TY - JOUR
T1 - On the structure of solid lipid nanoparticles
AU - Pink , Demi L.
AU - Loruthai , Orathai
AU - Ziolek, Robert M.
AU - Wasutrasawat, Prawarisa
AU - Terry , Ann E.
AU - Lawrence, Jayne
AU - Lorenz, Christian D.
PY - 2019/9/18
Y1 - 2019/9/18
N2 - Solid lipid nanoparticles (SLNs) have a crystalline lipid core which is stabilised by interfacial surfactants. SLNs are considered favorable candidates for drug delivery vehicles since their ability to store and release organic molecules can be tailored through the identity of the lipids and surfactants used. When stored, polymorphic transitions in the core of drug-loaded SLNs lead to the premature release of drug molecules. Significant experimental studies have been conducted with the aim of investigating the physico-chemical properties of SLNs, however, no molecular scale investigations have been reported on the behaviors that drive SLN formation and their polymorphic transitions. We have therefore used a combination of small angle neutron scattering (SANS) and all-atom molecular dynamics simulations (MS) to yield a detailed atomistic description of the internal structure of an SLN comprising of triglyceride, tripalmitin, and the nonionic surfactant, Brij O10 (C18:1E10). We uncover the molecular scale mechanisms by which the surfactants stabilise the crystalline structure of the SLN lipid core. By comparing these results to simulated liquid and solid aggregates of tripalmitin lipids, we demonstrate how the morphology of the lipids vary between these systems providing further insight into the mechanisms that control drug encapsulation and release from SLNs.
AB - Solid lipid nanoparticles (SLNs) have a crystalline lipid core which is stabilised by interfacial surfactants. SLNs are considered favorable candidates for drug delivery vehicles since their ability to store and release organic molecules can be tailored through the identity of the lipids and surfactants used. When stored, polymorphic transitions in the core of drug-loaded SLNs lead to the premature release of drug molecules. Significant experimental studies have been conducted with the aim of investigating the physico-chemical properties of SLNs, however, no molecular scale investigations have been reported on the behaviors that drive SLN formation and their polymorphic transitions. We have therefore used a combination of small angle neutron scattering (SANS) and all-atom molecular dynamics simulations (MS) to yield a detailed atomistic description of the internal structure of an SLN comprising of triglyceride, tripalmitin, and the nonionic surfactant, Brij O10 (C18:1E10). We uncover the molecular scale mechanisms by which the surfactants stabilise the crystalline structure of the SLN lipid core. By comparing these results to simulated liquid and solid aggregates of tripalmitin lipids, we demonstrate how the morphology of the lipids vary between these systems providing further insight into the mechanisms that control drug encapsulation and release from SLNs.
U2 - 10.1002/smll.201903156
DO - 10.1002/smll.201903156
M3 - Article
SN - 1613-6810
VL - 15
JO - Small
JF - Small
IS - 45
M1 - 1903156
ER -