Couturier Brianna, Kozak Gloria, Levering John, Zini Anna, Elinski Meagan B
Department of Chemistry, Hope College, Holland, Michigan 49423, United States.
ACS Omega. 2024 Oct 14;9(42):42858-42867. doi: 10.1021/acsomega.4c05102. eCollection 2024 Oct 22.
The expansive use of hydrogels in healthcare relies on carefully tuned properties in dynamic environments with predictable behavior, including time sensitive biological systems and biomedical applications. To meet demands in these settings, nanomaterials are often introduced to a hydrogel matrix which simultaneously elevates potential applications while adding complexity to fundamental characteristics. With respect to drug delivery, gold nanoparticles have modifiable surfaces to carry an array of targeted drug treatments. However, different molecules acting as capping ligands possess different chemical structures that can impact gelation times. To understand the influence of capping ligand chemistry on polyacrylamide (PAM) based nanocomposite hydrogel radical gelation time, gold nanoparticle (Au NP) capping ligands were selected to encompass varying functional groups and molecular weights: citrate, cetyltrimethylammonium bromide, polyvinylpyrrolidone, and poly(acrylic acid). Gelation times were quantified as the storage-loss moduli crossover point in rheological time sweeps at constant strain and frequency. The dominating factor for gelation time was the presence of Au NPs, independent of a diverse range of capping ligand structures. The gelation times were also markedly faster than the same capping ligand structures used as stand-alone molecular additives. The accelerated Au NP gelation times, under 2 min, are attributed to the Au NPs acting as a cross-linker, promoting gelation. These results bolster the potential implementation of Au NP nanocomposite hydrogels in time-sensitive biomedical applications as robust drug carriers.
水凝胶在医疗保健领域的广泛应用依赖于其在动态环境中经过精心调节的特性，这些环境具有可预测的行为，包括对时间敏感的生物系统和生物医学应用。为了满足这些环境中的需求，纳米材料通常被引入水凝胶基质中，这在提升潜在应用的同时，也增加了基本特性的复杂性。在药物递送方面，金纳米颗粒具有可修饰的表面，能够携带一系列靶向药物治疗。然而，作为封端配体的不同分子具有不同的化学结构，这可能会影响凝胶化时间。为了理解封端配体化学对基于聚丙烯酰胺（PAM）的纳米复合水凝胶自由基凝胶化时间的影响，选择了金纳米颗粒（Au NP）封端配体，以涵盖不同的官能团和分子量：柠檬酸盐、十六烷基三甲基溴化铵、聚乙烯吡咯烷酮和聚丙烯酸。凝胶化时间被量化为在恒定应变和频率下进行流变时间扫描时储能模量与损耗模量的交叉点。凝胶化时间的主导因素是金纳米颗粒的存在，而与各种封端配体结构无关。凝胶化时间也明显快于用作单独分子添加剂的相同封端配体结构。在2分钟内加速的金纳米颗粒凝胶化时间归因于金纳米颗粒作为交联剂促进凝胶化。这些结果支持了金纳米颗粒纳米复合水凝胶在对时间敏感的生物医学应用中作为强大药物载体的潜在应用。
