Mefenamic acid (MFA) is used as an anti-inflammatory, antinociceptive, and antipyretic agent for treatment of a wide range of pathological disorders. While the uncertainty of its safety and the poor oral bioavailability constitute the major limiting factors of its medical use, considerable efforts including liposomal encapsulation are needed to achieve maximum therapeutic advantages. The current work was conducted to investigate the ultrastructural alterations in the liver induced by free MFA and its liposomal preparation. Female Sprague-Dawley rats were treated with daily oral doses of either free MFA or MFA entrapped in Tween 80 inoculated liposomes at the concentration of 80 mg/kg for 28 days. Ultrathin sections were prepared from biopsies taken from the liver of each member of all animals under study and subjected to examination by transmission electron microscopy. The liver of rats that were exposed to liposomal MFA showed more ultrastructural alterations than the rats treated with the free drug. While both groups of rats demonstrated sinusoidal dilatation, Kupffer cell hyperplasia, mitochondrial damage, and nuclear alterations, rats treated with liposome-encapsulated MFA induced an increase in the multiple lysosomes formation, hepatocytic steatosis, and apoptotic activity than free MFA-treated rats. The ultrastructural findings of the present study indicate that the use of liposomal MFA induces more hepatic damage than the use of free MFA.
The relative oxidative stability of freshly prepared and stored liposomal and nanoliposomal systems of docosahexaenoic acid (DHA, 22:6 n-3) and eicosapentaenoic acid (EPA, 20:5 n-3) were investigated. The effects of organic solvents on the oxidative stability of liposomal polyunsaturated fatty acids (PUFAs) produced by two methods, the Bangham thin-film hydration (conventional rotary evaporation method and using organic solvents) and Mozafari (direct hydration and without using organic solvents) methods, were compared. The highest physicochemical stability was observed in PUFA liposomes prepared by the Mozafari method, followed by conventional liposomes and bulk PUFAs. There was no significant change in physicochemical stability during 10 months of cold storage (4°C) in the dark. Moreover, the comparison between liposomes (>200 nm) and nanoliposomes (50-200 nm) revealed that the surface charge, physical stability and oxidative stability of liposomal PUFAs increased as the size of the liposomes decreased. The differences in the oxidative stability of PUFAs may be due to the protective effects of aqueous systems, which indicate the advantage of using non-organic solvent (water and CO(2)) techniques in liposome manufacturing.
Aim: To synthesize niosomes co-encapsulating gemcitabine (GEM) and tocotrienols, and physicochemically characterize and evaluate the antipancreatic effects of the nanoformulation on Panc 10.05, SW 1990, AsPC-1 and BxPC-3 cells. Materials & methods: Niosomes-entrapping GEM and tocotrienols composed of Span 60, cholesterol and D-α-tocopheryl polyethylene glycol 1000 succinate were produced by Handjani-Vila and film hydration methods. Results: The film hydration produced vesicles measuring 161.9 ± 0.5 nm, approximately 50% smaller in size than Handjani-Vila method, with maximum entrapment efficiencies of 20.07 ± 0.22% for GEM and 34.52 ± 0.10% for tocotrienols. In Panc 10.05 cells, GEM's antiproliferative effect was enhanced 2.78-fold in combination with tocotrienols. Niosomes produced a significant ninefold enhancement in cytotoxicity of the combination, supported by significantly higher cellular uptake of GEM in the cells. Conclusion: This study is a proof of concept on the synthesis of dual-drug niosomes and their efficacy on pancreatic cancer cells in vitro.
In this work, we studied whether chondroitin sulfates and dextran sulfates (DXSs) can influence hypochlorite-induced peroxidation of phosphatidylcholine (PC) liposomes. Multilamellar liposomes (2 mg lipid/ml) were prepared in phosphate buffer, pH 7.4, with NaCl or not and exposed to reagent HOCl/ClO- (1mM) at 37 degrees C in the presence of different concentrations of chondroitin 6-sulfate (C6S), chondroitin 4-sulfate (C4S), DXS 8000, DXS 40,000, and DXS 500,000. Lipid peroxidation was assessed by thiobarbituric acid-reactive substance (TBARS) production. DXSs and C6S enhanced TBARS production in a dose-dependent manner. The decline in TBARS production at the relatively high C6S concentrations may be attributed to C4S present in C6S, since in contrast to C6S, C4S is known to react with hypochlorite. Dextrans, nonsulfated analogues of DXS, failed to modulate TBARS production. This fact indicates the important role of negatively charged sulfate groups for DXS to facilitate hypochlorite-induced peroxidation of PC liposomes. The electrostatic nature of the mechanism providing for the pro-oxidative effect of DXS was also supported by the influence of liposome surface charge and solution ionic strength on the extent of liposome peroxidation. The addition of calcium ions to the incubation mixture did not prevent the pro-oxidative action of DXS. The relevance of the results to atherogenesis is discussed.
Extracellular vesicles (EVs) are small vesicles that are naturally released by cells and play a crucial role in cell-to-cell communication, tissue repair and regeneration. As naturally secreted EVs are limited, liposomes with different physicochemical properties, such as 1,2-dioleoyl-3-trimethylammonium propane (DOTAP) and linoleic acid (LA) with modifications have been formulated to improve EVs secretion for in vitro wound healing. Various analyses, including dynamic light scattering (DLS) and transmission electron microscopy (TEM) were performed to monitor the successful preparation of different types of liposomes. The results showed that cholesterol-LA liposomes significantly improved the secretion of EVs from immortalized adipose-derived mesenchymal stem cells (AD-MSCs) by 1.5-fold. Based on the cell migration effects obtained from scratch assay, both LA liposomal-induced EVs and cholesterol-LA liposomal-induced EVs significantly enhanced the migration of human keratinocytes (HaCaT) cell line. These findings suggested that LA and cholesterol-LA liposomes that enhance EVs secretion are potentially useful and can be extended for various tissue regeneration applications.
Preparation of chitosan-coated fatty acid liposomes is often restricted by the solubility of chitosan under basic conditions. In this experiment, the preparation of chitosan-coated oleic acid (OA) liposomes using low molecular weight (LMW) chitosan (10 and 25 kDA) was demonstrated. These selected LMW chitosans are water soluble. The coating of the chitosan layer on OA liposomes was confirmed by its microscope images and physicochemical properties, such as zeta potential and the size of the liposomes. The "peeling off" effect on the surface of chitosan-coated OA liposomes was observed in the atomic force microscope images and showed the occurrence of the chitosan layer on the surface of OA liposomes. The size of the chitosan-coated liposomes was at least 20 nm smaller than the OA liposomes, and the increase of zeta potential with the increasing amount of LMW chitosan further confirmed the presence of the surface modification of OA liposomes.
We recently developed a cell-penetrating drug carrier composed of albumin (HSA) combined with palmitoyl-cyclic-(D-Arg)12. While it is possible that the palmitoyl-cyclic-(D-Arg)12/HSA enters the cell mainly via macropinocytosis, the mechanism responsible for the induction of macropinocytosis and endosomal escape remain unknown. We report herein that palmitoyl-cyclic-(D-Arg)12/HSA might interact with heparan sulfate proteoglycan and the chemokine receptor CXCR4 followed by multiple activations of the PKC/PI3K/JNK/mTOR signaling pathways to induce macropinocytosis. This result was further confirmed by a co-treatment with 70 kDa dextran, a macropinocytosis marker. Using liposomes that mimic endosomes, the leakage of 5,6-carboxyfluorescein from liposome was observed in the presence of palmitoyl-cyclic-(D-Arg)12/HSA only in the case of the anionic late endosome-like liposomes but not the neutral early endosome-like liposomes. Heparin largely inhibited this leakage, suggesting the importance of electrostatic interactions between palmitoyl-cyclic-(D-Arg)12/HSA and the late-endosomal membrane. Immunofluorescence staining and Western blotting data indicated that the intact HSA could be transferred from endosomes to the cytosol. These collective data suggest that the palmitoyl-cyclic-(D-Arg)12/HSA is internalized via macropinocytosis and intact HSA is released from the late endosomes to the cytoplasm before the endosomes fuse with lysosomes. Palmitoyl-cyclic-(D-Arg)12/HSA not only functions as an intracellular drug delivery carrier but also as an inducer of macropinocytosis.
The search for effective and non-invasive delivery modules to transport therapeutic molecules across skin has led to the discovery of a number of nanocarriers (viz.: liposomes, ethosomes, dendrimers, etc.) in the last few decades. However, available literature suggests that these delivery modules face several issues including poor stability, low encapsulation efficiency, and scale-up hurdles. Recently, carbon nanotubes (CNTs) emerged as a versatile tool to deliver therapeutics across skin. Superior stability, high loading capacity, well-developed synthesis protocol as well as ease of scale-up are some of the reason for growing interest in CNTs. CNTs have a unique physical architecture and a large surface area with unique surface chemistry that can be tailored for vivid biomedical applications. CNTs have been thus largely engaged in the development of transdermal systems such as tuneable hydrogels, programmable nonporous membranes, electroresponsive skin modalities, protein channel mimetic platforms, reverse iontophoresis, microneedles, and dermal buckypapers. In addition, CNTs were also employed in the development of RNA interference (RNAi) based therapeutics for correcting defective dermal genes. This review expounds the state-of-art synthesis methodologies, skin penetration mechanism, drug liberation profile, loading potential, characterization techniques, and transdermal applications along with a summary on patent/regulatory status and future scope of CNT based skin therapeutics.
Tocotrienol (TRF) ethosomes were developed and evaluated in vitro for potential transdermal delivery against melanoma. The optimised TRF ethosomal size ranged between 64.9 ± 2.2 nm to 79.6 ± 3.9 nm and zeta potential (ZP) between -53.3 mV to -62.0 ± 2.6 mV. Characterisation of the ethosomes by ATR-FTIR indicated the successful formation of TRF-ethosomes. Scanning electron microscopy (SEM) images demonstrated the spherical shape of ethosomes, and the entrapment efficiencies of all the formulations were above 66%. In vitro permeation studies using full-thickness human skin showed that the permeation of gamma-T3 from the TRF ethosomal formulations was significantly higher (p