Insertion of Nanoparticle Clusters into Vesicle Bilayers

Abstract

. z These authors contributed equally to this work.C ombining nanoparticles with liposomes is a highly elaborative methodology in the emerging fields of nanomedicine and nanobiotechnology. Not only can the well-known benefits 1 of liposomes be enhanced for specific applications, but their established scope of functionality (e.g., targeted drug delivery 2À7 ) can also be widely expanded to fulfill additional tasks and thereby act as eclectic toolboxes at a nanoscale. 8 Lipid bilayer membranes alone are significantly relevant materials for a broad range of academic disciplines. Their interactions with nanoparticles have been gradually studied over the past years, particularly in the context of nanoparticle transport across cellular membranes. 9À12 Notable experimental and theoretical studies have addressed different variables (e.g., the nanoparticle size or lipid composition) and their effects on adhesion and wrapping or nanoparticle-induced pore formation. 12À15 These concepts have been complemented by, for example, molecular dynamics simulations 16 or mesoscale thermodynamic modeling 13 and provide, among others, more accurate descriptions of phospholipid membranes to determine the role and effects of nanoparticles on lipid bilayers in general.In the context of stimuli-responsive liposomeÀnanoparticle hybrids for drug delivery, embedding hydrophobic nanoparticles directly within the liposomal lipid bilayer has become a popular approach. There are several standards in the literature on this subject, 17À21 which also present operative methodologies to accomplish this task. In this wide-ranging field, leading studies have focused on using very small nanoparticles * Address correspondence to alke.fink@unifr.ch. ABSTRACTA major contemporary concern in developing effective liposomeÀnanoparticle hybrids is the present inclusion size limitation of nanoparticles betw vesicle bilayers, which is considered to be around 6.5 nm in diameter. In this article, we present experimental observations backed by theore considerations which show that greater structures can be incorporated within vesicle membranes by promoting the clustering of nanoparticles be liposome formation. Cryo-transmission electron microscopy and cryo-electron tomography confirm these observations at unprecedented detail underpin that the liposome membranes can accommodate flexible structures of up to 60 nm in size. These results imply that this material is more vers in terms of inclusion capabilities and consequently widens the opportunities in developing multivalent vesicles for nanobiotechnology applications

Interaction of polymer-coated silicon nanocrystals with lipid bilayers and surfactant interfaces

“…This suggests that the uptake of nanoparticles with pure PEGylated-phospholipid coronas depends critically on the presence of other components, such as proteins [75]. When attraction does occur, it could be explained by 'defects' or 'patches' of below-average PEG coverage that have reduced hydrophilicity and hence a natural affinity for the interface [76]. Although uncommon in this study, the occurrence of attractive behavior is noteworthy because it suggests potential strategies for controlling cellular uptake by engineering 'patchiness' through precise control over heterogeneities in the PEG coating.…”

Catechol-derivatized poly(vinyl alcohol) as a coating molecule for magnetic nanoclusters

“…for MRI or magnetic fluid hyperthermia). As a contemporary example, they are promising components of recently developed magnetic liposomes [13], which rely on well-defined and densely loaded clusters composed of individual superparamagnetic nanoparticles.…”

“…Superparamagnetic iron oxide nanoparticles (SPIONs) are forerunners in this development [2] due to their fascinating physico-chemical [3,4] (i.e. superparamagnetic) properties, which make them exceptional candidates for a broad variety of clinical applications, ranging from basic contrast agents [5][6][7][8] or thermoregulators [9] to sophisticated drug delivery vectors [10][11][12][13]. Nonetheless, the therapeutic window with respect to the efficiency of these materials, in other words the size range in which these properties can be exploited, is relatively small: nanoparticles larger than approximately 20 nm [14] lose their superparamagnetic properties, whereas ultrasmall single nanoparticles (i.e.…”

Magnetoliposomes: opportunities and challenges

“…For NPs embedded in the lipid bilayer, SPIONs coated with oleic acid (41)(42)(43) are the favored choice. Another alternative was presented by Amstad and colleagues (44) by introducing SPIONs stabilized with palmityl-nitroDOPA ( Figure 2C, IV) into the lipid membrane, arguing that such particles were less prone to aggregation than standard oleic acidcoated SPIONs and that they embed themselves more willingly in between the bilayer.…”