Flowers Marcus, Paulsen Alex, Kaiser Claire R W, Tuma Adam B, Lim Hubert H, Ogle Brenda M, Wang Chun
Department of Biomedical Engineering, University of Minnesota, 7-105 Hasselmo Hall, 312 Church Street SE, Minneapolis, MN 55455, USA.
Department of Otolaryngology-Head and Neck Surgery, University of Minnesota, Phillips Wangensteen Building, 516 Delaware Street SE, Suite 8-240, Minneapolis, MN 55455, USA.
Pharmaceutics. 2025 Jan 19;17(1):133. doi: 10.3390/pharmaceutics17010133.
Focused ultrasound has advantages as an external stimulus for drug delivery as it is non-invasive, has high precision and can penetrate deep into tissues. Here, we report a gold-plated alginate (ALG) hydrogel system that retains highly water-soluble small-molecule fluorescein for sharp off/on release after ultrasound exposure. The ALG is crosslinked into beads with calcium chloride and layered with a polycation to adjust the surface charge for the adsorption of catalytic platinum nanoparticles (Pt NPs). The coated bead is subject to electroless plating, forming a gold shell. Ultrasound is applied to the gold-plated ALG beads and the release of fluorescein with or without ultrasound stimulation is quantified. Polyethylenimine (PEI), not poly-L-lysine (PLL), is able to facilitate Pt NP adsorption. Gold shell thickness is proportional to the duration of electroless plating and can be controlled. Gold-plated ALG beads are impermeable to the fluorescein cargo and have nearly zero leakage. Exposure to focused ultrasound initiated the release of fluorescein with full release achieved after 72 h. The gold-plated ALG hydrogel is a new material platform that can retain highly water-soluble molecules with a sharp off/on release initiated by focused ultrasound.
聚焦超声作为一种用于药物递送的外部刺激具有诸多优势，因为它是非侵入性的，具有高精度且能深入组织内部。在此，我们报道了一种镀金海藻酸盐（ALG）水凝胶系统，该系统能保留高度水溶性的小分子荧光素，在超声照射后实现荧光素的精确开关式释放。海藻酸盐通过氯化钙交联成珠，并与一种聚阳离子分层，以调节表面电荷用于催化铂纳米颗粒（Pt NPs）的吸附。对包被后的珠子进行化学镀，形成金壳。对镀金的海藻酸盐珠子施加超声，并对有无超声刺激时荧光素的释放进行定量。聚乙烯亚胺（PEI）而非聚-L-赖氨酸（PLL）能够促进铂纳米颗粒的吸附。金壳厚度与化学镀持续时间成正比且可控制。镀金的海藻酸盐珠子对荧光素货物具有不透性且几乎无泄漏。暴露于聚焦超声会引发荧光素的释放，72小时后实现完全释放。镀金的海藻酸盐水凝胶是一种新型材料平台，能够保留高度水溶性分子，并通过聚焦超声引发精确的开关式释放。
