Department of Biomedical Engineering, School of Engineering, Virginia Commonwealth University, Richmond, Virginia 23284, USA.
Biomacromolecules. 2010 Mar 8;11(3):666-73. doi: 10.1021/bm901240g.
In this work, we describe a novel polyamidoamine (PAMAM) dendrimer hydrogel (DH) platform with potential for tissue engineering and drug delivery. With PAMAM dendrimer G3.0 being the underlying carrier, polyethylene glycol (PEG) chains of various lengths (MW = 1500, 6000, or 12000 g mol(-1)) were coupled to the dendrimer to different extents, and the resulting PEGylated PAMAM dendrimers were further coupled with acrylate groups to yield photoreactive dendrimer macromonomers for gel formation. It was found that gelation based on photoreactive PAMAM G3.0 macromonomers was restricted by the degree of PEGylation, PEG chain length, and the distribution of acrylate groups on the dendrimer surface. Further, the architecture of the photoreactive macromonomers affects the structural stability and swelling of the resultant networks. A completely cross-linked network (DH-G3.0-12000(H)) with a high water swelling ratio was created by UV-curing of PAMAM dendrimer G3.0 coupled with 28 PEG 12000 chains in the presence of the eosin Y-based photoinitiating system. The disintegration of DH-G3.0-12000(H) was pH-insensitive. DH-G3.0-12000(H) was found to have similar cytocompatibility to un-cross-linked G3.0-12000(H) but a significantly lower cellular uptake by macrophages. With PAMAM dendrimer G3.5 being the underlying carrier, the dendrimer modified with 43 PEG 1500 chains was able to form a completely cross-linked network (DH-G3.5-1500(H)) by UV-curing in the presence of the eosin Y-based photoinitiating system. DH-G3.5-1500(H) exhibited pH-dependent disintegration. Its disintegration ratio increased with pH. PAMAM dendrimer hydrogels uniquely express the structural characteristics of both PEG hydrogel and PAMAM dendrimer and have potential for various applications in tissue engineering and drug delivery.
在这项工作中，我们描述了一种具有组织工程和药物输送潜力的新型聚酰胺胺（PAMAM）树枝状聚合物水凝胶（DH）平台。以 PAMAM 树枝状聚合物 G3.0 为基础载体，将不同长度（MW=1500、6000 或 12000g/mol）的聚乙二醇（PEG）链与树枝状聚合物进行不同程度的偶联，得到的 PEG 化 PAMAM 树枝状聚合物进一步与丙烯酰胺基团偶联，得到用于凝胶形成的光反应性树枝状大分子单体。结果发现，基于光反应性 PAMAM G3.0 大分子单体的凝胶化受到 PEG 化程度、PEG 链长和树枝状聚合物表面丙烯酰胺基团分布的限制。此外，光反应性大分子单体的结构影响所得网络的结构稳定性和溶胀性。通过在基于曙红 Y 的光引发体系存在下用紫外光固化 PAMAM 树枝状聚合物 G3.0 与 28 个 PEG12000 链，制备了具有高溶胀比的完全交联网络（DH-G3.0-12000(H)）。DH-G3.0-12000(H)的崩解对 pH 不敏感。发现 DH-G3.0-12000(H)与未交联的 G3.0-12000(H)具有相似的细胞相容性，但巨噬细胞摄取率显著降低。以 PAMAM 树枝状聚合物 G3.5 为基础载体，用 43 个 PEG1500 链修饰的树枝状聚合物能够在基于曙红 Y 的光引发体系存在下用紫外光固化形成完全交联网络（DH-G3.5-1500(H)）。DH-G3.5-1500(H)表现出 pH 依赖性崩解。其崩解率随 pH 增加而增加。PAMAM 树枝状聚合物水凝胶独特地表达了 PEG 水凝胶和 PAMAM 树枝状聚合物的结构特征，在组织工程和药物输送等领域具有广泛的应用潜力。
