Lipid-based Delivery Systems Research Articles

Citrem-phosphatidylcholine nano-self-assemblies: solubilization of bupivacaine and its role in triggering a colloidal transition from vesicles to cubosomes and hexosomes.

Improvement of pain management strategies after arthroscopic surgery by multimodal analgesia may include the use of long-acting amide local anesthetics. Among these anesthetics, the low molecular weight local anesthetic agent bupivacaine (BUP) is attractive for use in postoperative pain management. However, it has a relatively short duration of action and imposes a higher risk of systemic toxicity at relatively large bolus doses. Bupivacaine encapsulation in lipid-based delivery systems is an attractive strategy for prolonging its local anaesthetic effect and reducing the associated undesirable systemic side effects. Here, we discuss the potential development of liquid crystalline nanocarriers for delivering BUP by using a binary lipid mixture of citrem and soy phosphatidylcholine (SPC) at different weight ratios. The produced safe-by-design family of citrem/SPC nanoparticles is attractive for use in the development of nanocarriers owing to the previously reported hemocompatibility. BUP encapsulation efficiency (EE), depending on the lipid composition, was in the range of 65-77%. In this study, nanoparticle tracking analysis (NTA) and synchrotron small-angle X-ray scattering (SAXS) were employed to gain insight into the effect of BUP solubilization and lipid composition on the size and structural characteristics of the produced citrem/SPC nanodispersions. BUP loading led to a slight change in the mean sizes (diameters) and size distributions of citrem/SPC nanoparticles. However, we found that BUP accommodation into the self-assembled interiors of nanoparticles, triggers significant structural alterations in BUP concentration- and lipid composition-dependent manners, which involve vesicle-cubosome and vesicle-hexosome transitions. The structural tunability of citrem/SPC nanoparticles and the implications for potential applications in intra-articular BUP delivery are discussed.

Poly(lactic acid) nanoparticles and cell-penetrating peptide potentiate mRNA-based vaccine expression in dendritic cells triggering their activation

Messenger RNA-based vaccines have the potential to trigger robust cytotoxic immune responses, which are essential for fighting cancer and infectious diseases like HIV. Dendritic Cells (DCs) are choice targets for mRNA-based vaccine strategies, as they link innate and adaptive immune responses and are major regulators of cytotoxic and humoral adaptive responses. However, efficient delivery of antigen-coding mRNAs into DC cytosol has been highly challenging. In this study, we developed an alternative to lipid-based mRNA delivery systems, using poly(lactic acid) nanoparticles (PLA-NPs) and cationic cell-penetrating peptides as mRNA condensing agent. The formulations are assembled in two steps: (1) formation of a polyplex between mRNAs and amphipathic cationic peptides (RALA, LAH4 or LAH4-L1), and (2) adsorption of polyplexes onto PLA-NPs. LAH4-L1/mRNA polyplexes and PLA-NP/LAH4-L1/mRNA nanocomplexes are taken up by DCs via phagocytosis and clathrin-dependent endocytosis, and induce strong protein expression in DCs in vitro. They modulate DC innate immune response by activating both endosome and cytosolic Pattern Recognition Receptors (PRRs), and induce markers of adaptive responses in primary human DCs in vitro, with prevalent Th1 signature. Thus, LAH4-L1/mRNA and PLA-NP/LAH4-L1/mRNA represent a promising platform for ex vivo treatment and mRNA vaccine development.

A new lipid-based oral delivery system of erythromycin for prolong sustain release activity

Erythromycin-loaded solid lipid microparticles (SLM) based on solidified reverse micellar solution (SRMS) as an oral delivery formulation was studied. Hot homogenization technique was employed to prepare erythromycin stearate-loaded SLMs using blends of Softisan® 154 and Phospholipon® 90H or beeswax in the ratio of 1:2, and characterized in vitro. Antibacterial evaluation of the formulations was carried out by agar diffusion technique against some selected clinical isolates of bacterial. Preliminary pharmacokinetic study was performed after oral administration in male Albino rats. The results of matrix contain Softisan® 154 and phospholipon® 90H (1:2) showed that erythromycin-loaded SLM was smooth; particle size ranged from 10.3 ± 11.24 μm to 18.1 ± 10.11 μm and maximum encapsulation efficiency and loading capacity were 95.11 ± 0.3% and 43.22 ± 0.1 mg, respectively. While that of beeswax- containing matrix showed maximum particle size of 18.9 ± 21.10 μm, maximum encapsulation efficiency of 89.01 ± 0.11% and loading capacity of 39.02 ± 0.12 mg. All the formulations had prolonged release and antibacterial activity. Significantly (p > 0.05), prolonged plasma erythromycin concentration was obtained in the optimized formulation (>14 h) compared with commercial sample of erythromycin tablet (10h). Erythromycin stearate-loaded SLMs formulation could serve as an alternative to conventional oral formulation of erythromycin.

A novel method for conjugating the terminal amine of peptide ligands to cholesterol: synthesis iRGD-cholesterol.

Conventional conjugation reactions often involve the use of activated PEG as a linker, but concerns about PEG-mediated reduction in intracellular delivery and enhanced immunogenicity have generated interest in developing methods that eliminate the need for a PEG linker. Reaction conditions were identified that specifically couples the terminal amine of a cyclic iRGD peptide (CRGDRGPDC) to the hydroxyl moiety of cholesterol through a short carbamate linker. Using this method for synthesizing iRGD-cholesterol, peptide ligands can be incorporated into lipid-based delivery systems, thereby eliminating concerns about adverse reactions to PEG. Toxicity and stability data indicate low toxicity and adequate serum stability at low ligand levels.

Formulation of Insulin Self Nanoemulsifying Drug Delivery System and Its In Vitro-In Vivo Study

Particulate delivery system can be used for improving the efficacy of protein and peptide drug. In addition to a polymer-based particulate delivery system, self-nanoemulsifying drug delivery system (SNEDDS), a lipid-based delivery system, is currently developed for either less water-soluble or soluble drugs. This study aims to design SNEDDS for oral insulin administration and its in vitro-in vivo study. The SNEDDS template was designed using D-optimal mixture design and was analyzed using software Design Expert 7.1.5. The obtained optimum template was loaded with insulin and evaluated for its transmittance percentage, emulsification time, particle size, zeta potential, stability, the amount of insulin in vitro diffused across rat intestine, and insulin serum concentration after oral administration. The study results revealed that the optimum template of SNEDDS formula consisted of 10% (w/w) Miglyol 812N, 65% (w/w) Tween 80, and 25% (w/w) propylene glycol. These optimum template then was loaded with insulin and characterized. SNEDDS insulin has particle size of 12.0±1.7 nm, zeta potential of +0.16mV, transmittance of >90%, and emulsification time of < 60 seconds. The stability study showed that SNEDDS insulin was stable from both precipitation and phase separation. The amount of insulin transported from SNEDDS formula in vitro was 32.45±2.03% and non-SNEDDS formula was 10.44±5.04%. In vivo study of SNEDDS insulin produced a significantly increased Cmax, AUC, and F value than insulin non SNEDDS (p < 0.05). In brief, SNEDDS formulation in this study is a promising approach to increase the effectiveness of oral insulin. Insulin is better given orally in SNEDDS formulation than in non SNEDDS formulation.

Anti-Aging Efficacy of Melatonin-Based Cream: Clinical and Instrumental Skin Evaluation

Melatonin is a potent mitochondrial, cytoprotective and antioxidant molecule with potentially strong anti-aging properties. Topical melatonin has been shown to improve the clinical signs of skin aging. Melatosphere™ is a new lipid-based delivery system able to improve stability and skin penetration of melatonin when used in topical formulations. No clinical studies, using objective instrumental data, are available so far regarding the positive effect of Melatosphere™ in improving wrinkles in women with mild to moderate skin aging. In an open prospective, evaluator-blinded trial, we evaluate the effects on skin texture of two months of treatment with a Melatosphere™-based cream. Fifteen women aged &gt;45 years with mild to moderate facial skin aging (Glogau score 2–4) participated in the trial, after providing their informed consent. An ANTERA 3D computer-assisted skin analysis evaluation for the assessment of coarse and fine wrinkles of the periorbital area and melanin content was performed at baseline and after two months of treatment. An evaluator-blinded Investigator Global Assessment (IGA) of skin elastosis, roughness, level of dyschromia, skin dryness and the presence of actinic damage was also performed at the same time points using a four-grade score from 0 (no sign) to 3 (severe sign). At baseline, the mean (SD) IGA score was 8.2 (1.0). After two months, the IGA score significantly decreased to 4.2 (1.4) (49% reduction) (p = 0.0007). ANTERA 3D evaluations showed a significant reduction in the coarse and fine wrinkle volume in the target area of −31% and −18%, respectively. Melanin content was reduced significantly by −17%. Topical melatonin carried in Melatosphere™ improves, in the short term, signs of skin aging evaluated clinically and using the ANTERA 3D device in women with mild to moderate skin aging.

Formulation and Investigation of a Lipid Based Delivery System Containing Antimicrobials for the Treatment of Periodontal Disease.

Periodontitis is a chronic inflammatory disease, which affects the supporting tissues of the teeth, and without proper treatment it may lead to tooth loss. Antibiotics - administered orally - have been widely used in the treatment of periodontitis. With the conventional administration routes, adequate drug levels cannot be reached in the periodontal pockets and oral application of antimicrobials could lead to side effects. Drug delivery systems containing antibiotics, administered at the site of infection, could possibly help eliminate pathogen bacteria and treat periodontitis. The aim of the recent study was to create a locally swellable, biodegradable, biocompatible, mucoadhesive, lipophilic drug delivery system containing antimicrobial drugs which softens at body temperature, accommodate to the shape of the periodontal pocket and can provide extended drug release for at least one week. During the formulation, thermoanalytical, consistency, wettability, swelling, degradation and drug release studies were applied to determine the ideal ratios of lipid bases, structure-building components and surface active agent concentrations. The structure-building component cetostearyl alcohol appeared to be the most convenient, thanks to its wettability and mechanical properties, which led to controlled drug release. With the use of ideal concentrations of components (10% surfactant, 40% structure-building component, 32 % lipid base, 15% antimicrobial agent and 3% polymer), sustained drug release can be provided up to nearly 3 weeks.

Lipid-based pulmonary delivery system: a review and future considerations of formulation strategies and limitations.

Inhalation therapy of lipid-based carriers has great potential in direct target towards the root of respiratory diseases, which make them superior over other drug deliveries. With the successful entry of lipid carriers into the target cells, drugs can be absorbed in a sustained release manner and yield extended medicinal effects. Nevertheless, translation of inhalation therapy from laboratory to clinic especially in drug delivery remains a key challenge to the formulators. An ideal drug vehicle should safeguard the drugs from any premature elimination, facilitate cellular uptake, and promote maximum drug absorption with negligible toxicity. Despite knowing that lung treatment can be done via systemic delivery, pulmonary administration is capable of enhancing drug retention within the lungs, while minimizing systemic toxicity with local targeting. Current inhalation therapy of lipid-based carriers can be administered either intratracheally or intranasally to reach deep lung. However, the complex dimensions of lung architectural and natural defense mechanism poise major barriers towards targeted pulmonary delivery. Delivery systems have to be engineered in a way to tackle various diseases according to their biological conditions. This review highlights on the developmental considerations of lipid-based delivery systems cater for the pulmonary intervention of different lung illnesses.

Dendritic peptide bolaamphiphiles for siRNA delivery to primary adipocytes

Obesity is a major risk factor for diabetes, heart disease and other health problems. Adipose tissue plays a central role in the development of obesity and obesity-associated diseases. Gene therapy targeting adipose tissue may provide a promising strategy for obesity treatment. However, nucleic acid delivery to adipose tissue or even cultured adipocytes is challenging due to low delivery efficacy and high toxicity of the current cationic lipid based delivery systems, or monoamphiphiles. Herein, we report using dendritic peptide bolaamphiphiles (bolas) to deliver siRNA to primary adipocytes and hepatocytes. The bola consists of two l-Lysine dendrons connected to a fluorocarbon core through disulfide linkages. The Lysine dendrons are functionalized with l-histidine and l-tryptophan to promote endosomal escape and cellular uptake. The bola exhibited over 70% knockdown of GAPDH gene in both primary adipocytes and hepatocytes. Importantly, different from Lipofectamine that significantly reduced genes involved in lipolysis, lipogenesis, fatty acid oxidation and ketogenesis, the bolas had little to no effect on these genes. These results demonstrate the bola as a promising new vector for clinical and experimental applications for delivery of siRNA to metabolic organs.

In Vivo Introduction of mRNA Encapsulated in Lipid Nanoparticles to Brain Neuronal Cells and Astrocytes via Intracerebroventricular Administration.

Gene therapy is a promising strategy for curing certain types of brain diseases. Supplementation of therapeutic proteins such as aromatic amino acid decarboxylase (AADC) or nerve growth factor (NGF) have been reported to be successful examples of such treatments. However, there are safety concerns because these systems are based on virus-based gene vectors. A safe and efficient artificial carrier is thus urgently needed as an alternative. In this study, an mRNA based artificial gene carrier was introduced into the mouse brain via intracerebroventricular administration. As a carrier, a lipid nanoparticle (LNP) composed of environmentally sensitive lipid-like materials called an SS-cleavable proton-activated lipid-like material is used. The apolipoprotein E mediated cellular uptake of the lipid nanoparticles is one of the key features for its superior and homogeneous transfection activity compared to commercially available transfection reagents in both in vitro and in vivo situations. Immunostaining of brain specimens suggested that exogenous proteins can be introduced into neuronal cells as well as astrocytes using the mRNA-based gene carrier. This cannot be achieved using DNA-based artificial gene carriers. The findings suggest that a combination of an mRNA and a lipid based delivery system have great promise as a platform for the treatment of brain disorders.

Characterization of Self-Emulsifying Drug Delivery Systems Using In Situ Raman Spectroscopy to Study the Precipitation Inhibition Mechanism of Poorly Water-Soluble Drugs

The goal of this research was to study the molecular interactions in situ between actives and surfactants in self-emulsifying delivery systems (SEDDS) in order to illuminate the factor(s) and how they influence the drug performance in these systems. We have developed an approach to evaluate the mechanism of performance of SEDDS formulations using an in situ Raman technique. Self-emulsifying delivery systems for seven actives with different physicochemical properties were formulated. One gram of the SEDDS was dispersed in 100 mL of media, and the precipitation behavior of the actives was noted. Using an immersion probe, these dispersions were tested continuously and spectra were obtained to determine the drug-excipient interactions. The changes in the molecular vibrational peaks confirmed that the drug-TPGS hydrogen bonding was responsible for maintaining the drug in solution. The interaction between Labrasol and the actives was weak and broke upon dispersion leading to precipitation of the drug. Also, the hydrogen bond donor strength of the functional group gave a good indication of the bond strength between TPGS and the drugs which determined the performance of the actives in the system. It could be suggested that the hydrogen bond strength correlates well to the precipitation behavior from the SEDDS dispersions. Thus, studying the structures and physicochemical properties of the drug candidates and the excipients could significantly minimize the steps involved in developing successful lipid-based delivery systems.

Preformulation studies to guide the development of raloxifene lipid-based delivery systems

This study sought to evaluate raloxifene hydrochloride (RLX) solubility and compatibility with lipid excipients (oils, water-soluble and water-insoluble surfactants) with a view of assisting in the proper choice of excipients in the development of lipid-based drug delivery systems. Drug–lipid excipient compatibility was studied using thermal analysis (differential scanning calorimetry and thermogravimetry), and isothermal stress testing (IST) with a validated HPLC method. Drug solubility was determined using equilibrium solubility and pharmacopoeial methods. Among the eleven studied excipients, sunflower oil and soy lecithin presented clear signs of thermal interaction and reduction in the stability of RLX, while mixtures containing emulium® 22 showed a significant reduction in drug content. These three materials were considered incompatible with RLX. The solubility study revealed that RLX has higher solubility in castor oil and in its derivative, polyethoxylated castor oil. Plurol Isostearique® showed the best result among the water-insoluble surfactants. Thermal analysis associated with accelerated IST studies and together with solubility determinations have been shown to be a valuable strategy for the development of lipid-based drug delivery systems containing RLX.

Cationic lipid-based nanoparticles mediate functional delivery of acetate to tumor cells in vivo leading to significant anticancer effects.

Metabolic reengineering using nanoparticle delivery represents an innovative therapeutic approach to normalizing the deregulation of cellular metabolism underlying many diseases, including cancer. Here, we demonstrated a unique and novel application to the treatment of malignancy using a short-chain fatty acid (SCFA)-encapsulated lipid-based delivery system – liposome-encapsulated acetate nanoparticles for cancer applications (LITA-CAN). We assessed chronic in vivo administration of our nanoparticle in three separate murine models of colorectal cancer. We demonstrated a substantial reduction in tumor growth in the xenograft model of colorectal cancer cell lines HT-29, HCT-116 p53+/+ and HCT-116 p53−/−. Nanoparticle-induced reductions in histone deacetylase gene expression indicated a potential mechanism for these anti-proliferative effects. Together, these results indicated that LITA-CAN could be used as an effective direct or adjunct therapy to treat malignant transformation in vivo.

Characterization of a Liquid Crystal System for Sustained Release of a Peptide BMS-686117.

Liquid crystal lipid-based formulations are an effective approach to prolong pharmacokinetics and reduce burst release of a drug on subcutaneous delivery. The objective of this paper was to investigate the influence of phase structures of a lipid-based liquid crystal delivery system and its associated mechanical properties on the release profile of a peptide. It was hypothesized that release of drug molecules are closely related to the mechanical properties that are controlled by phase structures. Experimentally, the relationship between phase structures of lipid liquid crystal system-soy phosphatidyl choline (SPC) and glycerol dioleate (GDO) in water were characterized by polarized light microscopy and small angle X-ray diffraction. Their rheological properties were evaluated with a rheometer and the in vitro release of the peptide as a measure drug release from the LC-depot injection. Three phases: disordered phase, lamellar phase, mixtures of cubic, lamellar, and hexagonal phases were detected by varying formulation compositions. A significant difference in rheological behavior was observed. The disordered phase displayed some attributes of typical Newtonian fluid with lowest viscosity while the lamellar phase showed a shear thinning behavior. Regarding the mechanical strength, the lamellar phase presents the highest storage modulus due to its layer structure followed by mixed phases. Comparing release profiles, the lamellar phase produced a fast release followed by the mixture of phases. In conclusion, this study demonstrates the ability to characterize LC phase structures with microscopy, small angle X-ray diffraction, and rheological measurements and their link to modulating a peptide release profile.

Budesonide self-nanoemulsion formulation as an oral drug delivery system: preparation, characterization and cytotoxicity studies

Lipophilic drugs which are poorly water soluble need specific applications like lipid based delivery systems to increase their oral absorption across gastrointestinal tract. Selfnanoemulsifying drug delivery systems are Lipid Based Drug Delivery systems (SNEEDs) and are consists of an isotropic mixture of oil, surfactant(s) and co-surfactant. This drug delivery systems are prepared at room temperature with gentle stirring process without using any other component or heating process and become nanoemulsion form upon gentle agitation in aqueous phase. SNEDDs have many advantages such as they can be produced easily and they are affected less from other outside factors, its scaleup process is easy, unaffected by lipid digestion, carry and protect peptides which can be enzymatically hydrolyzed. The aim of this study was to increase solubility of Budesonide by using new Snedds formulation approach.

Transformation of Biopharmaceutical Classification System Class I and III Drugs Into Ionic Liquids and Lipophilic Salts for Enhanced Developability Using Lipid Formulations

Higher lipid solubility of lipophilic salt forms creates new product development opportunities for high-dose liquid-filled capsules. The purpose of this study is to determine if lipophilic salts of Biopharmaceutical Classification System (BCS) Class I amlodipine and BCS Class III fexofenadine, ranitidine, and metformin were better lipid formulation candidates than existing commercial salts. Lipophilic salts were prepared from lipophilic anions and commercial HCl or besylate salt forms, as verified by 1H-NMR. Thermal properties were assessed by differential scanning calorimetry and hot-stage microscopy. X-ray diffraction and polarized light microscopy were used to confirm the salt's physical form. All lipophilic salt forms were substantially more lipid-soluble (typically >10-fold) when compared to commercial salts. For example, amlodipine concentrations in lipidic excipients were limited to <5-10 mg/g when using the besylate salt but could be increased to >100 mg/g when using the docusate salt. Higher lipid solubility of the lipophilic salts of each drug translated to higher drug loadings in lipid formulations. In vitro tests showed that lipophilic salts solubilized in a lipid formulation resulted in dispersion behavior that was at least as rapid as the dissolution rates of conventional salts. This study confirmed the applicability of forming lipophilic salts of BCS I and III drugs to promote the utility of lipid-based delivery systems.

Nanosomal Docetaxel Lipid Suspension: A Guide to Its Use in Cancer.

Nanosomal docetaxel lipid suspension (NDLS) [DoceAqualip] is a novel formulation of docetaxel approved in India for the treatment of breast cancer, hormone-refractory prostate cancer, locally advanced squamous cell carcinoma of the head and neck, non-small cell lung cancer and advanced gastric adenocarcinoma. The lipid-based delivery system of NDLS eliminates the need for polysorbate 80 and ethanol, which are contained in the conventional docetaxel formulation and are associated with hypersensitivity reactions and infusion-related toxicities. Because of the diminished potential for NDLS to cause hypersensitivity reactions compared with conventional docetaxel, corticosteroid premedication is not required with NDLS. In a randomized trial in patients with pretreated, locally advanced or metastatic breast cancer, the overall response rate was numerically higher with NDLS than with conventional docetaxel, and post-dose adverse events in the NDLS group were considered manageable and most resolved without sequelae, despite the lack of corticosteroid premedication.

Improving In Vivo Efficacy of Bioactive Molecules: An Overview of Potentially Antitumor Phytochemicals and Currently Available Lipid-Based Delivery Systems.

Cancer is among the leading causes of morbidity and mortality worldwide. Many of the chemotherapeutic agents used in cancer treatment exhibit cell toxicity and display teratogenic effect on nontumor cells. Therefore, the search for alternative compounds which are effective against tumor cells but reduce toxicity against nontumor ones is of great importance in the progress or development of cancer treatments. In this sense, scientific knowledge about relevant aspects of nutrition intimately involved in the development and progression of cancer progresses rapidly. Phytochemicals, considered as bioactive ingredients present in plant products, have shown promising effects as potential therapeutic/preventive agents on cancer in several in vitro and in vivo assays. However, despite their bioactive properties, phytochemicals are still not commonly used in clinical practice due to several reasons, mainly attributed to their poor bioavailability. In this sense, new formulation strategies are proposed as carriers to improve their bioefficacy, highlighting the use of lipid-based delivery systems. Here, we review the potential antitumoral activity of the bioactive compounds derived from plants and the current studies carried out in animal and human models. Furthermore, their association with lipids as a formulation strategy to enhance their efficacy in vivo is also reported. The development of high effective bioactive supplements for cancer treatment based on the improvement of their bioavailability goes through this association.

Review on the formulation considerations needed to produce a stable Self micro Emulsifying Drug Delivery System (SMEDDS)

Ease of administration and painless approach made oral route the most preferred. Poor oral bioavailability is pronounced with the majority of recent active ingredients because of dissolution rate limited absorption. Failure to attain intended therapeutic effect of the poor water soluble drugs by this route led to development of novel drug delivery systems which will fulfill therapeutic needs with minimum dose. Although many formulation approaches like solid dispersions, complexation, pH modifications and lipid based delivery systems finding increased appliance with the apparent increase in absorption of drug. Among lipid based formulations, self-micro emulsifying formulations (droplet size < 100 nm) are evident to improve the oral bioavailability of hydrophobic drugs primarily due to their efficiency in facilitating solubilization and in presenting the hydrophobic drug in solubilized form whereby dissolution process can be circumvented. Various components that are used to formulate these dosage forms like surfactants and lipids contribute to the overall improvement in oral bioavailability via promoting the lymphatic transport; thereby hepatic first pass metabolism can be surmounted. The present article gives exhaustive information on the formulation design and characterization of SMEDDS by which the bioavailability can be improved. In this review article, the various aspects of pharmaceutical SMEDDS where compiled together and target audience are specifically the B. Pharm and M. Pharm students so that their knowledge towards the subject concern can be enhanced and also at the same time can be motivated towards the publication.

Fast therapeutic DNA internalization – A high potential transfection system based on a peptide mimicking cationic lipid

The delivery of nucleic acids into cells is a determining factor for successful gene therapy. In this study we investigate the uptake and time dependent processing of a lipid-based non-viral nucleic acid delivery system composed of a peptide-mimicking cationic lipid (N-{6-amino-1-[N-(9Z)-octadec-9-enylamino]-1-oxohexan-(2S)-2-yl}-N′-{2-[N,N-bis(2-aminoethyl)amino]ethyl}-2-hexadecylpropandiamide - OH4) and a phospholipid (1,2-dioleoyl-sn-glycero-3-phosphoethanolamine - DOPE). Studies by confocal laser scanning microscopy (CLSM) indicate a rapid internalization of fluorescent labelled DNA within 1h. Furthermore, vesicular structures on the lipid surface were reported, which are associated with the application of the lipid-based non-viral vector. Time dependent investigations of the gene expression of a reporter gene encoding for enhanced green fluorescent protein (eGFP) or luciferase in 4 different cell lines demonstrate an initial gene expression soon after 4h followed by a boost in gene expression beginning from 12h to 24h. Investigations with selective blocking of endocytic pathways using low molecular weight inhibitors suggested clathrin-mediated endocytosis as main internalization route in 3 cell lines. Our research presents a new horizon in rapid gene therapy using non-viral vectors; due to the modifications of the lipid components, fast nucleic acid internalizations could be achieved using our delivery systems.