Spectroscopic Study of the Interaction of Carboxyl-Modified Gold Nanoparticles with Liposomes of Different Chain Lengths and Controlled Drug Release by Layer-by-Layer Technology

Abstract

In this article, we investigate the interactions of carboxyl-modified gold nanoparticles (AuC) with zwitterionic phospholipid liposomes of different chain lengths using a well-known membrane probe PRODAN by steady-state and time-resolved spectroscopy. We use three zwitterionic lipids, namely, dipalmitoylphosphatidylcholine (DPPC), 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), and 1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC), which are widely different in their phase transition temperatures to form liposome-AuC assemblies. The steady-state and time-resolved studies indicate that the AuC brings in stability toward liposomes by local gelation. We observe that the bound AuC detach from the surface of the liposomes under pH ≈ 5 due to protonation of the carboxyl group, thus eliminating the electrostatic interaction between nanoparticles and head groups of liposomes. The detachment rate of AuC from the liposome-AuC assemblies is different for the aforementioned liposomes due to differences in their fluidity. We exploited the phenomena for the controlled release of a prominent anticancer drug Doxorubicin (DOX) under acidic conditions for different zwitterionic liposomes. The drug release rate was further optimized by coating of liposome-AuC assemblies with oppositely charged polymer (P), polydiallyldimethylammonium chloride, followed by a mixture of lipids L (DMPC:DMPG) and again with a polymer in a layer-by-layer fashion to obtain capsule-like structures. This system is highly stable for weeks, as confirmed by field-emission scanning electron microscopy (FE-SEM) and confocal laser scanning microscopy (CLSM) imaging, and inhibits premature release. The layer coating was confirmed by hydrodynamic size and zeta potential measurements of the systems. The capsules obtained are of immense importance as they can control release of the drug from the systems to a large extent.

Size dependency of gold nanoparticles interacting with model membranes

“…Among the many possible ENMs, spherical gold nanoparticles (AuNPs) have emerged as promising candidates for biomedical diagnostic, therapeutic and photoelectrochemical applications [14][15][16] due to their facile surface chemistry, ease of synthesis and tuneable size. Depending on the specific AuNPs, membrane and dispersant properties, various interaction outcomes have been observed 5,6,12,[17][18][19] . For example, cationic 20 or hydrophobically 12 functionalised AuNPs (<5 nm) can successfully be internalised within the membrane bilayer.…”

Tuning stable noble metal nanoparticles dispersions to moderate their interaction with model membranes

“…In spite of this, considerable uncertainty still relates to their possible mechanisms of interaction with biological tissues and organisms. Physicochemical model systems are particularly valuable in underpinning the detailed mechanisms of interaction that arise in highly complex living matter [14], with a considerable amount of work looking at the interaction of Au and Ag nanoparticles with biological membranes (biomembranes) [15,16] and biomembrane models [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31]. The reason for the latter approach is that the biomembrane is the first point of entry of a nanoparticle in media to an organism and in addition it is the most vulnerable entity open to attack from a xenobiotic species.…”

“…In general the interactions of Au nanoparticle dispersions on model biomembranes has been quite extensive over the last decade [18][19][20][21][22][23][24][25][26][27][28][29][30]. Many different Au particle dispersion types were used with variously reported results [18][19][20][21][22][23][24][25][26][27][28][29]. Au particles interacted to various degrees with model membranes.…”

Liposomes‐Camouflaged Redox‐Responsive Nanogels to Resolve the Dilemma between Extracellular Stability and Intracellular Drug Release

“…Especially, PEGylated stealth liposomes with the ability to avoid rapid clearance of the reticuloendothelial system can passively accumulate in tumors, i.e., Doxil, Caelyx, Myocet, DaunoXome, etc., demonstrating high therapeutic efficacy and low side effects . However, the clinical applications of liposomal formulations are largely restricted by their low storage stability, substantial premature drug leakage, especially slow and passive drug release following uptake into their target cells …”

“…[2,6,8] However, the clinical applications of liposomal formulations are largely restricted by their low storage stability, substantial premature drug leakage, especially slow and passive drug release following uptake into their target cells. [2,6,8,[10][11][12] Several approaches have been applied to enhance the performance of liposomes. Liposomes surface functionalization is the most commonly used method to adjust the properties of the liposomes.…”