Cytoskeleton-inspired, adaptive nanolipogels as superlubricating delivery vehicles
细胞骨架启发的自适应纳米脂质凝胶作为超润滑递送载体
Panpan Zhao*, Avijit Mondal, Nir Kampf, Aleksei Solomonov, Roman Kamyshinsky, Jacob Klein*
AI总结 受细胞骨架启发,通过氢键和阳离子-π相互作用构建的纳米脂质凝胶(NLGs)在保持超低摩擦(摩擦系数低至10⁻⁴)的同时,实现药物递送和界面摩擦耗散的大幅降低,并能在高压下恢复润滑性能。
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磷脂酰胆碱脂质体通过关节内给药在缓解骨关节炎方面具有独特优势,这归因于其在关节软骨表面的超润滑性,但作为药物递送囊泡在治疗中的共同应用仍具挑战,因为它们在机械应力下可能破裂。在这里,我们描述了受细胞骨架启发的超分子自组装纳米脂质凝胶(NLGs),其包含由氢键和阳离子-π相互作用形成的动态网络的脂质体包裹的纳米凝胶,作为同时实现稳健药物递送和大幅降低界面摩擦耗散的平台。我们使用表面力天平在亚纳米级别评估这种耗散,阐明所涉及的机制,并使用原子力显微镜探测NLGs的结构稳定性。界面耗散的一个有用指标是摩擦系数,在接触压力至少高达2 MPa时,它保持在低至10⁻⁴的水平,而在超过氢键能量密度的更高压力下,它突然且不可逆地增加到仍然较低的10⁻²值。然而,在此阈值以上持续滑动时,摩擦逐渐再次降低,表明润滑界面的恢复。分子动力学模拟确定了由于纳米凝胶内氢键断裂/重排引起的压应力降低,这是与润滑失效和恢复相关的埋藏超分子转变,而滑动过程中的货物释放强调了此类NLGs的药物递送潜力。这些发现揭示了超分子核壳增强如何调节承载水合润滑,并为设计同时作为承载关节内货物递送载体的自适应仿生润滑剂提供了框架。
Phosphatidylcholine liposomes fill a special niche in alleviating osteoarthritis via intra-articular (IA) administration, attributed to their superlubricity at the articular cartilage surface, but their co-utilization as drug delivery vesicles in such therapy remains challenging as they may rupture under mechanical stress. Here, we describe cytoskeleton-inspired, supramolecular, self-assembled nanolipogels (NLGs), encompassing liposome-encased nanogels with a dynamic network formed by hydrogen bonding and cation-pi interactions, as a platform for simultaneous robust drug-delivery and massive reduction of interfacial frictional dissipation. We use a surface force balance to assess such dissipation at the sub-nanometer level, elucidating the mechanism involved, and atomic force microscopy to probe the NLGs structural stability. A useful proxy for the interfacial dissipation is the coefficient of friction, which remains as low as 10-4 at contact pressures at least up to 2 MPa, while under higher pressures exceeding the H-bonding energy density it increases abruptly and irreversibly to the still-low value 10-2. Under sustained sliding above this threshold, however, friction gradually decreases again, indicating recovery of the lubricating interface. Molecular dynamics simulations identify the compressive stress decrease due to hydrogen-bond rupture/rearrangement within the nanogel as a buried supramolecular transition associated with lubrication breakdown and recovery, while cargo release during sliding emphasizes the drug-delivery potential of such NLGs. These findings reveal how supramolecular core-shell reinforcement regulates load-bearing hydration lubrication, and provides a framework for designing adaptive biomimetic lubricants which are at the same time load-bearing intra-articular cargo-delivery vehicles.