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1.
Pharmaceutics ; 16(6)2024 Jun 14.
Article in English | MEDLINE | ID: mdl-38931933

ABSTRACT

In this study, we present a new type of polymer-free hydrogel made only from nonionic surfactants, oil, and water. Such a system is produced by taking advantage of the physicochemical behavior and interactions between nonionic surfactants and oil and water phases, according to a process close to spontaneous emulsification used in the production of nano-emulsions. Contrary to the classical process of emulsion-based gel formulation, we propose a simple one-step approach. Beyond the originality of the concept, these nanoemulgels appear as very promising systems able to encapsulate and deliver various molecules with different solubilities. In the first section, we propose a comprehensive investigation of the gel formation process and its limits through oscillatory rheological characterization, characterization of the sol/gel transitions, and gel strength. The second section is focused on the follow-up of the release of an encapsulated model hydrophilic molecule and on the impact of the rheological gel properties on the release profiles.

2.
Pharmaceutics ; 16(2)2024 Jan 24.
Article in English | MEDLINE | ID: mdl-38399224

ABSTRACT

Flurbiprofen (FBP), a nonsteroidal anti-inflammatory drug (NSAID), is commonly used to treat the pain of rheumatoid arthritis, but in prolonged use it causes gastric irritation and ulcer. To avoid these adverse events of NSAIDs, the simultaneous administration of H2 receptor antagonists such as ranitidine hydrochloride (RHCl) is obligatory. Here, we developed composite oral fast-disintegrating films (ODFs) containing FBP along with RHCl to provide a gastroprotective effect as well as to enhance the solubility and bioavailability of FBP. The ternary solid dispersion (TSD) of FBP was fabricated with Syloid® 244FP and poloxamer® 188 using the solvent evaporation technique. The synthesized FBP-TSD (coded as TSD) was loaded alone (S1) and in combination with plain RHCl (S2) in the composite ODFs based on hydroxypropyl methyl cellulose E5 (HPMC E5). The synthesized composite ODFs were evaluated by in vitro (thickness, folding endurance, tensile strength, disintegration, SEM, FTIR, XRD and release study) and in vivo (analgesic, anti-inflammatory activity, pro-inflammatory cytokines and gastroprotective assay) studies. The in vitro characterization revealed that TSD preserved its integrity and was effectively loaded in S1 and S2 with optimal compatibility. The films were durable and flexible with a disintegration time ≈15 s. The release profile at pH 6.8 showed that the solid dispersion of FBP improved the drug solubility and release when compared with pure FBP. After in vitro studies, it was observed that the analgesic and anti-inflammatory activity of S2 was higher than that of pure FBP and other synthesized formulations (TSD and S1). Similarly, the level of cytokines (TNF-α and IL-6) was also markedly reduced by S2. Furthermore, a gastroprotective assay confirmed that S2 has a higher safety profile in comparison to pure FBP and other synthesized formulations (TSD and S1). Thus, composite ODF (S2) can effectively enhance the FBP solubility and its therapeutic efficacy, along with its gastroprotective effect.

3.
Phys Chem Chem Phys ; 25(2): 1177-1186, 2023 Jan 04.
Article in English | MEDLINE | ID: mdl-36519558

ABSTRACT

In this study, we explored how chemical reactions of amphiphile compounds can be characterized and followed-up on model interfaces. A custom-made surfactant containing three alkyne sites was first adsorbed and characterized at a water/oil interface. These amphiphiles then underwent interfacial crosslinking by click chemistry upon the addition of a second reactive agent. The monolayer properties and dilatational elasticity, were compared before and after the polymerization. Using bulk phase exchange, the composition of the aqueous bulk phase was finely controlled and washed to specifically measure the interfacial effects of the entities adsorbed and trapped at the interface. In this study, we aim to emphasize an original experimental approach to follow complex phenomena occurring on model interfaces, and also show the potential of this method to characterize multifactorial processes.


Subject(s)
Pulmonary Surfactants , Surface-Active Agents , Surface-Active Agents/chemistry , Water/chemistry , Click Chemistry , Adsorption
4.
Adv Drug Deliv Rev ; 179: 114019, 2021 12.
Article in English | MEDLINE | ID: mdl-34699940

ABSTRACT

Since antiquity, the survival of human civilization has always been threatened by the microbial infections. An alarming surge in the resistant microbial strains against the conventional drugs is quite evident in the preceding years. Furthermore, failure of currently available regimens of antibiotics has been highlighted by the emerging threat of biofilms in the community and hospital settings. Biofilms are complex dynamic composites rich in extracellular polysaccharides and DNA, supporting plethora of symbiotic microbial life forms, that can grow on both living and non-living surfaces. These enforced structures are impervious to the drugs and lead to spread of recurrent and non-treatable infections. There is a strong realization among the scientists and healthcare providers to work out alternative strategies to combat the issue of drug resistance and biofilms. Plants are a traditional but rich source of effective antimicrobials with wider spectrum due to presence of multiple constituents in perfect synergy. Other than the biocompatibility and the safety profile, these phytochemicals have been repeatedly proven to overcome the non-responsiveness of resistant microbes and films via multiple pathways such as blocking the efflux pumps, better penetration across the cell membranes or biofilms, and anti-adhesive properties. However, the unfavorable physicochemical attributes and stability issues of these phytochemicals have hampered their commercialization. These issues of the phytochemicals can be solved by designing suitably constructed nanoscaled structures. Nanosized systems can not only improve the physicochemical features of the encapsulated payloads but can also enhance their pharmacokinetic and therapeutic profile. This review encompasses why and how various types of phytochemicals and their nanosized preparations counter the microbial resistance and the biofouling. We believe that phytochemical in tandem with nanotechnological innovations can be employed to defeat the microbial resistance and biofilms. This review will help in better understanding of the challenges associated with developing such platforms and their future prospects.


Subject(s)
Anti-Bacterial Agents/pharmacology , Biofilms/drug effects , Nanoparticle Drug Delivery System/chemistry , Phytochemicals/pharmacology , Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/chemistry , Biofilms/growth & development , Cross Infection/microbiology , Drug Carriers , Drug Liberation , Drug Resistance, Multiple, Bacterial/physiology , Drug Stability , Equipment and Supplies/microbiology , Humans , Particle Size , Phytochemicals/administration & dosage , Phytochemicals/chemistry
5.
Nanomedicine ; 34: 102379, 2021 06.
Article in English | MEDLINE | ID: mdl-33713860

ABSTRACT

Endothelial senescence has been identified as an early event in the development of endothelial dysfunction, a hallmark of cardiovascular disease. This study developed theranostic nanocarriers (NC) decorated with VCAM-1 antibodies (NC-VCAM-1) in order to target cell surface VCAM-1, which is overexpressed in senescent endothelial cells (ECs) for diagnostic and therapeutic purposes. Incubation of Ang II-induced premature senescent ECs or replicative senescent ECs with NC-VCAM-1 loaded with lipophilic fluorescent dyes showed higher fluorescence signals than healthy EC, which was dependent on the NC size and VCAM-1 antibodies concentration, and not observed following masking of VCAM-1. NC loaded with omega 3 polyunsaturated fatty acid (NC-EPA:DHA6:1) were more effective than native EPA:DHA 6:1 to prevent Ang II-induced VCAM-1 and p53 upregulation, and SA-ß-galactosidase activity in coronary artery segments. These theranostic NC might be of interest to evaluate the extent and localization of endothelial senescence and to prevent pro-senescent endothelial responses.


Subject(s)
Cellular Senescence , Drug Carriers , Endothelium, Vascular/cytology , Fluorescent Dyes/chemistry , Vascular Cell Adhesion Molecule-1/metabolism , Animals , Autoantibodies/immunology , Cell Proliferation , Endothelium, Vascular/metabolism , Precision Medicine , Swine , Vascular Cell Adhesion Molecule-1/immunology
6.
Langmuir ; 37(8): 2586-2595, 2021 03 02.
Article in English | MEDLINE | ID: mdl-33577340

ABSTRACT

In this work, we used an original experimental setup to examine the behavior of insoluble monolayers made with pH-sensitive lipids. Two kinds of unsaturated lipids were chosen: a cationic one (lipid 1) bearing an ammonium headgroup and an anionic one (lipid 2) terminated with an acidic phenol group. The lipids were deposited onto an air bubble interface maintained in an aqueous phase and, after stabilization, were subjected to a series of compressions performed at different pH values. These experiments disclosed a gradual increase in the specific area per molecule when lipids were neutralized. Imposing a pH variation at constant bubble volume also provided surface pressure profiles that confirmed this molecular behavior. As complementary characterization, dilatational rheology disclosed a phase transition from a purely elastic monophasic system to a viscoelastic two-phase system. We hypothesized that this unexpected increase in the specific area with lipid neutralization is related to the presence of unsaturations in each of the two branches of the hydrophobic tails that induce disorder, thereby increasing the molecular area at the interface. Application of the two-dimensional Volmer equation of state allowed the generation of quantitative values for the specific areas that showed variations with pH. It also allowed the determination of apparent pKa values, which are affected by both the electrostatic potential within the monolayer and the affinity of the lipid polar head for the aqueous phase.

7.
J Colloid Interface Sci ; 578: 768-778, 2020 Oct 15.
Article in English | MEDLINE | ID: mdl-32574910

ABSTRACT

Nano-emulsion consists of a dispersion of oil droplets sizing below 200 nm, in aqueous continuous phase, and generally stabilized by low-molecular-weight surfactants. These stable nano-carriers are able to encapsulate and transport lipophilic molecules poorly soluble in water. However, the question on the leakage and release mechanisms of an active pharmaceutical ingredient, from oil nano-droplets to an acceptor medium has not been clearly addressed. Herein, we developed a simple fluorescence approach based on self-quenching of lipophilic fluorophore-based on Nile Red (NR668) to monitor cargo transfer from lipid nano-droplets to the acceptor medium. In this method, the fluorophore release can be monitored by the increase in its fluorescence quantum yield and the blue shift in its emission spectrum. The studies of the release process allow emphasizing an important role of the bulk aqueous medium in controlling the droplet to droplet fluorophore transfer and the attained equilibrium. The developed methodology could be applied to monitor release of other lipophilic dyes and it could help to better understand the cargo release from nanocarriers.

8.
Int J Pharm ; 585: 119481, 2020 Jul 30.
Article in English | MEDLINE | ID: mdl-32473375

ABSTRACT

Nanosized gel particles, so-called nanogels, have attracted substantial interest in different application fields, thanks to their controllable and three-dimensional physical structure, good mechanical properties and potential biocompatibility. Literature reports many technologies for their preparation and design, however a recurrent limitation remains in their broad size distributions as well as in the poor size control. Therefore, the monodisperse and size-controlled nanogels preparation by simple process -like emulsification- is a real challenge still in abeyance to date. In this study we propose an original low energy emulsification approach for the production of monodisperse nanogels, for which the size can be finely controlled in the range 30 to 200 nm. The principle lies in the fabrication of a direct nano-emulsion containing both oil (medium chain triglycerides) and a bi-functional acrylate monomer. The nanogels are thus formed in situ upon UV irradiation of the droplet suspension. Advantage of such modification of the oil nano-carriers are the potential modulation of the release of encapsulated drugs, as a function of the density and/or properties of the polymer chain network entrapped in the oil nano-droplets. This hypothesis was confirmed using a model of hydrophobic drug -ketoprofen- entrapped into the nanogels particles, along with the study of the release profile, carried out in function of the nature of the monomers, density of polymer chains, and different formulation parameters.


Subject(s)
Chemistry, Pharmaceutical/methods , Emulsions/chemical synthesis , Lipids/chemical synthesis , Nanogels/chemistry , Emulsions/metabolism , Hydrophobic and Hydrophilic Interactions , Ketoprofen/chemical synthesis , Ketoprofen/metabolism , Lipid Metabolism , Nanoparticles/chemistry , Nanoparticles/metabolism
9.
Pharmaceutics ; 11(11)2019 Nov 12.
Article in English | MEDLINE | ID: mdl-31726769

ABSTRACT

The current nanotechnology era is marked by the emergence of various magnetic inorganic nanometer-sized colloidal particles. These have been extensively applied and hold an immense potential in biomedical applications including, for example, cancer therapy, drug nanocarriers (NCs), or in targeted delivery systems and diagnosis involving two guided-nanoparticles (NPs) as nanoprobes and contrast agents. Considerable efforts have been devoted to designing iron oxide NPs (IONPs) due to their superparamagnetic (SPM) behavior (SPM IONPs or SPIONs) and their large surface-to-volume area allowing more biocompatibility, stealth, and easy bonding to natural biomolecules thanks to grafted ligands, selective-site moieties, and/or organic and inorganic corona shells. Such nanomagnets with adjustable architecture have been the topic of significant progresses since modular designs enable SPIONs to carry out several functions simultaneously such as local drug delivery with real-time monitoring and imaging of the targeted area. Syntheses of SPIONs and adjustments of their physical and chemical properties have been achieved and paved novel routes for a safe use of those tailored magnetic ferrous nanomaterials. Herein we will emphasis a basic notion about NPs magnetism in order to have a better understanding of SPION assets for biomedical applications, then we mainly focus on magnetite iron oxide owing to its outstanding magnetic properties. The general methods of preparation and typical characteristics of magnetite are reviewed, as well as the major biomedical applications of magnetite.

10.
J Pharm Pharmacol ; 71(8): 1185-1198, 2019 Aug.
Article in English | MEDLINE | ID: mdl-31049986

ABSTRACT

OBJECTIVES: This review highlights both the physicochemical characteristics of the nanocarriers (NCs) and the physiological features of tumour microenvironment (TME) to outline what strategies undertaken to deliver the molecules of interest specifically to certain lesions. This review discusses these properties describing the convenient choice between passive and active targeting mechanisms with details, illustrated with examples of targeting agents up to preclinical research or clinical advances. KEY FINDINGS: Targeted delivery approaches for anticancers have shown a steep rise over the past few decades. Though many successful preclinical trials, only few passive targeted nanocarriers are approved for clinical use and none of the active targeted nanoparticles. Herein, we review the principles and for both processes and the correlation with the tumour microenvironment. We also focus on the limitation and advantages of each systems regarding laboratory and industrial scale. SUMMARY: The current literature discusses how the NCs and the enhanced permeation and retention effect impact the passive targeting. Whereas the active targeting relies on the ligand-receptor binding, which improves selective accumulation to targeted sites and thus discriminates between the diseased and healthy tissues. The latter could be achieved by targeting the endothelial cells, tumour cells, the acidic environment of cancers and nucleus.


Subject(s)
Antineoplastic Agents/administration & dosage , Antineoplastic Agents/chemistry , Drug Carriers/chemistry , Nanoparticles/administration & dosage , Nanoparticles/chemistry , Neoplasms/drug therapy , Animals , Drug Delivery Systems/methods , Humans , Tumor Microenvironment/drug effects
11.
Pharm Res ; 36(6): 78, 2019 Apr 03.
Article in English | MEDLINE | ID: mdl-30945009

ABSTRACT

This review article presents the state-of-the-art in the major imaging modalities supplying relevant information on patient health by real-time monitoring to establish an accurate diagnosis and potential treatment plan. We draw a comprehensive comparison between all imagers and ultimately end with our focus on two main types of scanners: X-ray CT and MRI scanners. Numerous types of imaging probes for both imaging techniques are described, as well as reviewing their strengths and limitations, thereby showing the current need for the development of new diagnostic contrast agents (CAs). The role of nanoparticles in the design of CAs is then extensively detailed, reviewed and discussed. We show how nanoparticulate agents should be promising alternatives to molecular ones and how they are already paving new routes in the field of nanomedicine.


Subject(s)
Contrast Media , Diagnostic Imaging/methods , Diagnostic Imaging/trends , Nanomedicine/methods , Animals , Contrast Media/adverse effects , Contrast Media/chemistry , Diagnostic Imaging/instrumentation , Drug Delivery Systems , Humans , Molecular Structure , Nanomedicine/trends , Nanoparticles/adverse effects , Nanoparticles/chemistry , Particle Size , Polymers/chemistry , Surface Properties
12.
Langmuir ; 35(6): 2313-2325, 2019 Feb 12.
Article in English | MEDLINE | ID: mdl-30630316

ABSTRACT

Delivery systems able to coencapsulate both hydrophilic and hydrophobic species are of great interest in both fundamental research and industrial applications. Water-in-oil-in-water (w1/O/W2) emulsions are interesting systems for this purpose, but they suffer from limited stability. In this study, we propose an innovative approach to stabilize double emulsions by the synthesis of a silica membrane at the water/oil interface of the primary emulsion (i.e., inner w1/O emulsion). This approach allows the formulation of stable double emulsions through a two-step process, enabling high encapsulation efficiencies of model hydrophilic dyes encapsulated in the internal droplets. This approach also decreases the scale of the double droplets up to the nanoscale, which is not possible without silica stabilization. Different formulation and processing parameters were explored in order to optimize the methodology. Physicochemical characterization was performed by dynamic light scattering, encapsulation efficiency measurements, release profiles, and optical and transmission electron microscopies.

13.
ACS Appl Mater Interfaces ; 11(1): 403-416, 2019 Jan 09.
Article in English | MEDLINE | ID: mdl-30541280

ABSTRACT

Noninvasive diagnostic by imaging combined with a contrast agent (CA) is by now the most used technique to get insight into human bodies. X-ray and magnetic resonance imaging (MRI) are widely used technologies providing complementary results. Nowadays, it seems clear that bimodal CAs could be an emerging approach to increase the patient compliance, accessing different imaging modalities with a single CA injection. Owing to versatile designs, targeting properties, and high payload capacity, nanocarriers are considered as a viable solution to reach this goal. In this study, we investigated efficient superparamagnetic iron oxide nanoparticle (SPION)-loaded iodinated nano-emulsions (NEs) as dual modal injectable CAs for X-ray imaging and MRI. The strength of this new CA lies not only in its dual modal contrasting properties and biocompatibility, but also in the simplicity of the nanoparticulate assembling: iodinated oily core was synthesized by the triiodo-benzene group grafting on vitamin E (41.7% of iodine) via esterification, and SPIONs were produced by thermal decomposition during 2, 4, and 6 h to generate SPIONs with different morphologies and magnetic properties. SPIONs with most anisotropic shape and characterized by the highest r2/ r1 ratio once encapsulated into iodinated NE were used for animal experimentation. The in vivo investigation showed an excellent contrast modification because of the presence of the selected NEs, for both imaging techniques explored, that is, MRI and X-ray imaging. This work provides the description and in vivo application of a simple and efficient nanoparticulate system capable of enhancing contrast for both preclinical imaging modalities, MRI, and computed tomography.


Subject(s)
Contrast Media , Iodine , Magnetic Resonance Imaging/methods , Magnetite Nanoparticles , Tomography, X-Ray Computed/methods , Animals , Contrast Media/chemistry , Contrast Media/pharmacokinetics , Contrast Media/pharmacology , Emulsions , HeLa Cells , Humans , Iodine/chemistry , Iodine/pharmacokinetics , Iodine/pharmacology , Magnetite Nanoparticles/chemistry , Magnetite Nanoparticles/therapeutic use , Mice
14.
J Control Release ; 295: 31-49, 2019 02 10.
Article in English | MEDLINE | ID: mdl-30579983

ABSTRACT

Attractive interest on double emulsions comes from their unique morphology, making them general multifunctional carriers able to encapsulate different hydrophilic and lipophilic molecules in the same particle. Over the past century, two different types of methods were followed to prepare double emulsions for pharmaceutics applications, so-called "one-step" and "two-step" processes. The two-step approach, consisting in two different emulsifications successively performed, allows the optimal and more efficient formulations due to simplicity of principle and controllability of the process. In this review, focused on the formulation of double emulsions by two-step process, we recount the historical development of this approach, along with the state-of-the-art, including a discussion on the role of the formulation parameters, surfactants, amphiphilic polymers, interface stabilization, volume fraction, and so forth, on the final formulation stability, morphology and properties as drug delivery system. Discussion was also extended to polymeric microparticles and nanoparticles made by solvent diffusion, on the basis of double emulsions made by two-step process, along with literature review on the impact of different formulation and processing parameters. In addition, the properties of the polymers used in the microparticles matrix (molecular weight, chemical nature) potentially impacting on the ones of the microparticles formed (drug release kinetics, stability, morphology), were also discussed. Finally, the future trends in double emulsions application were addressed, emphasizing some new advances made in the emulsifications method as potentially able to open the range of applications, for example to nanoscale with spontaneous emulsification or low energy microfluidic emulsification.


Subject(s)
Drug Carriers/chemistry , Emulsions/chemistry , Polymers/chemistry , Chemistry, Pharmaceutical/methods , Drug Compounding/methods , Drug Liberation , Hydrophobic and Hydrophilic Interactions , Microfluidic Analytical Techniques/methods , Nanoparticles/chemistry , Pharmaceutical Preparations/administration & dosage , Pharmaceutical Preparations/chemistry
15.
Int J Pharm ; 558: 1-8, 2019 Mar 10.
Article in English | MEDLINE | ID: mdl-30586630

ABSTRACT

We present a two-step process to produce dry-state Ketoprofen-loaded poly(methyl methacrylate) nanoparticles (NPs) with controllable size and tunable drug release profile. A colloidal suspension of drug-loaded nanoparticles was first obtained from a nanoprecipitation process and then transferred into a commercial spray dryer. Three micromixers of different designs and mixing principles (molecular diffusion and impact mixing) were tested. After the first step, highly monomodal NPs in the size range 100 to 210 nm were obtained as seen by the low polydispersity index value (ca. PDI ∼ 0.2) returned by a dynamic light scattering detector. Physicochemical properties, encapsulation efficiency/ratio and drug release kinetics of NPs before and after drying were determined. For similar operating conditions, the best micromixer tested (impact mixing) allowed concluding that the NPs size was not significantly affected by the spray drying while encapsulation parameters and drug release rate were slightly decreased compared to the non spray-dried NPs. A sustained drug release was observed over 6 h and the drug release rate (up to 70%) was found to vary with the size of the NPs which in turn was a function of the flow rate ratio between the polymer solution and the non-solvent solution.


Subject(s)
Drug Carriers/chemistry , Drug Compounding/methods , Ketoprofen/chemistry , Nanoparticles/chemistry , Polymethyl Methacrylate/chemistry , Chemical Precipitation , Delayed-Action Preparations/chemistry , Desiccation , Drug Liberation , Particle Size
16.
ACS Omega ; 3(10): 14333-14340, 2018 Oct 31.
Article in English | MEDLINE | ID: mdl-30411065

ABSTRACT

Understanding the release of drugs and contrast agents from nanocarriers is fundamental in the development of new effective nanomedicines. However, the commonly used method based on dialysis frequently fails to quantify the release of molecules poorly soluble in water, and it is not well-suited for in situ measurements in biological media. Here, we have developed a new methodology for quantifying the release of fluorescent molecules from lipid nanocarriers (LNCs) using fluorescence correlation spectroscopy (FCS). LNCs based on nanoemulsion droplets, encapsulating the hydrophobic Nile red derivative NR668 as a model cargo, were used. Our studies revealed that the standard deviation of fluorescence fluctuations in FCS measurements depends linearly on the dye loading in the nanocarriers, and it is insensitive to the presence of less-bright molecular emissive species in solution. In sharp contrast, classical FCS parameters, such as the number and the brightness of emissive species, are strongly influenced by the fluorescence of molecular species in solution. Therefore, we propose to use the standard deviation of fluorescence fluctuations for the quantitative analysis of dye release from nanocarriers, which is unaffected by the "parasite" fluorescence of the released dyes or the auto-fluorescence of the medium. Using this method, we found that LNCs remain intact in water, whereas in serum medium, they release their content in a temperature-dependent manner. At 37 °C, the release was relatively slow reaching 50% only after 6 h of incubation. The results are corroborated by qualitative observations based on Förster resonance energy transfer between two different encapsulated dyes. The developed method is simple because it is only based on the standard deviation of fluorescence fluctuations and, in principle, can be applied to nanocarriers of different types.

17.
Eur J Pharm Biopharm ; 133: 331-338, 2018 Dec.
Article in English | MEDLINE | ID: mdl-30414990

ABSTRACT

This study investigates the impact of the chemical nature of lipids and additive on the formulation and properties of pH sensitive liposomes. The objective is to understand the respective role of the formulation parameters on the liposome properties in order to optimize the conditions for efficient encapsulation of doxorubicin (DOX). These liposomes should be stable at physiological pH, and disrupt in slightly acidic media such as the tumor microenvironment to release their DOX load. The major challenge for encapsulating DOX in pH sensitive liposomes lies in the fact that this drug is soluble at low pH (when the pH-sensitive liposomes are not stable), but the DOX aqueous solubility decreases in the pH conditions corresponding to the stability of the pH-sensitive liposomes. The study of pH-sensitivity of liposomes was conducted using carboxyfluorescein (CF) encapsulated in high concentration, i.e. quenched, and following the dye dequenching as sensor of the liposome integrity. We studied the impact of (i) the chemical nature of lipids (dioleoyl phosphatidyl ethanolamine (DOPE), palmitoyl-oleoyl phosphatidyl ethanolamine (POPE) and dimyristoyl phosphatidyl ethanolamine (DMPE)) and (ii) the lipid/stabilizing agent ratio (alpha-tocopheryl succinate), on the pH sensitivity of the liposomes. Optimized liposome formulations were then selected for the encapsulation of DOX by an active loading procedure, i.e. driven by a difference in pH inside and outside the liposomes. Numerous experimental conditions were explored, in function of the pH gradient and liposome composition, which allowed identifying critical parameters for the efficient DOX encapsulation in pH-sensitive liposomes.


Subject(s)
Doxorubicin/chemistry , Lipids/chemistry , Liposomes/chemistry , Chemistry, Pharmaceutical/methods , Fluoresceins/chemistry , Hydrogen-Ion Concentration , Phosphatidylethanolamines/chemistry , Solubility/drug effects , Tumor Microenvironment/drug effects , alpha-Tocopherol/chemistry
18.
Crit Rev Ther Drug Carrier Syst ; 35(5): 391-431, 2018.
Article in English | MEDLINE | ID: mdl-30317944

ABSTRACT

In the last two decades, nanoparticle contrast agents have emerged as an essential tool for preclinical imaging and diagnosis. Besides their main advantage, related to their size range inhibiting glomerular filtration, they exhibit excellent X-ray attenuation when fabricated with heavy metal and thus high contrast in tomodensitometry. Another strength of inorganic nanoparticles, making them very adaptable to preclinical imaging applications, is the modularity of their surface chemistry, which is compatible with decoration by ligands and biomolecules. The present review draws a state-of-the art picture of the different inorganic nanoparticles synthesized as X-ray contrast agents. We present the panel of heavy metals and materials used, their X-ray attenuation properties, related applications, potential surface modifications, and in vitro and in vivo behaviors. An important aspect of this review is that the majority of inorganic nanoparticles are based on gold. We summarize the latest technologies for targeting nanoparticles designed to improve imaging techniques and advanced diagnostic methods.


Subject(s)
Contrast Media/administration & dosage , Metal Nanoparticles , Tomography, X-Ray Computed/methods , Animals , Gold/chemistry , Humans , Nanoparticles
19.
Int J Pharm ; 549(1-2): 299-305, 2018 Oct 05.
Article in English | MEDLINE | ID: mdl-30075249

ABSTRACT

This study investigates the formulation of surfactant-free Pickering nano-emulsions able to release a drug at specific pH, in order to enhance its oral bioavailability. The stabilizing nanoparticles composed of magnesium hydroxide, were obtained by nano-precipitation method. The oil-in-water Pickering nano-emulsions stabilized with Mg(OH)2 nanoparticles, and encapsulating a model of hydrophobic drug (ibuprofen) were formulated following a high-energy process, using a sonication probe. The experimental approach explored the impact of all formulation parameters, composition and size of Mg(OH)2 nanoparticles, on the physico-chemical properties of the Pickering nano-emulsions. The system was characterized by DLS and transmission electron microscopy. In addition, Mg(OH)2 has the advantage of being solubilized in an acid medium leading to the destabilization of the nano-emulsion and the release of the active ingredient orally. The acid release study (pH = 1.2) showed cumulative release as a function of initial nanodroplet loading and saturation concentration. In basic media (pH = 6.8), we found a significant release of ibuprofen from the nano-emulsions that already had saturation in an acid medium. These nano-emulsions can not only protect patients from the side effects of acid medicines through the basic properties of hydroxides but also can contribute to the increase of the bioavailability of these drugs. In addition, once in the stomach pH is increased by hydroxides and promotes the release of active ingredients such as ibuprofen whose solubility is strongly influenced by pH.


Subject(s)
Cyclooxygenase Inhibitors/chemistry , Drug Carriers , Ibuprofen/chemistry , Magnesium Oxide/chemistry , Nanoparticles , Nanotechnology , Technology, Pharmaceutical/methods , Administration, Oral , Cyclooxygenase Inhibitors/administration & dosage , Delayed-Action Preparations , Drug Compounding , Drug Liberation , Drug Stability , Emulsions , Hydrogen-Ion Concentration , Hydrophobic and Hydrophilic Interactions , Ibuprofen/administration & dosage , Kinetics , Solubility
20.
Langmuir ; 34(5): 1981-1991, 2018 02 06.
Article in English | MEDLINE | ID: mdl-29334739

ABSTRACT

In this paper, superparamagnetic iron oxide nanoparticles (SPIONs, around 6 nm) encapsulated in poly(methyl methacrylate) nanoparticles (PMMA NPs) with controlled sizes ranging from 100 to 200 nm have been successfully produced. The hybrid polymeric NPs were prepared following two different methods: (1) nanoprecipitation and (2) nanoemulsification-evaporation. These two methods were implemented in two different microprocesses based on the use of an impact jet micromixer and an elongational-flow microemulsifier. SPIONs-loaded PMMA NPs synthesized by the two methods presented completely different physicochemical properties. The polymeric NPs prepared with the micromixer-assisted nanoprecipitation method showed a heterogeneous dispersion of SPIONs inside the polymer matrix, an encapsulation efficiency close to 100 wt %, and an irregular shape. In contrast, the polymeric NPs prepared with the microfluidic-assisted nanoemulsification-evaporation method showed a homogeneous dispersion, an almost complete encapsulation, and a spherical shape. The properties of the polymeric NPs have been characterized by dynamic light scattering, thermogravimetric analysis, and transmission electron microscope. In vitro cytotoxicity assays were also performed on the nanohybrids and pure PMMA NPs.

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