Beyond the danger signal: RNA aggregates orchestrate immunotherapy.

Mendez-Gomez et al. recently demonstrated the transformative potential of RNA-lipid particle aggregates (RNA-LPAs) in immunotherapy. By reprogramming the tumor microenvironment (TME) and potentiating antitumor immunity, RNA-LPAs target primary tumors and elicit robust systemic immunity. This innovative platform holds promise for translating preclinical success into tangible clinical benefits.

Nano-Spray-Dried Levocetirizine Dihydrochloride with Mucoadhesive Carriers and Cyclodextrins for Nasal Administration.

Antihistamines such as levocetirizine dihydrochloride (LC) are commercially used in oral tablets and oral drops to reduce allergic symptoms. In this study, LC was nano-spray-dried using three mucoadhesive polymers and four cyclodextrin species to form composite powders for nasal administration. The product was composed of hydroxypropyl methylcellulose polymer, including LC as a zwitterion, after neutralization by NaOH, and XRD investigations verified its amorphous state. This and a sulfobutylated-beta-cyclodextrin sodium salt-containing sample showed crystal peaks due to NaCl content as products of the neutralization reaction in the solutions before drying. The average particle size of the spherical microparticles was between 2.42 and 3.44 µm, except for those containing a polyvinyl alcohol excipient, which were characterized by a medium diameter of 29.80 µm. The drug was completely and immediately liberated from all the samples at pH 5.6 and 32 °C; i.e., the carriers did not change the good dissolution behavior of LC. A permeability test was carried out by dipping the synthetic cellulose ester membrane in isopropyl myristate using modified horizontal diffusion cells. The spray-dried powder with ß-cyclodextrin showed the highest permeability (188.37 µg/cm2/h), as this additive was the least hydrophilic. Products prepared with other cyclodextrins (randomly methylated-beta-cyclodextrin, sulfobutylated-beta-cyclodextrin sodium salt and (hydroxypropyl)-beta-cyclodextrin) showed similar or slightly higher penetration abilities than LC. Other polymer excipients resulted in lower penetration of the active agent than the pure LC.

Topical Formulation of Nano Spray-Dried Levocetirizine Dihydrochloride against Allergic Edema.

Levocetirizine dihydrochloride active ingredient was microencapsulated using nano spray-drying technology for preparing microparticles containing topical gel against edema. Hydroxyl propyl methyl cellulose (HPMC) was used as a carrier polymer during spray drying. The active ingredient content of the nano spray-dried products was 52.81% (w/w) and 51.33% (w/w) for ex vivo and in vivo experiments, respectively, and the average particle size was 2.6 µm. X-ray diffraction analysis indicated an amorphous state of the active ingredient embedded in the amorphous matrix of the polymer. Dermal oil gels composed of Miglyol 812 gelated by Dermofeel viscolid included 5% (w/w) (for ex vivo) and 10% (w/w) (for in vivo) active ingredient without or with 0.05% (w/w) menthol penetration enhancer. Qualitative ex vivo penetration studies using a confocal Raman microscopic correlation mapping were executed on human abdominal skin. The results showed that the active ingredient was enriched in the epidermis and upper dermis layer of the skin using oleogel loaded with the nano spray-dried drug-HPMC composite. Menthol addition to the oleogel resulted in the concentration of levocetirizine in the dermis. In vivo tests were performed on a mouse model of croton oil-induced ear edema. Negative control and Fenistil-treated groups were compared using the prepared oil gels with and without menthol. Without penetration enhancer, 20 µL of our oil gel loaded with nano spray-dried levocetirizine dihydrochloride composite showed similar effectiveness to the same volume of Fenistil gel, while 5 µL menthol containing sample was sufficient to eliminate the skin irritation similarly to 20 µL Fenistil.

Immobilization of Metronidazole on Mesoporous Silica Materials.

Metronidazole (MTZ) is a widely used drug, but due to its many side effects, there is a growing trend today to use a minimum dose while maintaining high efficacy. One way to meet this demand is to reduce the size of the drug particles. A relatively new method of size reduction is attaching the drug molecules to a mesoporous carrier. In this paper, we studied the fixation of MTZ molecules on mesoporous silica carriers. The drug was immobilized on two mesoporous silica materials (Syloid, SBA-15) with the use of a variety of immersion techniques and solvents. The immobilized drug was subjected to physicochemical examinations (e.g., SEM, XPS, XRD, nitrogen uptake, DSC) and dissolution studies. A significantly higher immobilization was attained on SBA-15 than on a Syloid carrier. Among the processing parameters, the type of MTZ solvent had the highest influence on immobilization. Ultrasonic agitation had a lower but still significant impact, while the concentration of MTZ in the solution made no difference. Under optimal conditions, with the application of an ethyl acetate solution, the surface coverage on SBA-15 reached as much as 91%. The immobilized MTZ exhibited a ca. 10% faster dissolution rate as compared to the pure micron-sized drug particles.

Halochromic Behavior and Anticancer Effect of New Synthetic Anthocyanidins Complexed with ß-Cyclodextrin Derivatives.

Anthocyanidins, the aglycons of anthocyanins, are known, beyond their function in plants, also as compounds with a wide range of biological and pharmacological activities, including cytostatic effect against various cancer cells. The nature and position of the substituents in the flavylium cation is essential for such biological properties, as well as the equilibrium between the multistate of the different chemical species that are generated by the flavylium cation, including quinoidal base, hemiketal, and cis- and trans-chalcones. In this work, eight new flavylium derivatives were synthesized, characterized for confirmation of the structure by FT-IR and 2D-NMR, and investigated in vitro as possible cytostatic compounds against HCT116 and HepG2 cancer cells. The most active two compounds were explored for their halochromic properties that can influence the biological activity and subjected to molecular encapsulation in ß-cyclodextrin derivatives in order to increase their solubility in water and bioavailability. The anticancer effect was influenced by the position (6-, 7-, or 8-) of the methoxy group in the ß-ring of the methoxy-4'-hydroxy-3'-methoxyflavylium cation, while the study of the halochromic properties revealed the important role played by the chalcone species of the pH-dependent multistate in both the uncomplexed and inclusion complex forms of these anthocyanidins.

Sustainable Stabilizer-Free Nanoparticle Formulations of Valsartan Using Eudragit® RLPO.

The bioavailability of the antihypertensive drug valsartan can be enhanced by various microencapsulation methods. In the present investigation, valsartan-loaded polymeric nanoparticles were manufactured from Eudragit® RLPO using an emulsion-solvent evaporation method. Polyvinyl alcohol (PVA) was found to be a suitable stabilizer for the nanoparticles, resulting in a monodisperse colloid system ranging in size between 148 nm and 162 nm. Additionally, a high encapsulation efficiency (96.4%) was observed. However, due to the quaternary ammonium groups of Eudragit® RLPO, the stabilization of the dispersion could be achieved in the absence of PVA as well. The nanoparticles were reduced in size (by 22%) and exhibited similar encapsulation efficiencies (96.4%). This more cost-effective and sustainable production method reduces the use of excipients and their expected emission into the environment. The drug release from valsartan-loaded nanoparticles was evaluated in a two-stage biorelevant dissolution set-up, leading to the rapid dissolution of valsartan in a simulated intestinal medium. In silico simulations using a model validated previously indicate a potential dose reduction of 60-70% compared to existing drug products. This further reduces the expected emission of the ecotoxic compound into the environment.

Encapsulation of Metronidazole in Biocompatible Macrocycles and Structural Characterization of Its Nano Spray-Dried Nanostructured Composite.

Due to the great potential of biocompatible cucurbit[7]uril (CB7) and 4-sulfonatocalix[4]arene (SCX4) macrocycles in drug delivery, the confinement of the pharmaceutically important metronidazole as an ionizable model drug has been systematically studied in these cavitands. Absorption and fluorescence spectroscopic measurements gave 1.9 × 105 M-1 and 1.0 × 104 M-1 as the association constants of the protonated metronidazole inclusion in CB7 and SCX4, whereas the unprotonated guests had values more than one order of magnitude lower, respectively. The preferential binding of the protonated metronidazole resulted in 1.91 pH unit pKa diminution upon encapsulation in CB7, but the complexation with SCX4 led to a pKa decrease of only 0.82 pH unit. The produced protonated metronidazole-SCX4 complex induced nanoparticle formation with protonated chitosan by supramolecular crosslinking of the polysaccharide chains. The properties of the aqueous nanoparticle solutions and the micron-sized solid composite produced therefrom by nano spray drying were unraveled. The results of the present work may find application in the rational design of tailor-made self-assembled drug carrier systems.

Co-Entrapment of Sorafenib and Cisplatin Drugs and iRGD Tumour Homing Peptide by Poly[ε-caprolactone-co-(12-hydroxystearate)] Copolymer.

The drug-loaded nanocarriers have overcome various challenges compared with the pure chemotherapeutic drug, such as limited bioavailability, multiple drug resistance, poor patient compliance, and adverse drug reactions, offering advantages such as protection from degradation in the blood stream, better drug solubility, and improved drug stability. One promising group of controlled and targeted drug delivery systems is polymer-based nanoparticles that can sustain the release of the active agent by diffusion and their degradation. Sorafenib is the only drug that can prolong the life of patients suffering from hepatocellular carcinoma. Cisplatin remains one of the most widely used broad-spectrum anticancer drugs for the treatment of a variety of solid tumours. Nanoformulations can exert a synergistic effect by entrapping two drugs with different modes of action, such as sorafenib and cisplatin. In our study, polymeric nanoparticles were prepared with a good production yield by an improved double emulsion solvent evaporation method using the copolymer of 12-hydroxystearic acid with ε-caprolactone (12CL), a biocatalytically synthesised biocompatible and biodegradable carrier, for the co-entrapment of sorafenib and cisplatin in nanotherapeutics. A bovine serum albumin (BSA) model compound was used to increase the cisplatin incorporation; then, it was successfully substituted by a iRGD tumour penetrating peptide that might provide a targeting function of the nanoparticles.

Poly(3-Hydroxybutyrate)-Based Nanoparticles for Sorafenib and Doxorubicin Anticancer Drug Delivery.

Dual drug-loaded nanotherapeutics can play an important role against the drug resistance and side effects of the single drugs. Doxorubicin and sorafenib were efficiently co-encapsulated by tailor-made poly([R,S]-3-hydroxybutyrate) (PHB) using an emulsion-solvent evaporation method. Subsequent poly(ethylene glycol) (PEG) conjugation onto nanoparticles was applied to make the nanocarriers stealth and to improve their drug release characteristics. Monodisperse PHB-sorafenib-doxorubicin nanoparticles had an average size of 199.3 nm, which was increased to 250.5 nm after PEGylation. The nanoparticle yield and encapsulation efficiencies of drugs decreased slightly in consequence of PEG conjugation. The drug release of the doxorubicin was beneficial, since it was liberated faster in a tumor-specific acidic environment than in blood plasma. The PEG attachment decelerated the release of both the doxorubicin and the sorafenib, however, the release of the latter drug remained still significantly faster with increased initial burst compared to doxorubicin. Nevertheless, the PEG-PHB copolymer showed more beneficial drug release kinetics in vitro in comparison with our recently developed PEGylated poly(lactic-co-glycolic acid) nanoparticles loaded with the same drugs.

Sustained in vitro interferon-beta release and in vivo toxicity of PLGA and PEG-PLGA nanoparticles.

Interferon-beta-1a (IFN-ß-1a) can diminish the symptoms of relapsing-remitting multiple sclerosis. Herein, we prepared sustained drug delivery IFN-ß-1a-loaded nanoparticles by a double emulsion solvent evaporation method. Bovine serum albumin (BSA) model drug was used to optimize the preparation of nanoparticles composed of four types of poly(lactic-co-glycolic acid) (PLGA) polymers and two pegylated PLGA (PEG-PLGA) polymers. Via optimization, selected PLGA and PEG-PLGA polymers were able to entrap IFN-ß-1a with high encapsulation efficiency (>95%) and low size (145 nm and 163 nm, respectively). In vitro release kinetics of BSA and IFN-ß showed similar tendency for PLGA and PEG-PLGA nanoparticles, respectively. Although the drug loaded nanoparticles did not show toxicity in hepatocyte cells, mild toxic effects such as pale kidney and pyelectasis were observed in the in vivo studies.

Preparation and in vitro characterization of valsartan-loaded ethyl cellulose and poly(methyl methacrylate) nanoparticles.

Valsartan is an antihypertensive drug used primarily orally, however, due to its hydrophobic nature it has got low bio-availability thus requiring higher dosage/frequency and causing more side effects. The aim of our work was to prepare valsartan-loaded nanoparticles by using ethyl cellulose and poly(methyl methacrylate) polymers which can be administered orally and to investigate the preparation conditions and their significance as potential drug carriers for valsartan delivery by in vitro release studies. Ethyl cellulose and poly(methyl methacrylate) polymers were used for the preparation of nanoparticles by single emulsion-solvent evaporation technique. The formation of drug-loaded nanoparticles was designed by experimental design for size and encapsulation efficiency, in addition the prepared nanosuspensions were nano spray dried in order to gain a powder form that is easy to handle and store. Both of the nano spray dried formulations had an amorphous structure in contrast to the pure drug according to differential scanning calorimetry and X-ray diffraction analysis, which can be advantageous in drug absorption. The originally processed ethyl cellulose-valsartan nanoparticles increased the solubility of the drug in the model intestinal medium, while poly(methyl methacrylate)-valsartan nanoparticles enabled substantially prolonged drug release. The release kinetics of both types of nanoparticles could be described by the Weibull model.

Theranostic Sorafenib-Loaded Polymeric Nanocarriers Manufactured by Enhanced Gadolinium Conjugation Techniques.

: Today, efficient delivery of sorafenib to hepatocellular carcinoma remains a challenge for current drug formulation strategies. Incorporating the lipophilic molecule into biocompatible and biodegradable theranostic nanocarriers has great potential for improving the efficacy and safety of cancer therapy. In the present study, three different technologies for the encapsulation of sorafenib into poly(d,l-lactide-co-glycolide) and polyethylene glycol-poly(d,l-lactide-co-glycolide) copolymers were compared. The particles ranged in size between 220 and 240 nm, with encapsulation efficiencies from 76.1 ± 1.7% to 69.1 ± 10.1%. A remarkable maximum drug load of approximately 9.0% was achieved. Finally, a gadolinium complex was covalently attached to the nanoparticle surface, transforming the nanospheres into theranostic devices, allowing their localization using magnetic resonance imaging. The manufacture of sorafenib-loaded nanoparticles alongside the functionalization of the particle surface with gadolinium complexes resulted in a highly efficacious nanodelivery system which exhibited a strong magnetic resonance imaging signal, optimal stability features, and a sustained release profile.

Preparation of cubic-shaped sorafenib-loaded nanocomposite using well-defined poly(vinyl alcohol alt-propenylene) copolymer.

Vinyl alcohol (VA) copolymers having fine tunable polarities are emerging materials in drug delivery applications. VA copolymers rendering well-defined molecular architecture (C/OH ratio = 2, 4, 5 and 8) were used as carriers for model drug compound, fluorescein, which exhibited significantly different release characteristics depending on the polarity of the polymers. Based on the preliminary drug release tests the well-defined VA copolymer having C/OH = 5 ratio, poly(vinyl alcohol alt-propenylene) copolymer (PVA-5) was selected for nanocomposite synthesis. Sorafenib anticancer drug was embedded into PVA-5 (C/OH = 5 ratio) nanoparticles by nanoprecipitation resulting in nanoparticles exhibiting unusual cubic shape. The sorafenib-loaded nanocomposites showed continuous release during a day and concentration-dependant cytotoxicity on HT-29 cancer cells. This might be interpreted by the sustained release of the drug.

Stimulating brain recovery after stroke using theranostic albumin nanocarriers loaded with nerve growth factor in combination therapy.

For many years, delivering drug molecules across the blood brain barrier has been a major challenge. The neuropeptide nerve growth factor is involved in the regulation of growth and differentiation of cholinergic neurons and holds great potential in the treatment of stroke. However, as with many other compounds, the biomolecule is not able to enter the central nervous system. In the present study, nerve growth factor and ultra-small particles of iron oxide were co-encapsulated into a chemically crosslinked albumin nanocarrier matrix which was modified on the surface with apolipoprotein E. These biodegradable nanoparticles with a size of 212 ±â€¯1 nm exhibited monodisperse size distribution and low toxicity. They delivered NGF through an artificial blood brain barrier and were able to induce neurite outgrowth in PC12 cells in vitro. In an animal model of stroke, the infarct size was significantly reduced compared to the vehicle control. The combination therapy of NGF and the small-molecular MEK inhibitor U0126 showed a slight but not significant difference compared to U0126 alone. However, further in vivo evidence suggests that successful delivery of the neuropeptide is possible as well as the synergism between those two treatments.

Dual Drug Delivery of Sorafenib and Doxorubicin from PLGA and PEG-PLGA Polymeric Nanoparticles.

Combinatorial drug delivery is a way of advanced cancer treatment that at present represents a challenge for researchers. Here, we report the efficient entrapment of two clinically used single-agent drugs, doxorubicin and sorafenib, against hepatocellular carcinoma. Biocompatible and biodegradable polymeric nanoparticles provide a promising approach for controlled drug release. In this study, doxorubicin and sorafenib with completely different chemical characteristics were simultaneously entrapped by the same polymeric carrier, namely poly(d,l-lactide-co-glycolide) (PLGA) and polyethylene glycol-poly(d,l-lactide-co-glycolide) (PEG-PLGA), respectively, using the double emulsion solvent evaporation method. The typical mean diameters of the nanopharmaceuticals were 142 and 177 nm, respectively. The PLGA and PEG-PLGA polymers encapsulated doxorubicin with efficiencies of 52% and 69%, respectively, while these values for sorafenib were 55% and 88%, respectively. Sustained drug delivery under biorelevant conditions was found for doxorubicin, while sorafenib was released quickly from the PLGA-doxorubicin-sorafenib and PEG-PLGA-doxorubicin-sorafenib nanotherapeutics.

2,4-Dichlorophenol Enzymatic Removal and Its Kinetic Study Using Horseradish Peroxidase Crosslinked to Nano Spray-Dried Poly(Lactic-Co-Glycolic Acid) Fine Particles.

Horseradish peroxidase (HRP) catalyzes the oxidation of aromatic compounds by hydrogen peroxide via insoluble polymer formation, which can be precipitated from the wastewater. For HRP immobilization, poly(lactic-co-glycolic acid) (PLGA) fine carrier supports were produced by using the Nano Spray Dryer B-90. Immobilized HRP was used to remove the persistent 2,4-dichlorophenol from model wastewater. Both extracted (9-16 U/g) and purified HRP (11-25 U/g) retained their activity to a high extent after crosslinking to the PLGA particles. The immobilized enzyme activity was substantially higher in both the acidic and the alkaline pH regions compared with the free enzyme. Optimally, 98% of the 2,4-dichlorophenol could be eliminated using immobilized HRP due to catalytic removal and partly to adsorption on the carrier supports. Immobilized enzyme kinetics for 2,4-dichlorophenol elimination was studied for the first time, and it could be concluded that competitive product inhibition took place.

In vitro IFN-α release from IFN-α- and pegylated IFN-α-loaded poly(lactic-co-glycolic acid) and pegylated poly(lactic-co-glycolic acid) nanoparticles.

AIM: Interferon alpha (IFN-α) controlled release of nanoparticles was investigated under in vitro conditions. MATERIALS & METHODS: IFN-α and pegylated IFN-α (PEG-IFN-α) were encapsulated by poly(lactic-co-glycolic acid) (PLGA) and pegylated PLGA (PEG-PLGA) copolymers using double emulsion solvent evaporation method. RESULTS: The size of resulting four nanoparticles (IFN-α in poly(lactic-co-glycolic acids), IFN-α in poly(lactic-co-glycolic acid)-polyethylene glycol, PEG-IFN-α in poly(lactic-co-glycolic acids) and PEG-IFN-α in poly(lactic-co-glycolic acid)-polyethylene glycol) was below 130 nm diameter. IFN-α encapsulation efficiency of the nanoparticles was between 78 and 91%. CONCLUSION: The in vitro drug release studies conducted in phosphate-buffered saline and human plasma highlighted the role of incubation medium on the IFN release from the nanoparticles. The PEG-IFN-α in poly(lactic-co-glycolic acid)-polyethylene glycol was the most promising nanoparticle among the four formulations because of its remarkably constant release in both phosphate-buffered saline and plasma.

Surface modification of HSA containing magnetic PLGA nanoparticles by poloxamer to decrease plasma protein adsorption.

Lifetime prolongation for hydrophobic drug carriers has been the focus of interest for many years. Poloxamer (Pluronic F68, PF68) has been employed in this study for modifying the surface of magnetic poly(d,l-lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) loaded with human serum albumin (HSA) model drug. Surface characteristics of untreated and PF68 treated NPs were analyzed by size, zeta potential and electrophoretic mobility studies. UV-vis spectroscopic analysis, isothermal titration calorimetry (ITC) and dynamic light scattering methods were used to investigate serum protein (bovine serum albumin, BSA) adsorption. Results showed the successful surface attachment of PF68. Among different concentrations (0.1-1%, wt/vol) of PF68 studied, 0.5% was found to be the most useful, since a higher concentration can issue in micelle formation. 50% less BSA tended to be adsorbed on the treated NPs in comparison to the untreated ones.

Co-encapsulation of human serum albumin and superparamagnetic iron oxide in PLGA nanoparticles: part I. Effect of process variables on the mean size.

PLGA (poly d,l-lactic-co-glycolic acid) nanoparticles (NPs) encapsulating magnetite nanoparticles (MNPs) along with a model drug human serum albumin (HSA) were prepared by double emulsion solvent evaporation method. This Part I will focus on size and size distribution of prepared NPs, whereas encapsulation efficiency will be discussed in Part II. It was found that mean hydrodynamic particle size was influenced by five important process variables. To explore their effects, a five-factorial, three-level experimental design and statistical analysis were carried out using STATISTICA® software. Effect of process variables on the mean size of nanoparticles was investigated and finally conditions to minimize size of NPs were proposed. GAMS™/MINOS software was used for optimization. The mean hydrodynamic size of nanoparticles ranged from 115 to 329 nm depending on the process conditions. Smallest possible mean particle size can be achieved by using low polymer concentration and high dispersion energy (enough sonication time) along with small aqueous/organic volume ratio.

Co-encapsulation of human serum albumin and superparamagnetic iron oxide in PLGA nanoparticles: part II. Effect of process variables on protein model drug encapsulation efficiency.

This study investigates encapsulation efficiency of model drug, encapsulated by magnetic poly d,l-lactic-co-glycolic acid (PLGA) nanoparticles (NPs). This is the following part of our preceding paper, which is referred in this paper as Part I. Magnetic nanoparticles and model drug human serum albumin (HSA)-loaded PLGA NPs were prepared by the double emulsion solvent evaporation method. Among five important process variables, concentration of PLGA and concentration of HSA in the inner aqueous phase along with their cross-effect had the strongest influence on the encapsulation efficiency. Encapsulation efficiency of nanoparticles ranged from 18% to 97% depending on the process conditions. Higher encapsulation efficiencies can be achieved by using low HSA and high PLGA concentrations. The optimization process, carried out by exact mathematical tools using GAMSTM/MINOS software makes it easier to find out optimum process conditions to achieve comparatively high encapsulation efficiency (e.g. 92.3%) for relatively small-sized PLGA NPs (e.g. 155 nm).