Rostami, Elham; Kashanian, Soheila; Azandaryani, Abbas H; Faramarzi, Hossain; Dolatabadi, Jafar Ezzati Nazhad; Omidfar, Kobra
The present review aims to show the features of solid lipid nanoparticles (SLNs) which are at the forefront of the rapidly developing field of nanotechnology with several potential applications in drug delivery and research. Because of some unique features of SLNs such as their unique size dependent properties it offers possibility to develop new therapeutics. A common denominator of all these SLN-based platforms is to deliver drugs into specific tissues or cells in a pathological setting with minimal adverse effects on bystander cells. SLNs are capable to incorporate drugs into nanocarriers which lead to a new prototype in drug delivery which maybe used for drug targeting. Hence solid lipid nanoparticles hold great promise for reaching the goal of controlled and site specific drug delivery and hence attracted wide attention of researchers. This review presents a broad treatment of targeted solid lipid nanoparticles discussing their types such as antibody SLN, magnetic SLN, pH sensitive SLN and cationic SLN.
Jourghanian, Parisa; Ghaffari, Solmaz; Ardjmand, Mehdi; Haghighat, Setareh; Mohammadnejad, Mahdieh
Purpose: curcumin is poorly water soluble drug with low bioavailability. Use of lipid systems in lipophilic substances increases solubility and bioavailability of poorly soluble drugs. The aim of this study was to prepare curcumin loaded Solid Lipid Nanoparticles (SLNs) with high loading efficiency, small particle size and prolonged release profile with enhanced antibacterial efficacy. Methods: to synthesize stable SLNs, freeze- Drying was done using mannitol as cryoprotectant. Cholesterol was used as carrier because of good tolerability and biocompatibility. SLNs were prepared using high pressure homogenization method. Results: optimized SLNs had 112 and 163 nm particle size before and after freeze drying, respectively. The prepared SLNs had 71% loading efficiency. 90% of loaded curcumin was released after 48 hours. Morphologic study for formulation was done by taking SEM pictures of curcumin SLNs. Results show the spherical shape of curcumin SLNs. DSC studies were performed to determine prolonged release mechanism. Antimicrobial studies were done to compare the antimicrobial efficacy of curcumin SLNs with free curcumin. DSC studies showed probability of formation of hydrogen bonds between cholesterol and curcumin which resulted in prolonged release of curcumin. Lipid structure of cholesterol could cause enhanced permeability in studied bacteria to increase antibacterial characteristics of curcumin. Conclusion: the designed curcumin SLNs could be candidate for formulation of different dosage forms or cosmeceutical products. PMID:27123413
Shah, M.; Agrawal, Y. K.; Garala, K.; Ramkishan, A.
The aim of this study was to understand and investigate the relationship between experimental factors and their responses in the preparation of ciprofloxacin hydrochloride based solid lipid nanoparticles. A quadratic relationship was studied by developing central composite rotatable design. Amount of lipid and drug, stirring speed and stirring time were selected as experimental factors while particle size, zeta potential and drug entrapment were used as responses. Prior to the experimental design, a qualitative prescreening study was performed to check the effect of various solid lipids and their combinations. Results showed that changing the amount of lipid, stirring speed and stirring time had a noticeable influence on the entrapment efficiencies and particle size of the prepared solid lipid nanoparticles. The particle size of a solid lipid nanoparticle was in the range of 159-246 nm and drug encapsulation efficiencies were marginally improved by choosing a binary mixture of physically incompatible solid lipids. Release of ciprofloxacin hydrochloride from solid lipid nanoparticle was considerably slow, and it shows Higuchi matrix model as the best fitted model. Study of solid lipid nanoparticle suggested that the lipid based carrier system could potentially be exploited as a delivery system with improved drug entrapment efficiency and controlled drug release for water soluble actives. PMID:23716872
Kumar, Sacheen; Randhawa, Jaspreet Kaur
Poor solubility of newly developed drug molecules is the main problem in recent drug discovery research, so novel drug delivery approaches are being used to deliver these molecular entities for pharmacological action. Colloidal carriers (emulsion, suspensions, liposomes, polymer nanoparticles and solid lipid nanoparticles) have been used to administer poorly soluble drugs, but solid lipid nanoparticles are found to be the most reliable carriers for this type of drugs due to its advantages over other carriers. Solid lipid nanoparticles have the potential to solve the drug delivery problems with safe excipients used in its formulation. In this review all the aspects of solid lipid nanoparticles production, stability, characterization, differentiation based on route, preservation and storage have been discussed.
Noack, Andreas; Hause, Gerd; Mäder, Karsten
Curcuminoid-loaded solid lipid nanoparticles (SLN) were produced by melt-homogenization. The used lipid matrices were medium chain triglycerides, trimyristin and tristearin. The resulting nanoparticles had an anisometric shape and a platelet-like structure. Curcuminoid-loaded trimyristin particles did not solidify when stored at room temperature. The supercooled state of trimyristin was studied by DSC and (1)H NMR experiments. A partial recrystallization of the lipid matrix was detected but no change of the mobility of the lipid was noted. Nanoparticles based on tristearin had an α- and β-modification which was subsequently converted into the stable β-phase. Curcuminoids did neither influence the melting behavior nor the crystalline or geometric structure of the particles. The interactions between the curcuminoids and the lipid matrix were investigated by Raman and fluorescence spectroscopy. The shape of the curcuminoid bands in the Raman spectra suggested that the drug was in an amorphous state. The fluorescence spectra showed an effect of the lipid matrix on fluorescence properties of the curcuminoids. It was further demonstrated that the drug was not secluded by the solid lipid matrix, but it was influenced by the surrounding aqueous environment. Fluorescence anisotropy measurements revealed a decreased mobility of the curcuminoids within the nanodispersions. From the results of Raman and fluorescence measurements it was concluded that the drug was mainly located on the surface of the crystalline particles.
Ye, Jiesheng; Wang, Aihua; Liu, Chunxi; Chen, Zhijin; Zhang, Na
The objective of this study was to design novel anionic ternary nanoparticles for gene delivery. These ternary nanoparticles were equipped with protamine/DNA binary complexes (150-200 nm) as the support, and the anionic formation was achieved by absorption of anionic solid lipid nanoparticles (<=20 nm) onto the surface of the binary complexes. The small solid lipid nanoparticles (SLNs) were prepared by a modified film dispersion-ultrasonication method, and adsorption of the anionic SLNs onto the binary complexes was typically carried out in water via electrostatic interaction. The formulated ternary nanoparticles were found to be relatively uniform in size (257.7 ± 10.6 nm) with a 'bumpy' surface, and the surface charge inversion from 19.28 ± 1.14 mV to -17.16 ± 1.92 mV could be considered as evidence of the formation of the ternary nanoparticles. The fluorescence intensity measurements from three batches of the ternary nanoparticles gave a mean adsorption efficiency of 96.75 ± 1.13%. Circular dichroism spectra analysis showed that the protamine/DNA complexes had been coated by small SLNs, and that the anionic ternary nanoparticles formed did not disturb the construction of the binary complexes. SYBR Green I analysis suggested that the ternary nanoparticles could protect the DNA from nuclease degradation, and cell viability assay results showed that they exhibit lower cytotoxicity to A549 cells compared with the binary complexes and lipofectamine. The transfection efficiency of the ternary nanoparticles was better than that of naked DNA and the binary complexes, and almost equal to that of lipofectamine/DNA complexes, as revealed by inversion fluorescence microscope observation. These results indicated that the anionic ternary nanoparticles could facilitate gene transfer in cultured cells, and might alleviate the drawbacks of the conventional cationic vector/DNA complexes for gene delivery in vivo.
Naseri, Neda; Valizadeh, Hadi; Zakeri-Milani, Parvin
Lipid nanoparticles (LNPs) have attracted special interest during last few decades. Solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) are two major types of Lipid-based nanoparticles. SLNs were developed to overcome the limitations of other colloidal carriers, such as emulsions, liposomes and polymeric nanoparticles because they have advantages like good release profile and targeted drug delivery with excellent physical stability. In the next generation of the lipid nanoparticle, NLCs are modified SLNs which improve the stability and capacity loading. Three structural models of NLCs have been proposed. These LNPs have potential applications in drug delivery field, research, cosmetics, clinical medicine, etc. This article focuses on features, structure and innovation of LNPs and presents a wide discussion about preparation methods, advantages, disadvantages and applications of LNPs by focusing on SLNs and NLCs. PMID:26504751
Madureira, Ana Raquel; Campos, Débora; Gullon, Beatriz; Marques, Cláudia; Rodríguez-Alcalá, Luís M; Calhau, Conceição; Alonso, Jose Luis; Sarmento, Bruno; Gomes, Ana Maria; Pintado, Manuela
Solid lipid nanoparticles (SLNs) can be used for oral delivery of phenolic compounds in order to protect them from the harsh conditions of digestion and improve their bioavailability in the intestinal epithelium. Recently, the production and characterization of SLNs loaded with rosmarinic acid (RA) and herbal extracts was performed for future use as functional food ingredients. Diet components have been shown to have a huge impact on gut microbiota viability and metabolic activity. Hence, SLNs loaded with RA, sage and savoury extracts have been evaluated for their effect on intestinal microbiota growth and the metabolic products generated. Fermentations in anaerobic batch cultures using volunteer human faeces were performed during 24 h. Dynamic bacterial population changes were analysed using PCR-real time, as well as the generation of fatty acids and the quantification of phenolic compounds by analytical methods. Solid lipid nanoparticles released phenolic compounds at non-inhibitory bacterial growth concentrations. Released herbal extract phenolic compounds showed a beneficial effect on gut microbiota growth (e.g. bifidogenic effects) and were used as substrates. Acetate, formate, lactate and butyrate were produced in higher concentrations. The released phenolic compounds also induced PUFA and trans fatty acids metabolic activity, the production of saturated fatty acids, as well of potential beneficial conjugated linoleic acid isomers. Solid lipid nanoparticles modulate gut microbiota and metabolic activities.
Mukherjee, S.; Ray, S.; Thakur, R. S.
Solid lipid nanoparticles are at the forefront of the rapidly developing field of nanotechnology with several potential applications in drug delivery, clinical medicine and research, as well as in other varied sciences. Due to their unique size-dependent properties, lipid nanoparticles offer the possibility to develop new therapeutics. The ability to incorporate drugs into nanocarriers offers a new prototype in drug delivery that could be used for secondary and tertiary levels of drug targeting. Hence, solid lipid nanoparticles hold great promise for reaching the goal of controlled and site specific drug delivery and hence have attracted wide attention of researchers. This review presents a broad treatment of solid lipid nanoparticles discussing their advantages, limitations and their possible remedies. The different types of nanocarriers which were based on solid lipid like solid lipid nanoparticles, nanostructured lipid carriers, lipid drug conjugates are discussed with their structural differences. Different production methods which are suitable for large scale production and applications of solid lipid nanoparticles are described. Appropriate analytical techniques for characterization of solid lipid nanoparticles like photon correlation spectroscopy, scanning electron microscopy, differential scanning calorimetry are highlighted. Aspects of solid lipid nanoparticles route of administration and their biodistribution are also incorporated. If appropriately investigated, solid lipid nanoparticles may open new vistas in therapy of complex diseases. PMID:20502539
Padois, Karine; Cantiéni, Céline; Bertholle, Valérie; Bardel, Claire; Pirot, Fabrice; Falson, Françoise
Solid lipid nanoparticles have been reported as possible carrier for skin drug delivery. Solid lipid nanoparticles are produced from biocompatible and biodegradable lipids. Solid lipid nanoparticles made of semi-synthetic triglycerides stabilized with a mixture of polysorbate and sorbitan oleate were loaded with 5% of minoxidil. The prepared systems were characterized for particle size, pH and drug content. Ex vivo skin penetration studies were performed using Franz-type glass diffusion cells and pig ear skin. Ex vivo skin corrosion studies were realized with a method derived from the Corrositex(®) test. Solid lipid nanoparticles suspensions were compared to commercial solutions in terms of skin penetration and skin corrosion. Solid lipid nanoparticles suspensions have been shown as efficient as commercial solutions for skin penetration; and were non-corrosive while commercial solutions presented a corrosive potential. Solid lipid nanoparticles suspensions would constitute a promising formulation for hair loss treatment.
Priyanka, K; Sathali, A Abdul Hasan
Solid lipid nanoparticles (SLNs) are an alternative carrier system used to load the drug for targeting, to improve the bioavailability by increasing its solubility, and protecting the drug from presystemic metabolism. The avoidance of presystemic metabolism is due to the nano-metric size range, so that the liver cannot uptake the drug from the delivery system and is not metabolized by the liver. Montelukast sodium is an anti-asthmatic drug, because of its poor oral bioavailability, presystemic metabolism, and decreased half-life; it was chosen to formulate as the solid lipid nanoparticle (SLN) system by hot homogenization followed by an ultrasonication method, to overcome the above. Compritol ATO 888, stearic acid, and glyceryl monostearate were used as a lipid matrix and polyvinyl alcohol as a surfactant. The prepared formulations have been evaluated for entrapment efficiency, drug content, in vitro drug release, particle size analysis, scanning electron microscopy, Fourier transform-infrared studies (FT-IR), differential scanning calorimetry (DSC), and stability. Particle size analysis revealed that the SLN prepared from the higher melting point lipid showed a larger particle size and with increased carbon chain length of the fatty acids. Entrapment efficiency (EE) was ranging from 42% to 92%. In vitro release studies showed maximum cumulative drug release was obtained for F 1 (59.1%) containing stearic acid, and the lowest was observed for F 18 (28.1%) containing compritol ATO 888 after 12 h and all the formulations followed first-order release kinetics. FT-IR and DSC studies revealed no interaction between drug and lipids. Studies showed that increase in lipid concentration, increased particle size, EE, and maintained the sustained release of drug. Among all, compritol ATO 888 was chosen as the best lipid for formulating SLN because it had high EE and sustained the drug release. PMID:23112531
Breidenich, Jennifer; Patrone, Julia; Kelly, Lisa; Benkoski, Jason; Le, Huong; Sample, Jennifer
We report the synthesis and characterization of a novel nanoparticle formulation designed for skin penetration for the purpose of skin imaging. Solid lipid nanoparticles (SLNs), a drug delivery vehicle, were used as the matrix for targeted delivery of peroxide-sensitive chemiluminescent compounds to the epidermis. Luminol and oxalate were chosen as the chemiluminescent test systems, and a formulation was determined based upon non-toxic components, lotion-like properties, and longevity/visibility of a chemiluminescent signal. The luminescence lifetime was extended in the lipid formulation in comparison to the chemiluminescent system in solution. When applied to porcine skin, our formulation remained detectable relative to negative and positive controls. Initial MTT toxicity testing using HepG2 cells have indicated that this formulation is relatively non-toxic. This formulation could be used to image native peroxides present in tissue that may be indicative of skin disease.
Attama, Anthony A; Umeyor, Chukwuebuka E
Novel solid lipid drug delivery systems such as solid lipid nanoparticles (SLN) have attracted wide and increasing attention in recent years. It has been sought as an interesting alternative drug delivery carrier system for bioactives for a variety of delivery routes. They show major advantages such as sustained release, improved bioavailability, improved drug incorporation and very wide application. This paper presents a discussion on the production protocols of SLN, lyophilization of SLN and delivery of SLN across the blood-brain barrier. Special attention was also paid to entrapment and release of drugs from SLN and strategies to enhance drug entrapment in SLN for sustained release. Analytical methods for the characterization of SLN were also discussed. Various routes of administration of SLN were presented as well as a consideration of the ethical issues and future prospects in the production and use of SLN for sustained release of bioactives.
Patil, Hemlata; Kulkarni, Vijay; Majumdar, Soumyajit; Repka, Michael A
Solid lipid nanoparticles (SLN) can either be produced by hot homogenization of melted lipids at higher temperatures or by a cold homogenization process. This paper proposes and demonstrates the formulation of SLN for pharmaceutical applications by combining two processes: hot melt extrusion (HME) technology for melt-emulsification and high-pressure homogenization (HPH) for size reduction. This work aimed at developing continuous and scalable processes for SLN by mixing a lipid and aqueous phase containing an emulsifier in the extruder barrel at temperatures above the melting point of the lipid and further reducing the particle size of emulsion by HPH linked to HME in a sequence. The developed novel platform demonstrated better process control and size reduction compared to the conventional process of hot homogenization (batch process). Varying the process parameters enabled the production of SLN below 200 nm (for 60 mg/ml lipid solution at a flow rate of 100ml/min). Among the several process parameters investigated, the lipid concentration, residence time and screw design played major roles in influencing the size of the SLN. This new process demonstrates the potential use of hot melt extrusion technology for continuous and large-scale production of SLN.
Kathe, Niranjan; Henriksen, Brian; Chauhan, Harsh
Solid lipid nanoparticles (SLNs) are gaining importance due to numerous advantages they offer as a drug delivery system. SLN incorporate poorly soluble drugs, proteins, biologicals, etc. SLN are prepared by techniques like high-pressure homogenization, sonication and employs a wide range of lipids and surfactants. Physicochemical characterization techniques include particle size analysis, zeta potential and determination of crystallinity/polymorphism. Furthermore, drug loading and drug entrapment efficiency are common parameters used to test the efficiency of SLN. Most importantly, the functionality assay of SLN is essential to predict the activity and performance in vivo. The review presented discusses the importance of SLN in drug delivery with emphasis on principles and limitations associated with their physicochemical characterization.
Sandri, Giuseppina; Motta, Simona; Bonferoni, Maria Cristina; Brocca, Paola; Rossi, Silvia; Ferrari, Franca; Rondelli, Valeria; Cantù, Laura; Caramella, Carla; Del Favero, Elena
Solid Lipid Nanoparticles (SLNs) composed of biodegradable physiological lipids have been widely proposed as efficient drug delivery systems, also for ophthalmic administration. Recently, chitosan-associated-SLNs have been developed to further improve the residence time of these colloidal systems in the precorneal area by means of mucoadhesive interaction. In the present study, a one-step preparation protocol was used aiming both at scale-up ease and at stronger coupling between chitosan and SLNs. The resulting particles were chitosan associated-SLNs (CS-SLNs). These nanoparticles were characterized, as compared to both the chitosan-free and the usual chitosan-coated ones, by applying a multi-technique approach: light, neutron and X-ray scattering, Zeta-potential, AFM, calorimetry. It was assessed that, while keeping the features of nano-size and surface-charge required for an efficient vector, these new nanoparticles display a strong and intimate interaction between chitosan and SLNs, far more settled than the usual simple coverage. Moreover, this one-step preparation method allows to obtain a strong and intimate interaction between chitosan and SLNs, firmer than the usual simple coating. This confers to the CS-SLNs an improved mucoadhesion, opening the way for a high-performing ophthalmic formulation.
Subedi, Robhash Kusam; Kang, Keon Wook; Choi, Hoo-Kyun
Solid lipid nanoparticles (SLN) loaded with doxorubicin were prepared by solvent emulsification-diffusion method. Glyceryl caprate (Capmul)MCM C10) was used as lipid core, and curdlan as the shell material. Dimethyl sulfoxide (DMSO) was used to dissolve both lipid and drug. Polyethylene glycol 660 hydroxystearate (Solutol)HS15) was employed as surfactant. Major formulation parameters were optimized to obtain high quality nanoparticles. The mean particle size measured by photon correlation spectroscopy (PCS) was 199nm. The entrapment efficiency (EE) and drug loading capacity (DL), determined with fluorescence spectroscopy, were 67.5+/-2.4% and 2.8+/-0.1%, respectively. The drug release behavior was studied by in vitro method. Cell viability assay showed that properties of SLN remain unchanged during the process of freeze-drying. Stability study revealed that lyophilized SLN were equally effective (p<0.05) after 1 year of storage at 4 degrees C. In conclusion, SLN with small particle size, high EE, and relatively high DL for doxorubicin can be obtained by this method.
Aboutaleb, Ehsan; Noori, Massoumeh; Gandomi, Narges; Atyabi, Fatemeh; Fazeli, Mohammad Reza; Jamalifar, Hossein; Dinarvand, Rassoul
Rifampin (RIF) is one of the front-line drugs in therapy of tuberculosis (TB). The emergence of multidrug-resistant strains of mycobacteria has greatly contributed to the increased incidence of TB. Nano-based formulation of several antimicrobials has been shown to improve either antibacterial efficacy or pharmacokinetic behavior. In this study, RIF-loaded solid lipid nanoparticles (SLNs) were prepared by a modified microemulsion-based method and their particle size, zeta potential, encapsulation efficiency, morphology, and antibacterial activity against Mycobacterium fortuitum were evaluated. The resulting SLNs were spherical with diameter of about 100 nm, with low negative zeta potential, and an encapsulation efficiency of 82%. The formulation also sustained the drug release for 72 h. The antimycobacterial efficacy was greatly improved against M. fortuitum, and the minimum inhibitory concentration of drug-loaded SLNs was eight times less than free RIF. Drug-free SLNs and the ingredients showed no antibacterial effect. It can be concluded that as expected, solid lipid nanoparticles are promising vehicles for enhanced antimycobacterial effect of rifampin.
Tiyaboonchai, Waree; Tungpradit, Watcharaphorn; Plianbangchang, Pinyupa
Curcuminoids loaded solid lipid nanoparticles (SLNs) have been successfully developed using a microemulsion technique at approximately 75 degrees C. It was found that variation in the amount of ingredients had profound effects on the curcuminoid loading capacity, the mean particle size, and size distribution. At optimized process conditions, lyophilized curcuminoids loaded SLNs showed spherical particles with a mean particle size of approximately 450nm and a polydispersity index of 0.4. Up to 70% (w/w) curcuminoids incorporation efficacy was achieved. In vitro release studies showed a prolonged release of the curcuminoids from the solid lipid nanoparticles up to 12h following the Higuchi's square root model. After 6-month storage at room temperature in the absence of sunlight, the physical and chemical stabilities of the lyophilized curcuminoids loaded SLNs could be maintained, i.e. the mean particle size and the amount of curcuminoids showed no significant changes (P>0.05) compared to the freshly prepared SLNs. In addition, the chemical stability of curcuminoids incorporated into SLNs was further investigated by dispersing them into a model cream base. The results revealed that after storage in the absence of sunlight for 6 months, the percentages of the remaining curcumin, bisdemethoxycurcumin and demethoxycurcumin were 91, 96 and 88, respectively.
Chuan, Junlan; Li, Yanzhen; Yang, Likai; Sun, Xun; Zhang, Qiang; Gong, Tao; Zhang, Zhirong
The present study aimed at developing a drug delivery system targeting the densest site of tuberculosis infection, the alveolar macrophages (AMs). Rifampicin (RFP)-loaded solid lipid nanoparticles (RFP-SLNs) with an average size of 829.6 ± 16.1 nm were prepared by a modified lipid film hydration method. The cytotoxicity of RFP-SLNs to AMs and alveolar epithelial type II cells (AECs) was examined using MTT assays. The viability of AMs and AECs was above 80 % after treatment with RFP-SLNs, which showed low toxicity to both AMs and AECs. Confocal Laser Scanning Microscopy was employed to observe the interaction between RFP-SLNs and both AMs and AECs. After incubating the cells with RFP-SLNs for 2 h, the fluorescent intensity in AMs was more and remained longer (from 0.5 to 12 h) when compared with that in AECs (from 0.5 to 8 h). In vitro uptake characteristics of RFP-SLNs in AMs and AECs were also investigated by detection of intracellular RFP by High performance liquid chromatography. Results showed that RFP-SLNs delivered markedly higher RFP into AMs (691.7 ng/mg in cultured AMs, 662.6 ng/mg in primary AMs) than that into AECs (319.2 ng/mg in cultured AECs, 287.2 ng/mg in primary AECs). Subsequently, in vivo delivery efficiency and the selectivity of RFP-SLNs were further verified in Sprague-Dawley rats. Under pulmonary administration of RFP-SLNs, the amount of RFP in AMs was significantly higher than that in AECs at each time point. Our results demonstrated that solid lipid nanoparticles are a promising strategy for the delivery of rifampicin to alveolar macrophages selectively.
Fang, Jia-You; Fang, Chia-Lang; Liu, Chi-Hsien; Su, Yu-Han
Solid lipid nanoparticles (SLN) were developed by using Precirol ATO 5 as the solid core of the particles for topical psoralen delivery. Nanostructured lipid carriers (NLC) consisting of Precirol and squalene, a liquid lipid, were also prepared for comparison. SLN and NLC showed respective mean particle sizes of approximately 300 and 200nm, respectively. Viscosity, polarity, and differential scanning calorimetry (DSC) studies were performed to characterize the physicochemical properties of the SLN and NLC. The viscosity of all nanoparticulate systems exhibited Newtonian behavior except the NLC with Tween 80 and soybean phospholipids as the emulsifiers (NLC-Tw). According to the DSC thermograms, the melting peak of Precirol shifted from 58 to 55 degrees C after incorporating squalene into the solid lipid cores (of NLC), which suggests defects in the crystalline lattice of the lipid cores and smaller particle sizes. Three psoralen derivatives for psoriasis treatments were loaded in SLN and NLC to examine their ability to permeate skin. The permeability of psoralens increased in the order of 8-methoxypsoralen (8-MOP)>5-methoxypsoralen (5-MOP)>4,5,8-trimethylpsoralen (TMP). Enhanced permeation and controlled release of psoralen delivery were both achieved using the NLC. The in vitro permeation results showed that NLC-Tw increased the 8-MOP flux 2.8 times over that of a conventional emulsion. Hyperproliferative or psoriasis-like skin produced by repeated strippings in the dorsal skin of nude mouse was also used as a permeation barrier. The results showed that the entrapment of 8-MOP in nanoparticulate systems could minimize the permeation differentiation between normal and hyperproliferative skin compared to the free drug in an aqueous control.
de Jesus, Marcelo B; Radaic, Allan; Hinrichs, Wouter L J; Ferreira, Carmen V; de Paula, Eneida; Hoekstra, Dick; Zuhorn, Inge S
Solid lipid nanoparticles (SLNs) are a promising system for the delivery of lipophilic and hydrophilic drugs. They consist of a solid lipid core that is stabilized by a layer of surfactants. By the incorporation of cationic lipids in the formulation, positively charged SLNs can be generated, that are suitable carriers for nucleic acids (DNA, siRNA). Considering the beneficial effect of helper lipids on the transfection efficiency with cationic liposomes, the effect of the helper lipid 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) on transfection with cationic lipid-containing solid lipid nanoparticles was investigated in PC3 prostate cancer cells. The inclusion of DOPE in SLN formulations, instead of promoted, strongly inhibited SLN transfection efficiency, by frustrating the accommodation of DNA by the particles, as was revealed by biochemical analysis. SLNs devoid of DOPE maintained a homogenous size distribution of approximately 150 nm following lipoplex assembly and cellular delivery, and showed transfection efficiency comparable to that of Lipofectamine 2000' (LF2k). Moreover, the SLNs maintain their high transfection efficiency after lyophilization and long-term storage (1-2 years), an important asset for biomedical applications. There is even the possibility to lyophilize the SLN carrier together with its DNA cargo, which represents an interesting pharmaceutical advantage of the SLN formulations over LF2k. These results reflect marked differences between the physicochemical properties of cationic liposomes and SLNs, the latter requiring more critical lipid-depending properties for effective 'packaging' of DNA but displaying a higher storage stability than cationic lipid based carriers like LF2k.
Butani, Dhruv; Yewale, Chetan; Misra, Ambikanandan
The present work is focused on design and development of topical Amphotericin B solid lipid nanoparticles (SLNs) to improve the therapeutic antifungal activity. Amphotericin B loaded SLNs were prepared by novel solvent diffusion method and were characterized for particle size, zeta potential, drug entrapment, surface morphology, in vitro antifungal activity, ex vivo permeation, retention and skin-irritation. Optimized SLNs were spherical with average size of 111.1±2.2nm, zeta potential of -23.98±1.36mV and 93.8±1.8% of drug entrapment. Characterization of Amphotericin B SLNs by differential scanning calorimetry, Fourier transform infrared spectroscopy and Powder X-ray diffraction studies revealed absence of interaction between Amphotericin B and lipid. Amphotericin B is well dispersed in the lipid matrix without any crystallization. The SLNs were lyophilized with and without cryoprotectants to evaluate the stability and it was observed that the particle size of the SLNs significantly increased in SLN formulations lyophilized without cryoprotectant. The optimized SLN 5 formulation exhibited 2 fold higher drug permeation as compared to plain drug dispersion and higher zone of inhibition in Trichophyton rubrum fungal species. Formulation was found to be stable at 2-8°C and 25±2°C for the period of three months. Results of present study indicate that SLNs are suitable carriers for entrapment of poorly water soluble drugs and for enhancement of therapeutic efficacy of antifungal drug.
Varshosaz, J.; Ghaffari, S.; Mirshojaei, S. F.; Jafarian, A.; Atyabi, F.; Kobarfard, F.; Azarmi, S.
The main purpose of the present work was studying the biodistribution of amikacin solid lipid nanoparticles (SLNs) after pulmonary delivery to increase its concentration in the lungs for treatment of cystic fibrosis lung infections and also providing a new method for clinical application of amikacin. To achieve this aim, 99mTc labelled amikacin was loaded in cholesterol SLNs and after in vitro optimization, the desired SLNs and free drug were administered through pulmonary and i.v. routes to male rats and qualitative and biodistribution studies were done. Results showed that pulmonary delivery of SLNs of amikacin by microsprayer caused higher drug concentration in lungs than kidneys while i.v. administration of free drug caused reverse conditions. It seems that pulmonary delivery of SLNs may improve patients' compliance due to reduction of drug side effects in kidneys and elongation of drug dosing intervals due to the sustained drug release from SLNs. PMID:23984315
Jain, Sanyog; Mistry, Meghal A; Swarnakar, Nitin K
The present investigation was enthused by the possibility to develop solid lipid nanoparticles (SLNs) of hydrophilic drug acyclovir (ACV) and evaluate their potential as the carrier for dermal delivery. ACV-loaded SLNs (ACV-SLNs) were prepared by the optimized double emulsion process using Compritol 888 ATO as solid lipid. The prepared SLNs were smooth and spherical in shape with average diameter, polydispersity index, and entrapment efficiency of 262 ± 13 nm, 0.280 ± 0.01, and 40.08 ± 4.39% at 10% (w/w) theoretical drug loading with respect to Compritol 888 ATO content. Differential scanning calorimetry and powder X-ray diffraction pattern revealed that ACV was present in the amorphous state inside the SLNs. In vitro skin permeation studies on human cadaver and Sprague-Dawley rat skin revealed 17.65 and 15.17 times higher accumulation of ACV-SLNs in the dermal tissues in comparison to commercially available ACV cream after 24 h. Mechanism of topical permeation and dermal distribution was studied qualitatively using confocal laser scanning microscopy. While free dye (calcein) failed to penetrate skin barrier, the same encapsulated in SLNs penetrated deeply into the dermal tissue suggesting that pilosebaceous route was followed by SLNs for skin penetration. Histological examination and transdermal epidermal water loss measurement suggested that no major morphological changes occurred on rat skin surface due to the application of SLNs. Overall, it was concluded that ACV-loaded SLNs might be beneficial in improving dermal delivery of antiviral agent(s) for the treatment of topical herpes simplex infection.
Triplett, Michael D.; Rathman, James F.
Using statistical experimental design methodologies, the solid lipid nanoparticle design space was found to be more robust than previously shown in literature. Formulation and high shear homogenization process effects on solid lipid nanoparticle size distribution, stability, drug loading, and drug release have been investigated. Experimentation indicated stearic acid as the optimal lipid, sodium taurocholate as the optimal cosurfactant, an optimum lecithin to sodium taurocholate ratio of 3:1, and an inverse relationship between mixing time and speed and nanoparticle size and polydispersity. Having defined the base solid lipid nanoparticle system, β-carotene was incorporated into stearic acid nanoparticles to investigate the effects of introducing a drug into the base solid lipid nanoparticle system. The presence of β-carotene produced a significant effect on the optimal formulation and process conditions, but the design space was found to be robust enough to accommodate the drug. β-Carotene entrapment efficiency averaged 40%. β-Carotene was retained in the nanoparticles for 1 month. As demonstrated herein, solid lipid nanoparticle technology can be sufficiently robust from a design standpoint to become commercially viable.
Kharya, Parul; Jain, Ashish; Gulbake, Arvind; Shilpi, Satish; Jain, Ankit; Hurkat, Pooja; Majumdar, Subrata; Jain, Sanjay K.
The purpose of this study is to investigate the targeting potential of amino acid (phenylalanine)-coupled solid lipid nanoparticles (SLN) loaded with ionically complexed doxorubicin HCl (Dox). Ionic complexation was used to enhance the loading efficiency and release characteristics of water soluble form of Dox. l-Type amino acid transporters (LAT1) are highly expressed on blood brain barrier as well as on many brain cancer cells, thus targeting LAT1 using phenylalanine improved anticancer activity of prepared nanocarrier. The phenylalanine-coupled SLN were characterized by fourier transform infrared spectroscopy, scanning electron microscope, transmission electron microscopy, particle size, zeta potential, entrapment efficiency and in vitro release. The particle size of the resulting SLN was found to be in the range of 163.3 ± 5.2 to 113.0 ± 2.6 nm, with a slightly negative surface charge. In ex vivo study on C6 glioma cell lines, the cellular cytotoxicity of the SLN was highly increased when coupled with phenylalanine. In addition, stealthing sheath of PEG present on the surface of the SLN enhanced the cellular uptake of the SLN on C6 glioma cell line. Results of biodistribution and fluorescence studies clearly revealed that phenylalanine-coupled SLN could deliver high amount of drug into the brain tumor cells and showed the brain-targeting potential.
Jiang, Shan; Zhu, Rongrong; He, Xiaolie; Wang, Jiao; Wang, Mei; Qian, Yechang; Wang, Shilong
Curcumin (Cur) is a promising photosensitizer that could be used in photodynamic therapy. However, its poor solubility and hydrolytic instability limit its clinical use. The aim of the present study was to encapsulate Cur into solid lipid nanoparticles (SLNs) in order to improve its therapeutic activity. The Cur-loaded SLNs (Cur-SLNs) were prepared using an emulsification and low-temperature solidification method. The functions of Cur and Cur-SLNs were studied on the non-small cell lung cancer A549 cells for photodynamic therapy. The results revealed that Cur-SLNs induced ~2.27-fold toxicity higher than free Cur at a low concentration of 15 μM under light excitation, stocking more cell cycle at G2/M phase. Cur-SLNs could act as an efficient drug delivery system to increase the intracellular concentration of Cur and its accumulation in mitochondria; meanwhile, the hydrolytic stability of free Cur could be improved. Furthermore, Cur-SLNs exposed to 430 nm light could produce more reactive oxygen species to induce the disruption of mitochondrial membrane potential. Western blot analysis revealed that Cur-SLNs increased the expression of caspase-3, caspase-9 proteins and promoted the ratio of Bax/Bcl-2. Overall, the results from these studies demonstrated that the SLNs could enhance the phototoxic effects of Cur.
Vandita, Kakkar; Shashi, Bhushan; Santosh, Kumar Guru; Pal, Kaur Indu
Curcumin is reported to show potent in vitro anticancer effects in a surfeit of human cancer cell lines and majorly in the carcinogenesis of GIT, in animals. Its poor pharmacokinetics and stability limit its vivo clinical efficacy for the other systemic cancers. We recently reported on a 32-155 times enhancement in bioavailability of curcumin when incorporated into solid lipid nanoparticles (C-SLNs). Presently we report on a 54-85% reduction in IC 50 values with developed C-SLNs in comparison to free curcumin against a panel of human cancer cell lines (HL-60, A549, and PC3). Results demonstrate mechanisms similar to those claimed for free curcumin, including induction of cellular apoptosis by activation of caspases, release of cyctochrome c, loss of membrane potential, blockade of nuclear factor kappa B (NF-κB) activation, and upregulation of TNF-R for C-SLNs. However, the extent of cell death provided by C-SLNs in all these tests was significantly higher (p < 0.001). This may be attributed to the presentation of curcumin in a dispersible/soluble form which enhanced permeability across the cell surface. The display of significantly better in vitro anticancer effect coupled with high in vivo bioavailability points toward a great potential of using C-SLNs for cancer therapeutics.
Jiang, Shan; Zhu, Rongrong; He, Xiaolie; Wang, Jiao; Wang, Mei; Qian, Yechang; Wang, Shilong
Curcumin (Cur) is a promising photosensitizer that could be used in photodynamic therapy. However, its poor solubility and hydrolytic instability limit its clinical use. The aim of the present study was to encapsulate Cur into solid lipid nanoparticles (SLNs) in order to improve its therapeutic activity. The Cur-loaded SLNs (Cur-SLNs) were prepared using an emulsification and low-temperature solidification method. The functions of Cur and Cur-SLNs were studied on the non-small cell lung cancer A549 cells for photodynamic therapy. The results revealed that Cur-SLNs induced ~2.27-fold toxicity higher than free Cur at a low concentration of 15 μM under light excitation, stocking more cell cycle at G2/M phase. Cur-SLNs could act as an efficient drug delivery system to increase the intracellular concentration of Cur and its accumulation in mitochondria; meanwhile, the hydrolytic stability of free Cur could be improved. Furthermore, Cur-SLNs exposed to 430 nm light could produce more reactive oxygen species to induce the disruption of mitochondrial membrane potential. Western blot analysis revealed that Cur-SLNs increased the expression of caspase-3, caspase-9 proteins and promoted the ratio of Bax/Bcl-2. Overall, the results from these studies demonstrated that the SLNs could enhance the phototoxic effects of Cur. PMID:28053531
Arana, Lide; Salado, Clarisa; Vega, Sandra; Aizpurua-Olaizola, Oier; de la Arada, Igor; Suarez, Tatiana; Usobiaga, Aresatz; Arrondo, José Luis R; Alonso, Alicia; Goñi, Félix M; Alkorta, Itziar
Solid lipid nanoparticles (SLN) composed of long-chain fatty acids (palmitic acid, stearic acid or arachidic acid), Epikuron 200 (purified phosphatidylcholine), and bile salts (cholate, taurocholate or taurodeoxycholate) have been prepared by dilution of a microemulsion. A total of five different systems were prepared, and characterized by photon correlation spectroscopy, transmission electron microscopy, differential scanning calorimetry, and infrared spectroscopy. The SLN formulation showing optimal properties (lowest size and polydispersity index and highest zeta potential) was obtained with stearic acid and taurodeoxycholate as cosurfactant. This formulation was loaded with Calendula officinalis extract, a natural compound used on ophthalmic formulations given its anti-inflammatory, emollient, and wound repairing activity. Calendula-loaded SLN preparations were characterized in order to determine loading capacity and entrapment efficiency. In vitro cytotoxicity and wound healing efficacy of Calendula-loaded SLN compared to that of a free plant extract were evaluated on a conjunctival epithelium cell line WKD. Our results suggest that this SLN formulation is a safe and solvent-free Calendula extract delivery system which could provide a controlled therapeutic alternative for reducing disease-related symptoms and improving epithelium repair in ocular surface.
Zhang, Yong-Tai; Han, Meng-Qing; Shen, Li-Na; Zhao, Ji-Hui; Feng, Nian-Ping
In this study, solid lipid nanoparticles were formulated for transdermal delivery of aconitine to improve its safety and permeability. Aconitine-loaded solid lipid nanoparticles were formulated as an oil-in-water microemulsion. Drug encapsulation efficiencies for these formulations were higher than 85%, and correlated positively with levels of surfactant and oil matrix. The size of the solid lipid nanoparticles was increased with an increase of the oil matrix, and reduction of the surfactant levels. Compared with an ethanol tincture, all the tested solid lipid nanoparticle formulations achieved improved transdermal fluxes and drug deposition in skin in vitro. Real-time monitoring of drug distribution in rat dermis using in vivo microdialysis showed that aconitine concentration was markedly higher following application of solid lipid nanoparticles, compared to tincture, throughout the experimental period. A regional comparison of rat skin found that application of solid lipid nanoparticles to the scapular region resulted in higher AUC(0-t) and C(max), compared to those achieved with application to the abdomen or chest (p < 0.05). In contrast, the application to the chest resulted in the lowest AUC(0-t) and C(max). Together with findings of a structural study of the skin, these results indicated that the drug accumulated more readily in thicker skin regions, and to a lesser extent in well-perfused skin, because of drug transfer to capillaries. The superior transdermal permeability of aconitine-loaded solid lipid nanoparticles contributed to stronger anti-inflammatory and analgesic effects on mouse in vivo models of pain than the tincture (p < 0.05). In vitro and in vivo studies indicated that smaller particle sizes of solid lipid nanoparticles enhanced the transdermal permeability of aconitine, which can promote drug efficacy, reduce administration time, and improve medication safety.
Pizzol, Carine Dal; Filippin-Monteiro, Fabíola Branco; Restrepo, Jelver Alexander Sierra; Pittella, Frederico; Silva, Adny Henrique; Alves de Souza, Paula; Machado de Campos, Angela; Creczynski-Pasa, Tânia Beatriz
Nine types of solid lipid nanoparticle (SLN) formulations were produced using tripalmitin (TPM), glyceryl monostearate (GM) or stearic acid (SA), stabilized with lecithin S75 and polysorbate 80. Formulations were prepared presenting PI values within 0.25 to 0.30, and the physicochemical properties, stability upon storage and biocompatibility were evaluated. The average particle size ranged from 116 to 306 nm, with a negative surface charge around -11 mV. SLN presented good stability up to 60 days. The SLN manufactured using SA could not be measured by DLS due to the reflective feature of this formulation. However, TEM images revealed that SA nanoparticles presented square/rod shapes with an approximate size of 100 nm. Regarding biocompatibility aspects, SA nanoparticles showed toxicity in fibroblasts, causing cell death, and produced high hemolytic rates, indicating toxicity to red blood cells. This finding might be related to lipid type, as well as, the shape of the nanoparticles. No morphological alterations and hemolytic effects were observed in cells incubated with SLN containing TPM and GM. The SLN containing TPM and GM showed long-term stability, suggesting good shelf-life. The results indicate high toxicity of SLN prepared with SA, and strongly suggest that the components of the formulation should be analyzed in combination rather than separately to avoid misinterpretation of the results.
Soni, Maheshkumar P.; Shelkar, Nilakash; Gaikwad, Rajiv V.; Vanage, Geeta R.; Samad, Abdul; Devarajan, Padma V.
Background: Buparvaquone (BPQ), a hydroxynaphthoquinone derivative, has been investigated for the treatment of many infections and is recommended as the gold standard for the treatment of theileriosis. Theileriosis, an intramacrophage infection is localized mainly in reticuloendotheileial system (RES) organs. The present study investigates development of solid lipid nanoparticles (SLN) of BPQ for targeted delivery to the RES. Materials and Methods: BPQ SLN was prepared using melt method by adding a molten mixture into aqueous Lutrol F68 solution (80°C). Larger batches were prepared up to 6 g of BPQ with GMS: BPQ, 2:1. SLN of designed size were obtained using ultraturrax and high pressure homogenizer. A freeze and thaw study was used to optimize type and concentration of cryoprotectant with Sf: Mean particle size, Si: Initial particle size <1.3. Differential scanning calorimetry (DSC), powder X-ray diffraction (XRD) and scanning electron microscope (SEM) study was performed on optimized formulation. Formulation was investigated for in vitro serum stability, hemolysis and cell uptake study. Pharmacokinetic and biodistribution study was performed in Holtzman rat. Results: Based on solubility in lipid; glyceryl monostearate (GMS) was selected for preparation of BPQ SLN. Batches of BPQ SLN were optimized for average particle size and entrapment efficiency at <100 mg solid content. A combination of Solutol HS-15 and Lutrol F68 at 2% w/v and greater enabled the desired Sf/Si < 1.3. Differential scanning calorimetry and powder X-ray diffraction revealed decrease in crystallinity of BPQ in BPQ SLN while, scanning electron microscope revealed spherical morphology. BPQ SLN revealed good stability at 4°C and 25°C. Low hemolytic potential (<8%) and in vitro serum stability up to 5 h was observed. Cytotoxicity of SLN to the U937 cell was low. The macrophage cell line revealed high (52%) uptake of BPQ SLN in 1 h suggesting the potential to RES uptake. SLN revealed longer
Jang, Dong-Jin; Moon, Cheol; Oh, Euichaul
This study aimed to enhance the in vivo antitumor effects of camptothecin (CPT), a strong antitumor agent whose delivery is limited by poor aqueous solubility and instability of the active lactone form. CPT was loaded into sterically stabilized, solid lipid nanoparticles (CPT-SLNs) formulated for intravenous administration. The influence of preinjected blank SLNs on the tumor targeting, pharmacokinetics and antitumor activity of CPT-SLNs was investigated. The CPT-SLNs composed of trilaurin-based lipid matrix containing poloxamer188 and pegylated phospholipid as stabilizers were prepared by hot homogenization method and evaluated for in vitro characteristics and in vivo performance. The CPT-SLNs showed an in vitro long-term sustained release pattern and effectively protected the CPT lactone form from hydrolysis under physiological conditions. Notable tumor targeting and tumor growth inhibition were observed after intravenous administration of CPT-SLNs to mice with subcutaneous transplants of CT26 carcinoma cells. In pharmacokinetic studies in rats, CPT-SLNs markedly elevated plasma CPT level and prolonged blood circulation compared to free CPT. Nonetheless, high uptake of CPT-SLNs by reticuloendothelial system (RES)-rich tissues resulted in limited tumor targeting of CPT-SLNs and plasma CPT levels. Preinjection of blank SLNs before administration of CPT-SLNs to tumor-bearing mice substantially reduced the accumulation of CPT-SLNs in RES organs. This led to significantly enhanced tumor targeting, improved pharmacokinetic parameters and increased antitumor efficacy of CPT-SLNs. These results suggested that the in vivo antitumor effects of CPT-SLNs could be further enhanced by preinjection of blank SLNs. Therefore, CPT-SLNs with preinjected blank SLNs could be a potential approach for stable and effective CPT-based cancer therapy.
Khatak, Sunil; Dureja, Harish
The various approaches have been utilized in the treatment of a variety of diseases by applying drug delivery system such as polymeric nanoparticles, self-emulsifying delivery systems, liposomes, microemulsions and micellar solutions. Recently, solid lipid nanoparticles (SLNs), nanostructured lipid carriers (NLCs) and lipid-drug conjugates (LDCs) have been exploited as a carrier of lipophilic and hydrophilic/amphiphilic substances for invasive and non-invasive routes of delivery. SLNs are colloidal drug carrier system and are like nanoemulsion, however, the lipid content in SLNs is solid in nature. These novel type of lipid nanoparticles with solid matrix offers to develop new prototype therapeutics in drug delivery, which could be used for controlled release, drug targeting, gene therapy, physical and chemical stability and site-specific drug delivery and thereby attracted the research groups worldwide. This manuscript overviews the recent patents, advantages, formulation techniques, stability aspects and applications of SLNs.
Ikeuchi-Takahashi, Yuri; Ishihara, Chizuko; Onishi, Hiraku
In this study, solid lipid nanoparticle (SLN) suspensions were prepared using a base of hard fat with or without ethylcellulose (EC) and polyvinyl alcohols (PVA) and polysorbate (Tween) 60 surfactants. Commercially available PVAs vary in their degree of saponification and polymerization, and the appropriate PVAs to form SLNs from hard fat with or without EC were investigated. A relatively low-saponification-degree PVA was required to reproducibly form SLN suspensions without EC and relatively high-saponification-degree PVAs were suitable for SLNs with EC. The release of morin from SLNs with EC was more sustained than that from SLNs without EC. The maximum plasma concentration (Cmax) of SLNs with and without EC were almost the same, and both were higher than that of a morin suspension. The area under the curve for 0 to 360 min (AUC0-360) of SLNs with EC was increased compared with those of a morin suspension and SLNs without EC. The median diameter of SLNs with EC and a very low-saponification-degree PVA was decreased compared to other formulation, and morin release was more sustained for this formulation. SLNs with EC and a very low-saponification-degree PVA showed higher Cmax and AUC0-360 than SLNs with EC lacking a very low-saponification-degree PVA. The optimized SLNs with EC and a very low-saponification-degree PVA improved bioavailability via increased accessibility to the enterocyte surface by decreased particle size and increased permeation of SLN encapsulated morin through the intestinal membrane by sustained release properties.
Schoenitz, M; Joseph, S; Nitz, A; Bunjes, H; Scholl, S
The contribution describes the transfer from a batch to a micro-continuous process for the production of stable solid lipid nanoparticles as drug carrier systems. Solid lipid nanoparticles are commonly prepared batch-wise often resulting in poorly defined product qualities with regard to the polymorphic state of their lipid matrix. In order to obtain solid lipid nanoparticle dispersions that meet the requirements for an acceptable pharmaceutical product, the manufacture of reproducible product qualities preferably containing the stable crystal form of the respective matrix lipid is necessary. These requests are addressed by the continuous preparation process of solid lipid nanoparticles. A four step feasibility study for the standardized evaluation whether or not a colloidal lipid dispersion is suitable for continuous crystallization of the particles resulting in stable crystal forms is presented. The process is based on the continuous crystallization and subsequent thermal treatment of differently stabilized, tripalmitin-based nanoparticle formulations in microstructured devices. The successful production of the stable crystal form by means of a continuous process chain is shown for a dispersion stabilized with a blend of hydrogenated soybean lecithin and sodium glycocholate.
Uner, M; Wissing, S A; Yener, G; Müller, R H
The aim of this study was to improve the chemical stability of ascorbyl palmitate (AP) in a colloidal lipid carrier for its topical use. For this purpose, AP-loaded solid lipid nanoparticles (SLN), nanostructured lipid carriers (NLC) and for comparison, a nanoemulsion (NE) were prepared employing the high pressure homogenization technique and stored at room temperature (RT), 4 degrees C and 40 degrees C. During 3 months, physical stability of these formulations compared to placebo formulations which were prepared by the same production method, was studied including recrystallization behaviour of the lipid with differential scanning calorimetry (DSC), particle size distribution and storage stability with photon correlation spectroscopy (PCS) and laser diffractometry (LD). After evaluating data indicating excellent physical stability, AP-loaded SLN, NLC and NE were incorporated into a hydrogel by the same production method as the next step. Degradation of AP by HPLC and physical stability in the same manner were investigated at the same storage temperatures during 3 months. As a result, AP was found most stable in both the NLC and SLN stored at 4 degrees C (p > 0.05) indicating the importance of storage temperature. Nondegraded AP content in NLC, SLN and NE was found to be 71.1% +/- 1.4, 67.6% +/- 2.9 and 55.2% +/- 0.3 after 3 months, respectively. Highest degradation was observed with NE at all the storage temperatures indicating even importance of the carrier structure.
Hsu, Ming-Huang; Su, Yu-Chuan
This paper presents the development of magnetic lipid nanoparticles that could serve as controlled delivery vehicles for releasing encapsulated drugs in a desired manner. The nanoparticles are composed of multiple drugs in lipid matrices, which are solid at body temperature and melt around 45 degrees C to 55 degrees C. In addition, super-paramagnetic gamma-Fe2O3 particles with sizes ranging from 5 to 25 nm are surface modified and dispersed uniformly in the lipid nanoparticles. In the prototype demonstration, lipid nanoparticles with average sizes between 100 and 180 nm were fabricated by high-pressure homogenization at elevated temperatures. When exposed to an alternating magnetic field of 60 kA/m at 25 kHz, a solution containing 2 g/L encapsulated gamma-Fe2O3 particles showed a temperature increase from 37 degrees C to 50 degrees C in 20 min. Meanwhile, the dissipated heat melted the surrounding lipid matrices and resulted in an accelerated release of the encapsulated drugs. Within 20 min, approximately 35% of the encapsulated drug molecules were released from the lipid nanoparticles through diffusion. As such, the presented lipid nanoparticles enable a new scheme that combines magnetic control of heating and drug delivery, which could greatly enhance the performance of encapsulated drugs.
Weber, S; Zimmer, A; Pardeike, J
Drug delivery by inhalation is a noninvasive means of administration that has following advantages for local treatment for airway diseases: reaching the epithelium directly, circumventing first pass metabolism and avoiding systemic toxicity. Moreover, from the physiological point of view, the lung provides advantages for systemic delivery of drugs including its large surface area, a thin alveolar epithelium and extensive vasculature which allow rapid and effective drug absorption. Therefore, pulmonary application is considered frequently for both, the local and the systemic delivery of drugs. Lipid nanoparticles - Solid Lipid Nanoparticles and Nanostructured Lipid Carriers - are nanosized carrier systems in which solid particles consisting of a lipid matrix are stabilized by surfactants in an aqueous phase. Advantages of lipid nanoparticles for the pulmonary application are the possibility of a deep lung deposition as they can be incorporated into respirables carriers due to their small size, prolonged release and low toxicity. This paper will give an overview of the existing literature about lipid nanoparticles for pulmonary application. Moreover, it will provide the reader with some background information for pulmonary drug delivery, i.e., anatomy and physiology of the respiratory system, formulation requirements, application forms, clearance from the lung, pharmacological benefits and nanotoxicity.
Gönüllü, Ümit; Üner, Melike; Yener, Gülgün; Karaman, Ecem Fatma; Aydoğmuş, Zeynep
Solid lipid nanoparticles (SLN), nanostructured lipid carriers (NLC) and nanoemulsion (NE) of lornoxicam (LRX) were prepared for the treatment of painful and inflammatory conditions of the skin. Compritol® 888 ATO, Lanette® O and oleic acid were used as solid and liquid lipids. SLN, NLC and NE were found physically stable at various temperatures for 6 months. Case I diffusional drug release was detected as the dominant mechanism indicating Fickian drug diffusion from nanoparticles and nanoemulsion. The highest rate of drug penetration through rat skin was obtained with NE followed by NLC, SLN and a gel formulation. Nanoformulations significantly increased drug penetration through rat skin compared to the gel (p<0.05). Thus, SLN, NLC and NE of LRX can be suggested for relieving painful and inflammatory conditions of the skin.
Azhar Shekoufeh Bahari, Leila; Hamishehkar, Hamed
During the past decade, pharmaceutical science has seen rapid growth in interest for nanoscale materials. Solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) are popular research topics recently introduced as nano-scale drug carriers; they have shown numerous merits in drug delivery. Size is the most important index in a nanocarrier affecting its drug delivery efficiency. The influence of preparation conditions and type of lipidic components on the size of SLN and NLC in comparable states seems to be interesting for researchers who investigate these types of carriers. This review highlights the results of SLN and NLC particle size and size distribution comparisons. PMID:27478775
Kumar, Sacheen; Kaur, Jaspreet
Solid lipid nanoparticles are new paradigm of drug delivery system of water insoluble active pharmaceutical ingredient. Paliperidone, an antipsychotic used in treatment of schizophrenia is a water insoluble molecule with low bioavailability was studied. Macrogol glyceride surfactant, bile salt based surfactant and sodium dodecyl sulphate were used to stabilize the solid lipid as dispersed nanoparticles form by adsorbing on the surface of the nanoparticles. Anionic surfactants bile salt and sodium dodecyl sulphate were found to stabilize forming a monomolecular layer of surfactants on the surface of nanoparticles; whereas macrogol glyceride based surfactant have intrusion in the matrix of lipid nanoparticles. So intrusion of macrogol glyceride in matrix was observed by studying the change in size of nanoparticles with respect to temperature with the help of dynamic light scattering. In case of macrogol glyceride size decrease start form 50°C, for bile salt and sodium dodecyl sulphate size deacrease start at 60°C. So that structural disturbance of nanoparticles by the macrogol glyceride on the surface was found maximum as compared to anionic surfactant.
Natarajan, Jawahar; Baskaran, Mahendran; Humtsoe, Lireni C; Vadivelan, R; Justin, A
Olanzapine (OLZ) is a typical anti-psychotic drug, which is highly lipophilic in nature, belongs to Biopharmaceutical Classification System (BCS) class II category. Though OLZ is an effective agent in the treatment of Schizophrenia, but it exhibits poor bioavailability (57%) due to extensive first-pass metabolism resulted in high dose is required to achieve therapeutic concentration in brain. Emerging evidences are indicating that high dose administration of OLZ may cause Extrapyramidal symptoms (EPS) in the psychotic patients. Hence, the present study is designed to develop Olanzapine solid lipid (OLZ-SLNs) using minimal dose of OLZ thereby enhancing the brain efficacy as well as to reduce the side effects associated with OLZ. OLZ-SLNs have been prepared by "solvent diffusion method" using lipids, such as glyceryl monostearate (GMS), tripalmitin (TP), Tween 80, and Stearyl amine as positive charge inducer. The prepared OLZ-SLNs were subjected to particle size analysis, zeta potential, and poly dispersity index measurement by using Malvern Zetasizer. Pharmacokinetics assessments of OLZ-SLNs were carried in conscious male Wistar rats through intravenous administration. Results have shown that average particle size and zeta potential of SLNs of GMS and TP were ranged from 165.1 ± 2.2 to 110.5 ± 0.5 and 35.29 ± 1.2 and 66.50 ± 0.7 mV, respectively. Relative bioavailability of OLZ in the brain was increased up to 23-fold and clearance was decreased when OLZ-SLNs while administrated intravenously. The area under the curve (AUC) and mean residence time (MRT) of OLZ-SLNs in brain were higher than OLZ suspension. These results indicate that SLNs are a promising drug delivery for OLZ. It may be an effective tool to enhance the bioavailability of OLZ in the brain with less dose administration, which could reduce the EPS associated with OLZ.
Silva, Elton Luiz; Carneiro, Guilherme; De Araújo, Lidiane Advíncula; Trindade, Mariana de Jesus Vaz; Yoshida, Maria Irene; Oréfice, Rodrigo Lambert; Farias, Luis de Macêdo; De Carvalho, Maria Auxiliadora Roque; Dos Santos, Simone Gonçalves; Goulart, Gisele Assis Castro; Alves, Ricardo José; Ferreira, Lucas Antônio Miranda
Topical therapy is the first choice for the treatment of mild to moderate acne and all-trans retinoic acid is one of the most used drugs. The combination of retinoids and antimicrobials is an innovative approach for acne therapy. Recently, lauric acid, a saturated fatty acid, has shown strong antimicrobial activity against Propionibacterium acnes. However, topical application of retinoic acid is followed by high incidence of side-effects, including erythema and irritation. Solid lipid nanoparticles represent an alternative to overcome these side-effects. This work aims to develop solid lipid nanoparticles loaded with retinoic acid and lauric acid and evaluate their antibacterial activity. The influence of lipophilic stearylamine on the characteristics of solid lipid nanoparticles was investigated. Solid lipid nanoparticles were characterized for size, zeta potential, encapsulation efficiency, differential scanning calorimetry and X-ray diffraction. The in vitro inhibitory activity of retinoic acid-lauric acid-loaded solid lipid nanoparticles was evaluated against Propionibacterium acnes, Staphylococcus aureus and Staphylococcus epidermidis. High encapsulation efficiency was obtained at initial time (94 ± 7% and 100 ± 4% for retinoic acid and lauric acid, respectively) and it was demonstrated that lauric acid-loaded-solid lipid nanoparticles provided the incorporation of retinoic acid. However, the presence of stearylamine is necessary to ensure stability of encapsulation. Moreover, retinoic acid-lauric acid-loaded solid lipid nanoparticles showed growth inhibitory activity against Staphylococcus epidermidis, Propionibacterium acnes and Staphylococcus aureus, representing an interesting alternative for the topical therapy of acne vulgaris.
Gastaldi, Lucia; Battaglia, Luigi; Peira, Elena; Chirio, Daniela; Muntoni, Elisabetta; Solazzi, Ilaria; Gallarate, Marina; Dosio, Franco
Central nervous system disorders are already prevalent and steadily increasing among populations worldwide. However, most of the pharmaceuticals present on world markets are ineffective in treating cerebral diseases, because they cannot effectively cross the blood brain barrier (BBB). Solid lipid nanoparticles (SLN) are nanospheres made from biocompatible solid lipids, with unique advantages among drug carriers: they can be used as vehicles to cross the BBB. This review examines the main aspects surrounding brain delivery with SLN, and illustrates the principal mechanisms used to enhance brain uptake of the delivered drug.
Souto, E B; Anselmi, C; Centini, M; Müller, R H
Solid lipid nanoparticles (SLN) containing a novel potential sunscreen n-dodecyl-ferulate (ester of ferulic acid) were developed. The preparation and stability parameters of n-dodecyl-ferulate-loaded SLN have been investigated concerning particle size, surface electrical charge (zeta potential) and matrix crystallinity. The chemical stability of n-dodecyl-ferulate at high temperatures was also assessed by thermal gravimetry analysis. For the selection of the appropriated lipid matrix, chemically different lipids were melted with 4% (m/m) of active and lipid nanoparticles were prepared by the so-called high pressure homogenization technique. n-Dodecyl-ferulate-loaded SLN prepared with cetyl palmitate showed the lowest mean particle size and polydispersity index, as well as the highest physical stability during storage time of 21 days at 4, 20 and 40 degrees C. These colloidal dispersions containing the sunscreen also exhibited the common melting behaviour of aqueous SLN dispersions.
Doktorovova, Slavomira; Souto, Eliana B; Silva, Amélia M
Solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) were developed as alternative to other colloidal carriers. They were designed to overcome lipid nanoemulsions and liposomes in stability and ability to control the release of an encapsulated substance, and at the same time to be better tolerated than polymeric nanoparticles. Since the patenting of SLN discovery, large amount of data became available on the behaviour of these systems in vitro. SLN/NLC have many prerequisites to be a well tolerated carrier - the currently available data seem to confirm it, but there are also some contradictory results. In this review, we collected the available data from cytotoxicity, oxidative stress and hemocompatibility studies in vitro and analysed their outcomes. We also provide a summary of the available data in a form of reference table.
El-Salamouni, Noha S; Farid, Ragwa M; El-Kamel, Amal H; El-Gamal, Safaa S
Nanoparticulate delivery systems have recently been under consideration for topical ophthalmic drug delivery. Brimonidine base-loaded solid lipid nanoparticles and nanostructured lipid carrier formulations were prepared using glyceryl monostearate as solid lipid and were evaluated for their physical stability following sterilization by autoclaving at 121°C for 15min. The objective of this work was to evaluate the effect of autoclaving on the physical appearance, particle size, polydispersity index, zeta potential, entrapment efficiency and particle morphology of the prepared formulations, compared to non-autoclaved ones. Results showed that, autoclaving at 121°C for 15min allowed the production of physically stable formulations in nanometric range, below 500nm suitable for ophthalmic application. Moreover, the autoclaved samples appeared to be superior to non-autoclaved ones, due to their increased zeta potential values, indicating a better physical stability. As well as, increased amount of brimonidine base entrapped in the tested formulations.
Ngwuluka, Ndidi C; Kotak, Darsheen J; Devarajan, Padma V
Colorectal cancer is a global concern, and its treatment is fraught with non-selective effects including adverse side effects requiring hospital visits and palliative care. A relatively safe drug formulated in a bioavailability enhancing and targeting delivery platform will be of significance. Metformin-loaded solid lipid nanoparticles (SLN) were designed, optimized, and characterized for particle size, zeta potential, drug entrapment, structure, crystallinity, thermal behavior, morphology, and drug release. Optimized SLN were 195.01 ± 6.03 nm in size, -17.08 ± 0.95 mV with regard to surface charge, fibrous in shape, largely amorphous, and release of metformin was controlled. The optimized size, charge, and shape suggest the solid lipid nanoparticles will migrate and accumulate in the colon tumor preventing its proliferation and subsequently leading to tumor shrinkage and cell death.
Chabra, S; Ranjan, M; Bhandari, R; Kaur, T; Aggrawal, M; Puri, V; Mahajan, N; Kaur, IP; Puri, S; Sobti, RC
A rapid decline in self-renewability, viability and function, of isolated stem cells are major hurdles in developing cell based therapies. There has been an increasing interest towards identifying a support material for maintaining stem cell features of the isolated cells. Pioneering observations of the present paper, demonstrate functionally diverse potential of Solid Lipid Nanoparticles (SLNs) in deciding the fate & behavior of mouse mesenchymal stem cell. The evidences are provided to show the dual nature of the SLNs for being a scaffold for the stem cell attachment, to retain stemness, and as reagent for inducing stem cell differentiation. Scanning electron microscopic examinations together with expression analysis were used to conform to such observations. Results of the study thus suggest that Solid lipid nanoparticles can be used as a good support material when functionalized to achieve adhesive properties and as a molecular paradigm for studying the adipocytic differentiation. We envisage a new role of SLNs towards regulating stem cell character by orchestrating the structural alignment during preparation of Solid lipid nanoparticles PMID:24693174
Chauhan, Harsh; Mohapatra, Sarat; Munt, Daniel J; Chandratre, Shantanu; Dash, Alekha
Pure glyceryl mono-oleate (GMO) (lipid) and different batches of GMO commonly used for the preparation of GMO-chitosan nanoparticles were characterized by modulated differential scanning calorimetry (MDSC), cryo-microscopy, and cryo-X-ray powder diffraction techniques. GMO-chitosan nanoparticles containing poloxamer 407 as a stabilizer in the absence and presence of polymers as crystallization inhibitors were prepared by ultrasonication. The effect of polymers (polyvinyl pyrrolidone (PVP), Eudragits, hydroxyl propyl methyl cellulose (HPMC), polyethylene glycol (PEG)), surfactants (poloxamer), and oils (mineral oil and olive oil) on the crystallization of GMO was investigated. GMO showed an exothermic peak at around -10°C while cooling and another exothermic peak at around -12°C while heating. It was followed by two endothermic peaks between 15 and 30 C, indicative of GMO melting. The results are corroborated by cryo-microscopy and cryo-X-ray. Significant differences in exothermic and endothermic transition were observed between different grades of GMO and pure GMO. GMO-chitosan nanoparticles resulted in a significant increase in particle size after lyophilization. MDSC confirmed that nanoparticles showed similar exothermic crystallization behavior of lipid GMO. MDSC experiments showed that PVP inhibits GMO crystallization and addition of PVP showed no significant increase in particle size of solid lipid nanoparticle (SLN) during lyophilization. The research highlights the importance of extensive physical-chemical characterization for successful formulation of SLN.
Kushwaha, Anand Kumar; Vuddanda, Parameswara Rao; Karunanidhi, Priyanka; Singh, Sanjay Kumar; Singh, Sanjay
Raloxifene hydrochloride (RL-HCL) is an orally selective estrogen receptor modulator (SERM) with poor bioavailability of nearly 2% due to its poor aqueous solubility and extensive first pass metabolism. In order to improve the oral bioavailability of raloxifene, raloxifene loaded solid lipid nanoparticles (SLN) have been developed using Compritol 888 ATO as lipid carrier and Pluronic F68 as surfactant. Raloxifene loaded SLN were prepared by solvent emulsification/evaporation method, and different concentrations of surfactant, and homogenization speed were taken as process variables for optimization. SLN were characterized for particle size, zeta potential, entrapment efficiency, surface morphology, and crystallinity of lipid and drug. In vitro drug release studies were performed in phosphate buffer of pH 6.8 using dialysis bag diffusion technique. Particle sizes of all the formulations were in the range of 250 to 1406 nm, and the entrapment efficiency ranges from 55 to 66%. FTIR and DSC studies indicated no interaction between drug and lipid, and the XRD spectrum showed that RL-HCL is in amorphous form in the formulation. In vitro release profiles were biphasic in nature and followed Higuchi model of release kinetics. Pharmacokinetics of raloxifene loaded solid lipid nanoparticles after oral administration to Wistar rats was studied. Bioavailability of RL-HCL loaded SLN was nearly five times than that of pure RL-HCL.
Elnaggar, Yosra SR; El-Massik, Magda A; Abdallah, Ossama Y
Although sildenafil citrate (SC) is used extensively for erectile dysfunction, oral delivery of SC encounters many obstacles. Furthermore, the physicochemical characteristics of this amphoteric drug are challenging for delivery system formulation and transdermal permeation. This article concerns the assessment of the potential of nanomedicine for improving SC delivery and transdermal permeation. SC-loaded nanostructured lipid carriers (NLCs) and solid lipid nanoparticles (SLNs) were fabricated using a modified high-shear homogenization technique. Nanoparticle optimization steps included particle size analysis, entrapment efficiency (EE) determination, freeze-drying and reconstitution, differential scanning calorimetry, in vitro release, stability study and high-performance liquid chromatography analysis. Transdermal permeation of the nanocarriers compared with SC suspension across human skin was assessed using a modified Franz diffusion cell assembly. Results revealed that SLNs and NLCs could be optimized in the nanometric range (180 and 100 nm, respectively) with excellent EE (96.7% and 97.5%, respectively). Nanoparticles have significantly enhanced in vitro release and transdermal permeation of SC compared with its suspensions. Furthermore, transdermal permeation of SC exhibited higher initial release from both SLN and NLC formulations followed by controlled release, with promising implications for faster onset and longer drug duration. Nanomedicines prepared exhibited excellent physical stability for the study period. Solid nanoparticles optimized in this study successfully improved SC characteristics, paving the way for an efficient topical Viagra® product. PMID:22238508
Dikmen, Gokhan; Guney, Gamze; Genc, Lutfi
Many anticancer drugs that are currently used in cancer treatment are natural products or their analogues by structural modification. Caffeic acid (3, 4-dihydroxycinnamic acid; CA) is classified as hydroxycinnamic acid and has a variety of potential pharmacological effects, including antioxidant, immunomodulatory and anti-inflammatory activities. As a drug carrier, solid lipid nanoparticles (SLNs) introduced to improve stability, provide controlled drug release, avoid organic solvents and are obtained in small sizes. In this study, we developed solid lipid nanoparticles incorporating with caffeic acid using hot homogenization method. Caffeic acid loaded solid lipid nanoparticles were characterized regarding particle size, zeta potential, drug entrapment efficiency, drug release, scanning electron microscopy (SEM) and FT-IR. The effects of caffeic acid loaded solid lipid nanoparticles on MCF-7 cells were determined by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-dimethyl tetrazolium bromide (MTT) test and Annexin V-PI analysis. As a result, solid lipid nanoparticles could potentially be used for the delivery of caffeic acid and solid lipid nanoparticles formulation enhanced the effects of caffeic acid on MCF-7 cells. Some relevant patents are also referred in this article.
Spada, Gianpiera; Gavini, Elisabetta; Cossu, Massimo; Rassu, Giovanna; Giunchedi, Paolo
New solid lipid nanoparticles (SLN), composed of Compritol ATO888 (C) and hydroxypropyl-β-cyclodextrin (HP), were developed in order to study a new colon-specific formulation for diclofenac sodium (D) delivery. The prepared batches differ from each other by the molecular ratio between HP and D and by the composition of the matrix. Nanoparticles composed of an exclusively lipid matrix and nanoparticles with an oligomeric and lipid matrix were compared in order to establish the effect of both components on the drug delivery tests performed. The SLN preparation method was based on the oil/water hot homogenization process. Emulsions produced were cooled at room temperature and lyophilized in order to obtain dried nanoparticles; possible damage to nanoparticle shape and size was avoided by the addition of cryoprotectants to the aqueous dispersion of nanoparticles before exsiccation. An in vitro toxicity study was performed using CaCo2 cells to establish the safety of the prepared SLN. Data obtained showed that production method studied guarantees emulsions composed of nanosized drops which can be dried by lyophilization into SLN with a size range of 300-600 nm. In vitro and ex vivo tests demonstrated that dried SLN can be considered as colon delivery systems; however, the matrix composition as well as the presence of cryoprotectant on their surface influences the release and permeation rate of D. The in vitro toxicity studies indicated that the SLN are well tolerated.
Müller, R H; Runge, S A; Ravelli, V; Thünemann, A F; Mehnert, W; Souto, E B
Solid lipid nanoparticles (SLN) were produced loaded with cyclosporine A in order to develop an improved oral formulation. In this study, the particles were characterized with regard to the structure of the lipid particle matrix, being a determining factor for mode of drug incorporation and drug release. Differential scanning calorimetry (DSC) and wide-angle X-ray scattering (WAXS) measurements were employed for the analysis of the polymorphic modifications and mode of drug incorporation. Particles were produced using Imwitor 900 as lipid matrix (the suspension consisted of 10% particles, 8% Imwitor 900, 2% cyclosporine A), 2.5% Tagat S, 0.5% sodium cholate and 87% water. DSC and WAXS were used to analyse bulk lipid, bulk drug, drug incorporated in the bulk and unloaded and drug-loaded SLN dispersions. The processing of the bulk lipid into nanoparticles was accompanied by a polymorphic transformation from the beta to the alpha-modification. After production, the drug-free SLN dispersions converted back to beta-modification, while the drug-loaded SLN stayed primarily in alpha-modification. After incorporation of cyclosporine A into SLN, the peptide lost its crystalline character. Based on WAXS data, it could be concluded that cyclosporine is molecularly dispersed in between the fatty acid chains of the liquid-crystalline alpha-modification fraction of the loaded SLN.
Salminen, Hanna; Gömmel, Christina; Leuenberger, Bruno H; Weiss, Jochen
We investigated the influence of physicochemical properties of encapsulated functional lipids--vitamin A, β-carotene and ω-3 fish oil--on the structural arrangement of solid lipid nanoparticles (SLN). The relationship between the crystal structure and chemical stability of the incorporated bioactive lipids was evaluated with different emulsifier compositions of a saponin-rich, food-grade Quillaja extract alone or combined with high-melting or low-melting lecithins. The major factors influencing the structural arrangement and chemical stability of functional lipids in solid lipid dispersions were their solubility in the aqueous phase and their crystallization temperature in relation to that of the carrier lipid. The results showed that the stabilization of the α-subcell crystals in the lattice of the carrier lipid is a key parameter for forming stable solid lipid dispersions. This study contributes to a better understanding of SLN as a function of the bioactive lipid.
Becker Peres, Luana; Becker Peres, Laize; de Araújo, Pedro Henrique Hermes; Sayer, Claudia
Encapsulation of hydrophilic compounds for drug delivery systems with high loading efficiency is not easily feasible and remains a challenge, mainly due to the leaking of the drug to the outer aqueous phase during nanoparticle production. Usually, encapsulation of hydrophilic drugs is achieved by using double emulsion or inverse miniemulsion systems that often require the use of organic solvents, which may generate toxicological issues arising from solvent residues. Herein, we present the preparation of solid lipid nanoparticles loaded with a hydrophilic compound by a novel organic solvent free double emulsion/melt dispersion technique. The main objective of this study was to investigate the influence of important process and formulation variables, such as lipid composition, surfactant type, sonication parameters and lipid solidification conditions over physicochemical characteristics of SLN dispersion. Particle size and dispersity, as well as dispersion stability were used as responses. SLN dispersions with average size ranging from 277 to 550 nm were obtained, showing stability for over 60 days at 4 °C depending on the chosen emulsifying system. Entrapment efficiency of fluorescent dyes used as model markers was assessed by fluorescence microscopy and UV-vis spectrophotometry and results suggest that the obtained lipid based nanoparticles could be potentially applied as a delivery system of water soluble drugs.
Esmaeili, Maryam; Aghajani, Mahdi; Abbasalipourkabir, Roghayeh; Amani, Amir
Advantages of lipid nanoparticles for pulmonary applications are possibility of deep lung deposition with prolonged release and low toxicity. This study aimed to evaluate the effects of formulation and processing parameters on particle size of prepared SLNs. Budesonide-loaded solid lipid nanoparticles (BUD-SLNs) were prepared with different values of drug content, ultrasonication amplitude, and homogenization time and the data were modeled using artificial neural networks (ANNs). Optimal conditions for fabrication of small-sized particles of 170-200 nm were found to be low drug content with high-amplitude and high-homogenization time. In vitro aerosolization performance of BUD-SLNs was then compared to that of commercial budesonide which indicated enhancement in fine particle fraction value.
Hosny, Khaled Mohamed; Banjar, Zainy Mohammed; Hariri, Amani H; Hassan, Ali Habiballah
According to the World Health Organization, 46% of the world's children suffer from anemia, which is usually treated with iron supplements such as ferrous sulfate. The aim of this study was to prepare iron as solid lipid nanoparticles, in order to find an innovative way for alleviating the disadvantages associated with commercially available tablets. These limitations include adverse effects on the digestive system resulting in constipation and blood in the stool. The second drawback is the high variability in the absorption of iron and thus in its bioavailability. Iron solid lipid nanoparticles (Fe-SLNs) were prepared by hot homogenization/ultrasonication. Solubility of ferrous sulfate in different solid lipids was measured, and effects of process variables such as the surfactant type and concentration, homogenization and ultrasonication times, and charge-inducing agent on the particle size, zeta potential, and encapsulation efficiency were determined. Furthermore, in vitro drug release and in vivo pharmacokinetics were studied in rabbits. Results indicated that Fe-SLNs consisted of 3% Compritol 888 ATO, 1% Lecithin, 3% Poloxamer 188, and 0.2% dicetylphosphate, with an average particle size of 25 nm with 92.3% entrapment efficiency. In vivo pharmacokinetic study revealed more than fourfold enhanced bioavailability. In conclusion, Fe-SLNs could be a promising carrier for iron with enhanced oral bioavailability.
Hosny, Khaled Mohamed; Banjar, Zainy Mohammed; Hariri, Amani H; Hassan, Ali Habiballah
According to the World Health Organization, 46% of the world’s children suffer from anemia, which is usually treated with iron supplements such as ferrous sulfate. The aim of this study was to prepare iron as solid lipid nanoparticles, in order to find an innovative way for alleviating the disadvantages associated with commercially available tablets. These limitations include adverse effects on the digestive system resulting in constipation and blood in the stool. The second drawback is the high variability in the absorption of iron and thus in its bioavailability. Iron solid lipid nanoparticles (Fe-SLNs) were prepared by hot homogenization/ultrasonication. Solubility of ferrous sulfate in different solid lipids was measured, and effects of process variables such as the surfactant type and concentration, homogenization and ultrasonication times, and charge-inducing agent on the particle size, zeta potential, and encapsulation efficiency were determined. Furthermore, in vitro drug release and in vivo pharmacokinetics were studied in rabbits. Results indicated that Fe-SLNs consisted of 3% Compritol 888 ATO, 1% Lecithin, 3% Poloxamer 188, and 0.2% dicetylphosphate, with an average particle size of 25 nm with 92.3% entrapment efficiency. In vivo pharmacokinetic study revealed more than fourfold enhanced bioavailability. In conclusion, Fe-SLNs could be a promising carrier for iron with enhanced oral bioavailability. PMID:25609917
Bhushan, Shashi; Kakkar, Vandita; Pal, Harish Chandra; Guru, Santosh Kumar; Kumar, Ajay; Mondhe, D M; Sharma, P R; Taneja, Subhash Chandra; Kaur, Indu Pal; Singh, Jaswant; Saxena, A K
A pentacyclic triterpenediol (TPD) from Boswellia serrata has significant cytotoxic and apoptotic potential in a large number of human cancer cell lines. To enhance its anticancer potential, it was successfully formulated into solid lipid nanoparticles (SLNs) by the microemulsion method with 75% drug entrapment efficiency. SEM and TEM studies indicated that TPD-SLNs were regular, solid, and spherical particles in the range of 100-200 nm, and the system indicated that they were more or less stable upon storing up to six months. TPD loaded SLNs showed significantly higher cytotoxic/antitumor potential than the parent drug. TPD-SLNs have 40-60% higher cytotoxic and apoptotic potential than the parent drug in terms of IC(50), extent of apoptosis, DNA damage, and expression of pro-apoptotic proteins like TNF-R1, cytochrome-c, and PARP cleavage in HL-60 cells. Moreover, blank SLNs did not have any cytotoxic effect on the cancer as well as in normal mouse peritoneal macrophages. The in vivo antitumor potential of TPD-SLNs was significantly higher than that of TPD alone in Sarcoma-180 solid tumor bearing mice. Therefore, SLNs of TPD successfully increased the apoptotic and anticancer potential of TPD at comparable doses (both in vitro and in vivo). This work provides new insight into improvising the therapeutic efficacy of TPD by adopting novel delivery strategies such as solid lipid nanoparticles.
Kashanian, Soheila; Rostami, Elham
In this study, poly ethylene glycol 100 stearate (PEG 100-S) was used to prepare coated solid lipid nanoparticles with loading levothyroxine sodium (levo-loaded PEG 100-S-coated SLNs) by microemulsification technique. Evaluation of the release kinetic of prepared colloidal carriers was conducted. The particle size and zeta potential of levo-loaded PEG 100-S-coated SLNs have been measured to be 187.5 nm and -23.0 mV, respectively, using photon correlation spectroscopy (PCS). Drug entrapment efficiency (EE) was calculated to be 99 %. Differential scanning calorimetry indicated that the majority of drug loaded in PEG 100-S-coated SLNs were in amorphous state which could be considered desirable for drug delivery. The purpose of this study was to develop a new nanoparticle system, consisting lipid nanoparticles coated with PEG 100-S. The modification procedure led to a reduction in the zeta potential values, varying from -40.0 to -23.0 mV for the uncoated and PEG-coated SLNs, respectively. Stability results of the nanoparticles in gastric and intestinal media show that the low pH of the gastric medium is responsible for the critical aggregation and degradation of the uncoated lipid nanoparticles. PEG 100-S-coated SLNs were more stable due to their polymer coating layer which prevented aggregation of SLNs. Consequently, it is possible that the PEG surrounds the particles reducing the attachment of enzymes and further degradation of the triglyceride cores. Shape and surface morphology of particles were determined by transition electron microscopy and scanning electron microscopy that revealed spherical shape of nanoparticles. In vitro drug release of PEG 100-S-coated SLNs was characterized using diffusion cell which showed a controlled release for drug.
Hazzah, Heba A; Farid, Ragwa M; Nasra, Maha M A; El-Massik, Magda A; Abdallah, Ossama Y
This study aimed to prepare and evaluate mucoadhesive sponges as dosage forms for delivering solid lipid nanoparticles. For this purpose curcumin (Cur) was formulated as solid nanoparticles (SLN) using Gelucire 50/13, and polaxomer 407. The prepared CurSLN dispersion was thickened with different mucoadhesive polymers. Different concentrations of glycerol, and mannitol of range (0.25-20%), and (0-1%), respectively were also examined. The formed gel was poured into oblong molds and freeze dried to form mucoadhesive sponge to be applied to the buccal mucosa. The prepared sponges were evaluated for their, in-vivo residence time, in-vitro and in-vivo drug release, and hydration capacity. Surface morphology for the different sponges were examined using SEM. TEM was also carried out for sponge fragments previously dispersed into water. Infrared spectroscopy was conducted to investigate interaction between used ingredients. The results showed that the CurSLN loaded HPMC, and Polycarbophil sponges showed 4, and 15 h in-vivo residence time, respectively, providing a considerable amount of curcumin into saliva. The incorporation of glycerol and mannitol at concentration of 1% provided elegant and flexible sponges. The SEM showed that the deposition of CurSLN differed according to the type of polymer used. TEM confirmed the integrity of liberated CurSLN from sponges. IR spectra showed an interaction between HPMC and poloxamer 407, which affected its behavior as a gelling agent. The obtained results provide an efficient approach for delivering solid lipid nanoparticles in a solid dosage form keeping the nanoparticle characters and integrity.
Dasgupta, Sandipan; Ghosh, Surajit K; Ray, Subhabrata; Mazumder, Bhaskar
Solid lipid nanoparticles (SLN) are very potential formulations for topical delivery of anti-inflammatory and anti-arthritic drugs. The solid state of the lipid particles enable efficient drug encapsulation and controlled drug release. In the present study, the evaluation of different formulation parameters based on variation of concentration of lipid and cosurfactant was studied. The SLN gel formulations of the dispersions were compared to the SLN dispersions and with the marketed gel of aceclofenac. The SLNs were prepared by high speed homogenization and ultra-sonication method with fixed amount of aceclofenac (10%) and pluronic F68 (1.5%). The particle size, zeta potential and span of developed formulations was found to be within the range of 123 nm to 323 nm, -12.4 to -18.5 and 0.42 to 0.86 respectively as the lipid concentration was increased from 7.5% to 40%. The highest entrapment efficiency was found to be 75% with the formulation having lipid concentration of 30% and 0.85% of phospholipon 90G. Permeation rate and controlled release property of xanthan gum loaded SLN gel formulations and SLN dispersion was studied through excised pig skin for 24hr. The drug release of SLN gel formulations was better controlled as compare to SLN dispersions. In vivo anti-inflammatory study showed that action of aceclofenac was enhanced for SLN dispersion and gel formulations. The results indicated the superiority of SLN based formulations for topical delivery of aceclofenac.
The objective of this research was to formulate ciprofloxacin (CIP) in solid lipid nanoparticles (SLNs) in an attempt to develop a controlled drug delivery system. An ultrasonic melt-emulsification method was used for preparing CIP-loaded SLNs. Key findings included that SLNs were successfully produced with average particle sizes ranging from 165 to 320 nm and polydispersity index in the range of 0.18–0.33. High entrapment efficiency values were reported in all formulations. The atomic force scanning microscopic images showed spherical shape with the size range closer to those found by the particle size analyzer. CIP release exhibited controlled-release behavior with various lipids. Ciprofloxacin solid lipid nanoparticles formula containing stearic acid (CIPSTE) displayed the strongest burst effect and the most rapid release rate. The release data revealed a better fit to the Higuchi diffusion model. After storing the CIPSTE formula at room temperature for 120 days, no significant difference in particle size and zeta potential was found. CIP-loaded SLNs exhibited superior antibacterial activity. Incorporation of CIP into SLNs leads to controlled release and a superior antibacterial effect of CIP. PMID:28194408
Urbán-Morlán, Zaida; Ganem-Rondero, Adriana; Melgoza-Contreras, Luz María; Escobar-Chávez, José Juan; Nava-Arzaluz, María Guadalupe; Quintanar-Guerrero, David
Solid lipid nanoparticles (SLNs) have been used for carrying different therapeutic agents because they improve absorption and bioavailability. The aim of the study was to prepare lipidic nanoparticles containing cyclosporine (CyA) by the emulsification-diffusion method and to study their physicochemical stability. Glyceryl behenate (Compritol® ATO 888) and lauroyl macrogolglycerides (Gelucire® 44/14) were used as carrier materials. Nanoparticles with good stability were obtained with Gelucire®, while it was difficult to obtain stable systems with Compritol®. Systems with Gelucire® were characterized by particle size, Z-potential, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), entrapment efficiency and in vitro release. Particle size and Z-potential were evaluated for at least three months. With a high CyA content (≥60 mg) in Gelucire® SLNs, variations in size were greater and particle size also increased over time in all batches; this effect may have been caused by a probable expulsion of the drug due to the lipid’s partial rearrangement. While the Z-potential decreased 10 mV after three months, this effect may be explained by the superficial properties of the drug that make the molecules to be preferably oriented at the solid-liquid interface, causing a change in the net charge of the particle. SEM confirmed size and shape of the nanoparticles. DSC studies evidenced that CyA affects the lipid structure by a mechanism still unknown. The entrapment efficiency was higher than 92%, and CyA release from SLNs was relatively fast (99.60% in 45 min). PMID:20856836
Song, Aihua; Zhang, Xiaoshu; Li, Yanting; Mao, Xinjuan; Han, Fei
The aim of this study is to evaluate the effect of liquid-to-solid lipid ratio on properties of flurbiprofen-loaded solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs), and to clarify the superiority of NLCs over SLNs for transdermal administration. Particle size, zeta potential, drug encapsulation efficiency, in vitro occlusion factor, differential scanning calorimetry, X-ray diffractometry, in vitro percutaneous permeation profile, and stability of SLNs and NLCs were compared. Particle size, zeta potential, drug encapsulation efficiency, in vitro occlusion factor, and in vitro percutaneous permeation amount of the developed NLCs were all <200 nm, < -20 mV, >78%, >35, and >240 μg/cm(2), respectively, however, for SLNs were 280 nm, -29.11 mV, 63.2%, 32.54, and 225.9 μg/cm(2), respectively. After 3 months storage at 4 °C and 25 °C, almost no significant differences between the evaluated parameters of NLCs were observed. However, for SLNs, particle size was increased to higher than 300 nm (4 °C and 25 °C), drug encapsulation efficiency was decreased to 51.2 (25 °C), in vitro occlusion factor was also decreased to lower than 25 (4 °C and 25 °C), and the cumulative amount was decreased to 148.9 μg/cm(2) (25 °C) and 184.4 μg/cm(2) (4 °C), respectively. And DSC and XRD studies indicated that not only the crystalline peaks of the encapsulated flurbiprofen disappeared but also obvious difference between samples and bulk Compritol® ATO 888 was seen. It could be concluded that liquid-to-solid lipid ratio has significant impact on the properties of SLNs and NLCs, and NLCs showed better stability than SLNs. Therefore, NLCs might be a better option than SLNs for transdermal administration.
Barbosa, R. M.; da Silva, C. M. G.; Bella, T. S.; de Araújo, D. R.; Marcato, P. D.; Durán, N.; de Paula, E.
Dibucaine (DBC) is powerful long-lasting local anesthetic, but it is also considered fairly toxic to the CNS. Solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) have attracted attention as carriers for drug delivery. The aim of this study was to develop and to evaluate the cytotoxic activity of DBC-loaded SLN and NLC against 3T3 fibroblast and HaCat keratinocyte cells. The SLN and NLC had myristyl myristate and Liponate®GC as their lipid matrices, respectively, plus a surfactant. SLN and NLC were characterized in terms in their diameter, size distribution, surface charge and DBC encapsulation efficiency. The particle size of SLN and NLC were around 234.33 and 166.62 nm, respectively. The polydispersity index was kept below 0.2 for both nanomaterials. Negative surface charges were observed for both nanoparticles, which decreased in the presence of the anesthetic. Encapsulation efficiency reached 76% and 90%, respectively, in SLN and NLC. DBC alone was found to be toxic to 3T3 and HaCat cells in culture. However, NLC and SLN loaded DBC decreased its intrinsic cytotoxic effect against 3T3 and HaCat cells. In conclusion, encapsulation of DBC in SLN and NLC decreased the in vitro toxicity of the local anesthetic, indicating the potential of these nanocarriers for clinical applications.
Guo, Dawei; Dou, Dandan; Li, Xinyu; Zhang, Qian; Bhutto, Zohaib Ahmed; Wang, Liping
To avoid potential systematical toxicity, solid lipid nanoparticles (SLNs) were prepared as a vehicle for transdermal delivery of ivermectin (IVM) using hot homogenisation followed by ultrasonic method. The as-prepared SLNs were approximately spherical shape with good stability. IVM was encapsulated in amorphous form within SLNs and displayed prolonged release from SLNs without burst release due to high encapsulation efficiency (EE). The cumulative permeation of IVM across excised rat skin from SLNs was significantly increased compared to the ivermection suspension. These results indicated that the proposed SLNs can be considered as an efficient carrier for dermal delivery of IVM to effectively treat scabies.
Ezzati Nazhad Dolatabadi, Jafar; Valizadeh, Hadi; Hamishehkar, Hamed
In recent years, nanomaterials have been widely applied as advanced drug and gene delivery nanosystems. Among them, solid lipid nanoparticles (SLNs) have attracted great attention as colloidal drug delivery systems for incorporating hydrophilic or lipophilic drugs and various macromolecules as well as proteins and nucleic acids. Therefore, SLNs offer great promise for controlled and site specific drug and gene delivery. This article includes general information about SLN structures and properties, production procedures, characterization. In addition, recent progress on development of drug and gene delivery systems using SLNs was reviewed. PMID:26236652
Helgason, T; Awad, T S; Kristbergsson, K; McClements, D J; Weiss, J
The effect of surfactant surface coverage on formation and stability of Tween 20 stabilized tripalmitin solid lipid nanoparticles (SLN) was investigated. A lipid phase (10% w/w tripalmitin) and an aqueous phase (2% w/w Tween 20, 10 mM phosphate buffer, pH 7) were heated to 75 degrees C and then homogenized using a microfluidizer. The resulting oil-in-water emulsion was kept at a temperature (37 degrees C) above the crystallization temperature of the tripalmitin to prevent solidification of emulsion droplets, and additional surfactant at various concentrations (0-5% w/w Tween 20) was added. Droplets were then cooled to 5 degrees C to initiate crystallization and stored at 20 degrees C for 24 h. Particle size and/or aggregation were examined visually and by light scattering, and crystallization behavior was examined by differential scanning calorimetry (DSC). Excess Tween 20 concentration remaining in the aqueous phase was measured by surface tensiometry. Emulsion droplets after homogenization had a mean particle diameter of 134.1+/-2.0 nm and a polydispersity index of 0.08+/-0.01. After cooling to 5 degrees C at low Tween 20 concentrations, SLN dispersions rapidly gelled due to aggregation of particles driven by hydrophobic attraction between insufficiently covered lipid crystal surfaces. Upon addition of 1-5% w/w Tween 20, SLN dispersions became increasingly stable. At low added Tween 20 concentration (<1% w/w) the SLN formed gels but only increased slightly at higher surfactant concentrations (>1% w/w). The Tween 20 concentration in the aqueous phase decreased after tripalmitin crystallization suggesting additional surfactant adsorption onto solid surfaces. At higher Tween 20 concentrations, SLN had increasingly complex crystal structures as evidenced by the appearance of additional thermal transition peaks in the DSC. The results suggest that surfactant coverage at the interface may influence crystal structure and stability of solid lipid nanoparticles via
Campos, Estefânia Vangelie Ramos; Oliveira, Jhones Luiz de; da Silva, Camila Morais Gonçalves; Pascoli, Mônica; Pasquoto, Tatiane; Lima, Renata; Abhilash, P. C.; Fernandes Fraceto, Leonardo
Carbendazim (MBC) (methyl-2-benzimidazole carbamate) and tebuconazole (TBZ) ((RS)-1-(4-chlorophenyl)-4,4-dimethyl-3-(1H-1,2,4-triazol-1-ylmethyl)pentan-3-ol) are widely used in agriculture for the prevention and control of fungal diseases. Solid lipid nanoparticles and polymeric nanocapsules are carrier systems that offer advantages including changes in the release profiles of bioactive compounds and their transfer to the site of action, reduced losses due to leaching or degradation, and decreased toxicity in the environment and humans. The objective of this study was to prepare these two types of nanoparticle as carrier systems for a combination of TBZ and MBC, and then investigate the release profiles of the fungicides as well as the stabilities and cytotoxicities of the formulations. Both nanoparticle systems presented high association efficiency (>99%), indicating good interaction between the fungicides and the nanoparticles. The release profiles of MBC and TBZ were modified when the compounds were loaded in the nanoparticles, and cytotoxicity assays showed that encapsulation of the fungicides decreased their toxicity. These fungicide systems offer new options for the treatment and prevention of fungal diseases in plants. PMID:26346969
Campos, Estefânia Vangelie Ramos; Oliveira, Jhones Luiz De; da Silva, Camila Morais Gonçalves; Pascoli, Mônica; Pasquoto, Tatiane; Lima, Renata; Abhilash, P. C.; Fernandes Fraceto, Leonardo
Carbendazim (MBC) (methyl-2-benzimidazole carbamate) and tebuconazole (TBZ) ((RS)-1-(4-chlorophenyl)-4,4-dimethyl-3-(1H-1,2,4-triazol-1-ylmethyl)pentan-3-ol) are widely used in agriculture for the prevention and control of fungal diseases. Solid lipid nanoparticles and polymeric nanocapsules are carrier systems that offer advantages including changes in the release profiles of bioactive compounds and their transfer to the site of action, reduced losses due to leaching or degradation, and decreased toxicity in the environment and humans. The objective of this study was to prepare these two types of nanoparticle as carrier systems for a combination of TBZ and MBC, and then investigate the release profiles of the fungicides as well as the stabilities and cytotoxicities of the formulations. Both nanoparticle systems presented high association efficiency (>99%), indicating good interaction between the fungicides and the nanoparticles. The release profiles of MBC and TBZ were modified when the compounds were loaded in the nanoparticles, and cytotoxicity assays showed that encapsulation of the fungicides decreased their toxicity. These fungicide systems offer new options for the treatment and prevention of fungal diseases in plants.
Campos, Estefânia Vangelie Ramos; de Oliveira, Jhones Luiz; da Silva, Camila Morais Gonçalves; Pascoli, Mônica; Pasquoto, Tatiane; Lima, Renata; Abhilash, P C; Fraceto, Leonardo Fernandes
Carbendazim (MBC) (methyl-2-benzimidazole carbamate) and tebuconazole (TBZ) ((RS)-1-(4-chlorophenyl)-4,4-dimethyl-3-(1H-1,2,4-triazol-1-ylmethyl)pentan-3-ol) are widely used in agriculture for the prevention and control of fungal diseases. Solid lipid nanoparticles and polymeric nanocapsules are carrier systems that offer advantages including changes in the release profiles of bioactive compounds and their transfer to the site of action, reduced losses due to leaching or degradation, and decreased toxicity in the environment and humans. The objective of this study was to prepare these two types of nanoparticle as carrier systems for a combination of TBZ and MBC, and then investigate the release profiles of the fungicides as well as the stabilities and cytotoxicities of the formulations. Both nanoparticle systems presented high association efficiency (>99%), indicating good interaction between the fungicides and the nanoparticles. The release profiles of MBC and TBZ were modified when the compounds were loaded in the nanoparticles, and cytotoxicity assays showed that encapsulation of the fungicides decreased their toxicity. These fungicide systems offer new options for the treatment and prevention of fungal diseases in plants.
Wang, Ting; Chen, Xiaojin; Lu, Mengmeng; Li, Xihe; Zhou, WenZhong
A florfenicol-loaded solid lipid nanoparticle (FFC-SLN) suspension was prepared by hot homogenisation and ultrasonic technique. The suspension was characterised for its release profile, stability, toxicity, and the physicochemical properties of the nanoparticles. Antibacterial activity of the suspension was evaluated in vitro and in vivo. The results showed that the mean diameter, polydispersity index and zeta potential of the nanoparticles were 253 ± 3 nm, 0.409 ± 0.022 and 47.5 ± 0.21 mV, respectively. In vitro release profile showed the FFC-SLN suspension had sustained release effect. The minimum inhibition concentration values of the FFC-SLN suspension were 6 and 3 µg/mL against Staphylococcus aureus and Escherichia coli respectively, compared with 3.5 and 2 µg/mL of native florfenicol. The suspension was relatively stable at 4°C and less stable at room temperature during 9 months storage. Although the nanoparticle carriers exhibited cytotoxicity in cell cultures, the LD50 of the lyophilised dry power of the suspension was higher than 5 g/kg body weight. Mortality protection against E. coli lethal infection in mice showed that the nanoparticle suspension had much better efficacy (6/10) than native drug (1/10). These results indicate that FFC-SLN suspension could be a promising formulation in veterinary medicine.
Kim, Byung-Do; Na, Kun; Choi, Hoo-Kyun
Solid lipid nanoparticles (SLN) were prepared using cacao butter, as the lipid core, and curdlan, as the shell material. Tween 80 was used as a co-surfactant in order to prevent aggregation and gelling of the curdlan. Mannitol was used as a cryoprotectant in order to prevent aggregation during redispersion. No significant change in the size of the SLN was observed up to a lipid concentration of 1.0%, and the particle size ranged from 140 to 200 nm with a unimodal distribution. When an alternating pH between 7 and 11 was used to test the physical stability of an SLN solution, the change in the particle size remained within a narrow range up to a lipid concentration of 0.5%. Above 0.5%, the particles began to aggregate due to the insufficient amount of the coating material, curdlan and Tween 80. The critical aggregation concentration at pH 7.4 was found to be 6.95 x 10(-4) mg/ml. Pyrene was used as a fluorescence probe. As the temperature increased, pyrene was gradually released from the SLN. The loading efficiency was >75% when the verapamil to lipid ratios were 1:10 and 1:5 and decreased significantly as the ratio became 1:1. The release rate was significantly delayed when verapamil was loaded into the SLN.
Singh, Bhupender; Vuddanda, Parameswara Rao; M R, Vijayakumar; Kumar, Vinod; Saxena, Preeti S; Singh, Sanjay
The present research work is focused on the development of solid lipid nanoparticles of cefuroxime axetil (CA-SLN) for its enhanced inhibitory activity against Staphylococcus aureus produced biofilm. CA-SLN was prepared by solvent emulsification/evaporation method using single lipid (stearic acid (SA)) and binary lipids (SA and tristearin (TS)). Process variables such as volume of dispersion medium, concentration of surfactant, homogenization speed and time were optimized. The prepared SLN were characterized for encapsulation efficiency, drug polymer interaction studies (DSC and FT-IR), shape and surface morphology (SEM and AFM), in vitro drug release, stability studies and in vitro anti biofilm activity against S. aureus biofilm. Among the process variables, increased volume of dispersion medium, homogenization speed and time led to increase in particle size whereas increase in surfactant concentration decreased the particle size. SLN prepared using binary lipids exhibited higher entrapment efficiency than the single lipid. DSC and FT-IR studies showed no incompatible interaction between drug and excipients. CA-SLN showed two folds higher anti-biofilm activity in vitro than pristine CA against S. aureus biofilm.
Raj, Rakesh; Mongia, Pooja; Ram, Alpana; Jain, N K
The aim of the present study was to develop solid lipid nanoparticles (SLN) and formulate a hydrogel for enhanced topical delivery of aceclofenac (ACF). The SLN were prepared by the ultrasonic emulsification method and optimized on the basis of stirring speed and lipid content. The optimized formulation was characterized for particle size (189 ± 9.2 nm), polydispersity index (PDI) (0.162 ± 0.02), zeta potential (-32.51 ± 0.12 mV), entrapment efficiency (86.51 ± 2.46%), surface morphology, differential scanning calorimetry (DSC) and X-ray diffraction (XRD). In vivo performance of ACF-loaded SLN hydrogel showed prolonged inhibition of edema, as compared to that observed using plain ACF hydrogel, after 24 h. The results demonstrated that the ACF-SLN formulation for skin targeting could be a promising carrier for topical delivery of ACF.
Ridolfi, D. M.; Marcato, P. D.; Machado, D.; Silva, R. A.; Justo, G. Z.; Durán, N.
In recent years, the interest in nanostructured systems to drug delivery has increased because they offer several advantages over conventional dosage forms. Solid Lipid Nanoparticles (SLN) have been highlighted among these systems because they have advantages such as high physical stability, protection against drug degradation and ease of scale-up and manufacturing, without using organic solvent. The aim of this work was to evaluate the potential of SLN, by in vitro cytotoxicity assays, for dermal drug delivery. SLN of three different lipids were prepared by hot high pressure homogenization and the cytotoxicity was assessed by 3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyl tetrazolium bromide (MTT) test in mouse 3T3 fibroblasts and human HaCaT keratinocytes. SLN showed no cytotoxic potential suggesting a great potential for dermal application.
Oehlke, Kathleen; Behsnilian, Diana; Mayer-Miebach, Esther; Weidler, Peter G.; Greiner, Ralf
Ferulic acid (FA) and tocopherol (Toc) loaded solid lipid nanoparticles (SLN) were prepared by a hot homogenisation method. The particle size distribution, zeta potential and melting behaviour of the SLN as well as the stability, encapsulation efficiency and radical scavenging activity of FA and Toc in the SLN were analysed. The different formulations containing up to 2.8 mg g−1 of FA or Toc were stable during at least 15 weeks of storage at room temperature. Despite partial degradation and / or release of FA and Toc during storage, significant radical scavenging activity was maintained. DSC measurements and radical scavenging tests after different time periods revealed that the re-structuring of the lipid matrix was connected to the enhanced antioxidant activity of Toc but did not affect the activity of FA. PMID:28192494
Chirio, Daniela; Gallarate, Marina; Peira, Elena; Battaglia, Luigi; Serpe, Loredana; Trotta, Michele
Curcumin (CU) loaded solid lipid nanoparticles (SLNs) of fatty acids (FA) were prepared with a coacervation technique based on FA precipitation from their sodium salt micelles in the presence of polymeric non-ionic surfactants. Myristic, palmitic, stearic, and behenic acids, and different polymers with various molecular weights and hydrolysis grades were employed as lipid matrixes and stabilisers, respectively. Generally, spherical-shaped nanoparticles with mean diameters below 500 nm were obtained, and using only middle-high hydrolysis, grade-polymer SLNs with diameters lower than 300 nm were produced. CU encapsulation efficiency was in the range 28-81% and highly influenced by both FA and polymer type. Chitosan hydrochloride was added to FA SLN formulations to produce bioadhesive, positively charged nanoparticles. A CU-chitosan complex formation could be hypothesised by DSC analysis, UV-vis spectra and chitosan surface tension determination. A preliminary study on HCT-116 colon cancer cells was developed to evaluate the influence of CU-loaded FA SLNs on cell viability.
Gaspar, Diana P; Faria, Vasco; Gonçalves, Lídia M D; Taboada, Pablo; Remuñán-López, Carmen; Almeida, António J
Systemic administration of antitubercular drugs can be complicated by off-target toxicity to cells and tissues that are not infected by Mycobacterium tuberculosis . Delivery of antitubercular drugs via nanoparticles directly to the infected cells has the potential to maximize efficacy and minimize toxicity. The present work demonstrates the potential of solid lipid nanoparticles (SLN) as a delivery platform for rifabutin (RFB). Two different RFB-containing SLN formulations were produced using glyceryl dibehenate or glyceryl tristearate as lipid components. Full characterization was performed in terms of particle size, encapsulation and loading efficiency, morphology by transmission electron microscopy (TEM) and differential scanning calorimetry (DSC) studies. Physical stability was evaluated when formulations were stored at 5 ± 3°C and in the freeze-dried form. Formulations were stable throughout lyophilization without significant variations on physicochemical properties and RFB losses. The SLN showed to be able to endure harsh temperature conditions as demonstrated by dynamic light scattering (DLS). Release studies revealed that RFB was almost completely released from SLN. In vitro studies with THP1 cells differentiated in macrophages showing a nanoparticle uptake of 46 ± 3% and 26 ± 9% for glyceryl dibehenate and glyceryl tristearate SLN, respectively. Cell viability studies using relevant lung cell lines (A549 and Calu-3) revealed low cytotoxicity for the SLN, suggesting these could be new potential vehicles for pulmonary delivery of antitubercular drugs.
Deshpande, Ameya Abhay
The aim of this research was to formulate, characterize, and evaluate the paclitaxel loaded solid lipid nanoparticles (SLNs) prepared by a temperature modulated solidification technique developed and optimized in our laboratory. The particle size analysis through dynamic light scattering (DLS) and transmission electron microscopy (TEM) revealed and confirmed the spherical shape and nanometer size range of the formulated nanoparticles. Zeta potential measurements confirmed the physical stability of the SLNs with a negative surface charge. Atomic force microscopy (AFM) studies were done to study the surface topography and particle size and shape. AFM data showed minimal aggregation and more or less spherical SLNs. Differential scanning calorimetry (DSC), powder X-ray diffraction (P-XRD) and Fourier transform infrared spectroscopy (ATR-FTIR) confirmed the conversion of bulk lipid into SLNs and high entrapment of paclitaxel into the lipid matrix. The optimized formulation had an entrapment efficiency of approximately 62%. The in-vitro drug release depicted a sustained release of paclitaxel from the SLNs over duration of one week. The drug release data was found to best fit and hence followed the Higuchi drug-release model.
Majrad, Mohamed Saleh
The primary goal of this research work was to develop solid lipid nanoparticles (SLNs) containing 5-Flourouracil and to evaluate its effect on various cell lines. The solid lipid nanoparticles were prepared through a new temperature modulated solidification technique developed in our laboratory. Particle size analysis by dynamic light scattering (DLS) and morphology evaluation by transmission electron microscopy (TEM) demonstrated that the SLNs are nanoparticulates. Cytotoxic activity of SLN loaded 5-Fluorouracil showed a decrease in viability when compared to pure solution of 5-FU on PC-3 and Caco-2 cell line. Blank SLN showed no decrease in cell viability when the concentration increased. Biocompatibility studies of SLNs in human RBCs indicated that 5-FU SLN formulations are compatible. Bovine permeability study shows that apparent permeability for 5-FU SLN was 0.000348 cm/s and 1.339 cm/s for 5-FU solution. The preliminary results from various in vitro evaluations suggest that 5-FU loaded SLNs have the potential to be used as an anti-cancer drug delivery system.
Carneiro, Zumira A.; da S. Maia, Pedro I.; Sesti-Costa, Renata; Lopes, Carla D.; Pereira, Tatiana A.; Milanezi, Cristiane M.; da Silva, Marcelo A. Pereira.; Lopez, Renata F. V.; Silva, João S.; Deflon, Victor M.
The parasite Trypanosoma cruzi causes Chagas disease, which remains a serious public health concern and continues to victimize thousands of people, primarily in the poorest regions of Latin America. In the search for new therapeutic drugs against T. cruzi, here we have evaluated both the in vitro and the in vivo activity of 5-hydroxy-3-methyl-5-phenyl-pyrazoline-1-(S-benzyl dithiocarbazate) (H2bdtc) as a free compound or encapsulated into solid lipid nanoparticles (SLN); we compared the results with those achieved by using the currently employed drug, benznidazole. H2bdtc encapsulated into solid lipid nanoparticles (a) effectively reduced parasitemia in mice at concentrations 100 times lower than that normally employed for benznidazole (clinically applied at a concentration of 400 µmol kg−1 day−1); (b) diminished inflammation and lesions of the liver and heart; and (c) resulted in 100% survival of mice infected with T. cruzi. Therefore, H2bdtc is a potent trypanocidal agent. PMID:24810753
Battani, Somashekhar; Pawar, Harish; Suresh, Sarasija
The objective of the present investigation was formulation of raloxifene loaded solid lipid nanoparticles (R-SLN) for oral administration and evaluation of its anticancer potential in 7,12- dimethylbenzanthracene (DMBA)-induced breast cancer in Sprague-Dawley rats. Optimized R-SLN formulation prepared by modified micro-emulsion method resulted in R-SLN of 288.0±28.5 nm size and 95.56% entrapment efficiency. R-SLN exhibited in vitro prolonged release of raloxifene for 72 h in phosphate buffered saline. R-SLN was stable in simulated gastro-intestinal (GIT) fluids consisting of pH 1.2, pH 7.4, simulated gastric fluid and simulated intestinal fluid. A two-fold increase was observed in raloxifene oral bioavailability from R-SLN. R-SLN exhibited enhanced efficacy and chemopreventive activity over pure raloxifene as indicated by evaluation of tumor burden (P < 0.001) and tumor incidence (P < 0.001). The results indicate the potential of raloxifene solid lipid nanoparticles in optimizing chemoprevention of breast cancer by R-SLN.
Karmakar, Gourab; Nahak, Prasant; Guha, Pritam; Roy, Biplab; Chettri, Priyam; Sapkota, Manish; Koirala, Suraj; Misono, Takeshi; Torigoe, Kanjiro; Ghosh, Shilpi; Panda, Amiya Kumar
Mutual miscibility of soylecithin, tristearin, fatty acids (FAs), and curcumin was assessed by means of surface pressure-area isotherms at the air-solution interface in order to formulate modified solid lipid nanoparticles (SLN). Appearance of minima in the excess area (Aex) and changes in free energy of mixing (∆G(0)ex) were recorded for systems with 20 mole% FAs. Modified SLNs, promising as topical drug delivery systems, were formulated using the lipids in combination with curcumin, stabilized by an aqueous Tween 60 solution. Optimal formulations were assessed by judiciously varying the FA chain length and composition. Physicochemical properties of SLNs were studied such as the size, zeta potential (by dynamic light scattering), morphology (by freeze fracture transmission electron microscopy), and thermal behavior (by differential scanning calorimetry). The size and zeta potential of the formulations were in the range 300-500 nm and -10 to -20 mV, respectively. Absorption and emission spectroscopic analyses supported the dynamic light scattering and differential scanning calorimetry data and confirmed localization of curcumin to the palisade layer of SLNs. These nanoparticles showed a sustained release of incorporated curcumin. Curcumin-loaded SLNs were effective against a gram-positive bacterial species, Bacillus amyloliquefaciens. Our results on the physicochemical properties of curcumin-loaded SLNs, the sustained release, and on antibacterial activity suggest that SLNs are promising delivery agents for topical drugs.
Doktorovová, Slavomira; Santos, Dario L; Costa, Inês; Andreani, Tatiana; Souto, Eliana B; Silva, Amélia M
Solid lipid nanoparticles (SLN) are colloidal drug and/or gene carriers developed from solid lipids and surfactants that are considered safe. Cationic SLN, usually used for formulating poorly water-soluble drugs and for gene delivery purposes, as positively charged particles may attach to cellular surfaces and be internalized more easily than negatively charged SLN, but they can also cause damage. The main aim of this work was to test a set of cationic SLN and investigate its influence on the amount of reactive oxygen species (ROS), on antioxidant enzymes activities and on possible oxidative damage to membrane lipids in HepG2 cells. The Dichlorofluorescein assay revealed great increase in ROS presence after cell exposure to SLN. While the exposure to SLN increased the activities of superoxide dismutase and glutathione peroxidase it decreased glutathione reductase activity. Although no significant increase in thiobarbituric reactive species was found, a decrease in sulfhydryl groups was detected. These results indicate that cationic SLN caused oxidative stress in HepG2 cells, but under reported exposure conditions HepG2 cells could attenuate the stress and thus the damage to cellular components was minimal.
Dal Pizzol, Carine; O'Reilly, Andre; Winter, Evelyn; Sonaglio, Diva; de Campos, Angela Machado; Creczynski-Pasa, Tânia Beatriz
Solid lipid nanoparticles (SLN) are colloidal particles consisting of a matrix composed of solid (at room and body temperatures) lipids dispersed in aqueous emulsifier solution. During manufacture, their physicochemical properties may be affected by several formulation parameters, such as type and concentration of lipid, proportion of emulsifiers and amount of solvent. Thus, the aim of this work was to study the influence of these variables on the preparation of SLN. A D-optimal Response Surface Methodology design was used to establish a mathematical model for the optimization of SLN. A total of 30 SLN formulations were prepared using the ultrasound method, and then characterized on the basis of their physicochemical properties, including particle size, polydispersity index (PI) and Zeta Potential (s). Particle sizes ranged between 107 and 240 nm. All SLN formulations showed negative sigma and PI values below 0.28. Prediction of the optimal conditions was performed using the desirability function targeting the reduction of all responses. The optimized SLN formulation showed similar theoretical and experimental values, confirming the sturdiness and predictive ability of the mathematical model for SLN optimization.
Solid lipid nanoparticles (SLNs) consist of spherical solid lipid particles in the nanometer size range, which are dispersed in water or in an aqueous surfactant solution. SLN technology represents a promising new approach to deliver hydrophilic as well as lipophilic drugs. The commercialization of SLN technology remains limited despite numerous efforts from researchers. The purpose of this research was to advance SLN preparation methodology by investigating the feasibility of preparing glyceryl monostearate (GMS) nanoparticles by using three preparation methods namely microemulsion technique, magnetic stirring technique and temperature modulated solidification technique of which the latter two were developed in our laboratory. An anticancer drug 5-fluorouracil was incorporated in the SLNs prepared via the temperature modulated solidification process. Optimization of the magnetic stirring process was performed to evaluate how the physicochemical properties of the SLN was influenced by systematically varying process parameters including concentration of the lipid, concentration of the surfactant, type of surfactant, time of stirring and temperature of storage. The results demonstrated 1:2 GMS to tween 80 ratio, 150 ml dispersion medium and 45 min stirring at 4000 RPM speed provided an optimum formulation via the temperature modulated solidification process. SLN dispersions were lyophilized to stabilize the solid lipid nanoparticles and the lyophilizates exhibited good redispersibility. The SLNs were characterized by particle size analysis via dynamic light scattering (DLS), zeta potential, transmission electron microscopy (TEM), differential scanning calorimetry (DSC), drug encapsulation efficiency and in vitro drug release studies. Particle size of SLN dispersion prepared via the three preparation techniques was approximately 66 nm and that of redispersed lyophilizates was below 500 nm. TEM images showed spherical to oval particles that were less dense in the core
Gaur, Praveen Kumar; Mishra, Shikha; Bajpai, Meenakshi; Mishra, Anushika
Solid lipid nanoparticle is an efficient lipid based drug delivery system which can enhance the bioavailability of poorly water soluble drugs. Efavirenz is a highly lipophilic drug from nonnucleoside inhibitor category for treatment of HIV. Present work illustrates development of an SLN formulation for Efavirenz with increased bioavailability. At first, suitable lipid component and surfactant were chosen. SLNs were prepared and analyzed for physical parameters, stability, and pharmacokinetic profile. Efavirenz loaded SLNs were formulated using Glyceryl monostearate as main lipid and Tween 80 as surfactant. ESLN-3 has shown mean particle size of 124.5 ± 3.2 nm with a PDI value of 0.234, negative zeta potential, and 86% drug entrapment. In vitro drug release study has shown 60.6–98.22% drug release in 24 h by various SLN formulations. Optimized SLNs have shown good stability at 40°C ± 2°C and 75 ± 5% relative humidity (RH) for 180 days. ESLN-3 exhibited 5.32-fold increase in peak plasma concentration (Cmax) and 10.98-fold increase in AUC in comparison to Efavirenz suspension (ES). PMID:24967360
Chai, Gui-Hong; Hu, Fu-Qiang; Sun, Jihong; Du, Yong-Zhong; You, Jian; Yuan, Hong
An understanding of drug delivery system transport across epithelial cell monolayer is very important for improving the absorption and bioavailability of the drug payload. The mechanisms of epithelial cell monolayer transport for various nanocarriers may differ significantly due to their variable components, surface properties, or diameter. Solid lipid nanoparticles (SLNs), conventionally formed by lipid materials, have gained increasing attention in recent years due to their excellent biocompatibility and high oral bioavailability. However, there have been few reports about the mechanisms of SLNs transport across epithelial cell monolayer. In this study, the molecular mechanisms utilized by SLNs of approximately 100 nm in diameter crossing intestinal epithelial monolayer were carefully studied using a simulative intestinal epithelial monolayer formed by Madin-Darby canine kidney (MDCK) epithelial cells. The results demonstrated that SLNs transportation did not induce a significant change on tight junction structure. We found that the endocytosis of SLNs into the epithelial cells was energy-dependent and was significantly greater than nanoparticle exocytosis. The endocytosis of SLNs was found to be rarely mediated via macropinocytosis, as confirmed by the addition of 5-(N-ethyl-N-isopropyl)amiloride (EIPA) as an inhibitory agent, and mainly depended on lipid raft/caveolae- and clathrin-mediated pathways. After SLNs was internalized into MDCK cells, lysosome was one of the main destinations for these nanoparticles. The exocytosis study indicated that the endoplasmic reticulum, Golgi complex, and microtubules played important roles in the transport of SLNs out of MDCK cells. The transcytosis study indicated that only approximately 2.5% of the total SLNs was transported from the apical side to the basolateral side. For SLNs transportation in MDCK cell monolayer, greater transport (approximately 4-fold) was observed to the apical side than to the basolateral side. Our
Xu, Qiang; Zhu, Tao; Yi, Chaoli; Shen, Qi
Considered a popular drug for diabetes in recent years, metformin was determined to have a moderate anti-tumor effect, particularly in breast cancer. In this study, the anticancer mechanism of metformin was verified by preparing solid lipid nanoparticles (SLNs) and chitosan-modified solid lipid nanoparticles (CSLNs) containing metformin and then estimating the potential of these SLNs for uptake in cells and mitochondria. Metformin-SLNs were prepared using an emulsification and low-temperature solidification method. The mean particle size, zeta potential, entrapment efficiency, and loading efficiency of metformin-SLNs and metformin chitosan-modified SLNs were 102.3 ± 4.16 and 200.1 ± 17.69 nm, -21.25 ± 4.89 and 50.6 ± 4.09 mv, 26.25 ± 2.59% and 33.6 ± 2.21%, and 1.74 ± 0.16% and 1.46 ± 0.10%, respectively. TEM images showed that both the nanoparticles had spherical morphologies with no aggregation. Results of cellular and mitochondrial uptake showed that the metformin-SLNs were easier to uptake in cells and mitochondria than the pure drug group (that was the control group without SLN structure modification). The findings of this research provide a basis for conducting further studies on the anticancer mechanism of metformin.
Nasseri, Mahboobeh; Golmohammadzadeh, Shiva; Arouiee, Hossein; Jaafari, Mahmoud Reza; Neamati, Hossein
Objective(s): The aim of the present study was to prepare, characterize, and evaluate solid lipid nanoparticles (SLNs) containing Zataria multiflora essential oil (ZEO). Materials and Methods: In this study, Z. multiflora essential oil-loaded solid lipid nanoparticles (ZE-SLNs) were prepared to improve its efficiency in controlling some fungal pathogens. SLNs containing Z. multiflora essential oil were prepared by high shear homogenization and ultra sound technique. ZEO-SLNs contained 0.03% ZEO in 5% of lipid phase (Glyceryl monostearate-GMS and Precirol® ATO 5). Tween 80 and Poloxamer 188 (2.5% w/v) were used as surfactant in the aqueous phase. The antifungal efficacy of ZE-SLNs and ZEO was compared under in vitro conditions. Results: The particle size of ZE-SLNs was around 255.5±3 nm with PDI of 0.369±0.05 and zeta potential was about -37.8±0.8 mV. Encapsulation efficacy of ZE-SLNs in crystalline form was 84±0.92%. The results showed that the ZEO and ZE-SLNs had 54 and 79% inhibition on the growth of fungal pathogens, respectively. The minimum inhibitory concentration (MIC) under in vitro conditions for the ZEO on the fungal pathogens of Aspergillus ochraceus, Aspergillus niger, Aspergillus flavus, Alternaria solani, Rhizoctonia solani, and Rhizopus stolonifer was 300, 200, 300, 200, 200 and 200 ppm, respectively, for ZE-SLNs, it was 200, 200, 200, 100, 50 and 50 ppm. The antifungal efficacy of ZE-SLNs was significantly more than ZEO. Conclusion: Our results showed that the SLNs were suitable carriers for Z. multiflora essential oil in controlling the fungal pathogens and merits further investigation. PMID:27917280
Shegokar, R; Singh, K K; Müller, R H
The production of stavudine-loaded solid lipid nanoparticles (SLN) for intravenous injection was scaled up from lab scale (40 g) to medium scale (10 kg) and large scale (20/60 kg). The SLN were produced by high pressure homogenization of stavudine lipid melt dispersed in hot surfactant solution (pre-emulsion) applying 800 bar pressure. Employed were piston-gap homogenizers with increasing capacity (APV Gaulin products LAB 40, LAB 60 and Gaulin 5.5, and Avestin C50), using them in the continuous (circulation) and discontinuous mode. Size analysis was performed by photon correlation spectroscopy (PCS), laser diffractometry and light microscopy. At lab scale a PCS size of 53 nm was obtained. At the same pressure, all homogenizers on larger scale yielded a size in the range of the lab scale product (35-70 nm). Differences were found in the size as a function of circulation time (size increase or size reduction with time) and the number of cycles required (1 or 5) for the optimal product. The stavudine SLN formulation (2% lipid content, high surfactant to lipid ratio) showed a different behavior to conventional higher concentrated SLN suspensions or nanoemulsions (10% or 20% lipid/oil, low surfactant to lipid ratio). In general, smallest sizes were obtained in the discontinuous mode after just one homogenization cycle. The continuous production mode was only efficient with a 10 kg batch size using the LAB 60. In addition, the long-term stability over 1 year was monitored at refrigeration, room temperature and at 40°C to assess a potential effect of the homogenizer type on stability. All batches at room temperature and below were stable, only a negligible increase in size was observed.
Gonçalves, L M D; Maestrelli, F; Di Cesare Mannelli, L; Ghelardini, C; Almeida, A J; Mura, P
A solid lipid nanoparticle (SLN) formulation was developed with the aim of improving the oral bioavailability and the therapeutic effectiveness of glibenclamide (GLI), a poorly water-soluble drug used in the treatment of type 2 diabetes. The SLN was prepared using different lipid components (Precirol® and Compritol®) and preparation procedures. Precirol-based SLN, obtained with the emulsion of solvent evaporation technique gave the best results and was selected for drug loading. Addition of lecithin to the SLN core or PEG coating was effective in increasing the nanoparticles stability in simulated gastric solution. Both such formulations were stable after one month storage at 5±3°C, exhibited the absence of in vitro cytotoxicity, and presented a similar in vitro prolonged-release, reaching 100% release after 24h. The lecithin-containing GLI-loaded SLN formulation, selected for in vivo studies in virtue of its higher EE% than the PEG-coated formulation (70.3% vs 19.6%), showed a significantly stronger hypoglycemic effect with respect to the drug alone, in terms of both shorter onset time and longer duration of the effect. These positive results indicated that the proposed SLN approach was successful in improving GLI oral bioavailability, confirming its potential as an effective delivery system for a suitable therapy of diabetes.
Akanda, Mushfiq H; Rai, Rajeev; Slipper, Ian J; Chowdhry, Babur Z; Lamprou, Dimitrios; Getti, Giulia; Douroumis, Dennis
In this study retinoic acid (RTA) loaded solid lipid nanoparticles (SLNs) were optimized by tuning the process parameters (pressure/temperature) and using different lipids to develop nanodispersions with enhanced anticancer activity. The RTA-SLN dispersions were produced by high-pressure homogenization and characterized in terms of particle size, zeta potential, drug entrapment efficiency, stability, transmission electron microscopy (TEM), atomic force microscopy (AFM), X-ray diffraction (XRD) and in vitro drug release. Thermal and X-ray analysis showed the RTA to be in the amorphous state, whilst microscopic images revealed a spherical shape and uniform particle size distribution of the nanoparticles. Anticancer efficiency was evaluated by incubating RTA-SLNs with human prostate cancer (LNCap) cells, which demonstrated reduced cell viability with increased drug concentrations (9.53% at 200 ug/ml) while blank SLNs displayed negligible cytotoxicity. The cellular uptake of SLN showed localization within the cytoplasm of cells and flow cytometry analysis indicated an increase in the fraction of cells expressing early apoptotic markers, suggesting that the RTA loaded SLNs are able to induce apoptosis in LNCap cells. The RTA-SLN dispersions have the potential to be used for prostate anticancer treatment.
Leonardi, Antonio; Crasci', Lucia; Panico, Annamaria; Pignatello, Rosario
Idebenone (IDE) is a lipophilic benzoquinone electron carrier synthetic analogue of coenzyme Q10, which behaves as an antioxidant and free radical scavenging molecule. Recently, the therapeutic application of IDE in Leber's hereditary optic neuropathy has been discussed. This work was aimed at evaluating the encapsulation of IDE in solid-lipid nanoparticles (SLN). In particular, we tested the possibility of adapting the quasi-emulsion solvent diffusion technique, already proposed to produce polymeric nanoparticles, to prepare positively charged SLN with different compositions. Such a charge, due to the addition of a cationic lipid, would facilitate the interaction with the negatively charged eye surface epithelium, with a consequent longer pre-corneal residence time of the colloidal systems. In a preliminary evaluation of the produced IDE-loaded SLN, the antioxidant activity of the drug was demonstrated using an oxygen radical absorbance capacity assay. Encapsulation of the drug in the nanocarrier systems seems able to protect IDE from degradation and prolong its antioxidant potential.
Keck, Cornelia M; Kovačević, Andjelka; Müller, Rainer H; Savić, Snežana; Vuleta, Gordana; Milić, Jela
Alkyl polyglycosides (APGs) represent a group of nonionic tensides with excellent skin compatibility. Thus they seem to be excellent stabilizers for lipid nanoparticles for dermal application. To investigate this, different APGs were selected to evaluate their influence on the formation and characteristics of solid lipid nanoparticles (SLN). Contact angle analysis of the aqueous solutions/dispersions of the APGs on cetyl palmitate films revealed good wettability for all APG surfactants. Cetyl palmitate based SLN were prepared by hot high pressure homogenization and subjected to particle size, charge and inner structure analysis. 1% of each APG was sufficient to obtain SLN with a mean size between 150 nm and 175 nm and a narrow size distribution. The zeta potential in water was ∼ -50 mV; the values in the original medium were distinctly lower, but still sufficient high to provide good physical stability. Physical stability at different temperatures (5°C, 25°C and 40°C) was confirmed by a constant particle size over an observation period of 90 days in all dispersions. In comparison to SLN stabilized with classical surfactants, e.g., Polysorbate, APG stabilized SLN possess a smaller size, improved physical stability and contain less surfactant. Therefore, the use of APGs for the stabilization of lipid nanoparticles is superior in comparison to classical stabilizers. Further, the results indicate that the length of the alkyl chain of the APG influences the diminution efficacy, the final particle size and the crystallinity of the particles. APGs with short alkyl chain led to a faster reduction in size during high pressure homogenization, to a smaller particle size of the SLN and to a lower recrystallization index, i.e., to a lower crystallinity of the SLN. The crystallinity of the SLN increased with an increase in the alkyl chain length of APGs. Therefore, by using the tested APGs differing in the alkyl chain length, not only small sized and physically stable but
Wang, Taoran; Hu, Qiaobin; Zhou, Mingyong; Xue, Jingyi; Luo, Yangchao
In this study, five polysaccharides were applied as natural polymeric coating materials to prepare solid lipid nanoparticles (SLN) and nanostructure lipid carriers (NLC), and then the obtained lipid colloidal particles were transformed to solid powders by the innovative nano spray drying technology. The feasibility and suitability of this new technology to generate ultra-fine lipid powder particles were evaluated and the formulation was optimized. The spray dried SLN powder exhibited the aggregated and irregular shape and dimension, but small, uniform, well-separated spherical powder particles of was obtained from NLC. The optimal formulation of NLC was prepared by a 20-30% oleic acid content with carrageenan or pectin as coating material. Therefore, nano spray drying technology has a potential application to produce uniform, spherical, and sub-microscale lipid powder particles when the formulation of lipid delivery system is appropriately designed.
Cavaco, Marco C; Pereira, Carolina; Kreutzer, Bruna; Gouveia, Luis F; Silva-Lima, Beatriz; Brito, Alexandra M; Videira, Mafalda
Multidrug resistance (MDR), whereby cancer cells become resistant to the cytotoxic effects of various structurally and mechanistically unrelated chemotherapeutic agents, is a major problem in the clinical treatment of cancer. P-glycoprotein (P-gp) is a transmembrane protein responsible for drug efflux, which decreases drug intracellular bioavailability, consequently decreasing their efficacy against cancer. Solid Lipid Nanoparticles (SLNs) have not only the ability to protect the entrapped drug against proteolytic degradation, but also allow a selective intracellular targeting. Hypothetically, the entrapped drug enter the target cells by different uptake mechanisms, "nanocitose", as compared to the free drug and may evade efflux-transporters, like P-gp. The functional role of P-gp in limiting the permeability of the anticancer drug paclitaxel (Ptx) was assessed in MDA-MB-436 cells. The observed increase in the pharmacologic efficacy of drug entrapped in SLN relatively to the free drug indicates that this system is shielding the drug. Therefore, "blinding" the nanoparticle from the efflux transporters. The effect was confirmed by the decrease expression of P-gp with loaded-SLNs and through the impact on cellular MDR1 expression. Besides the ability to prevent MDR events, functionalization of SLN with a specific antibody against membrane receptors (anti-CD44v6) improves the nanoparticle capability to target selectively malignant cells. This results allow to anticipate that poor clinical outcomes related to tumour P-gp overexpression might be overcome in a near future.
Nunes, Sara; Madureira, Ana Raquel; Campos, Débora; Sarmento, Bruno; Gomes, Ana Maria; Pintado, Manuela; Reis, Flávio
Drug delivery systems, accompanied by nanoparticle technology, have recently emerged as prominent solutions to improve the pharmacokinetic properties, namely bioavailability, of therapeutic and nutraceutical agents. Solid lipid nanoparticles (SLNs) have received much attention from researchers due to their potential to protect or improve drug properties. SLNs have been reported to be an alternative system to traditional carriers, such as emulsions, liposomes, and polymeric nanoparticles. Phenolic compounds are widespread in plant-derived foodstuffs and therefore abundant in our diet. Over the last decades, phenolic compounds have received considerable attention due to several health promoting properties, mostly related to their antioxidant activity, which can have important implications for health. However, most of these compounds have been associated with poor bioavailability being poorly absorbed, rapidly metabolized and eliminated, which compromises its biological and pharmacological benefits. This paper provides a systematic review of the use of SLNs as oral delivery systems of phenolic compounds, in order to overcome pharmacokinetic limitations of these compounds and improved nutraceutical potential. In vitro studies, as well as works describing topical and oral treatments will be revisited and discussed. The classification, synthesis, and clinical application of these nanomaterials will be also considered in this review article.
Calderón-Colón, Xiomara; Patchan, Marcia W.; Theodore, Mellisa L.; Le, Huong T.; Sample, Jennifer L.; Benkoski, Jason J.; Patrone, Julia B.
Solid lipid nanoparticles (SLNs) are a promising platform for sensing in vivo biomarkers due to their biocompatibility, stability, and their ability to carry a wide range of active ingredients. The skin is a prominent target organ for numerous inflammatory and stress-related biomarkers, making it an excellent site for early detection of physiological imbalance and application of sensory nanoparticles. Though smaller particle size has generally been correlated with increased penetration of skin models, there has been little attention paid to the significance of other nanoparticle synthesis parameters with respect to their physical properties. In this study, we demonstrate the synthesis of sub-10 nm SLNs by the phase inversion temperature (PIT) method. These particles were specifically designed for topical delivery of hydrogen peroxide-detecting chemiluminescent dyes. A systematic design of experiments approach was used to investigate the role of the processing variables on SLN form and properties. The processing variables were correlated with the SLN properties (e.g., dye solubility, phase inversion temperature, particle size, polydispersity, melting point, and latent heat of melting). Statistical analysis revealed that the PIT method, while allowing total control over the thermal properties, resulted in well-controlled synthesis of ultra-small particles, while allowing great flexibility in the processing conditions and incorporated compounds.
Ghaffari, Solmaz; Varshosaz, Jaleh; Saadat, Afrooz; Atyabi, Fatemeh
Solid lipid nanoparticles (SLNs) of amikacin were designed in this study for pulmonary delivery to reduce the dose or its administration intervals leading to reduction of its toxicities especially in long term treatment. Nanoparticles of amikacin were prepared from cholesterol by solvent diffusion technique and homogenization. The size, zeta potential, loading efficiency, and release profile of the nanoparticles were studied. The conventional broth macrodilution tube method was used to determine the minimum inhibitory concentration (MIC) and minimum bacteriostatic concentration (MBC) of amikacin SLNs with respect to Pseudomonas aeruginosa in vitro. To guarantee the stability of desired SLNs, they were lyophilized using cryoprotectants. Results showed that considering the release profile of amikacin from the studied nanocarrier, MIC and MBC of amikacin could be about two times less in SLNs of amikacin compared to the free drug. Therefore, fewer doses of amikacin in SLNs can clear the infection with less adverse effects and more safety. Particle size enlargement after lyophilization of desired SLNs after two months storage was limited in comparison with non-lyophilized particles, 996 and 194 nm, respectively. Zeta potential of lyophilized particles was increased to +17 mV from +4 mV before lyophilization. Storage of particles in higher temperature caused accelerated drug release. PMID:21289980
Khurana, S; Bedi, P M S; Jain, N K
The aim of the current investigation was to prepare and investigate the potential of solid lipid nanoparticles based gel (SLN-gel) for the dermal delivery of meloxicam (MLX). The meloxicam loaded SLN (MLX-SLN) gel was developed and characterized by means of photon correlation spectroscopy, rheometry, and differential scanning calorimetry to determine the physicochemical properties. The behavior of SLN gel on rat skin was evaluated in vitro using Franz diffusion cells to determine the skin permeation and penetration characteristics, in vivo on mice to determine the skin tolerance by histopathological examinations. The anti-inflammatory potential of SLN gel was assessed by carrageenan induced rat paw edema test. Biophysical studies including differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR) were undertaken to study the interaction between the SLN gel and skin. MLX-SLN gel with nanometric particle size exhibited the controlled release abilities and simultaneously the potential to transport the drug to various skin layers. SLN gel displayed viscoelastic properties with predominantly elastic behavior and exhibited plastic flow. Biophysical studies elucidated the interaction between the SLN gel and stratum corneum (SC) lipids, and proposed the lipid bilayer fluidization as the possible mechanism for the increased penetration of meloxicam into skin. The nano-gel system showed marked anti-inflammatory activity and excellent skin tolerability. It can be concluded that SLN gel may be a promising delivery system for MLX in the treatment of inflammatory disorders.
Silva, A C; Kumar, A; Wild, W; Ferreira, D; Santos, D; Forbes, B
A solid lipid nanoparticles (SLN) formulation to improve the oral delivery of risperidone (RISP), a poorly water-soluble drug, was designed and tested. Initially, lipid-RISP solubility was screened to select the best lipid for SLN preparation. Compritol(®)-based formulations were chosen and their long-term stability was assessed over two years of storage (at 25 °C and 4 °C) by means of particle size, polydispersity index (PI), zeta potential (ZP) and encapsulation efficiency (EE) measurements. SLN shape was observed by transmission electron microscopy (TEM) at the beginning and end of the study. The oxidative potential (OP) of the SLN was measured and their biocompatibility with Caco-2 cells was evaluated using the (4,5-dimethylthiazol-2-yl)2,5-dyphenyl-tetrazolium bromide (MTT) assay. In vitro drug release and transport studies were performed to predict the in vivo release profile and to evaluate the drug delivery potential of the SLN formulations, respectively. The RISP-loaded SLN systems were stable and had high EE and similar shape to the placebo formulations before and after storage. Classical Fickian diffusion was identified as the release mechanism for RISP from the SLN formulation. Biocompatibility and dose-dependent RISP transport across Caco-2 cells were observed for the prepared SLN formulations. The viability of SLN as formulations for oral delivery of poorly water-soluble drugs such as RISP was illustrated.
Chen, Zhao-Jie; Zhang, Zhen; Xie, Bei-Bei; Zhang, Hai-Yan
The study aims at statistical development of solid lipid nanoparticles (SLNs) loaded with topotecan hydrochloride for avoiding the drawbacks of conventional drug therapies used in cervical cancer. Twenty SLN batches were prepared using organic solvent evaporation method to provide response surface curves. Thereafter, optimized SLNs were obtained using numeric method based on desirability functions providing maximum drug loading and appropriate particle size. Physical characterization of optimized TPH loaded SLNs was performed in terms of particle size, zeta potential, transmission and scanning electron microscopic evaluation. Cytotoxicity studies were performed against cervical cancer cell lines, including cervical squamous cell carcinoma cell line (HeLa) and human squamous cell carcinoma cell line (SiHa). Also, Swiss mouse embryo fibroblast cells (3T3-L1) and African green monkey kidney epithelial (Vero) cells were used to evaluate biocompatibility in normal cells. As pronounced from the results, optimized SLNs may provide an attractive alternative to conventional cervical cancer drug products.
Das, Shrabanti; Maity, Arnab; Purkayastha, Pradipta
Photophysical modulation of fisetin has been extensively studied in bulk aqueous as well as solid lipid nanoparticles (SLN) by varying the pH of the medium. The solution pH was varied from 5 to 9 to mimic biological environments. Neutral and anionic forms of fisetin coexist in ground state in both acidic and alkaline conditions. However, in the excited state and at low pH, the anionic form of fisetin predominates over the proton transferred form, whereas in SLNs, the proton transferred form is the major emitting species. Higher pH showed enhancement in anionic emission to different extent in the two types of environments. Limited percolation of H(+) and OH(-) ions inside the SLNs that host fisetin molecules controls their photophysics. The experimental results encourage usage of fisetin as a drug depending on the ratio of the neutral and anionic as well as the proton transferred forms under various pH conditions.
Tran, Tuan Hiep; Ramasamy, Thiruganesh; Cho, Hyuk Jun; Kim, Yong Il; Poudel, Bijay Kumar; Choi, Han-Gon; Yong, Chul Soon; Kim, Jong Oh
The main aim of this study was to improve the oral bioavailability of raloxifene (RXF), a selective estrogen receptor modulator, by incorporation into solid lipid nanoparticles (SLN). RXF-loaded SLN was prepared by homogenization-sonication technique and characterized through physicochemical, pharmacokinetic, and cytotoxicity studies. The optimized SLN formulation exhibited a spherical shape with average size around 140 nm, easing its transport across the lymphatic system. Augmentation in the profiles of C(max) (308%) and AUC (270%) indicated a significant enhancement in the rate and extent of bioavailability by SLN formulations compared to free drug. In vitro cytotoxicity study performed in NIH-3T3 cells revealed that RXF-SLN was cytocompatible, and SLN remained unchanged during the freeze-drying process. Furthermore, the optimized formulation was quite stable at room temperature for more than two months, exemplifying its superior performance. In conclusion, SLN provides a promising platform for the pronounced enhancement of RXF bioavailability.
Chai, Gui-Hong; Xu, Yingke; Chen, Shao-Qing; Cheng, Bolin; Hu, Fu-Qiang; You, Jian; Du, Yong-Zhong; Yuan, Hong
Solid lipid nanoparticles (SLNs) have been extensively investigated and demonstrated to be a potential nanocarriers for improving oral bioavailability of many drugs. However, the molecular mechanisms related to this discovery are not yet understood. Here, the molecular transport mechanisms of the SLNs crossing simulative intestinal epithelial cell monolayers (Caco-2 cell monolayers) were studied. The cytotoxicology results of the SLNs in Caco-2 cells demonstrated that the nanoparticles had low cytotoxicity, had no effect on the integrity of the cell membrane, did not induce oxidative stress, and could significantly reduce cell membrane fluidity. The endocytosis of the SLNs was time-dependent, and their delivery was energy-dependent. For the first time, the transport of the SLNs was directly verified to be a vesicle-mediated process. The internalization of the SLNs was mediated by macropinocytosis pathway and clathrin- and caveolae (or lipid raft)-related routes. Transferrin-related endosomes, lysosomes, endoplasmic reticulum (ER), and Golgi apparatus were confirmed to be the main destinations of the SLNs in Caco-2 cells. As for the transport of the SLNs in Caco-2 cell monolayers, the results demonstrated that the SLNs transported to the basolateral side were intact, and the transport of the nanoparticles did not destroy the structure of tight junctions. The transcytosis of the SLNs across the Caco-2 cell monolayer was demonstrated to be mediated by the same routes as that in the endocytosis study. The ER, Golgi apparatus, and microtubules were confirmed to be important for the transport of the SLNs to both the basolateral and apical membrane sides. This study provides a more thoroughly understand of SLNs transportation crossing intestinal epithelial cell monolayers and could be beneficial for the fabrication of SLNs.
Jahanfar, Farhad; Hasani, Akbar; Shanebandi, Dariush; Rahmati, Mohammad; Hamishehkar, Hamed
Purpose: In this study the effectiveness of encapsulating of 5-azacytidine into the lipid nanoparticles was investigated and in vitro effect of encapsulated 5-azacytidine studied on MCF-7 cell lines Methods: 5-azacytidine -loaded solid lipid nanoparticles were produced by double emulsification (w/o/w) method by using stearic acid as lipid matrix, soy lecithin and poloxamer 407 as surfactant and co-surfactant respectively. Particle size, zeta potential, surface morphology, entrapment efficiency and kinetic of drug release were studied. In vitro effect of 5-azacytidine on MCF-7 cell line studied by MTT assay, DAPI staining, Rhodamine B relative uptake, and also Real time RT-PCR was performed for studying difference effect of free and encapsulated drug on expression of RARß2 gene. Results: The formulation F5 with 55.84±0.46 % of entrapment efficiency shows zero order kinetic of drug release and selected for in vitro studies; the cytotoxicity of free drug and encapsulated drug in 48 h of incubation have significant difference. DAPI staining shows morphology of apoptotic nucleus in both free and encapsulated drug, Rhodamine B labeled SLNs show time dependency and accumulation of SLNs in cytoplasm. Real time qRT-PCR doesn’t show any significant difference (p>0.05) in expression of RARß2 gene in both cells treated with free or encapsulated drug. Conclusion: The results of the present study indicated that the entrapment of 5-azacytidine into SLNs enhanced its cytotoxicity performance and may pave a way for the future design of a desired dosage form for 5-azacytidine. PMID:27766220
Hu, Xiongwei; Fan, Wufa; Yu, Zhou; Lu, Yi; Qi, Jianping; Zhang, Jian; Dong, Xiaochun; Zhao, Weili; Wu, Wei
Whether and to what extent solid lipid nanoparticles (SLNs) can be absorbed integrally via oral delivery should be clarified because it is the basis for elucidation of absorption mechanisms. To address this topic, the in vivo fate of SLNs as well as their interaction with biomembranes is investigated using water-quenching fluorescent probes that can signal structural variations of lipid-based nanocarriers. Live imaging indicates prolonged retention of SLNs in the stomach, whereas in the intestine, SLNs can be digested quickly. No translocation of intact SLNs to other organs or tissues can be observed. The in situ perfusion study shows bioadhesion of both SLNs and simulated mixed micelles (SMMs) to intestinal mucus, but no evidence of penetration of integral nanocarriers. Both SLNs and SMMs exhibit significant cellular uptake, but fail to penetrate cell monolayers. Confocal laser scanning microscopy reveals that nanocarriers mainly concentrate on the surface of the monolayers, and no evidence of penetration of intact vehicles can be obtained. The mucous layer acts as a barrier to the penetration of both SLNs and SMMs. Both bile salt-decoration and SMM formulation help to strengthen the interaction with biomembranes. It is concluded that evidence does not support absorption of intact SLNs via oral delivery.Whether and to what extent solid lipid nanoparticles (SLNs) can be absorbed integrally via oral delivery should be clarified because it is the basis for elucidation of absorption mechanisms. To address this topic, the in vivo fate of SLNs as well as their interaction with biomembranes is investigated using water-quenching fluorescent probes that can signal structural variations of lipid-based nanocarriers. Live imaging indicates prolonged retention of SLNs in the stomach, whereas in the intestine, SLNs can be digested quickly. No translocation of intact SLNs to other organs or tissues can be observed. The in situ perfusion study shows bioadhesion of both SLNs and
K S, Joshy; Sharma, Chandra P; Kalarikkal, Nandakumar; Sandeep, K; Thomas, Sabu; Pothen, Laly A
Zidovudine loaded solid lipid nanoparticles of stearic acid modified with Aloe Vera (AV) have been prepared via simple emulsion solvent evaporation method which showed excellent stability at room temperature and refrigerated condition. The nanoparticles were examined by Fourier transform infrared spectroscopy (FT-IR), which revealed the overlap of the AV absorption peak with the absorption peak of modified stearic acid nanoparticles. The inclusion of AV to stearic acid decreased the crystallinity and improved the hydrophilicity of lipid nanoparticles and thereby improved the drug loading efficacy of lipid nanoparticles. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) imaging revealed that, the average particle size of unmodified (bare) nanoparticles was 45.66±12.22nm and modified solid lipid nanoparticles showed an average size of 265.61±80.44nm. Solid lipid nanoparticles with well-defined morphology were tested in vitro for their possible application in drug delivery. Cell culture studies using C6 glioma cells on the nanoparticles showed enhanced growth and proliferation of cells without exhibiting any toxicity. In addition, normal cell morphology and improved uptake were observed by fluorescence microscopy images of rhodamine labeled modified solid lipid nanoparticles compared with unmodified nanoparticles. The cellular uptake study suggested that these nanoparticles could be a promising drug delivery system to enhance the uptake of antiviral drug by brain cells and it could be a suitable drug carrier system for the treatment of HIV.
Berkman, M S; Yazan, Y
An efficient sunscreen formulation shows good absorption in the relevant UV range. Efficacy also means that the UV absorber must be easily incorporated in any kind of formulation. In this study, a chemical absorber, octocrylene, and one of the most important physical blockers, zinc oxide, could be successfully incorporated into Solid Lipid Nanoparticle (SLN) systems which themselves have UV blocking potential similar to physical sunscreens, and remained stable for a period of 360 days while providing UVA and UVB protection. Crystalline structure related to the chemical nature of the solid lipid is a key factor to decide whether a sunscreening agent will be expelled or incorporated in the long-term and for a controlled optimization of active ingredient incorporation and loading, intensive characterization of the physical state of the lipid particles was highly essential. Thus, FT-IR, NMR, XRD and DSC analyses were performed and the results did not indicate stability problems. pH values of the SLN systems were found to be between 5.4-5.9 in all formulations which may be buffered by the skin. Transpore test results proved the UV blocking potential of the SLNs with not any active ingredient and the synergistic effects by the incorporation of molecular sunscreens. Therefore, concentration of molecular sunscreens in the formulations was decreased to 0.6%. UVA and UVB screening potentials of octocrylene and zinc oxide formulations were compared in the 290-400 nm wavelength region. Zinc oxide loaded SLN suspensions were found to be more effective in the UVA region while octocrylene loaded ones performed better in the UVB region.
Chen, Ying-Chen; Liu, Der-Zen; Liu, Jun-Jen; Chang, Tsung-Wei; Ho, Hsiu-O; Sheu, Ming-Thau
To resolve problems of long treatment durations and frequent administration of the antifungal agent terbinafine (TB), solid lipid nanoparticles (SLNs) with the ability to load lipophilic drugs and nanosize were developed. The SLNs were manufactured by a microemulsion technique in which glyceryl monostearate (GMS), glyceryl behenate (Compritol® 888; Gattefossé), and glyceryl palmitostearate (Precirol® ATO 5; Gattefossé) were used as the solid lipid phases, Tween® and Cremophor® series as the surfactants, and propylene glycol as the cosurfactant to construct ternary phase diagrams. The skin of nude mice was used as a barrier membrane, and penetration levels of TB of the designed formulations and a commercial product, Lamisil® Once™ (Novartis Pharmaceuticals), in the stratum corneum (SC), viable epidermis, and dermis were measured; particle sizes were determined as an indicator of stability. The optimal SLN system contained a <5% lipid phase and >50% water phase. The addition of ethanol or etchants had no significant effect on enhancing the amount of TB that penetrated the skin layers, but it was enhanced by increasing the percentage of the lipid phase. Furthermore, the combination of GMS and Compritol® 888 was able to increase the stable amount of TB that penetrated all skin layers. For the ACP1-GM1 (4% lipid phase; Compritol® 888: GMS of 1:1) formulation, the amount of TB that penetrated the SC was similar to that of Lamisil® Once™, whereas the amount of TB of the dermis was higher than that of Lamisil® Once™ at 12 hours, and it was almost the same as that of Lamisil® Once™ at 24 hours. It was concluded that the application of ACP1-GM1 for 12 hours might have an efficacy comparable to that of Lamisil® Once™ for 24 hours, which would resolve the practical problem of the longer administration period that is necessary for Lamisil® Once™. PMID:22923986
Kim, Jin-Ho; Kim, Youngwook; Bae, Ki Hyun; Park, Tae Gwan; Lee, Jung Hee; Park, Keunchil
Water-insoluble anticancer drugs, including paclitaxel, present severe clinical side effects when administered to patients, primarily associated with the toxicity of reagents used to solubilize the drugs. In efforts to develop alternative formulations of water-insoluble anticancer drugs suitable for intravenous administration, we developed biocompatible anticancer therapeutic solid lipid nanoparticles (SLNs), mimicking the structure and composition of natural particles, low-density lipoproteins (LDLs), for tumor-targeted delivery of paclitaxel. These therapeutic nanoparticles contained water-insoluble paclitaxel in the core with tumor-targeting ligand covalently conjugated on the polyethylene glycol (PEG)-modified surface (targeted PtSLNs). In preclinical human cancer xenograft mouse model studies, the paclitaxel-containing tumor-targeting SLNs exhibited pronounced in vivo stability and enhanced biocompatibility. Furthermore, these SLNs had superior antitumor activity to in-class nanoparticular therapeutics in clinical use (Taxol and Genexol-PM) and yielded long-term complete responses. The in vivo targeted antitumor activities of the SLN formulations in a mouse tumor model suggest that LDL-mimetic SLN formulations can be utilized as a biocompatible, tumor-targeting platform for the delivery of various anticancer therapeutics.
Albuquerque, João; Moura, Catarina Costa; Sarmento, Bruno; Reis, Salette
Rheumatoid arthritis (RA) is the most common joint-related autoimmune disease and one of the most severe. Despite intensive investigation, the RA inflammatory process remains largely unknown and finding effective and long lasting therapies that specifically target RA is a challenging task. This study proposes a different approach for RA therapy, taking advantage of the new emerging field of nanomedicine to develop a targeted theranostic system for intravenous administration, using solid lipid nanoparticles (SLN), a biocompatible and biodegradable colloidal delivery system, surface-functionalized with an anti-CD64 antibody that specifically targets macrophages in RA. Methotrexate (MTX) and superparamagnetic iron oxide nanoparticles (SPIONs) were co-encapsulated inside the SLNs to be used as therapeutic and imaging agents, respectively. All the formulations presented sizes under 250 nm and zeta potential values lower than -16 mV, suitable characteristics for intravenous administration. Transmission electron microscopy (TEM) photographs indicated that the SPIONs were encapsulated inside the SLN matrix and MTX association efficiency values were higher than 98%. In vitro studies, using THP-1 cells, demonstrated that all formulations presented low cytotoxicity at concentrations lower than 500 μg/mL. It was proven that the proposed NPs were not cytotoxic, that both a therapeutic and imaging agent could be co-encapsulated and that the SLN could be functionalized for a potential future application such as anti-body specific targeting. The proposed formulations are, therefore, promising candidates for future theranostic applications.
Abrishami, Majid; Vakili Ahrari Roodi, Mohammad
Purpose. In order to improve the drug availability after intravitreal administration, solid lipid nanoparticles (SLNs) containing diclofenac were prepared. Methods. In this experimental study, 18 albino rabbits were included. In right and left eyes of all rabbits, SLNs containing diclofenac and commercial form of diclofenac (0.3 mg drug) were intravitreally injected, respectively. One, four, twelve, twenty-four, and forty-eight hours after injection, vitreous and aqueous humor samples were obtained in all cases. Then, the concentration of diclofenac sodium was evaluated in all samples. Results. Size of nanoparticles was around 170 nm after preparation. Drug concentration in eyes injected with SLNs was significantly higher than left eyes injected with commercial formulation up to 4 hours after intravitreal injection (p < 0.05). Diclofenac was quantified in samples up to 48 hours after intraocular injection. Four hours after intravitreal injection, the concentration of diclofenac in vitreous and aqueous humor of eyes receiving SLNs was, respectively, 2.5 and 6.5 times higher than eyes injected with commercial form of drug. Conclusions. Here, we demonstrate the potential of SLNs as a carrier of diclofenac for intraocular injection in order to prevent the systemic effects of the drug, increase the injection intervals, and improve the patient compliance. PMID:27803815
Hansraj, Girotra Priti; Singh, Shailendra Kumar; Kumar, Pawan
The objective of the present investigation was to prepare chitosan solid lipid nanoparticles (SLN), containing sumatriptan succinate using solvent injection method and to optimize the formulations for brain targeting potential. The formulation optimization was performed using three factor two level full factorial design so as to minimize the particle size and zeta potential, maximize the entrapment efficiency as well as maximize the concentration of drug in brain with maximized brain/plasma ratio of the drug. The particle size, zeta potential and entrapment efficiency for all the batches were in the range of 192-301.4nm, 30.2-51.4mV and 76.3-91.1% respectively. The optimized formulation showed a 4.54-fold increase in brain/blood ratio of drug after 2h of drug administration in male Wistar rats. The optimized nanoparticles were characterized by FT-IR spectroscopy, DSC, TGA, powder X-ray diffraction study and TEM analysis. It could be elucidated from the experimental in vivo and behavioral studies that the formulations successfully crossed the blood brain barrier and significantly exhibited its anti-migraine activity. Present investigation indicated that the hydrophilic drug sumatriptan succinate, loaded in chitosan SLN, can be successfully targeted to brain via oral delivery and thus present an effective approach for the therapeutic management of migraine.
Aboud, Heba M; El Komy, Mohammed H; Ali, Adel A; El Menshawe, Shahira F; Abd Elbary, Ahmed
Carvedilol, a beta-adrenergic blocker, suffers from poor systemic availability (25%) due to first-pass metabolism. The aim of this work was to improve carvedilol bioavailability through developing carvedilol-loaded solid lipid nanoparticles (SLNs) for nasal administration. SLNs were prepared by emulsion/solvent evaporation method. A 2(3) factorial design was employed with lipid type (Compritol or Precirol), surfactant (1 or 2% w/v poloxamer 188), and co-surfactant (0.25 or 0.5% w/v lecithin) concentrations as independent variables, while entrapment efficiency (EE%), particle size, and amount of carvedilol permeated/unit area in 24 h (Q 24) were the dependent variables. Regression analysis was performed to identify the optimum formulation conditions. The in vivo behavior was evaluated in rabbits comparing the bioavailability of carvedilol after intravenous, nasal, and oral administration. The results revealed high drug EE% ranging from 68 to 87.62%. Carvedilol-loaded SLNs showed a spherical shape with an enriched core drug loading pattern having a particle size in the range of 66 to 352 nm. The developed SLNs exhibited significant high amounts of carvedilol permeated through the nasal mucosa as confirmed by confocal laser scanning microscopy. The in vivo pharmacokinetic study revealed that the absolute bioavailability of the optimized intranasal SLNs (50.63%) was significantly higher than oral carvedilol formulation (24.11%). Hence, we conclude that our developed SLNs represent a promising carrier for the nasal delivery of carvedilol.
de Jesus, Marcelo B; Zuhorn, Inge S
Solid lipid nanoparticles (SLNs) have been proposed in the 1990s as appropriate drug delivery systems, and ever since they have been applied in a wide variety of cosmetic and pharmaceutical applications. In addition, SLNs are considered suitable alternatives as carriers in gene delivery. Although important advances have been made in this particular field, fundamental knowledge of the underlying mechanisms of SLN-mediated gene delivery is conspicuously lacking, an imperative requirement in efforts aimed at further improving their efficiency. Here, we address recent advances in the use of SLNs as platform for delivery of nucleic acids as therapeutic agents. In addition, we will discuss available technology for conveniently producing SLNs. In particular, we will focus on underlying molecular mechanisms by which SLNs and nucleic acids assemble into complexes and how the nucleic acid cargo may be released intracellularly. In discussing underlying mechanisms, we will, when appropriate, refer to analogous studies carried out with systems based on cationic lipids and polymers, that have proven useful in the assessment of structure-function relationships. Finally, we will give suggestions for improving SLN-based gene delivery systems, by pointing to alternative methods for SLNplex assembly, focusing on the realization of a sustained nucleic acid release.
Geetha, T; Kapila, Meenakshi; Prakash, Om; Deol, Parneet Kaur; Kakkar, Vandita; Kaur, Indu Pal
Abstract Role of reactive oxygen species (ROS) in skin carcinogenesis is well documented. Natural molecules, like sesamol, with marked antioxidant potential can be useful in combating skin cancers. In vitro antiproliferative (using MTT assay) and DNA fragmentation studies in HL 60 cell lines, confirmed the apoptotic nature of sesamol. However, it showed a significant flux across the mice skin upon topical application, such that its local availability in skin is limited. Former is attributed mainly to its properties like small size, low molecular weight (138.28), and a sufficient lipid and water solubility (log P 1.29; solubility 38.8 mg/ml). To achieve its maximum epicutaneous delivery, packaging it into a suitable carrier system is thus indicated. Sesamol-loaded solid lipid nanoparticles (S-SLN) were thus prepared with particle size of 127.9 nm (PI: 0.256) and entrapment efficiency of 88.21%. Topical application of S-SLN in a cream base indicated significant retention in the skin with minimal flux across skin as confirmed by the in-vivo skin retention and ex-vivo skin permeation studies. In vivo anticancer studies performed on TPA-induced and benzo(a)pyrene initiated tumour production (ROS mediated) in mouse epidermis showed the normalization (in histology studies) of skin cancers post their induction, upon treatment with S-SLN.
Paranjpe, M; Finke, J H; Richter, C; Gothsch, T; Kwade, A; Büttgenbach, S; Müller-Goymann, C C
For the development of any colloidal system, thorough characterization is extremely essential. This article discusses the physicochemical characterization of sildenafil-loaded solid lipid nanoparticle dispersions (SLN) including stability analysis over 6 months time period for possible pulmonary administration for the treatment of pulmonary arterial hypertension (PAH). SLN consisting of phospholipid and triglycerides were manufactured using a novel microchannel homogenization method. These sildenafil-loaded SLN were then subjected to physicochemical characterization namely, particle size and distribution over shelf life, differential scanning calorimetry (DSC), wide angle X-ray diffraction (WAXD) and analysis of nebulization performance of these SLN by the means of next generation impactor (NGI). Additionally, the morphology of nebulized particles was assessed by transmission electron microscopy using negative staining technique. The solubility of sildenafil citrate and base in the lipid matrix was determined and was 0.1% w/w and 1% w/w, respectively. From the particle size measurements, it was observed that SLN without sildenafil demonstrated consistent particle sizes over 6 months. For the sildenafil-loaded SLN, increased particle sizes were found after manufacturing and further increased within weeks. From WAXD studies, after 6 months high intensity reflections corresponding to the stable β modification were observed. From DSC results, the peak minimum temperatures increased upon storage, hinting at a transformation to the stable β modification of triglycerides in the case of sildenafil-loaded SLN. Hence, it can be concluded that even small drug concentration influences particle size and stability.
Patel, Ravi R; Chaurasia, Sundeep; Khan, Gayasuddin; Chaubey, Pramila; Kumar, Nagendra; Mishra, Brahmeshwar
Cromolyn sodium (CS), a mast cell stabiliser, is widely employed for the prevention and treatment of allergic conditions. However, high hydrophilicity and poor oral permeability hinder its oral clinical translation. Here, solid lipid nanoparticles (SLNs) have been developed for the purpose of oral bioavailability enhancement. The CS-SLNs were engineered by double emulsification method (W1/O/W2) and optimised by using Box-Behnken experimental design. The surface and solid-state characterisations revealed the presence of CS in an amorphous form without any interactions inside the spherical-shaped SLNs. The in-vitro release study showed an extended release up to 24 hr by diffusion controlled process. Ex-vivo and in-vivo intestinal permeation study showed ∼2.96-fold increase in permeability of CS by presentation as SLNs (p < 0.05). Further, in-vivo pharmacokinetic study exhibited ∼2.86-fold enhancements in oral bioavailability of CS by encapsulating inside SLNs, which clearly indicate that SLNs can serve as the potential therapeutic carrier system for oral delivery of CS.
Negi, Jeetendra Singh; Chattopadhyay, Pronobesh; Sharma, Ashok Kumar; Ram, Veerma
Solid lipid nanoparticles (SLNs) of poor orally bioavailable drug lopinavir were prepared using hot self nano-emulsification (SNE) technique. Hot isotropic mixture of stearic acid, poloxamer and polyethylene glycol was spontaneously self nano-emulsify in hot water and SLNs were formed with subsequent rapid cooling. Self nano-emulsification ability of stearic acid, poloxamer and polyethylene glycol mixture was assessed by ternary phase diagram study. Optimized SLNs were having particle size of 180.6 ± 2.32 nm (PDI=0.133 ± 0.001), 91.5 ± 1.3% entrapment efficiency and zeta potential of -13.4 ± 0.56 mV. SLNs were evaluated by transmission electron microscopy (TEM) and atomic force microscopy (AFM) for morphological study. Further, Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) of SLNs were also performed for checking solid state characterization. Higher oral bioavailability was found for lopinavir loaded SLNs in comparison to bulk lopinavir due to higher lymphatic drug transport (p<0.05). Results indicate that SLNs of higher fatty acids can be successfully prepared by hot SNE technique.
Nazemiyeh, Elham; Eskandani, Morteza; Sheikhloie, Hossein; Nazemiyeh, Hossein
Purpose: Lycopene belongs to the carotenoids that shows good pharmacological properties including antioxidant, anti-inflammatory and anticancer. However, as a result of very low aqueous solubility, it has a limited systemic absorption, following oral administration. Methods: Here, we prepared a stable lycopene-loaded solid lipid nanoparticles using Precirol® ATO5, Compritol 888 ATO and myristic acid by hot homogenization method with some modification. The size and morphological characteristics of nanoparticles were evaluated using Scanning Electron Microscopy (SEM). Moreover, zeta potential and dispersity index (DI) were measured using zeta sizer. In addition, encapsulation efficiency (EE%), drug loading (DL) and cumulative drug release were quantified. Results: The results showed that the size and DI of particles was generally smaller in the case of SLNs prepared with precirol when compared to SLNs prepared with compritol. Scanning electron microscopy (SEM) and particle size analyses showed spherical SLNs (125 ± 3.89 nm), monodispersed distribution, and zeta potential of −10.06 ± 0.08 mV. High EE (98.4 ± 0.5 %) and DL (44.8 ± 0.46 mg/g) were achieved in the case of nanoparticles prepared by precirol. The stability study of the lycopene-SLNs in aqueous medium (4 °C) was showed that after 2 months there is no significant differences seen in size and DI compared with the fresh formulation. Conclusion: Conclusively, in this investigation we prepared a stable lycopene-SLNs with good physicochemical characteristic which candidate it for the future in vivo trials in nutraceutical industries. PMID:27478786
Mulik, Rohit S; Mönkkönen, Jukka; Juvonen, Risto O; Mahadik, Kakasaheb R; Paradkar, Anant R
Broad spectrum therapeutic potential of curcumin is usually hampered by its photodegradation and low bioavailability. Present investigation was designed with an objective to develop transferrin-mediated solid lipid nanoparticles (Tf-C-SLN) resistant to the photostability and capable of enhancing the bioavailability by targeted drug delivery to elicit anticancer activity against SH-SY5Y neuroblastoma cells in vitro. Hot homogenization method was used for the formulation of Tf-C-SLN and evaluated physicochemically using parameters such as, size, zeta potential, entrapment efficiency and photostability, transmission electron microscopy (TEM), nuclear magnetic resonance (NMR), differential scanning colorimetry (DSC), and in vitro release study. In vitro cytotoxicity and apoptosis investigations were performed using microplate analysis and flow cytometry techniques. The physicochemical characterization confirmed the suitability of formulation method and various parameters therein. TEM investigation revealed the spherical morphology while NMR and DSC study confirmed the entrapment of curcumin inside the nanoparticles. The cytotoxicity, reactive oxygen species, and cell uptake were found to be increased considerably with Tf-C-SLN compared with curcumin-solubilized surfactant solution, and curcumin-loaded SLN (C-SLN) suggesting the targeting effect. AnnexinV-FITC/PI double staining, DNA analysis, caspase detection, and reduced mitochondrial potential confirmed the induction of apoptosis with nanoparticle treatment. Enhanced anticancer activity with Tf-C-SLN compared with curcumin-solubilized surfactant solution and C-SLN was observed from flow cytometry investigations with apoptosis being the major underlying mechanism. The in vitro observations of our investigation are very compelling and concrete to advocate the potential of Tf-C-SLN in enhancing the anticancer effect of curcumin against neuroblastoma in vivo and possible clinical applications.
Jo, Yeon-Ji; Choi, Mi-Jung
This study was performed to investigate the effect of palm or coconut solid lipid nanoparticles (PO-SLNs or CO-SLNs) on growth of Lactobacillus plantarum (L. plantarum) in milk during storage period. The PO or CO (0.1% or 1.0%) was dispersed both in distilled water (DW) and ultra high temperature milk (UHTM), and subsequently emulsified with Tween® 80 by ultrasonication (30% power, 2 min). Increase in particle size and encapsulation efficiency (EE%) in DW was observed with an increase in oil concentration, whereas a decrease in ζ-potential of SLNs was noted with an increment in oil concentration. Moreover, the CO-SLNs exhibited relatively smaller particle size and higher EE% than PO-SLNs. The CO-SLNs were found to be more stable than PO-SLNs. Higher lipid oxidation of PO or CO-SLNs in UHTM was observed during the storage test, when compared to PO or CO-SLNs in DW. However, there was no remarkable difference in lipid oxidation during storage period (p>0.05). In the growth test, the viability of L. plantarum in control (without PO or CO-SLNs in DW) exhibited a dramatic decrease with increasing storage period. In addition, viability of L. plantarum of PO or CO-SLNs in UHTM was higher than that of SLNs in DW. Based on the present study, production of SLNs containing PO or CO in UHTM is proposed, which can be used in lactobacilli fortified beverages in food industry. PMID:26761828
Jo, Yeon-Ji; Choi, Mi-Jung; Kwon, Yun-Joong
This study was performed to investigate the effect of palm or coconut solid lipid nanoparticles (PO-SLNs or CO-SLNs) on growth of Lactobacillus plantarum (L. plantarum) in milk during storage period. The PO or CO (0.1% or 1.0%) was dispersed both in distilled water (DW) and ultra high temperature milk (UHTM), and subsequently emulsified with Tween(®) 80 by ultrasonication (30% power, 2 min). Increase in particle size and encapsulation efficiency (EE%) in DW was observed with an increase in oil concentration, whereas a decrease in ζ-potential of SLNs was noted with an increment in oil concentration. Moreover, the CO-SLNs exhibited relatively smaller particle size and higher EE% than PO-SLNs. The CO-SLNs were found to be more stable than PO-SLNs. Higher lipid oxidation of PO or CO-SLNs in UHTM was observed during the storage test, when compared to PO or CO-SLNs in DW. However, there was no remarkable difference in lipid oxidation during storage period (p>0.05). In the growth test, the viability of L. plantarum in control (without PO or CO-SLNs in DW) exhibited a dramatic decrease with increasing storage period. In addition, viability of L. plantarum of PO or CO-SLNs in UHTM was higher than that of SLNs in DW. Based on the present study, production of SLNs containing PO or CO in UHTM is proposed, which can be used in lactobacilli fortified beverages in food industry.
Vijayakumar, Ajay; Baskaran, Rengarajan; Jang, Young Soo; Oh, Seung Hyun; Yoo, Bong Kyu
The objective of this study was to formulate and characterize properties of solid lipid nanoparticle (SLN) dispersion containing quercetin. SLN was prepared by ultrasonication method using tripalmitin and lecithin as lipid core and then the surface was coated with chitosan. Entrapment efficiency was greater than 99%, and mean particle size of SLN was 110.7 ± 1.97 nm with significant increase in the coated SLN (c-SLN). Zeta potential was proportionally increased and reached plateau at 5% of chitosan coating with respect to tripalmitin. Differential scanning calorimetry showed disappearance of endothermic peak of quercetin in SLNs, indicating conversion of crystalline state to amorphous state. FTIR study of SLNs showed no change in the spectrum of quercetin, which indicates that the lipid and chitosan were not incompatible with quercetin. When coating amount was greater than 2.5% of tripalmitin, particle size and zeta potential were very stable even at 40°C up to 90 days. All SLN dispersions showed significantly faster release profile compared to pure quercetin powder. At pH 7.0, the release rate was increased in proportion to the coating amount. Interestingly, at pH 3.0, chitosan coating of 5.0% or greater decreased the rate. Cellular uptake of quercetin was performed using Caco-2 cells and showed that all SLN dispersions were significantly better than quercetin dispersed in distilled water. However, cellular uptake of quercetin from c-SLN was significantly lower than that from uncoated SLN.
Girotra, Priti; Singh, Shailendra Kumar
The present investigation aimed at development of brain-targeted rizatriptan benzoate-loaded solid lipid nanoparticles (RB-SLNs) by design of experiment, for improvement of its anti-migraine potential. Several formulation variables affecting the fabrication of RB-SLNs were screened using the Plackett-Burman design (PBD). The PBD results demonstrated lipid (Precirol® ATO 5) concentration, co-surfactant (Phospholipon® 90 H) concentration and temperature of lipid melt to be the critical variables, having a significant effect on the achievement of minimum particle size, maximum entrapment efficiency coupled with sustained drug release. The interactions between these formulation parameters and the variability between the batches were further explored employing the Box-Behnken design (BBD). The BBD results were validated by fabricating the suggested optimized solution, which yielded 220.4 ± 2.3 nm particle size with a sufficiently high entrapment efficiency of 71.8 ± 1.9% and 45.9 ± 2.7% cumulative drug release in 8 h. The optimized formulation was, thereafter, characterized by FTIR spectroscopy, wide angle XRD, thermal analysis and TEM imaging technique. The in vivo studies revealed the brain uptake potential of optimized RB-SLNs to be 18.43-folds higher with respect to the pure drug in its free form, post 2 h of oral drug administration. The significant anti-migraine efficacy of RB-SLNs was corroborated through the pharmacodynamic studies on adult male Swiss albino mice. The results hence explicate that RB-SLNs have distinctly improved brain target ability and offer an apt approach for the efficient therapeutic management of migraine.
Clares, Beatriz; Calpena, Ana C; Parra, Alexander; Abrego, Guadalupe; Alvarado, Helen; Fangueiro, Joana F; Souto, Eliana B
The aim of this study was to develop biocompatible lipid-based nanocarriers for retinyl palmitate (RP) to improve its skin delivery, photostability and biocompatibility, and to avoid undesirable topical side effects. RP loaded nanoemulsions (NEs), liposomes (LPs) and solid lipid nanoparticles (SLNs) were characterized in terms of size, surface electrical charge, pH, drug encapsulation efficiency and morphology. Spherical-shaped nanocarriers with a negatively charged surface (>|40|mV) and mean size lower than 275 nm were produced with adequate skin compatibility. The rheological properties showed that aqueous dispersions of SLNs followed a non-Newtonian behavior, pseudoplastic fluid adjusted to Herschel-Bulkley equation, whereas LPs and NEs exhibited a Newtonian behavior. SLNs offered significantly better photoprotection than LPs and NEs for RP. The cumulative amount of drug permeated through human skin at the end of 38 h was 6.67 ± 1.58 μg, 4.36 ± 0.21 μg and 3.64 ± 0.28 μg for NEs, LPs and SLNs, respectively. NEs flux was significantly higher than SLNs and LPs: NEs (0.37 ± 0.12 μg/h) > LPs (0.15 ± 0.09 μg/h) > SLNs (0.10 ± 0.05 μg/h). LPs offered significant higher skin retention than NEs and SLNs. Finally, even though all developed nanocarriers were found to be biocompatible, according to histological studies, NE was the system that most disrupted the skin. These encouraging findings can guide in proper selection of topical carriers among the diversity of available lipid-based nanocarriers, especially when a dermatologic or cosmetic purpose is desired.
Ghanbarzadeh, Saeed; Hariri, Reza; Kouhsoltani, Maryam; Shokri, Javad; Javadzadeh, Yousef; Hamishehkar, Hamed
Hydroquinone (HQ), a well-known anti-hyperpigmentation agent suffers from (a) instability due to rapid oxidation, (b) insufficient skin penetration because of hydrophilic structure, and (c) severe side effects as a results of systemic absorption. This study aimed to load HQ into solid lipid nanoparticles (SLNs) to overcome the mentioned drawbacks for the efficient treatment of hyperpigmentation. The optimized SLN formulation was prepared by hot melt homogenization method and fully characterized by various techniques. The ability of SLNs in dermal delivery of HQ was assessed through the excised rat skin. The optimized HQ-loaded SLNs (particle size of 86 nm, encapsulation efficiency% of 89.5% and loading capacity% of 11.2%) exhibited a good physicochemical stability during a period of five months. XRD and DSC results showed that HQ was dispersed in an amorphous state, confirming uniform drug dispersion in the SLNs structure and embedment of drug in the solid lipid matrix. In vitro penetration studies showed almost 3 times higher drug accumulation in the skin and 6.5 times lower drug entrance to receiving compartment of Franz diffusion cell from HQ-loaded SLN hydrogel compared with HQ Carbopol made hydrogel. These results indicated the better HQ localization in the skin and its lower systemic absorption. It was concluded that SLN is a promising colloidal drug carrier for topical administration of HQ in the treatment of hyperpigmentation due to suitable HQ loading value in spite of its hydrophilic structure, high stability against oxidation and appropriate skin penetration along with the low systemic absorption.
Hosny, Khaled Mohamed
Treatment of osteoporosis with alendronate sodium has several challenges. The first challenge is the low bioavailability. The second main challenge is side effects, which include oesophageal ulceration. The aim of this research was to reformulate alendronate sodium as enteric coated solid lipid nanoparticles in order to enhance its bioavailability, and preventing the free alendronate sodium from coming into direct contact with the gastrointestinal mucosa, and thereby reducing the possibility of side effects. Enteric coated solid lipid nanoparticles were prepared according to the Box-Behnken design employing Design expert® software, and characterized for size, morphology, and entrapment efficiency. The optimized formula was coated with an Eudragit S100 and evaluated for drug release in acidic and basic media, stability studies and pharmacokinetic evaluations on rabbits. The results indicated that, using Derringer's desirability functional tool for optimization, the highest entrapment efficiency value of 74.3% and the smallest size value of 98 nm were predicted under optimum conditions with a desirability value of 0.917. The optimized nanoparticles released alendronate sodium only at an alkaline pH. The pharmacokinetic evaluation revealed that alendronate sodium bioavailability was enhanced by more than 7.4-fold in rabbits. In conclusion, enteric coated solid lipid nanoparticles is a promising formula for the delivery of alendronate sodium, eliminating its oesophageal side effects and enhancing its bioavailability. PMID:27148747
Akbari, Jafar; Saeedi, Majid; Morteza-Semnani, Katayoun; Rostamkalaei, Seyyed Sohrab; Asadi, Masoumeh; Asare-Addo, Kofi; Nokhodchi, Ali
The aim of the current investigation was to produce naproxen solid lipid nanoparticles (Nap-SLNs) by the ultrasonication method to improve its skin permeation and also to investigate the influence of Hydrophilic-lipophilic balance (HLB) changes on nanoparticles properties. The properties of obtained SLNs loaded with naproxen were characterized by photon correlation spectroscopy (PCS), transmission electron microscopy (TEM) and differential scanning calorimetry (DSC). FT-IR was also used to investigate any interaction between naproxen and the excipients used at the molecular level during the preparation of the SLNs. The performance of the formulations was investigated in terms of skin permeation and also the retention of the drug by the skin. It was found that generally, with increasing the lipid concentration, the average particle size and polydispersity index (PDI) of SLNs increased from 94.257±4.852nm to 143.90±2.685nm and from 0.293±0.037 to 0.525±0.038 respectively. The results also showed that a reduction in the HLB resulted in an increase in the PDI, particle size, zeta potential and entrapment efficiency (EE%). DSC showed that the naproxen encapsulated in the SLNs was in its amorphous form. The peaks of prominent functional groups of naproxen were found in the FT-IR spectra of naproxen-SLN, which confirmed the entrapment of naproxen in the lipid matrix. FT-IR results also ruled out any chemical interaction between drug and the chemicals used in the preparation of SLNs. The amount of naproxen detected in the receptor chamber at all the sampling times for the reference formulation (naproxen solution containing all surfactants at pH 7.4) was higher than that of the Nap-SLN8 formulation. Nap-SLN8 showed an increase in the concentration of naproxen in the skin layer with less systemic absorption. This indicates that most of the drug in Nap-SLN8 remains in the skin which can reduce the side effect of systemic absorption of the drug and increases the
Ying, Bo; Campbell, Robert B.
Highlights: • siRNA-lipid nanoparticles are solid particles not lipid bilayers with aqueous core. • High, but not low, PEG content can prevent nanoparticle encapsulation of siRNA. • PEG reduces cellular toxicity of cationic nanoparticles in vitro. • PEG reduces zeta potential while improving gene silencing of siRNA nanoparticles. • Kinesin spindle protein can be an effective target for tumor vascular targeting. - Abstract: The ideal siRNA delivery system should selectively deliver the construct to the target cell, avoid enzymatic degradation, and evade uptake by phagocytes. In the present study, we evaluated the importance of polyethylene glycol (PEG) on lipid-based carrier systems for encapsulating, and delivering, siRNA to tumor vessels using cellular models. Lipid nanoparticles containing different percentage of PEG were evaluated based on their physical chemical properties, density compared to water, siRNA encapsulation, toxicity, targeting efficiency and gene silencing in vitro. siRNA can be efficiently loaded into lipid nanoparticles (LNPs) when DOTAP is included in the formulation mixture. However, the total amount encapsulated decreased with increase in PEG content. In the presence of siRNA, the final formulations contained a mixed population of particles based on density. The major population which contains the majority of siRNA exhibited a density of 4% glucose, and the minor fraction associated with a decreased amount of siRNA had a density less than PBS. The inclusion of 10 mol% PEG resulted in a greater amount of siRNA associated with the minor fraction. Finally, when kinesin spindle protein (KSP) siRNA was encapsulated in lipid nanoparticles containing a modest amount of PEG, the proliferation of endothelial cells was inhibited due to the efficient knock down of KSP mRNA. The presence of siRNA resulted in the formation of solid lipid nanoparticles when prepared using the thin film and hydration method. LNPs with a relatively modest amount of
Hathout, Rania M; Metwally, Abdelkader A
This study represents one of the series applying computer-oriented processes and tools in digging for information, analysing data and finally extracting correlations and meaningful outcomes. In this context, binding energies could be used to model and predict the mass of loaded drugs in solid lipid nanoparticles after molecular docking of literature-gathered drugs using MOE® software package on molecularly simulated tripalmitin matrices using GROMACS®. Consequently, Gaussian processes as a supervised machine learning artificial intelligence technique were used to correlate the drugs' descriptors (e.g. M.W., xLogP, TPSA and fragment complexity) with their molecular docking binding energies. Lower percentage bias was obtained compared to previous studies which allows the accurate estimation of the loaded mass of any drug in the investigated solid lipid nanoparticles by just projecting its chemical structure to its main features (descriptors).
Jose, S; Anju, S S; Cinu, T A; Aleykutty, N A; Thomas, S; Souto, E B
Resveratrol is a potent anticancer. However, because of its low half-life (<0.25 h) the molecule is difficult to achieve the therapeutic concentration at the site of action. The aim of this work was to check the brain targeting ability of glyceryl behenate-based solid lipid nanoparticles (SLN) for resveratrol. SLN were prepared by solvent evaporation technique employing high speed homogenization followed by ultrasonication. SLN were designed at varying drug-lipid ratios (1:5, 1:9, 1:10, 1:11, 1:12 and 1:15) using Tween 80 or a combination of Tween 80 and polyvinyl alcohol (PVA) as surfactants. The mean particle size and zeta potential of the optimized formulation (drug-lipid ratio of 1:10) were 248.30 ± 3.80nm and -25.49 ± 0.49mV, respectively. The particle size and the encapsulation efficiency (EE) increased when varying the drug-lipid ratio from 1:5 to 1:15. Scanning electron microscopic (SEM) analysis showed that SLN were spherical in shape and had a smooth surface. The X-ray diffraction (XRD) and differential scanning calorimetry (DSC) analyses revealed that the matrix of drug-loaded SLN was in disordered crystalline phase. The in vitro release study in phosphate buffer pH 7.4 followed a sustained release pattern. The drug release data was found to fit best into Higuchi kinetic model suggesting the diffusion controlled mechanism of drug release. The cytotoxicity assay (MAT) showed that SLN were equally effective (P<0.5) as free resveratrol, as an anti-tumor agent. The in vivo biodistribution study using Wistar rats demonstrated that SLN could significantly (P<0.001) increase the brain concentration of resveratrol (17.28 ± 0.6344 μg/g) as compared to free resveratrol (3.45 ± 0.3961 μg/g). The results showed that our resveratrol-loaded SLN serve as promising therapeutic systems to treat neoplastic diseases located in the brain tissue.
Dudhipala, Narendar; Veerabrahma, Kishan
Candesartan cilexetil (CC) is used in the treatment of hypertension and heart failure. It has poor aqueous solubility and low oral bioavailability. In this work, CC loaded solid lipid nanoparticles (CC-SLNs) were developed to improve the oral bioavailability. Components of the SLNs include either of trimyristin/tripalmitin/tristearin, and surfactants (Poloxamer 188 and egg lecithin E80). The CC loaded nanoparticles were prepared by hot homogenization followed by ultrasonication method. The physicochemical properties, morphology of CC-SLNs were characterized, the pharmacokinetic and pharmacodynamic behaviour of CC-SLNs were evaluated in rats. Stable CC-SLNs having a mean particle size of 180-220 nm with entrapment efficiency varying in between 91-96% were developed. The physical stability of optimized formulation was studied at refrigerated and room temperature for 3 months. Further, freeze drying was tried for improving the physical stability. DSC and XRD analyses indicated that the drug incorporated into SLN was in amorphous form but not in crystalline state. The SLN-morphology was found to be nearly spherical by electron microscopic studies. Pharmacokinetic results indicated that the oral bioavailability of CC was improved over 2.75-fold after incorporation into SLNs. Pharmacodynamic study of SLNs in hypertensive rats showed a decrease in systolic blood pressure for 48 h, while suspension showed a decrease in systolic blood pressure for only 2 h. Taken together, these effects are due to enhanced bioavailability coupled with sustained action of CC in SLN formulation. Thus, the results conclusively demonstrated the role of CC-SLNs for a significant enhancement in oral bioavailability along with improved pharmacodynamic effect.
Liu, Donghua; Liu, Chunxi; Zou, Weiwei; Zhang, Na
This study was aimed to prepare N3- O-toluyl-fluorouracil (TFu) loaded cationic solid lipid nanoparticles (TFu-SLNs) and evaluate the potential of a novel lipid-based drug delivery system to enhance the oral absorption of TFu. TFu-SLNs were prepared by the film dispersion-ultrasonication method, using hexadecyltrimethylammonium bromide as cationic tenside. The formulation and manufacture parameters were optimized concerning the drug encapsulation efficiency and the particle size. The in vitro release characteristics, in vivo pharmacokinetic properties and bioavailability, and in situ intestinal absorption features were investigated. The morphology of TFu-SLNs was approximately spherical and the mean particle size was 178.8 ± 9.99 nm; the zeta potential was +19.54 ± 0.32 mV. The mean entrapment efficiency and drug loading were 71.03 ± 1.19% and 3.57 ± 0.08%, respectively. The release behaviors of TFu from TFu-SLNs in PBS were fitted to the bioexponential model, while in artificial gastric juice, artificial intestinal juice and artificial gastric juice (2 h) followed by artificial intestinal juice (2-48 h) were fitted to the Weibull equation. The results of the pharmacokinetic studies in mice showed that the bioavailability of TFu-SLNs was significantly increased compared with that of the TFu suspensions after oral administration. The absorption of TFu-SLNs in intestine of rat was fitted to first-order kinetics with passive diffusion mechanism and the main segments of TFu-SLNs absorbed in intestine were duodenum and jejunum for the bioadhesion mediated by electrostatic interaction between the positively charged colloidal particles and the negatively charged mucosal surface. These results indicated that cationic SLNs would offer a promising delivery system for the facilitation of the bioavailability of poorly oral absorption drugs by enhancing the bioadhesion between the absorption mucosal surface and the drug carriers.
Xue, Mei; Yang, Ming-xing; Zhang, Wei; Li, Xiu-min; Gao, De-hong; Ou, Zhi-min; Li, Zhi-peng; Liu, Su-huan; Li, Xue-jun; Yang, Shu-yu
The high aqueous solubility, poor permeability, and absorption of berberine (BBR) result in its low plasma level after oral administration, which greatly limits its clinical application. BBR solid lipid nanoparticles (SLNs) were prepared to achieve improved bioavailability and prolonged effect. Developed SLNs showed homogeneous spherical shapes, small size (76.8 nm), zeta potential (7.87 mV), encapsulation efficiency (58%), and drug loading (4.2%). The power of X-ray diffraction combined with (1)H nuclear magnetic resonance spectroscopy was employed to analyze chemical functional groups and the microstructure of BBR-SLNs, and indicated that the drug was wrapped in a lipid carrier. Single dose (50 mg/kg) oral pharmacokinetic studies in rats showed significant improvement (P<0.05) in the peak plasma concentration, area under the curve, and variance of mean residence time of BBR-SLNs when compared to BBR alone (P<0.05), suggesting improved bioavailability. Furthermore, oral administration of both BBR and BBR-SLNs significantly suppressed body weight gain, fasting blood glucose levels, and homeostasis assessment of insulin resistance, and ameliorated impaired glucose tolerance and insulin tolerance in db/db diabetic mice. BBR-SLNs at high dose (100 mg/kg) showed more potent effects when compared to an equivalent dose of BBR. Morphologic analysis demonstrated that BBR-SLNs potentially promoted islet function and protected the islet from regeneration. In conclusion, our study demonstrates that by entrapping BBR into SLNs the absorption of BBR and its anti-diabetic action were effectively enhanced.
Goto, Patrícia L; Siqueira-Moura, Marigilson P; Tedesco, Antonio C
Cutaneous melanoma is the most aggressive skin cancer and is particularly resistant to current therapeutic approaches. Photodynamic therapy (PDT) is a well-established photoprocess that is employed to treat some cancers, including non-melanoma skin cancer. Aluminum chloride phthalocyanine (ClAlPc) is used as a photosensitizer in PDT; however, its high hydrophobicity hampers its photodynamic activity under physiological conditions. The aim of this study was to produce solid lipid nanoparticles (SLN) containing ClAlPc using the direct emulsification method. ClAlPc-loaded SLNs (ClAlPc/SLNs) were characterized according to their particle size and distribution, zeta potential, morphology, encapsulation efficiency, stability, and phototoxic action in vitro in B16-F10 melanoma cells. ClAlPc/SLN had a mean diameter between 100 and 200nm, homogeneous size distribution (polydispersity index <0.3), negative zeta potential, and spherical morphology. The encapsulation efficiency was approximately 100%. The lipid crystallinity was investigated using X-ray diffraction and differential scanning calorimetry and indicated that ClAlPc was integrated into the SLN matrix. The ClAlPc/SLN formulations maintained their physicochemical stability without expelling the drug over a 24-month period. Compared to free ClAlPc, ClAlPc/SLN exerted outstanding phototoxicity effects in vitro against melanoma cells. Therefore, our results demonstrated that the ClAlPc/SLN described in the current study has the potential for use in further preclinical and clinical trials in PDT for melanoma treatment.
Patro, Nagaraju M.; Devi, Kshama; Pai, Roopa S.; Suresh, Sarasija
We investigated the bioavailability, efficacy, and toxicity of doxorubicin-loaded solid lipid nanoparticles (DOX-SLNs) prepared by a simple modified double-emulsification method. A 3-factor, 3-level Box-Behnken statistical design was adopted in the optimization of DOX-SLN formulation considering dependent factors particle size and entrapment efficiency. Optimized SLN formulation composed of lipid (2 %) consisting of soya lecithin and Precirol ATO 5 (1:3) with Pluronic F68 (0.3 %) resulted in 217.36 ± 3.31 nm particle size and 59.45 ± 1.75 % entrapment efficiency. DOX-SLN exhibited significant enhancement ( p < 0.05) in bioavailability as compared with free DOX in Sprague-Dawley (SD) rats. DOX-SLN exhibited higher peak plasma concentration (6.761 ± 0.08 vs. 2.412 ± 0.04 μg/ml), increased AUC (61.368 ± 3.54 vs. 5.812 ± 0.49 μg/ml h), decreased clearance (36 ± 0.01 vs. 619 ± 0.005 mL/h kg), and volume of distribution (733 ± 0.092 vs. 2,064 ± 0.061 mL/kg) when compared to free DOX. The collective results of cardiac and kidney enzyme assay, antioxidant enzyme levels, hematological parameters, effect on body weight and tumor volume, tumor necrosis factor-α level, histopathological examination, and survival analysis confirmed the improved efficacy and safety profile of DOX-SLN in 7,12-dimethyl benzanthracene-induced breast cancer in SD rats.
Khare, Anubha; Singh, Inderbir; Pawar, Pravin; Grover, Kanchan
Voriconazole is a second-generation antifungal agent with excellent broad spectrum of antifungal activity commercially available for oral and intravenous administration. Systemic administration of voriconazole is associated with side effects including visual and hepatic abnormalities. This study assessed the feasibility of using solid lipid nanoparticles for ocular delivery of voriconazole adopting stearic acid as lipidic material, tween 80 as a stabilizer, and Carbopol 934 as controlled release agent and for increasing the precorneal residence time in eye. The systems were prepared using two different methods, that is, ultrasonication method and microemulsion technique. The results indicated that the larger particle size of SLNs was found with microemulsion technique (308 ± 3.52 nm to 343 ± 3.51) compared to SLN prepared with ultrasonication method (234 ± 3.52 nm to 288 ± 4.58 nm). The polydispersity index values were less than 0.3 for all formulations and zeta potential of the prepared formulations by these two methods varied from −22.71 ± 0.63 mV to −28.86 ± 0.58 mV. Powder X-ray diffraction and differential scanning calorimetry indicated decrease in crystallinity of drug. The in vitro release study and the SLN formulations prepared with ultrasonication method demonstrated sustained release up to 12 hours. This study demonstrated that SLN prepared by ultrasonication method is more suitable than microemulsion technique without causing any significant effect on corneal hydration level. PMID:27293896
Goindi, Shishu; Guleria, Ankita; Aggarwal, Nidhi
N-6-furfuryl adenine (N6FA) also known as "kinetin" is a biologically active natural phytochemical. It belongs to the category of cytokinins, the natural plant growth hormones that promote cell division and play role in cell differentiation. Overall, N6FA aids in increasing the plant's life span. Human cells also contain.small quantities of N6FA. Scientists are trying to understand its function in humans. N6FA is being investigated for its properties such as antiplatelet, antioxidant, antiproliferative and anti-aging effects on human cells. The aim of the present investigation was to prepare solid lipid nanoparticle (SLN) based topical formulations of N6FA and to evaluate its efficacy against ultraviolet (UV) radiation induced skin photodamage. SLNs were prepared by hot microemulsion technique and optimized for the type and concentration of lipid and surfactant(s). The optimized SLN formulation was characterized in terms of particle size, drug entrapment efficiency, zeta potential and pH; evaluated for stability, spreadability, ex-vivo skin permeation and photoprotective effects against UV induced skin damage. The cumulative amount of drug permeated through mice skin using SLNs was 3 folds higher than from conventional cream base. The results of biochemical and histopathological investigations of skin treated with N6FA loaded SLNs clearly demonstrated the efficacy of optimized formulation in preventing photodamage (lesions, ulcers and changes in skin integrity) due to chronic UV exposure. The effects were comparable with widely used marketed formulation, Garnier wrinkle lift anti-aging cream. Results suggested that N6FA incorporated into SLNs may provide therapeutic as well as cosmeceutical benefits.
Zariwala, M Gulrez; Elsaid, Naba; Jackson, Timothy L; Corral López, Francisco; Farnaud, Sebastien; Somavarapu, Satyanarayana; Renshaw, Derek
Iron (Fe) loaded solid lipid nanoparticles (SLN's) were formulated using stearic acid and iron absorption was evaluated in vitro using the cell line Caco-2 with intracellular ferritin formation as a marker of iron absorption. Iron loading was optimised at 1% Fe (w/w) lipid since an inverse relation was observed between initial iron concentration and SLN iron incorporation efficiency. Chitosan (Chi) was included to prepare chitosan coated SLN's. Particle size analysis revealed a sub-micron size range (300.3±31.75 nm to 495.1±80.42 nm), with chitosan containing particles having the largest dimensions. As expected, chitosan (0.1%, 0.2% and 0.4% w/v) conferred a net positive charge on the particle surface in a concentration dependent manner. For iron absorption experiments equal doses of Fe (20 μM) from selected formulations (SLN-FeA and SLN-Fe-ChiB) were added to Caco-2 cells and intracellular ferritin protein concentrations determined. Caco-2 iron absorption from SLN-FeA (583.98±40.83 ng/mg cell protein) and chitosan containing SLN-Fe-ChiB (642.77±29.37 ng/mg cell protein) were 13.42% and 24.9% greater than that from ferrous sulphate (FeSO4) reference (514.66±20.43 ng/mg cell protein) (p≤0.05). We demonstrate for the first time preparation, characterisation and superior iron absorption in vitro from SLN's, suggesting the potential of these formulations as a novel system for oral iron delivery.
Rute Neves, Ana; Fontes Queiroz, Joana; Weksler, Babette; Romero, Ignacio A.; Couraud, Pierre-Olivier; Reis, Salette
Nanotechnology can be an important tool to improve the permeability of some drugs for the blood-brain barrier. In this work we created a new system to enter the brain by functionalizing solid lipid nanoparticles with apolipoprotein E, aiming to enhance their binding to low-density lipoprotein receptors on the blood-brain barrier endothelial cells. Solid lipid nanoparticles were successfully functionalized with apolipoprotein E using two distinct strategies that took advantage of the strong interaction between biotin and avidin. Transmission electron microscopy images revealed spherical nanoparticles, and dynamic light scattering gave a Z-average under 200 nm, a polydispersity index below 0.2, and a zeta potential between -10 mV and -15 mV. The functionalization of solid lipid nanoparticles with apolipoprotein E was demonstrated by infrared spectroscopy and fluorimetric assays. In vitro cytotoxic effects were evaluated by MTT and LDH assays in the human cerebral microvascular endothelial cells (hCMEC/D3) cell line, a human blood-brain barrier model, and revealed no toxicity up to 1.5 mg ml-1 over 4 h of incubation. The brain permeability was evaluated in transwell devices with hCMEC/D3 monolayers, and a 1.5-fold increment in barrier transit was verified for functionalized nanoparticles when compared with non-functionalized ones. The results suggested that these novel apolipoprotein E-functionalized nanoparticles resulted in dynamic stable systems capable of being used for an improved and specialized brain delivery of drugs through the blood-brain barrier.
Berkman, M S; Yazan, Y
UV filters are traditionally classified as chemical absorbers and physical blockers depending on their mechanism of action. In this study, one of the most important chemical UVB absorber, octocrylene, was incorporated into Solid Lipid Nanoparticle (SLN) systems which themselves have UV blocking potential similar to physical blockers. Determination of octocrylene in the formulations was performed by HPLC (High Performance Liquid Chromatography) using a new validated method based on ICH harmonised tripartite guideline "validation of analytical procedures Q2(R1)". Determination and validation studies were carried out on a 4.6 x 250 mm, 5 microm C18 ACE column using an optimized mobile phase of acetonitrile:water (75:25, v/v) at a flow rate of 1.5 mL x min(-1). UV detection was performed at 210 nm and the column temperature was adjusted to 50 degrees C. Cyclosporine A was used as an internal standard (IS). The specified working range was derived from linearity studies and kept in the concentration range of 2.5 x -5.5 x 10(-5) M. Good correlation and accuracy were obtained. Limit of detection (LOD) and limit of quantitation (LOQ) values were determined to be 1.64 x 10(-6) M and 4.97 x 10-6 M, respectively. Octocrylene recovery % results of the SLN formulations stored at 25 degrees C, 4 degrees C and 40 degrees C for 360 days were investigated and compared to the freshly prepared samples.
Oliveira, Mariana S; Mussi, Samuel V; Gomes, Dawidson A; Yoshida, Maria Irene; Frezard, Frederic; Carregal, Virgínia M; Ferreira, Lucas A M
This work aimed to develop solid lipid nanoparticles (SLN) co-loaded with doxorubicin and α-tocopheryl succinate (TS), a succinic acid ester of α-tocopherol that exhibits anticancer actions, evaluating the influence of TS on drug encapsulation efficiency. The SLN were characterized for size, zeta potential, entrapment efficiency (EE), and drug release. Studies of in vitro anticancer activity were also conducted. The EE was significantly improved from 30 ± 1% to 96 ± 2% for SLN without and with TS at 0.4%, respectively. In contrast, a reduction in particle size from 298 ± 1 to 79 ± 1 nm was observed for SLN without and with TS respectively. The doxorubicin release data show that SLN provide a controlled drug release. The in vitro studies showed higher cytotoxicity for doxorubicin-TS-loaded SLN than for free doxorubicin in breast cancer cells. These findings suggest that TS-doxorubicin-loaded SLN is a promising alternative for the treatment of cancer.
Zhu, R. R.; Qin, L. L.; Wang, M.; Wu, S. M.; Wang, S. L.; Zhang, R.; Liu, Z. X.; Sun, X. Y.; Yao, S. D.
In an effort to develop an alternative formulation of podophyllotoxin suitable for drug release and delivery, podophyllotoxin-loaded solid lipid nanoparticles (PPT-SLNs) were constructed, characterized and examined for in vitro cytotoxicity and tumor inhibition. The SLNs were prepared by using a solvent emulsification-evaporation method, and their size was around 50 nm. TEM detection showed that the SLNs were homogeneous and spherical in shape, and differential scanning calorimetry (DSC) measurement revealed a new conformation of PPT-SLNs. An in vitro drug release study showed that PPT was released from the SLNs in a slow but time-dependent manner. Furthermore, the treatment of 293T and HeLa cells with PPT-SLNs demonstrated that PPT-SLNs were less toxic to normal cells and more effective in anti-tumor potency compared with unconjugated PPT. A colony forming efficiency assay showed an effective long-term cancer growth suppression of PPT-SLNs; in addition, they can also enhance the apoptotic and cellular uptake processes on tumor cells compared with PPT. These results collectively demonstrated that this SLN formulation has a potential application as an alternative delivery system for anti-tumor drugs.
Shah, Rohan M; Rajasekaran, Dhivya; Ludford-Menting, Mandy; Eldridge, Daniel S; Palombo, Enzo A; Harding, Ian H
Development of drug delivery systems, as much as the drug molecule itself, is an important consideration for improving drug absorption and bioavailability. The mechanisms by which drug carriers enter target cells can differ depending on their size, surface properties and components. Solid lipid nanoparticles (SLNs) have gained an increased attention in recent years and are the drug carriers of interest in this paper. They are known to breach the cell-membrane barrier and have been actively sought to transport biomolecules. Previous studies by our group, and also other groups, provided an extensive characterization of SLNs. However, few studies have investigated the uptake of SLNs and these have had limited mechanistic focus. The aim of this work was to investigate the pathway of uptake of SLNs by human epithelial cells i.e., lung A549 and cervical HeLa cells. To the best of our knowledge, this is first study that investigates the cellular uptake of SLNs by human epithelial cells. The mechanism of cellular uptake was deciphered using pharmacologic inhibitors (sucrose, potassium-free buffer, filipin and cytochalasin B). Imaging techniques and flow assisted cell sorting (FACS) were used to assess the cellular uptake of SLNs loaded with rhodamine 123 as a fluorescent probe. This study provided evidence that the cellular uptake of SLNs was energy-dependent, and the endocytosis of SLNs was mainly dependent on clathrin-mediated mechanisms. The establishment of entry mechanism of SLNs is of fundamental importance for future facilitation of SLNs as biological or drug carriers.
Liu, Dongfei; Jiang, Sunmin; Shen, Hong; Qin, Shan; Liu, Juanjuan; Zhang, Qing; Li, Rui; Xu, Qunwei
The preparation of solid lipid nanoparticles (SLNs) suffers from the drawback of poor incorporation of water-soluble drugs. The aim of this study was therefore to assess various formulation and process parameters to enhance the incorporation of a water-soluble drug (diclofenac sodium, DS) into SLNs prepared by the emulsion/solvent evaporation method. Results showed that the entrapment efficiency (EE) of DS was increased to approximately 100% by lowering the pH of dispersed phase. The EE of DS-loaded SLNs (DS-SLNs) had been improved by the existence of cosurfactants and increment of PVA concentration. Stabilizers and their combination with PEG 400 in the dispersed phase also resulted in higher EE and drug loading (DL). EE increased and DL decreased as the phospholipid/DS ratio became greater, while the amount of DS had an opposite effect. Ethanol turned out to be the ideal solvent making DS-SLNs. EE and DL of DS-SLNs were not affected by either the stirring speed or the viscosity of aqueous and dispersed phase. According to the investigations, drug solubility in dispersion medium played the most important role in improving EE.
Mulik, Rohit S; Mönkkönen, Jukka; Juvonen, Risto O; Mahadik, Kakasaheb R; Paradkar, Anant R
Photodegradation and low bioavailability are major hurdles for the therapeutic use of curcumin. Aim of the present study was to formulate transferrin-mediated solid lipid nanoparticles (Tf-C-SLN) to increase photostability, and enhance its anticancer activity against MCF-7 breast cancer cells. Tf-C-SLN were prepared by homogenization method and characterized by size, zeta potential, entrapment efficiency and stability, transmission electron microscopy (TEM), X-ray diffraction (XRD) and in vitro release study. Microplate analysis and flow cytometry techniques were used for cytotoxicity and apoptosis study. The physical characterization showed the suitability of method of preparation. TEM and XRD study revealed the spherical nature and entrapment of curcumin in amorphous form, respectively. The cytotoxicity, ROS and cell uptake was found to be increased considerably with Tf-C-SLN compared to curcumin solubilized surfactant solution (CSSS) and curcumin-loaded SLN (C-SLN) suggesting the targeting effect. AnnexinV-FITC/PI double staining, DNA analysis and reduced mitochondrial potential confirmed the apoptosis. The flow cytometric studies revealed that the anticancer activity of curcumin is enhanced with Tf-C-SLN compared to CSSS and C-SLN, and apoptosis is the mechanism underlying the cytotoxicity. The present study indicated the potential of Tf-C-SLN in enhancing the anticancer effect of curcumin in breast cancer cells in vitro.
Sandri, Giuseppina; Bonferoni, Maria Cristina; D'Autilia, Francesca; Rossi, Silvia; Ferrari, Franca; Grisoli, Pietro; Sorrenti, Milena; Catenacci, Laura; Del Fante, Claudia; Perotti, Cesare; Caramella, Carla
The management of difficult to heal wounds can considerably reduce the time required for tissue repairing and promote the healing process, minimizing the risk of infection. Silver compounds, especially silver sulfadiazine (AgSD), are often used to prevent or to treat wound colonization, also in presence of antibiotic-resistant bacteria. However, AgSD has been shown to be cytotoxic in vitro toward fibroblasts and keratinocytes and consequently to retard wound healing in vivo. Recently, platelet lysate (PL) has been proposed in clinical practice for the healing of persistent lesions. The aim of the present work was the development of wound dressings based on AgSD loaded in solid lipid nanoparticles (SLNs), to be used in association with PL for the treatment for skin lesions. SLN were based on chondroitin sulfate and sodium hyaluronate, bioactive polymers characterized by well-known tissue repairing properties. The encapsulation of AgSD in SLN aimed at preventing the cytotoxic effect of the drug on normal human dermal fibroblasts (NHDFs) and at enabling the association of the drug with PL. SLN were loaded in wound dressings based on hydroxypropylmethyl cellulose (HPMC) or chitosan glutamate (CS glu). These polymers were chosen to obtain a sponge matrix with suitable elasticity and softness and, moreover, with good bioadhesive behavior on skin lesions. Dressings based on chitosan glutamate showed antimicrobial activity with and without PL. Even though further in vivo evaluation could be envisaged, chitosan based dressings demonstrated to be a suitable prototype for the treatment for skin lesions.
Genç, Lütfi; Kutlu, H Mehtap; Güney, Gamze
Nanostructure-mediated drug delivery, a key technology for the realization of nanomedicine, has the potential to improve drug bioavailability, ameliorate release deviation of drug molecules and enable precision drug targeting. Due to their multifunctional properties, solid lipid nanoparticles (SLNs) have received great attention of scientists to find a solution to cancer. Vitamin supplements may contribute to a reduction in the risk of cancer. Vitamin B12 has several characteristics that make it an attractive entity for cancer treatment and possible therapeutic applications. The aim of this study was to produce B12-loaded SLNs (B12-SLNs) and determine the cytotoxic effects of B12-SLNs on H-Ras 5RP7 and NIH/3T3 control cell line. Results obtained by MTT assay, transmission electron and confocal microscopy showed that B12-loaded SLNs are more effective than free vitamin B12 on cancer cells. In addition, characterization studies indicate that while the average diameter of the B12 was about 650 nm, B12-SLNs were about 200 nm and the drug release efficiency of vit. B12 by means of SLNs increased up to 3 h. These observations point to the fact that B12-SLNs could be used as carrier systems due to the therapeutic effects on cancer.
Wissing, S A; Müller, R H
The aim of this study was the comparison of two different formulations (solid lipid nanoparticles (SLN) and conventional o/w emulsion) as carrier systems for the molecular sunscreen oxybenzone. The influence of the carrier on the rate of release was studied in vitro with a membrane-free model. The release rate could be decreased by up to 50% with the SLN formulation. Further in vitro measurements with static Franz diffusion cells were performed. In vivo, penetration of oxybenzone into stratum corneum on the forearm was investigated by the tape stripping method. It was shown that the rate of release is strongly dependent upon the formulation and could be decreased by 30-60% in SLN formulations. In all test models, oxybenzone was released and penetrated into human skin more quickly and to a greater extent from the emulsions. The rate of release also depends upon the total concentration of oxybenzone in the formulation. In vitro-in vivo correlations could be made qualitatively.
Khameneh, Bahman; Halimi, Vahid; Jaafari, Mahmoud Reza; Golmohammadzadeh, Shiva
Objective(s): In the current study, sunscreen and moisturizing properties of solid lipid nanoparticle (SLN)-safranal formulations were evaluated. Materials and Methods: Series of SLN were prepared using glyceryl monostearate, Tween 80 and different amounts of safranal by high shear homogenization, and ultrasound and high-pressure homogenization (HPH) methods. SLN formulations were characterized for size, zeta potential, morphology, thermal properties, and encapsulation efficacy. The Sun Protection Factor (SPF) of the products was determined in vitro using transpore tape. The moisturizing activity of the products was also evaluated by corneometer. Results: The SPF of SLN-safranal formulations was increased when the amount of safranal increased. Mean particle size for all formulas was approximately 106 nm by probe sonication and 233 nm using HPH method. The encapsulation efficiency of safranal was around 70% for all SLN-safranal formulations. Conclusion: The results conclude that SLN-safranal formulations were found to be effective for topical delivery of safranal and succeeded in providing appropriate sunscreen properties. PMID:25810877
Battaglia, Luigi; Gallarate, Marina; Peira, Elena; Chirio, Daniela; Solazzi, Ilaria; Giordano, Susanna Marzia Adele; Gigliotti, Casimiro Luca; Riganti, Chiara; Dianzani, Chiara
Glioblastoma, the most common primary brain tumor in adults, has an inauspicious prognosis, given that overcoming the blood-brain barrier is the major obstacle to the pharmacological treatment of brain tumors. As neoangiogenesis plays a key role in glioblastoma growth, the US Food and Drug Administration approved bevacizumab (BVZ), an antivascular endothelial growth factor antibody for the treatment of recurrent glioblastoma in patients whose the initial therapy has failed. In this experimental work, BVZ was entrapped in solid lipid nanoparticles (SLNs) prepared by the fatty-acid coacervation technique, thanks to the formation of a hydrophobic ion pair. BVZ activity, which was evaluated by means of four different in vitro tests on HUVEC cells, increased by 100- to 200-fold when delivered in SLNs. Moreover, SLNs can enhance the permeation of fluorescently labelled BVZ through an hCMEC/D3 cell monolayer—an in vitro model of the blood brain barrier. These results are promising, even if further in vivo studies are required to evaluate the effective potential of BVZ-loaded SLNs in glioblastoma treatment.
Chen, Guohua; Zeng, Shuang; Jia, Huaijie; He, Xiaobing; Fang, Yongxiang; Jing, Zhizhong; Cai, Xuepeng
In this paper, we investigated the enhancement of adjuvant effects of porcine IL-2 (pIL-2) by packaging it into a solid lipid nanoparticle (SLN) delivery system. SLN-pIL-2 was prepared using hydrogenated castor oil and Polylactide-co-glycolide by double emulsion solvent evaporation methods (w/o/w). In animal trials, BALB/c mice were immunized with inactivated foot and mouth disease virus (FMDV) antigen combined with the SLN-pIL-2 adjuvant on days 0 and 14. Antibody titer, splenocyte proliferation, and secretion of IFN-γ and IL-4 cytokines were determined. Our results showed that SLN-pIL-2 could significantly enhance FMDV-specific antibody level compared with recombinant pIL-2 alone (p<0.05). In addition, SLN-pIL-2 significantly increased the proliferative responses of antigen-specific spleen cells. Furthermore, SLN-pIL-2 induced the secretion of IFN-γ at a level higher than that induced by recombinant pIL-2 alone. Our results indicate that packaging recombinant pIL-2 in SLNs can be an effective way of boosting the effectiveness of pIL-2 as an adjuvant to enhance immune responses of vaccines.
Radaic, Allan; de Paula, Eneida; de Jesus, Marcelo Bispo
Several scientific hurdles still have to be overcome before gene therapy becomes a reality. One of them is the development of safe and efficient gene delivery system. Here, we have employed factorial design to optimize the production of solid lipid nanoparticles (SLN) for gene delivery. A 2 x 3 full-factorial experimental design was used for the optimization of SLNs formulations. The variables were defined by the components of the formulation: concentration of stearic acid, DOTAP, and Pluronic F68 at two levels (-1, 1) and 3 central points (0). Different SNL formulations were prepared by varying the amount of components and several properties were tested, including their capacity to accommodate DNA and protection against DNase degradation, colloidal stability, in vitro cytotoxicity, and transfection efficiency in prostate cancer cells. Finally, response Surface Methodology was used to select the most effective formulation for gene delivery to prostate cancer cells in vitro. In conclusion, this study revealed that stearic acid and Pluronic F68 were determinant to SLN size and stability, respectively, while small amounts of DOTAP are essential for a successful transfection.
Mosallaei, Navid; Jaafari, Mahmoud Reza; Hanafi-Bojd, Mohammad Yahya; Golmohammadzadeh, Shiva; Malaekeh-Nikouei, Bizhan
The aim of the present study was to prepare, characterize, and evaluate solid lipid nanoparticles (SLNs) containing docetaxel (DTX) to improve the efficacy of this chemotherapeutic agent. SLNs containing DTX (SLN-DTX) were prepared by microemulsion and probe sonication techniques. In vitro cytotoxicity of SLN-DTX compared with Taxotere® (TXT) was evaluated on colorectal (C-26) and malignant melanoma (A-375) cell lines. Cellular uptake experiment was also carried out on C-26 cells. In in vivo tests, tumor inhibitory efficacy and survival were compared with TXT on C-26-implanted BALB/c mice. SLN-DTX particle size was 180 nm and PDI of 0.2 with spherical shape. Encapsulation efficacy was more than 98%. SLN-DTX at concentration of 100 μM caused 100% and 99.9% viability reduction in C-26 and A-375 after 48 and 72 h, respectively. The half maximal inhibitory concentration (IC50 ) of SLN-DTX on C-26 and A-375 was respectively 0.769 and 28.132 μM after 24 h. DTX cell uptake from SLN-DTX was remarkably higher than TXT. SLN-DTX showed better tumor inhibitory efficacy and survival at a dose of 10 mg/kg versus 10 and 20 mg/kg TXT. In conclusion, the results of the present study showed that the efficacy of SLN-DTX was better than TXT in cell-uptake and in vivo experiments.
Martins, Susana M; Sarmento, Bruno; Nunes, Cláudia; Lúcio, Marlene; Reis, Salette; Ferreira, Domingos C
This study intended to investigate the ability of solid lipid nanoparticles (SLN) to deliver camptothecin into the brain parenchyma after crossing the blood-brain barrier. For that purpose, camptothecin-loaded SLN with mean size below 200 nm, low polydispersity index (<0.25), negative surface charge (-20 mV), and high camptothecin association efficiency (>94%) were produced. Synchrotron small and wide angle X-ray scattering (SAXS/WAXS) analysis indicates that SLN maintain their physical stability in contact with DMPC membrane, whereas SLN change the lamellar structure of DMPC into a cubic phase, which is associated with efficient release of the incorporated drugs. Cytotoxicity studies against glioma and macrophage human cell lines revealed that camptothecin-loaded SLN induced cell death with the lowest maximal inhibitory concentration (IC50) values, revealing higher antitumour activity of camptothecin-loaded SLN against gliomas. Furthermore, in vivo biodistribution studies of intravenous camptothecin-loaded SLN performed in rats proved the positive role of SLN on the brain targeting since significant higher brain accumulation of camptothecin was observed, compared to non-encapsulated drug. Pharmacokinetic studies further demonstrated lower deposition of camptothecin in peripheral organs, when encapsulated into SLN, with consequent decrease in potential side toxicological effects. These results confirmed the potential of camptothecin-loaded SLN for antitumour brain treatments.
Bhalekar, Mangesh R; Madgulkar, Ashwini R; Desale, Puja S; Marium, Gyce
The purpose of this work was to formulate piperine solid lipid nanoparticle (SLN) dispersion to exploit its efficacy orally and topically. Piperine SLN were prepared by melt emulsification method and formula was optimized by the application of 3(2) factorial design. The nanoparticulate dispersion was evaluated for particle size, entrapment efficiency and zeta potential (ZP). Optimized batch (128.80 nm average size, 78.71% entrapment efficiency and -23.34 mV zeta potential) was characterized for differential scanning calorimetry (DSC), X-ray diffraction which revealed amorphous nature of piperine in SLN. The prepared SLN were administered orally and topically to CFA-induced arthritic rats. Ex vivo study using Franz diffusion cell indicate that piperine from SLN gel formulation accumulates in the skin. Pharmacodynamic study result indicates both the topical and oral piperine evoked a significant response compared to orally administered chloroquine suspension. The results of ELISA show significant reduction in TNFα in treated rat which might be the reason behind the DMARD action of piperine SLN.
Bikkad, Mahesh L; Nathani, Ajaz H; Mandlik, Satish K; Shrotriya, Shilpa N; Ranpise, Nisharani S
The clinical use of halobetasol propionate (HP) is related to some adverse effects like irritation, pruritus and stinging. The purpose of this work was to construct HP-loaded solid lipid nanoparticles (HP-SLN) formulation with skin targeting to minimizing the adverse side effects and providing a controlled release. HP-SLN were prepared by solvent injection method and formula was optimized by the application of 3(2) factorial design. The nanoparticulate dispersion was evaluated for particle size and entrapment efficiency (EE). Optimized batch was characterized for differential scanning calorimetry (DSC), scanning electron microscopy, X-ray diffraction study and finally incorporated into polymeric gels of carbopol for convenient application. The nanoparticulate gels were evaluated comparatively with the commercial product with respect to ex-vivo skin permeation and deposition study on human cadaver skins and finally skin irritation study. HP-SLN showed average size between 200 nm and 84-94% EE. DSC studies revealed no drug-excipient incompatibility and amorphous dispersed of HP in SLN. Ex vivo study of HP-SLN loaded gel exhibited prolonged drug release up to 12 h where as in vitro drug deposition and skin irritation studies showed that HP-SLN formulation can avoid the systemic uptake, better accumulative uptake of the drug and nonirritant to the skin compared to marketed formulation. These results indicate that the studied HP-SLN formulation represent a promising carrier for topical delivery of HP, having controlled drug release, and potential of skin targeting with no skin irritation.
Chirio, Daniela; Gallarate, Marina; Peira, Elena; Battaglia, Luigi; Muntoni, Elisabetta; Riganti, Chiara; Biasibetti, Elena; Capucchio, Maria Teresa; Valazza, Alberto; Panciani, Pierpaolo; Lanotte, Michele; Annovazzi, Laura; Caldera, Valentina; Mellai, Marta; Filice, Gaetano; Corona, Silvia; Schiffer, Davide
Paclitaxel loaded solid lipid nanoparticles (SLN) of behenic acid were prepared with the coacervation technique. Generally, spherical shaped SLN with mean diameters in the range 300–600 nm were obtained. The introduction of charged molecules, such as stearylamine and glycol chitosan into the formulation allowed to obtain positive SLN with Zeta potential in the 8-20 mV range and encapsulation efficiency in the 25–90% range.Blood–brain barrier (BBB) permeability, tested in vitro through hCMEC/D3 cells monolayer, showed a significantly increase in the permeation of Coumarin-6, used as model drug, when vehicled in SLN. Positive-charged SLN do not seem to enhance permeation although stearylamine-positive SLN resulted the best permeable formulation after 24 h.Cytotoxicity studies on NO3 glioblastoma cell line demonstrated the maintenance of cytotoxic activity of all paclitaxel-loaded SLN that was always unmodified or greater compared with free drug. No difference in cytotoxicity was noted between neutral and charged SLN.Co-culture experiments with hCMEC/D3 and different glioblastoma cells evidenced that, when delivered in SLN, paclitaxel increased its cytotoxicity towards glioblastoma cells.
Pandurangan, Dinesh Kumar; Bodagala, Prathima; Palanirajan, Vijayaraj Kumar; Govindaraj, Saravanan
In the present investigation, solid lipid nanoparticles (SLNs)-loaded in situ gel with voriconazole drug was formulated. Further, the formulation was characterized for pH, gelling capacity, entrapment efficiency, in vitro drug release, drug content, and viscosity. Voriconazole is an antifungal drug used to treat various infections caused by yeast or other types of fungi. Film hydration technique was used to prepared SLNs from lecithin and cholesterol. Based on the entrapment efficiency 67.2-97.3% and drug release, the optimized formulation NF1 of SLNs was incorporated into in situ gels. The in situ gels were prepared using viscosity-enhancing polymers such as Carbopol and (hydroxypropyl)methyl cellulose (HPMC). Formulated SLN in situ gel formulations were characterized, which showed pH 4.9-7.1, drug content 65.69-96.3%, and viscosity (100 rpm) 120-620 cps. From the characterizations given above, F6 was optimized and evaluated for microbial assay and ocular irritation studies. Microbial assay was conducted by the cup-plate method using Candida albicans as the test organism. An ocular irritation study was conducted on albino rabbits. The results revealed that there was no ocular damage to the cornea, conjunctiva, or iris. Stability studies were carried out on the F6 formulation for 3 months, which showed that the formulation had good stability. These results indicate that the studied SLNs-loaded in situ gel is a promising vehicle for ocular delivery. PMID:27014620
Ren, Jungang; Zou, Meijuan; Gao, Ping; Wang, Yue; Cheng, Gang
The main purpose of this research was to prepare borneol-modified and non-borneol ganciclovir-loaded solid lipid nanoparticles (SLNs) to study whether borneol could enhance the transport of ganciclovir (GCV) incorporated in SLN to the brain in mice after their intravenous administration. Ganciclovir injection (GCV-inj) was selected as a control. The SLNs were prepared using a modified microemulsion method. Pharmacokinetic and biodistribution studies were conducted in kunming mice after intravenous administration of GCV-inj, GCV solid lipid nanoparticles without borneol (GCV-SLN), and three types of GCV solid lipid nanoparticles containing different ratios of borneol (GCVb-SLN). It was found that, in plasma, the area under the concentration-time curve (AUC 0 ∼ t) for GCVb-SLN and GCV-SLN was greater than that for the GCV-inj. In the brain, the AUC 0 ∼ t of GCVb-SLN was significantly increased compared with that of a GCV-inj and GCV-SLN. In the other mouse tissues, the peak concentration of GCV achieved was always lower after the injection of any of the four types of SLN than after the commercial injection. These results indicate that GCV-SLN modified with borneol enhances the transport of ganciclovir to the brain. Therefore, SLN modified with borneol is a potential delivery system for transporting drugs to the central nervous system (CNS).
Misra, Shubham; Chopra, Kanwaljit; Sinha, V R; Medhi, Bikash
Galantamine hydrobromide, a promising acetylcholinesterase inhibitor is reported to be associated with cholinergic side effects. Its poor brain penetration results in lower bioavailability to the target site. With an aim to overcome these limitations, solid-lipid nanoparticulate formulation of galantamine hydrobromide was developed employing biodegradable and biocompatible components. The selected galantamine hydrobromide-loaded solid-lipid nanoparticles offered nanocolloidal with size lower than 100 nm and maximum drug entrapment 83.42 ± 0.63%. In vitro drug release from these spherical drug-loaded nanoparticles was observed to be greater than 90% for a period of 24 h in controlled manner. In vivo evaluations demonstrated significant memory restoration capability in cognitive deficit rats in comparison with naive drug. The developed carriers offered approximately twice bioavailability to that of plain drug. Hence, the galantamine hydrobromide-loaded solid-lipid nanoparticles can be a promising vehicle for safe and effective delivery especially in disease like Alzheimer's.
Pradhan, Madhulika; Singh, Deependra; Singh, Manju Rawat
Aim of the study was to develop solid lipid nanoparticles (SLN) of triamcinolone acetonide (TA) and to study the effect of various process variables in order to optimize the formulation for effective delivery. Drug loaded SLNs were successfully prepared and characterized by TEM, XRD and DSC study. Process variables like surfactant concentration, drug concentration, lipid concentration etc. showed significant effect on the particle size and entrapment efficiency. SLNs exhibited prolonged drug release following Higuchi release kinetics (R(2) = 0.9909). In vitro skin distribution study demonstrated systemic escape of drug from TA loaded SLNs which might eliminate side effects associated with systemic exposure.
Xie, Shuyu; Pan, Baoliang; Shi, Baoxin; Zhang, Zhuangzhi; Zhang, Xu; Wang, Ming; Zhou, Wenzhong
Hydatid disease caused by tapeworm is an increasing public health and socioeconomic concern. In order to enhance the therapeutic efficacy of praziquantel (PZQ) against tapeworm, PZQ-loaded hydrogenated castor oil solid lipid nanoparticle (PZQ-HCO-SLN) suspension was prepared by a hot homogenization and ultrasonication method. The stability of the suspension at 4°C and room temperature was evaluated by the physicochemical characteristics of the nanoparticles and in-vitro release pattern of the suspension. Pharmacokinetics was studied after subcutaneous administration of the suspension in dogs. The therapeutic effect of the novel formulation was evaluated in dogs naturally infected with Echinococcus granulosus. The results showed that the drug recovery of the suspension was 97.59% ± 7.56%. Nanoparticle diameter, polydispersivity index, and zeta potential were 263.00 ± 11.15 nm, 0.34 ± 0.06, and -11.57 ± 1.12 mV, respectively and showed no significant changes after 4 months of storage at both 4°C and room temperature. The stored suspensions displayed similar in-vitro release patterns as that of the newly prepared one. SLNs increased the bioavailability of PZQ 5.67-fold and extended the mean residence time of the drug from 56.71 to 280.38 hours. Single subcutaneous administration of PZQ-HCO-SLN suspension obtained enhanced therapeutic efficacy against tapeworm in infected dogs. At the dose of 5 mg/kg, the stool-ova reduction and negative conversion rates and tapeworm removal rate of the suspension were 100%, while the native PZQ were 91.55%, 87.5%, and 66.7%. When the dose reduced to 0.5 mg/kg, the native drug showed no effect, but the suspension still got the same therapeutic efficacy as that of the 5 mg/kg native PZQ. These results demonstrate that the PZQ-HCO-SLN suspension is a promising formulation to enhance the therapeutic efficacy of PZQ.
Suter, Franz; Schmid, Daniel; Wandrey, Franziska; Zülli, Fred
The cosmetic industry requires more and more expensive actives and ingredients such as retinol, coenzyme Q10, proteins, peptides and biotechnologically produced molecules. In this study, we demonstrate the development of a cost effective formulation of a nanostructured lipid carrier (NLC) or solid lipid nanoparticles (SLN) improving peptide delivery into skin. NLC or SLN are very suitable vehicles for the delivery of active ingredients into skin. The SLN, produced by using hot high pressure homogenization method combine advantages such as physical stability, protection of incorporated labile actives and controlled release. By the used method we dispersed the amorphous heptapeptide DEETGEF in shea butter and homogenized this pre-dispersion at 60°C together with the water phase using a Microfluidizer at 1000bar. The analysis of the obtained SLN-P7 showed a particle size of 173nm, incorporated peptide of 0.014%, entrapment efficiency of 90.8%, melting peak (DSC) of the core lipid of 27°C and a zeta potential of -54mV. By an ex vivo study with skin explants we could stimulate NQO1 (NAD(P)H quinone oxidoreductase), HMOX1 (Heme oxygenase-1) and PRDX1 (Peroxiredoxin-1) genes all of which are cell protecting enzymes. In a multicellular protection against UV induced stress study with skin explants we detected the formation of sun burn cells and the number and morphology of Langerhans cells. The application of our SLN-P7 formulation on skin explants led to a significant and dose dependent protection against UV irradiation. In the clinical suction blister study, irradiation with UVA light for two hours after final product application led to a statistically significant increase of the 8-OhdG (8-hydroxy-2'-deoxyguanosine) concentration in the human epidermis. The skin treated with our verum formulation showed a statistically significant 20% decrease in DNA damage compared to placebo. In conclusion, it was demonstrated that SLN technology enabled peptide delivery into skin
Sucrose ester stabilized solid lipid nanoparticles and nanostructured lipid carriers: I. Effect of formulation variables on the physicochemical properties, drug release and stability of clotrimazole-loaded nanoparticles
Das, Surajit; Kiong Ng, Wai; Tan, Reginald B. H.
The objective of this study was to develop and evaluate solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) utilizing sucrose ester as a stabilizer/emulsifier for the controlled release of drug/active. Both SLNs and NLCs were prepared using different sugar esters to screen out the most suitable stabilizer. Clotrimazole was used as a model active/drug. The effect of different formulation variables on the particle size, polydispersity index and drug encapsulation efficiency of SLNs and NLCs was evaluated and compared. SLNs and NLCs were physicochemically characterized and compared using Cryo-SEM, DSC and XRD. Furthermore, a drug release study of SLNs and NLCs was conducted. Finally, physicochemical stability (size, PI, ZP, EE) of the SLNs and NLCs was checked at 25 ± 2 °C and at 2-8 °C. Among the sucrose esters, D-1216 was found to be most suitable for both SLNs and NLCs. Formulation variables exhibited a significant impact on size, PI and EE of the nanoparticles. SLNs with ˜120 nm size, ˜0.23 PI, ˜I26I mV ZP, ˜87% EE and NLCs with ˜160 nm size, 0.15 PI, ˜I26I mV ZP, ˜88% EE were produced. Cryo-SEM revealed spherical particles with a smooth surface but did not exhibit any difference in surface morphology between SLNs and NLCs. DSC and XRD results demonstrated the disappearance of clotrimazole peak(s) in drug-loaded SLNs and NLCs. Faster drug release was observed from SLNs than NLCs. NLCs were found to be more stable than SLNs in terms of size, PI, EE and drug release. The results indicated that both SLNs and NLCs stabilized with sucrose ester D-1216 can be used as controlled release carriers although NLCs have an edge over SLNs.
Chen, J; Dai, W T; He, Z M; Gao, L; Huang, X; Gong, J M; Xing, H Y; Chen, W D
Curcumin has very broad spectrum of biological activities; however, photodegradation, short half-life and low bioavailability have limited its clinical application. Curcumin-loaded solid lipid nanoparticles were studied to overcome these problems. The aim of this study was to optimize the best formulation on curcumin-loaded solid lipid nanoparticles. Emulsion-evaporation and low temperature-solidification technique was applied with monostearin as lipid carriers. The single factor analysis and orthogonal design were used to optimize formulation and various parameters were investigate. By the optimisation of a single factor analysis and orthogonal test, the particles size, polydispersity index, zeta potential, encapsulation efficiency and drug loading capacity of the optimised formulation were 99.99 nm, 0.158, -19.9 mV, 97.86%, and 4.35%, respectively. The differential scanning calorimetry and X-ray diffraction analysis results demonstrated new structure was formed in nanoparticles. The release kinetics in vitro demonstrated curcumin-loaded solid lipid nanoparticles can control drug release. These studies confirmed that curcumin-loaded solid lipid nanoparticles could be prepared successfully with high drug entrapment efficiency and loading capacity. Curcumin-loaded solid lipid nanoparticles may be a promising drug delivery system to control drug release and improve bioavailability.
Svetlichny, G; Külkamp-Guerreiro, I C; Cunha, S L; Silva, F E K; Bueno, K; Pohlmann, A R; Fuentefria, A M; Guterres, S S
The aim of this work was to develop solid lipid nanoparticles (SLN) containing copaiba oil with and without allantoin (NCOA, NCO, respectively) and to evaluate their antifungal activity. Nanoparticle suspensions were prepared using a high homogenisation technique and characterised by dynamic light scattering, laser diffraction, nanoparticle tracking analysis, multiple light scattering analysis, high-pressure liquid chromatography, pH and rheology. The antifungal activities of the formulations were tested in vitro against the emergent yeasts Candida krusei and Candida parapsilosis, and the fungal pathogens of human skin Trichophyton rubrum and Microsporum canis. The dynamic light scattering analysis showed z-average diameters (intensity) between 118.63 ± 8.89 nm for the nanoparticles with both copaiba oil and allantoin and 126.06 ± 9.84nm for the nanoparticles with just copaiba oil. The D[4,3] determined by laser diffraction showed similar results of 123 ± 1.73 nm for the nanoparticles with copaiba oil and allantoin and 130 ± 3.6 nm for the nanoparticles with copaiba oil alone. Nanoparticle tracking analysis demonstrated that both suspensions had monomodal profiles and consequently, the nanoparticle populations were homogeneous. This analysis also corroborated the results of dynamic light scattering and laser diffraction, exhibiting a smaller mean diameter for the nanoparticles with copaiba oil and allantoin (143 nm) than for the nanoparticles with copaiba oil (204 nm). The physicochemical properties indicated that the dispersions were stable overtime. Rheology evidenced Newtonian behaviour for both suspensions. Antifungal susceptibility showed a MIC90 of 125 μg/mL (nanoparticles with copaiba oil) and 7.8 μg/mL (nanoparticles with copaiba oil and allantoin) against C. parapsilosis. The nanoparticles with copaiba oil and the nanoparticles with copaiba oil and allantoin presented a MIC90 of 500 μg/mL and 250 μg/mL, respectively, against C. krusei. The MIC90
Hamishehkar, Hamed; Same, Saeideh; Adibkia, Khosro; Zarza, Kamyar; Shokri, Javad; Taghaee, Mehran; Kouhsoltani, Maryam
The water content of the epidermis is a main factor in maintaining skin smoothness and elasticity and preventing skin dryness. Occlusive products can greatly affect skin hydration by forming a barrier on the skin following the topical administration of oil-based formulations. These products repair the skin barrier by restoring the skin lipids as well. Solid lipid nanoparticles (SLNs) have recently been introduced as a novel carrier with several benefits in pharmaceutics and cosmeceutics. It has been suggested that SLNs may have an occlusive effect following topical application. In this study, the occlusion effects of lipidic particles in different size ranges were investigated in vitro, ex vivo, and in vivo, and the results were compared with the positive (vaseline) and negative (blank) controls. Although larger lipidic particles showed better occlusion properties than nanoparticles in vitro, but ex vivo experiments confirmed the benefits of nanoparticles (almost 30% higher occlusion factor for particles in the range of 170 nm than ones in the range of 600 and 1800 nm). The superiority of SLN formulation to Vaseline as a positive reference was confirmed by the in vivo study. SLN formulation resulted in much thicker stratum corneum than Vaseline. It was indicated that in vitro and ex vivo study methods may not be a good reflective of the in vivo method for determining the occlusive properties of nanoparticulate systems. It was concluded that formulations containing SLNs can be used as efficient skin moisturizer products. PMID:26752986
Fang, Yi-Ping; Chuang, Chih-Hung; Wu, Pao-Chu; Huang, Yaw-Bin; Tzeng, Cherng-Chyi; Chen, Yeh-Long; Liu, Ya-Ting; Tsai, Yi-Hung; Tsai, Ming-Jun
Amsacrine analog is a novel chemotherapeutic agent that provides potentially broad antitumor activity when compared to traditional amsacrine. However, the major limitation of amsacrine analog is that it is highly lipophilic, making it nonconductive to intravenous administration. The aim of this study was to utilize solid lipid nanoparticles (SLN) to resolve the delivery problem and to investigate the biodistribution of amsacrine analog-loaded SLN. Physicochemical characterizations of SLN, including particle size, zeta potential, entrapment efficiency, and stability, were evaluated. In vitro release behavior was also measured by the dialysis method. In vivo pharmacokinetics and biodistribution behavior of amsacrine analog were investigated and incorporated with a non invasion in vivo imaging system to confirm the localization of SLN. The results showed that amsacrine analog-loaded SLN was 36.7 nm in particle size, 0.37 in polydispersity index, and 34.5±0.047 mV in zeta potential. More than 99% of amsacrine analog was successfully entrapped in the SLN. There were no significant differences in the physicochemical properties after storage at room temperature (25°C) for 1 month. Amsacrine analog-loaded SLN maintained good stability. An in vitro release study showed that amsacrine analog-loaded SLN sustained a release pattern and followed the zero equation. An in vivo pharmacokinetics study showed that amsacrine analog was rapidly distributed from the central compartment to the tissue compartments after intravenous delivery of amsacrine analog-loaded SLN. The biodistribution behavior demonstrated that amsacrine analog mainly accumulated in the lungs. Noninvasion in vivo imaging system images also confirmed that the drug distribution was predominantly localized in the lungs when IR-780-loaded SLN was used. PMID:27019595
Wang, Taoran; Ma, Xiaoyu; Lei, Yu; Luo, Yangchao
Solid lipid nanoparticles (SLNs) are regarded as promising carriers to improve the safety and effectiveness of delivery for drugs and nutrients, however, the clinic applications for oral administration are limited by their poor stability in gastrointestinal conditions. In this study, surface modification was explored to confer new physicochemical properties to SLNs and thus achieve enhanced functionalities. Novel SLNs with biopolymeric double layer (DL) coating using two natural biopolymers, i.e. caseinate (NaCas) and pectin, were prepared to encapsulate and deliver curcumin, a lipophilic bioactive compound studied as a model drug/nutrient. The DL coating was chemically cross-linked by creating covalent bonds between NaCas and pectin, using two different cross-linkers, i.e. glutaraldehyde (GA) and 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-Hydroxysuccinimide (EDC/NHS). Prior to cross-linking, the mean particle size, polydispersity index and zeta potential of DL-SLNs were 300-330nm, 0.25-0.30, -45-40mV, respectively. It was found that cross-linking with GA had a more prominent effect on particle size and polydispersity index than EDC/NHS. The cross-linking process significantly improved physicochemical properties of DL-SLNs, resulting in higher encapsulation efficiency and loading capacity, better stability and slower release profile in simulated gastrointestinal conditions. Particularly, an optimal zero-order release kinetic was observed for EDC/NHS crosslinked DL-SLNs. The electron microscopy revealed that both cross-linked DL-SLNs exhibited spherical shape with homogeneous size and smooth surface. Encapsulation of curcumin in SLNs dramatically enhanced its antioxidant activity in aqueous condition. The cross-linking process further helped spray drying of SLNs by forming homogenous powder particles. These results indicated that coating with cross-linked polymers could significantly improve the physicochemical properties of SLNs and expand their potentials as
Kalhapure, Rahul S; Sonawane, Sandeep J; Sikwal, Dhiraj R; Jadhav, Mahantesh; Rambharose, Sanjeev; Mocktar, Chunderika; Govender, Thirumala
New and effective strategies to transform current antimicrobials are required to address the increasing issue of microbial resistance and declining introduction of new antibiotic drugs. In this context, metal complexes of known drugs and nano delivery systems for antibiotics are proving to be promising strategies. The aim of the study was therefore to synthesize a silver complex of clotrimazole and formulate it into a nano delivery system for enhanced and sustained antibacterial activity against susceptible and resistant Staphylococcus aureus. A silver complex of clotrimazole was synthesized, characterized and further encapsulated into solid lipid nanoparticles to evaluate its antibacterial activity against S. aureus and methicillin-resistant S. aureus (MRSA). An in vitro cytotoxicity study was performed on HepG2 cell lines to assess the overall biosafety of the synthesized clotrimazole silver complex to mammalian cells, and was found to be non-toxic to mammalian cells (cell viability >80%). The minimum inhibitory concentrations (MIC) of clotrimazole and clotrimazole-silver were 31.25 and 9.76 μg/mL against S. aureus, and 31.25 and 15.62 against MRSA, respectively. Clotrimazole SLNs exhibited MIC values of 104 and 208 μg/mL against both MSSA and MRSA at the end of 18 and 36 h, respectively, but thereafter completely lost its antibacterial activity. Clotrimazole-silver SLNs had an MIC value of 52 μg/mL up to 54 h, after which the MIC value was 104 μg/mL against both strains at the end of 72 h. Thus, clotrimazole-silver SLNs was found to be an efficient nanoantibiotic.
Chen, Ruie; Wang, Shengpeng; Zhang, Jinming; Chen, Meiwan; Wang, Yitao
Aloe-emodin (AE) is a promising anti-tumor candidate for its significant activity against various tumors such as lung cancer, hepatic cancer, breast cancer and so on. Nevertheless, AE is clinically limited due to its poor water solubility and low bioavailability. This study was designed to prepare AE-loaded solid lipid nanoparticles (AE-SLNs) in an attempt to improve the anti-cancer efficacy of AE. The AE-SLNs were prepared with optimized prescription using high pressure homogenization (HPH) technique. Ultimately, the AE-SLNs showed stable particle size at 88.9 ± 5.2 nm, ideal drug entrapment efficiency (EE) of 97.71 ± 0.5% and good stability with regard to zeta-potential as high as -42.8 mV. The in vitro release profiles revealed that AE achieved sustained release by loading into SLNs. Moreover, AE-SLNs showed significantly higher in vitro cytotoxicity against human breast cancer MCF-7 cells and human hepatoma HepG2 cells as compared to the AE solution, while they showed no significant toxicity on human mammary epithelial MCF-10A cells. Hoechst 33342 staining and Annexin V/PI double staining indicated that AE-SLNs induced higher apoptotic rates in MCF-7 cells. Further study elucidated that the improved anti-cancer efficacy may be attributed to the increased cellular uptake of AE. Based on these findings, we believe that the development of AE-SLNs is an effective way for improving the anti-cancer efficacy of AE.
Gao, Gang; Liu, Ya; Zhou, Chang-Hua; Jiang, Ping; Sun, Jian-Jun
Background: Antioxidants and the duration of treatment after noise exposure on hearing recovery are important. We investigated the protective effects of an antioxidant substance, edaravone, and its slow-release dosage form, edaravone solid lipid nanoparticles (SLNs), in steady noise-exposed guinea pigs. Methods: SLNs loaded with edaravone were produced by an ultrasound technique. Edaravone solution or edaravone SLNs were administered by intratympanic or intravenous injection after the 1st day of noise exposure. Guinea pigs were exposed to 110 dB sound pressure level (SPL) noise, centered at 0.25–4.0 kHz, for 4 days at 2 h/d. After noise exposure, the guinea pigs underwent auditory brainstem response (ABR) threshold measurements, reactive oxygen species (ROS) were detected in their cochleas with electron spin resonance (ESR), and outer hair cells (OHCs) were counted with silvernitrate (AgNO3) staining at 1, 4, and 6 days. Results: The ultrasound technique was able to prepare adequate edaravone SLNs with a mean particle size of 93.6 nm and entrapment efficiency of 76.7%. Acoustic stress-induced ROS formation and edaravone exerted a protective effect on the cochlea. Comparisons of hearing thresholds and ROS changes in different animal groups showed that the threshold shift and ROS generation were significantly lower in treated animals than in those without treatment, especially in the edaravone SLN intratympanic injection group. Conclusions: Edaravone SLNs show noticeable slow-release effects and have certain protective effects against noise-induced hearing loss (NIHL). PMID:25591563
Abuasal, Bilal S; Lucas, Courtney; Peyton, Breanne; Alayoubi, Alaadin; Nazzal, Sami; Sylvester, Paul W; Kaddoumi, Amal
γ-Tocotrienol (γ-T3), a member of the vitamin E family, has been reported to possess an anticancer activity. γ-T3 is a lipophilic compound with low oral bioavailability. Previous studies showed that γ-T3 has low intestinal permeability. Thus, we have hypothesized that enhancing γ-T3 intestinal permeability will increase its oral bioavailability. Solid lipid nanoparticles (SLN) were tested as a model formulation to enhance γ-T3 permeability and bioavailability. γ-T3 intestinal permeability was compared using in situ rat intestinal perfusion, followed by in vivo relative oral bioavailability studies. In addition, in vitro cellular uptake of γ-T3 from SLN was compared to mixed micelles (MM) in a time and concentration-dependent studies. To elucidate the uptake mechanism(s) of γ-T3 from SLN and MM the contribution of NPC1L1 carrier-mediated uptake, endocytosis and passive permeability were investigated. In situ studies demonstrated SLN has tenfold higher permeability than MM. Subsequent in vivo studies showed γ-T3 relative oral bioavailability from SLN is threefold higher. Consistent with in situ results, in vitro concentration dependent studies revealed γ-T3 uptake from SLN was twofold higher than MM. In vitro mechanistic characterization showed that while endocytosis contributes to γ-T3 uptake from both formulations, the reduced contribution of NPC1L1 to the transport of γ-T3, and passive diffusion enhancement of γ-T3 are primary explanations for its enhanced uptake from SLN. In conclusion, SLN successfully enhanced γ-T3 oral bioavailability subsequent to enhanced passive permeability.
Dwivedi, Pankaj; Khatik, Renuka; Khandelwal, Kiran; Taneja, Isha; Raju, Kanumuri Siva Rama; Wahajuddin; Paliwal, Sarvesh Kumar; Dwivedi, Anil Kumar; Mishra, Prabhat Ranjan
Arteether (ART), an artemisinin derivative, is a life saving drug for multiple drug resistant malaria. It has a deliverance effect in Falciparum malaria and cerebral malaria. We have prepared solid lipid nanoparticles (SLN) by high pressure homogenization (HPH) technique. ART-loaded SLN (ART-SLN) has been produced reproducibly with homogeneous particle size. ART-SLN was characterized for their size measured by Zetasizer Nano-ZS, Malvern, UK and by high resolution transmission electron microscopy (HR-TEM) and which was found to be 100 ± 11.2 nm. The maximum percentage entrapment efficiency (%EE) determined with the high-performance liquid chromatography (HPLC) has been found to be 69 ± 4.2% in ART-SLN-3. The release pattern from ART-SLN revealed that the release of ART is slow but time-dependent manner, which is desirable as it will help to protect the acid degradation of ART in stomach. The percentage cytotoxicity of blank SLN has been found within the acceptable range. The pharmacokinetics results indicated that ART-SLN-3 absorption has been significantly enhanced in comparison to ART in aqueous suspension and ART in ground nut oil (GNO) in rats. The % relative bioavailability (RB%) of ART-SLN to the ART in GNO and ART in aqueous suspension in rats was 169.99% and 7461%, respectively which was found to be significantly high in both the cases. From the results, it can be concluded that ART-SLN offers a new approach to improve the oral bioavailability of ART.
Chetoni, Patrizia; Burgalassi, Susi; Monti, Daniela; Tampucci, Silvia; Tullio, Vivian; Cuffini, Anna Maria; Muntoni, Elisabetta; Spagnolo, Rita; Zara, Gian Paolo; Cavalli, Roberta
Eye drops are widely accepted as formulations for targeting the anterior segment notwithstanding their limitations in terms of bioavailability. The unique structure of the eye requires specially-designed formulations able to favor the pharmacokinetic profile of administered drugs, mainly minimizing the influence of ocular barriers. Nanotechnology-based delivery systems lead to significant technological and therapeutical advantages in ophthalmic therapy. The aim of the present study was to determine whether tobramycin as ion-pair incorporated in mucoadhesive Solid Lipid Nanoparticles (SLN) reaches the inner parts of the eye favoring drug activity. After technological characterization of the tobramycin entrapped SLN formulation (Tobra-SLN), a pharmacokinetic study in rabbits after topical instillation and intravenous administration of the formulation has been carried out. In addition, the intracellular activity of Tobra-SLN formulation against phagocytosed Pseudomonas aeruginosa was investigated. The SLN were spherical in shape, and showed a hydrodynamic diameter of about 80nm, a negative zeta potential (-25.7mV) with a polydispersity index of 0.15, representative of a colloidal dispersion with high quality, characterized by an unimodal relatively narrow size distribution. As demonstrated by FTIR and DSC, tobramycin ion-pair could be concentrated into lipid inner core of SLN, without interaction with the stearic acid, thus promoting a slow and constant drug release profile in the dissolution medium. Surprisingly, the drug concentration was significantly higher in all ocular tissues after ocular and intravenous administration of Tobra-SLN formulation with respect to reference formulations and only Tobra-SLN allowed the penetration of drug into retina. Furthermore, the use of Tobra-SLN resulted in both higher intraphagocytic antibiotic concentrations in polymorphonuclear granulocytes and greater bactericidal activity against intracellular Pseudomonas aeruginosa
Ruktanonchai, Uracha; Limpakdee, Surachai; Meejoo, Siwaporn; Sakulkhu, Usawadee; Bunyapraphatsara, Nuntavan; Junyaprasert, Varaporn; Puttipipatkhachorn, Satit
This present study was aimed at investigating the effect of the crystallinity of cetyl palmitate based solid lipid nanoparticles (SLNs) on the physical properties of γ-oryzanol-loaded SLNs. SLNs consisting of varying ratios of cetyl palmitate and γ-oryzanol were prepared. Their hydrodynamic diameters were in the range 210-280 nm and the zeta potentials were in the range -27 to -35 mV. The size of SLNs increased as the amount of cetyl palmitate decreased whereas no significant change of zeta potentials was found. Atomic force microscopy pictures indicated the presence of disc-like particles. The crystallinity of SLNs, determined by differential scanning calorimetry and powder x-ray diffraction, was directly dependent on the ratio of cetyl palmitate to γ-oryzanol and decreased with decreasing cetyl palmitate content in the lipid matrix. Varying this ratio in the lipid mix resulted in a shift in the melting temperature and enthalpy, although the SLN structure remained unchanged as an orthorhombic lamellar lattice. This has been attributed to a potential inhibition by γ-oryzanol during lipid crystal growth as well as a less ordered structure of the SLNs. The results revealed that the crystallinity of the SLNs was mainly dependent on the solid lipid, and that the crystallinity has an important impact on the physical characteristics of active-loaded SLNs.
Tran, Tuan Hiep; Choi, Ju Yeon; Ramasamy, Thiruganesh; Truong, Duy Hieu; Nguyen, Chien Ngoc; Choi, Han-Gon; Yong, Chul Soon; Kim, Jong Oh
Hyaluronic acid (HA)-decorated solid lipid nanoparticles (SLNs) were developed for tumor-targeted delivery of vorinostat (VRS), a histone deacetylase inhibitor. HA, a naturally occurring polysaccharide, which specifically binds to the CD44 receptor, was coated on a cationic lipid core through electrostatic interaction. After the optimization process, HA-coated VRS-loaded SLNs (HA-VRS-SLNs) were spherical, core-shell nanoparticles, with small size (∼100 nm), negative charge (∼-9 mV), and narrow size distribution. In vitro release profile of HA-VRS-SLNs showed a typical bi-phasic pattern. In addition, the intracellular uptake of HA-VRS-SLNs was significantly enhanced in CD44 overexpressing cells, A549 and SCC-7 cells, but reduced when HA-VRS-SLNs were incubated with SCC-7 cells pretreated with HA or MCF-7 cells with low over-expressed CD44. Of particular importance, HA-VRS-SLNs were more cytotoxic than the free drug and VRS-SLNs in A549 and SCC-7 cells. In addition, HA shell provided longer blood circulation and reduced VRS clearance rate in rats, resulting in enhanced higher plasma concentration and bioavailability. These results clearly indicated the potential of the HA-functionalized lipid nanoparticle as a nano-sized drug formulation for chemotherapy.
Ji, Peng; Yu, Tong; Liu, Ying; Jiang, Jie; Xu, Jie; Zhao, Ying; Hao, Yanna; Qiu, Yang; Zhao, Wenming; Wu, Chao
Naringenin (NRG), a flavonoid compound, had been reported to exhibit extensive pharmacological effects, but its water solubility and oral bioavailability are only~46±6 µg/mL and 5.8%, respectively. The purpose of this study is to design and develop NRG-loaded solid lipid nanoparticles (NRG-SLNs) to provide prolonged and sustained drug release, with improved stability, involving nontoxic nanocarriers, and increase the bioavailability by means of pulmonary administration. Initially, a group contribution method was used to screen the best solid lipid matrix for the preparation of SLNs. NRG-SLNs were prepared by an emulsification and low-temperature solidification method and optimized using an orthogonal experiment approach. The morphology was examined by transmission electron microscopy, and the particle size and zeta potential were determined by photon correlation spectroscopy. The total drug content of NRG-SLNs was measured by high-performance liquid chromatography, and the encapsulation efficiency (EE) was determined by Sephadex gel-50 chromatography and high-performance liquid chromatography. The in vitro NRG release studies were carried out using a dialysis bag. The best cryoprotectant to prepare NRG-SLN lyophilized powder for future structural characterization was selected using differential scanning calorimetry, powder X-ray diffraction, and Fourier transform infrared spectroscopy. The short-term stability, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay, cellular uptake, and pharmacokinetics in rats were studied after pulmonary administration of NRG-SLN lyophilized powder. Glycerol monostearate was selected to prepare SLNs, and the optimal formulation of NRG-SLNs was spherical in shape, with a particle size of 98 nm, a polydispersity index of 0.258, a zeta potential of -31.4 mV, a total drug content of 9.76 mg, an EE of 79.11%, and a cumulative drug release of 80% in 48 hours with a sustained profile. In addition, 5% mannitol (w
Ji, Peng; Yu, Tong; Liu, Ying; Jiang, Jie; Xu, Jie; Zhao, Ying; Hao, Yanna; Qiu, Yang; Zhao, Wenming; Wu, Chao
Naringenin (NRG), a flavonoid compound, had been reported to exhibit extensive pharmacological effects, but its water solubility and oral bioavailability are only~46±6 µg/mL and 5.8%, respectively. The purpose of this study is to design and develop NRG-loaded solid lipid nanoparticles (NRG-SLNs) to provide prolonged and sustained drug release, with improved stability, involving nontoxic nanocarriers, and increase the bioavailability by means of pulmonary administration. Initially, a group contribution method was used to screen the best solid lipid matrix for the preparation of SLNs. NRG-SLNs were prepared by an emulsification and low-temperature solidification method and optimized using an orthogonal experiment approach. The morphology was examined by transmission electron microscopy, and the particle size and zeta potential were determined by photon correlation spectroscopy. The total drug content of NRG-SLNs was measured by high-performance liquid chromatography, and the encapsulation efficiency (EE) was determined by Sephadex gel-50 chromatography and high-performance liquid chromatography. The in vitro NRG release studies were carried out using a dialysis bag. The best cryoprotectant to prepare NRG-SLN lyophilized powder for future structural characterization was selected using differential scanning calorimetry, powder X-ray diffraction, and Fourier transform infrared spectroscopy. The short-term stability, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay, cellular uptake, and pharmacokinetics in rats were studied after pulmonary administration of NRG-SLN lyophilized powder. Glycerol monostearate was selected to prepare SLNs, and the optimal formulation of NRG-SLNs was spherical in shape, with a particle size of 98 nm, a polydispersity index of 0.258, a zeta potential of −31.4 mV, a total drug content of 9.76 mg, an EE of 79.11%, and a cumulative drug release of 80% in 48 hours with a sustained profile. In addition, 5% mannitol (w
Nabi-Meibodi, Mohsen; Vatanara, Alireza; Najafabadi, Abdolhossein Rouholamini; Rouini, Mohammad Reza; Ramezani, Vahid; Gilani, Kambiz; Etemadzadeh, Seyed Mohammad Hossein; Azadmanesh, Kayhan
Raloxifene HCl (RH), a selective estrogen receptor modulator (SERM), is indicated for the prophylaxis or treatment of postmenopausal osteoporosis. RH shows extremely poor bioavailability due to limited solubility and an extensive intestinal/hepatic first-pass metabolism. Solid lipid nanoparticles (SLNs) are valuable carriers that can enhance drug bioavailability. However, in the case of RH, the encapsulation of the drug in SLNs remains a challenge because of its poor solubility in both water and lipids. In this study, a series of RH-containing SLNs (RH-SLNs) were generated using a modified double emulsion solvent evaporation (DESE) method. Briefly, RH with various drug/lipid ratios was solubilized in the inner core of a double emulsion using different water/organic solvent mixtures. Our best formulation was achieved with the formation of negatively charged nanoparticles, 180nm in diameter, with an encapsulation and loading efficiency of 85% and 4.5%, respectively. It also showed a Fickian mechanism of the drug release in the basic dissolution media. Thermal analysis revealed a distinct decrease in the crystallinity of lipids and RH in comparison with the unprocessed materials. The results of a cell viability assay also showed a better antiproliferative effect of the drug-loaded SLNs versus the free drug solution. Thus, these results indicated that the modified DESE method could be proposed for the effective encapsulation of RH in SLNs with appropriate physicochemical and biological properties.
Madureira, Ana Raquel; Nunes, Sara; Campos, Débora A; Fernandes, João C; Marques, Cláudia; Zuzarte, Monica; Gullón, Beatriz; Rodríguez-Alcalá, Luís M; Calhau, Conceição; Sarmento, Bruno; Gomes, Ana Maria; Pintado, Maria Manuela; Reis, Flávio
Rosmarinic acid (RA) possesses several protective bioactivities that have attracted increasing interest by nutraceutical/pharmaceutical industries. Considering the reduced bioavailability after oral use, effective (and safe) delivery systems are crucial to protect RA from gastrointestinal degradation. This study aims to characterize the safety profile of solid lipid nanoparticles produced with Witepsol and Carnauba waxes and loaded with RA, using in vitro and in vivo approaches, focused on genotoxicity and cytotoxicity assays, redox status markers, hematological and biochemical profile, liver and kidney function, gut bacterial microbiota, and fecal fatty acids composition. Free RA and sage extract, empty nanoparticles, or nanoparticles loaded with RA or sage extract (0.15 and 1.5 mg/mL) were evaluated for cell (lymphocytes) viability, necrosis and apoptosis, and antioxidant/prooxidant effects upon DNA. Wistar rats were orally treated for 14 days with vehicle (control) and with Witepsol or Carnauba nanoparticles loaded with RA at 1 and 10 mg/kg body weight/d. Blood, urine, feces, and several tissues were collected for analysis. Free and loaded RA, at 0.15 mg/mL, presented a safe profile, while genotoxic potential was found for the higher dose (1.5 mg/mL), mainly by necrosis. Our data suggest that both types of nanoparticles are safe when loaded with moderate concentrations of RA, without in vitro genotoxicity and cytotoxicity and with an in vivo safety profile in rats orally treated, thus opening new avenues for use in nutraceutical applications.
Madureira, Ana Raquel; Nunes, Sara; Campos, Débora A; Fernandes, João C; Marques, Cláudia; Zuzarte, Monica; Gullón, Beatriz; Rodríguez-Alcalá, Luís M; Calhau, Conceição; Sarmento, Bruno; Gomes, Ana Maria; Pintado, Maria Manuela; Reis, Flávio
Rosmarinic acid (RA) possesses several protective bioactivities that have attracted increasing interest by nutraceutical/pharmaceutical industries. Considering the reduced bioavailability after oral use, effective (and safe) delivery systems are crucial to protect RA from gastrointestinal degradation. This study aims to characterize the safety profile of solid lipid nanoparticles produced with Witepsol and Carnauba waxes and loaded with RA, using in vitro and in vivo approaches, focused on genotoxicity and cytotoxicity assays, redox status markers, hematological and biochemical profile, liver and kidney function, gut bacterial microbiota, and fecal fatty acids composition. Free RA and sage extract, empty nanoparticles, or nanoparticles loaded with RA or sage extract (0.15 and 1.5 mg/mL) were evaluated for cell (lymphocytes) viability, necrosis and apoptosis, and antioxidant/prooxidant effects upon DNA. Wistar rats were orally treated for 14 days with vehicle (control) and with Witepsol or Carnauba nanoparticles loaded with RA at 1 and 10 mg/kg body weight/d. Blood, urine, feces, and several tissues were collected for analysis. Free and loaded RA, at 0.15 mg/mL, presented a safe profile, while genotoxic potential was found for the higher dose (1.5 mg/mL), mainly by necrosis. Our data suggest that both types of nanoparticles are safe when loaded with moderate concentrations of RA, without in vitro genotoxicity and cytotoxicity and with an in vivo safety profile in rats orally treated, thus opening new avenues for use in nutraceutical applications. PMID:27536103
Siddiqui, Akhtar; Alayoubi, Alaadin; Nazzal, Sami
The objective of this study was to investigate the effect of cetyl alcohol (CA) and Tween® 60 (polysorbate), the primary components of emulsifying wax, on the size, zeta potential and stability of cetyltrimethyl ammonium bromide (CTAB)-based solid lipid nanoparticles (SLN) by D-optimal mixture design. A binary CTAB/polysorbate surfactant blend did not offer an advantage over a simple CTAB-stabilized SLN. This led to the conclusion that emulsifying wax could be readily substituted with CA in simple SLNs based on binary CTAB/CA blends. Polysorbate, however, may be added as a co-emulsifier to adjust the physical properties of the nanoparticles, as dictated by the formulator.
Rahman, Mohamed Habibur; Ramanathan, Muthiah; Sankar, Veintramuthu
Curcumin (diferuloylmethane) possesses low bioavailability due to its poor solubility, permeability and rapid metabolism. Solid Lipid Nanoparticle of curcumin was prepared by high-speed homogenization technique. Stearic acid was used as a lipid, tween 80 as surfactant and various co surfactants were used for the preparation of SLN. The prepared SLN was characterized using zeta sizer, TEM analysis and the average particle size was found to be in the range of 80 nm - 200nm. The entrapment efficiency of the SLN was ~58 to 85%. The characteristic FTIR peaks suggest that the stearic acid is compatible with curcumin. MTT assay was performed on the optimized formulation and the results are indicative that curcumin SLN showed better cytotoxicity in low dose while compared to plain curcumin. The developed Cu-SLN can find its better place in the anticancer therapy.
Durán-Lobato, Matilde; Enguix-González, Alicia; Fernández-Arévalo, Mercedes; Martín-Banderas, Lucía
Lipid nanoparticles (LNPs) are a promising carrier for all administration routes due to their safety, small size, and high loading of lipophilic compounds. Among the LNP production techniques, the easy scale-up, lack of organic solvents, and short production times of the high-pressure homogenization technique (HPH) make this method stand out. In this study, a statistical analysis was applied to the production of LNP by HPH. Spherical LNPs with mean size ranging from 65 nm to 11.623 μm, negative zeta potential under -30 mV, and smooth surface were produced. Manageable equations based on commonly used parameters in the pharmaceutical field were obtained. The lipid to emulsifier ratio ( R L/S) was proved to statistically explain the influence of oil phase and surfactant concentration on final nanoparticles size. Besides, the homogenization pressure was found to ultimately determine LNP size for a given R L/S, while the number of passes applied mainly determined polydispersion. α-Tocopherol was used as a model drug to illustrate release properties of LNP as a function of particle size, which was optimized by the regression models. This study is intended as a first step to optimize production conditions prior to LNP production at both laboratory and industrial scale from an eminently practical approach, based on parameters extensively used in formulation.
Grillone, Agostina; Riva, Eugenio Redolfi; Mondini, Alessio; Forte, Claudia; Calucci, Lucia; Innocenti, Claudia; de Julian Fernandez, Cesar; Cappello, Valentina; Gemmi, Mauro; Moscato, Stefania; Ronca, Francesca; Sacco, Rodolfo; Mattoli, Virgilio; Ciofani, Gianni
Sorafenib is an anticancer drug approved by the Food and Drug Administration for the treatment of hepatocellular and advanced renal carcinoma. The clinical application of sorafenib is promising, yet limited by its severe toxic side effects. The aim of this study is to develop sorafenib-loaded magnetic nanovectors able to enhance the drug delivery to the disease site with the help of a remote magnetic field, thus enabling cancer treatment while limiting negative effects on healthy tissues. Sorafenib and superparamagnetic iron oxide nanoparticles are encapsulated in solid lipid nanoparticles by a hot homogenization technique using cetyl palmitate as lipid matrix. The obtained nanoparticles (Sor-Mag-SLNs) have a sorafenib loading efficiency of about 90% and are found to be very stable in an aqueous environment. Plain Mag-SLNs exhibit good cytocompatibility, whereas an antiproliferative effect against tumor cells (human hepatocarcinoma HepG2) is observed for drug-loaded Sor-Mag-SLNs. The obtained results show that it is possible to prepare stable Sor-Mag-SLNs able to inhibit cancer cell proliferation through the sorafenib cytotoxic action, and to enhance/localize this effect in a desired area thanks to a magnetically driven accumulation of the drug. Moreover, the relaxivity properties observed in water suspensions hold promise for Sor-Mag-SLN tracking through clinical magnetic resonance imaging.
Cho, Hyun-Jong; Park, Jin Woo; Yoon, In-Soo; Kim, Dae-Duk
Docetaxel is a potent anticancer drug, but development of an oral formulation has been hindered mainly due to its poor oral bioavailability. In this study, solid lipid nanoparticles (SLNs) surface-modified by Tween 80 or D-alpha-tocopheryl poly(ethylene glycol 1000) succinate (TPGS 1000) were prepared and evaluated in terms of their feasibility as oral delivery systems for docetaxel. Tween 80-emulsified and TPGS 1000-emulsified tristearin-based lipidic nanoparticles were prepared by a solvent-diffusion method, and their particle size distribution, zeta potential, drug loading, and particle morphology were characterized. An in vitro release study showed a sustained-release profile of docetaxel from the SLNs compared with an intravenous docetaxel formulation (Taxotere®). Tween 80-emulsified SLNs showed enhanced intestinal absorption, lymphatic uptake, and relative oral bioavailability of docetaxel compared with Taxotere in rats. These results may be attributable to the absorption-enhancing effects of the tristearin nanoparticle. Moreover, compared with Tween 80-emulsified SLNs, the intestinal absorption and relative oral bioavailability of docetaxel in rats were further improved in TPGS 1000-emulsified SLNs, probably due to better inhibition of drug efflux by TPGS 1000, along with intestinal lymphatic uptake. Taken together, it is worth noting that these surface-modified SLNs may serve as efficient oral delivery systems for docetaxel. PMID:24531717
Madureira, Ana Raquel; Campos, Débora A; Oliveira, Ana; Sarmento, Bruno; Pintado, Maria Manuela; Gomes, Ana Maria
The evaluation of the digestion effects on bioactive solid lipid nanoparticles (SLN) was performed. For this purpose, witepsol and carnauba SLN loaded with rosmarinic acid (RA) were exposed to the simulated gastrointestinal tract (GIT) conditions prevailing in stomach and small intestine. The simulation of intestinal epithelium was made with a dialysis bag and intestinal cell culture lines. Changes on SLN physical properties, RA release and absorption profiles were followed at each step. Combination of digestion pH and enzymes showed a significant effect upon SLN physical properties. Zeta potential values increased at stomach conditions and decreased at small intestine simulation. Also, at intestine, SLN increased their sizes and released 40-60% of RA, maintaining its initial antioxidant activity values. Sustained release of 40% of RA from SLN was also observed in dialysis tube. At CaCo-2 cell line, both types of SLN showed similar absorbed RA % (ca. 30%). Nevertheless, in CaCo-2/HT29x mix cell lines, for carnauba SLN a lower adsorption RA % was observed than for witepsol SLN. Solid lipid nanoparticles protected RA bioactivity (in terms of antioxidant activity) until reaching the intestine. A controlled release of RA from SLN was achieved and a significant absorption was observed at intestinal cells. Overall, SLN produced with witepsol showed a higher stability than carnauba SLN.
Taylor, Erik N.; Kummer, Kim M.; Dyondi, Deepti; Webster, Thomas J.; Banerjee, Rinti
Infections are both frequent and costly in hospitals around the world, leading to longer hospital stays, overuse of antibiotics, and excessive costs to the healthcare system. Moreover, antibiotic resistant organisms, such as Pseudomonas aeruginosa are increasing in frequency, leading to 1.7 million infections per year in USA hospitals, and 99 000 deaths, both due to the evolution of antibiotic resistance and the formation of biofilms on medical devices. In particular, respiratory infections are costly, deadly to 4.5 million persons per year worldwide, and can spread to the lungs through the placement of endotracheal tubing. In this study, towards a reduction in infections, solid lipid nanoparticles were formulated from free fatty acids, or natural lipophilic constituents found in tissues of the body. A strategy was developed to target infections by producing coatings made of non-toxic chemistries lauric acid and oleic acid delivered by core-shell solid lipid nanoparticles that act against bacteria by multiple mechanisms at the nanoscale, including disruption of bacteria leading to DNA release, and reducing the adhesion of dead bacteria to ~1%. This is the first such study to explore an anti-infection surface relying on these multi-tier strategies at the nanoscale.
Zhou, Yan; Zhang, Guoqiang; Rao, Zhi; Yang, Yang; Zhou, Qian; Qin, Hongyan; Wei, Yuhui; Wu, Xin'an
Venlafaxine (VLX) could be pumped out of the brain by P-glycoprotein (P-gp). Moreover, the expression of P-gp distributed in blood-brain barrier could be significantly induced by VLX. Thus, P-gp could be considered as the nature barrier for delivering of VLX to the brain. The aim of this study was to investigate whether the efflux function and increased expression of P-gp could be reversed by utilizing solid lipid nanoparticles (SLN). VLX solid lipid nanoparticles (VLX - SLN) were prepared and evaluated. Pharmacokinetics and brain distribution of VLX in different formulations were conducted after oral or intravenous administration. P-gp efflux function to VLX was evaluated by the brain uptake amount of VLX, while P-gp expression was investigated by Western blotting. Results indicated that the entrapment, mean size and zata potential of VLX - SLN was 74.9 ± 3.0 %, 186.3 ± 69.26 nm and -22.8 ± 7.78 mv, respectively. After vein injection of VLX formulations, the brain uptake amount of VLX from VLX - SLN was significantly higher than that of VLX solution, VLX solution with empty SLN (VLX+ empty SLN) and VLX solution with Verapamil (VLX + Ver), respectively. Furthermore, the protein mass of P-gp in VLX - SLN treated group was the lowest among all the investigated groups. These results indicated that SLN could overcome P-gp and achieve brain target by intravenous administration.
Bhalekar, Mangesh; Upadhaya, Prashant; Madgulkar, Ashwini
Darunavir, an anti-HIV drug having poor solubility in aqueous and lipid medium, illustrates degradation above its melting point, i.e. 74 °C, thus, posing a challenge to dosage formulation. Despite, the drug suffers from poor oral bioavailability (37%) owing to less permeability and being poly-glycoprotein and cyp3A metabolism substrate. The study aimed formulating a SLN system to overcome the formulation and bioavailability associated problems of the drug. Based on the drug solubility and stable dispersion findings, lipid and surfactant were chosen and nanoparticles were prepared using hot-homogenization technique. Optimization of variables such as lipid concentration, oil-surfactant and homogenization cycle was carried and their effect on particle size and entrapment efficiency was studied. Freeze-dried SLN further characterized using SEM, DSC and PXRD analysis revealed complete entrapment of the drug and amorphous nature of the SLN. In vitro pH release studies in 0.1 N HCl and 6.8 pH buffer demonstrated 84 and 80% release at the end of 12th h. The apparent permeability of the SLN across rat intestine was found to be 24 × 10-6 at 37 °C at the end of 30 min while at 4 °C the same was found to be 5.6 × 10-6 prompting involvement of endocytic processes in the uptake of SLN. Accelerated stability studies revealed no prominent changes upon storage.
Silva, A C; Amaral, M H; González-Mira, E; Santos, D; Ferreira, D
Two different solid lipid nanoparticles (SLN)-based hydrogels (HGs) formulations were developed as potential mucoadhesive systems for risperidone (RISP) oral transmucosal delivery. The suitability of the prepared semi-solid formulations for application on oral mucosa was assessed by means of rheological and textural analysis, during 30 days. Plastic flows with thixotropy and high adhesiveness were obtained for all the tested systems, which predict their success for the oral transmucosal application proposed. The SLN remained within the colloidal range after HGs preparation. However, after 30 days of storage, a particle size increase was detected in one type of the HGs formulations. In vitro drug release studies revealed a more pronounced RISP release after SLN hydrogel entrapment, when compared to the dispersions alone. In addition, a pH-dependent release was observed as well. The predicted in vivo RISP release mechanism was Fickian diffusion alone or combined with erosion.
de Oliveira, Jhones Luiz; Campos, Estefânia Vangelie Ramos; Gonçalves da Silva, Camila Morais; Pasquoto, Tatiane; Lima, Renata; Fraceto, Leonardo Fernandes
Solid lipid nanoparticles (SLN) containing the herbicides atrazine and simazine were prepared and characterized, and in vitro evaluation was made of the release kinetics, herbicidal activity, and cytotoxicity. The stability of the nanoparticles was investigated over a period of 120 days, via analyses of particle size, ζ potential, polydispersion, pH, and encapsulation efficiency. SLN showed good physicochemical stability and high encapsulation efficiencies. Release kinetics tests showed that use of SLN modified the release profiles of the herbicides in water. Herbicidal activity assays performed with pre- and postemergence treatment of the target species Raphanus raphanistrum showed the effectiveness of the formulations of nanoparticles containing herbicides. Assays with nontarget organisms (Zea mays) showed that the formulations did not affect plant growth. The results of cytotoxicity assays indicated that the presence of SLN acted to reduce the toxicity of the herbicides. The new nanoparticle formulations enable the use of smaller quantities of herbicide and therefore offer a more environmentally friendly method of controlling weeds in agriculture.
Uner, M; Wissing, S A; Yener, G; Müller, R H
This study was performed as a complimentary to our previous study regarding the chemical stability of ascorbyl palmitate (AP) in solid lipid nanoparticles (SLN), nanostructured lipid carriers (NLC) and for comparison, in nanoemulsion (NE) incorporated into a hydrogel produced by high pressure homogenization. AP is known as an effective antioxidant that protects tissue integrity similar to vitamin C. Recently, its moisturizing activity in conventional topical formulations was found to be high. The aim of the present study was to investigate the moisturizing potential of AP in SLN and NLC incorporated into hydrogel as colloidal carrier systems. It has been known that SLN and NLC have occlusive effects, but AP incorporation moisturized skin significantly better than placebo in short-term (p < 0.001) and long-term trials (p < 0.01) for both SLN and NLC. In the second part of the study, SLN and NLC were found to sustain the penetration of AP through excised human skin about 1/2 and 2/3 times compared to NE (p < 0.001 and p < 0.01), respectively, due to the solid state of Witepsol E85 in the lipid phase.
Liu, Jingwen; Meng, Tingting; Yuan, Ming; Wen, Lijuan; Cheng, Bolin; Liu, Na; Huang, Xuan; Hong, Yun; Yuan, Hong; Hu, Fuqiang
Background One of the major obstacles in the treatment of breast cancer is breast cancer stem cells (BCSC) which are resistant to standard chemotherapeutic drugs. It has been proven that microRNA-200c (miR-200c) can restore sensitivity to microtubule-targeting chemotherapeutic drugs by reducing the expression of class III β-tubulin. In this study, combination therapy with miR-200c and paclitaxel (PTX) mediated by lipid nanoparticles was investigated as an alternative strategy against BCSC. Materials and methods A cationic lipid 1,2-dioleoyl-3-trimethylammonium-propane was strategically selected to formulate solid lipid nanoparticles (SLN) for miR-200c delivery. Nanostructured lipid carriers (NLC) with 20 wt% oleic acid were prepared for PTX delivery. Mammospheres, which gained the characteristics of BCSC, were used as a cell model to evaluate the efficiency of combination therapy. Results The cationic SLN could condense anionic miRNA to form SLN/miRNA complexes via charge interactions and could protect miRNA from degradation by ribonuclease. SLN/miR-200c complexes achieved 11.6-fold expression of miR-200c after incubation for 24 hours, compared with that of Lipofectamine™ 2000/miR-200c complexes (*P<0.05). Intracellular drug release assay proved that miRNA can be released from SLN/miRNA complexes efficiently in 12 hours after cellular uptake. After BCSC were transfected with SLN/miR-200c, the expression of class III β-tubulin was effectively downregulated and the cellular cytotoxicity of PTX-loaded NLC (NLC/PTX) against BCSC was enhanced significantly (**P<0.01). Conclusion The results indicated that the cationic SLN could serve as a promising carrier for miRNA delivery. In addition, the combination therapy of miR-200c and PTX revealed a novel therapeutic strategy for the treatment of BCSC. PMID:28003747
Emami, J.; Mohiti, H.; Hamishehkar, H.; Varshosaz, J.
Budesonide is a potent non-halogenated corticosteroid with high anti-inflammatory effects. The lungs are an attractive route for non-invasive drug delivery with advantages for both systemic and local applications. The aim of the present study was to develop, characterize and optimize a solid lipid nanoparticle system to deliver budesonide to the lungs. Budesonide-loaded solid lipid nanoparticles were prepared by the emulsification-solvent diffusion method. The impact of various processing variables including surfactant type and concentration, lipid content organic and aqueous volume, and sonication time were assessed on the particle size, zeta potential, entrapment efficiency, loading percent and mean dissolution time. Taguchi design with 12 formulations along with Box-Behnken design with 17 formulations was developed. The impact of each factor upon the eventual responses was evaluated, and the optimized formulation was finally selected. The size and morphology of the prepared nanoparticles were studied using scanning electron microscope. Based on the optimization made by Design Expert 7® software, a formulation made of glycerol monostearate, 1.2 % polyvinyl alcohol (PVA), weight ratio of lipid/drug of 10 and sonication time of 90 s was selected. Particle size, zeta potential, entrapment efficiency, loading percent, and mean dissolution time of adopted formulation were predicted and confirmed to be 218.2 ± 6.6 nm, -26.7 ± 1.9 mV, 92.5 ± 0.52 %, 5.8 ± 0.3 %, and 10.4 ± 0.29 h, respectively. Since the preparation and evaluation of the selected formulation within the laboratory yielded acceptable results with low error percent, the modeling and optimization was justified. The optimized formulation co-spray dried with lactose (hybrid microparticles) displayed desirable fine particle fraction, mass median aerodynamic diameter (MMAD), and geometric standard deviation of 49.5%, 2.06 μm, and 2.98 μm; respectively. Our results provide fundamental data for the
Severino, Patrícia; Andreani, Tatiana; Jäger, Alessandro; Chaud, Marco V; Santana, Maria Helena A; Silva, Amélia M; Souto, Eliana B
Insulin was used as model protein to developed innovative Solid Lipid Nanoparticles (SLNs) for the delivery of hydrophilic biotech drugs, with potential use in medicinal chemistry. SLNs were prepared by double emulsion with the purpose of promoting stability and enhancing the protein bioavailability. Softisan(®)100 was selected as solid lipid matrix. The surfactants (Tween(®)80, Span(®)80 and Lipoid(®)S75) and insulin were chosen applying a 2(2) factorial design with triplicate of central point, evaluating the influence of dependents variables as polydispersity index (PI), mean particle size (z-AVE), zeta potential (ZP) and encapsulation efficiency (EE) by factorial design using the ANOVA test. Therefore, thermodynamic stability, polymorphism and matrix crystallinity were checked by Differential Scanning Calorimetry (DSC) and Wide Angle X-ray Diffraction (WAXD), whereas the effect of toxicity of SLNs was check in HepG2 and Caco-2 cells. Results showed a mean particle size (z-AVE) width between 294.6 nm and 627.0 nm, a PI in the range of 0.425-0.750, ZP about -3 mV, and the EE between 38.39% and 81.20%. After tempering the bulk lipid (mimicking the end process of production), the lipid showed amorphous characteristics, with a melting point of ca. 30 °C. The toxicity of SLNs was evaluated in two distinct cell lines (HEPG-2 and Caco-2), showing to be dependent on the concentration of particles in HEPG-2 cells, while no toxicity in was reported in Caco-2 cells. SLNs were stable for 24 h in in vitro human serum albumin (HSA) solution. The resulting SLNs fabricated by double emulsion may provide a promising approach for administration of protein therapeutics and antigens.
Xue, Mei; Zhang, Liang; Yang, Ming-xing; Zhang, Wei; Li, Xiu-min; Ou, Zhi-min; Li, Zhi-peng; Liu, Su-huan; Li, Xue-jun; Yang, Shu-yu
Berberine (BBR) shows very low plasma levels after oral administration due to its poor absorption by the gastrointestinal tract. We have previously demonstrated that BBR showed increased gastrointestinal absorption and enhanced antidiabetic effects in db/db mice after being entrapped into solid lipid nanoparticles (SLNs). However, whether BBR-loaded SLNs (BBR-SLNs) also have beneficial effects on hepatosteatosis is not clear. We investigated the effects of BBR-SLNs on lipid metabolism in the liver using histological staining and reverse transcription polymerase chain reaction analysis. The results showed that oral administration of BBR-SLNs inhibited the increase of body weight and decreased liver weight in parallel with the reduction of serum alanine transaminase and liver triglyceride levels in db/db mice. The maximum drug concentration in the liver was 20-fold higher than that in the blood. BBR-SLNs reduced fat accumulation and lipid droplet sizes significantly in the liver, as indicated by hematoxylin and eosin and Oil Red O staining. The expression of lipogenic genes, including fatty acid synthase (FAS), stearoyl-CoA desaturase (SCD1), and sterol regulatory element-binding protein 1c (SREBP1c) were downregulated, while lipolytic gene carnitine palmitoyltransferase-1 (CPT1) was upregulated in BBR-SLN-treated livers. In summary, we have uncovered an unexpected effect of BBR-SLNs on hepatosteatosis treatment through the inhibition of lipogenesis and the induction of lipolysis in the liver of db/db mice.
Aljaeid, Bader Mubarak; Hosny, Khaled Mohamed
Background and objective Miconazole is a broad-spectrum antifungal drug that has poor aqueous solubility (<1 µg/mL); as a result, a reduction in its therapeutic efficacy has been reported. The aim of this study was to formulate and evaluate miconazole-loaded solid lipid nanoparticles (MN-SLNs) for oral administration to find an innovative way to alleviate the disadvantages associated with commercially available capsules. Methods MN-SLNs were prepared by hot homogenization/ultrasonication. The solubility of miconazole in different solid lipids was measured. The effect of process variables, such as surfactant types, homogenization and ultrasonication times, and the charge-inducing agent on the particle size, zeta potential, and encapsulation efficiency were determined. Furthermore, in vitro drug release, antifungal activity against Candida albicans, and in vivo pharmacokinetics were studied in rabbits. Results The MN-SLN, consisting of 1.5% miconazole, 2% Precirol ATO5, 2.5% Cremophor RH40, 0.5% Lecinol, and 0.1% Dicetylphosphate, had an average diameter of 23 nm with a 90.2% entrapment efficiency. Furthermore, the formulation of MN-SLNs enhanced the antifungal activity compared with miconazole capsules. An in vivo pharmacokinetic study revealed that the bioavailability was enhanced by >2.5-fold. Conclusion MN-SLN was more efficient in the treatment of candidiasis with enhanced oral bioavailability and could be a promising carrier for the oral delivery of miconazole. PMID:26869787
Montasser, Imed; Shahgaldian, Patrick; Perret, Florent; Coleman, Anthony W.
Solid lipid nanoparticles (SLNs) have attracted increasing attention during recent years. This paper presents an overview about the use of calix[n]arenes and calix-resorcinarenes in the formulation of SLNs. Because of their specific inclusion capability both in the intraparticle spaces and in the host cavities as well as their capacity for functionalization, these colloidal nanostructures represent excellent tools for the encapsulation of different active pharmaceutical ingredients (APIs) in the area of drug targeting, cosmetic additives, contrast agents, etc. Various synthetic routes to the supramolecular structures will be given. These various routes lead to the formulation of the corresponding SLNs. Characterization, properties, toxicological considerations as well as numerous corresponding experimental studies and analytical methods will be also exposed and discussed. PMID:24196356
Dang, Hao; Meng, Murtaza Hasan Weiwei; Zhao, Haiwei; Iqbal, Javed; Dai, Rongji; Deng, Yulin; Lv, Fang
Luteolin (LU, 5,7,3',4'-tetrahydroxyflavone) most active compound in Chinese herbal flavones has been acting as a antimicrobial, anti-inflammatory, anti-cancer, and antimutagen. However, its poor bioavailability, hydrophobicity, and pharmacokinetics restrict clinical application. Here in this study, LU-loaded solid lipid nanoparticles have been prepared by hot-microemulsion ultrasonic technique to improve the bioavailability & pharmacokinetics of compound. LU-loaded solid lipid nanoparticle size was confirmed by particle size analyzer with range from 47 to 118 nm, having zepta potential -9.2 mV and polydisperse index 0.247, respectively. Round-shaped SLNPs were obtained by using transmission electron microscope, and encapsulation efficiency 74.80 % was calculated by using HPLC. Both in vitro and vivo studies, LC-MS/MS technique was used for quantification of Luteolin in rat. The T max value of drug with LU-SLNs after the administration was Ten times shorter than pure Luteolin suspension administration. C max value of drug after the administration of LU-SLNs was five times higher than obtained with native drug suspension. Luteolin with SLNs has increased the half-life approximately up to 2 h. Distribution and clearance of drug with SLNs were significantly decreased by 2.16-10.57 fold, respectively. In the end, the relative bioavailability of SLNs has improved about 4.89 compared to Luteolin with SLNs. From this study, it can be concluded that LU-SLNs have not only great potential for improving solubility but also increased the drug concentration in plasma. Furthermore, use of LC-MS/MS for quantification of LU-SLNs in rat plasma is reliable and of therapeutic usefulness, especially for neurodegenerative and cancerous disorders in humans.
Polchi, Alice; Magini, Alessandro; Mazuryk, Jarosław; Tancini, Brunella; Gapiński, Jacek; Patkowski, Adam; Giovagnoli, Stefano; Emiliani, Carla
Recently, the use of mammalian target of rapamycin (mTOR) inhibitors, in particular rapamycin (Rp), has been suggested to improve the treatment of neurodegenerative diseases. However, as Rp is a strong immunosuppressant, specific delivery to the brain has been postulated to avoid systemic exposure. In this work, we fabricated new Rp loaded solid lipid nanoparticles (Rp-SLN) stabilized with polysorbate 80 (PS80), comparing two different methods and lipids. The formulations were characterized by differential scanning calorimetry (DSC), nuclear magnetic resonance (NMR), wide angle X-ray scattering (WAXS), cryo-transmission electron microscopy (cryo-TEM), dynamic light scattering (DLS) and particle tracking. In vitro release and short-term stability were assessed. Biological behavior of Rp-SLN was tested in SH-SY5Y neuroblastoma cells. The inhibition of mTOR complex 1 (mTORC1) was evaluated over time by a pulse-chase study compared to free Rp and Rp nanocrystals. Compritol Rp-SLN resulted more stable and possessing proper size and surface properties with respect to cetyl palmitate Rp-SLN. Rapamycin was entrapped in an amorphous form in the solid lipid matrix that showed partial crystallinity with stable Lβ, sub-Lα and Lβ′ arrangements. PS80 was stably anchored on particle surface. No drug release was observed over 24 h and Rp-SLN had a higher cell uptake and a more sustained effect over a week. The mTORC1 inhibition was higher with Rp-SLN. Overall, compritol Rp-SLN show suitable characteristics and stability to be considered for further investigation as Rp brain delivery system.
Rodenak-Kladniew, Boris; Islan, German A; de Bravo, Margarita G; Durán, Nelson; Castro, Guillermo R
Linalool (LN) is a monoterpene found in essential oils of plants and herbs that produces multiple effects on the mevalonate pathway and interesting antiproliferative activity in cancer cells. However, due to its poor aqueous solubility, an efficient vehicle is needed to improve its administration and bioavailability in physiological media. LN encapsulation in solid lipid nanoparticles (SLN) with different compositions was explored and in vitro tested in two cancer cell lines. SLN of myristyl myristate (MM), cetyl esters (SS) and cetyl palmitate (CP) were prepared by sonication in the presence of Pluronic(®)F68 as surfactant. Nanoparticle size, morphology and distribution were determined by dynamic light scattering in combination with optical and transmission electron microscopy (TEM). SLN showed spherical shape and mean diameters in the range of 90-130nm with narrow size dispersion (PDI values lower than 0.2) and Z potentials around -4.0mV. The encapsulation percentages of LN in SLN were higher than 80% for all tested formulations and exhibited in vitro LN controlled release profiles for at least 72h. The nanoparticles were physicochemically characterized by FTIR, XRD, DSC and TGA, and the incorporation of LN into SLN was higher than 80% in tested matrices. The developed formulations, and in particular SLN (MM)-LN, showed in vitro antiproliferative effects on hepatocarcinoma (HepG2) and lung adenocarcinoma (A549) cell lines in a dose-dependent response, and higher inhibitory effects were found in comparison with free LN. The cellular uptake of SLN was demonstrated by fluorescence microscopy, enhancing the ability of nanoparticles to intracellularly deliver the cargo molecules.
Anantachaisilp, Suranan; Meejoo Smith, Siwaporn; Treetong, Alongkot; Pratontep, Sirapat; Puttipipatkhachorn, Satit; Rungsardthong Ruktanonchai, Uracha
Lipid nanoparticles are a promising alternative to existing carriers in chemical or drug delivery systems. A key challenge is to determine how chemicals are incorporated and distributed inside nanoparticles, which assists in controlling chemical retention and release characteristics. This study reports the chemical and structural investigation of γ-oryzanol loading inside a model lipid nanoparticle drug delivery system composed of cetyl palmitate as solid lipid and Miglyol 812® as liquid lipid. The lipid nanoparticles were prepared by high pressure homogenization at varying liquid lipid content, in comparison with the γ-oryzanol free systems. The size of the lipid nanoparticles, as measured by the photon correlation spectroscopy, was found to decrease with increased liquid lipid content from 200 to 160 nm. High-resolution proton nuclear magnetic resonance (1H-NMR) measurements of the medium chain triglyceride of the liquid lipid has confirmed successful incorporation of the liquid lipid in the lipid nanoparticles. Differential scanning calorimetric and powder x-ray diffraction measurements provide complementary results to the 1H-NMR, whereby the crystallinity of the lipid nanoparticles diminishes with an increase in the liquid lipid content. For the distribution of γ-oryzanol inside the lipid nanoparticles, the 1H-NMR revealed that the chemical shifts of the liquid lipid in γ-oryzanol loaded systems were found at rather higher field than those in γ-oryzanol free systems, suggesting incorporation of γ-oryzanol in the liquid lipid. In addition, the phase-separated structure was observed by atomic force microscopy for lipid nanoparticles with 0% liquid lipid, but not for lipid nanoparticles with 5 and 10% liquid lipid. Raman spectroscopic and mapping measurements further revealed preferential incorporation of γ-oryzanol in the liquid part rather than the solid part of in the lipid nanoparticles. Simple models representing the distribution of γ-oryzanol and
Rassu, Giovanna; Soddu, Elena; Posadino, Anna Maria; Pintus, Gianfranco; Sarmento, Bruno; Giunchedi, Paolo; Gavini, Elisabetta
We designed a delivery system to obtain an efficient and optimal nose-to-brain transport of BACE1 siRNA, potentially useful in the treatment of Alzheimer's disease. We selected a cell-penetrating peptide, the short peptide derived from rabies virus glycoprotein known as RVG-9R, to increase the transcellular pathway in neuronal cells. The optimal molar ratio between RVG-9R and BACE1 siRNA was elucidated. The complex between the two was then encapsulated. We propose chitosan-coated and uncoated solid lipid nanoparticles (SLNs) as a nasal delivery system capable of exploiting both olfactory and trigeminal nerve pathways. The coating process had an effect on the zeta potential, obtaining positively-charged nanoparticles, and on siRNA protection. The positive charge of the coating formulation ensured mucoadhesiveness to the particles and also prolonged residence time in the nasal cavity. We studied the cellular transport of siRNA released from the SLNs using Caco-2 as a model of epithelial-like phenotypes. We found that siRNA permeates the monolayer to a greater extent when released from any of the studied formulations than from bare siRNA, and primarily from chitosan-coated SLNs.
Heidari-Kharaji, Maryam; Taheri, Tahereh; Doroud, Delaram; Habibzadeh, Sima; Rafati, Sima
Leishmaniasis is a parasitic disease transmitted through the bite of an infected phlebotomine sand fly and caused by protozoan parasites of the genus Leishmania. There is no available vaccine for leishmaniasis in human, and the current chemotherapy approaches are hampered by different clinical problems. Most of available drugs are confined to a limited number of toxic chemical compounds, which some parasite strains have evolved drug resistance against. Hence, drug discovery and production of a new anti leishmanial compound is essential. One promising strategy is using the nanoparticle delivery systems with the aim of accelerating the efficacy of the available treatments. In the present study, paromomycin sulfate (PM) was formulated in solid lipid nanoparticles (SLN) and the in vivo efficacy was investigated against Leishmania tropica in BALB/c mice model. To do so, the increase in footpad thickness was measured and real-time PCR was performed to quantify the parasite load after infectious challenge. The level of nitric oxide and cytokines including interleukin-4 (IL-4) and gamma interferon (IFN -γ) were assessed. Altogether, the results show that PM loaded into SLN is significantly more effective than PM alone in inhibiting the parasite propagation and switching towards Th1 response.
Kharaji, Maryam Heidari; Doroud, Delaram; Taheri, Tahereh; Rafati, Sima
Leishmaniasis is a worldwide disease that leads to high mortality and morbidity in human populations. Today, leishmaniasis is managed via drug therapy. The drugs that are already in clinical use are limited to a number of toxic chemical compounds and their parasite drug resistance is increasing. It is therefore essential, in order to circumvent the current difficulties, to design a new anti-leishmanial drug treatment strategy. Besides producing new, active anti-leishmanial entities, another promising strategy could be developing novel delivery systems and formulations of the existing pharmaceutical ingredients to improve drug efficacy. In the present study, paromomycin sulfate (PM), as one of the promising anti-leishmanial drugs, was formulated in solid lipid nanoparticles (SLN), and its in vitro efficacy was investigated against different strains of Leishmania using a MTT test, Parasite-Rescue-Transformation-Assay, SYTO Green staining, and fluorescent microscope imaging. The results show that PM-loaded SLN is significantly more effective than PM in inhibiting parasite propagation (P < 0.05) and that cytotoxicity of PM-SLN formulations is size dependent. According to our results, delivery of the drugs to the macrophages via nanoparticle utilization seems to be an accessible and practical approach.
Kuo, Yung-Chih; Chung, Chiu-Yen
Solid lipid nanoparticles (SLNs) with complex internal phase were fabricated for formulating stavudine (D4T), delavirdine (DLV), and saquinavir (SQV). The lipids including Compritol 888 ATO, tripalmitin, and cacao butter were stabilized by L-α-phospatidylcholine, cholesteryl hemisuccinate, and taurocholate to form SLNs. The results revealed that the morphology of SLNs was spheroidal with shallow surface pits. An increase in the weight percentage of Compritol 888 ATO increased the average diameter of D4T-entrapping SLNs and decreased that of DLV- and SQV-entrapping SLNs. Preservation at 4°C over 6 weeks slightly enhanced the size of SLNs. For a specific drug, an increase in the entrapment efficiency enlarged the nanocarriers. The order of drug in the average particle diameter and in the entrapment efficiency was SQV>DLV>D4T, in general. In addition, the dissolution of the three drugs from SLNs showed the characteristics of sustained release. The order of drug in the cumulative release percentage was D4T>DLV>SQV. SLNs containing Compritol 888 ATO, tripalmitin, and cacao butter are efficient in carrying antiretroviral agents for medicinal application.
Kakkar, Vandita; Kaur, Indu Pal
Aluminium, a well established neurotoxicant, is reported to be involved in the aetiology of Alzheimer's disease (AD) due to its easy admittance and accumulation in central nervous system (CNS). Simultaneous curcumin treatment during the induction of neurotoxicity by AlCl(3) is reported to provide protection. However, the therapeutic potential of curcumin in terms of reversing the neuronal damage once induced is limited due to its compromised bioavailability (BA). We prepared solid lipid nanoparticles of curcumin (C-SLNs) with enhanced BA (32-155 times) and investigated its therapeutic role in alleviating behavioural, biochemical and histochemical changes upon oral administration (100mg/kg) of AlCl(3) in male Lacca mice. Adverse effects of AlCl(3) were completely reversed by oral administration of C-SLNs. Treatment with free curcumin showed ≤ 15% recovery in membrane lipids (LPO) and 22% recovery in acetylcholinesterase (AChE) with respect to AlCl(3) treated group. C-SLNs showed significantly better results (97.46% and 73% recovery in LPO and AChE) at a dose of 50mg/kg, and the results were comparable (p ≤ 0.001) to those achieved with rivastigmine. Histopathology of the brain sections of C-SLNs treated groups also indicated significant improvement. Study highlights the potential of C-SLNs for treatment of AD.
Luo, Yangchao; Teng, Zi; Li, Ying; Wang, Qin
The poor stability of solid lipid nanoparticles (SLN) under acidic condition resulted in large aggregation in gastric environment, limiting their application as oral delivery systems. In this study, a series of SLN was prepared to investigate the effects of surfactant/cosurfactant and chitosan coating on their physicochemical properties as well as cellular uptake. SLN was prepared from Compritol 888 ATO using a low-energy method combining the solvent-diffusion and hot homogenization technique. Poloxamer 188 and polyethylene glycol (PEG) were effective emulsifiers to produce SLN with better physicochemical properties than SLN control. Chitosan-coated SLN exhibited the best stability under acidic condition by forming a thick layer around the lipid core, as clearly observed by transmission electron microscope. The intermolecular interactions in different formulations were monitored by Fourier transform infrared spectroscopy. Chitosan coating also significantly improved the mucoadhesive property of SLN as determined by Quartz Crystal Microbalance. In vitro drug delivery assays, cytotoxicity, and cellular uptake of SLN were studied by incorporating coumarin 6 as a fluorescence probe. Overall, chitosan-coated SLN was superior to other formulations and held promising features for its application as a potential oral drug delivery system for hydrophobic drugs.
Silva, A C; González-Mira, E; García, M L; Egea, M A; Fonseca, J; Silva, R; Santos, D; Souto, E B; Ferreira, D
The suitability of solid lipid nanoparticles (SLN) for the encapsulation of risperidone (RISP), an antipsychotic lipophilic drug, was assessed for oral administration. The hot high pressure homogenization (HPH) and the ultrasound (US) technique were used as production methods for SLN. All the studies on the SLN formulations were done in parallel, in order to compare the results and conclude about the advantages and limitations of both techniques. The particle sizes were in the nanometer range for all prepared SLN formulations and the zeta potential absolute values were high, predicting good long-term stability. Optical analyses demonstrated the achievement of stable colloidal dispersions. Physicochemical characterization of dispersions and bulk lipids, performed by differential scanning calorimetry (DSC) and X-ray assays, support prediction of occurrence of drug incorporation in the SLN and good long term stability of the systems. The toxicity of SLN with Caco-2 cells and the existence of contaminations derived from the production equipments were assessed by the (4,5-dimethylthiazol-2-yl)2,5-diphenyl-tetrazolium bromide (MTT) assay. The results showed 90% of cell viability after SLN exposure, with no significant differences within all prepared formulations (p > 0.05). From this study, we conclude that SLN can be considered as efficient carriers for RISP encapsulation. Moreover, HPH and US revealed to be both effective methods for SLN production.
Lai, Francesco; Wissing, Sylvia A; Müller, Rainer H; Fadda, Anna M
The aim of this study was to formulate a new delivery system for ecological pesticides by the incorporation of Artemisia arborescens L essential oil into solid lipid nanoparticles (SLN). Two different SLN formulations were prepared following the high-pressure homogenization technique using Compritol 888 ATO as lipid and Poloxamer 188 or Miranol Ultra C32 as surfactants. The SLN formulation particle size was determined using Photon correlation spectroscopy (PCS) and laser diffraction analysis (LD). The change of particle charge was studied by zeta potential (ZP) measurements, while the melting and recrystallization behavior was studied using differential scanning calorimetry (DSC). In vitro release studies of the essential oil were performed at 35 degrees C. Data showed a high physical stability for both formulations at various storage temperatures during 2 months of investigation. In particular, average diameter of Artemisia arborescens L essential oil-loaded SLN did not vary during storage and increased slightly after spraying the SLN dispersions. In vitro release experiments showed that SLN were able to reduce the rapid evaporation of essential oil if compared with the reference emulsions. Therefore, obtained results showed that the studied SLN formulations are suitable carriers in agriculture.
Mosallaei, Navid; Mahmoudi, Asma; Ghandehari, Hamidreza; Yellepeddi, Venkata Kashyap; Jaafari, Mahmoud Reza; Malaekeh-Nikouei, Bizhan
7-Ethyl-10-hydroxycamptothecin (SN38) is a biologically active metabolite of irinotecan. Due to the variability of irinotecan metabolism rate to SN38, and poor solubility of this compound in pharmaceutically acceptable solvents, SN38 has not been successfully used in the clinic. In the present study, we prepared solid lipid nanoparticle (SLN) formulations containing SN38 and evaluated the in vitro and in vivo efficacy of these nanoparticles. SLNs and PEGylated SLNs containing SN38 (SLN-SN38 and PEG-SLN-SN38) were prepared using ultrasonication technique. Nanoparticles were characterized for size, zeta potential, and drug encapsulation efficiency. In vitro cytotoxicity of these compounds was evaluated in two colorectal carcinoma cell lines, namely C-26 and HT-116. In vivo antitumor efficacy of the formulations was evaluated in C-26 xenograft tumor mice models. Mice survival was also explored through 60days post IV injection. Mean size of SLN-SN38 and PEG-SLN-SN38 was around 103 and 131nm, respectively. Polydispersity index (PDI) for all the formulations was around 0.2 and zeta potential was negative (-5 to -15mV). Nearly 90% of the drug was encapsulated in SLNs. SLN-SN38 and PEG-SLN-SN38 compared to irinotecan were significantly more toxic to C-26 and HT-116 cell lines after 48h of exposure. Calculation of IC50 suggests higher sensitivity of HT-116 cells than C-26 cells to SLN-SN38 and PEG-SLN-SN38. Tumor inhibitory efficacy presented the highest efficacy in SLN-SN38. However, both SLN-SN38 and PEG-SLN-SN38 carriers showed higher efficiency to inhibit tumors compared to irinotecan (25mg/kg).
Garg, Anuj; Bhalala, Kripal; Tomar, Devendra Singh; Wahajuddin
The present investigation aims to develop lumefantrine loaded binary solid lipid nanoparticles (LF-SLNs) to improve its poor and variable oral bioavailability. The oral bioavailability of LF is poor and variable due to its limited aqueous solubility and P-gp mediated efflux occurring in small intestine. LF-SLNs were prepared using binary lipid mixture of stearic acid and caprylic acid stabilized with TPGS (D-alpha tocopheryl polyethylene glycol 1000 succinate) and Poloxamer 188. Developed LF-SLNs were characterized for particle size distribution, zeta potential, entrapment efficiency, solid state properties and biopharmaceutical properties including in situ intestinal permeability and oral bioavailability. The particle size distribution, zeta potential and entrapment efficiency of optimized batch (LF-SLN7) was found to be 357.7±43.27nm, 25.29±1.15mV and 97.35±0.30%, respectively. DSC thermographs showed loss of crystalline nature of lumefantrine in LF-SLNs. In situ single pass intestinal permeability study (SPIP) study indicated significant enhancement in the effective intestinal permeability of LF from LF-SLN7 as compared to that of control. Pharmacokinetic study also showed significant increase in Cmax and area under curve (AUC0-∞) from LF-SLN7 (3860±521ng/mL and 43181±2557h×ng/mL, respectively) as compared to that of LF-control suspension (1425±563ng/mL and 19586±1537h×ng/mL, respectively). Thus, developed LF-SLNs can be promising to overcome P-gp efflux pump and enhance the oral bioavailability of lumefantrine.
Pardeike, Jana; Hommoss, Aiman; Müller, Rainer H
Solid lipid nanoparticles (SLN) are distinguishable from nanostructured lipid carriers (NLC) by the composition of the solid particle matrix. Both are an alternative carrier system to liposomes and emulsions. This review paper focuses on lipid nanoparticles for dermal application. Production of lipid nanoparticles and final products containing lipid nanoparticles is feasible by well-established production methods. SLN and NLC exhibit many features for dermal application of cosmetics and pharmaceutics, i.e. controlled release of actives, drug targeting, occlusion and associated with it penetration enhancement and increase of skin hydration. Due to the production of lipid nanoparticles from physiological and/or biodegradable lipids, this carrier system exhibits an excellent tolerability. The lipid nanoparticles are a "nanosafe" carrier. Furthermore, an overview of the cosmetic products currently on the market is given and the improvement of the benefit/risk ratio of the topical therapy is shown.
Ha, Yeonjeong; Katz, Lynn E; Liljestrand, Howard M
The distribution coefficient (Klipw) of fullerene between solid supported lipid membranes (SSLMs) and water was examined using different lipid membrane compositions. Klipw of fullerene was significantly higher with a cationic lipid membrane compared to that with a zwitterionic or anionic lipid membrane, potentially due to the strong interactions between negative fullerene dispersions and positive lipid head groups. The higher Klipw for fullerene distribution to ternary lipid mixture membranes was attributed to an increase in the interfacial surface area of the lipid membrane resulting from phase separation. These results imply that lipid composition can be a critical factor that affects bioconcentration of fullerene. Distribution of fullerene into zwitterionic unsaturated lipid membranes was dominated by the entropy contribution (ΔS) and the process was endothermic (ΔH > 0). This result contrasts the partitioning thermodynamics of highly and moderately hydrophobic chemicals indicating that the lipid-water distribution mechanism of fullerene may be different from that of molecular level chemicals. Potential mechanisms for the distribution of fullerene that may explain these differences include adsorption on the lipid membrane surfaces and partitioning into the center of lipid membranes (i.e., absorption).
Fan, Tingting; Chen, Chunhui; Guo, Han; Xu, Juan; Zhang, Jian; Zhu, Xi; Yang, Yang; Zhou, Zhou; Li, Lian; Huang, Yuan
Designing feasible and effective peptide ligand modified solid lipid nanoparticles (SLNs) to improve oral bioavailability of protein drugs and evaluating the influence of mucus remains important. In the present work, two kinds of peptide ligand modified SLNs loaded with salmon calcitonin (sCT), namely, sCT CSK-SLNs and sCT IRQ-SLNs, were prepared by coupling the peptide ligand CSKSSDYQC (CSK) which was reported to show affinity with goblet cells, or IRQRRRR (IRQ), a cell penetrating peptide, to polyoxyethylene (40) stearate (SA-PEG2000). Compared with unmodified SLNs, CSK or IRQ modified SLNs with better drug protection ability could facilitate the internalization of drug on Caco-2/HT29-MTX co-cultured cells and permeation in excised rat duodenum mucosa. The internalization mechanism of two kinds of peptide ligand modified SLNs was mainly active transport via both clathrin- and caveolae-dependent endocytosis. Although mucus was an impediment to the transport of SLNs, the peptide ligand modified SLNs still showed improved drug absorption. The absolute bioavailability of sCT CSK-SLNs (12.41 ± 3.65%) and sCT IRQ-SLNs (10.05 ± 5.10%) raised to 2.45-fold and 1.98-fold compared with unmodified SLNs (5.07 ± 0.54%), implying the feasibility and effectiveness of CSK and IRQ peptide modification for the enhancement of the oral bioavailability of protein drugs. In summary, the nanoparticles modified with CSK or IRQ peptide ligand could be the potential carriers for the transport of protein drugs across intestinal barriers.
Minelli, R; Occhipinti, S; Gigliotti, C L; Barrera, G; Gasco, P; Conti, L; Chiocchetti, A; Zara, G P; Fantozzi, R; Giovarelli, M; Dianzani, U; Dianzani, C
BACKGROUND AND PURPOSE Solid lipid nanoparticles containing cholesteryl butyrate (cholbut SLN) can be a delivery system for the anti-cancer drug butyrate. These nanoparticles inhibit adhesion of polymorphonuclear and tumour cells to endothelial cells and migration of tumour cells, suggesting that they may act as anti-inflammatory and anti-tumour agents. Here we have evaluated the effects of cholbut SLN on tumour cell growth using in vitro and in vivo models. EXPERIMENTAL APPROACH Cholbut SLNs were incubated with cultures of four tumour cell lines, and cell growth was analysed by assessing viability, clonogenic capacity and cell cycle. Effects on intracellular signalling was assessed by Western blot analysis of Akt expression. The in vivo anti-tumour activity was measured in two models of PC-3 cell xenografts in SCID/Beige mice. KEY RESULTS Cholbut SLN inhibited tumour cell line viability, clonogenic activity, Akt phosphorylation and cell cycle progression. In mice injected i.v. with PC3-Luc cells and treated with cholbut SLN, . in vivo optical imaging and histological analysis showed no metastases in the lungs of the treated mice. In another set of mice injected s.c. with PC-3 cells and treated with cholbut SLN when the tumour diameter reached 2 mm, analysis of the tumour dimensions showed that treatment with cholbut SLN substantially delayed tumour growth. CONCLUSION AND IMPLICATIONS Cholbut SLN were effective in inhibiting tumour growth in vitro and in vivo. These effects may involve, in part, inhibition of Akt phosphorylation, which adds another mechanism to the activity of this multipotent drug. PMID:23713413
Xie, Shuyu; Yang, Fei; Tao, Yanfei; Chen, Dongmei; Qu, Wei; Huang, Lingli; Liu, Zhenli; Pan, Yuanhu; Yuan, Zonghui
Enrofloxacin-loaded docosanoic acid solid lipid nanoparticles (SLNs) with different physicochemical properties were developed to enhance activity against intracellular Salmonella. Their cellular uptake, intracellular elimination and antibacterial activity were studied in RAW 264.7 cells. During the experimental period, SLN-encapsulated enrofloxacin accumulated in the cells approximately 27.06–37.71 times more efficiently than free drugs at the same extracellular concentration. After incubation for 0.5 h, the intracellular enrofloxacin was enhanced from 0.336 to 1.147 μg/mg of protein as the sizes of nanoparticles were increased from 150 to 605 nm, and from 0.960 to 1.147 μg/mg of protein when the charge was improved from −8.1 to −24.9 mv. The cellular uptake was more significantly influenced by the size than it was by the charge, and was not affected by whether the charge was positive or negative. The elimination of optimal SLN-encapsulated enrofloxacin from the cells was significantly slower than that of free enrofloxacin after removing extracellular drug. The inhibition effect against intracellular Salmonella CVCC541 of 0.24 and 0.06 μg/mL encapsulated enrofloxacin was stronger than 0.6 μg/mL free drug after all of the incubation periods and at 48 h, respectively. Docosanoic acid SLNs are thus considered as a promising carrier for intracellular bacterial treatment. PMID:28112240
Hwang, Tsong-Long; Aljuffali, Ibrahim A; Hung, Chi-Feng; Chen, Chun-Han; Fang, Jia-You
Cationic solid lipid nanoparticles (cSLNs) are extensively employed as the nanocarriers for drug/gene targeting to tumors and the brain. Investigation into the possible immune response of cSLNs is still lacking. The aim of this study was to evaluate the impact of cSLNs upon the activation of human polymorphonuclear neutrophil cells (PMNs). The cytotoxicity, pro-inflammatory mediators, Ca(2+) mobilization, mitogen-activated protein kinases (MAPKs), and neutrophil extracellular traps (NETs) as the indicators of PMN stimulation were examined in this work. The cSLNs presented a diameter of 195 nm with a zeta potential of 44 mV. The cSLNs could interact with the cell membrane to produce a direct membrane lysis and the subsequent cytotoxicity according to lactate dehydrogenase (LDH) elevation. The interaction of cSLNs with the membrane also triggered a Ca(2+) influx, followed by the induction of oxidative stress and degranulation. The cationic nanoparticles elevated the levels of superoxide anion and elastase by 24- and 9-fold, respectively. The PMN activation by cSLNs promoted the phosphorylation of p38 and Jun-N-terminal kinases (JNK) but not extracellular signal-regulated kinases (ERK). The imaging of scanning electron microscopy (SEM) and immunofluorescence demonstrated the production of NETs by cSLNs. This phenomenon was not significant for the neutral SLNs (nSLNs), although histones in NETs also increased after treatment of nSLNs. Our results suggest an important role of cSLNs in governing the activation of human neutrophils.
Ruiz de Garibay, A P; Solinís, M A; del Pozo-Rodríguez, A; Apaolaza, P S; Shen, J S; Rodríguez-Gascón, A
Here, we demonstrate the ability of solid lipid nanoparticle-based non-viral vectors to increase the α-galactosidase A levels of the IMFE1 cell line, an in vitro model for target cells in Fabry disease. For this purpose, vectors containing the pR-M10-αGal A plasmid, which encodes the α-galactosidase A enzyme, were prepared; the in vitro transfection efficacy was studied in IMFE1 cells, and the results were confirmed by RT-PCR. The cellular uptake of the vectors, intracellular disposition of the plasmid, and probable endocytosis pathways of the nanoparticles were also analyzed. The vectors used for the studies carried protamine (P-DNA-SLN), dextran and protamine (D-P-DNA-SLN), or hyaluronic acid of two different molecular weights and protamine (HA150-P-DNA-SLN or HA500-P-DNA-SLN). The new formulations, which presented a particle size in the range of nanometers (from 218 nm to 348 nm) and a positive superficial charge, were able to increase α-galactosidase A activity up to 4-fold in comparison to non treated IMFE1 cells. The most efficient vectors were those that included HA, and no differences due to changes in the molecular weight of HA were detected. The observed lack of colocalization with each of the four different Nile Red-labeled vectors and transferrin or cholera toxin appears to indicate that clathrin- and caveolae-independent pathways may be involved in their cellular uptake. Additionally, colocalization with LysoTracker indicated that the formulations were exposed to lysosomal activity, which may be responsible for the release of the plasmid from the vector. In conclusion, we reveal the potential of SLN-based vectors to efficiently transfect an immortalized Fabry patient cell line.
Amekyeh, Hilda; Billa, Nashiru; Yuen, Kah-Hay; Lim, Sheau Chin Sherlyn
Amphotericin B (AmB) is poorly absorbed from the gastrointestinal tract. Recent studies have suggested enhanced drug absorption from solid lipid nanoparticles (SLN). Little is known of the fate of AmB absorption within the gastrointestinal tract, and no gastrointestinal transit study has yet been performed on AmB-containing nano-formulations. We aimed to investigate the effect of food on the gastrointestinal transit properties of an AmB-containing SLN in rats. Three SLNs containing AmB, paracetamol, or sulfasalazine were formulated using cocoa butter and beeswax as lipid matrices and simultaneously administered orally to Sprague-Dawley rats. Paracetamol and sulfapyridine were used as marker drugs for estimating gastric emptying and cecal arrival, respectively. The pharmacokinetic data generated for paracetamol and sulfapyridine were used in estimating the absorption of the AmB SLNs in the small and large intestines, respectively. A delayed rate of AmB absorption was observed in the fed state; however, the extent of absorption was not affected by food. Specifically, the percentages of AmB absorption during the fasted state in the stomach, small intestine, and colon were not significantly different from absorption within the respective regions in the fed state. In both states, however, absorption was highest in the colon and appeared to be a combination of absorption from the small intestine plus absorption proper within the colon. The study suggests that AmB SLN, irrespective of food status, is slowly but predominantly taken up by the lymph, making the small intestine the most favorable site for the delivery of the AmB SLNs.
Gupta, Biki; Poudel, Bijay Kumar; Pathak, Shiva; Tak, Jin Wook; Lee, Hee Hyun; Jeong, Jee-Heon; Choi, Han-Gon; Yong, Chul Soon; Kim, Jong Oh
Imatinib (IMT), an anticancer agent, inhibits receptor tyrosine kinases and is characterized by poor aqueous solubility, extensive first-pass metabolism, and rapid clearance. The aims of the current study are to prepare imatinib-loaded solid lipid nanoparticles (IMT-SLN) and study the effects of associated formulation variables on particle size and drug encapsulation on IMT-SLN using an experimental design. IMT-SLN was optimized by use of a "combo" approach involving Plackett-Burman design (PBD) and Box-Behnken design (BBD). PBD screening resulted in the determination of organic-to-aqueous phase ratio (O/A), drug-to-lipid ratio (D/L), and amount of Tween® 20 (Tw20) as three significant variables for particle size (S z), drug loading (DL), and encapsulation efficiency (EE) of IMT-SLN, which were used for optimization by BBD, yielding an optimized criteria of O/A = 0.04, D/L = 0.03, and Tw20 = 2.50% w/v. The optimized IMT-SLN exhibited monodispersed particles with a size range of 69.0 ± 0.9 nm, ζ-potential of -24.2 ± 1.2 mV, and DL and EE of 2.9 ± 0.1 and 97.6 ± 0.1% w/w, respectively. Results of in vitro release study showed a sustained release pattern, presumably by diffusion and erosion, with a higher release rate at pH 5.0, compared to pH 7.4. In conclusion, use of the combo experimental design approach enabled clear understanding of the effects of various formulation variables on IMT-SLN and aided in the preparation of a system which exhibited desirable physicochemical and release characteristics.
Al-Amin, Md; Cao, Jiafu; Naeem, Muhammad; Banna, Hasanul; Kim, Min-Soo; Jung, Yunjin; Chung, Hae Young; Moon, Hyung Ryong; Yoo, Jin-Wook
Hyperpigmentation caused by melanin overproduction is a major skin disorder in humans. Inhibition of tyrosinase, a key regulator of melanin production, has been used as an effective strategy to treat hyperpigmentation. In this study, we investigated the use of solid lipid nanoparticles (SLNs) as a highly effective and nontoxic means to deliver a newly synthesized potent tyrosinase inhibitor, MHY498, and to target melanocytes through the skin. MHY498-loaded SLNs (MHY-SLNs) were prepared by an oil-in-water emulsion solvent-evaporation method, and their morphological and physicochemical properties were characterized. MHY-SLNs showed a prolonged drug-release profile and higher skin permeation than that of MHY solution. In an in vivo evaluation of antimelanogenic activity, MHY-SLNs showed a prominent inhibitory effect against ultraviolet B-induced melanogenesis, resulting in no change in the skin color of C57BL/6 mouse, compared with that observed in an MHY solution-treated group and an untreated control group. The antimelanogenic effect of MHY-SLNs was further confirmed through Fontana-Masson staining. Importantly, MHY-SLNs did not induce any toxic effects in the L929 cell line. Overall, these data indicate that MHY-SLNs show promise in the topical treatment of hyperpigmentation.
Kim, Sanghoon; Diab, Roudayna; Joubert, Olivier; Canilho, Nadia; Pasc, Andreea
Newly designed microcapsules (MC) combining a core of solid lipid nanoparticle (SLN) and a mesoporous silica shell have been developed and explored as oral delivery system of curcumin (CU). CU-loaded MC (MC-CU) are 2 μm sized and have a mesoporous silica shell of 0.3 μm thickness with a wormlike structure as characterized by small angle X-ray scattering (SAXS), nitrogen adsorption/desorption and transmission electron microscopy (TEM) measurements. It was found that SLN acts as reservoir of curcumin while the mesoporous shell insures the protection and the controlled release of the drug. MC-CU displayed a pH-dependent in vitro release profile with marked drug retention at pH 2.8. Neutral red uptake assay together with confocal laser scanning microscopy (CLSM) showed a good cell tolerance to MC-CU at relatively high concentration of inert materials. Besides, the cell-uptake test revealed that fluorescent-MC were well internalized into Caco-2 cells, confirming the possibility to use MC for gut cells targeting. These findings suggest that organic core-silica shell microcapsules are promising drug delivery systems with enhanced bioavailability for poorly soluble drugs.
Dal Magro, R; Ornaghi, F; Cambianica, I; Beretta, S; Re, F; Musicanti, C; Rigolio, R; Donzelli, E; Canta, A; Ballarini, E; Cavaletti, G; Gasco, P; Sancini, G
Solid lipid nanoparticles (SLN) are colloidal drug delivery systems characterized by higher entrapment efficiency, good scalability of the preparation process and increased sustained prolonged release of the payload compared to other nanocarriers. The possibility to functionalize the surface of SLN with ligands to achieve a site specific targeting makes them attractive to overcome the limited blood-brain barrier (BBB) penetration of therapeutic compounds. SLN are prepared for brain targeting by exploiting the adaptability of warm microemulsion process for the covalent surface modification with an Apolipoprotein E-derived peptide (SLN-mApoE). Furthermore, the influence of the administration route on SLN-mApoE brain bioavailability is here evaluated. SLN-mApoE are able to cross intact a BBB in vitro model. The pulmonary administration of SLN-mApoE is related to a higher confinement in the brain of Balb/c mice compared to the intravenous and intraperitoneal administration routes, without inducing any acute inflammatory reaction in the lungs. These results promote the pulmonary administration of brain-targeted SLN as a feasible strategy for improving brain delivery of therapeutics.
Martins, Susana; Tho, Ingunn; Reimold, Isolde; Fricker, Gert; Souto, Eliana; Ferreira, Domingos; Brandl, Martin
For the purpose of brain delivery upon intravenous injection, formulations of camptothecin-loaded solid lipid nanoparticles (SLN), prepared by hot high pressure homogenisation, were designed. Incorporation of camptothecin in the hydrophobic and acidic environment of SLN matrix was chosen to stabilise the lactone ring, which is essential for its antitumour activity, and for avoiding premature loss of drug on the way to target camptothecin to the brain. A multivariate approach was used to assess the influence of the qualitative and quantitative composition on the physicochemical properties of camptothecin-loaded SLN in comparison to plain SLN. Mean particle sizes of ≤200 nm, homogenous size distributions and high encapsulation efficiencies (>90%) were achieved for the most suitable formulations. In vitro release studies in plasma, showed a prolonged release profile of camptothecin from SLN, confirming the physical stability of the particles under physiological pH. A higher affinity of the SLN to the porcine brain capillary endothelial cells (BCEC) was shown in comparison to macrophages. MTT studies in BCEC revealed a moderate decrease in the cell viability of camptothecin, when incorporated in SLN compared to free camptothecin in solution. In vivo studies in rats showed that fluorescently labelled SLN were detected in the brain after i.v. administration. This study indicates that the camptothecin-loaded SLN are a promising drug brain delivery system worth to explore further for brain tumour therapy.
Al-Amin, Md; Cao, Jiafu; Naeem, Muhammad; Banna, Hasanul; Kim, Min-Soo; Jung, Yunjin; Chung, Hae Young; Moon, Hyung Ryong; Yoo, Jin-Wook
Hyperpigmentation caused by melanin overproduction is a major skin disorder in humans. Inhibition of tyrosinase, a key regulator of melanin production, has been used as an effective strategy to treat hyperpigmentation. In this study, we investigated the use of solid lipid nanoparticles (SLNs) as a highly effective and nontoxic means to deliver a newly synthesized potent tyrosinase inhibitor, MHY498, and to target melanocytes through the skin. MHY498-loaded SLNs (MHY-SLNs) were prepared by an oil-in-water emulsion solvent-evaporation method, and their morphological and physicochemical properties were characterized. MHY-SLNs showed a prolonged drug-release profile and higher skin permeation than that of MHY solution. In an in vivo evaluation of antimelanogenic activity, MHY-SLNs showed a prominent inhibitory effect against ultraviolet B-induced melanogenesis, resulting in no change in the skin color of C57BL/6 mouse, compared with that observed in an MHY solution-treated group and an untreated control group. The antimelanogenic effect of MHY-SLNs was further confirmed through Fontana–Masson staining. Importantly, MHY-SLNs did not induce any toxic effects in the L929 cell line. Overall, these data indicate that MHY-SLNs show promise in the topical treatment of hyperpigmentation. PMID:27980392
Jain, Aviral; Singhai, Priyanka; Gurnany, Ekta; Updhayay, Satish; Mody, Nishi
Blood-brain barrier restricts the uptake of many important hydrophilic drugs and limits their efficacy in the treatment of brain diseases because of the presence of tight junctions, high metabolic capacity, low pinocytic vesicular traffic, and efficient efflux mechanisms. In the present project, transferrin (Tf)-conjugated solid lipid nanoparticles (Tf-SLNs) were investigated for their ability to deliver temozolomide (TMZ) to the brain. SLNs were prepared by an ethanol injection method using hydrogenated soya phosphatidylcholine, triolein, cholesterol and distearoylphosphatidylethanolamine. Conjugation of SLNs with Tf was achieved by incubation of Tf with TMZ-loaded SLNs in the presence of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride in phosphate buffered saline (pH 7.4) as a cross linker. SLNs preparation were characterized for particle size, polydispersity index, zeta potential, surface morphology, percent drug entrapment efficiency, in vitro drug release, and hemolytic toxicity studies. In vitro cytotoxicity studies were performed on human cancer cell lines. The average size was found to be 221 ± 3.22 nm with entrapment efficiency of 69.83 ± 2.52 and 249 ± 2.61 nm with entrapment efficiency decreased to 64.21 ± 2.27 % for unconjugated SLNs and Tf-SLNs, respectively. Fluorescence studies revealed the enhanced uptake of Tf-SLNs in brain tissue compared with unconjugated SLNs.
Moazeni, Maryam; Kelidari, Hamid Reza; Saeedi, Majid; Morteza-Semnani, Ketayoun; Nabili, Mojtaba; Gohar, Atefeh Abdollahi; Akbari, Jafar; Lotfali, Ensieh; Nokhodchi, Ali
Antifungal therapy results in complications in management due to changes in the patterns of epidemiology and drug susceptibility of invasive fungal infections. In this study, we prepared fluconazole-loaded solid lipid nanoparticles (FLZ-SLNs) and investigated the efficacy of the optimal formulation on fluconazole (FLZ)-resistant strains of several Candida species. FLZ-SLN was produced using probe ultrasonication techniques. The morphology of the obtained SLNs was characterized by field emission scanning electron microscopy. The minimum inhibitory concentrations for the new formulations against fluconazole-resistant strains of Candida were investigated using CLSI document M27-A3. The FLZ-SLNs presented a spherical shape with a mean diameter, zeta potential and entrapment efficiency of 84.8nm, -25mV and 89.6%, respectively. The drug release from FLZ-SLNs exhibited burst release behaviour at the initial stage (the first 30min) followed by a sustained release over 24h FLZ-resistant yeast strains behaved as susceptible strains after treatment with FLZ-SLNs (≤8μg/ml). The MIC50 drug concentrations were 2μg/ml, 1μg/ml and 2μg/ml for FLZ-resistant strains of Candida albicans, Candida parapsilosis and Candida glabrata, respectively. In this study, we evaluated novel delivery systems for combating Candida strains that exhibit low susceptibility against the conventional formulation of FLZ as a first-line treatment.
Saljoughian, N; Zahedifard, F; Doroud, D; Doustdari, F; Vasei, M; Papadopoulou, B; Rafati, S
The use of an appropriate delivery system has recently emerged as a promising approach for the development of effective vaccination against visceral leishmaniasis (VL). Here, we compare two vaccine delivery systems, namely electroporation and cationic solid-lipid nanoparticle (cSLN) formulation, to administer a DNA vaccine harbouring the L. donovani A2 antigen along with L. infantum cysteine proteinases [CPA and CPB without its unusual C-terminal extension (CPB(-CTE) )] and evaluate their potential against L. infantum challenge. Prime-boost administration of the pcDNA-A2-CPA-CPB(-CTE) delivered by either electroporation or cSLN formulation protects BALB/c mice against L. infantum challenge and that protective immunity is associated with high levels of IFN-γ and lower levels of IL-10 production, leading to a strong Th1 immune response. At all time points, the ratio of IFN-γ: IL-10 induced upon restimulation with rA2-rCPA-rCPB and F/T antigens was significantly higher in vaccinated animals. Moreover, Th2-efficient protection was elicited through a high humoral immune response. Nitric oxide production, parasite burden and histopathological analysis were also in concordance with other findings. Overall, these data indicate that similar to the electroporation delivery system, cSLNs as a nanoscale vehicle of Leishmania antigens could improve immune response, hence indicating the promise of these strategies against visceral leishmaniasis.
Baek, Jong-Suep; Cho, Cheong-Weon
Paclitaxel (PTX) has been used in the treatment of wide range of cancers but its entry into cancer cell is restricted by p-glycoprotein (p-gp). Also, it was reported that verapamil (VP) could inhibit p-gp efflux. Hence, three kinds of solid lipid nanoparticles (SLN) such as PVS (PTX and VP co-loaded SLN), PSV (PTX loaded SLN, later added VP) and PVSV (PTX and VP co-loaded SLN, later added VP) were prepared to overcome MDR by combination of PTX and VP. PVS was the SLN loaded with both PTX and VP at the same time. PSV was the SLN loaded with PTX and then modified with VP - complexed hydroxypropyl-β-cylcodextrin (HPCD). Finally, PVSV was the SLN loaded with PTX and half of VP at the same time subsequently, modified with half of VP - complexed HPCD. The physicochemical characterizations of PVS, PSV or PVSV such as particle size, zeta potential, encapsulation efficiency or in vitro PTX release were examined. PVSV showed that release of VP was higher than PTX solution in first 15h and sustained release of both VP and PTX. PVSV showed significantly higher cytotoxicity and cellular uptake than that of the PTX solution in MCF-7/ADR resistant cells. Furthermore, PVSV significantly down regulated the expression of p-gp than the PTX solution in MCF-7/ADR resistant cells. Based on these findings, this study indicated that the PVSV exhibited great potential for breast cancer therapy.
Trapani, Adriana; Mandracchia, Delia; Di Franco, Cinzia; Cordero, Héctor; Morcillo, Patricia; Comparelli, Roberto; Cuesta, Alberto; Esteban, Maria Angeles
The primary aim of the present work was to evaluate the in vitro uptake of 6-Coumarin (6COUM) loaded solid lipid nanoparticles (SLN) by two gilthead seabream (Sparus aurata L.) cell types: an established cell line (SAF-1 cells) and the primary cultures of head-kidney (HK)-the main haemopoietic organ in fish, equivalent to mammalian bone marrow-leucocytes. For this purpose, after the physicochemical characterization of SLN, the uptake by those immunocompetent fish cells was evaluated using flow cytometry and confocal microscopy. Concomitantly, the uptake of 6-COUM loaded SLN was compared with that achieved with 6-COUM loaded pectin microparticles (MPs), which were selected as a competitor of the delivery carriers. After SLN and MP physicochemical characterization, the results demonstrated that SAF-1 cells were able to internalize high percentages of 6-COUM SLNs when incubated for 4, 8 and 24h, with the highest SLN concentration tested (10 μg/ml). The ability of HK leucocytes to internalize SLN was also found to vary depending on both incubation time and SLN concentration. The highest values of HK leucocytes internalizing SLN particles (around 16%) were detected at the maximum SLN concentration (20 μg/ml) at incubation times of 4 or 8h. Conversely, HK leucocytes were unable to internalize MPs at any tested concentration and incubation time. A possible mechanism explaining the uptake into cells is proposed. The present work constitutes the first approximation to consider SLN as nanocarriers for delivering biologically active substances to fish.
Pyo, Sung Min; Meinke, Martina; Klein, Anja F; Fischer, Tanja C; Müller, Rainer H
For the post laser treatment of couperosis a new dermal formulation was developed combining three actives: vitamin K1, A1 and rutin, where both vitamins were incorporated into solid lipid nanoparticles (SLN) and the poorly soluble antioxidant rutin formulated as nanocrystal. All three formulations were stable over 6 months either on their own or after their incorporation into a hydrogel. Vitamin A1 at 0.3% in emulsions shows local skin irritation due to very rapid release. By forming SLN, prolonged release with less irritation potential but deeper penetration was achieved in porcine ear skin. Due to the nanosized rutin, the new hydrogel showed clearly increased antioxidant activity, representing a stronger protection potential against reactive oxygen species (ROS), compared to marketed anti-redness products with rutin as raw drug powder or water-soluble derivative. In addition, rutin nanocrystals showed up to 5 times pronounced penetration compared to μm-sized raw drug powder. The orientating in-vivo case study revealed a three to six times faster recovery after laser treatment of couperosis by twice daily application of the new hydrogel, regarding scabbed-over areas and erythema. Continued use of the new gel also showed preventive properties against recurrences of veins for at least 8 month.
Zhang, Dianrui; Tan, Tianwei; Gao, Lei
Oridonin, a lipophilic Chinese medicine, has very low oral bioavailability due to its poor solubility. Solid lipid nanoparticle (SLN) delivery systems of oridonin have been formed using stearic acid, soybean lecithin and pluronic F68 in our studies to overcome this problem. Emulsion evaporation-solidification at low temperature was used to prepare SLN dispersions. The particle size and morphology were examined by transmission electron microscopy (TEM), and the zeta potential was measured by a television micro-electrophoresis apparatus. Process and formulation variables have been studied and optimized on the basis of entrapment efficiency. Differential scanning calorimetry (DSC) and powder x-ray diffraction (PXRD) studies were performed to characterize the state of the drug. In vitro release studies were performed in phosphate-buffer solution (PBS) (pH 7.4). The tissue distribution in mice and the pharmacokinetics in rabbits were studied to evaluate the tissue targeted property of SLNs. Stable SLN formulations of oridonin having a mean size range of 15-35 nm and mean zeta potential -45.07 mV were developed. More than 40% oridonin was entrapped in SLNs. DSC and PXRD analysis showed that oridonin is dispersed in SLNs in an amorphous state. The release pattern of the drug was analysed and found to follow the Higuchi equations. In vivo studies demonstrated that oridonin-loaded SLNs obviously increased the concentration of oridonin in liver, lung and spleen, while its distribution in heart and kidney decreased.
Liu, Wei; Hu, Meiling; Liu, Wenshuang; Xue, Chengbin; Xu, Huibi; Yang, XiangLiang
The purpose of this study was to investigate solid lipid nanoparticles (SLN) hydrogel for transdermal iontophoretic drug delivery. Triamcinolone acetonide acetate (TAA), a glucocorticoids compound, was employed as the model drug. SLN containing the drug triamcinolone acetonide acetate (TAA-SLN) and their carbopol gel with stable physicochemical properties were prepared. The use of TAA-SLN carbopol gel as a vehicle for the transdermal iontophoretic delivery of TAA was evaluated in vitro using horizontal diffusion cells fitted with porcine ear skin. We found that the TAA-SLN gel possessed good stability, rheological properties, and high electric conductance. Transdermal penetration of TAA from TAA-SLN gel cross the skin tissue was significantly enhanced by iontophoresis. The enhancement of the cumulative penetration amount and the steady-state penetration flux of the penetrated drug were related to the particle size of TAA-SLN and the characteristics of the applied pulse electric current, such as density, frequency, and on/off interval ratio. These results indicated that SLN carbopol gel could be used as a vehicle for transdermal iontophoretic drug delivery under suitable electric conditions.
Li, Jian-Chun; Zhang, Wen-Jing; Zhu, Jin-Xiu; Zhu, Na; Zhang, Hong-Min; Wang, Xiu; Zhang, Jin; Wang, Qing-Qing
To investigate the brain delivery in rat by nasal Quetiapine fumarate (QF) loaded with solid lipid nanoparticles in situ gel (QF-SLN-gel). QF-SLN-gel was prepared through micro-emulsion technique. The rat model of schizophrenia was established by intraperitoneal injection of (+)-MK-801, evaluated by stereotypic behavior, Mori’s Water Maze (MWM) test and hematoxylin and eosin (HE) staining of hippocampus. The animals were administrated with QF via oral, nasal or tail vein approach and the concentration of QF in blood and brain was determined using high performance liquid chromatography (HPLC). The QF-SLN-gel was even and transparent, having size of 117.8±2.67 d.nm, potential of 57.2±0.24 mV and EF of 97.6±0.58%. After administration of QF-SLN-gel, the concentration of QF in blood and brain of rats in nasal QF-SLN-gel group was similar with that of rats in tail vein QF group, but significantly higher than that of rats in oral QF group. The hippocampal morphology changes induced by (+)-MK-801 were ameliorated by QF, with advantage of nasal QF-SLN-gel over tail vein QF. The nasal QF-SLN-gel had stable and good brain delivery and could ameliorate the damages in rat model of schizophrenia induced by (+)-MK-801. PMID:26770349
Pooja, Deep; Tunki, Lakshmi; Kulhari, Hitesh; Reddy, Bharathi B; Sistla, Ramakrishna
This data article contains the data related to the research article "Characterization, biorecognitive activity and stability of WGA grafted lipid nanostructures for the controlled delivery of rifampicin" (Pooja et al. 2015) . In the present study, SLN were prepared by a single emulsification-solvent evaporation method and the various steps of SLN preparation are shown in a flow chart. The preparation of SLN was optimized for various formulation variables including type and quantity of lipid, surfactant, amount of co-surfactant and volume of organic phase. Similarly, effect of variables related to homogezation, sonication and stirring processes, on the size and surface potential of SLN was determined and optimized.
Bhushan, Shashi; Kakkar, Vandita; Pal, Harish Chandra; Mondhe, D M; Kaur, Indu Pal
AP9-cd, a novel lignan composition from Cedrus deodara has significant anticancer potential, and to further enhance its activity, it was lucratively encumbered into solid lipid nanoparticles (SLNs). These nanoparticles were formulated by micro-emulsion technique with 70% drug trap competence. AP9-cd-SLNs were regular, solid, globular particles in the range of 100-200 nm, which were confirmed by electron microscopic studies. Moreover, AP9-cd-SLNs were found to be stable for up to six months in terms of color, particle size, zeta potential, drug content and entrapment. AP9-cd-SLNs have 30-50% higher cytotoxic and apoptotic potential than the AP9-cd alone. The augmented anticancer potential of AP9-cd-SLNs was observed in cytotoxic IC50 value, apoptosis signaling cascade and in Ehrlich ascites tumor (EAT) model. AP9-cd-SLNs induce apoptosis in Molt-4 cells via both intrinsic and extrinsic pathway. Moreover, the dummy nanoparticles (SLNs without AP9-cd) did not have any cytotoxic effect in cancer as well as in normal cells. Consequently, SLNs of AP9-cd significantly augment the apoptotic and antitumor potential of AP9-cd. The present study provides a podium for ornamental the remedial latent via novel delivery systems like solid lipid nanoparticles.
Shah, Kumar A; Joshi, Medha D; Patravale, Vandana B
The objective of the present investigation was to fabricate glyceryl monostearate SLN by employing a biocompatible microemulsion as a template. Biocompatible excipients such as Tween 20 (as a surfactant) and Transcutol P (a cosourfactant) (at different K(m) ratios) were selected for the fabrication of microemulsions. Pseudo-ternary phase diagrams were plotted to identify the area of the microemulsion existence. Glyceryl monostearate SLN were fabricated by dispersing the microemulsion (maintained at 65 degrees C) into cold water (maintained at 2-3 degrees C). The particle size of the SLN was determined by photon correlation spectroscopy. Tretinoin, a lipophilic anti-acne agent was incorporated into SLN as a model drug. The encapsulation efficiency of tretinoin in the SLN was determined by using Nanosep ultrafilteration device at different lipid loads viz. 1%, 1.5% and 2%. Glyceryl monostearate SLN fabricated from biocompatible microemulsion template exhibited average particle size of 175 nm and polydispersity index of 0.833. Tretinoin could be successfully incorporated into SLN and the encapsulation efficiency ranged from 37-48% at different lipid loads.
Kunasekaran, Viveksarathi; Krishnamoorthy, Kannan
The objective of this study was to select best method for the development of rasagiline mesylate (RM) loaded nanoscale solid lipid particles using analytic hierarchy process (AHP). Improper method selection may lead to waste of time, loss of material and financial resources. One of the possibilities to overcome these difficulties, AHP was employed to find the suitable method. In the AHP, a decision of hierarchy was constructed with a goal, criteria, sub-criteria, and alternatives. After constructing the AHP, the expert choice software was used to compute the overall priority of criteria, sub-criteria and alternatives. The best alternative selected was based on the highest priority. Nanoscale solid lipid particles of RM was formulated by the selected microemulsion method (M4) and it shows the particle size, polydispersity index and zeta potential were within acceptable limits. Drug content and entrapment efficiency of the RM-solid lipid nanoparticles were 97.26% and 86.57%, respectively. This study concludes that the AHP was viable and effective tool for selecting a most suitable method for the fabrication of RM loaded nanoscale solid lipid particles.
Yasir, Mohd; Sara, Udai Vir Singh
In the present study, haloperidol (HP)-loaded solid lipid nanoparticles (SLNs) were prepared to enhance the uptake of HP to brain via intranasal (i.n.) delivery. SLNs were prepared by a modified emulsification-diffusion technique and evaluated for particle size, zeta potential, drug entrapment efficiency, in vitro drug release, and stability. All parameters were found to be in an acceptable range. In vitro drug release was found to be 94.16±4.78% after 24 h and was fitted to the Higuchi model with a very high correlation coefficient (R (2)=0.9941). Pharmacokinetics studies were performed on albino Wistar rats and the concentration of HP in brain and blood was measured by high performance liquid chromatography. The brain/blood ratio at 0.5 h for HP-SLNs i.n., HP sol. i.n. and HP sol. i.v. was 1.61, 0.17 and 0.031, respectively, indicating direct nose-to-brain transport, bypassing the blood-brain barrier. The maximum concentration (C max) in brain achieved from i.n. administration of HP-SLNs (329.17±20.89 ng/mL, T max 2 h) was significantly higher than that achieved after i.v. (76.95±7.62 ng/mL, T max 1 h), and i.n. (90.13±6.28 ng/mL, T max 2 h) administration of HP sol. The highest drug-targeting efficiency (2362.43%) and direct transport percentage (95.77%) was found with HP-SLNs as compared to the other formulations. Higher DTE (%) and DTP (%) suggest that HP-SLNs have better brain targeting efficiency as compared to other formulations.
Wang, Taoran; Hu, Qiaobin; Zhou, Mingyong; Xia, Yan; Nieh, Mu-Ping; Luo, Yangchao
Solid lipid nanoparticles (SLNs) have gained tremendous attraction as carriers for controlled drug delivery. Despite numerous advances in the field, one long-standing historical challenge for their practical applications remains unmet: redispersibility after drying. In this work, a novel design of SLNs using a layer-by-layer (LbL) technique was developed and the formulations were optimized by surface response methodology (Box-Behnken design). To the best of our knowledge, this is the first study reporting the fabrication of SLNs from all natural ingredients in the absence of any synthetic surfactants or coatings. The SLNs were prepared by a combined solvent-diffusion and hot homogenization method, with soy lecithin as natural emulsifier (first layer), followed by the subsequent coating with sodium caseinate (second layer) and pectin (third layer), both of which are natural food biopolymers. The adsorption of pectin coating onto caseinate was reinforced by hydrophobic and electrostatic interactions induced by a pH-driven process along with thermal treatment. The innovative nano spray drying technology was further explored to obtain ultra-fine powders of SLNs. Compared to uncoated or single-layer coated SLNs powders, which showed severe aggregation after spray drying, the well-separated particles with spherical shape and smooth surface were obtained for layer-by-layer (LbL) SLNs, which were redispersible into water without variation of dimension, shape and morphology. The SLNs were characterized by Fourier transform infrared and high-performance differential scanning calorimetry for their physical properties. The LbL-coated SLNs based on all natural ingredients have promising features for future applications as drug delivery systems, overcoming the major obstacles in conventional spray drying and redispersing SLNs-based formulations.
Yasir, Mohd; Sara, Udai Vir Singh
In the present study, haloperidol (HP)-loaded solid lipid nanoparticles (SLNs) were prepared to enhance the uptake of HP to brain via intranasal (i.n.) delivery. SLNs were prepared by a modified emulsification–diffusion technique and evaluated for particle size, zeta potential, drug entrapment efficiency, in vitro drug release, and stability. All parameters were found to be in an acceptable range. In vitro drug release was found to be 94.16±4.78% after 24 h and was fitted to the Higuchi model with a very high correlation coefficient (R2=0.9941). Pharmacokinetics studies were performed on albino Wistar rats and the concentration of HP in brain and blood was measured by high performance liquid chromatography. The brain/blood ratio at 0.5 h for HP-SLNs i.n., HP sol. i.n. and HP sol. i.v. was 1.61, 0.17 and 0.031, respectively, indicating direct nose-to-brain transport, bypassing the blood–brain barrier. The maximum concentration (Cmax) in brain achieved from i.n. administration of HP-SLNs (329.17±20.89 ng/mL, Tmax 2 h) was significantly higher than that achieved after i.v. (76.95±7.62 ng/mL, Tmax 1 h), and i.n. (90.13±6.28 ng/mL, Tmax 2 h) administration of HP sol. The highest drug-targeting efficiency (2362.43%) and direct transport percentage (95.77%) was found with HP-SLNs as compared to the other formulations. Higher DTE (%) and DTP (%) suggest that HP-SLNs have better brain targeting efficiency as compared to other formulations. PMID:26579417
Shrotriya, S N; Ranpise, N S; Vidhate, B V
Irritant contact dermatitis (ICD) is a chronic and relapsing skin disease with severe eczematous lesions. Despite its growing prevalence, therapeutic treatments remain limited. Long-term topical corticosteroid treatment can induce skin atrophy, hypopigmentation, and increase in transepidermal water loss. An innovative dermal treatment is essential to reduce the side effects of corticosteroids. Topical resveratrol (RES), although effective for ICD, is a challenging molecule due to low solubility and poor bioavailability. The objective of this work was to build RES-loaded solid lipid nanoparticles (RES-SLNs) with skin targeting. For this purpose, RES-SLNs were prepared using the probe ultrasonication method utilizing Precirol ATO 5 and Tween 20. The RES-SLNs were evaluated for particle size, entrapment efficiency (EE), and transmission electron microscopy (TEM) studies. Further, RES-SLNs were incorporated into Carbopol gel and investigated for ex vivo skin permeation, deposition study on human cadaver skin, and finally skin irritation study on New Zealand White rabbits. It was further assessed for possible beneficial effects on ICD using BALB/c mice. RES-SLN showed mean size below 100 nm and 68-89% EE. TEM studies confirmed spherical particles in the nanometer range. An ex vivo study of RES-SLN-loaded gel exhibited controlled drug release up to 24 h; similarly, in vitro drug deposition studies showed potential of skin targeting with no skin irritation. RES-SLN gel confirmed competent suppression of ear swelling and reduction in skin water content in the BALB/c mouse model of ICD when compared to marketed gel. Thus, the formulated RES-SLN gel would be a safe and effective alternative to conventional vehicles for treatment of ICD.
Sampaio, A C; Mendes, R J; Castro, P G; Silva, A M
Solid lipid nanoparticles (SLNs) are used as carriers for drug delivery, and are high biocompatible and designed to endure in the host organism. Despite its current industrial production is low, many of these substances are available on the market, and much more are in the production pipeline. As a result, many of them will end in aquatic systems raising the question whether they can pose a risk to aquatic biota and the associated ecological processes. Microbial decomposers of plant litter, play a key role in forested streams being responsible for the energy flow between terrestrial and aquatic environments. Here, we investigated the effects of SLNs on alder leaf litter decomposition by aquatic microbes. Alder leaves were immersed in a stream of Northeast Portugal to allow microbial colonization before being exposed in microcosms of two types of SLNs at two concentrations for 42 days. Results showed that rates of leaf decomposition decreased with exposure to SLNs. Bacterial biomass was not inhibited by SLNs, and cultivable fungi densities remained constant (SLN-A) or increased (SLN-C) compared with control microcosms. The type and concentration of SLNs influenced differently the leaf colonization by fungi as well as fungal sporulation rate. These effects were accompanied by changes in the community extraenzymatic profile: the activities of alkaline phosphatase, acidic phosphatase, Naphthol-AS-BI-phosphohydrolase (P cycle) and lipases increased in the SLNs microcosms. This study provided the first evidence of the adverse effects of the release of SLNs to streams on leaf litter decomposition. Those effects seem to depend on the composition and concentration of SLNs, as well on the microbial target group, or enzyme. Thus, prior to massive industrial production of these nanomaterials, some measures should be taken to avoid environmental impact affecting the microbial communities responsible for detritus decomposition.
Zhang, Xiaoyun; Qiao, Hua; Chen, Ying; Li, Lin; Xia, Huxiong; Shi, Yanbin
Low molecular weight heparin-modified isoliquiritigenin-loaded solid lipid nanoparticle (LMWH-ISL-SLN) was developed for injective application. The morphological observation, particle diameter and zeta potential of LMWH-ISL-SLN were characterized using transmission electron microscopy (TEM) and a Malvern Zetasizer. Its entrapment efficiency (EE) and drug loading (DL) were determined by ultracentrifuge. The in-vitro release experiments were performed by dialysis technique. The cytotoxic effects of LMWH-ISL-SLN on Hep-G2 cell lines were determined using an MTT assay. Pharmacokinetic and tissue distribution studies were conducted in kunming mice after intravenous administration of LMWH-ISL-SLN. The average drug entrapment efficiency for LMWH-ISL-SLN was (99.80 ± 3.27)%, drug loading was (18.68 ± 1.51)%, mean particle size was (217.53 ± 4.86) nm and zeta potential was (–18.24 ± 2.47) mV. The in-vitro release experiments demonstrated isoliquiritigenin release from LMWH-ISL-SLN was in line with Weibull’s distribution law. Hemolysis test and dose-related toxic effects proved that LMWH-ISL-SLN was a safe and non toxic product when given by intravenous injection. The pharmacokinetics results of LMWH-ISL-SLN showed that the area under the concentration-time curve (AUC0→∞)of LMWH-ISL-SLN was greater than that for the isoliquiritigenin solution in plasma. Tissue distribution study indicated that ISL were mainly distributed in the liver and lung. In conclusion, low molecular weight heparin-modified SLN system is a promising carrier for the intravenous delivery of ISL. PMID:27980562
Ramalingam, Prakash; Ko, Young Tag
Despite the therapeutic effects of resveratrol, its clinical application is restricted by its poor oral bioavailability, low water solubility, and instability. Solid lipid nanoparticles (SLNs)-based drug delivery systems have been shown to provide excellent support for the delivery of hydrophobic drugs. The poor stability and burst release behavior in stomach acidic pH conditions of SLNs result in increased aggregation of the particles in the gastrointestinal environment, limiting the success of these particles as an oral delivery system for hydrophobic drugs. N-trimethyl chitosan (TMC) graft palmitic acid (PA) (TMC-g-PA) mucoadhesive copolymer was hypothesized to be a promising candidate for the surface modification of PA-decorated resveratrol-loaded SLNs to stabilize SLNs and circumvent all the above mentioned obstacles. TMC and TMC-g-PA copolymers were therefore synthesized and characterized by (1)H-nuclear magnetic resonance ((1)H NMR) and Fourier-transformed infra-red (FT-IR) spectroscopy. Resveratrol-loaded SLNs (SLRNs) that comprised Precirol ATO 5, PA, Gelucire 50/13, Tween 80, and resveratrol as well as TMC-g-PA SLRNs were formulated and characterized in terms of physicochemical properties, stability, cytotoxicity, and in vitro and in vivo effects. The in vitro release studies of TMC-g-PA SLRNs demonstrated negligible release of resveratrol in simulated gastric and sustained release in simulated intestinal conditions and the relative bioavailability of resveratrol was furthermore found to be 3.8-fold higher from TMC-g-PA SLRNs than that from resveratrol suspension. Overall, the findings reported here indicate that TMC-g-PA SLRNs represent a potential oral drug delivery system for resveratrol.
da Silva, Camila Morais Gonçalves; Pasquoto, Tatiane; de Lima, Renata; Fraceto, Leonardo Fernandes
15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2), a peroxisome proliferator-activated receptor-γ (PPAR-γ) agonist, has physiological properties including pronounced anti-inflammatory activity, though it binds strongly to serum albumin. The use of solid lipid nanoparticles (SLN) can improve therapeutic properties increasing drug efficiency and availability. 15d-PGJ2-SLN was therefore developed and investigated in terms of its immunomodulatory potential. 15d-PGJ2-SLN and unloaded SLN were physicochemically characterized and experiments in vivo were performed. Animals were pretreated with 15d-PGJ2-SLN at concentrations of 3, 10 or 30 μg·kg-1 before inflammatory stimulus with carrageenan (Cg), lipopolysaccharide (LPS) or mBSA (immune response). Interleukins (IL-1β, IL-10 and IL-17) levels were also evaluated in exudates. The 15d-PGJ2-SLN system showed good colloidal parameters and encapsulation efficiency of 96%. The results showed that the formulation was stable for up to 120 days with low hemolytic effects. The 15d-PGJ2-SLN formulation was able to reduce neutrophil migration in three inflammation models tested using low concentrations of 15d-PGJ2. Additionally, 15d-PGJ2-SLN increased IL-10 levels and reduced IL-1β as well as IL-17 in peritoneal fluid. The new 15d-PGJ2-SLN formulation highlights perspectives of a potent anti-inflammatory system using low concentrations of 15d-PGJ2. PMID:27575486
Apaolaza, P S; Del Pozo-Rodríguez, A; Solinís, M A; Rodríguez, J M; Friedrich, U; Torrecilla, J; Weber, B H F; Rodríguez-Gascón, A
X-linked juvenile retinoschisis (XLRS) is a retinal degenerative disorder caused by mutations in the RS1 gene encoding a protein termed retinoschisin. The disease is an excellent candidate for gene replacement therapy as the majority of mutations have been shown to lead to a complete deficiency of the secreted protein in the retinal structures. In this work, we have studied the ability of non-viral vectors based on solid lipid nanoparticles (SLN) to induce the expression of retinoschisin in photoreceptors (PR) after intravitreal administration to Rs1h-deficient mice. We designed two vectors prepared with SLN, protamine, and dextran (DX) or hyaluronic acid (HA), bearing a plasmid containing the human RS1 gene under the control of the murin opsin promoter (mOPS). In vitro, the nanocarriers were able to induce the expression of retinoschisin in a PR cell line. After injection into the murine vitreous, the formulation prepared with HA induced a higher transfection level in PR than the formulation prepared with DX. Moreover, the level of retinoschisin in the inner nuclear layer (INL), where bipolar cells are located, was also higher. Two weeks after vitreal administration into Rs1h-deficient mice, both formulations showed significant improvement of the retinal structure by inducing a decrease of cavities and PR loss, and an increase of retinal and outer nuclear layer (ONL) thickness. HA-SLN resulted in a significant higher increase in the thickness of both retina and ONL, which can be explained by the higher transfection level of PR. In conclusion, we have shown the structural improvement of the retina of Rs1h-deficient mice with PR specific expression of the RS1 gene driven by the specific promoter mOPS, after successful delivery via SLN-based non-viral vectors.
Schöler, N; Olbrich, C; Tabatt, K; Müller, R H; Hahn, H; Liesenfeld, O
After intravenous (i.v.) injection, solid lipid nanoparticles (SLN) interact with mononuclear cells. Murine peritoneal macrophages were incubated with SLN formulations consisting of Dynasan 114 coated with different surfactants. The present study was performed to examine the impact of surfactants, which are important surface defining components of SLN, on viability and cytokine production by macrophages. Cytotoxicity, as assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) test, was strongly influenced by the surfactant used being marked with cetylpyridinium chloride- (CPC-) coated SLN at a concentration of 0.001% and further increased at SLN concentrations of 0.01 and 0.1%. All other SLN formulations -- containing Poloxamine 908 (P908), Poloxamer 407 (P407), Poloxamer 188 (P188), Solutol HS15 (HS15), Tween 80 (T80), Lipoid S75 (S75), sodium cholate (SC), or sodium dodecylsulfate (SDS) -- when used at the same concentrations reduced cell viability only slightly. None of the SLN formulations tested induced cytokine production but a concentration-dependent decrease of IL-6 production was observed, which appeared to be associated with cytotoxic effects. IL-12 and TNF-alpha were detected neither in supernatants of macrophages treated with SLN at any concentration nor in those of untreated cells. In contrast to the type of surfactant, the size of SLN was found neither to affect cytotoxicity of SLN nor to result in induction or digression of cytokine production by macrophages. In conclusion, testing the effects of surfactants on SLN on activity of macrophages is a prerequisite prior to in vivo use of SLN.
Wang, Wenrui; Zhu, Rongrong; Xie, Qian; Li, Ang; Xiao, Yu; Li, Kun; Liu, Hui; Cui, Daxiang; Chen, Yihan; Wang, Shilong
Curcumin has shown considerable pharmacological activity, including anti-inflammatory, but its poor bioavailability and rapid metabolization have limited its application. The purpose of the present study was to formulate curcumin-solid lipid nanoparticles (curcumin-SLNs) to improve its therapeutic efficacy in an ovalbumin (OVA)-induced allergic rat model of asthma. A solvent injection method was used to prepare the curcumin-SLNs. Physiochemical properties of curcumin-SLNs were characterized, and release experiments were performed in vitro. The pharmacokinetics in tissue distribution was studied in mice, and the therapeutic effect of the formulation was evaluated in the model. The prepared formulation showed an average size of 190 nm with a zeta potential value of −20.7 mV and 75% drug entrapment efficiency. X-ray diffraction analysis revealed the amorphous nature of the encapsulated curcumin. The release profile of curcumin-SLNs was an initial burst followed by sustained release. The curcumin concentrations in plasma suspension were significantly higher than those obtained with curcumin alone. Following administration of the curcumin-SLNs, all the tissue concentrations of curcumin increased, especially in lung and liver. In the animal model of asthma, curcumin-SLNs effectively suppressed airway hyperresponsiveness and inflammatory cell infiltration and also significantly inhibited the expression of T-helper-2-type cytokines, such as interleukin-4 and interleukin-13, in bronchoalveolar lavage fluid compared to the asthma group and curcumin-treated group. These observations implied that curcumin-SLNs could be a promising candidate for asthma therapy. PMID:22888226
Mojahedian, Mohammad M; Daneshamouz, Saeid; Samani, Soliman Mohammadi; Zargaran, Arman
Solid Lipid Nanoparticles (SLN) and Nanostructured Lipid Carriers (NLC) are novel medicinal carriers for controlled drug release and drug targeting in different roots of administration such as parenteral, oral, ophthalmic and topical. These carriers have some benefits such as increased drug stability, high drug payload, the incorporation of lipophilic and hydrophilic drugs, and no biotoxicity. Therefore, due to the cost-efficient, proportionally increasable, and reproducible preparation of SLN/NLC and the avoidance of organic solvents used, the warm microemulsion quenching method was selected from among several preparation methods for development in this research. To prepare the warm O/W microemulsion, lipids (distearin, stearic acid, beeswax, triolein alone or in combination with others) were melted at a temperature of 65°C. After that, different ratios of Tween60 (10-22.5%) and glyceryl monostearate (surfactant and co-surfactant) and water were added, and the combination was stirred. Then, 1-butanol (co-surfactant) was added dropwise until a clear microemulsion was formed and titration continued to achieve cloudiness (to obtain the microemulsion zone). The warm o/w microemulsions were added dropwise into 4°C water (1:5 volume ratio) while being stirred at 400 or 600 rpm. Lipid nanosuspensions were created upon the addition of the warm o/w microemulsion to the cold water. The SLN were obtained over a range of concentrations of co-surfactants and lipids and observed for microemulsion stability (clearness). For selected preparations, characterization involved also determination of mean particle size, polydispersity and shape. According to the aim of this study, the optimum formulations requiring the minimum amounts of 1-butanol (1.2%) and lower temperatures for creation were selected. Mono-disperse lipid nanoparticles were prepared in the size range 77 ± 1 nm to 124 ± 21 nm according to a laser diffraction particle size analyzer and transmission electron
Apaolaza, Paola Stephanie; Delgado, Diego; del Pozo-Rodríguez, Ana; Gascón, Alicia Rodríguez; Solinís, M Ángeles
The introduction of therapeutic genes in target tissues is considered as a novel tool for the treatment of several diseases. We have developed nanoparticles consisting on SLNs, protamine (P) and hyaluronic acid (HA) as carrier for gene therapy. Stable complexes positively charged and with a particle size ranging from 240 nm to 340 nm were obtained. Transfection studies in ARPE-19 and HEK-293 cells showed the versatility of vectors to efficiently transfect cells with different division rate, widening the potential applications of SLN-based vectors. In ARPE 19cells, the incorporation of P and HA induced almost a 7-fold increase in the transfection capacity of SLNs. The CD44 inhibition studies suggested the participation of this receptor in the internalization of the vectors in this cell line. The intracellular disposition of DNA showed that the HA is able to modulate the high degree of condensation of DNA due to the protamine inside the cells; an important fact, if the vector is uptaken via non-degradative endocytosis. Besides, the therapeutic plasmid which encodes the protein retinoschisin was employed achieving a positive transfection in ARPE-19 cells, showing a promising application of this new non-viral system for the treatment of X-linked juvenile retinoschisis by gene therapy.
Fàbregas, Anna; Sánchez-Hernández, Noemí; Ticó, Josep Ramon; García-Montoya, Encarna; Pérez-Lozano, Pilar; Suñé-Negre, Josep M; Hernández-Munain, Cristina; Suñé, Carlos; Miñarro, Montserrat
Solid lipid nanoparticles (SLNs) are being considered as a new approach for therapeutics for many known diseases. In addition to drug delivery, their use as non-viral vectors for gene delivery can be achieved by the inclusion of cationic lipids, which provide a positive surface potential that favours binding to the DNA backbone. This work is based on the idea that the optimization of the components is required as the first step in simplifying the qualitative and quantitative composition of SLNs as much as possible without affecting the essential properties that define SLNs as optimal non-viral vectors for gene delivery. We selected the best lipids and surfactants in terms of particle size and zeta potential and characterized the properties of the resulting nanoparticles using X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The SLNs had a particle size of approximately 120 nm and a positive surface charge of 42 mV. In addition, we analysed the main physicochemical characteristics of the bulk components of the nanoparticles using X-ray diffraction (XRD), differential scanning calorimetry (DSC) and mass spectrometry (MS). The suitability of the optimized SLNs for DNA binding was evaluated after the lyophilisation process using a carboxyl-terminal region of the TCERG1 gene, a human factor that has been implicated in several diseases. We show that the SLNs presented high efficiency in the binding of DNA, and importantly, they presented no toxicity when assayed in an in vivo system.
Systematic Approach for the Formulation and Optimization of Solid Lipid Nanoparticles of Efavirenz by High Pressure Homogenization Using Design of Experiments for Brain Targeting and Enhanced Bioavailability.
Gupta, Shweta; Kesarla, Rajesh; Chotai, Narendra; Misra, Ambikanandan; Omri, Abdelwahab
The nonnucleoside reverse transcriptase inhibitors, used for the treatment of HIV infections, are reported to have low bioavailability pertaining to high first-pass metabolism, high protein binding, and enzymatic metabolism. They also show low permeability across blood brain barrier. The CNS is reported to be the most important HIV reservoir site. In the present study, solid lipid nanoparticles of efavirenz were prepared with the objective of providing increased permeability and protection of drug due to biocompatible lipidic content and nanoscale size and thus developing formulation having potential for enhanced bioavailability and brain targeting. Solid lipid nanoparticles were prepared by high pressure homogenization technique using a systematic approach of design of experiments (DoE) and evaluated for particle size, polydispersity index, zeta potential, and entrapment efficiency. Particles of average size 108.5 nm having PDI of 0.172 with 64.9% entrapment efficiency were produced. Zeta potential was found to be -21.2 mV and the formulation was found stable. The in-vivo pharmacokinetic studies revealed increased concentration of the drug in brain, as desired, when administered through intranasal route indicating its potential for an attempt towards complete eradication of HIV and cure of HIV-infected patients.
Systematic Approach for the Formulation and Optimization of Solid Lipid Nanoparticles of Efavirenz by High Pressure Homogenization Using Design of Experiments for Brain Targeting and Enhanced Bioavailability
Gupta, Shweta; Kesarla, Rajesh; Chotai, Narendra; Misra, Ambikanandan
The nonnucleoside reverse transcriptase inhibitors, used for the treatment of HIV infections, are reported to have low bioavailability pertaining to high first-pass metabolism, high protein binding, and enzymatic metabolism. They also show low permeability across blood brain barrier. The CNS is reported to be the most important HIV reservoir site. In the present study, solid lipid nanoparticles of efavirenz were prepared with the objective of providing increased permeability and protection of drug due to biocompatible lipidic content and nanoscale size and thus developing formulation having potential for enhanced bioavailability and brain targeting. Solid lipid nanoparticles were prepared by high pressure homogenization technique using a systematic approach of design of experiments (DoE) and evaluated for particle size, polydispersity index, zeta potential, and entrapment efficiency. Particles of average size 108.5 nm having PDI of 0.172 with 64.9% entrapment efficiency were produced. Zeta potential was found to be −21.2 mV and the formulation was found stable. The in-vivo pharmacokinetic studies revealed increased concentration of the drug in brain, as desired, when administered through intranasal route indicating its potential for an attempt towards complete eradication of HIV and cure of HIV-infected patients. PMID:28243600
Venishetty, Vinay Kumar; Chede, Raghavendra; Komuravelli, Rojarani; Adepu, Laxminarayana; Sistla, Ramakrishna; Diwan, Prakash V
Solid lipid nanoparticles are most promising delivery systems for the enhancement of bioavailability of highly lipophilic drugs those prone to the first pass metabolism. But burst release of drug from solid lipid nanoparticles in acidic environment such as gastric milieu precludes its usage as oral delivery system. Studies on SLN revealed intraduodenal administration as an alternative route for SLN administration. But clinically it is an inappropriate route for repeated administration of drugs to patients. Hence, we prepared N-carboxymethyl chitosan (MCC) coated carvedilol loaded SLN to protect the rapid release of carvedilol in acidic environment. Positively charged carvedilol loaded SLN were developed using monoglyceride as lipid and soya lecithin and poloxamer 188 as surfactants and stearylamine as charge modifier. These SLN were characterized for particle size, zeta potential, entrapment efficiency, crystallinity and stability studies. Further these SLN were coated with N-carboxymethyl chitosan and confirmed by change in zetapotential and X-ray Photon Spectroscopic analysis. Effect of polymer coating on drug release profiles were studied simulated gastric and intestinal fluids. Effect of polymer coating on oral bioavailability of carvedilol loaded SLN were studied in rats after oral administration. MCC coated SLN improved the bioavailability of carvedilol compared uncoated SLN after oral administration. Insignificant difference in bioavailability was observed compared to intraduodenal administration of SLN. Hence, MCC coated SLN is a novel strategy to avoid intrduodenal administration.
Asnawi, Syalwati; Aziz, Azila A.; Aziz, Ramlan A.
A new delivery system for insect repellent is proposed by the incorporation of geranium oil into solid lipid nanoparticle (SLN). A variety of solvents which act as co-surfactants, were introduced to increase the particle size of GE-SLN. Ethanol, which has a high boiling point and a long chain alcohol produced larger particle than dichloromethane. The structure of SLN was not stable when methanol and acetone were used as co-solvents. Concentration of solvents can also influence the size of SLN. In vitro release experiments showed that SLN was able to reduce the rapid evaporation of geranium oil.
Das, Surajit; Kiong Ng, Wai; Tan, Reginald B. H.
This study focused on: (i) feasibility of the previously developed sucrose ester stabilized SLNs and NLCs to encapsulate different imidazole antifungal drugs and (ii) preparation and evaluation of topical gel formulations of those SLNs and NLCs. Three imidazole antifungal drugs; clotrimazole, ketoconazole and climbazole were selected for this study. The results suggested that size, size distribution and drug encapsulation efficiency depend on the drug molecule and type of nanoparticles (SLN/NLC). The drug release experiment always showed faster drug release from NLCs than SLNs when the same drug molecule was loaded in both nanoparticles. However, drug release rate from both SLNs and NLCs followed the order of climbazole > ketoconazole > clotrimazole. NLCs demonstrated better physicochemical stability than SLNs in the case of all drugs. The drug release rate from ketoconazole- and clotrimazole-loaded SLNs became faster after three months than a fresh formulation. There was no significant change in drug release rate from climbazole-loaded SLNs and all drug-loaded NLCs. Gel formulations of SLNs and NLCs were prepared using polycarbophil polymer. Continuous flow measurements demonstrated non-Newtonian flow with shear-thinning behavior and thixotropy. Oscillation measurements depicted viscoelasticity of the gel formulations. Similar to nanoparticle dispersion, drug release rate from SLN- and NLC-gel was in the order of climbazole > ketoconazole > clotrimazole. However, significantly slower drug release was noticed from all gel formulations than their nanoparticle counterparts. Unlike nanoparticle dispersions, no significant difference in drug release from gel formulations containing SLNs and NLCs was observed for each drug. This study concludes that gel formulation of imidazole drug-loaded SLNs and NLCs can be used for sustained/prolonged topical delivery of the drugs.
Das, Surajit; Ng, Wai Kiong; Tan, Reginald B H
This study focused on: (i) feasibility of the previously developed sucrose ester stabilized SLNs and NLCs to encapsulate different imidazole antifungal drugs and (ii) preparation and evaluation of topical gel formulations of those SLNs and NLCs. Three imidazole antifungal drugs; clotrimazole, ketoconazole and climbazole were selected for this study. The results suggested that size, size distribution and drug encapsulation efficiency depend on the drug molecule and type of nanoparticles (SLN/NLC). The drug release experiment always showed faster drug release from NLCs than SLNs when the same drug molecule was loaded in both nanoparticles. However, drug release rate from both SLNs and NLCs followed the order of climbazole > ketoconazole > clotrimazole. NLCs demonstrated better physicochemical stability than SLNs in the case of all drugs. The drug release rate from ketoconazole- and clotrimazole-loaded SLNs became faster after three months than a fresh formulation. There was no significant change in drug release rate from climbazole-loaded SLNs and all drug-loaded NLCs. Gel formulations of SLNs and NLCs were prepared using polycarbophil polymer. Continuous flow measurements demonstrated non-Newtonian flow with shear-thinning behavior and thixotropy. Oscillation measurements depicted viscoelasticity of the gel formulations. Similar to nanoparticle dispersion, drug release rate from SLN- and NLC-gel was in the order of climbazole > ketoconazole > clotrimazole. However, significantly slower drug release was noticed from all gel formulations than their nanoparticle counterparts. Unlike nanoparticle dispersions, no significant difference in drug release from gel formulations containing SLNs and NLCs was observed for each drug. This study concludes that gel formulation of imidazole drug-loaded SLNs and NLCs can be used for sustained/prolonged topical delivery of the drugs.
Gokce, Evren H; Korkmaz, Emrah; Tuncay-Tanrıverdi, Sakine; Dellera, Eleonora; Sandri, Giuseppina; Bonferoni, M Cristina; Ozer, Ozgen
Background The effective delivery of coenzyme Q10 (Q10) to the skin has several benefits in therapy for different skin pathologies. However, the delivery of Q10 to deeper layers of skin is challenging due to low aqueous solubility of Q10. Liposomes and solid lipid nanoparticles (SLN) have many advantages to accomplish the requirements in topical drug delivery. This study aims to evaluate the influence of these nanosystems on the effective delivery of Q10 into the skin. Methods Q10-loaded liposomes (LIPO-Q10) and SLNs (SLN-Q10) were prepared by thin film hydration and high shear homogenization methods, respectively. Particle size (PS), polydispersity index (PI), zeta potential (ZP), and drug entrapment efficiency were determined. Differential scanning calorimetry analysis and morphological transmission electron microscopy (TEM) examination were conducted. Biocompatibility/cytotoxicity studies of Q10-loaded nanosystems were performed by means of cell culture (human fibroblasts) under oxidative conditions. The protective effect of formulations against production of reactive oxygen species were comparatively evaluated by cytofluorometry studies. Results PS of uniform SLN-Q10 and LIPO-Q10 were determined as 152.4 ± 7.9 nm and 301.1 ± 8.2 nm, respectively. ZPs were −13.67 ± 1.32 mV and −36.6 ± 0.85 mV in the same order. The drug entrapment efficiency was 15% higher in SLN systems. TEM studies confirmed the colloidal size. SLN-Q10 and LIPO-Q10 showed biocompatibility towards fibroblasts up to 50 μM of Q10, which was determined as suitable for cell proliferation. The mean fluorescence intensity % depending on ROS production determined in cytofluorometric studies could be listed as Q10 ≥ SLN-Q10 > LIPO-Q10. Conclusion The LIPO-Q10 system was able to enhance cell proliferation. On the contrary, SLN-Q10 did not show protective effects against ROS accumulation. As a conclusion, liposomes seem to have advantages over SLN in terms of effective delivery of Q10 to skin
Preiss, Matthew Ryan
Novel liposome-nanoparticle assemblies (LNAs) provide a biologically inspired route for designing multifunctional bionanotheranostics. LNAs combine the benefits of lipids and liposomes to encapsulate, transport, and protect hydrophilic and hydrophobic therapeutics with functional nanoparticles. Functional nanoparticles endow LNAs with additional capabilities, including the ability to target diseases, triggered drug release, controlled therapeutic output, and diagnostic capabilities to produce a drug delivery system that can effectively and efficiently deliver therapeutics while reducing side effects. Not only could LNAs make existing drugs better, they could also provide an avenue to allow once promising non-approved drugs (rejected due to harmful side effects, inadequate pharmacokinetics, and poor efficacy) to be safely used through targeted and controlled delivery directly to the diseased site. LNAs have the potential to be stimuli responsive, delivering drugs on command by external (ultrasound, RF heating, etc.) or internal (pH, blood sugar, heart rate, etc.) stimuli. Individually, lipids and nanoparticles have been clinically approved for therapy, such as Doxil (a liposomal doxorubicin for cancer treatment), and diagnosis, such as Feridex (an iron oxide nanoparticle an MRI contrast enhancement agent for liver tumors). In order to engineer these multifunctional LNAs for theranostic applications, the interactions between nanoparticles and lipids must be better understood. This research sought to explore the formation, design, structures, characteristics, and functions of LNAs. To achieve this goal, different types of LNAs were formed, specifically magnetoliposomes, bilayer decorated LNAs (DLNAs), and lipid-coated magnetic nanoparticles (LMNPs). A fluorescent probe was embedded in the lipid bilayer of magnetoliposomes allowing the local temperature and membrane fluidity to be observed. When subjected to an electromagnetic field that heated the encapsulated iron
Cassano, Roberta; Ferrarelli, Teresa; Mauro, Maria Vittoria; Cavalcanti, Paolina; Picci, Nevio; Trombino, Sonia
The present article reports the preparation, characterization and performance evaluation of solid lipid nanoparticles (SLNs) based on polyoxyethylene-40 stearate (PEG-40 stearate) for the administration of antifungal agents such as ketoconazole and clotrimazole. These nanoparticles could be useful in the treatment of vaginal infections sustained by Candida albicans. In particular, PEG-40 stearate was made to react with acryloyl chloride in order to introduce an easily polymerizable moiety for the creation of a second shell and to ensure a slow drug release. In addition, the differences on the release profiles between PEG-40 stearate-based nanoparticles, PEG-40 stearate acrylate based and polymerized ones, were analyzed under conditions, simulating the typical environment of Candida albicans infection. Then, the antifungal activity of nanoparticles was also evaluated in terms of minimal inhibitory concentration. Moreover, the nanoparticles were submitted to in vitro studies for evaluating the drug permeability at the site of action. Results indicated that the obtained particles are potentially useful for the treatment of vaginal infections sustained by Candida albicans.
Shah, Brijesh; Khunt, Dignesh; Bhatt, Himanshu; Misra, Manju; Padh, Harish
In the present investigation, Quality by Design (QbD) approach was applied on the development and optimization of solid lipid nanoparticle (SLN) formulation of hydrophilic drug rivastigmine (RHT). RHT SLN were formulated by homogenization and ultrasonication method using Compritol 888 ATO, tween-80 and poloxamer-188 as lipid, surfactant and stabilizer respectively. The effect of independent variables (X1 - drug: lipid ratio, X2 - surfactant concentration and X3 - homogenization time) on quality attributes of SLN i.e. dependent variables (Y1 - size, Y2 - PDI and Y3 - %entrapment efficiency (%EE)) were investigated using 3(3) factorial design. Multiple linear regression analysis and ANOVA were employed to indentify and estimate the main effect, 2FI, quadratic and cubic effect. Optimized RHT SLN formula was derived from an overlay plot on which further effect of probe sonication was evaluated. Final RHT SLN showed narrow size distribution (PDI- 0.132±0.016) with particle size of 82.5±4.07 nm and %EE of 66.84±2.49. DSC and XRD study showed incorporation of RHT into imperfect crystal lattice of Compritol 888 ATO. In comparison to RHT solution, RHT SLN showed higher in-vitro and ex-vivo diffusion. The diffusion followed Higuchi model indicating drug diffusion from the lipid matrix due to erosion. Histopathology study showed intact nasal mucosa with RHT SLN indicating safety of RHT SLN for intranasal administration.
Ramachandran, Surekha; Thangarajan, Sumathi
Huntington's disease (HD), a devastating neurodegenerative disease causing a remarkable pathogenesis involves mitochondrial dysfunction and bioenergetics failure. 3-Nitropropionic acid (3-NP) is a unique toxin model of HD that are mainly confined to mitochondrial complex-II inhibition and free radical generation. Recently, several nanoparticle formulations were developed to treat against various neurodegenerative diseases including HD. One among them is solid lipid nanoparticles (SLNs), a colloidal carrier designed to enhance the brain drug delivery and to prolong the bio-availability of drugs in the system. Hence, the present study was framed to evaluate solid lipid nanoparticles encapsulated thymoquinone (TQ-SLNs) in comparison with thymoquinone suspension (TQ-S) against 3-NP induced behavioral despair, oxidative injury and striatal pathology. This study reports that theTQ-SLNs (10 and 20 mg/kg) and TQ-S (80 mg/kg) treated animals showed a significant (P < 0.01) improvement in the muscle strength, rigidity, movement and memory performances on 7th and 14th day behavioral analysis than TQ-S (40 mg/kg) treated group. Similarly, TQ-SLNs highly attenuated the levels of oxidative stress markers such as LPO, NO and protein carbonylsin 3-NP induced animals. Further, TQ-SLNs significantly restored the antioxidant defense system, controls the mitochondrial SDH inhibition and alleviates anti-cholinergic effect upon 3-NP induction. In addition, TQ-SLNs efficiently protected the striatal structural microelements against 3-NP toxicity, which was confirmed by light microscopic studies. Thus, the present investigation, collectively suggests that the low dose of TQ-SLNs supplementation is highly sufficient to attain the effect of TQ-S (80 mg/kg) to attenuate behavioral, biochemical and histological modifications in 3-NP exposed HD model.
Cassano, Roberta; Mellace, Silvia; Marrelli, Mariangela; Conforti, Filomena; Trombino, Sonia
The main target of this study was the preparation, characterization and antioxidant activity evaluation of α-tocopheryl linolenate based solid lipid nanoparticles (SLNs-TL), able to incorporate omega-3 α-linolenic acid, useful for the treatment of melanoma, a type of skin cancer. In particular, α-linolenic acid was successfully derivatized with α-tocopherol and the obtained compound was characterized by Fourier transform infrared (FT-IR) and by (1)H NMR to confirm the ester linkage. Both the empty SLNs-TL that SLNs-TL-LIN, containing omega-3-linolenic acid, were prepared through the technique of the microemulsion. The nanoparticles were characterized for entrapment efficiency, size and shape. Their antioxidant activity was investigated in rat liver microsomal membranes in inhibiting the lipid peroxidation induced by tert-butyl hydroperoxide (tert-BOOH), which endogenously produces alkoxyl radicals by Fenton reactions. The obtained results indicate that the α-tocopherol, linked by ester bond to α-linolenic acid, maintains an excellent antioxidant activity. The encapsulation efficiency was equal to 77% and the polydispersity index 0.198 indicating a good dimensional distribution. Furthermore, the nanoparticles were tested in vitro for their cytotoxic activity against human melanoma cancer cell line C32. Both empty SLNs-TL and loaded SLNs-TL-LIN showed a high biological activity, being more effective than α-linolenic acid and α-tocopherol. The results indicated that these nanoparticles could provide the delivery and the protection of unstable molecules, such as α-linolenic acid, from degradation induced by mechanisms of oxidative stress.
Wei, Lili; Yang, Yunfang; Shi, Kun; Wu, Jun; Zhao, Wei; Mo, Jingxin
The aim of the project was to assemble two optimum solid lipid nanoparticle (SLN) formulations for oral delivery of loperamide (LPM) to treat different types of diarrhea, and to evaluate their release profiles in vitro and pharmacokinetic properties in vivo. In this work, glyceryl trimyristate (Dynasan 114) nanoparticles containing the drug LPM and sodium cholate as a stabilizer were prepared using a modified solvent evaporation technique. Two LPM-loaded SLNs, namely LPM-SLN-1 (LPM-SLN with a high ratio rate of lipid to drug) and LPM-SLN-2 (LPM-SLN with a low ratio rate of lipid to drug), were prepared by the solvent evaporation method. A change in the lipid concentration affects the characteristics of LPM-SLNs. The average sizes of the LPM-SLNs were 303 ± 18 nm and 519 ± 36 nm, separately, as analyzed by dynamic light scattering. The LPM-SLNs were found to be round with a smooth surface, as observed using a transmission electron microscope and a scanning electron microscope. The average encapsulation efficiencies were 87 ± 3.78% w/w and 84 ± 5.17%, accordingly. In the in vitro release experiments, LPM-SLNs showed a continuous release profile of LPM without any burst release. The oral bioavailability of LPM-SLNs was analyzed using Wistar rats. The relative bioavailabilities of LPM-SLNs were 227 and 153%, respectively, as compared that of the LPM tablet. There was no difference in the Tmax between LPM-SLN-2 and the LPM tablet. In conclusion, LPM-SLN-1 significantly improved the oral bioavailability of LPM, while LPM-SLN-2 having the same swift action as the LPM tablet. These results demonstrate the potential of LPM-SLNs in the oral delivery of LPM to treat different types of diarrhea. PMID:27708583
Zhao, Yi; Huang, Leaf
Nonviral vectors which offer a safer and versatile alternative to viral vectors have been developed to overcome problems caused by viral carriers. However, their transfection efficacy or level of expression is substantially lower than viral vectors. Among various nonviral gene vectors, lipid nanoparticles are an ideal platform for the incorporation of safety and efficacy into a single delivery system. In this chapter, we highlight current lipidic vectors that have been developed for gene therapy of tumors and other diseases. The pharmacokinetic, toxic behaviors and clinic trials of some successful lipids particles are also presented. PMID:25409602
Yang, Caiqin; Lv, Jie; Lv, Tao; Pan, Yahui; Han, Yazhu; Zhao, Sha; Wang, Jing
Metal ion-assisted drug loading model, in which metal ion was used to modify the microstructure of lipid layer, has been developed to improve drug loading efficiency of solid lipid nanoparticles (SLNs). The microstructure and properties of metal ion-assisted cisplatin-loading SLNs were investigated by infra-red spectroscopy, fluorescence spectroscopy and zetasizer. The reactions of hydrogenated soybean lecithin with Zn(2+), Cu(2+), Mn(2+ )and Mg(2+ )have been detected; the mechanism for higher drug encapsulation efficiency (EE) has been investigated. In metal ion introduction SLNs, the compact degree of the lipid molecules was increased due to the electrostatic interaction between metal ions and phospholipid acyl and choline polarity groups, which result in increasing of drug EE. Meanwhile, these electrostatic interactions slowed the releasing rate of encapsulated drug. The study of cytotoxic activity in vitro indicated that the cell cytotoxicity of metal ions introduction SLNs depended on both cell uptake of SLNs and drug releasing from SLNs.
de Souza, Ana Luiza Ribeiro; Andreani, Tatiana; de Oliveira, Rosimeire Nunes; Kiill, Charlene Priscila; dos Santos, Fernanda Kolenyak; Allegretti, Silmara Marques; Chaud, Marco Vinícius; Souto, Eliana B; Silva, Amélia M; Gremião, Maria Palmira Daflon
Solid lipid nanoparticles (SLN) are a promising drug delivery system for oral administration of poorly-water soluble drugs because of their capacity to increase the solubility of drug molecules when loaded in their lipid matrices, with the resulting improvement of the drug bioavailability. In the present work, we have developed praziquantel (PZQ)-loaded SLN and explored the biological applications of this system for intestinal permeation of PZQ. The effect in vitro on Schistosoma mansoni culture and the cytotoxicity in HepG2 line cell were also evaluated. The results showed a significant decrease in the intestinal absorption of PZQ loaded in SLN compared to free PZQ, suggesting that the SLN matrix could act as reservoir system. In culture of S. mansoni, we observed that PZQ-loaded SLN were more effective than free PZQ, leading the death of the parasites in less time. The result was proportional to doses of PZQ (25 and 50 μg mL⁻¹) and lipid concentration. Regarding cytotoxicity, the encapsulation of PZQ into SLN decreased the toxicity in HepG2 cells in comparison to the free PZQ. From the obtained results, PZQ-loaded SLN could be a new drug delivery system for the schistosomiasis treatment especially in marginalized communities, improving the therapeutic efficacy and reducing the toxic effects of PZQ.
Tang, Jingling; Ji, Hongyu; Ren, Jinmei; Li, Mengting; Zheng, Nannan; Wu, Linhua
Multidrug resistance (MDR) is a main clinical hurdle for chemotherapy of cancer, and overexpression of P-glycoprotein (P-gp) is a key factor. In the present study, a new co-delivery system for reversing MDR was designed and developed. The system was composed of curcumin (Cur) and piperine (Pip) encapsulated in solid lipid nanoparticles (SLNs) with tocopheryl polyethylene glycol succinate (TPGS) and Brij 78 [(Cur+Pip)-SLNs]. TPGS and Brij 78 could sensitize MDR tumors by inhibiting the P-gp drug efflux system. The combination of Cur and Pip, when administered in SLNs formulations, resulted in a significant enhancement in cytotoxicity and allowed efficient intracellular delivery of the drugs in drug-resistant A2780/Taxol cells. This dual inhibitory strategy may have significant potential in the clinical management of MDR in cancer. PMID:28123572
Kulbacka, Julita; Pucek, Agata; Wilk, Kazimiera Anna; Dubińska-Magiera, Magda; Rossowska, Joanna; Kulbacki, Marek; Kotulska, Małgorzata
Drug delivery technology is still a dynamically developing field of medicine. The main direction in nanotechnology research (nanocarriers, nanovehicles, etc.) is efficient drug delivery to target cells with simultaneous drug reduction concentration. However, nanotechnology trends in reducing the carrier sizes to several nanometers limit the volume of the loaded substance and may pose a danger of uncontrolled access into the cells. On the other hand, nanoparticles larger than 200 nm in diameter have difficulties to undergo rapid diffusional transport through cell membranes. The main advantage of large nanoparticles is higher drug encapsulation efficiency and the ability to deliver a wider array of drugs. Our present study contributes a new approach with large Tween 80 solid lipid nanoparticles SLN (i.e., hydrodynamic GM-SLN-glycerol monostearate, GM, as the lipid and ATO5-SLNs-glyceryl palmitostearate, ATO5, as the lipid) with diameters DH of 379.4 nm and 547 nm, respectively. They are used as drug carriers alone and in combination with electroporation (EP) induced by millisecond pulsed electric fields. We evaluate if EP can support the transport of large nanocarriers into cells. The study was performed with two cell lines: human colon adenocarcinoma LoVo and hamster ovarian fibroblastoid CHO-K1 with coumarin 6 (C6) as a fluorescent marker for encapsulation. The biological safety of the potential treatment procedure was evaluated with cell viability after their exposure to nanoparticles and EP. The EP efficacy was evaluated by FACS method. The impact on intracellular structure organization of cytoskeleton was visualized by CLSM method with alpha-actin and beta-tubulin. The obtained results indicate low cytotoxicity of both carrier types, free and loaded with C6. The evaluation of cytoskeleton proteins indicated no intracellular structure damage. The intracellular uptake and accumulation show that SLNs do not support transport of C6 coumarin. Only application of
Mardhiah Adib, Zahra; Ghanbarzadeh, Saeed; Kouhsoltani, Maryam; Yari Khosroshahi, Ahmad; Hamishehkar, Hamed
Purpose: In the present study the effect of particle size, as a substantial parameters in skin penetration, on the deposition depth and rate of SLNs in different layers of skin was explored. Methods: SLNs in different particle size ranges (80, 333 and 971 nm) made of Precirol as solid lipid were prepared using hot melt homogenization technique and pigmented by Rhodamine B to be able to be tracked in the skin under inspection of fluorescent microscopy. After 0.5 h, 3 h, 6 h and 24 h of SLNs administration on rat skin, animals were sacrificed and exercised skins were sliced by a freeze microtome. SLNs were monitored in the skin structure under fluorescence microscope. Results: The size of SLNs played a crucial role in the penetration to deep skin layers. The sub100 nm size range of SLNs showed the most promising skin penetration rate and depth mainly via hair follicles. Conclusion: The results of the present study indicated that the selection of an appropriate size of particles may be a valuable factor impacting the therapeutic outcomes of dermal drug administration. PMID:27123415
He, Xiaolie; Zhu, Yanjing; Wang, Mei; Jing, Guoxin; Zhu, Rongrong; Wang, Shilong
Major depression is a complex neuropsychiatric disorder with few treatment approaches. The use of nontargeted antidepressants induced many side effects with their low efficacy. A more precise targeting strategy is to develop nanotechnology-based drug delivery systems; hence, we employed solid lipid nanoparticles (SLNs) to encapsulate HU-211 and curcumin (Cur). The antidepressant effects of the dual-drug nanoparticles (Cur/SLNs-HU-211) for major depression treatment were investigated in corticosterone-induced cellular and animal models of major depression. Cur/SLNs-HU-211 can effectively protect PC12 cells from corticosterone-induced apoptosis and can release more dopamine, which may be associated with the higher uptake of Cur/SLNs-HU-211 shown by cellular uptake behavior analysis. Additionally, Cur/SLNs-HU-211 significantly reduced the immobility time in forced swim test, enhanced fall latency in rotarod test, and improved the level of dopamine in mice blood. Cur/SLNs-HU-211 can deliver more Cur to the brain and thus produce a significant increase in neurotransmitters level in brain tissue, especially in the hippocampus and striatum. The results of Western blot and immunofluorescence revealed that Cur/SLNs-HU-211 can significantly enhance the expression of CB1, p-MEK1, and p-ERK1/2. Our study suggests that Cur/SLNs-HU-211 may have great potential for major depression treatment.
He, Xiaolie; Zhu, Yanjing; Wang, Mei; Jing, Guoxin; Zhu, Rongrong; Wang, Shilong
Major depression is a complex neuropsychiatric disorder with few treatment approaches. The use of nontargeted antidepressants induced many side effects with their low efficacy. A more precise targeting strategy is to develop nanotechnology-based drug delivery systems; hence, we employed solid lipid nanoparticles (SLNs) to encapsulate HU-211 and curcumin (Cur). The antidepressant effects of the dual-drug nanoparticles (Cur/SLNs-HU-211) for major depression treatment were investigated in corticosterone-induced cellular and animal models of major depression. Cur/SLNs-HU-211 can effectively protect PC12 cells from corticosterone-induced apoptosis and can release more dopamine, which may be associated with the higher uptake of Cur/SLNs-HU-211 shown by cellular uptake behavior analysis. Additionally, Cur/SLNs-HU-211 significantly reduced the immobility time in forced swim test, enhanced fall latency in rotarod test, and improved the level of dopamine in mice blood. Cur/SLNs-HU-211 can deliver more Cur to the brain and thus produce a significant increase in neurotransmitters level in brain tissue, especially in the hippocampus and striatum. The results of Western blot and immunofluorescence revealed that Cur/SLNs-HU-211 can significantly enhance the expression of CB1, p-MEK1, and p-ERK1/2. Our study suggests that Cur/SLNs-HU-211 may have great potential for major depression treatment. PMID:27757031
Liu, Bo; Han, Li; Liu, Junyan; Han, Shumei; Chen, Zhen; Jiang, Lixi
Background Cervical cancer is a major world health problem for women. Currently, cancer research focuses on improving therapy for cervical cancer using various treatment options such as co-delivery of chemotherapeutic agents by nanocarriers. Purpose The aim of this study was to develop trans-activating transcriptional activator (TAT)-modified solid lipid nanoparticles (SLNs) for co-delivery of paclitaxel (PTX) and α-tocopherol succinate-cisplatin prodrug (TOS-CDDP) (TAT PTX/TOS-CDDP SLNs) in order to achieve synergistic antitumor activity against cervical cancer. Methods Lipid prodrug of CDDP (TOS-CDDP) and TAT-containing polyethylene glycol-distearoyl-phosphatidylethanolamine (TAT-PEG-DSPE) were synthesized. TAT PTX/TOS-CDDP SLNs were prepared by emulsification and solvent evaporation method. Physicochemical characteristics of SLNs such as size, morphology, and release profiles were explored. In vitro and in vivo studies were carried out to assess the efficacy of their antitumor activity in target cells. Results TAT PTX/TOS-CDDP SLNs could be successfully internalized by HeLa cells and showed a synergistic effect in the suppression of cervical tumor cell growth. They exhibited high tumor tissue accumulation, superior antitumor efficiency, and much lower toxicity in vivo. Conclusion The present study indicates that the co-delivery system provides a promising platform as a combination therapy for the treatment of cervical cancer, and possibly other types of cancer as well. PMID:28203075
Barua, Sonia; Kim, Hyeongmin; Hong, Seong-Chul; Yoo, Seung-Yup; Shin, Dohyun; Lee, Chung-Lyol; Na, Seon-Jeong; Kim, Yeong Hyo; Jo, Kanghee; Yun, Gyiae; Kim, Joong-Hark; Sohn, Uy Dong; Lee, Jaehwi
This study evaluated the moisturizing effect of serine-loaded solid lipid nanoparticles (serine-SLN) and polysaccharide-rich reed (Phragmites communis) root extract (RRE) incorporated in hydrogel bases. The hydrogels with serine-SLN and/or RRE were carefully applied on the volar forearm of human volunteers. Their moisturizing efficacy was evaluated by monitoring conductance values using a skin surface hygrometer. The values of the area under the normalized conductance-time curve (AUCC) were developed and compared as a parameter for the water holding capacity of the skin. Hydrogels with serine-SLN did not significantly moisturize the skin, while hydrogel containing 0.25% RRE produced a significant increase in the moisture content of the skin. However, adding more than 0.25% of RRE into the hydrogel base decreased the moisturizing effect due to the marked reduction of viscosity. Significantly enhanced moisturizing effect was observed with the hydrogel containing 0.25% RRE and 3% serine-SLN, with AUCC increased 2.21 times compared to than blank hydrogel. The results imply that effective delivery of serine into the skin is possible using lipid-based nanocarriers and RRE, which could be a promising strategy to moisturize the skin effectively.
Application of Box-Behnken design for preparation of levofloxacin-loaded stearic acid solid lipid nanoparticles for ocular delivery: Optimization, in vitro release, ocular tolerance, and antibacterial activity.
Baig, Mirza Salman; Ahad, Abdul; Aslam, Mohammed; Imam, Syed Sarim; Aqil, Mohd; Ali, Asgar
The aim of the present study was to develop and optimize levofloxacin loaded solid lipid nanoparticles for the treatment of conjunctivitis. Box-Behnken experimental design was applied for optimization of solid lipid nanoparticles. The independent variables were stearic acid as lipid (X1), Tween 80 as surfactant (X2) and sodium deoxycholate as co-surfactant (X3) while particle size (Y1) and entrapment efficiency (Y2) were the dependent variables. Further in vitro release and antibacterial activity in vitro were also performed. The optimized formulation of levofloxacin provides particle size of 237.82 nm and showed 78.71% entrapment efficiency and achieved flux 0.2,493 μg/cm(2)/h across excised goat cornea. In vitro release study showed prolonged drug release from the optimized formulation following Korsmeyer-Peppas model. Antimicrobial study revealed that the developed formulation possesses antibacterial activity against Staphylococcus aureus, and Escherichia coli equivalent to marketed eye drops. HET-CAM test demonstrated that optimized formulation was found to be non-irritant and safe for topical ophthalmic use. Our results concluded that solid lipid nanoparticles are an efficient carrier for ocular delivery of levofloxacin and other drugs.
Chen, Hsin-Hung; Huang, Wen-Chia; Chiang, Wen-Hsuan; Liu, Te-I; Shen, Ming-Yin; Hsu, Yuan-Hung; Lin, Sung-Chyr; Chiu, Hsin-Cheng
In this study, a novel pH-responsive cholesterol-PEG adduct-coated solid lipid nanoparticles (C-PEG-SLNs) carrying doxorubicin (DOX) capable of overcoming multidrug resistance (MDR) breast cancer cells is presented. The DOX-loaded SLNs have a mean hydrodynamic diameter of ~100 nm and a low polydispersity index (under 0.20) with a high drug-loading efficiency ranging from 80.8% to 90.6%. The in vitro drug release profiles show that the DOX-loaded SLNs exhibit a pH-controlled drug release behavior with the maximum and minimum unloading percentages of 63.4% at pH 4.7 and 25.2% at pH 7.4, respectively. The DOX-loaded C-PEG-SLNs displayed a superior ability in inhibiting the proliferation of MCF-7/MDR cells. At a DOX concentration of 80 μM, the cell viabilities treated with C-PEG-SLNs were approximately one-third of the group treated with free DOX. The inhibition activity of C-PEG-SLNs could be attributed to the transport of C-PEG to cell membrane, leading to the change of the composition of the cell membrane and thus the inhibition of permeability glycoprotein activity. This hypothesis is supported by the confocal images showing the accumulation of DOX in the nuclei of cancer cells and the localization of C-PEG on the cell membranes. The results of in vivo study further demonstrated that the DOX delivered by the SLNs accumulates predominantly in tumor via enhanced permeability and retention effect, the enhanced passive tumor accumulation due to the loose intercellular junctions of endothelial cells lining inside blood vessels at tumor site, and the lack of lymphatic drainage. The growth of MCF-7/MDR xenografted tumor on Balb/c nude mice was inhibited to ~400 mm(3) in volume as compared with the free DOX treatment group, 1,140 mm(3), and the group treated with 1,2 distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)] solid lipid nanoparticles, 820 mm(3). Analysis of the body weight of nude mice and the histology of organs and tumor after the
Doroud, Delaram; Zahedifard, Farnaz; Vatanara, Alireza; Taslimi, Yasaman; Vahabpour, Rouholah; Torkashvand, Fatemeh; Vaziri, Behrooz; Rouholamini Najafabadi, Abdolhossein; Rafati, Sima
Background We have demonstrated that vaccination with pDNA encoding cysteine proteinase Type II (CPA) and Type I (CPB) with its unusual C-terminal extension (CTE) can partially protect BALB/c mice against cutaneous leishmanial infection. Unfortunately, this protection is insufficient to completely control infection without booster injection. Furthermore, in developing vaccines for leishmaniasis, it is necessary to consider a proper adjuvant and/or delivery system to promote an antigen specific immune response. Solid lipid nanoparticles have found their way in drug delivery system development against intracellular infections and cancer, but not Leishmania DNA vaccination. Therefore, undefined effect of cationic solid lipid nanoparticles (cSLN) as an adjuvant in enhancing the immune response toward leishmanial antigens led us to refocus our vaccine development projects. Methodology/Principal Findings Three pDNAs encoding L. major cysteine proteinase type I and II (with or without CTE) were formulated by cSLN. BALB/c mice were immunized twice by 3-week interval, with cSLN-pcDNA-cpa/b, pcDNA-cpa/b, cSLN-pcDNA-cpa/b-CTE, pcDNA-cpa/b-CTE, cSLN, cSLN-pcDNA and PBS. Mice vaccinated with cSLN-pcDNA-cpa/b-CTE showed significantly higher levels of parasite inhibition related to protection with specific Th1 immune response development, compared to other groups. Parasite inhibition was determined by different techniques currently available in exploration vacciation efficacy, i.e., flowcytometry on footpad and lymph node, footpad caliper based measurements and imaging as well as lymph node microtitration assay. Among these techniques, lymph node flowcytometry was found to be the most rapid, sensitive and easily reproducible method for discrimination between the efficacy of vaccination strategies. Conclusions/Significance This report demonstrates cSLN's ability to boost immune response magnitude of cpa/cpb-CTE cocktail vaccination against leishmaniasis so that the average
Soares, Sandra; Fonte, Pedro; Costa, Ana; Andrade, José; Seabra, Vítor; Ferreira, Domingos; Reis, Salette; Sarmento, Bruno
This study aims to monitor the secondary structure behaviour of insulin when it is encapsulated into solid lipid nanoparticles (SLN), under the influence of several critical processing parameters. Insulin was used as a therapeutic protein model. Physicochemical properties of insulin-loaded SLN (Ins-SLN) were assessed, with special focus on the insulin secondary structure after its encapsulation into SLN and after freeze-drying using different cryoprotectants (glucose, fructose and sorbitol). Additionally, a 6-month stability study was performed to evaluate the maintenance of insulin secondary structure over time at different storage conditions (4 °C/60% RH, 25 °C/60% RH, 40 °C/75% RH). Ins-SLN were successfully produced with a mean and narrow particle size around 400 nm, zeta potential around -13 mV, an insulin association efficiency of 84%. Physical-chemical properties of SLN were maintained after freeze-drying. FTIR results showed that encapsulated insulin maintained a native-like structure in a degree of similarity around 92% after production, and 84% after freeze-drying. After 6 months, freeze-dried Ins-SLN without cryoprotectant stored at 40 °C/75% RH presented the same degree of structure preservation and morphology. Results revealed that insulin structure can be significantly protected by SLN matrix itself, without a cryoprotectant agent, even using a non-optimized freeze-drying process, and under the harsher storage conditions. Multivariable experimental settled the process parameters to fit with the desired product quality attributes regarding protein and nanoparticle stability.
Zoubari, Gaith; Staufenbiel, Sven; Volz, Pierre; Alexiev, Ulrike; Bodmeier, Roland
Lipid nanoparticles have gained increased interest in the field of dermal products because of various advantages such as improved drug absorption and controlled drug release. The main objective was to investigate the influence of drug solubility and type of lipid carrier on the in vitro drug release. Drugs of different solubilities in the release medium PBS pH 7.4 (dexamethasone: 0.1mg/ml and diclofenac sodium: 5.0mg/ml) and three different lipids (in which the drugs had the highest solubility), Gelucire® 50/13 (solid lipid, mp: 50°C), Witepsol® S55 (solid lipid, mp: 33.5-35.5°C) and Capryol® 90 (liquid lipid) were chosen. The lipid nanoparticles were prepared by high shear homogenization. All nanosuspensions were in the nanometer range (up to 400nm) and the drug encapsulation efficiency was between 84% and 95%. The drug release was prolonged over 48h without an initial burst release and was dependent on the lipid carrier. Formulations containing a higher amount of solid Gelucire® 50/13 released the drugs slower due to the high affinity of the drugs to this lipid product. Inclusion of the liquid lipid Capryol® 90 resulted in a less organized lipidic structures (softer particles) and therefore a faster drug release. Despite its higher water solubility, diclofenac was released slower than dexamethasone because of its higher solubility in the lipid carriers. DSC studies indicated a partial miscibility between the solid lipids and a good miscibility between the solid and liquid lipids. Primary studies using total internal reflection fluorescence (TIRF) microscopy indicated that it is possible to detect individual fluorescently labeled dexamethasone (DXM-F) molecules dissolved in the liquid lipid Capryol® 90. These studies will allow for the precise determination of the drug distribution within the lipid carrier, and the changes upon drug release. In conclusion, lipid carrier type and drug solubility in the lipid have a large influence on the in vitro drug
Wang, Fang; Li, Li; Liu, Bo; Chen, Zhen; Li, Changzhong
This work aimed to develop hyaluronic acid (HA) decorated pluronic 85 (P85) coated solid lipid nanoparticles (SLN) loaded with paclitaxel (HA-PTX-P85-SLN) and to evaluate its potential to overcome drug resistance and to increase antitumor efficacy in mice bearing cervical and breast tumor. P85-Distearoyl Phosphoethanolamine (DSPE) was synthesized from P85 and DSPE by coupling in the presence of 1,10-carbonyldiimidazole (CDI) as a catalyst. The SLN were prepared by the hot homogenization technique and electrostatic interaction. PTX-loaded SLN was characterized for mean diameter, zeta potential, morphology, entrapment efficiency (EE), drug loading capacity (LC) and in vitro drug release. In vivo animal evaluation containing antitumor effect, pharmacokinetics and biodistribution were conducted in mice bearing cervical and breast tumor. The HA-PTX-P85-SLN showed a mean diameter of 160.3nm, negative zeta potential (-31.6mV), EE of 88.2%, and LC of 4.9%. PTX from HA-PTX-P85-SLN exhibited greater sustained drug release profiles compared free PTX. Pharmacokinetics results indicated that HA-PTX-P85-SLN exhibited a 5.5-fold increase in AUC in comparison to free PTX. Biodistribution results revealed that HA-PTX-P85-SLN exhibited higher tumor drug concentration compared with free PTX.
Kakkar, Vandita; Singh, Sukhjeet; Singla, Dinesh; Sahwney, Sudhir; Chauhan, Anurag Singh; Singh, Gangandeep; Kaur, Indu Pal
A simple and sensitive validated LC-MS/MS analytical method was used for determination of curcumin in rat plasma, using nimesulide as internal standard. Analyses were performed on an Agilent LC-MS/MS system using a Chromolith rod™ and isocratic elution with acetonitrile:10 mM ammonium acetate buffer (pH 3.5) (80:20, v/v) at a flow rate of 0.8 ml/min with a total run time of 3 min and an overall recovery of 77.15%. A triple quadrupole mass spectrometer, equipped with an electrospray ionization interface, operated in the negative mode was used. Calibration curve in plasma spiked with varying concentration of curcumin were linear over the concentration range of 10-2000 ng/ml with determination coefficient >0.99. The lower limit of quantification was 10 ng/ml. Intra and inter-day variability's (RSD) for extraction of curcumin from plasma were less than 10% and 15% respectively and accuracy was 102.43-108.5%. Multiple reaction monitoring was used to monitor the transition for curcumin (m/z; 367/217 [M-H](-)) and IS (m/z; 307/229). The method was applied for determining curcumin concentration in plasma after peroral administration of 50 mg/kg of free curcumin (C-S) or curcumin loaded solid lipid nanoparticles (C-SLNs) to rats. Results established selectivity and suitability of the method for pharmacokinetic studies of curcumin from C-SLNs.
Wang, Ping; Zhang, Libin; Peng, Hao; Li, Yongwu; Xiong, Jian; Xu, Zheyuan
Curcumin was determined to have anticancer potency on several kinds of carcinoma. However, its medical application was limited because of its poor bioavailability, unsatisfying dispersity and rapid metabolism in vivo. In this study, curcumin was delivered by solid lipid nanoparticles (SLN) for lung cancer treatment. The physiochemical characters of SLN-curcumin were detected by HPLC, TEM, Zeta potential analysis and FTIR, and the anticancer efficiency on lung cancer was determined both in vitro and in vivo. SLN-curcumin was synthesized by sol-gel method with the size ranged from 20 to 80 nm. After being loaded in SLN, the IC50 of SLN-curcumin on A549 cells was 4 μM, only 1/20 of plain drug. The plasmid concentration of curcumin was highly increased in mice via i.p. after loaded with SLN. Furthermore, SLN-curcumin enhanced the targeting of curcumin to lung and tumor, which finally increased the inhibition efficiency of curcumin from 19.5% to 69.3%. The Flow Cytometry (FCM) analysis and immuno staining confirmed that the inhibition effect mostly came from apoptosis, but not necrosis. The tumor targeting and profound tumor inhibition effect of SLN-curcumin indicated its medical application on lung cancer treatment, and also provided a novel method for new anticancer agents' development.
Gandomi, Nargess; Varshochian, Reyhaneh; Atyabi, Fatemeh; Ghahremani, Mohammad Hossein; Sharifzadeh, Mohammad; Amini, Mohsen; Dinarvand, Rassoul
Multiple sclerosis (MS) is a chronic central nervous system (CNS) inflammation. Efficient drug delivery to brain is however hampered by blood-brain barrier (BBB). In order to have highly efficient and safe delivery of drugs to brain, solid lipid nanoparticles (SLNs) have indicated promising potentials as smart carriers that can pass the blood-brain barrier and deliver therapeutic biomolecules to the brain. In this study, PEGylated SLNs surface modified using anti-Contactin-2 or anti-Neurofascin, two axo-glial-glycoprotein antigens located in node of Ranvier, were prepared. These targeting moieties are considered as the main targets of autoimmune reaction in MS. The targeted SLNs were then characterized and their in vitro release profile together with their cell viability and uptake were studied. Their brain uptakes were also probed following injections in MS-induced mice. It was found that the targeted PEGylated SLNs had no significant cytotoxicity on U87MG cells although their cellular uptake was increased 4- and 8-fold when surface modified with anti-Contactin-2 or anti-Neurofascin, respectively, compared to control. Brain uptake results demonstrated higher uptake of surface-modified SLNs in the brain tissue compared with the PEGylated SLNs. The results of this report will help scientist to design more efficient nanocarriers for treatment of MS.
Meng, Xiang-Ping; Wang, Xiao; Wang, Huai-ling; Chen, Tong-sheng; Wang, Yi-fei; Wang, Zhi-ping
Hepatocarcinoma and esophageal squamous cell carcinomas threaten human life badly. It is a current issue to seek the effective natural remedy from plant to treat cancer due to the resistance of the advanced hepatocarcinoma and esophageal carcinoma to chemotherapy. Berberine (Ber), an isoquinoline derivative alkaloid, has a wide range of pharmacological properties and is considered to have anti-hepatocarcinoma and antiesophageal carcinoma effects. However its low oral bioavailability restricts its wide application. In this report, Ber loaded solid lipid nanoparticles (Ber-SLN) was prepared by hot melting and then high pressure homogenization technique. The in vitro anti-hepatocarcinoma and antiesophageal carcinoma effects of Ber-SLN relative to efficacy of bulk Ber were evaluated. The particle size and zeta potential of Ber-SLN were 154.3 ± 4.1 nm and -11.7 ± 1.8 mV, respectively. MTT assay showed that Ber-SLN effectively inhibited the proliferation of human HepG2 and Huh7 and EC9706 cells, and the corresponding IC50 value was 10.6 μg/ml, 5.1 μg/ml, and 7.3 μg/ml (18.3μg/ml, 6.5μg/ml, and 12.4μg/ml μg/ml of bulk Ber solution), respectively. These results suggest that the delivery of Ber-SLN is a promising approach for treating tumors.
Using a homogenization-evaporation method, beta-carotene (BC) loaded nano-particles were prepared with different ratios of food-grade sodium caseinate (SC), whey protein isolate (WPI), or soy protein isolate (SPI) to BC and evaluated for their physiochemical stability, in vitro cytotoxicity, and cel...
Heider, Martha; Hause, Gerd; Mäder, Karsten
Enzymatic digestion of lipid drug carriers is very important. Commonly, pancreatin induced formation of fatty acids is monitored by the pH-stat method, which provides a fast, but unspecific readout. However, according to the literature, the pKa values of long chain fatty acids are strongly dependent on the local environment and might vary between 4.2 and 10.15. The high pKa values would lead to an incomplete detection of the lipid digestion and false results. In order to investigate these issues in more detail, we produced cetyl palmitate solid lipid nanoparticles (CP-SLN) stabilized with poloxamer 188 or polysorbate 80. The digestion of CP-SLN was investigated by two different and independent readouts. A HPTLC assay was used in addition to the pH-stat method (with or without back titration). An incomplete digestion of CP-SLN was observed with all methods. Partial digestion of polysorbate 80 contributed to the formation of fatty acids. Depending on the investigated system and the experimental conditions (FaSSIF or FeSSIF) the results of both readout methods were comparable or not. For example, in FeSSIF conditions, the values detected by HPTLC were roughly twice as high as the pH-stat results. Our findings on solid lipids agree with data from Helbig et al. on lipid emulsions, where a gas chromatography method detected much higher values than the pH-stat assay (Food Hydrocoll. 28 (2012) 10-19). The results of our pH-stat experiments with back titration at different pH values showed increased values for fatty acids from pH 7.5 to pH 10. The values obtained by back titration at high pH values (pH 9 or higher) did exceed the digestion values measured by HPTLC. Therefore, we conclude that the pH-stat method might give the same results as more specific reference methods, but it might also both under- (without back titration) or overestimate (with back titration) the enzymatic digestion of lipid drug delivery systems. A further outcome of our study was the proof that
de Jesus, Marcelo Bispo; Radaic, Allan; Zuhorn, Inge S.; de Paula, Eneida
Solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) have been intensively investigated for different applications, including their use as drug and gene delivery systems. Different techniques have been employed to produce lipid nanoparticles, of which high pressure homogenization is the standard technique that is adopted nowadays. Although this method has a high efficiency, does not require the use of organic solvents, and allows large-scale production, some limitations impede its application at laboratory scale: the equipment is expensive, there is a need of huge amounts of surfactants and co-surfactants during the preparation, and the operating conditions are energy intensive. Here, we present the microemulsion extrusion technique as an alternative method to prepare lipid nanoparticles. The parameters to produce lipid nanoparticles using microemulsion extrusion were established, and the lipid particles produced (SLN, NLC, and liposomes) were characterized with regard to size (from 130 to 190 nm), zeta potential, and drug (mitoxantrone) and gene (pDNA) delivery properties. In addition, the particles' in vitro co-delivery capacity (to carry mitoxantrone plus pDNA encoding the phosphatase and tensin homologue, PTEN) was tested in normal (BALB 3T3 fibroblast) and cancer (PC3 prostate and MCF-7 breast) cell lines. The results show that the microemulsion extrusion technique is fast, inexpensive, reproducible, free of organic solvents, and suitable for small volume preparations of lipid nanoparticles. Its application is particularly interesting when using rare and/or costly drugs or ingredients (e.g., cationic lipids for gene delivery or labeled lipids for nanoparticle tracking/diagnosis).
Gong, Xiaojuan; Moghaddam, Minoo J.; Sagnella, Sharon M.; Conn, Charlotte E.; Danon, Stephen J.; Waddington, Lynne J.; Drummond, Calum J.
An amphiphile prodrug, 5'-deoxy-5-fluoro-N4-(palmityloxycarbonyl) cytidine or 5'-deoxy-5-fluoro-N4-(hexadecanaloxycarbonyl) cytidine (5-FCPal), consisting of the same head group as the commercially available chemotherapeutic agent Capecitabine, linked to a palmityl hydrocarbon chain via a carbamate bond is reported. Thermal analysis of this prodrug indicates that it melts at ~115 °C followed quickly by degradation beginning at ~120 °C. The neat solid 5-FCPal amphiphile acquires a lamellar crystalline arrangement with a d-spacing of 28.6 ± 0.3 Å, indicating interdigitation of the hydrocarbon chains. Under aqueous conditions, solid 5-FCPal is non-swelling and no lyotropic liquid crystalline phase formation is observed. In order to assess the in vitro toxicity and in vivo efficacy in colloidal form, solid lipid nanoparticles (SLNs) with an average size of ~700 nm were produced via high pressure homogenization. The in vitro toxicity of the 5-FCPal SLNs against several different cancer and normal cell types was assessed over a 48 h period, and IC50 values were comparable to those observed for Capecitabine. The in vivo efficacy of the 5-FCPal SLNs was then assessed against the highly aggressive mouse 4T1 breast cancer model. To do so, the prodrug SLNs were administered orally at 3 different dosages (0.1, 0.25, 0.5 mmol/mouse/day) and compared to Capecitabine delivered at the same dosages. After 21 days of receiving the treatments, the 0.5 mmol dose of 5-FCPal exhibited the smallest average tumour volume. Since 5-FCPal is activated in a similar manner to Capecitabine via a 3 step enzymatic pathway with the final step occurring preferentially at the tumour site, formulation of the prodrug into SLNs combines the advantage of selective, localized activation with the sustained release properties of nanostructured amphiphile self-assembly and multiple payload materials thereby potentially creating a more effective anticancer agent.
Pawar, Harish; Surapaneni, Sunil Kumar; Tikoo, Kulbhushan; Singh, Charan; Burman, Rohani; Gill, Manjinder Singh; Suresh, Sarasija
The purpose of this study was to develop folic acid functionalized long-circulating co-encapsulated docetaxel (DTX) and curcumin (CRM) solid lipid nanoparticles (F-DC-SLN) to improve the pharmacokinetic and efficacy of DTX therapy. F-DC-SLN was prepared by hot melt-emulsification method and optimized by face centered-central composite design (FC-CCD). The SLN was characterized in terms of size and size distribution, drug entrapment efficiency and release profile. The cytotoxicity and cell uptake of the SLN formulations were evaluated in MCF-7 and MDA-MB-231 cell lines. The in vivo pharmacokinetic and biodistribution were studied in Wistar rats. F-DC-SLN exhibited 247.5 ± 3.40 nm particle size with 73.88 ± 1.08% entrapment efficiency and zeta potential of 14.53 ± 3.6 mV. Transmission electron microscopy (TEM) revealed spherical morphology of the SLN. Fluorescence microscopy confirmed the targeting efficacy of F-DC-SLN in MCF-7 cells. F-DC-SLN exhibited a significant increase in area under the curve (594.21 ± 64.34 versus 39.05 ± 7.41 μg/mL h) and mean residence time (31.14 ± 19.94 versus 7.24 ± 4.51 h) in comparison to Taxotere®. In addition, decreased DTX accumulation from F-DC-SLN in the heart and kidney in comparison to Taxotere may avoid to toxicity these vital organs. In conclusion, the F-DC-SLN improved the efficacy and pharmacokinetic profile of DTX exhibiting enhanced potential in optimizing breast cancer therapy.
Wang, Jiao; Wang, Haoyue; Zhu, Rongrong; Liu, Qiang; Fei, Jian; Wang, Shilong
Sepsis is a significant public healthcare problem, affecting millions of people worldwide each year, killing one in four, and increasing in incidence. Thus, advanced therapeutic strategies are required to treat sepsis patients. Curcumin (Cur) is a promising anti-inflammatory agent for various inflammatory disorders. However, the therapeutic efficacy of Cur is limited due to poor aqueous solubility, rapid degradation, and low bioavailability. The aims of this study were to evaluate the therapeutic potential of Cur-loaded solid lipid nanoparticles (Cur-SLNs) for sepsis treatment. A firefly luciferase transgenic mouse was used to monitor real time interleukin 1β (IL-1β) expression in lipopolysaccharide (LPS)-induced sepsis model to examine the protective effect of Cur-SLNs, and to elucidate its underlying molecular mechanisms. Mice (female or male) were intraperitoneally administered with free Cur or Cur-SLNs (30 mg/kg) before the intraperitoneal delivery of LPS (3 mg/kg). Our results indicated that Cur-SLNs can effectively reduced levels of IL-1β expression compared to free Cur, especially at 3 h after LPS injection. Also, Cur-SLNs significantly decreased the expression of serum pro-inflammatory cytokines, including IL-6, TNF-α, and IL-1β as compared with free Cur, but augmented anti-inflammatory cytokine IL-10 by ELISA assay. Further, marked alleviation of the sepsis-induced damage to organs, including kidney, liver, and heart was observed with Cur-SLNs treatment as determined by hematoxylin/eosin-staining. Western blot analyses revealed that Cur-SLNs can significantly lower the expression levels of TLR4, TLR2, and TNF-α in lymph node tissues. Meanwhile, it showed suppressions of NF-κB activation and IκBα degradation levels. In conclusion, we suggested that Cur-SLNs may be used as an effective and safe therapeutic agent in treating sepsis in high-risk patient groups.
Wang, Jiao; Zhu, Rongrong; Sun, Dongmei; Sun, Xiaoyu; Geng, Zhengsong; Liu, Hui; Wang, Shi-Long
Curcumin (Cur) is a naturally derived, novel anti-inflammatory agent, but its poor solubility limits its clinical use. The aim of the present study was to encapsulate Cur into solid lipid nanoparticles (SLNs) to improve its anti-inflammatory activity. The Cur-loaded SLNs (Cur-SLNs) were prepared using emulsification and low-temperature solidification methods. In contrast to free Cur, the particles were well dispersed in aqueous medium, showing a narrow size distribution with a range of 55 : 1.2 nm, a zeta potential value of -26.2 ± 1.3 mV, and a high drug loading efficiency of 37% ± 2.5%. The sustained release of Cur was observed for up to 6 days. The particles displayed enhanced stability in phosphate-buffered saline by protecting the encapsulated Cur against hydrolysis and biotransformation, as well as increasing biocompatibility. Cur-SLNs were more effective than free Cur at reducing the expression levels of several pro- inflammatory mediators, including inflammatory cytokines (IL-6, TNF-α, and IL-1β) and nitric oxide (NO), under in vitro conditions. By Western blotting, we found that Cur-SLNs were more active than free Cur in inhibiting the LPS-induced activation of the inflammatory transcription factor NF-κB through the suppression of IκB kinase activation. Compared to free Cur, Cur-SLNs had an increased intracellular uptake over time (observed after 24 h) in RAW264.7 cells. Moreover, the Cur-SLNs (≥ 20 μM) significantly improved RAW264.7 cell viability by inhibiting apoptosis. Thus, these results demonstrated that SLNs could be used as potential anti-inflammatory drug carriers for the treatment of various chronic diseases.
Severino, Patrícia; Chaud, Marco V; Shimojo, Andrea; Antonini, Danilo; Lancelloti, Marcelo; Santana, Maria Helena A; Souto, Eliana B
Polymyxins are a group of antibiotics with a common structure of a cyclic peptide with a long hydrophobic tail. Polymyxin B sulphate (PLX) has cationic charge, which is an obstacle for the efficient loading into Solid Lipid Nanoparticles (SLN). In the present paper, we describe an innovative method to load PLX into SLN to achieve the sustained release of the drug. PLX was firstly cross-linked with sodium alginate (SA) at different ratios (1:1, 1:2 and 1:3 SA/PLX), and loaded into SLN produced by high pressure homogenization (HPH). Optimized SLN were produced applying 500bar pressure and 5 homogenization cycles. The best results were obtained with SA/PLX (1:1), recording 99.08±1.2% for the association efficiency of the drug with SA, 0.99±10g for the loading capacity and 212.07±5.84% degree of swelling. The rheological profile of aqueous SA solution followed the typical behaviour of concentrated polymeric solutions, whereas aqueous SA/PLX solution exhibited a gel-like dynamic behaviour. Micrographs show that SA/PLX depicted a porous and discontinuous amorphous phase in different ratios. The encapsulation efficiency of SA/PLX (1:1) in SLN, the mean particle diameter, polydispersity index and zeta potential were, respectively, 82.7±5.5%; 439.5±20.42nm, 0.241±0.050 and -34.8±0.55mV. The effect of SLN on cell viability was checked in HaCat and NIH/3T3 cell lines, and the minimal inhibitory concentrations (MIC) were determined in Pseudomonas aeruginosa strains. SA/PLX-loaded SLN were shown to be less toxic than free PLX. Minimal inhibitory concentrations (MIC) showed the presence of the cross-linker polymer-drug complex, and SLN were shown to enhance MIC in the evaluated strains.
Shi, Li-Li; Cao, Yue; Zhu, Xiao-Yin; Cui, Jing-Hao; Cao, Qing-Ri
The aim of this study was to optimize the process variables of zanamivir-loaded solid lipid nanoparticles (SLNs) and to predict their cellular transport across Caco-2 cell monolayers. Zanamivir-loaded SLNs were prepared by a double emulsion solvent evaporation method. The effects of process variables on the mean particle size and zeta potential of SLNs were investigated and the physicochemical properties of SLNs were characterized. In addition, the cytotoxicity and transport ability of SLNs were also studied in Caco-2 cell model. The mean particle size of drug-loaded SLNs was significantly affected by the process variables. The SLNs were prepared using glyceryl monosterate (1% polyvinyl alcohol (PVA) or 1.5% poloxamer 188 as surfactant) had a regular shape with a relatively lower mean particle size (324.2 and 224.9 nm, respectively), higher encapsulation efficacy (55.7 and 42.4%, respectively) and sustained drug release over 12h. The crystalline form of drug had been partly changed and no physicochemical interaction had occurred between drug and carriers in SLNs. The cell viability was approximately 100% even at a high concentration of blank SLNs. There was no remarkable difference in drug permeation between drug-loaded SLNs and drug solution at 2h, while drug-loaded SLNs showed a significant decrease in drug permeation compared with the drug solution at 4h. The process variables of zanamivir-loaded SLNs were successfully optimized in this study. However, these SLNs significantly reduced the transport ability of zanamivir across Caco-2 cell monolayers. Further studies are needed to fully understand the real absorption mechanism of developed SLNs.
Patil, Hemlata; Feng, Xin; Ye, Xingyou; Majumdar, Soumyajit; Repka, Michael A
This contribution describes a continuous process for the production of solid lipid nanoparticles (SLN) as drug-carrier systems via hot-melt extrusion (HME). Presently, HME technology has not been used for the manufacturing of SLN. Generally, SLN are prepared as a batch process, which is time consuming and may result in variability of end-product quality attributes. In this study, using Quality by Design (QbD) principles, we were able to achieve continuous production of SLN by combining two processes: HME technology for melt-emulsification and high-pressure homogenization (HPH) for size reduction. Fenofibrate (FBT), a poorly water-soluble model drug, was incorporated into SLN using HME-HPH methods. The developed novel platform demonstrated better process control and size reduction compared to the conventional process of hot homogenization (batch process). Varying the process parameters enabled the production of SLN below 200 nm. The dissolution profile of the FBT SLN prepared by the novel HME-HPH method was faster than that of the crude FBT and a micronized marketed FBT formulation. At the end of a 5-h in vitro dissolution study, a SLN formulation released 92-93% of drug, whereas drug release was approximately 65 and 45% for the marketed micronized formulation and crude drug, respectively. Also, pharmacokinetic study results demonstrated a statistical increase in Cmax, Tmax, and AUC0-24 h in the rate of drug absorption from SLN formulations as compared to the crude drug and marketed micronized formulation. In summary, the present study demonstrated the potential use of hot-melt extrusion technology for continuous and large-scale production of SLN.
Thakkar, Arvind; Chenreddy, Sushma; Thio, Astrid; Khamas, Wael; Wang, Jeffrey; Prabhu, Sunil
Our previous studies have established the efficacy of chemopreventive regimens of aspirin and curcumin (CUR) encapsulated within solid lipid nanoparticles (SLNs) in combination with free sulforaphane (ACS combination) to prevent or delay the initiation and progression of pancreatic cancer, classified as one of the deadliest diseases with very low chances of survival upon diagnosis. Although toxicity of individual drugs and SLN has been studied previously, there are no studies in current literature that evaluate the potential toxicity of a combined regimen of ACS, especially when encapsulated within chitosan-SLNs (c-SLNs). Hence, objective of the current study was to investigate the potential toxic effects of ACS c-SLN combined chemopreventive regimens following acute (3 days), subacute (28 days), and subchronic (90 days) administrations by oral gavage in BALB/c mice. Mice were administered the following regimens: saline, blank c-SLN, low-dose ACS c-SLN (2+4.5+0.16 mg/kg), medium-dose ACS c-SLN (20+45+1.6 mg/kg), and high-dose ACS c-SLN (60+135+4.8 mg/kg). The potential toxicity was evaluated based on animal survival, body weight, hematology, blood chemistry, and organ histopathology. During 3-day, 28-day, and 90-day study periods, no animal deaths were observed. Treatment with ACS c-SLNs did not cause alteration in complete blood counts and blood chemistry data. Histopathological examination of various organ sections (pancreas, heart, liver, kidney, and brain) appeared normal. Based on the results of this study, no signs of toxicity in acute, subacute, and subchronic studies following oral administration of ACS c-SLNs were found indicating that the oral dosing regimens were safe at the levels tested for long-term administration to prevent the onset of pancreatic cancer. PMID:27499621
Wang, Fengzhen; Chen, Li; Zhang, Dongsheng; Jiang, Sunmin; Shi, Kun; Huang, Yuan; Li, Rui; Xu, Qunwei
The aims of this study were to design and characterize methazolamide (MTZ)-loaded solid lipid nanoparticles (SLN) with and without modification of low molecular weight chitosan (CS) and compare their potentials for ocular drug delivery. Low molecular weight CS was obtained via a modified chemical oxidative degradation method. SLN with CS (CS-SLN-MTZ) and without CS (SLN-MTZ) were prepared according to a modified emulsion-solvent evaporation method. SLN-MTZ and CS-SLN-MTZ were 199.4 ± 2.8 nm and 252.8 ± 4.0 nm in particle size, -21.3 ± 1.9 mV and +31.3 ± 1.7 mV in zeta potential, respectively. Physical stability studies demonstrated that CS-SLN-MTZ remained stable for at least 4 months at 4 °C, while SLN-MTZ no more than 2 months. A prolonged in vitro release profile of MTZ from CS-SLN-MTZ was obtained compared with SLN-MTZ. Furthermore, CS-SLN-MTZ presented a better permeation property in excised rabbit cornea. In vivo studies indicated that the intraocular pressure lowering effect of CS-SLN-MTZ (245.75 ± 18.31 mmHg × h) was significantly better than both SLN-MTZ (126.74 ± 17.73 mmHg × h) and commercial product Brinzolamide Eye Drops AZOPT® (171.17 ± 16.45 mmHg × h). The maximum percentage decrease in IOP of CS-SLN-MTZ (42.78 ± 7.71%) was higher than SLN-MTZ (27.82 ± 4.15%) and was comparable to AZOPT (38.06 ± 1.25%). CS-SLN-MTZ showed no sign of ocular irritancy according to the Draize method and the histological examination.
Huang, Rui; Yao, Xinyu; Chen, Yuan; Sun, Xun; Lin, Yunzhu
Multidrug resistance (MDR) remains the major obstacle to the success of clinical cancer chemotherapy. P-glycoprotein (P-gp), encoded by the MDR1, is an important part with complex mechanisms associated with the MDR. In order to overcome the MDR of tumors, we in the present experimental design incorporated small interfering RNA (siRNA) targeting MDR1 gene and anticancer drug paclitaxel (PTX) into the solid lipid nanoparticles (SLNs) to achieve the combinational therapeutic effects of genetherapy and chemotherapy. In this study, siRNA-PTX-SLNs were successfully prepared. The cytotoxicity of blank SLNs and siRNA-PTX-SLNs in MCF-7 cells and MCF-7/ADR cells were detected by MTT; and the uptake efficiency of PTX in MCF-7/ADR cells were detected via HPLC method; quantitative real-time PCR and flow cytometry were performed to investigate the silencing effect of siRNA-PTX- SLNs on MDR1 gene in MCF-7/ADR cells. The results showed that PTX loaded SLNs could significantly inhibit the growth of tumor cells, and more importantly, the MDR tumor cells treated with siRNA-PTX-SLNs showed the lowest viability. HPLC study showed that SLNs could enhance the cellular uptake for PTX. Meanwhile, siRNA delivered by SLNs significantly decreased the P-gp expression in MDR tumor cells, thus increased the cellular accumulation of rhodamine123 as a P-gp substrate. In conclusion, the MDR1 gene could be silenced by siRNA-PTX-SLNs, which could promote the growth inhibition efficiency of PTX on tumor cells, leading to synergetic effect on MDR tumor therapy.
Nafee, Noha; Husari, Ayman; Maurer, Christine K; Lu, Cenbin; de Rossi, Chiara; Steinbach, Anke; Hartmann, Rolf W; Lehr, Claus-Michael; Schneider, Marc
Cystic fibrosis (CF) is a genetic disease mainly manifested in the respiratory tract. Pseudomonas aeruginosa (P. aeruginosa) is the most common pathogen identified in cultures of the CF airways, however, its eradication with antibiotics remains challenging as it grows in biofilms that counterwork human immune response and dramatically decrease susceptibility to antibiotics. P. aeruginosa regulates pathogenicity via a cell-to-cell communication system known as quorum sensing (QS) involving the virulence factor (pyocyanin), thus representing an attractive target for coping with bacterial pathogenicity. The first in vivo potent QS inhibitor (QSI) was recently developed. Nevertheless, its lipophilic nature might hamper its penetration of non-cellular barriers such as mucus and bacterial biofilms, which limits its biomedical application. Successful anti-infective inhalation therapy necessitates proper design of a biodegradable nanocarrier allowing: 1) high loading and prolonged release, 2) mucus penetration, 3) effective pulmonary delivery, and 4) maintenance of the anti-virulence activity of the QSI. In this context, various pharmaceutical lipids were used to prepare ultra-small solid lipid nanoparticles (us-SLNs) by hot melt homogenization. Plain and QSI-loaded SLNs were characterized in terms of colloidal properties, drug loading, in vitro release and acute toxicity on Calu-3 cells. Mucus penetration was studied using a newly-developed confocal microscopy technique based on 3D-time-lapse imaging. For pulmonary application, nebulization efficiency of SLNs and lung deposition using next generation impactor (NGI) were performed. The anti-virulence efficacy was investigated by pyocyanin formation in P. aeruginosa cultures. Ultra-small SLNs (<100nm diameter) provided high encapsulation efficiency (68-95%) according to SLN composition, high burst in phosphate buffer saline compared to prolonged release of the payload over >8h in simulated lung fluid with minor burst. All
Sánchez-López, E; Espina, M; Doktorovova, S; Souto, E B; García, M L
In the recent decades, various controlled delivery systems have been introduced with the aim to improve solubility, stability and bioavailability of poorly absorbed drugs. Among all, lipid nanoparticles gather interesting properties as drug or gene delivery carriers. These systems, composed either of solid lipids (SLN) or of solid and liquid lipids (NLC) stabilized with surfactants, combine the advantages of other colloidal particles such as polymeric nanoparticles, fat emulsions and liposomes avoiding their main disadvantages. Lipid nanoparticles represent an interesting approach for eye drug delivery as they can improve the corneal absorption of drugs enhancing their bioavailability. The Generally Recognized as Safe status of formulation excipients, the scaling-up facilities and the possibility of sterilization, make them suitable for industrial production. In this review, the latest findings, potential applications, and challenges related to the use of lipid nanoparticles for ocular drug delivery are comprehensively discussed.
Nayak, Aditya P; Tiyaboonchai, Waree; Patankar, Swati; Madhusudhan, Basavaraj; Souto, Eliana B
In the present work, curcuminoids-loaded lipid nanoparticles for parenteral administration were successfully prepared by a nanoemulsion technique employing high-speed homogenizer and ultrasonic probe. For the production of nanoparticles, trimyristin, tristerin and glyceryl monostearate were selected as solid lipids and medium chain triglyceride (MCT) as liquid lipid. Scanning electron microscopy (SEM) revealed the spherical nature of the particles with sizes ranging between 120 and 250 nm measured by photon correlation spectroscopy (PCS). The zeta potential of the particles ranged between -28 and -45 mV depending on the nature of the lipid matrix produced, which also influenced the entrapment efficiency (EE) and drug loading capacity (LC) found to be in the range of 80-94% and 1.62-3.27%, respectively. The LC increased reciprocally on increasing the amount of MCT as confirmed by differential scanning calorimetry (DSC). DSC analyses revealed that increasing imperfections within the lipid matrix allowed for increasing encapsulation parameters. Nanoparticles were further sterilized by filtration process which was found to be superior over autoclaving in preventing thermal degradation of thermo-sensitive curcuminoids. The in vivo pharmacodynamic activity revealed 2-fold increase in antimalarial activity of curcuminoids entrapped in lipid nanoparticles when compared to free curcuminoids at the tested dosage level.
Mendes, M; Soares, H T; Arnaut, L G; Sousa, J J; Pais, A A C C; Vitorino, C
Lipid nanoparticles and their multiple designs have been considered appealing nanocarrier systems. Bringing the benefits of these nanosystems together with conventional coating technology clearly results in product differentiation. This work aimed at developing an innovative solid dosage form for oral administration based on tableting nanostructured lipid carriers (NLC), coated with conventional polymer agents. NLC dispersions co-encapsulating olanzapine and simvastatin (Combo-NLC) were produced by high pressure homogenization, and evaluated in terms of scalability, drying procedure, tableting and performance from in vitro release, cytotoxicity and intestinal permeability stand points. Factorial design indicated that the scaling-up of the NLC production is clearly feasible. Spray-drying was the method selected to obtain dry particles, not only because it consists of a single step procedure, but also because it facilitates the coating process of NLC with different polymers. Modified NLC formulations with the polymers allowed obtaining distinct release mechanisms, comprising immediate, delayed and prolonged release. Sureteric:Combo-NLC provided a low cytotoxicity profile, along with a ca. 12-fold OL/3-fold SV higher intestinal permeability, compared to those obtained with commercial tablets. Such findings can be ascribed to drug protection and control over release promoted by NLC, supporting them as a versatile platform able to be modified according to the intended needs.
Fang, Yi-Ping; Wu, Pao-Chu; Huang, Yaw-Bin; Tzeng, Cherng-Chyi; Chen, Yeh-Long; Hung, Yu-Han; Tsai, Ming-Jun; Tsai, Yi-Hung
Background The synthetic potential chemotherapeutic agent 3-Chloro-4-[(4-methoxyphenyl) amino]furo[2,3-b]quinoline (PK-L4) is an analog of amsacrine. The half-life of PK-L4 is longer than that of amsacrine; however, PK-L4 is difficult to dissolve in aqueous media, which is problematic for administration by intravenous injection. Aims To utilize solid lipid nanoparticles (SLNs) modified with polyethylene glycol (PEG) to improve the delivery of PK-L4 and investigate its biodistribution behavior after intravenous administration. Results The particle size of the PK-L4-loaded SLNs was 47.3 nm and the size of the PEGylated form was smaller, at 28 nm. The entrapment efficiency (EE%) of PK-L4 in SLNs with and without PEG showed a high capacity of approximately 100% encapsulation. Results also showed that the amount of PK-L4 released over a prolonged period from SLNs both with and without PEG was comparable to the non-formulated group, with 16.48% and 30.04%, respectively, of the drug being released, which fit a zero-order equation. The half-maximal inhibitory concentration values of PK-L4-loaded SLNs with and those without PEG were significantly reduced by 45%–64% in the human lung carcinoma cell line (A549), 99% in the human breast adenocarcinoma cell line with estrogen receptor (MCF7), and 95% in the human breast adenocarcinoma cell line (MDA-MB-231). The amount of PK-L4 released by SLNs with PEG was significantly higher than that from the PK-L4 solution (P < 0.05). After intravenous bolus of the PK-L4-loaded SLNs with PEG, there was a marked significant difference in half-life alpha (0.136 ± 0.046 hours) when compared with the PK-L4 solution (0.078 ± 0.023 hours); also the area under the curve from zero to infinity did not change in plasma when compared to the PK-L4 solution. This demonstrated that PK-L4-loaded SLNs were rapidly distributed from central areas to tissues and exhibited higher accumulation in specific organs. The highest deposition of PK-L4-loaded SLNs
Lu, Bin; Smith, Tyler; Schmidt, Jacob J.
The widespread environmental presence and commercial use of nanoparticles have raised significant health concerns as a result of many in vitro and in vivo assays indicating toxicity of a wide range of nanoparticle species. Many of these assays have identified the ability of nanoparticles to damage cell membranes. These interactions can be studied in detail using artificial lipid bilayers, which can provide insight into the nature of the particle-membrane interaction through variation of membrane and solution properties not possible with cell-based assays. However, the scope of these studies can be limited because of the low throughput characteristic of lipid bilayer platforms. We have recently described an easy to use, parallel lipid bilayer platform which we have used to electrically investigate the activity of 60 nm diameter amine and carboxyl modified polystyrene nanoparticles (NH2-NP and COOH-NP) with over 1000 lipid bilayers while varying lipid composition, bilayer charge, ionic strength, pH, voltage, serum, particle concentration, and particle charge. Our results confirm recent studies finding activity of NH2-NP but not COOH-NP. Detailed analysis shows that NH2-NP formed pores 0.3-2.3 nm in radius, dependent on bilayer and solution composition. These interactions appear to be electrostatic, as they are regulated by NH2-NP surface charge, solution ionic strength, and bilayer charge. The ability to rapidly measure a large number of nanoparticle and membrane parameters indicates strong potential of this bilayer array platform for additional nanoparticle bilayer studies.The widespread environmental presence and commercial use of nanoparticles have raised significant health concerns as a result of many in vitro and in vivo assays indicating toxicity of a wide range of nanoparticle species. Many of these assays have identified the ability of nanoparticles to damage cell membranes. These interactions can be studied in detail using artificial lipid bilayers, which
Cengiz, Mustafa; Kutlu, H Mehtap; Burukoglu, Dilek D; Ayhancı, Adnan
Nanostructure-mediated drug delivery is known to have a potential to improve drug bioavailability, apart from fostering release deviation of drug molecules and enabling precision drug targeting. Solid lipid nanoparticles (SLNs) have drawn great deal of the attention of scientists in finding a solution to minimize pharmaceutic limitations of the drugs used. Silymarin (Sm) has so far been used for treating diverse liver and gallbladder disorders, such as cirrhosis, hepatitis, and jaundice, and for protecting the liver against poisoning from chemical and environmental toxins on account of its antihepatotoxic and antioxidative properties. The present study aims to develop a novel silymarin-loaded solid lipid nanoparticle (Sm-loaded SLN) system with enhanced bioavailability and with an ability to provide excellent hepatic protection for poorly water-soluble drugs. Based upon our investigation results with apoptotic markers, PCNA and lightmicroscopic findings, it can be concluded that Sm-loaded SLN significantly reduced D-GaIN/TNF-α-induced hepatotoxicity, which suggested improved bioactivity compared to Sm. In conclusion, Sm-loaded SLN could be a useful system for the delivery of poorly water-soluble Sm, apart from providing favourable hepatic protection.
Charoenputtakun, Ponwanit; Li, S Kevin; Ngawhirunpat, Tanansait
The combined effects of iontophoresis and lipid nanoparticles on drug delivery across human epidermal membrane (HEM) were investigated. The delivery of lipophilic and hydrophilic drugs, all trans-retinoic acid (ATRA), salicylate (SA), and acyclovir (ACV), across HEM from lipid nanoparticles, solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC), was compared in passive and iontophoresis experiments in vitro. Iontophoresis experiments were also performed with synthetic Nuclepore membrane for comparison. Drug distribution in the skin after iontophoretic delivery with the lipid nanoparticles was examined using a model probe rhodamine B base (RhoB). The drug-loaded lipid nanoparticles had average sizes of ∼ 118-169 nm and a negative zeta potential. Iontophoresis did not enhance the delivery of ATRA across HEM from SLN and NLC. However, HEM distribution study of RhoB suggested that lipophilic drugs could be delivered into the deeper layer of the skin following iontophoretic delivery of the drugs from the lipid nanoparticles. Iontophoresis enhanced the delivery of hydrophilic drug SA with the lipid nanoparticles. Similarly, iontophoresis enhanced the delivery of ACV when it was loaded in SLN. These results suggest that lipid nanoparticles are a promising drug delivery method that can be combined with iontophoresis to improve skin delivery of hydrophilic drugs.
Cho, Nam-Joon (Inventor); Frank, Curtis W. (Inventor); Glenn, Jeffrey S. (Inventor); Cheong, Kwang Ho (Inventor)
The present invention provides a method of producing a planar lipid bilayer on a solid support. With this method, a solution of lipid vesicles is first deposited on the solid support. Next, the lipid vesicles are destabilized by adding an amphipathic peptide solution to the lipid vesicle solution. This destabilization leads to production of a planar lipid bilayer on the solid support. The present invention also provides a supported planar lipid bilayer, where the planar lipid bilayer is made of naturally occurring lipids and the solid support is made of unmodified gold or titanium oxide. Preferably, the supported planar lipid bilayer is continuous. The planar lipid bilayer may be made of any naturally occurring lipid or mixture of lipids, including, but not limited to phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidylinsitol, cardiolipin, cholesterol, and sphingomyelin.
Puri, Anu; Loomis, Kristin; Smith, Brandon; Lee, Jae-Ho; Yavlovich, Amichai; Heldman, Eli; Blumenthal, Robert
In recent years, various nanotechnology platforms in the area of medical biology, including both diagnostics and therapy, have gained remarkable attention. Moreover, research and development of engineered multifunctional nanoparticles as pharmaceutical drug carriers have spurred exponential growth in applications to medicine in the last decade. Design principles of these nanoparticles, including nano-emulsions, dendrimers, nano-gold, liposomes, drug-carrier conjugates, antibody-drug complexes, and magnetic nanoparticles, are primarily based on unique assemblies of synthetic, natural, or biological components, including but not limited to synthetic polymers, metal ions, oils, and lipids as their building blocks. However, the potential success of these particles in the clinic relies on consideration of important parameters such as nanoparticle fabrication strategies, their physical properties, drug loading efficiencies, drug release potential, and, most importantly, minimum toxicity of the carrier itself. Among these, lipid-based nanoparticles bear the advantage of being the least toxic for in vivo applications, and significant progress has been made in the area of DNA/RNA and drug delivery using lipid-based nanoassemblies. In this review, we will primarily focus on the recent advances and updates on lipid-based nanoparticles for their projected applications in drug delivery. We begin with a review of current activities in the field of liposomes (the so-called honorary nanoparticles), and challenging issues of targeting and triggering will be discussed in detail. We will further describe nanoparticles derived from a novel class of amphipathic lipids called bolaamphiphiles with unique lipid assembly features that have been recently examined as drug/DNA delivery vehicles. Finally, an overview of an emerging novel class of particles (based on lipid components other than phospholipids), solid lipid nanoparticles and nanostructured lipid carriers will be presented. We
Baowan, Duangkamon; Thamwattana, Ngamta
Lipid nanotubes are of particular interest for use as a template to create various one-dimensional nanostructures and as a carrier for drug and gene delivery. Understanding the encapsulation process is therefore crucial for such development. This paper models the interactions between lipid nanotubes and spheres of gold and silver nanoparticles and determines the critical dimension of lipid nanotubes that maximises the interaction with the nanoparticles. Our results confirm the acceptance of gold and silver nanoparticles inside lipid nanotubes. Further, we find that the lipid nanotube of radius approximately 10.23 nm is most favourable to encapsulate both types of nanoparticles.
Estella-Hermoso de Mendoza, A; Calvo, P; Bishop, A; Avilés, P; Blanco-Prieto, M J
PM02734 is a chemically synthesized depsipeptide derived from the marine kahalalides family with a broad spectrum of activity against solid tumors in vitro and in vivo, but presenting low bioavailability. In this work, solid lipid nanoparticles made of Precirol ATO 5 have been developed using a hot homogenization method followed by high shear homogenization and ultrasonication. These solid lipid nanoparticles show suitable size (around 150 nm) and encapsulation efficiency (nearly 70%) for the oral administration of the compound PM02734. A physical-chemical stability study was performed after 6 months of storage at different thermical conditions, concluding that solid lipid nanoparticles stored at 4 degrees C were more stable than solid lipid nanoparticles stored at 25 degrees C. The pharmacokinetic profile of drug-loaded solid lipid nanoparticles was also evaluated in Beagle dogs and compared with that of a cyclodextrin-based delivery system by means of AUC, C(max) and T(max) parameter estimation. Solid lipid nanoparticle based formulation provided a sustained release of the drug for a longer period of time than the cyclodextrins.
Maretti, Eleonora; Rustichelli, Cecilia; Romagnoli, Marcello; Balducci, Anna Giulia; Buttini, Francesca; Sacchetti, Francesca; Leo, Eliana; Iannuccelli, Valentina
For direct intramacrophagic antitubercular therapy, pulmonary administration through Dry Powder Inhaler (DPI) devices is a reasonable option. For the achievement of efficacious aerosolisation, rifampicin-loaded Solid Lipid Nanoparticle assemblies (SLNas) were developed using the melt emulsifying technique followed by freeze-drying. Indeed, this drying method can cause freezing or drying stresses compromising powder respirability. It is the aim of this research to offer novel information regarding pre-freezing variables. These included type and concentration of cryoprotectants, pre-freezing temperature, and nanoparticle concentration in the suspension. In particular, the effects of such variables were observed at two main levels. First of all, on SLNas characteristics - i.e., size, polydispersity index, zeta-potential, circularity, density, and drug loading. Secondly, on powder respirability, taking into account aerodynamic diameter, emitted dose, and respirable fraction. Considering the complexity of the factors involved in a successful respirable powder, a Design of Experiments (DoE) approach was adopted as a statistical tool for evaluating the effect of pre-freezing conditions. Interestingly, the most favourable impact on powder respirability was exerted by quick-freezing combined with a certain grade of sample dilution before the pre-freezing step without the use of cryoprotectants. In such conditions, a very high SLNas respirable fraction (>50%) was achieved, along with acceptable yields in the final dry powder as well as a reduction of powder mass to be introduced into DPI capsules with benefits in terms of administered drug dose feasibility.
Torrecilla, Josune; Del Pozo-Rodríguez, Ana; Solinís, María Ángeles; Apaolaza, Paola S; Berzal-Herranz, Beatriz; Romero-López, Cristina; Berzal-Herranz, Alfredo; Rodríguez-Gascón, Alicia
Gene silencing mediated by RNAi has gained increasing interest as an alternative for the treatment of infectious diseases such as refractory hepatitis C virus (HCV) infection. In this work we have designed and evaluated a non-viral vector based on solid lipid nanoparticles (SLN) bearing hyaluronic acid, protamine and a short hairpin RNA (shRNA74) targeted to the Internal Ribosome Entry Site (IRES) of the HCV. The vector was able to inhibit the expression of the HCV IRES in Huh-7 cells, with the inhibition level dependent on the shRNA74 to SLN ratio and on the shRNA74 dose added to the culture cells. The nanocarrier was also able to inhibit the replication in human hepatoma cells supporting a subgenomic HCV replicon (Huh-7 NS3-3'). The vector was quickly and efficiently internalized by the cells, and endocytosis was the most productive uptake mechanism for silencing. Clathrin-mediated endocytosis and to a lesser extent caveolae/lipid raft-mediated endocytosis were identified as endocytic mechanisms involved in the cell uptake. Internalization via the CD44 receptor was also involved, although this entry route seems to be less productive for silencing than endocytosis. The vector did not induce either hemolysis or agglutination of red cells in vitro, which was indicative of good biocompatibility. In summary, we have shown for the first time the ability of a non-viral SLN-based vector to silence a HCV replicon.
Akbaba, Hasan; Karagöz, Uğur; Selamet, Yusuf; Kantarcı, A. Gülten
The aim of this study was to develop a novel iron oxide nanoparticle synthesis method with in-situ surface coating. For this purpose multiple emulsions were used as microreactors for the first time and magnetic iron oxide particles synthesized in the core of cationic solid lipid nanoparticles. DLS, SEM, TEM, VSM, Raman Spectrometer, XRD, and XPS techniques were performed for characterization of the magnetic nanoparticles. Obtained magnetic nanoparticles are superparamagnetic and no additional process was needed for surface adjustments. They are positively charged as a result of cationic lipid coating and has appropriate particle size (<30 nm) for drug or nucleic acid delivery. Structure analysis showed that magnetic core material is in the form of magnetite. Saturation magnetization value was measured as 15-17 emu g-1 for lipid coated magnetic nanoparticles obtained by multiple emulsion method which is reasonably sufficient for magnetic targeting.
Neves, Ana Rute; Queiroz, Joana Fontes; Costa Lima, Sofia A; Figueiredo, Francisco; Fernandes, Rui; Reis, Salette
Oral administration is the preferred route for drug delivery and nanosystems represent a promising tool for protection and transport of hardly soluble, chemically unstable and poorly permeable drugs through the intestinal barrier. In the present work, we have studied lipid nanoparticles cellular uptake, internalization pathways and transcytosis routes through Caco-2 cell monolayers. Both lipid nanosystems presented similar size (∼180nm) and surface charge (-30mV). Nanostructured lipid carriers showed a higher cellular uptake and permeability across the barrier, but solid lipid nanoparticles could enter cells faster than the former. The internalization of lipid nanoparticles occurs mainly through a clathrin-mediated endocytosis mechanism, although caveolae-mediated endocytosis is also involved in the uptake. Both lipid nanoparticles were able to cross the intestinal barrier by a preferential transcellular route. This work contributed to a better knowledge of the developed nanosystems for the oral delivery of a wide spectrum of drugs.
Sangsen, Yaowaporn; Wiwattanawongsa, Kamonthip; Likhitwitayawuid, Kittisak; Sritularak, Boonchoo; Wiwattanapatapee, Ruedeekorn
The aim of this study was to develop and assess nanostructured lipid carriers (NLC) compared to solid lipid nanoparticles (SLN) for improving the oral bioavailability of oxyresveratrol (OXY). The OXY formulated as SLN (OXY-SLN) and NLC (OXY-NLC) were prepared by a high shear homogenization technique. The optimized OXY-NLC (NLC3) produced smaller nanoparticle sizes (96±0.9nm) than that of the OXY-SLN (108±0.3nm) with a homogeneous size distribution and a high zeta potential. The spherical NLC had a significantly higher efficiency for OXY entrapment (89±0.1%) and a better stability than the SLN after storage for 12 months at 4±2°C according to parameters such as smaller particles, greater zeta potential and a higher loading capacity (p<0.05). Differential scanning calorimetry (DSC) showed a less ordered crystalline structure of NLC than SLN. The accumulated drug in an amorphous state in the NLC was also confirmed by powder X-ray diffraction (PXRD). The in vitro release profiles of the OXY-NLC showed a more sustained release compared to the SLN and unformulated OXY. The in vivo pharmacokinetic profiles implied enterohepatic recycling of OXY in the Wistar rat. Meanwhile, the oral absorption pattern of OXY was modified by both types of lipid nanoparticles. The SLN and NLC increased the relative bioavailability of OXY to 125% and 177%, respectively, compared with unformulated OXY. These findings indicated that NLC could be used as a potential carrier to improve the oral bioavailability of OXY.
Potdar, Dipti; Sammalkorpi, Maria
Here, we use molecular dynamics simulations to characterize the heat transfer properties of lipid bilayer - gold nanoparticle systems in which the nanoparticle acts as a heat source. The focus is on dipalmitoylphosphatidylcholine (DPPC) lipid bilayers and thiolated alcohol and alkyl functionalized nanoparticles as prototype hydrophilic and hydrophobic nanoparticles. We find hydrophilic nanoparticles which are partly in contact with the surrounding water environment are more efficient in transferring heat to the system than hydrophobic ones which reside surrounded by the membrane. This is because of the hydrogen bonding capability of the hydroxy pentanethiol and the more efficient heat conductivity through water than the lipid bilayer. Additionally, we find the heat conductance is strongly asymmetric and has a discontinuity between the bilayer leaflets. In total, the findings provide understanding on heat transport from localized heat sources in lipid bilayers and could bear significance, e.g., in engineering and controlling photoactivated triggering of liposomal systems.
Leung, Alex K K; Tam, Yuen Yi C; Cullis, Pieter R
The discovery of RNA interference (RNAi) in mammalian cells has created a new class of therapeutics based on the reversible silencing of specific disease-causing genes. This therapeutic potential depends on the ability to deliver inducers of RNAi, such as short-interfering RNA (siRNA) and micro-RNA (miRNA), to cells of target tissues. This chapter reviews various challenges and delivery strategies for siRNA, with a particular focus on the development of lipid nanoparticle (LNP) delivery technologies. Currently, LNP delivery systems are the most advanced technology for systemic delivery of siRNA, with numerous formulations under various stages of clinical trials. We also discuss methods to improve gene silencing potency of LNP-siRNA, as well as application of LNP technologies beyond siRNA to the encapsulation of other nucleic acids such as mRNA and clustered regularly interspaced short palindromic repeats (CRISPR).
Martins, S; Silva, A C; Ferreira, D C; Souto, E B
Solid lipid nanoparticles (SLN) composed of trimyristin (solid lipid) and poloxamer 407 (surfactant) were prepared by a w/o/w emulsion technique for the incorporation of Salmon calcitonin, and further explored as protein carriers for oral delivery. Trimyristin SLN showed a mean size diameter of 200 nm with an association efficiency for calcitonin of approx. 86%. The morphology of SLN was investigated by cryo-SEM and by AFM, revealing spheroid shape SLN with a smooth surface. The in vitro release of calcitonin occurred for a period of 8 h, under both gastric and intestinal simulated pH conditions, predicting suitable properties for oral administration. The pharmacological activity of the protein was evaluated following oral dosage of calcitonin-loaded SLN in rats. SLN lowered the basal blood calcium levels by up to 20% with 500 IU/kg dose sustaining hypocalcaemia over 8 h. The results indicate that incorporation of Salmon calcitonin into trimyristin SLN is a key factor for the improvement of the efficiency of such carriers for oral delivery of proteins.
Winter, Evelyn; Dal Pizzol, Carine; Locatelli, Claudriana; Crezkynski-Pasa, Tânia Beatriz
Lipid nanoparticles have received considerable attention in the field of drug delivery, due their ability to incorporate lipophilic drugs and to allow controlled drug release. Solid lipid nanoparticles (SLN), nanostructured lipid carriers (NLC), and nanoemulsion (NE) are three different lipid nanostructured systems presenting intrinsically physical properties, which have been widely studied in recent years. Despite the extensive applicability of lipid nanoparticles, the toxicity of these systems has not been sufficiently investigated thus far. It is generally believed that lipids are biocompatible. However, it is known that materials structured in nanoscale might have their intrinsic physicochemical properties modified. Thus, the aim of this study was to evaluate the cytotoxicity of these three nanoparticle systems. To this end, in vitro and in vivo toxicity studies were carried out. Our results indicate that nanoparticles containing the solid lipid GMS (SLN and NLC) induced an important cytotoxicity in vitro, but showed minimal toxicity in vivo--evidenced by the body weight analysis. The NE did not induce in vitro toxicity and did not induce body weight alteration. On the contrary, the SLN and NLC possibly induce an inflammatory process in vivo. All nanoparticle systems induced lipid peroxidation in the animals' livers, but only SLN and NLC induced a decrease of antioxidant defences indicating that the main mechanism of toxicity is the induction of oxidative stress in liver. The higher toxicity induced by SLN and NLC indicates that the solid lipid GMS could be the responsible for this effect. Nevertheless, this study provides important insights for toxicological studies of different lipid nanoparticles systems.
Guney Eskiler, G; Cecener, G; Dikmen, G; Kani, I; Egeli, U; Tunca, B
Manganese (Mn)-based complexes have been drawing attention due to the fact that they are more effective than other metal complexes. However, the use of Mn(II)-based complexes in medicine remains limited because of certain side effects. The aim of this study was to investigate the cytotoxic and apoptotic effects of a novel Mn(II) complex [Mn2(μ-(C6H5)2CHCOO)2(bipy)4](bipy)(ClO4)2 and Mn(II) complex loaded solid lipid nanoparticles (SLNs) on MCF-7 and HUVEC control cells. The average diameter of Mn(II) complex was about 1120 ± 2.43 nm, while the average particle size of Mn(II) complex-SLNs was ∼340 ± 2.27 nm. The cytotoxic effects of Mn(II) complex and Mn(II)-SLNs were 86.8 and 66.4%, respectively (p < .05). Additionally, both Mn(II) complex (39.25%) and Mn(II)-SLNs (38.05%) induced apoptosis and increased the arrest of G0/G1 phase. However, Mn(II) complex exerted toxic effects on the HUVEC control cell (63.4%), whereas no toxic effects was observed when treated with Mn(II)-SLNs at 150 μM. As a consequence, SLNs might be potentially used for metal-based complexes in the treatment of cancer due to reducing size and toxic effects of metal-based complexes.
Wosicka-Frąckowiak, Hanna; Cal, Krzysztof; Stefanowska, Justyna; Główka, Eliza; Nowacka, Magdalena; Struck-Lewicka, Wiktoria; Govedarica, Biljana; Pasikowska, Monika; Dębowska, Renata; Jesionowski, Teofil; Srčič, Stane; Markuszewski, Michał Jan
Particulate drug carriers e.g. nanoparticles (NPs) have been shown to penetrate and accumulate preferentially in skin hair follicles creating high local concentration of a drug. In order to develop such a follicle targeting system we obtained and characterized solid lipid nanoparticles (SLN) loaded with roxithromycin (ROX). The mean particle size (172±2 nm), polydisperisty index (0.237±0.007), zeta potential (-31.68±3.10 mV) and incorporation efficiency (82.1±3.0%) were measured. The long term stability of ROX-loaded SLN suspensions was proved up to 26 weeks. In vitro drug release study was performed using apparatus 4 dialysis adapters. Skin irritation test conducted using the EpiDerm™ tissue model demonstrated no irritation potential for ROX-loaded SLN. Ex vivo human skin penetration studies, employing rhodamine B hexyl ester perchlorate (RBHE) as a fluorescent dye to label the particles, revealed fluorescence deep in the skin, specifically around the hair follicles up to over 1mm depth. The comparison of fluorescence intensities after application of RBHE solution and RBHE-labelled ROX-loaded SLN was done. Then cyanoacrylate follicular biopsies were obtained in vivo and analyzed for ROX content, proving the possibility of penetration to human pilosebaceous units and delivering ROX by using SLN with the size below 200 nm.
Niculae, G.; Lacatusu, I.; Badea, N.; Meghea, A.
The aim of the present study was to obtain efficient lipid nanoparticles loaded with butyl-methoxydibenzoylmethane (BMDBM) in order to develop cosmetic formulations with enhanced UVA blocking effect. For this purpose, two adequate liquid lipids (medium chain triglycerides and squalene) have been used in combination with two solid lipids (cetyl palmitate and glyceryl stearate) in order to create appropriate nanostructured carriers with a disordered lipid network able to accommodate up to 1.5% BMDBM. The lipid nanoparticles (LNs) were characterized in terms of particle size, zeta potential, entrapment efficiency, loading capacity and in vitro UVA blocking effect. The efficiency of lipid nanoparticles in developing some cosmetic formulations has been evaluated by determining the in vitro erythemal UVA protection factor. In order to quantify the photoprotective effect, some selected cream formulations based on BMDBM-LNs and a conventional emulsion were exposed to photochemical UV irradiation at a low energy to simulate the solar energy during the midday. The results obtained demonstrated the high ability of cream formulations based on BMDBM-LNs to absorb more than 96% of UVA radiation. Moreover, the developed cosmetic formulations manifest an enhanced UVA blocking effect, the erythemal UVA protection factor being four times higher than those specific to conventional emulsions.
In improving cancer chemotherapy, lipidic nanoparticle systems for drug delivery, such as liposomes and emulsions, have received much attention because they are capable of delivering their drug payload selectively to cancer cells and of circulating for a long period in the bloodstream. In addition, lipidic nanoparticles have been examined for use in gene delivery as a non-viral vector. Preparation methods of particles and drug loading methods are crucial for the physicochemical properties of nanoparticles, which are the key aspects for pharmaceutical applications. This review describes new preparation methods for nanoparticles and a loading method for drugs using nanotechnology, including an evaluation of nanoparticles from the point of drug release for applications in cancer therapy and gene delivery.
Milak, Spomenka; Medlicott, Natalie; Tucker, Ian G
Solid lipid microparticles were investigated as a taste-masking approach for a lipophilic weak base in a suspension. The idea was that the drug concentration in the aqueous phase of a suspension might be reduced by its partitioning into the solid lipid particles. Loratadine, as a model drug, was used to prepare Precirol ATO 5 microparticles by a Micromixer. The effects of three process variables: drug loading, PVA concentration and water/lipid ratio on the microparticle size, encapsulation efficiency, surface appearance, in-vitro release and drug partitioning in a suspension were studied. Loratadine release was slow in simulated saliva and very fast at the pH of stomach. In suspension of loratadine lipid microparticles, drug was released into the aqueous phase to the same concentration as in a drug suspension. Therefore, the usefulness of these microparticles for taste-masking in liquids is limited. However, they might be useful for taste-masking in solid dosage forms.
Liu, Chi-Hsien; Chiu, Hao-Che; Wu, Wei-Chi; Sahoo, Soubhagya Laxmi; Hsu, Ching-Yun
Topical delivery has the advantages including being user friendly and cost effective. Development of topical delivery carriers for lutein is becoming an important issue for the ocular drug delivery. Quantification of the partition coefficient of drug in the ocular tissue is the first step for the evaluation of delivery efficacy. The objectives of this study were to evaluate the effects of lipid nanoparticles and cyclodextrin (CD) on the corneal lutein accumulation and to measure the partition coefficients in the porcine cornea. Lipid nanoparticles combined with 2% HPβCD could enhance lutein accumulation up to 209.2 ± 18 (μg/g) which is 4.9-fold higher than that of the nanoparticles. CD combined nanoparticles have 68% of drug loading efficiency and lower cytotoxicity in the bovine cornea cells. From the confocal images, this improvement is due to the increased partitioning of lutein to the corneal epithelium by CD in the lipid nanoparticles. The novel lipid nanoparticles could not only improve the stability and entrapment efficacy of lutein but also enhance the lutein accumulation and partition in the cornea. Additionally the corneal accumulation of lutein was further enhanced by increasing the lutein payload in the vehicles. PMID:25101172
Noack, Andreas; Oidtmann, Johannes; Kutza, Johannes; Mäder, Karsten
Curcuminoid-loaded lipid nanoparticles were produced by melt homogenization. The used lipid matrices were medium chain triglycerides, trimyristin (TM), and tristearin. The mean particle size of the preparations was between 130 and 180 nm. The incorporated curcuminoids revealed a good stability over a period of 12 months. The curcuminoid-loaded lipid nanoparticles were intended for the oral delivery of curcuminoids. Therefore, the fate of the triglyceride matrix in simulated gastric and simulated intestinal media under the influence of pepsin and pancreatin, respectively, was assessed. The degradation of the triglycerides was monitored by the pH-stat method and with high performance thin layer chromatography in connection with spectrodensitometry to quantify the different lipid fractions. The TM nanoparticles were not degraded in simulated gastric fluid (SGF), but the decomposition of the triglyceride matrix was rapid in the intestinal media. The digestion process was faster in the simulated fed state medium compared to the simulated fasted state medium. Additionally, the stability of the incorporated drug was tested in the respective physiological media. The curcuminoids showed an overall good stability in the different test media. The release of the curcuminoids from the lipid nanoparticles was determined by fluorescence imaging techniques. A slow release of the drug was found in phosphate buffer. In contrast, a more distinct release of the curcuminoids was verifiable in SGF and in simulated intestinal fluids. Overall, it was considered that the transfer of the drug into the outer media was mainly triggered by the lipid degradation and not by drug release.
Kim, Edward Y.; Briley, Nicole E.; Tyndall, Erin R.; Xu, Jie; Li, Conggang; Ramamurthi, Kumaran S.; Flanagan, John M.; Tian, Fang
Many essential cellular processes including endocytosis and vesicle trafficking require alteration of membrane geometry. These changes are usually mediated by proteins that can sense and/or induce membrane curvature. Using spherical nanoparticle supported lipid bilayers (SSLBs), we characterize how SpoVM, a bacterial development factor, interacts with differently curved membranes by magic angle spinning solid-state NMR. Our results demonstrate that SSLBs are an effective system for structural and topological studies of membrane geometry-sensitive molecules. PMID:26488086
Swami, Rajan; Singh, Indu; Jeengar, Manish Kumar; Naidu, V G M; Khan, Wahid; Sistla, Ramakrishna
Delivering chemotherapeutics by nanoparticles into tumor is impeded majorly by two factors: nonspecific targeting and inefficient penetration. Targeted delivery of anti-cancer agents solely to tumor cells introduces a smart strategy because it enhances the therapeutic index compared with untargeted drugs. The present study was performed to investigate the efficiency of adenosine (ADN) to target solid lipid nanoparticles (SLN) to over expressing adenosine receptor cell lines such as human breast cancer and prostate cancer (MCF-7 and DU-145 cells), respectively. SLN were prepared by emulsification and solvent evaporation process using docetaxel (DTX) as drug and were characterized by various techniques like dynamic light scattering, differential scanning calorimeter and transmission electron microscopy. DTX loaded SLNs were surface modified with ADN, an adenosine receptors ligand using carbodiimide coupling. Conjugation was confirmed using infrared spectroscopy and quantified using phenol-sulfuric acid method. Conjugated SLN were shown to have sustained drug release as compared to unconjugated nanoparticles and drug suspension. Compared with free DTX and unconjugated SLN, ADN conjugated SLN showed significantly higher cytotoxicity of loaded DTX, as evidenced by in vitro cell experiments. The IC50 was 0.41 μg/ml for native DTX, 0.30 μg/ml for unconjugated SLN formulation, and 0.09 μg/ml for ADN conjugated SLN formulation in MCF-7 cell lines. Whereas, in DU-145, there was 2 fold change in IC50 of ADN-SLN as compared to DTX. IC50 was found to be 0.44 μg/ml for free DTX, 0.39 μg/ml for unconjugated SLN and 0.22 μg/ml for ADN-SLN. Annexin assay and cell cycle analysis assay further substantiated the cell cytotoxicity. Fluorescent cell uptake and competitive ligand-receptor binding assay corroborated the receptor mediated endocytosis pathway indicated role of adenosine receptors in internalization of conjugated particles. Pharmacokinetic studies of lipidic
Lacatusu, Ioana; Badea, Nicoleta; Murariu, Alina; Meghea, Aurelia
The efficiency of a cosmetic product depends not only on the active ingredients, but also on the carrier system devoted to improve its bioavailability. This article aims to encapsulate two couples of UV molecular absorbers, with a blocking action on both UV-A and UV-B domains, into efficient lipid nanoparticles. The effect of encapsulation on the specific properties such as sun protection factor and photostability behaviour has been demonstrated. The lipid nanoparticles with size range 30-350 nm and a polydispersity index between 0.217 and 0.244 are obtained using a modified high shear homogenisation method. The nanoparticles had spherical shapes with a single crystallisation form of lipid matrices characteristic for the least ordered crystal structure (α-form). The in vitro determination of photoprotection has led to high SPF ratings, with values of about 20, which assure a good photoprotection and filtering about 95% of UV radiation. The photoprotection effect after irradiation stage was observed to be increased more than twice compared to initial samples as a result of isomerisation phenomena. All the results have shown that good photoprotection effect and improved photostability could be obtained using such sunscreen couples, thus demonstrating that UV absorbers-solid lipid nanoparticles are promising carriers for cosmetic formulations.
The efficiency of a cosmetic product depends not only on the active ingredients, but also on the carrier system devoted to improve its bioavailability. This article aims to encapsulate two couples of UV molecular absorbers, with a blocking action on both UV-A and UV-B domains, into efficient lipid nanoparticles. The effect of encapsulation on the specific properties such as sun protection factor and photostability behaviour has been demonstrated. The lipid nanoparticles with size range 30-350 nm and a polydispersity index between 0.217 and 0.244 are obtained using a modified high shear homogenisation method. The nanoparticles had spherical shapes with a single crystallisation form of lipid matrices characteristic for the least ordered crystal structure (α-form). The in vitro determination of photoprotection has led to high SPF ratings, with values of about 20, which assure a good photoprotection and filtering about 95% of UV radiation. The photoprotection effect after irradiation stage was observed to be increased more than twice compared to initial samples as a result of isomerisation phenomena. All the results have shown that good photoprotection effect and improved photostability could be obtained using such sunscreen couples, thus demonstrating that UV absorbers-solid lipid nanoparticles are promising carriers for cosmetic formulations. PMID:21711592
Potter, Timothy M; Neun, Barry W; Stern, Stephan T
This chapter describes a method for the analysis of human hepatocarcinoma cells (HEP G2) for lipid peroxidation products, such as malondialdehyde (MDA), following treatment with nanoparticle formulations. Oxidative stress has been identified as a likely mechanism of nanoparticle toxicity, and cell-based in vitro systems for evaluation of nanoparticle-induced oxidative stress are widely considered to be an important component of biocompatibility screens. The products of lipid peroxidation, lipid hydroperoxides, and aldehydes, such as MDA, can be measured via a thiobarbituric acid reactive substances (TBARS) assay. In this assay, which can be performed in cell culture or in cell lysate, MDA combines with thiobarbituric acid (TBA) to form a fluorescent adduct that can be detected at an excitation wavelength of 530 nm and an emission wavelength of 550 nm. The results are then expressed as MDA equivalents, normalized to total cellular protein (determined by Bradford assay).
Wang, Jhi-Joung; Liu, Kuo-Sheng; Sung, K C; Tsai, Chia-Yin; Fang, Jia-You
Buprenorphine is a promising drug for the treatment of chronic pain and opioid dependence. The aim of the present work was to evaluate the feasibility of lipid nanoparticles with different oil/fatty ester ratios for injection of buprenorphine. To improve the release properties and analgesic duration of the drug, ester prodrugs were also incorporated into the nanoparticles for evaluation. Linseed oil and cetyl palmitate were respectively chosen as the liquid lipid and solid lipid in the inner phase of the nanoparticulate systems. Differential scanning calorimetry (DSC) was performed, and the particle size, zeta potential, molecular environment, and lipid/water partitioning were determined to characterize the state of the drug/prodrug and lipid modification. The in vitro release kinetics were measured by a Franz assembly. DSC showed that systems without oil (solid lipid nanoparticles, SLNs) had a more ordered crystalline lattice in the inner matrix compared to those with oil (nanostructured lipid carriers, NLCs and lipid emulsion, LE). The mean diameter of the nanoparticles ranged between 180 and 200nm. The in vitro drug/prodrug release occurred in a delayed manner in decreasing order as follows: SLN>NLC>LE. It was found that the release rate was reduced following an increase in alkyl ester chains in the prodrugs. The in vivo antinociception was examined by a cold ethanol tail-flick test in rats. Compared to an aqueous solution, a prolonged analgesic duration was detected after an intravenous injection of buprenorphine-loaded SLNs and buprenorphine propionate (Bu-C3)-loaded NLCs (with 10% linseed oil in the lipid phase). The Bu-C3 in NLCs even showed a maximum antinociceptive activity for 10h. In vitro erythrocyte hemolysis and lactate dehydrogenase (LDH) release from neutrophils demonstrated a negligible toxicity of these carriers. Our results indicate the feasibility of using lipid nanoparticles, especially SLNs and NLCs, as parenteral delivery systems for
Maier, Martin A; Jayaraman, Muthusamy; Matsuda, Shigeo; Liu, Ju; Barros, Scott; Querbes, William; Tam, Ying K; Ansell, Steven M; Kumar, Varun; Qin, June; Zhang, Xuemei; Wang, Qianfan; Panesar, Sue; Hutabarat, Renta; Carioto, Mary; Hettinger, Julia; Kandasamy, Pachamuthu; Butler, David; Rajeev, Kallanthottathil G; Pang, Bo; Charisse, Klaus; Fitzgerald, Kevin; Mui, Barbara L; Du, Xinyao; Cullis, Pieter; Madden, Thomas D; Hope, Michael J; Manoharan, Muthiah; Akinc, Akin
In recent years, RNA interference (RNAi) therapeutics, most notably with lipid nanoparticle-based delivery systems, have advanced into human clinical trials. The results from these early clinical trials suggest that lipid nanoparticles (LNPs), and the novel ionizable lipids that comprise them, will be important materials in this emerging field of medicine. A persistent theme in the use of materials for biomedical applications has been the incorporation of biodegradability as a means to improve biocompatibility and/or to facilitate elimination. Therefore, the aim of this work was to further advance the LNP platform through the development of novel, next-generation lipids that combine the excellent potency of the most advanced lipids currently available with biodegradable functionality. As a representative example of this novel class of biodegradable lipids, the lipid evaluated in this work displays rapid elimination from plasma and tissues, substantially improved tolerability in preclinical studies, while maintaining in vivo potency on par with that of the most advanced lipids currently available. PMID:23799535
Severino, Patrícia; Souto, Eliana B; Pinho, Samantha C; Santana, Maria H A
The aim of the present work was to load mitotane, an effective drug for adrenocortical carcinoma treatment, in solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC). The SLN and NLC were successfully prepared by high shear homogenization followed by hot high pressure homogenization. Formulations were composed of cetyl palmitate as the solid lipid for SLN, whereas for NLC PEGylated stearic acid was selected as solid lipid and medium chain triacylglycerols as the liquid lipid. Tween® 80 and Span® 85 were used as surfactants for all formulations. The particle size, zeta potential, polydispersity index (PI), encapsulation efficiency (EE), and loading capacity (LC) were evaluated. The SLN showed a mean particle size of 150 nm, PI of 0.20, and surface charge -10 mV, and the EE and LC could reach up to 92.26% and 0.92%, respectively. The NLC were obtained with a mean particle size of 250 nm, PI of 0.30, zeta potential -15 mV and 84.50% EE, and 0.84% LC, respectively. Hydrophilic coating of SLN with chitosan or benzalkonium chloride was effective in changing zeta potential from negative to positive values. The results suggest that mitotane was efficiently loaded in SLN and in NLC, being potential delivery systems for improving mitotane LC and controlled drug release.
Tosta, Fabiana Vaz; Andrade, Lígia Marquez; Mendes, Lívia Palmerston; Anjos, Jorge Luiz V.; Alonso, Antonio; Marreto, Ricardo Neves; Lima, Eliana Martins; Taveira, Stephânia Fleury
Paclitaxel (PAC) has shown potential for regulating hyperkeratosis in skin diseases and its encapsulation in lipid nanoparticles could improve topical treatments. So, solid lipid nanoparticles (SLN) and nanostructured lipid carriers with 12.5 % (NLC1) and 25 % (NLC2) oil content were obtained and characterized. Lipid dynamic behavior was investigated through electron paramagnetic resonance spectroscopy (EPR) and comparative evaluations of EPR, and stability and skin permeation studies were performed. High entrapment efficiency was obtained for all formulations (over 90 %). The absence (SLN) or addition of 12.5 % oil (NLC1) did not significantly alter nanoparticle mean diameter, but 25 % oil (NLC2) produced smaller particles (270.6 ± 13.5 nm). EPR studies showed that 12.5 % oil increased NLC1 fluidity at the surface. Surprisingly, more oil increased NLC2 superficial rigidity, due to the decrease in nanoparticle mean diameter and additional PAC accumulation in the superficial environment. The oil in lipid matrices improved the physicochemical stability of NLC formulations, and drug-oil chemical affinity prevented PAC expulsion during storage time. NLC2 improved PAC skin penetration and was the only formulation capable of enhancing PAC penetration to deeper skin layers (about 6.48 ± 1.39 µg/cm2). PAC-NLC2 seemed to be very promising nanocarriers for the topical delivery of PAC.
Gilbert, E; Roussel, L; Serre, C; Sandouk, R; Salmon, D; Kirilov, P; Haftek, M; Falson, F; Pirot, F
For the last years, the increase of the number of skin cancer cases led to a growing awareness of the need of skin protection against ultraviolet (UV) radiations. Chemical UV filters are widely used into sunscreen formulations as benzophenone-3 (BP-3), a usually used broad spectrum chemical UV filter that has been shown to exercise undesirable effects after topical application. Innovative sunscreen formulations are thus necessary to provide more safety to users. Lipid carriers seem to be a good alternative to formulate chemical UV filters reducing their skin penetration while maintaining good photo-protective abilities. The aim of this work was to compare percutaneous absorption and cutaneous bioavailability of BP-3 loaded into solid lipid nanoparticles (SLN), nanostructured lipid carriers (NLC), nanostructured polymeric lipid carriers (NPLC) and nanocapsules (NC). Particle size, zeta potential and in vitro sun protection factor (SPF) of nanoparticle suspensions were also investigated. Results showed that polymeric lipid carriers, comprising NPLC and NC, significantly reduced BP-3 skin permeation while exhibiting the highest SPF. This study confirms the interesting potential of NPLC and NC to formulate chemical UV filters.
Paulus, Michael; Degen, Patrick; Brenner, Thorsten; Tiemeyer, Sebastian; Struth, Bernd; Tolan, Metin; Rehage, Heinz
The formation of a layer of hydrophobic magnetite (Fe(3)O(4)) nanoparticles stabilized by lauric acid is analyzed by in situ X-ray reflectivity measurements. The data analysis shows that the nanoparticles partially disperse their hydrophobic coating. Consequently, a Langmuir layer was formed by lauric acid molecules that can be compressed into an untilted condensed phase. A majority of the nanoparticles are attached to the Langmuir film integrating lauric acid residue on their surface into the Langmuir film. Hence, the particles at the liquid-gas interface can be identified as so-called Janus beads, which are amphiphilic solids having two sides with different functionality.
Kreuzer, Martin; Trapp, Marcus; Dahint, Reiner; Steitz, Roland
In this paper, we study the interaction of charged polymers with solid-supported 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) membranes by in-situ neutron reflectivity. We observe an enormous swelling of the oligolamellar lipid bilayer stacks after incubation in solutions of poly(allylamine hydrochloride) (PAH) in D2O. The positively charged polyelectrolyte molecules interact with the lipid bilayers and induce a drastic increase in their d-spacing by a factor of ~4. Temperature, time, and pH influence the swollen interfacial lipid linings. From our study, we conclude that electrostatic interactions introduced by the adsorbed PAH are the main cause for the drastic swelling of the lipid coatings. The DMPC membrane stacks do not detach from their solid support at T > Tm. Steric interactions, also introduced by the PAH molecules, are held responsible for the stabilizing effect. We believe that this novel system offers great potential for fundamental studies of biomembrane properties, keeping the membrane’s natural fluidity and freedom, decoupled from a solid support at physiological conditions. PMID:26703746
Lee, Justin B; Zhang, Kaixin; Tam, Yuen Yi C; Quick, Joslyn; Tam, Ying K; Lin, Paulo JC; Chen, Sam; Liu, Yan; Nair, Jayaprakash K; Zlatev, Ivan; Rajeev, Kallanthottathil G; Manoharan, Muthiah; Rennie, Paul S; Cullis, Pieter R
The androgen receptor plays a critical role in the progression of prostate cancer. Here, we describe targeting the prostate-specific membrane antigen using a lipid nanoparticle formulation containing small interfering RNA designed to silence expression of the messenger RNA encoding the androgen receptor. Specifically, a Glu-urea-Lys PSMA-targeting ligand was incorporated into the lipid nanoparticle system formulated with a long alkyl chain polyethylene glycol-lipid to enhance accumulation at tumor sites and facilitate intracellular uptake into tumor cells following systemic administration. Through these features, and by using a structurally refined cationic lipid and an optimized small interfering RNA payload, a lipid nanoparticle system with improved potency and significant therapeutic potential against prostate cancer and potentially other solid tumors was developed. Decreases in serum prostate-specific antigen, tumor cellular proliferation, and androgen receptor levels were observed in a mouse xenograft model following intravenous injection. These results support the potential clinical utility of a prostate-specific membrane antigen–targeted lipid nanoparticle system to silence the androgen receptor in advanced prostate cancer. PMID:28131285
Teeranachaideekul, Veerawat; Souto, Eliana B; Müller, Rainer H; Junyaprasert, Varaporn B
The aim of this study was to characterize the physicochemical properties and to study in vitro release of ascorbyl palmitate from semi-solid lipid nanoparticles based on nanostructured lipid carriers (NLC gels) systems with the desired viscosity for dermal delivery. NLC gels were obtained by a one-step production procedure employing a high pressure homogenization technique using different solid lipid matrices. Ascorbyl palmitate (AP) was selected as a lipophilic active ingredient due to its range of cosmetic applications. After the production, particles within the size range 170-250 nm having polydispersity index lower than 0.3 were obtained from all formulations. After the AP incorporation into the NLC gels, the zeta potential increased to values higher than |30 mV|. Almost 100% encapsulation efficiency was observed. The obtained SEM and AFM data revealed non-spherical shaped nanoparticles. From DSC and X-ray diffraction studies, it was shown that the lipid recrystallized in the solid state possessing a less ordered structure as compared to the bulk material. The release study of active-loaded NLC gel formulations using Franz diffusion cells revealed that the type of lipid matrix affects both the rate and the release pattern. The viscoelastic measurements revealed a more elastic than viscous behaviour of NLC formulations indicating a typical gel-like structure.
McClements, David Julian
Food-grade nanoemulsions are being increasingly used in the food and beverage industry to encapsulate, protect, and deliver hydrophobic functional components, such as oil-soluble flavors, colors, preservatives, vitamins, and nutraceuticals. These nanoemulsions contain lipid nanoparticles (radius <100 nm) whose physicochemical characteristics (e.g., composition, dimensions, structure, charge, and physical state) can be controlled by selection of appropriate ingredients and fabrication techniques. Nanoemulsions have a number of potential advantages over conventional emulsions for applications within the food industry: higher stability to particle aggregation and gravitational separation; higher optical transparency; and, increased bioavailability of encapsulated components. On the other hand, there are also some risks associated with consumption of lipid nanoparticles that should be considered before they are widely utilized, such as their ability to alter the fate of bioactive components within the gastrointestinal tract and the potential toxicity of some of the components used in their fabrication (e.g., surfactants and organic solvents). This article provides an overview of the current status of the biological fate and potential toxicity of food-grade lipid nanoparticles suitable for utilization within the food and beverage industry.
Leonardi, Antonio; Bucolo, Claudio; Romano, Giovanni Luca; Platania, Chiara Bianca Maria; Drago, Filippo; Puglisi, Giovanni; Pignatello, Rosario
Addition of one or more surfactant agents is often necessary for the production of nanostructured lipid and polymeric systems. The removal of residual surfactants is a required step for technological and toxicological reasons, especially for peculiar applications, such as the ophthalmic field. This study was planned to assess the technological properties of some surfactants, commonly used for the production of lipid nanoparticles, as well as their ocular safety profile. Stable and small-size solid lipid nanoparticles were obtained using Dynasan(®) 114 as the lipid matrix and all the tested surfactants. However, from a toxicological point of view, the nanocarriers produced using Kolliphor(®) P188 were the most valuable, showing no irritant effect on the ocular surface up to the highest tested surfactant concentration (0.4%, w/v). The SLN produced using Cremophor(®) A25 and Lipoid(®) S100 were tolerated up to a surfactant concentration of 0.2% by weight, while for Tween(®) 80 and Kolliphor(®) HS 15 a maximum concentration of 0.05% can be considered totally not-irritant.
Sadeghi, Fatemeh; Ansari, Reza; Darvizeh, Mansour
This study is concerned with the oscillatory behavior of metallic nanoparticles, and in particular silver and gold nanoparticles, inside lipid nanotubes (LNTs) using the continuum approximation along with the 6-12 Lennard-Jones (LJ) potential function. The nanoparticle is modeled as a dense sphere and the LNT is assumed to be comprised of six layers including two head groups, two intermediate layers and two tail groups. To evaluate van der Waals (vdW) interactions, analytical expressions are first derived through undertaking surface and volume integrals which are then validated by a fully numerical scheme based on the differential quadrature (DQ) technique. Using the actual force distribution between the two interacting molecules, the equation of motion is directly solved utilizing the Runge-Kutta numerical integration scheme to arrive at the time history of displacement and velocity of the inner core. Also, a semi-analytical expression incorporating both geometrical parameters and initial conditions is introduced for the precise evaluation of oscillation frequency. A comprehensive study is conducted to gain an insight into the influences of nanoparticle radius, LNT length, head and tail group thicknesses and initial conditions on the oscillatory behavior of the metallic nanoparticles inside LNTs. It is found that the escape velocity and oscillation frequency of silver nanoparticles are higher than those of gold ones. It is further shown that the oscillation frequency is less affected by the tail group thickness when compared to the head group thickness.
Lazarovits, James; Chen, Yih Yang; Sykes, Edward A; Chan, Warren C W
Nanoparticles are suitable platforms for cancer targeting and diagnostic applications. Typically, less than 10% of all systemically administered nanoparticles accumulate in the tumour. Here we explore the interactions of blood components with nanoparticles and describe how these interactions influence solid tumour targeting. In the blood, serum proteins adsorb onto nanoparticles to form a protein corona in a manner dependent on nanoparticle physicochemical properties. These serum proteins can block nanoparticle tumour targeting ligands from binding to tumour cell receptors. Additionally, serum proteins can also encourage nanoparticle uptake by macrophages, which decreases nanoparticle availability in the blood and limits tumour accumulation. The formation of this protein corona will also increase the nanoparticle hydrodynamic size or induce aggregation, which makes nanoparticles too large to enter into the tumour through pores of the leaky vessels, and prevents their deep penetration into tumours for cell targeting. Recent studies have focused on developing new chemical strategies to reduce or eliminate serum protein adsorption, and rescue the targeting potential of nanoparticles to tumour cells. An in-depth and complete understanding of nanoparticle-blood interactions is key to designing nanoparticles with optimal physicochemical properties with high tumour accumulation. The purpose of this review article is to describe how the protein corona alters the targeting of nanoparticles to solid tumours and explains current solutions to solve this problem.
van Lehn, Reid; Alexander-Katz, Alfredo
A recent study has shown that a new class of synthetic ligand-protected gold nanoparticles is able to penetrate the cell membrane without inducing poration or endocytosis. Furthermore, these nanoparticles fuse with pure lipid bilayers while retaining high solubility in biological conditions. This complexation behavior is related to the morphology of the ligand shell, which is composed of alternating ribbon-like domains of linear alkanes with either hydrophobic or charged end-groups. Spontaneous complexation is surprising given the large free energy barrier for moving charges through the hydrophobic bilayer core. In this work, we provide a thermodynamic analysis of bilayer complexation supported by multiscale simulations. We show that the key to bilayer complexation is the rearrangement of ligands by bending to maximize hydrophobic matching and minimize charge exposure. We believe this result will improve our understanding of transmembrane proteins and enable the design of nanoparticles for drug delivery and biosensing applications.
Cavalcanti, Leide P.; Konovalov, Oleg; Torriani, Iris L.; Haas, Heinrich
Lipid-based cationic nanoparticles are a new promising option for tumor therapy, because they display enhanced binding and uptake at the neo-angiogenic endothelial cells, which a tumor needs for its nutrition and growth. By loading suitable cytotoxic compounds to the cationic carrier, the tumor endothelial and consequently also the tumor itself can be destroyed. For the development of such novel anti-tumor agents, the control of drug loading and drug release from the carrier matrix is essential. We have studied the incorporation of the hydrophobic anti-cancer agent Paclitaxel (PXL) into a variety of lipid matrices by X-Ray reflectivity measurements. Liposome suspensions from cationic and zwitterionic lipids, comprising different molar fractions of Paclitaxel, were deposited on planar glass substrates. After drying at controlled humidity, well ordered, oriented multilayer stacks were obtained, as proven by the presence of bilayer Bragg peaks to several orders in the reflectivity curves. The presence of the drug induced a decrease of the lipid bilayer spacing, and with an excess of drug, also Bragg peaks of drug crystals could be observed. From the results, insight into the solubility of Paclitaxel in the model membranes was obtained and a structural model of the organization of the drug in the membrane was derived. Results from subsequent pressure/area-isotherm and grazing incidence diffraction (GID) measurements performed with drug/lipid Langmuir monolayers were in accordance with these conjectures.
Wuttke, Stefan; Braig, Simone; Preiß, Tobias; Zimpel, Andreas; Sicklinger, Johannes; Bellomo, Claudia; Rädler, Joachim O; Vollmar, Angelika M; Bein, Thomas
We report the synthesis of MOF@lipid nanoparticles as a versatile and powerful novel class of nanocarriers based on metal-organic frameworks (MOFs). We show that the MOF@lipid system can effectively store dye molecules inside the porous scaffold of the MOF while the lipid bilayer prevents their premature release. Efficient uptake of the MOF@lipid nanoparticles by cancer cells makes these nanocarriers promising for drug delivery and diagnostic purposes.
Suares, Divya; Prabhakar, Bala
The present work aimed to develop and characterize sustained release cuboidal lipid polymeric nanoparticles (LPN) of rosuvastatin calcium (ROS) by solvent emulsification-evaporation process. A three factor, two level (2(3)) full-factorial design was applied to study the effect of independent variables, i.e. amount of lipid, surfactant and polymer on dependent variables, i.e. percent entrapment efficiency and particle size. Optimized formulations were further studied for zeta potential, TEM, in vitro drug release and ex vivo intestinal permeability. Cuboidal nanoparticles exhibited average particle size 61.37 ± 3.95 nm, entrapment efficiency 86.77 ± 1.27% and zeta potential -6.72 ± 3.25 mV. Nanoparticles were lyophilized to improve physical stability and obtain free-flowing powder. Effect of type and concentration of cryoprotectant required to lyophilize nanoparticles was optimized using freeze-thaw cycles. Mannitol as cryoprotectant in concentration of 5-8% w/v was found to be optimal providing zeta potential -20.4 ± 4.63 mV. Lyophilized nanoparticles were characterized using FTIR, DSC, XRD and SEM. Absence of C=C and C-F aromatic stretch at 1548 and 1197 cm(-1), respectively, in LPN indicated coating of drug by lipid and polymer. In vitro diffusion of ROS using dialysis bag showed pH-independent sustained release of ROS from LPN in comparison to drug suspension. Intestinal permeability by non-everted gut sac model showed prolonged release of ROS from LPN owing to adhesion of polymer to mucus layer. In vivo absorption of ROS from LPN resulted in 3.95-fold increase in AUC0-last and 7.87-fold increase in mean residence time compared to drug suspension. Furthermore modified tyloxapol-induced rat model demonstrated the potential of ROS-loaded LPN in reducing elevated lipid profile.
Cheng, Xinwei; Lee, Robert J
Lipid nanoparticles (LNPs) have shown promise as delivery vehicles for therapeutic oligonucleotides, including antisense oligos (ONs), siRNA, and microRNA mimics and inhibitors. In addition to a cationic lipid, LNPs are typically composed of helper lipids that contribute to their stability and delivery efficiency. Helper lipids with cone-shape geometry favoring the formation hexagonal II phase, such as dioleoylphosphatidylethanolamine (DOPE), can promote endosomal release of ONs. Meanwhile, cylindrical-shaped lipid phosphatidylcholine can provide greater bilayer stability, which is important for in vivo application of LNPs. Cholesterol is often included as a helper that improves intracellular delivery as well as LNP stability in vivo. Inclusion of a PEGylating lipid can enhance LNP colloidal stability in vitro and circulation time in vivo but may reduce uptake and inhibit endosomal release at the cellular level. This problem can be addressed by choosing reversible PEGylation in which the PEG moiety is gradually released in blood circulation. pH-sensitive anionic helper lipids, such as fatty acids and cholesteryl hemisuccinate (CHEMS), can trigger low-pH-induced changes in LNP surface charge and destabilization that can facilitate endosomal release of ONs. Generally speaking, there is no correlation between LNP activity in vitro and in vivo because of differences in factors limiting the efficiency of delivery. Designing LNPs requires the striking of a proper balance between the need for particle stability, long systemic circulation time, and the need for LNP destabilization inside the target cell to release the oligonucleotide cargo, which requires the proper selection of both the cationic and helper lipids. Customized design and empirical optimization is needed for specific applications.
Feng, Lan; Mumper, Russell J.
Nano-based delivery systems have attracted a great deal of attention in the past two decades as a strategy to overcome the low therapeutic index of conventional anticancer drugs and delivery barriers in solid tumors. Myriads of preclinical studies have been focused on developing nano-based formulations to effectively deliver taxanes, one of the most important and most prescribed anticancer drug types in the clinic. Given the hydrophobic property of taxanes, lipid-based NPs, serve as a viable alternative delivery system. This critical review will provide an overview and perspective of the advancement of lipid-based nanoparticles for taxane delivery. Currently available formulations of taxanes and their drawbacks as well as criteria for idea taxane delivery system will be discussed. PMID:22796606
Reitz, Claudia; Kleinebudde, Peter
The applicability of the solid lipid extrusion process as preparations method for sustained release dosage forms was investigated in this study. Two lipids with similar melting ranges but of different composition, glyceryl palmitostearate (Precirol ATO 5) and glyceryl trimyristate (Dynasan 114), and mixtures of each lipid with 50% or 75% theophylline were extruded at temperatures below their melting ranges. Extrudates were analyzed using differential scanning calorimetry, scanning electron microscopy, porosity measurements and in vitro drug dissolution studies. The possibility of processing lipids by softening instead of complete melting and without subsequent formation of low-melting, metastable polymorphs could be demonstrated. Extrudates based on formulations of glyceryl palmitostearate/theophylline (50:50) and glyceryl trimyristate/theophylline (50:50) showed sustained release properties. An influence of extrusion conditions on the matrix structure was shown for extrudates based on a mixture of glyceryl trimyristate and theophylline (50:50). Glyceryl trimyristate tended to solidify in porous structures after melting. Exceeding a material temperature of 50.5 degrees C led to porous extrudate matrices with a faster drug release. The production of novel, non porous sustained release matrices was possible at a material temperature of 49.5 degrees C. Extrudates based on glyceryl trimyristate/theophylline (50:50) only slight changes in melting enthalpy and stable drug release profiles.
Mhashal, Anil R.; Roy, Sudip
This paper deals with the effect of different size gold nanoparticles on the fluidity of lipid membrane at different regions of the bilayer. To investigate this, we have considered significantly large bilayer leaflets and incorporated only one nanoparticle each time, which was subjected to all atomistic molecular dynamics simulations. We have observed that, lipid molecules located near to the gold nanoparticle interact directly with it, which results in deformation of lipid structure and slower dynamics of lipid molecules. However, lipid molecules far away from the interaction site of the nanoparticle get perturbed, which gives rise to increase in local ordering of the lipid domains and decrease in fluidity. The bilayer thickness and area per head group in this region also get altered. Similar trend, but with different magnitude is also observed when different size nanoparticle interact with the bilayer. PMID:25469786
Puglia, Carmelo; Offerta, Alessia; Rizza, Luisa; Zingale, Giuseppe; Bonina, Francesco; Ronsisvalle, Simone
Lipid nanoparticles (LN) are drug carriers possessing advantages with respect to stability, drug release profile, and biocompatibility. There are several production methods for lipid nanoparticles. Recently high shear homogenization (HSH) and ultrasound (US) techniques have been used to produce these systems in a cheaper and easier way. The objective of the present study was to evaluate the effect of same important instrumental parameters, such as homogenization time (HT) and ultrasonication time (UT), on particle size (MD) and polydispersity index (PDI) of LNs obtained by HSH-US techniques. Curcumin was used as a model drug to be incapsulated in the LNs. LN were prepared by HSH-US technique using tripalmitin (Dynasan 116) and poloxamer 188 (Lutrol F68) as solid lipid and surfactant, respectively. The preparations were characterized and then evaluated using a factorial design study. From the results obtained, LNs produced by HSH-US method were characterized by nanodimension, high homogeneity and encapsulation efficiency. US technology plays an important role in controlling the final dimension of LN dispersion, while longer times of HSH seem mainly to exert a positive effect on the final homogeneity of particle dispersion. Additional studies are in progress to evaluate drug release profile from LNs, for further in vitro/in vivo correlation studies.
Dong, X; Mumper, R J
Fatty alcohols are commonly used in lipid-based drug delivery systems including parenteral emulsions and solid lipid nanoparticles (NPs). The purpose of these studies was to determine whether horse liver alcohol dehydrogenase (HLADH), a NAD-dependent enzyme, could metabolize the fatty alcohols within the NPs and thus serve as a mechanism to degrade these NPs in the body. Solid nanoparticles (<100 nm) were engineered from oil-in-water microemulsion precursors using emulsifying wax NF as the oil phase and polyoxyethylene 20-stearyl ether (Brij 78) as the surfactant. Emulsifying wax contains both cetyl and stearyl alcohols. NPs were incubated with the enzyme and NAD+ at 37 degrees C for up to 48 h, and the concentrations of fatty alcohols were quantitatively determined over time by gas chromatography (GC). The concentrations of cetyl alcohol and stearyl alcohol within the NPs decreased to only 10-20% remaining after 15-24 h of incubation. In parallel, NP size, turbidity and the fluorescence intensity of NADH all increased over time. It was concluded that horse liver alcohol dehydrogenase/NAD+ was able to metabolize the fatty alcohols within the NPs, suggesting that NPs made of fatty alcohols may be metabolized in the body via endogenous alcohol dehydrogenase enzyme systems.
Sznitowska, Malgorzata; Wolska, Eliza; Baranska, Helena; Cal, Krzysztof; Pietkiewicz, Justyna
Solid lipid microparticles (SLM) were produced by a two-step process that, firstly, involved the emulsification of the molten lipid phase in a heated aqueous phase and, secondly, the system cooling. Compritol 888 ATO and Precirol ATO 5, including their mixtures with Miglyol 812 or Witepsol H15 were used as lipid components (10-30% w/w). The average size of the SLM prepared with Compritol and Tween 80 as an emulsifier was 3-7μm and the influence of lipid concentration and thermal sterilization was not large. Dispersions of SLM with Precirol (10-20% w/w) gellified upon storage. SLM stabilized with another surfactant, Tego Care 450, were larger in size and measured 40μm on average. The use of the sonication step (5-15min) in hot formulations containing 5% w/w of Compritol resulted in the formation of the solid lipid nanoparticles (SLN) with average size 200-300nm. The smallest SLN size (below 100nm on average) was obtained in SLN that contained Tego Care and an antimicrobial agent Euxyl PE 9010; such combination evoked synergism between the surfactant and Euxyl components.
Liu, Juewen; Stace-Naughton, Alison; Jiang, Xingmao; Brinker, C. Jeffrey
Mixing liposomes with hydrophilic particles will induce fusion of the liposome onto the particle surface. Such supported bilayers have been extensively studied as a model for the cell membrane, while its application in drug delivery has not been pursued. In this communication, we report the use of phospholipids to achieve synergistic loading and encapsulating of a fluorescent dye (calcein) in mesoporous silica nanoparticles, and its delivery into mammalian cells. We found that cationic lipid DOTAP provides the highest calcein loading with the concentration inside silica ∼110× higher than that in the solution under experimental conditions. Compared to some other nanoparticle systems, protocells provide a simple construct for loading, sealing, delivering and releasing, and should serve as a useful system in nanomedicine. PMID:19173660
Fiedler, Steven L.; Violi, Angela
Abstract A metric of nanoparticle toxicity is the passive permeability rate through cellular membranes. To assess the influence of nanoparticle morphology on this process, the permeability of buckyball-sized molecules through a representative lipid bilayer was investigated by molecular-dynamics simulation. When C60 was compared with a prototypical opened C60 molecule and a representative combustion-generated particle, C68H29, the calculated free-energy profiles along the permeation coordinate revealed a sizable variation in form and depth. The orientation of the anisotropic molecules was determined by monitoring the principal axis corresponding to the largest moment of inertia, and free rotation was shown to be hindered in the bilayer interior. Diffusion constant values of the permeant molecules were calculated from a statistical average of seven to 10 trajectories at five locations along the permeation coordinate. A relatively minor variation of the values was observed in the bilayer interior; however, local resistance values spanned up to 24 orders of magnitude from the water layer to the bilayer center, due primarily to its exponential dependence on free energy. The permeability coefficient values calculated for the three similarly sized but structurally distinct nanoparticles showed a significant variance. The use of C60 to represent similarly sized carbonaceous nanoparticles for assessments of toxicity is questioned. PMID:20655842
Silva, N. J. O.; Saisho, S.; Mito, M.; Millán, A.; Palacio, F.; Cabot, A.; Iglesias, Ò.; Labarta, A.
We report a study on the pressure response of the anisotropy energy of hollow and solid maghemite nanoparticles. The differences between the maghemite samples are understood in terms of size, magnetic anisotropy and shape of the particles. In particular, the differences between hollow and solid samples are due to the different shape of the nanoparticles and by comparing both pressure responses it is possible to conclude that the shell has a larger pressure response when compared to the core.
Shenoy, Vikram S.; Gude, Rajiv P.; Murthy, Rayasa S. Ramachandra
The present study is aimed to investigate the formulation and in vitro anticancer activities of solid lipid nanoparticles (SLNs) of 5-fluorouracil (5-FU) prepared using glyceryl monostearate (GMS) and cetyl palmitate (CP) by hot homogenization method. The lipids were selected based on the partition coefficient of 5-FU in lipids. The lipid nanoparticles were optimized for process and formulation parameters. The optimized nanoparticles were characterized for their zeta potential, morphology, release kinetics, and anticancer activity. Higher entrapments were achieved using a combination of emulsifiers. The zeta potential of the optimized CP and GMS SLN formulation were -8.26 and -9.35 mV, respectively. Both the optimized formulations were spherical. The in vitro release studies of SLNs of both the lipid carriers followed Peppas-Korsenmeyer equation when carried out at pH 3.5 and 7.4. The chemosensitivity assay carried out in B16F10 cell lines revealed that CP SLNs had better cytotoxicity than 5-FU solution and GMS SLNs at 48 h of incubation. Subtoxic concentration of 5-FU-loaded CP SLNs (0.12 μg/mL) possessed comparable antimigrational activity, colony inhibition activity, and cytopathic as that of 5-FU solution effects. The results indicated that encapsulating 5-FU in CP would be a promising delivery system for delivering 5-FU.
Zhang, Lu; Feng, Qiang; Wang, Jiuling; Zhang, Shuai; Ding, Baoquan; Wei, Yujie; Dong, Mingdong; Ryu, Ji-Young; Yoon, Tae-Young; Shi, Xinghua; Sun, Jiashu; Jiang, Xingyu
The functionalized lipid shell of hybrid nanoparticles plays an important role for improving their biocompatibility and in vivo stability. Yet few efforts have been made to critically examine the shell structure of nanoparticles and its effect on cell-particle interaction. Here we develop a microfluidic chip allowing for the synthesis of structurally well-defined lipid-polymer nanoparticles of the same sizes, but covered with either lipid-monolayer-shell (MPs, monolayer nanoparticles) or lipid-bilayer-shell (BPs, bilayer nanoparticles). Atomic force microscope and atomistic simulations reveal that MPs have a lower flexibility than BPs, resulting in a more efficient cellular uptake and thus anticancer effect than BPs do. This flexibility-regulated cell-particle interaction may have important implications for designing drug nanocarriers.
Melby, Eric S.; Mensch, Arielle C.; Lohse, Samuel E.; Hu, Dehong; Orr, Galya; Murphy, Catherine J.; Hamers, Robert J.; Pedersen, Joel A.
The cell membrane represents an important biological interface that nanoparticles may encounter after being released into the environment. Interaction of nanoparticles with cellular membranes may alter membrane structure and function, lead to their uptake into cells, and elicit adverse biological responses. Supported lipid bilayers have proven to be valuable ex vivo models for biological membranes, allowing investigation of their mechanisms of interaction with nanoparticles with a degree of control impossible in living cells. To date, the majority of research on nanoparticle interaction with supported lipid bilayers has employed membranes composed of single or binary mixtures of phospholipids. Cellular membranes contain a wide variety of lipids and exhibit lateral organization. Ordered membrane domains enriched in specific membrane components are referred to as lipid rafts and have not been explored with respect to their interaction with nanoparticles. Here we develop model lipid raft-containing membranes amenable to investigation by a variety of surface-sensitive analytical techniques and demonstrate that lipid rafts influence the extent of nanoparticle attachment to model membranes. We determined conditions that allow reliable formation of bilayers containing rafts enriched in sphingomyelin and cholesterol and confirmed their morphology by structured illumination and atomic force microscopies. We demonstrate that lipid rafts increase attachment of cationic gold nanoparticles to model membranes under near physiological ionic strength conditions (0.1 M NaCl) at pH 7.4. We anticipate that these results will serve as the foundation for and motivate further study of nanoparticle interaction with compositionally varied lipid rafts.
Hu, Mingyang; Stanzione, Francesca; Sum, Amadeu K; Faller, Roland; Deserno, Markus
We propose the design for a nanoparticle carrier that combines three existing motifs into a single construct: a liposome is stabilized by anchoring it to an enclosed solid core via extended polymeric tethers that are chemically grafted to the core and physisorb into the surrounding lipid membrane. Such a design would exhibit several enticing properties, among them: (i) the anchoring stabilizes the liposome against a variety of external stresses, while preserving an aqueous compartment between core and membrane; (ii) the interplay of design parameters such as polymer length or grafting density enforces strong constraints on nanoparticle size and hence ensures a high degree of uniformity; and (iii) the physical and chemical characteristics of the individual constituents equip the construct with numerous functionalities that can be exploited in many ways. However, navigating the large parameter space requires a sound prior understanding for how various design features work together, and how this impacts potential pathways for synthesizing and assembling these nanoparticles. In this paper, we examine these connections in detail, using both soft matter theory and computer simulations at all levels of resolution. We thereby derive strong constraints on the experimentally relevant parameter space, and also propose potential equilibrium and nonequilibrium pathways for nanoparticle assembly.
Flurkey, William H.
Solid-phase extraction (SPE) was used to demonstrate how various lipids and lipid classes could be separated in a biochemistry laboratory setting. Three different SPE methods were chosen on their ability to separate a lipid mixture, consisting of a combination of a either a fatty acid, a triacylglycerol, a mono- or diacylglycerol, phospholipid,…
Eltayeb, Megdi; Stride, Eleanor; Edirisinghe, Mohan
A key challenge in the production of multicomponent nanoparticles for healthcare applications is obtaining reproducible monodisperse nanoparticles with the minimum number of preparation steps. This paper focus on the use of electrohydrodynamic (EHD) techniques to produce core-shell polymer-lipid structures with a narrow size distribution in a single step process. These nanoparticles are composed of a hydrophilic core for active component encapsulation and a lipid shell. It was found that core-shell nanoparticles with a tunable size range between 30 and 90 nm and a narrow size distribution could be reproducibly manufactured. The results indicate that the lipid component (stearic acid) stabilizes the nanoparticles against collapse and aggregation and improves entrapment of active components, in this case vanillin, ethylmaltol and maltol. The overall structure of the nanoparticles produced was examined by multiple methods, including transmission electron microscopy and differential scanning calorimetry, to confirm that they were of core-shell form.
Eltayeb, Megdi; Stride, Eleanor; Edirisinghe, Mohan
A key challenge in the production of multicomponent nanoparticles for healthcare applications is obtaining reproducible monodisperse nanoparticles with the minimum number of preparation steps. This paper focus on the use of electrohydrodynamic (EHD) techniques to produce core-shell polymer-lipid structures with a narrow size distribution in a single step process. These nanoparticles are composed of a hydrophilic core for active component encapsulation and a lipid shell. It was found that core-shell nanoparticles with a tunable size range between 30 and 90 nm and a narrow size distribution could be reproducibly manufactured. The results indicate that the lipid component (stearic acid) stabilizes the nanoparticles against collapse and aggregation and improves entrapment of active components, in this case vanillin, ethylmaltol and maltol. The overall structure of the nanoparticles produced was examined by multiple methods, including transmission electron microscopy and differential scanning calorimetry, to confirm that they were of core-shell form.
Wang, Jing-yi; Wang, Yu; Meng, Xia
In this study, cisplatin (CDDP)-loaded chitosan-coated solid lipid nanoparticles (SLN) was successfully formulated to treat HeLa cervical carcinoma. The formulation nanoparticles were nanosized and exhibited a controlled release of drug in physiological conditions. The blank nanoparticles exhibited an excellent biocompatibility profile indicating its suitability for cancer targeting. The incorporation of CDDP in SLN remarkably increased the cancer cell death as evident from the MTT assay. Importantly, CDDP-loaded chitosan-coated SLN (CChSLN) significantly ( P < 0.05) decreased the viability of cancer cells even at low concentration. The higher cytotoxicity potential of CChSLN was attributed to the higher cellular uptake as well as the sustained drug release manner in comparison with CSLN. Consistent with the cytotoxicity assay, CChSLN showed the lowest IC50 value of 0.6125 μg/ml while CSLN presented 1.156 μg/ml. CChSLN showed a significantly higher apoptosis in cancer cells compared to that of CSLN and CDDP, which is attributed to the better internalization of nanocarriers and controlled release of anticancer drugs in the intracellular environment. Our findings suggest that this new formulation could be a promising alternative for the treatment of cervical cancers. These findings are encouraging us to continue our research, with a more extended investigation of cellular response in real time and in animal models.
Arellano, Carlos Luis
Protein-based therapy is one of the most direct ways to manipulate cell function and treat human disease. Although protein therapeutics has made its way to clinical practice, with five of the top fifteen global pharmaceuticals being peptide or protein-based drugs, one common limitation is that the effects of protein therapy are only achieved through the targeting of cell surface receptors and intracellular domains. Due to the impermeability of the cell membrane to most foreign materials, entire classes of potentially therapeutic proteins cannot thoroughly be studied without a safe and efficient method of transporting proteins into the cytosol. We report the use of a combinatorially-designed bioreducible lipid-like material (termed "lipidoid") - based protein delivery platform for the transfection of human cancer cell lines. Lipidoid nanoparticles are synthesized through a thin film dispersion method. The degradation of the bioreducible nanoparticles was observed when exposed to glutathione, a highly reductive compound present in the cytosol. We demonstrate that the nanoparticles are capable of transfecting a dose-dependent concentration of our model protein, beta-galactosidase into HeLa cells. Furthermore, formulations of the lipidoid containing the cytotoxic proteins saporin and RNase-A are both capable of inhibiting tumor cell proliferation as observed in in vitro treatment of different human cancer cell lines. There was no observed loss in protein activity after lyophilization and long--term storage, indicating the potential of pre-clinical applications. Overall, we demonstrate an effective approach to protein formulation and intracellular delivery. We believe that our formulations will lead to the study of a whole class of previously untapped therapeutics that may generate new solutions for previously untreatable diseases.
B, Arun; D, Narendar; Veerabrahma, Kishan
The aim was to enhance the oral bioavailability of olmesartan medoxomil (OM) by preparing solid lipid nanoparticles (SLNs) and comparing with nanosuspension (OM-NS). OM-SLNs and OM-NS were prepared by known methods. Prepared SLNs were evaluated for physical characters and in vivo pharmacokinetic (PK) performance in rats. OM-NS showed more than four-fold increase in the solubility. During DSC and XRD studies, drug incorporated in SLNs was found to be in amorphous form. The relative bioavailability of OM-SLN and OM-NS was 7.21- and 3.52-fold when compared with that of coarse suspension. Further, OM-SLNs also increased the oral bioavailability by two-fold over that of OM-NS.
Raffin, Renata P; Lima, Amanda; Lorenzoni, Ricardo; Antonow, Michelli B; Turra, Cláudia; Alves, Marta P; Fagan, Solange B
Lipid nanoparticles are drug delivery systems able to increase bioavailability of poorly soluble drugs. They can be prepared with different lipid materials, especially natural lipids. Shea butter is a natural lipid obtained from the Butyrospermum parkii seed and rich in oleic and stearic acids. Nimesulide is a COX 2 selective anti-inflammatory that is poorly soluble in water. The purpose of this study was to develop and characterize shea butter lipid nanoparticles using a new technique and evaluate the in vivo activity of these nanoparticles. Lipid nanoparticles were prepared by melting shea butter and mixing with an aqueous phase using a high shear mixer. The nanoparticles presented pH of 6.9 +/- 0.1, mean particle size of 90 nm and a narrow polydispersity (0.21). Zeta potential was around -20 mV and the encapsulation efficiency was 97.5%. Drug release was evaluated using dialysis bags and presented monoexponential profile with t50% of 4.80 h (free drug t50% was only 2.86 h). Antinociceptive activity was performed by the acetic acid model. Both nimesulide and nimesulide-loaded nanoparticles presented significant activity compared to the control. The in vivo anti-inflammatory activity was evaluated by paw edema and was statistically different for the nanoparticles containing nimesulide compared to free nimesulide, blank nanoparticles and saline. In conclusion, the use of shea butter as encapsulating lipid was very successful and allowed nanoparticles to be prepared with a very simple technique. The nanoparticles presented significant pharmacological effects that were not seen for free drug administration.
Wilner, Samantha E.
Lipid nanoparticles (LNPs) provide an attractive option for therapeutic applications because they can self-assemble and carry a diverse set of cargoes ranging from hydrophobic drugs to small interfering RNA (siRNA). Liposomes and micelles represent two classes of LNPs that have been developed for medicinal purposes; however, active targeting of LNPs to specific tissues and LNP stability in vivo remain significant challenges. We have exploited the structural characteristics and targeting ability of nucleic acids to address these obstacles. Specifically, we have introduced short nucleic acid targeting species, called aptamers, to the surface of stable nucleic acid lipid particles (SNALPs), a subset of liposomes used in siRNA delivery. In this manner, we have actively targeted SNALPs to cancer cells that overexpress the transferrin receptor (TfR). HeLa cells expressing enhanced green fluorescent protein (EGFP) were treated with SNALPs bearing an antiTfR aptamer (C2) that was identified in our lab. C2-conjugated SNALPs showed increased levels of uptake by cells by flow cytometry. More importantly, the enhanced uptake by C2-conjugated SNALPs translated to an increased level of gene knockdown when SNALPs were loaded with anti-EGFP siRNA or anti-Lamin NC siRNA. Expression of EGFP and Lamin NC decreased, respectively. These preliminary studies illustrate that aptamer-conjugated SNALPs can be designed to knock down both endogenous and exogenous genes in cancer cells with high specificity. We have also used nucleic acids to stabilize lipid micelles by introducing short quadruplex forming oligonucleotide sequences at the lipid headgroup. Micelle formation was confirmed via dynamic light scattering, transmission electron microscopy, and small angle X-ray scattering. Micelle stability was assessed using NMR and by a FRET-based assay in the presence of serum proteins. Quadruplex-stabilized micelles demonstrated enhanced stability suggesting that alterations to oligonucleotide
High-density lipoprotein (HDL) nanoparticles doped with gadolinium lipids can be used as magnetic resonance imaging diagnostic agents for atherosclerosis. In this study, HDL nanoparticles with different molar fractions of gadolinium lipids (0 < xGd-lipids < 0.33) were prepared, and the MR relaxivity values (r1 and r2) for all compositions were measured. Both r1 and r2 parameters reached a maximal value at a molar fraction of approximately xGd-lipids = 0.2. Higher payloads of gadolinium did not significantly increase relaxivity values but induced changes in the structure of HDL, increasing the size of the particles from dH = 8.2 ± 1.6 to 51.7 ± 7.3 nm. High payloads of gadolinium lipids trigger conformational changes in HDL, with potential effects on the in vivo behavior of the nanoparticles. PMID:27713933
Hu, Yun; Ehrich, Marion; Fuhrman, Kristel; Zhang, Chenming
Due to the many beneficial properties combined from both poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) and liposomes, lipid-PLGA hybrid NPs have been intensively studied as cancer drug delivery systems, bio-imaging agent carriers, as well as antigen delivery vehicles. However, the impact of lipid composition on the performance of lipid-PLGA hybrid NPs as a delivery system has not been well investigated. In this study, the influence of lipid composition on the stability of the hybrid NPs and in vitro antigen release from NPs under different conditions was examined. The uptake of hybrid NPs with various surface charges by dendritic cells (DCs) was carefully studied. The results showed that PLGA NPs enveloped by a lipid shell with more positive surface charges could improve the stability of the hybrid NPs, enable better controlled release of antigens encapsulated in PLGA NPs, as well as enhance uptake of NPs by DC.
Song, Bo; Yuan, Huajun; Pham, Sydney V; Jameson, Cynthia J; Murad, Sohail
Nanoparticles are generally considered excellent candidates for targeted drug delivery. However, ion leakage and cytotoxicity induced by nanoparticle permeation is a potential problem in such drug delivery schemes because of the toxic effect of many ions. In this study, we have carried out a series of coarse-grained molecular dynamics simulations to investigate the water penetration, ion transport, and lipid molecule flip-flop in a protein-free phospholipid bilayer membrane during nanoparticle permeation. The effect of ion concentration gradient, pressure differential across the membrane, nanoparticle size, and permeation velocity have been examined in this work. Some conclusions from our studies include (1) The number of water molecules in the interior of the membrane during the nanoparticle permeation increases with the nanoparticle size and the pressure differential across the membrane but is unaffected by the nanoparticle permeation velocity or the ion concentration gradient. (2) Ion transport is sensitive to the size of nanoparticle as well as the ion concentration gradient between two sides of the membrane; no anion/cation selectivity is observed for small nanoparticle permeation, while anions are preferentially translocated through the membrane when the size of nanoparticle is large enough. (3) Incidences of lipid molecule flip-flop increases with the size of nanoparticle and ion concentration gradient and decreases with the pressure differential and the nanoparticle permeation velocity.
Brenner, Thorsten; Paulus, Michael; Schroer, Martin A; Tiemeyer, Sebastian; Sternemann, Christian; Möller, Johannes; Tolan, Metin; Degen, Patrick; Rehage, Heinz
The adsorption of differently charged nanoparticles at liquid-solid interfaces was investigated by in situ X-ray reflectivity measurements. The layer formation of positively charged maghemite (γ-Fe(2)O(3)) nanoparticles at the aqueous solution-SiO(2) interface was observed while negatively charged gold nanoparticles show no adsorption at this interface. Thus, the electrostatic interaction between the particles and the charged surface was determined as the driving force for the adsorption process. The data analysis shows that a logarithmic particle size distribution describes the density profile of the thin adsorbed maghemite layer. The size distribution in the nanoparticle solution determined by small angle X-ray scattering shows an average particle size which is similar to that found for the adsorbed film. The formed magehemite film exhibits a rather high stability.
Kandel, Prakash K.; Fernando, Lawrence P.; Ackroyd, P. Christine; Christensen, Kenneth A.
We report a simple and rapid method to prepare extremely bright, functionalized, stable, and biocompatible conjugated polymer nanoparticles incorporating functionalized polyethylene glycol (PEG) lipids by reprecipitation. These nanoparticles retain the fundamental spectroscopic properties of conjugated polymer nanoparticles prepared without PEG lipid, but demonstrate greater hydrophilicity and quantum yield compared to unmodified conjugated polymer nanoparticles. The sizes of these nanoparticles, as determined by TEM, were 21-26 nm. Notably, these nanoparticles were prepared with several PEG lipid functional end groups, including biotin and carboxy moieties that can be easily conjugated to biomolecules. We have demonstrated the availability of these end groups for functionalization using the interaction of biotin PEG lipid conjugated polymer nanoparticles with streptavidin. Biotinylated PEG lipid conjugated polymer nanoparticles bound streptavidin-linked magnetic beads, while carboxy and methoxy PEG lipid modified nanoparticles did not. Similarly, biotinylated PEG lipid conjugated polymer nanoparticles bound streptavidin-coated glass slides and could be visualized as diffraction-limited spots, while nanoparticles without PEG lipid or with non-biotin PEG lipid end groups were not bound. To demonstrate that nanoparticle functionalization could be used for targeted labelling of specific cellular proteins, biotinylated PEG lipid conjugated polymer nanoparticles were bound to biotinylated anti-CD16/32 antibodies on J774A.1 cell surface receptors, using streptavidin as a linker. This work represents the first demonstration of targeted delivery of conjugated polymer nanoparticles and demonstrates the utility of these new nanoparticles for fluorescence based imaging and sensing.We report a simple and rapid method to prepare extremely bright, functionalized, stable, and biocompatible conjugated polymer nanoparticles incorporating functionalized polyethylene glycol (PEG
Drašler, Barbara; Drobne, Damjana; Novak, Sara; Valant, Janez; Boljte, Sabina; Otrin, Lado; Rappolt, Michael; Sartori, Barbara; Iglič, Aleš; Kralj-Iglič, Veronika; Šuštar, Vid; Makovec, Darko; Gyergyek, Sašo; Hočevar, Matej; Godec, Matjaž; Zupanc, Jernej
Background The purpose of this work is to provide experimental evidence on the interactions of suspended nanoparticles with artificial or biological membranes and to assess the possibility of suspended nanoparticles interacting with the lipid component of biological membranes. Methods 1-Palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) lipid vesicles and human red blood cells were incubated in suspensions of magnetic bare cobalt ferrite (CoFe2O4) or citric acid (CA)-adsorbed CoFe2O4 nanoparticles dispersed in phosphate-buffered saline and glucose solution. The stability of POPC giant unilamellar vesicles after incubation in the tested nanoparticle suspensions was assessed by phase-contrast light microscopy and analyzed with computer-aided imaging. Structural changes in the POPC multilamellar vesicles were assessed by small angle X-ray scattering, and the shape transformation of red blood cells after incubation in tested suspensions of nanoparticles was observed using scanning electron microscopy and sedimentation, agglutination, and hemolysis assays. Results Artificial lipid membranes were disturbed more by CA-adsorbed CoFe2O4 nanoparticle suspensions than by bare CoFe2O4 nanoparticle suspensions. CA-adsorbed CoFe2O4-CA nanoparticles caused more significant shape transformation in red blood cells than bare CoFe2O4 nanoparticles. Conclusion Consistent with their smaller sized agglomerates, CA-adsorbed CoFe2O4 nanoparticles demonstrate more pronounced effects on artificial and biological membranes. Larger agglomerates of nanoparticles were confirmed to be reactive against lipid membranes and thus not acceptable for use with red blood cells. This finding is significant with respect to the efficient and safe application of nanoparticles as medicinal agents. PMID:24741305
Guo, Yachong; Terazzi, Emmanuel; Seemann, Ralf; Fleury, Jean Baptiste; Baulin, Vladimir A.
Hydrophobic nanoparticles introduced into living systems may lead to increased toxicity, can activate immune cells, or can be used as nanocarriers for drug or gene delivery. It is generally accepted that small hydrophobic nanoparticles are blocked by lipid bilayers and accumulate in the bilayer core, whereas big nanoparticles can only penetrate cells through slow energy-dependent processes, such as endocytosis, lasting minutes. In contrast to expectations, we demonstrate that lipid-covered hydrophobic nanoparticles may translocate through lipid membranes by direct penetration within milliseconds. We identified the threshold size for translocation: nanoparticles with diameters smaller than 5 nm stay trapped in the bilayer, whereas those with diameters larger than 5 nm insert into the bilayer, opening pores in the bilayer. The direct proof of this size-dependent translocation was provided by an in situ observation of a single event of a nanoparticle quitting the bilayer. This was achieved with a specially designed microfluidic device combining optical fluorescence microscopy with simultaneous electrophysiological measurements. A quantitative analysis of the kinetic pathway of a single nanoparticle translocation event demonstrated that the translocation is irreversible and that the nanoparticle can translocate only once. This newly discovered one-way translocation mechanism provides numerous opportunities for biotechnological applications, ranging from targeted biomaterial elimination and/or delivery to precise and controlled trapping of nanoparticles. PMID:27847863
Shangguan, Mingzhu; Qi, Jianping; Lu, Yi; Wu, Wei
Both solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) were artificially broken down into lipolysates. Their oral bioavailability, with silymarin as a model drug, was compared in dogs to highlight the contribution of their integral structure. The lipid nanoparticles were prepared using a conventional hot homogenization method, whereas the lipolysates were obtained through lipolysis in phospholipid- and bile salt-enriched simulated intestinal fluid. More than 80% of vehicle-associated drugs could be transformed into the water-soluble form of mixed micelles. Pharmacokinetics analysis in dogs showed a decrease in bioavailability of 74.86% and 59.09% for lipolysates compared to integral NLCs and SLNs, respectively. It was indicated that lipolysates contributed to a majority of drug absorption. Integral nanoparticles were superior to their lipolysate counterparts, but only marginally; if the approximately 20% of the drug that precipitated during in vitro lipolysis was deducted from the overall absorption amount, the superiority of integral nanoparticles would be significantly compromised. In conclusion, lipolysis was the predominant in vivo absorption mechanism, and the contribution of intact lipid nanoparticles was limited.
Islan, Germán A; Tornello, Pablo Cortez; Abraham, Gustavo A; Duran, Nelson; Castro, Guillermo R
Levofloxacin (LV) is a hydrophilic broad-spectrum antibiotic commonly used in pulmonary treatment against recurrent infections of Pseudomonas aeruginosa, and particularly in cystic fibrosis (CF) disease. In order to study feasible carriers for LV, solid lipid nanoparticles (SLN) of myristyl myristate were prepared by the ultrasonication method in the presence of Pluronic(®)F68 under different experimental conditions and characterized by dynamic light scattering, optical, transmission and scanning electron microscopy for size and morphology. Alternatively, nanostructured lipid carriers (NLCs) were developed to improve LV encapsulation and storage. SLN showed 20.1±1.4% LV encapsulation efficiency, while the NLCs encapsulated 55.9±1.6% LV. NLC formulation exhibited a more controlled release profile than SLN formulation, but both showed a biphasic drug release pattern with burst release at the first 5h and prolonged release afterwards, demonstrated by in vitro tests. The hydrodynamic average diameter and zeta potential of NLC were 182.6±3.2nm and -10.2±0.2mV, respectively, and were stable for at least 3 months. Additionally, DNase type I was incorporated into the formulations as a "smart" component, since the enzyme could help to decrease the viscoelasticity found in the lungs of CF patients and improves the antibiotic diffusion. FTIR, XRD, DSC, TGA and nitrogen adsorption isotherms of the nanoparticles indicate the presence of the loads in a noncrystalline state. The developed formulation showed an active antimicrobial activity against P. aeruginosa and even against other opportunistic pathogens such as Staphylococcus aureus. The presence of LV-loaded NLCs reduced the formation of a bacterial biofilm, which highlighted the significance of the nanodevice as a new alternative for CF treatment.
Gonçalves, V S S; Matias, A A; Rodríguez-Rojo, S; Nogueira, I D; Duarte, C M M
Structured lipid carriers based on mixture of solid lipids with liquid lipids are the second generation of solid lipid particles, offering the advantage of improved drug loading capacity and higher storage stability. In this study, structured lipid carriers were successfully prepared for the first time by precipitation from gas saturated solutions. Glyceryl monooleate (GMO), a liquid glycerolipid, was selected in this work to be incorporated into three solid glycerolipids with hydrophilic-lipophilic balance (HLB) ranging from 1 to 13, namely Gelucire 43/01™, Geleol™ and Gelucire 50/13™. In general, microparticles with a irregular porous morphology and a wide particle size distribution were obtained. The HLB of the individual glycerolipids might be a relevant parameter to take into account during the processing of solid:liquid lipid blends. As expected, the addition of a liquid lipid into a solid lipid matrix led to increased stability of the lipid carriers, with no significant modifications in their melting enthalpy after 6 months of storage. Additionally, Gelucire 43/01™:GMO particles were produced with different mass ratios and loaded with ketoprofen. The drug loading capacity of the structured lipid carriers increased as the GMO content in the particles increased, achieving a maximum encapsulation efficiency of 97% for the 3:1 mass ratio. Moreover, structured lipid carriers presented an immediate release of ketoprofen from its matrix with higher permeation through a mucous-membrane model, while solid lipid particles present a controlled release of the drug with less permeation capacity.
Xiao, Xiaoyin; Montaño, Gabriel A; Edwards, Thayne L; Allen, Amy; Achyuthan, Komandoor E; Polsky, Ronen; Wheeler, David R; Brozik, Susan M
Electrostatic interaction plays a leading role in nanoparticle interactions with membrane architectures and can lead to effects such as nanoparticle binding and membrane disruption. In this work, the effects of nanoparticles (NPs) interacting with mixed lipid systems were investigated, indicating an ability to tune both NP binding to membranes and membrane disruption. Lipid membrane assemblies (LBAs) were created using a combination of charged, neutral, and gel-phase lipids. Depending on the lipid composition, nanostructured networks could be observed using in situ atomic force microscopy representing an asymmetrical distribution of lipids that rendered varying effects on NP interaction and membrane disruption that were domain-specific. LBA charge could be localized to fluidic domains that were selectively disrupted when interacting with negatively charged Au nanoparticles or quantum dots. Disruption was observed to be related to the charge density of the membrane, with a maximum amount of disruption occurring at ∼40% positively charged lipid membrane concentration. Conversely, particle deposition was determined to begin at charged lipid concentrations greater than 40% and increased with charge density. The results demonstrate that the modulation of NP and membrane charge distribution can play a pivitol role in determining NP-induced membrane disruption and NP surface assembly.
Yang, Yue; Cheow, Wean Sin; Hadinoto, Kunn
Lipid-polymer hybrid nanoparticles have emerged as promising nanoscale carriers of therapeutics as they combine the attractive characteristics of liposomes and polymers. Herein we develop dry powder inhaler (DPI) formulation of hybrid nanoparticles composed of poly(lactic-co-glycolic acid) and soybean lecithin as the polymer and lipid constituents, respectively. The hybrid nanoparticles are transformed into inhalable microscale nanocomposite structures by a novel technique based on electrostatically-driven adsorption of nanoparticles onto polysaccharide carrier particles, which eliminates the drawbacks of conventional techniques based on controlled drying (e.g. nanoparticle-specific formulation, low yield). First, we engineer polysaccharide carrier particles made up of chitosan cross-linked with tripolyphosphate and dextran sulphate to exhibit the desired aerosolization characteristics and physical robustness. Second, we investigate the effects of nanoparticle to carrier mass ratio and salt inclusion on the adsorption efficiency, in terms of the nanoparticle loading and yield, from which the optimal formulation is determined. Desorption of the nanoparticles from the carrier particles in phosphate buffer saline is also examined. Lastly, we characterize aerosolization efficiency of the nanocomposite product in vitro, where the emitted dose and respirable fraction are found to be comparable to the values of conventional DPI formulations.
Tan, Shengwei; Wang, Lei; Liu, Hang; Wu, Hongwen; Liu, Quanjun
The nanopore sensor as a high-throughput and low-cost technology can detect single nanoparticle in solution. In the present study, the silicon nitride nanopores were fabricated by focused Ga ion beam (FIB), and the surface was functionalized with 3-aminopropyltriethoxysilane to change its surface charge density. The positively charged nanopore surface attracted negatively charged nanoparticles when they were in the vicinity of the nanopore. And, nanoparticle translocation speed was slowed down to obtain a clear and deterministic signal. Compared with previous studied small nanoparticles, the electrophoretic translocation of negatively charged polystyrene (PS) nanoparticles (diameter ~100 nm) was investigated in solution using the Coulter counter principle in which the time-dependent nanopore current was recorded as the nanoparticles were driven across the nanopore. A linear dependence was found between current drop and biased voltage. An exponentially decaying function ( t d ~ e -v/v0 ) was found between the duration time and biased voltage. The interaction between the amine-functionalized nanopore wall and PS microspheres was discussed while translating PS microspheres. We explored also translocations of PS microspheres through amine-functionalized solid-state nanopores by varying the solution pH (5.4, 7.0, and 10.0) with 0.02 M potassium chloride (KCl). Surface functionalization showed to provide a useful step to fine-tune the surface property, which can selectively transport molecules or particles. This approach is likely to be applied to gene sequencing.
Huber, Lucas A; Pereira, Tatiana A; Ramos, Danielle N; Rezende, Lucas C D; Emery, Flávio S; Sobral, Lays Martin; Leopoldino, Andréia Machado; Lopez, Renata F V
The topical administration of chemotherapeutics is a promising approach for the treatment of skin cancer; however, different pharmaceutical strategies are required to allow large amounts of drug to penetrate tumors. This work examined the potential of the anodic iontophoresis of doxorubicin-loaded cationic solid lipid nanoparticles (DOX-SLN) to increase the distribution and tumor penetration of DOX. A double-labeled cationic DOX-SLN composed of the lipids stearic acid and monoolein and a new BODIPY dye was prepared and characterized. The skin distribution and penetration of DOX were evaluated in vitro using confocal microscopy and vertical diffusion cells, respectively. The antitumor potential was evaluated in vivo through the anodic iontophoresis of DOX-SLN in squamous cell carcinoma induced in nude BALB/c mice. The encapsulation of DOX drastically altered the DOX partition coefficient and increased the distribution of DOX in the lipid matrix of the stratum corneum (SC). The association with iontophoresis created high-concentration drug reservoir zones in the follicles of the skin. Although the iontophoresis of a DOX solution increased the penetration of DOX in the viable epidermis by approximately 4-fold, the iontophoresis of cationic DOX-SLN increased the DOX penetration by approximately 50-fold. In vivo, the DOX-SLN iontophoretic treatment was effective in inhibiting tumor cell survival and tumor growth and was accompanied by an increase in keratinization and consequent cell death. These results indicate a strong and synergic effect of iontophoresis with DOX-SLN and provide a potential strategy for the treatment of skin cancer.
Sharma, Hari; Wang, Zilu; Dormidontova, Elena
There is a growing interest in applications of nanoparticles in biomedicine. For practical applications of gold nanoparticles it is often desirable to encapsulate them into lipid nanocarriers. To this end it is important to understand gold-lipid interactions at the molecular level. We have performed coarse grained molecular dynamics simulations using a MARTINI force field of a lipid nanodisk composed of long and short tail lipids, DPPC and DHPC mixed in the ratio of 3:1 and studied its interaction with small gold nanoparticles (AuNP) functionalized with hydrophobic alkane tethers. We found that the inhomogeneous distribution of lipids in the nanodisk affects the outcome the AuNP-nanodisk interaction. The ordered arrangement of long chain lipids forming the interior region of the nanodisk are found to be less accessible for AuNP penetration compared to the rim of the nanodisk, where more mobile short lipids are located. Once encapsulated into a nanodisk, AuNP's have tendency to aggregate, especially if temperature is not too low. The results of computer modeling will be compared to experiment and the implications of our findings for experimental design of lipid nanocarriers for AuNP delivery will be discussed.
Rose, Fabrice; Wern, Jeanette Erbo; Ingvarsson, Pall Thor; van de Weert, Marco; Andersen, Peter; Follmann, Frank; Foged, Camilla
The purpose of this study was to design a novel and versatile adjuvant intended for mucosal vaccination based on biodegradable poly(DL-lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) modified with the cationic surfactant dimethyldioctadecylammonium (DDA) bromide and the immunopotentiator trehalose-6,6'-dibehenate (TDB) (CAF01) to tailor humoral and cellular immunity characterized by antibodies and Th1/Th17 responses. Such responses are important for the protection against diseases caused by intracellular bacteria such as Chlamydia trachomatis and Mycobacterium tuberculosis. The hybrid NPs were engineered using an oil-in-water single emulsion method and a quality-by-design approach was adopted to define the optimal operating space (OOS). Four critical process parameters (CPPs) were identified, including the acetone concentration in the water phase, the stabilizer [polyvinylalcohol (PVA)] concentration, the lipid-to-total solid ratio, and the total concentration. The CPPs were linked to critical quality attributes consisting of the particle size, polydispersity index (PDI), zeta-potential, thermotropic phase behavior, yield and stability. A central composite face-centered design was performed followed by multiple linear regression analysis. The size, PDI, enthalpy of the phase transition and yield were successfully modeled, whereas the models for the zeta-potential and the stability were poor. Cryo-transmission electron microscopy revealed that the main structural effect on the nanoparticle architecture is caused by the use of PVA, and two different morphologies were identified: i) A PLGA core coated with one or several concentric lipid bilayers, and ii) a PLGA nanoshell encapsulating lipid membrane structures. The optimal formulation, identified from the OOS, was evaluated in vivo. The hybrid NPs induced antibody and Th1/Th17 immune responses that were similar in quality and magnitude to the response induced by DDA/TDB liposomes, showing that the adjuvant
Bestard-Escalas, Joan; Garate, Jone; Maimó-Barceló, Albert; Fernández, Roberto; Lopez, Daniel Horacio; Lage, Sergio; Reigada, Rebeca; Khorrami, Sam; Ginard, Daniel; Reyes, José; Amengual, Isabel; Fernández, José A; Barceló-Coblijn, Gwendolyn
Membrane lipids are gaining increasing attention in the clinical biomarker field, as they are associated with different pathologic processes such as cancer or neurodegenerative diseases. Analyzing human colonoscopic sections by matrix assisted laser/desorption ionization (MALDI) mass spectrometry imaging techniques, we identified a defined number of lipid species changing concomitant to the colonocyte differentiation and according to a quite simple mathematical expression. These species felt into two lipid families tightly associated in signaling: phosphatidylinositols and arachidonic acid-containing lipids. On the other hand, an opposed pattern was observed in lamina propria for AA-containing lipids, coinciding with the physiological distribution of the immunological response cells in this tissue. Importantly, the lipid gradient was accompanied by a gradient in expression of enzymes involved in lipid mobilization. Finally, both lipid and protein gradients were lost in adenomatous polyps. The latter allowed us to assess how different a single lipid species is handled in a pathological context depending on the cell type. The strict patterns of distribution in lipid species and lipid enzymes described here unveil the existence of fine regulatory mechanisms orchestrating the lipidome according to the physiological state of the cell. In addition, these results provide solid evidence that the cell lipid fingerprint image can be used to predict precisely the physiological and pathological status of a cell, reinforcing its translational impact in clinical research.
Simovic, Spomenka; Barnes, Timothy J.; Tan, Angel; Prestidge, Clive A.
Lipid based colloids (e.g. emulsions and liposomes) are widely used as drug delivery systems, but often suffer from physical instabilities and non-ideal drug encapsulation and delivery performance. We review the application of engineered nanoparticle layers at the interface of lipid colloids to improve their performance as drug delivery systems. In addition we focus on the creation of novel hybrid nanomaterials from nanoparticle-lipid colloid assemblies and their drug delivery applications. Specifically, nanoparticle layers can be engineered to enhance the physical stability of submicron lipid emulsions and liposomes, satbilise encapsulated active ingredients against chemical degradation, control molecular transport and improve the dermal and oral delivery characteristics, i.e. increase absorption, bioavailability and facilitate targeted delivery. It is feasible that hybrid nanomaterials composed of nanoparticles and colloidal lipids are effective encapsulation and delivery systems for both poorly soluble drugs and biological drugs and may form the basis for the next generation of medicines. Additional pre-clinical research including specific animal model studies are required to advance the peptide/protein delivery systems, whereas the silica lipid hybrid systems have now entered human clinical trials for poorly soluble drugs.
Severino, Patrícia; Andreani, Tatiana; Macedo, Ana Sofia; Fangueiro, Joana F; Santana, Maria Helena A; Silva, Amélia M; Souto, Eliana B
Lipids and lipid nanoparticles are extensively employed as oral-delivery systems for drugs and other active ingredients. These have been exploited for many features in the field of pharmaceutical technology. Lipids usually enhance drug absorption in the gastrointestinal tract (GIT), and when formulated as nanoparticles, these molecules improve mucosal adhesion due to small particle size and increasing their GIT residence time. In addition, lipid nanoparticles may also protect the loaded drugs from chemical and enzymatic degradation and gradually release drug molecules from the lipid matrix into blood, resulting in improved therapeutic profiles compared to free drug. Therefore, due to their physiological and biodegradable properties, lipid molecules may decrease adverse side effects and chronic toxicity of the drug-delivery systems when compared to other of polymeric nature. This paper highlights the importance of lipid nanoparticles to modify the release profile and the pharmacokinetic parameters of drugs when administrated through oral route.
Zhu, Xiali; Huang, Shengnan; Xie, Yingxia; Zhang, Huijuan; Hou, Lin; Zhang, Yingjie; Huang, Heqing; Shi, Jinjin; Wang, Lei; Zhang, Zhenzhong
Single-walled carbon nanotubes (SWNT) possess high-near-infrared absorption coefficient, large surface area, and have great potential in drug delivery. In this study, we obtained ultrashort oxidized SWNT (OSWNT) using mixed acid oxidation method. Then, docetaxel (DTX) and folic acid (FA) are conjugated with OSWNT via π- π accumulation and amide linkage, respectively. A targeting and photothermal sensitive drug delivery system FA-DTX-OSWNT-SLN was prepared following a microemulsion technique. The size and zeta potential of FA-DTX-OSWNT-SLN were 182.8 ± 2.8 nm and -34.59 ± 1.50 mV, respectively. TEM images indicated that FA-DTX-OSWNT-SLN was spherical and much darker than general solid lipid nanoparticles (SLN). Furthermore, OSWNT may wind round, insert into or be encapsulated into the nanocarriers. Compared with free DTX, FA-DTX-OSWNT-SLN could efficiently cross cell membranes and afford higher antitumor efficacy in MCF-7 cells in vitro. Meanwhile, the combination of near-infrared laser (NIR) irradiation at 808 nm significantly enhanced cell inhibition. In conclusion, FA-DTX-OSWNT-SLN drug delivery system in combination with 808 nm NIR laser irradiation may be promising for targeting and photothermal cancer therapy with multiple mechanisms in future.
Garg, Neeraj K; Singh, Bhupinder; Jain, Ashay; Nirbhavane, Pradip; Sharma, Rajeev; Tyagi, Rajeev K; Kushwah, Varun; Jain, Sanyog; Katare, Om Prakash
The present study is designed to engineer fucose anchored methotrexate loaded solid lipid nanoparticles (SLNs) to target breast cancer. The developed nano-carriers were characterized with respect to particle size, PDI, zeta potential, drug loading and entrapment, in-vitro release etc. The characterized formulations were used to comparatively assess cellular uptake, cell-viability, apoptosis, lysosomal membrane permeability, bioavailability, biodistribution, changes in tumor volume and animal survival. The ex-vivo results showed greater cellular uptake and better cytotoxicity at lower IC50 of methotrexate in breast cancer cells. Further, we observed increased programmed cell death (apoptosis) with altered lysosomal membrane permeability and better rate of degradation of lysosomal membrane in-vitro. On the other hand, in-vivo evaluation showed maximum bioavailability and tumor targeting efficiency with minimum secondary drug distribution in various organs with formulated and anchored nano-carrier when compared with free drug. Moreover, sizeable reduction in tumor burden was estimated with fucose decorated SLNs as compared to that seen with free MTX and SLNs-MTX. Fucose decorated SLNs showed promising results to develop therapeutic interventions for breast cancer, and paved a way to explore this promising and novel nano-carrier which enables to address breast cancer.
Ruge, Christian A; Schaefer, Ulrich F; Herrmann, Jennifer; Kirch, Julian; Cañadas, Olga; Echaide, Mercedes; Pérez-Gil, Jesús; Casals, Cristina; Müller, Rolf; Lehr, Claus-Michael
The peripheral lungs are a potential entrance portal for nanoparticles into the human body due to their large surface area. The fact that nanoparticles can be deposited in the alveolar region of the lungs is of interest for pulmonary drug delivery strategies and is of equal importance for toxicological considerations. Therefore, a detailed understanding of nanoparticle interaction with the structures of this largest and most sensitive part of the lungs is important for both nanomedicine and nanotoxicology. Astonishingly, there is still little known about the bio-nano interactions that occur after nanoparticle deposition in the alveoli. In this study, we compared the effects of surfactant-associated protein A (SP-A) and D (SP-D) on the clearance of magnetite nanoparticles (mNP) with either more hydrophilic (starch) or hydrophobic (phosphatidylcholine) surface modification by an alveolar macrophage (AM) cell line (MH-S) using flow cytometry and confocal microscopy. Both proteins enhanced the AM uptake of mNP compared with pristine nanoparticles; for the hydrophilic ST-mNP, this effect was strongest with SP-D, whereas for the hydrophobic PL-mNP it was most pronounced with SP-A. Using gel electrophoretic and dynamic light scattering methods, we were able to demonstrate that the observed cellular effects were related to protein adsorption and to protein-mediated interference with the colloidal stability. Next, we investigated the influence of various surfactant lipids on nanoparticle uptake by AM because lipids are the major surfactant component. Synthetic surfactant lipid and isolated native surfactant preparations significantly modulated the effects exerted by SP-A and SP-D, respectively, resulting in comparable levels of macrophage interaction for both hydrophilic and hydrophobic nanoparticles. Our findings suggest that because of the interplay of both surfactant lipids and proteins, the AM clearance of nanoparticles is essentially the same, regardless of different
Wong, Priscilla Chui Hong; Heng, Paul Wan Sia; Chan, Lai Wah
This study was used to find solid state characteristics of ibuprofen loaded spray-congealed solid lipid microparticles (SLMs) by employing simple lipids as matrices, with or without polymeric additives, and the impact of solid drug-matrix miscibility on sustaining drug release. Solid miscibility of ibuprofen with two lipids, cetyl alcohol (CA) and stearic acid (SA), were investigated using differential scanning calorimetry (DSC). SLMs containing 20% w/w ibuprofen with or without polymeric additives, PVP/VA and EC, were produced by spray congealing, and the resultant microparticles were subjected to visual examination by scanning electron microscopy (SEM), thermal analysis using DSC, and hot-stage microscopy. Intermolecular interactions between lipids and drug as well as additives were investigated by Fourier-transformed infrared spectroscopy (FTIR) and nuclear magnetic resonance spectroscopy (NMR). X-ray diffractometry (XRD) was utilized to study polymorphic changes of drug and matrix over the course of a year. Ibuprofen was found to depress the melting points of CA and SA in a colligative manner, reaching maximum solubility at 10% w/w and 30% w/w for CA and SA, respectively. Drug encapsulation efficiencies and yields of spray-congealed SLMs containing 20% w/w ibuprofen were consistently high for both lipid matrices. CA and SA were found to adopt their stable γ- and β-polymorphs, respectively, immediately after spray congealing. The spray congealing process resulted in ibuprofen adopting an amorphous or poorly crystalline state, with no further changes over the course of a year. SEM, DSC, and hot stage microscope studies on the SLMs confirmed the formation of a solid dispersion between ibuprofen and CA and a solid solution between ibuprofen and SA. SA was found to sustain the release of ibuprofen significantly better than CA. PVP/VA and EC showed some interactions with CA, which led to an expansion of unit cell dimensions of CA upon spray congealing, whereas they
Wang, Jinping; Yan, Ran; Guo, Fang; Yu, Meng; Tan, Fengping; Li, Nan
Designing a targeted and versatile photothermal agent for the integration of precise diagnosis and effective photothermal treatment of tumors is desirable but remains a great challenge. In this study, folic acid ligand conjugated lipid-coated polyaniline hybrid nanoparticles (FA-Lipid-PANI NPs) were successfully fabricated by a distinctive technology. The obtained hybrid FA-Lipid-PANI NPs with small size exhibited not only significant photoacoustic (PA) imaging signals, but also a remarkable photothermal effect for tumor treatment. With PA imaging and photothermal therapy (PTT), the tumor could be accurately positioned and thoroughly eradicated in vivo after intravenous injection of FA-Lipid-PANI NPs. These multifunctional nanoparticles could play an important role in simultaneously facilitating imaging and PTT to achieve better therapeutic efficacy.
Kovacevic, A; Savic, S; Vuleta, G; Müller, R H; Keck, C M
The two polyhydroxy surfactants polyglycerol 6-distearate (Plurol(®)Stearique WL1009 - (PS)) and caprylyl/capryl glucoside (Plantacare(®) 810 - (PL)) are a class of PEG-free stabilizers, made from renewable resources. They were investigated for stabilization of aqueous solid lipid nanoparticle (SLN) and nanostructured lipid carrier (NLC) dispersions. Production was performed by high pressure homogenization, analysis by photon correlation spectroscopy (PCS), laser diffraction (LD), zeta potential measurements and differential scanning calorimetry (DSC). Particles were made from Cutina CP as solid lipid only (SLN) and its blends with Miglyol 812 (NLC, the blends containing increasing amounts of oil from 20% to 60%). The obtained particle sizes were identical for both surfactants, about 200 nm with polydispersity indices below 0.20 (PCS), and unimodal size distribution (LD). All dispersions with both surfactants were physically stable for 3 months at room temperature, but Plantacare (PL) showing a superior stability. The melting behaviour and crystallinity of bulk lipids/lipid blends were compared to the nanoparticles. Both were lower for the nanoparticles. The crystallinity of dispersions stabilized with PS was higher, the zeta potential decreased with storage time associated with this higher crystallinity, and leading to a few, but negligible larger particles. The lower crystallinity particles stabilized with PL remained unchanged in zeta potential (about -50 mV) and in size. These data show that surfactants have a distinct influence on the particle matrix structure (and related stability and drug loading), to which too little attention was given by now. Despite being from the same surfactant class, the differences on the structure are pronounced. They are attributed to the hydrophobic-lipophilic tail structure with one-point anchoring in the interface (PL), and the loop conformation of PS with two hydrophobic anchor points, i.e. their molecular structure and its
Bendix, Poul M; Reihani, S Nader S; Oddershede, Lene B
Absorption of electromagnetic irradiation results in significant heating of metallic nanoparticles, an effect which can be advantageously used in biomedical contexts. Also, metallic nanoparticles are presently finding widespread use as handles, contacts, or markers in nanometer scale systems, and for these purposes it is essential that the temperature increase associated with electromagnetic irradiation is not harmful to the environment. Regardless of whether the heating of metallic nanoparticles is desired or not, it is crucial for nanobio assays to know the exact temperature increase associated with electromagnetic irradiation of metallic nanoparticles. We performed direct measurements of the temperature surrounding single gold nanoparticles optically trapped on a lipid bilayer, a biologically relevant matrix. The lipid bilayer had incorporated fluorescent molecules which have a preference for either fluid or gel phases. The heating associated with electromagnetic radiation was measured by visualizing the melted footprint around the irradiated particle. The effect was measured for individual gold nanoparticles of a variety of sizes and for a variety of laser powers. The temperatures were highly dependent on particle size and laser power, with surface temperature increments ranging from a few to hundreds of degrees Celsius. Our results show that by a careful choice of gold nanoparticle size and strength of irradiating electromagnetic field, one can control the exact particle temperature. The method is easily applicable to any type of nanoparticle for which the photothermal effect is sought to be quantified.
The purpose of the thesis was to quantify ketoprofen (KTP) in rabbit skin following the topical application of lipid nanoparticles (Nanostructured lipid carriers, NLC). We tested two different types of formulations: one is (G') in which KTP is incorporated within the nanostructured lipid carriers (NLC) and the other is (H') which is a mixture of the nanostructured lipid carriers (NLC) and KTP dissolved in a vehicle (10% glycerol + 1% xanthan gum). Ketoprofen (KTP) is a non-steroidal anti-inflammatory drug administered systemically to treat arthritis. By conventional route severe side effects at the gastrointestinal level have been observed. Topical-application of lipid nanoparticles would be convenient alternative. The project is based on the (1) To study the calibration of microdialysis probes in both environment, in vivo as well as in vitro; (2) To compare two different type of formulation one is (G') with KTP incorporated within the nanostructured lipid carriers (NLC) and the other is (H') a mixture of the nanostructured lipid carriers (NLC) and KTP dissolved in a the vehicle (10% glycerol + 1% xanthan gum). The results of this study show a clear difference between the skin concentration profiles of the two formulations. Time to reach the maximum concentration is similar for both formulations. The formulation H', containing KTP is in external phase had higher Cmax (334ng/ml) than formulation G' containing KTP inside lipid particles (Cmax 32ng/ml).
Dehaini, Diana; Fang, Ronnie H.; Luk, Brian T.; Pang, Zhiqing; Hu, Che-Ming J.; Kroll, Ashley V.; Yu, Chun Lai; Gao, Weiwei; Zhang, Liangfang
Lipid-polymer hybrid nanoparticles, consisting of a polymeric core coated by a layer of lipids, are a class of highly scalable, biodegradable nanocarriers that have shown great promise in drug delivery applications. Here, we demonstrate the facile synthesis of ultra-small, sub-25 nm lipid-polymer hybrid nanoparticles using an adapted nanoprecipitation approach and explore their utility for targeted delivery of a model chemotherapeutic. The fabrication process is first optimized to produce a monodisperse population of particles that are stable under physiological conditions. It is shown that these ultra-small hybrid nanoparticles can be functionalized with a targeting ligand on the surface and loaded with drug inside the polymeric matrix. Further, the in vivo fate of the nanoparticles after intravenous injection is characterized by examining the blood circulation and biodistribution. In a final proof-of-concept study, targeted ultra-small hybrid nanoparticles loaded with the cancer drug docetaxel are used to treat a mouse tumor model and demonstrate improved efficacy compared to a clinically available formulation of the drug. The ability to synthesize a significantly smaller version of the established lipid-polymer hybrid platform can ultimately enhance its applicability across a wider range of applications.
A novel strategy for the treatment of chronic wounds based on the topical administration of rhEGF-loaded lipid nanoparticles: In vitro bioactivity and in vivo effectiveness in healing-impaired db/db mice.
Gainza, Garazi; Pastor, Marta; Aguirre, José Javier; Villullas, Silvia; Pedraz, José Luis; Hernandez, Rosa Maria; Igartua, Manoli
Lipid nanoparticles are currently receiving increasing interest because they permit the topical administration of proteins, such as recombinant human epidermal growth factor (rhEGF), in a sustained and effective manner. Because chronic wounds have become a major healthcare burden, the topical administration of rhEGF-loaded lipid nanoparticles, namely solid lipid nanoparticles (SLN) and nanostructured lipid carries (NLC), appears to be an interesting and suitable strategy for the treatment of chronic wounds. Both rhEGF-loaded lipid nanoparticles were prepared through the emulsification-ultrasonication method; however, the NLC-rhEGF preparation did not require the use of any organic solvents. The characterisation of the nanoparticles (NP) revealed that the encapsulation efficiency (EE) of NLC-rhEGF was significantly greater than obtained with SLN-rhEGF. The in vitro experiments demonstrated that gamma sterilisation is a suitable process for the final sterilisation because no loss in activity was observed after the sterilisation process. In addition, the proliferation assays revealed that the bioactivity of the nanoformulations was even higher than that of free rhEGF. Finally, the effectiveness of the rhEGF-loaded lipid nanoparticles was assayed in a full-thickness wound model in db/db mice. The data demonstrated that four topical administrations of SLN-rhEGF and NLC-rhEGF significantly improved healing in terms of wound closure, restoration of the inflammatory process, and re-epithelisation grade. In addition, the data did not reveal any differences in the in vivo effectiveness between the different rhEGF-loaded lipid nanoparticles. Overall, these findings demonstrate the promising potential of rhEGF-loaded lipid nanoparticles, particularly NLC-rhEGF, for the promotion of faster and more effective healing and suggest their future application for the treatment of chronic wounds.
Joyce, Paul; Whitby, Catherine P; Prestidge, Clive A
Biodegradable and bioactive hybrid particles composed of poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles and medium-chain triglycerides were prepared by spray drying lipid-in-water emulsions stabilized by PLGA nanoparticles, to form PLGA-lipid hybrid (PLH) microparticles approximately 5 μm in mean diameter. The nanoparticle stabilizer was varied and mannitol was also incorporated during the preparation to investigate the effect of stabilizer charge and cryoprotectant content on the particle microstructure. An in vitro lipolysis model was used to demonstrate the particles' bioactivity by manipulating the digestion kinetics of encapsulated lipid by pancreatic lipase in simulated gastrointestinal fluid. Lipid digestion kinetics were enhanced in PLH and PLGA-lipid-mannitol hybrid (PLMH) microparticles for both stabilizers, compared to a coarse emulsion, in biorelevant media. An optimal digestion rate was observed for the negatively charged PLMH system, evidenced by a 2-fold increase in the pseudo-first-order rate constant compared to a coarse emulsion. Improved microparticle redispersion, probed by dual dye confocal fluorescence microscopy, increased the available surface area of lipid for lipase adsorption, enhancing digestion kinetics. Thereby, lipase action was controlled in hybrid microparticles by altering the surface charge and carbohydrate content. Our results demonstrate that bioactive microparticles composed of versatile and biodegradable polymeric particles and oil droplets have great potential for use in smart food and nutrient delivery, as well as safer and more efficacious oral delivery of drugs and drug combinations.
Neupane, Yub Raj; Sabir, M. D.; Ahmad, Nafees; Ali, Mushir; Kohli, Kanchan
The purpose of this study was to develop lipid drug conjugate (LDC) nanoparticles of decitabine (DCB) using stearic acid as a lipid to increase the permeability of the drug along with its protection from chemical degradation. The LDC was prepared by salt formation of DCB with stearic acid and followed by cold homogenization technique to produce the LDC nanoparticles. The role of key independent variables influencing on dependent variables were determined by using a Box-Behnken design. The optimized batch revealed spherical morphology under TEM analysis with particle size of 202.6 ± 1.65 nm and 0.334 ± 0.987 PDI. The zeta potential and %EE were found to be -33.6 ± 0.845 mV and 68.89% ± 0.59 respectively. Lyophilized powder showed the crystalline structure under DSC analysis. In vitro release studies showed the initial burst release followed by a sustained release up to 24 h in PBS pH 7.4 and the data were further studied using release kinetic models which revealed the first-order model as a best-fitting model. Ex vivo gut permeation studies proved that the formulation containing lipid and surfactants has a higher permeability than the plain drug solution with nearly fourfold increase in the apparent permeability coefficients. Finally, LDC nanoparticles prepared by using stearic acid as a lipid and surfactants as Tween 80, Poloxamer 188, and Labrasol in equal ratio possess high potential for the oral delivery of hydrophilic drugs.
Gomes, Maria João; Fernandes, Carlos; Martins, Susana; Borges, Fernanda; Sarmento, Bruno
Blood-brain barrier is a tightly packed layer of endothelial cells surrounding the brain that acts as the main obstacle for drugs enter the central nervous system (CNS), due to its unique features, as tight junctions and drug efflux systems. Therefore, since the incidence of CNS disorders is increasing worldwide, medical therapeutics need to be improved. Consequently, aiming to surpass blood-brain barrier and overcome CNS disabilities, silencing P-glycoprotein as a drug efflux transporter at brain endothelial cells through siRNA is considered a promising approach. For siRNA enzymatic protection and efficient delivery to its target, two different nanoparticles platforms, solid lipid (SLN) and poly-lactic-co-glycolic (PLGA) nanoparticles were used in this study. Polymeric PLGA nanoparticles were around 115 nm in size and had 50 % of siRNA association efficiency, while SLN presented 150 nm and association efficiency close to 52 %. Their surface was functionalized with a peptide-binding transferrin receptor, in a site-oriented manner confirmed by NMR, and their targeting ability against human brain endothelial cells was successfully demonstrated by fluorescence microscopy and flow cytometry. The interaction of modified nanoparticles with brain endothelial cells increased 3-fold compared to non-modified lipid nanoparticles, and 4-fold compared to non-modified PLGA nanoparticles, respectively. These nanosystems, which were also demonstrated to be safe for human brain endothelial cells, without significant cytotoxicity, bring a new hopeful breath to the future of brain diseases therapies.
Valencia, Pedro M; Basto, Pamela A; Zhang, Liangfang; Rhee, Minsoung; Langer, Robert; Farokhzad, Omid C; Karnik, Rohit
A key challenge in the synthesis of multicomponent nanoparticles (NPs) for therapy or diagnosis is obtaining reproducible monodisperse NPs with a minimum number of preparation steps. Here we report the use of microfluidic rapid mixing using hydrodynamic flow focusing in combination with passive mixing structures to realize the self-assembly of monodisperse lipid-polymer and lipid-quantum dot (QD) NPs in a single mixing step. These NPs are composed of a polymeric core for drug encapsulation or a QD core for imaging purposes, a hydrophilic polymeric shell, and a lipid monolayer at the interface of the core and the shell. In contrast to slow mixing of lipid and polymeric solutions, rapid mixing directly results in formation of homogeneous NPs with relatively narrow size distribution that obviates the need for subsequent thermal or mechanical agitation for homogenization. We identify rapid mixing conditions that result in formation of homogeneous NPs and show that self-assembly of polymeric core occurs independent of the lipid component, which only provides stability against aggregation over time and in the presence of high salt concentrations. Physicochemical properties of the NPs including size (35-180 nm) and zeta potential (-10 to +20 mV in PBS) are controlled by simply varying the composition and concentration of precursors. This method for preparation of hybrid NPs in a single mixing step may be useful for combinatorial synthesis of NPs with different properties for imaging and drug delivery applications.
Müller, R H; Petersen, R D; Hommoss, A; Pardeike, J
The first generation of lipid nanoparticles was introduced as solid lipid nanoparticles (SLN), the second, improved generation as nanostructured lipid carriers (NLC). Identical to the liposomes, the lipid nanoparticles (NLC) appeared as products first on the cosmetic market. The article gives an overview of the cosmetic benefits of lipid nanoparticles, that means enhancement of chemical stability of actives, film formation, controlled occlusion, skin hydration, enhanced skin bioavailability and physical stability of the lipid nanoparticles as topical formulations. NLC are on the market as concentrates to be used as cosmetic excipients, special formulation challenges for these products are discussed. NLC appeared also in a number of finished cosmetic products world-wide. An overview of these products is provided including their special effects due to the lipid nanoparticles, lipids used for their production and incorporated cosmetic actives.
Peetla, Chiranjeevi; Vijayaraghavalu, Sivakumar; Labhasetwar, Vinod
In this review, we focus on the biophysics of cell membrane lipids, particularly when cancers develop acquired drug resistance, and how biophysical changes in resistant cell membrane influence drug transport and nanoparticle-mediated drug delivery. Recent advances in membrane lipid research show the varied roles of lipids in regulating membrane P-glycoprotein function, membrane trafficking, apoptotic pathways, drug transport, and endocytic functions, particularly endocytosis, the primary mechanism of cellular uptake of nanoparticle-based drug delivery systems. Since acquired drug resistance alters lipid biosynthesis, understanding the role of lipids in cell membrane biophysics and its effect on drug transport is critical for developing effective therapeutic and drug delivery approaches to overcome drug resistance. Here we discuss novel strategies for (a) modulating the biophysical properties of membrane lipids of resistant cells to facilitate drug transport and regain endocytic function and (b) developing effective nanoparticles based on their biophysical interactions with membrane lipids to enhance drug delivery and overcome drug resistance.
Al-Qushawi, Alwan; Rassouli, Ali; Atyabi, Fatemeh; Peighambari, Seyed Mostafa; Esfandyari-Manesh, Mehdi; Shams, Gholam Reza; Yazdani, Azam
Tilmicosin (TLM) is an important antibiotic in veterinary medicine with low bioavailability and safety. This study aimed to formulate and evaluate physicochemical properties, storage stability after lyophilization, and antibacterial activity of three TLM-loaded lipid nanoparticles (TLM-LNPs) including solid lipid nanoparticles (SLNs), nanostructured lipid carriers (NLCs), and lipid-core nanocapsules (LNCs). Physicochemical parameters such as particle size-mean diameter, polydispersity index, zeta potential, drug encapsulation efficiency (EE), loading capacity, and morphology of the formulations were evaluated and the effects of various cryoprotectants during lyophilization and storage for 8 weeks were also studied. The profiles of TLM release and the antibacterial activities of these TLM-LNPs suspensions (against Escherichia coli and Staphylococcus aureus) were tested in comparison with their corresponding powders. TLM-LNPs suspensions were in nano-scale range with mean diameters of 186.3 ± 1.5, 149.6 ± 3.0, and 85.0 ± 1.0nm, and also EE, 69.1, 86.3, and 94.3% for TLM- SLNs, TLM-NLCs, and TLM- LNCs respectively. TLM-LNCs gave the best results with significantly low particle size and high EE (p<0.05). Mannitol was the most effective cryoprotectant for lyophilization and storage of TLM-LNPs. The drug release profiles were biphasic and the release times were longer at pH 7.4 where TLM-NLCs and TLM-LNCs powders showed longer release times. In microbiological tests, S. aureus was about 4 times more sensitive than E. coli to TLM-LNPs with minimum inhibitory concentration ranges of 0.5-1.0 and 2-4 µg/mL respectively, and TLM-LNCs exhibited the best antibacterial activities. In conclusion, TLM-LNP formulations especially TLM-LNCs and TLM-NLCs are promising carriers for TLM with better drug encapsulation capacity, release behavior, and antibacterial activity. PMID:28261309
Clark, Andrea J.; Petty, Howard R.
Although metal-metal oxide nanoparticles have attracted considerable interest as catalysts, they have attracted little interest in nanomedicine. This is likely due to the fact that metal oxide semiconductors generally require biologically harmful ultraviolet excitation. In contrast, this study focuses upon WO3/Pt nanoparticles, which can be excited by visible light. To optimize the nanoparticles’ catalytic performance, platinization was performed at alkaline pH. These nanoparticles destroyed organic dyes, consumed dissolved oxygen and produced hydroxyl radicals. 4T1 breast cancer cells internalized WO3/Pt nanoparticles within the membrane-bound endo-lysosomal compartment as shown by electron and fluorescence microscopy. During visible light exposure, but not in darkness, WO3/Pt nanoparticles manufacture reactive oxygen species, promote lipid peroxidation, and trigger lysosomal membrane disruption. As cells of the immune system degrade organic molecules, produce reactive oxygen species, and activate the lipid peroxidation pathway within target cells, these nanoparticles mimic the chemical attributes of immune effector cells. These biomimetic nanoparticles should become useful in managing certain cancers, especially ocular cancer.
Mhashal, Anil R; Roy, Sudip
Herein, we study the permeation free energy of bare and octane-thiol-capped gold nanoparticles (AuNPs) translocating through a lipid membrane. To investigate this, we have pulled the bare and capped AuNPs from bulk water to the membrane interior and estimated the free energy cost. The adsorption of the bare AuNP on the bilayer surface is energetically favorable but further loading inside it requires energy. However, the estimated free-energy barrier for loading the capped AuNP into the lipid membrane is much higher compared to bare AuNP. We also demonstrate the details of the permeation process of bare and capped AuNPs. Bare AuNP induces the curvature in the lipid membrane whereas capped AuNP creates an opening in the interacting monolayer and get inserted into the membrane. The insertion of capped AuNP induces a partial unzipping of the lipid bilayer, which results in the ordering of the local lipids interacting with the nanoparticle. However, bare AuNP disrupts the lipid membrane by pushing the lipid molecules inside the membrane. We also analyze pore formation due to the insertion of capped AuNP into the membrane, which results in water molecules penetrating the hydrophobic region.
Xia, Yan; Li, Ming; Charubin, Kamil; Liu, Ying; Heberle, Frederick A.; Katsaras, John; Jing, Benxin; Zhu, Yingxi; Nieh, Mu-Ping
In this paper, we report on studies of lipid transfer rates between different morphology nanoparticles and lipids with different length acyl chains. The lipid transfer rate of dimyristoylphosphatidylcholine (di-C14, DMPC) in discoidal “bicelles” (0.156 h–1) is 2 orders of magnitude greater than that of DMPC vesicles (ULVs) (1.1 × 10–3 h–1). For both bicellar and ULV morphologies, increasing the acyl chain length by two carbons [going from di-C14 DMPC to di-C16, dipalmitoylphosphatidylcholine (DPPC)] causes lipid transfer rates to decrease by more than 2 orders of magnitude. Results from small angle neutron scattering (SANS), differential scanning calorimetry (DSC), and fluorescence correlation spectroscopy (FCS) are in good agreement. Finally, the present studies highlight the importance of lipid dynamic processes taking place in different morphology biomimetic membranes.
Xia, Yan; Li, Ming; Charubin, Kamil; ...
In this paper, we report on studies of lipid transfer rates between different morphology nanoparticles and lipids with different length acyl chains. The lipid transfer rate of dimyristoylphosphatidylcholine (di-C14, DMPC) in discoidal “bicelles” (0.156 h–1) is 2 orders of magnitude greater than that of DMPC vesicles (ULVs) (1.1 × 10–3 h–1). For both bicellar and ULV morphologies, increasing the acyl chain length by two carbons [going from di-C14 DMPC to di-C16, dipalmitoylphosphatidylcholine (DPPC)] causes lipid transfer rates to decrease by more than 2 orders of magnitude. Results from small angle neutron scattering (SANS), differential scanning calorimetry (DSC), and fluorescence correlationmore » spectroscopy (FCS) are in good agreement. Finally, the present studies highlight the importance of lipid dynamic processes taking place in different morphology biomimetic membranes.« less
Boldrin, Paul; Ruiz-Trejo, Enrique; Yu, Jingwen; ...
Incorporation of nanoparticles into devices such as solid oxide fuel cells (SOFCs) may provide benefits such as higher surface areas or finer control over microstructure. However, their use with traditional fabrication techniques such as screen-printing is problematic. Here, we show that mixing larger commercial particles with nanoparticles allows traditional ink formulation and screen-printing to be used while still providing benefits of nanoparticles such as increased porosity and lower sintering temperatures. SOFC anodes were produced by impregnating ceria–gadolinia (CGO) scaffolds with nickel nitrate solution. The scaffolds were produced from inks containing a mixture of hydrothermally-synthesised n