Visualizing the Structure of Triglyceride Nanoparticles in Different Crystal Modifications

Bunjes, Heike; Steiniger, Frank; Richter, Walter

doi:10.1021/la062904p

Cited by 175 publications

(140 citation statements)

References 22 publications

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“…The intensity and position of the diffractions are unique to each type of crystalline material. XRD pattern can predict the manner of arrangement of lipid molecules, phase behavior, and characterize and identify the structure of lipid and drug molecules (75,76). However, best results are observed when SLN dispersions are investigated directly as solvent removal may change the modification.…”

Section: Crystallinity and Polymorphismmentioning

confidence: 99%

Recent Advances in Lipid Nanoparticle Formulations with Solid Matrix for Oral Drug Delivery

2010

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Abstract. Lipid nanoparticles based on solid matrix have emerged as potential drug carriers to improve gastrointestinal (GI) absorption and oral bioavailability of several drugs, especially lipophilic compounds. These formulations may also be used for sustained drug release. Solid lipid nanoparticle (SLN) and the newer generation lipid nanoparticle, nanostructured lipid carrier (NLC), have been studied for their capability as oral drug carriers. Biodegradable, biocompatible, and physiological lipids are generally used to prepare these nanoparticles. Hence, toxicity problems related with the polymeric nanoparticles can be minimized. Furthermore, stability of the formulations might increase than other liquid nano-carriers due to the solid matrix of these lipid nanoparticles. These nanoparticles can be produced by different formulation techniques. Scaling up of the production process from lab scale to industrial scale can be easily achieved. Reasonably high drug encapsulation efficiency of the nanoparticles was documented. Oral absorption and bioavailability of several drugs were improved after oral administration of the drugloaded SLNs or NLCs. In this review, pros and cons, different formulation and characterization techniques, drug incorporation models, GI absorption and oral bioavailability enhancement mechanisms, stability and storage condition of the formulations, and recent advances in oral delivery of the lipid nanoparticles based on solid matrix will be discussed.

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Section: Crystallinity and Polymorphismmentioning

confidence: 99%

Recent Advances in Lipid Nanoparticle Formulations with Solid Matrix for Oral Drug Delivery

2010

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“…The β-form is the most stable; therefore, the transition of liquid (melt) from a to β via β' is the pathway followed by triglycerides to achieve an optimum molecular packing. Bunjes et al 7 investigated TS polymorphism in solid lipid nanoparticles stabilized by a blend of saturated long-chain phospholipids and the bile salt sodium glycolate. The structures of the dispersions were investigated by DSC, WAXS and TEM.…”

Section: Discussionmentioning

confidence: 99%

“…Considering the structure of β-TS, this would correspond to the spacing between two lipid layers, i.e., 4.5 nm. 7 In Figure 4a, particle 1 thus consists of a first group of four lipid layers (about 15 nm) with two additional smaller layers on top, each creating a step of about 5 nm, for a total thickness of about 25 nm. Particle 2 consists of a first group of three lipid layers (about 10 nm) with an additional smaller layer on the top (5 nm) for a total thickness of about 15 nm.…”

Section: Particle Sizementioning

confidence: 99%

“…For instance, the use of unmodified soybean lecithin leads to the formation of β-tristearin during the preparation of SLNs, while the use of hydrogenated fully saturated soybean lecithin results in a predominant fraction of the metastable a-form. 7 Therefore, in the present study, the structural and physicochemical characteristics of lipid-based nanocarriers prepared from tristearin and castor oil using a hot solvent diffusion method were investigated. Complementary analytical techniques, including dynamic light scattering (DLS), differential scanning calorimetry (DSC), wide-angle X-ray scattering (WAXS), atomic force microscopy (AFM) and transmission electron microscopy (TEM and cryo-TEM) were used to provide detailed information on the morphology, structure and properties of the colloidal lipid particles.…”

Section: Introductionmentioning

confidence: 99%

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Physicochemical and morphological characterizations of glyceryl tristearate/castor oil nanocarriers prepared by the solvent diffusion method

Dora¹,

Putaux²,

Pignot-Paintrand³

et al. 2012

J. Braz. Chem. Soc.

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Neste estudo, nanocarreadores lipídicos foram preparados a partir do triestearato de glicerila e óleo de rícino em diferentes proporções pela técnica de difusão do solvente a quente. Estearato de PEG-660 ou Poloxamer 188 e lecitina de soja foram usados como surfactante e cossurfactante, respectivamente. Características estruturais e físico-químicas das partículas foram investigadas por meio de espalhamento de luz dinâmico (DLS), calorimetria exploratória diferencial (DSC), espalhamento de raios X a altos ângulos (WAXS), microscopia de força atômica (AFM) e microscopia eletrônica de transmissão (TEM e cryo-TEM). A análise por DLS indicou que partículas menores foram obtidas quando o lipídio líquido foi usado sozinho para obter as nanoemulsões (NEs). Técnicas microscópicas (TEM e cryo-TEM) mostraram que as NEs apresentaram formas esféricas, enquanto as nanopartículas lipídicas sólidas (NLSs) e os carreadores lipídicos nanoestruturados (CLNs) apresentaram formas mais complexas. As NLSs exibiram estrutura cristalina lamelar, enquanto os CLNs exibiram uma estrutura mista composta de fase cristalina lamelar em contato com compartimento oleoso. Estes experimentos contribuem para um melhor entendimento da capacidade de incorporação e liberação de fármacos destes nanocarreadores.In this study, drug delivery nanocarriers based on glyceryl tristearate and castor oil at different ratios were prepared by the hot solvent diffusion method. PEG 660-stearate or Poloxamer 188 and soybean lecithin were used as surfactant and co-surfactant, respectively. Structural and physicochemical characteristics of the particles were investigated by means of dynamic light scattering (DLS), differential scanning calorimetry (DSC), wide-angle X-ray scattering (WAXS), atomic force microscopy (AFM) and transmission electron microscopy (TEM and cryo-TEM). DLS data indicated that smaller particles were obtained when the liquid lipid was used alone to prepare nanoemulsions (NEs). TEM and cryo-TEM images showed that NEs presented spherical particles, whereas solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) presented more complex shapes. SLNs exhibited lamellar crystal structure, while NLCs displayed a hybrid structure composed of a lamellar crystalline phase in contact with a liquid oil compartment. These experiments contribute to a better understanding of the structure and release performance of these drug carrier systems.

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“…The larger ones with a rather anisometric shape can be attributed to the stable b-PPP modification. 37 The smaller ones, which appear ubiquitously in the TW-2.5 suspension, are mainly associated with the unknown PPP modification.…”

Section: Clnp-dna Complexesmentioning

confidence: 99%

Analysis of the structure of nanocomposites of triglyceride platelets and DNA

Schmiele

Knittel

Unruh

et al. 2015

Phys. Chem. Chem. Phys.

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DNA-complexes with platelet-like, cationically modified lipid nanoparticles (cLNPs) are studied with regard to the formation of nanocomposite structures with a sandwich-like arrangement of the DNA and platelets. For this purpose suspensions of platelet-like triglyceride nanocrystals, stabilized by a mixture of two nonionic (lecithin plus polysorbate 80 or poloxamer 188) and one cationic stabilizer dimethyldioctadecylammonium (DODAB), are used. The structure of the platelets in the native suspensions and their DNA-complexes, ranging from the sub-nano to the micron scale, is investigated with small-and wideangle scattering (SAXS, SANS, WAXS), calorimetry, photon correlation spectroscopy, transmission electron microscopy and computer simulations. The appearance of strong, lamellarly ordered peaks in the SAXS patterns of the DNA-complexes suggests a stacked arrangement of the nanocrystals, with the DNA being partially condensed between the platelets. This finding is supported with computer simulated small-angle scattering patterns of nanocrystal stacks, which can reproduce the measured small-angle scattering patterns on an absolute scale. The influence of the choice of the nonionic stabilizers and the amount of the cationic stabilizer DODAB on the structure of the native suspensions and the inner structure of their DNA-complexes is studied, too. Using high amounts of DODAB, lecithins with saturated acyl chains and polysorbate 80 instead of poloxamer 188 produces thinner nanocrystals, and thus decreases their repeat distances in the nanocomposites. Such nanocomposites could be of interest as DNA carriers, where the triglyceride platelets protect the sandwiched DNA from degradation.

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Visualizing the Structure of Triglyceride Nanoparticles in Different Crystal Modifications

Cited by 175 publications

References 22 publications

Recent Advances in Lipid Nanoparticle Formulations with Solid Matrix for Oral Drug Delivery

Recent Advances in Lipid Nanoparticle Formulations with Solid Matrix for Oral Drug Delivery

Physicochemical and morphological characterizations of glyceryl tristearate/castor oil nanocarriers prepared by the solvent diffusion method

Analysis of the structure of nanocomposites of triglyceride platelets and DNA

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