Novel thermosensitive small multilamellar lipid nanoparticles with promising release characteristics made by dual centrifugation.

Thermosensitive liposomes (TSLs) have great potential for the selective delivery of cytostatic drugs to the tumor site with greatly reduced side effects. Here we report the discovery and characterization of new thermosensitive small multilamellar lipid nanoparticles (tSMLPs) with unusually high temperature selectivity. Furthermore, the temperature-dependent release of the fluorescent marker calcein from tSMLPs is enhanced by human serum albumin.

Eutectic Resolves Lysolipid Paradox in Thermoresponsive Liposomes.

A better molecular understanding of the temperature-triggered drug release from lysolipid-based thermosensitive liposomes (LTSLs) is needed to overcome the recent setbacks in developing this important drug delivery system. Enhanced drug release was previously rationalized in terms of detergent-like effects of the lysolipid monostearyl lysophosphatidylcholine (MSPC), stabilizing local membrane defects upon LTSL lipid melting. This is highly surprising and here referred to as the 'lysolipid paradox,' because detergents usually induce the opposite effect─they cause leakage upon freezing, not melting.

Dual centrifugation as a novel and efficient method for the preparation of lipodisks.

Polyethylene glycol (PEG)-stabilized lipodisks have emerged as innovatiive, promising nanocarriers for several classes of drugs. Prior research underscores the important role of lipid composition and preparation method in determining the lipodisk size, uniformity, and drug loading capacity. In this study, we investigate dual centrifugation (DC) as a novel technique for the production of PEG-stabilized lipodisks.

Preparation of Nanosized Pharmaceutical Formulations by Dual Centrifugation.

Dual centrifugation (DC) is an innovative in-vial homogenization and in-vial nanomilling technique that has been in use for the preparation of liposomes for more than one decade. Since then, DC has continuously been developed for preparing various liposomes and other lipid nanoparticles including emulsions and solid lipid nanoparticles (SLNs) as well as polymersomes and nanocrystals. Improvements in equipment technology have been achieved over the past decade, so that DC is now on its way to becoming the -standard for the simple, fast, and aseptic production of lipid nanoparticles and nanocrystals in small and medium batch sizes, including the possibility of simple and fast formulation screening or bedside preparations of therapeutic nanoparticles.

Tailoring the Lamellarity of Liposomes Prepared by Dual Centrifugation.

Dual centrifugation (DC) is a new and versatile technique for the preparation of liposomes by in-vial homogenization of lipid-water mixtures. Size, size distribution, and entrapping efficiencies are strongly dependent on the lipid concentration during DC-homogenization. In this study, we investigated the detailed structure of DC-made liposomes.

On the validity of fluorimetric intracellular calcium detection: Impact of lipid components.

We investigated the effects of different lipids on the activity of the angiotensin II type 1 receptor (AT1R). As calcium plays a key role in the signaling of the AT1R, we used the calcium-sensitive fluorescence indicators fura-2 to detect intracellular calcium release upon stimulation with the agonist angiotensin II. At first sight, cells preincubated with Very low-density lipoprotein (VLDL) showed a reduced calcium release triggered by angiontensin II compared to untreated control.

Screening for Optimal Liposome Preparation Conditions by Using Dual Centrifugation and Time-Resolved Fluorescence Measurements.

Dual centrifugation (DC) is a novel in-vial homogenization technique for the preparation of liposomes in small batch sizes under gentle and sterile conditions which allows encapsulation efficiencies () for water soluble compounds of >50%. Since liposome size, size distribution (PDI), and depend on the lipid concentration used in the DC process, a screening method to find optimal lipid concentrations for a defined lipid composition was developed. Four lipid mixtures consisting of cholesterol, hydrogenated or non-hydrogenated egg PC, and/or PEG-DSPE were screened and suitable concentration ranges could be identified for optimal DC homogenization.

Small-scale preparation of perfluorocarbon-nanoemulsions utilizing dual centrifugation.

Background: Perfluorocarbon-nanoemulsions (PFC-NE) made of PFC and phospholipids (PL) by homogenization are optimal for in vivo-F labelling of monocytes and subsequently of inflamed tissues in magnetic resonance imaging (MRI). Necessary requirements for in vivo use of PFC-NE are sterility, suitable droplet sizes and the absence of immune activating liposomes, which are a typical byproduct of the homogenization process.

Methods And Results: To meet these requirements, we developed an aseptic in-vial preparation technique for PFC-NE based on dual centrifugation (DC) by testing different PFC/phospholipid ratios as well as the application of additives.

Rapid development of API nano-formulations from screening to production combining dual centrifugation and wet agitator bead milling.

Various wet ball nanomilling-screening tools for poorly soluble APIs are available which differ in their milling principle, batch size and number of samples. Here, the transferability of results from screening (small to medium-scale) to pharmaceutical production (largescale) was investigated. Wet ball milling in a dual centrifuge (DC) (10-100 mg API, 40 samples in parallel) was used to identify stable nanoformulations.

Lipoprotein turnover and possible remnant accumulation in preeclampsia: insights from the Freiburg Preeclampsia H.E.L.P.-apheresis study.

Background: Preeclampsia is a life-threatening disease in pregnancy, and its complex pathomechanisms are poorly understood. In preeclampsia, lipid metabolism is substantially altered. In late onset preeclampsia, remnant removal disease like lipoprotein profiles have been observed.

Dual centrifugation - A new technique for nanomilling of poorly soluble drugs and formulation screening by an DoE-approach.

The development of nanosuspensions of poorly soluble APIs takes a lot of time and high amount of active material is needed. In this publication the use of dual centrifugation (DC) for an effective and rapid API-nanomilling is described for the first time. DC differs from normal centrifugation by an additional rotation of the samples during centrifugation, resulting in a very fast and powerful movement of the samples inside the vials, which - in combination with milling beads - result in effective milling.

Dietary supplementation with n-3-fatty acids in patients with pancreatic cancer and cachexia: marine phospholipids versus fish oil - a randomized controlled double-blind trial.

Background: Like many other cancer patients, most pancreatic carcinoma patients suffer from severe weight loss. As shown in numerous studies with fish oil (FO) supplementation, a minimum daily intake of 1.5 g n-3-fatty acids (n-3-FA) contributes to weight stabilization and improvement of quality of life (QoL) of cancer patients.

The molecular mechanism by which saturated lysophosphatidylcholine attenuates the metastatic capacity of melanoma cells.

Lysophophatidylcholine (LysoPC) is an abundant constituent in human plasma. Patients with malignant cancer diseases have attenuated LysoPC plasma levels, and thus LysoPC has been examined as a metabolic biomarker for cancer prediction. Preclinical studies have shown that solid tumor cells drastically degrade LysoPCs by incorporating their free fatty acids into cell membrane phospholipids.

Saturated and mono-unsaturated lysophosphatidylcholine metabolism in tumour cells: a potential therapeutic target for preventing metastases.

Background: Metastasis is the leading cause of mortality in malignant diseases. Patients with metastasis often show reduced Lysophosphatidylcholine (LysoPC) plasma levels and treatment of metastatic tumour cells with saturated LysoPC species reduced their metastatic potential in vivo in mouse experiments. To provide a first insight into the interplay of tumour cells and LysoPC, the interactions of ten solid epithelial tumour cell lines and six leukaemic cell lines with saturated and mono-unsaturated LysoPC species were explored.

Immuno-magnetoliposomes targeting activated platelets as a potentially human-compatible MRI contrast agent for targeting atherothrombosis.

To detect unstable atherosclerotic plaques early and noninvasively would be of great clinical interest. Activated platelets are an interesting molecular target for detecting early lesions or unstable plaques. We therefore developed an MRI contrast agent consisting of magnetoliposomes (ML) linked to an antibody (anti-LIBS) specifically targeting the ligand-induced binding site of the activated GPIIb/IIIa receptor of platelets.

[Importance of long chain omega-3 fatty acids in prostate cancer].

The benefits of long chain polyunsaturated omega-3 fatty acids (n-3 PUFA) from fish or administered as supplements remain controversial regarding prostate cancer (PCa). Based on the currently available evidence no clear benefit of n-3 PUFA intake to generally reduce PCa incidence has been found. On the other hand n-3 PUFAs have a clear influence on the development of already existing PCa.

Click modification of multifunctional liposomes bearing hyperbranched polyether chains.

Aiming at controlled modification of liposomal surface structures, we describe a postpreparational approach for surface derivatization of a new type of multifunctional, sterically stabilized liposomes. Application of dual centrifugation (DC) resulted in high encapsulation efficiencies above 50% at very small batch sizes with a total volume of 150 μL, which were conductive to fast and efficient optimization of variegated surface modification reactions. Cholesterol-polymer amphiphiles, including complex hyperbranched polyether structures bearing 1-4 terminal alkynes, were used in DC formulations to provide steric stabilization.

Effects of Marine Phospholipids Extract on the Lipid Levels of Metastatic and Nonmetastatic Prostate Cancer Patients.

High intake of omega-3 fatty acids (n-3 FAs) from fish has shown to reduce metastatic progression of prostate cancer. This clinical trial investigated the influence of high n-3 FA intake (marine phospholipids, MPL) on the FA composition of blood lipids, lysophosphatidylcholine (LPC), and on lipoproteins in prostate cancer patients and elderly men without prostate cancer. MPL supplementation resulted in a significant increase of n-3 FAs (eicosapentaenoic and docosahexaenoic acid) in blood lipids, while arachidonic acid (n-6 FA) decreased significantly.

Health effects of dietary phospholipids.

Beneficial effects of dietary phospholipids (PLs) have been mentioned since the early 1900's in relation to different illnesses and symptoms, e.g. coronary heart disease, inflammation or cancer.

Lysophosphatidylcholine pretreatment reduces VLA-4 and P-Selectin-mediated b16.f10 melanoma cell adhesion in vitro and inhibits metastasis-like lung invasion in vivo.

Lysophosphatidylcholine (LysoPC) is an important intermediate in degradation and biosynthesis of phosphatidylcholine (PC). Reduced plasma LysoPC levels observed in patients with advanced cancer indicate a deregulation of LysoPC metabolism in metastasis. Recent data showed strong antimetastatic effects of liposomes consisting of saturated PC in a murine pancreatic metastasis model.

Metastasizing, Luciferase Transduced MAT‑Lu Rat Prostate Cancer Models: Follow up of Bolus and Metronomic Therapy with Doxorubicin as Model Drug.

The most fatal outcomes of prostate carcinoma (PCa) result from hormone-refractory variants of the tumor, especially from metastatic spread rather than from primary tumor burden. The goal of the study was to establish and apply rat MAT-Lu prostate cancer tumor models for improved non-invasive live follow up of tumor growth and metastasis by in vivo bioluminescence. We established luciferase transduced MAT-Lu rat PCa cells and studied tumor growth and metastatic processes in an ectopic as well as orthotopic setting.

FRET imaging of cells transfected with siRNA/liposome complexes.

By monitoring the efficiency of fluorescence resonance energy transfer of dyes attached to the different strands of siRNA, the structural integrity of the latter can be traced inside cells. Here, the experimental details of dye-labeled siRNA construction, tissue culture, and transfection with liposomally formulated siRNAs are given, as well as the conditions for confocal microscopy and an algorithm allowing the visualization of intact siRNA after image data treatment. The method allows rapid screening of different liposomal siRNA formulations, obtained by small scale dual asymmetric centrifugation with high entrapping efficiency.