One way to form tough hydrogels is to create structures with homogeneous networks, such as Tetra-PEG hydrogels. In the current work, Poly(amidoamine) (PAMAM) dendrimers were introduced into Tetra-PEG hydrogels via Schiff base reaction between NH₂ groups on PAMAM and CHO groups on 4arm-PEG-aldehyde. The results indicated that the mechanical properties of PAMAM-Tetra-PEG hydrogels were very dependent on the generation of PAMAM. When PAMAM-G1 was introduced, nearly all of the formed hydrogels tended to be mucilage-like semisolids, while PAMAM-G3 or PAMAM-G5 was introduced, no matter what molecular weight or ratio of 4arm-PEG was paired with, the formed hydrogels tended to be solid elastomers, showing high compression strength (0.8722 MPa), and excellent fatigue resistance (~300 cycles of loading-unloading under strain of 90%). The swelling properties of the PAMAM-Tetra-PEG hydrogels were mainly affected by the 4arm-PEG molecular weight, PAMAM generation, and component ratio between PAMAM and 4arm-PEG, reaching to the highest swelling capacity of 1008%. SEM and SAXS confirmed that the formed PAMAM-Tetra-PEG hydrogels were comprised of very uniform networks. Additionally, because of well-defined hydrophobic empty cavities in high-generation PAMAM, the PAMAM-G5-Tetra-PEG hydrogels showed dual-embedding capacity for both hydrophilic and hydrophobic substances, and had potential as dual-function delivery systems.

形成坚韧水凝胶的一种方法是创建具有均质网络的结构，例如 Tetra-PEG 水凝胶。在目前的工作中，聚（酰胺胺）（PAMAM）树枝状聚合物通过 NH ₂PAMAM 上的基团和 4arm-PEG-醛上的 CHO 基团。结果表明，PAMAM-Tetra-PEG 水凝胶的力学性能非常依赖于 PAMAM 的生成。当引入 PAMAM-G1 时，几乎所有形成的水凝胶都趋向于粘液状半固体，而引入 PAMAM-G3 或 PAMAM-G5 时，无论 4arm-PEG 与什么分子量或比例配对，形成的水凝胶往往是固体弹性体，具有高压缩强度 (0.8722 MPa) 和出色的抗疲劳性（在 90% 应变下约 300 次加载-卸载循环）。PAMAM-Tetra-PEG 水凝胶的溶胀性能主要受 4arm-PEG 分子量、PAMAM 生成以及 PAMAM 与 4arm-PEG 组分比的影响，最高溶胀能力达到 1008%。SEM 和 SAXS 证实形成的 PAMAM-Tetra-PEG 水凝胶由非常均匀的网络组成。此外，由于高代 PAMAM 中定义明确的疏水空腔，PAMAM-G5-Tetra-PEG 水凝胶对亲水和疏水物质显示出双重嵌入能力，并具有作为双功能递送系统的潜力。