021/ja0381050.

DOI:10.1021/ja0381050

PMID:14664616

Abstract

The stability and properties of dilute solution hydrogels, synthesized by transition metal mediated polymerization of amino acid N-carboxyanhydrides (NCAs), have been studied in deionized (DI) water as well as various ionic media. These hydrogels are diblock amphiphilic copolymers of hydrophilic, charged segments of poly(l-lysine HBr) or poly(l-glutamic acid sodium salt), and helical, hydrophobic segments of poly(l-leucine). While many of these samples are able to form strong gels in deionized water at polymer concentrations as low as 0.25 wt %, stability in salt or buffer solutions was found to be only achieved at moderately higher polymer concentrations ( approximately 3.0 wt %). We have adjusted relative copolymer compositions and molecular weights to optimize hydrogel strength and polymer solubility in salt concentrations up to 0.5 M NaCl, as well as in cell growth media and aqueous buffers of varying pH. These materials are unique since they do not collapse in high ionic strength media, even though gel formation is contingent upon the presence of highly charged polyelectrolyte segments. The remarkable properties of these hydrogels make them excellent candidates for use as scaffolds in biomedical applications, such as tissue regeneration.

摘要

通过过渡金属介导的氨基酸N - 羧基酐（NCA）聚合反应合成的稀溶液水凝胶，其稳定性和性质已在去离子水以及各种离子介质中进行了研究。这些水凝胶是由聚（L - 赖氨酸HBr）或聚（L - 谷氨酸钠盐）的亲水性带电链段与聚（L - 亮氨酸）的螺旋形疏水链段组成的二嵌段两亲共聚物。虽然许多这些样品在聚合物浓度低至0.25 wt％时就能在去离子水中形成强凝胶，但发现只有在适度较高的聚合物浓度（约3.0 wt％）下才能在盐溶液或缓冲溶液中保持稳定。我们已经调整了相对共聚物组成和分子量，以优化水凝胶强度以及聚合物在高达0.5 M NaCl的盐浓度、细胞生长培养基和不同pH值的水性缓冲液中的溶解度。这些材料很独特，因为即使凝胶形成取决于高电荷聚电解质链段的存在，它们在高离子强度介质中也不会塌陷。这些水凝胶的卓越性能使其成为生物医学应用（如组织再生）中用作支架的极佳候选材料。