Department of Basic Pharmaceutical Sciences, College of Pharmacy, University of Louisiana at Monroe, 1800 Bienville Drive, Monroe, LA 71201, USA.
Colloids Surf B Biointerfaces. 2010 Jun 1;77(2):286-97. doi: 10.1016/j.colsurfb.2010.02.003. Epub 2010 Feb 11.
Nanostructured lipid carriers (NLCs), made from mixtures of solid and liquid lipids, were postulated to have superior properties over solid lipid nanoparticles (SLNs). Nonetheless, the architecture of their inner cores remains elusive. The objective of this study was to elucidate the mode by which tocotrienol-rich fraction (TRF) is entrapped within NLCs and the impact of TRF interaction with solid lipids on the long-term stability of the nanoparticles. The mode of TRF localization was postulated from TEM image analysis and (1)H NMR signals' amplitude. The size, polydispersity, and fusion enthalpy were found to decrease with an increase in TRF loading, which implied a distortion in the crystallinity of the nanoparticles and the preferential entrapment of TRF within the cores of the NLCs. Nonetheless, (1)H NMR spectra of TRF-NLCs broadened as TRF load decreased from 100 to 10%, which was attributed to partial TRF mobility on the surface of the nanoparticles. This was confirmed by TEM images of NLCs at 50% TRF loads. These data led to the conclusion that NLCs have limited capacity to accommodate TRF with the excess being expelled to the surface of the nanoparticles. Such arrangement may have implication on future utility of the NLCs as drug delivery vehicles.
纳米结构脂质载体（NLCs）由固体和液体脂质的混合物制成，被认为具有优于固体脂质纳米粒（SLNs）的特性。然而，其内核的结构仍然难以捉摸。本研究的目的是阐明生育三烯酚（TRF）被包封在 NLC 中的方式，以及 TRF 与固体脂质相互作用对纳米粒子长期稳定性的影响。通过 TEM 图像分析和（1）H NMR 信号幅度来推测 TRF 定位模式。发现随着 TRF 负载的增加，粒径、多分散性和融合焓减小，这意味着纳米粒子的结晶度发生了扭曲，并且 TRF 优先被包封在 NLC 的核内。然而，随着 TRF 负载从 100%降至 10%，TRF-NLCs 的（1）H NMR 光谱变宽，这归因于部分 TRF 在纳米粒子表面的部分迁移。这通过 50% TRF 负载的 NLCs 的 TEM 图像得到证实。这些数据得出的结论是，NLC 对 TRF 的容纳能力有限，多余的 TRF 被排斥到纳米粒子的表面。这种排列可能对 NLC 作为药物输送载体的未来应用具有影响。
