A Novel PAA Derivative with Enhanced Drug Efficacy in Pancreatic Cancer Cell Lines.

Nanoparticles have been shown to be effective drug carriers in cancer therapy. Pancreatic cancer forms dense tumours which are often resistant to drug molecules. In order to overcome such multidrug resistance, new drug entities, novel delivery systems and combination therapy strategies are being explored. In this paper, we report the design and synthesis of a poly(allylamine)-based amphiphile modified with hydrophobic naphthalimido pendant groups. Bisnaphthalimide compounds have been shown to possess anticancer activity. The potential of this polymer to encapsulate, solubilize and enhance drug (5-fluorouricil and bis-(naphthalimidopropyl)-diaminooctane) cytotoxicity in BxPC-3 cells was evaluated. Our studies showed that the insoluble drugs could be formulated up to 4.3 mg mL-1 and 2.4 mg mL-1 inside the amphiphiles, respectively. Additionally, the novel poly(allylamine)-naphthalimide carrier resulted in an amplification of cytotoxic effect with drug treatment after 24 h, and was capable of reduction of 50% cell population at concentrations as low as 3 µg mL-1.

Dual-Laboratory Validation of a Method for the Determination of Fructans in Infant Formula and Adult Nutritionals: First Action 2016.14.

Until recently, only two AOAC Official MethodsSM have been available for the analysis of fructans: Method 997.08 and Method 999.03. Both are based on the analysis of the fructan component monosaccharides (glucose and fructose) after hydrolysis. The two methods have some limitations due to the strategies used for removing background interferences (such as from sucrose, α-glucooligosaccharides, and free sugars). The method described in this paper has been developed to overcome those limitations. The method is largely based on Method 999.03 and uses combined enzymatic and SPE steps to remove the interfering components without impacting the final analytical result. The method has been validated in two laboratories on infant formula and adult nutritionals. Recoveries were in the range of 86-119%, with most being in the range of 91-104%. RSDr values were in the range of 0.7-2.6%, with one exception when the fructan concentration was close to the LOQ, resulting in an RSDr of 8.9%. The performance is generally within the requirements outlined in the AOAC Standard Method Performance Requirements (SMPR® 2014.002), which specifies recoveries in the range of 90-110% and RSDr values below 6%.

Development and validation of HPLC method with fluorometric detection for quantification of bisnaphthalimidopropyldiaminooctane in animal tissues following administration in polymeric nanoparticles.

A simple, sensitive and specific high-performance liquid chromatography method for the quantification of bisnaphthalimidopropyldiaminooctane (BNIPDaoct), a potent anti-Leishmania compound, incorporated into poly(d,l-lactide-co-glycolic acid) (PLGA) nanoparticles was developed and validated toward bioanalysis application. Biological tissue extracts were injected into a reversed-phase monolithic column coupled to a fluorimetric detector (λexc=234nm, λem=394nm), using isocratic elution with aqueous buffer (acetic acid/acetate 0.10M, pH 4.5, 0.010M octanesulfonic acid) and acetonitrile, 60:40 (v/v) at a flow rate of 1.5mLmin(-1). The run time was 6min, with a BNIPDaoct retention time of 3.3min. Calibration curves were linear for BNIPDaoct concentrations ranging from 0.002 to 0.100µM. Matrix effects were observed and calibration curves were performed using the different organ (spleen, liver, kidney, heart and lung) extracts. The method was found to be specific, accurate (97.3-106.8% of nominal values) and precise for intra-day (RSD<1.9%) and inter-day assays (RSD<7.2%) in all matrices. Stability studies showed that BNIPDaoct was stable in all matrices after standing for 24h at room temperature (20°C) or in the autosampler, and after three freeze-thaw cycles. Mean recoveries of BNIPDaoct spiked in mice organs were >88.4%. The LOD and LOQ for biological matrices were ≤0.8 and ≤1.8nM, respectively, corresponding to values ≤4 and ≤9nmolg(-1) in mice organs. The method developed was successfully applied to biodistribution assessment following intravenous administration of BNIPDaoct in solution or incorporated in PLGA nanoparticles.

Characterization and evaluation of BNIPDaoct-loaded PLGA nanoparticles for visceral leishmaniasis: in vitro and in vivo studies.

OBJECTIVE: To overcome the limitation of bisnaphthalimidopropyldiaaminooctane (BNIPDaoct) low physiological solubility and potentially increase its efficiency against visceral leishmaniasis (VL), a delivery system based on poly(d,l-lactide-co-glycolide) (PLGA) nanoparticles was developed. MATERIALS & METHODS: BNIPDaoct-PLGA nanoparticles were prepared by nanoprecipitation and characterized. Anti-Leishmania activity was evaluated using in vitro and in vivo VL infection models. RESULTS: BNIPDaoct-PLGA nanoparticles were successfully produced and were sized at 156.0 ± 2.8 nm with an encapsulation efficiency of approximately 85%. The PLGA nanoparticles reduced BNIPDaoct cellular toxicity, retained its in vitro anti-leishmanial activity and led to a significant reduction (∼80%) in the parasite burden in the infected mice spleen when compared with the free drug or amphotericin B. In the liver the effect was less pronounced, with a 30-50% reduction observed between the nanoformulation and the BNIPDaoct per se or the amphotericin B, respectively. CONCLUSION: PLGA nanoparticles provide controlled and effective delivery of BNIPDaoct for treatment of VL.

The use of nano polymeric self-assemblies based on novel amphiphilic polymers for oral hydrophobic drug delivery.

PURPOSE: To investigate the use of nano self-assemblies formed by polyallylamine (PAA) modified with 5 or 10% mole fluorenylmethoxy carbonyl (Fmoc(5)/(10)), dimethylamino-1-naphthalenesulfonyl (Dansyl(5)/(10)) and 5% mole cholesteryl group (Ch(5)) for oral hydrophobic drug delivery. METHODS: Propofol, griseofulvin and prednisolone were loaded into amphiphilic PAAs. Particle size and morphology of drug-loaded self-assemblies were determined using photon correlation spectroscopy and transmission electron microscopy. Solubilising capacity, in vitro drug release and formulation stability were analysed by HPLC, and in vitro biocompatibility studies (haemolysis and cytotoxicity) were carried out on bovine erythrocytes and Caco-2 cells, respectively. Dansyl(10) and Ch(5) griseofulvin formulations were administered intra-gastrically to rats, and drug plasma levels were analysed by HPLC. RESULTS: Drug-encapsulated self-assemblies typically have hydrodynamic size of 300-400 nm. Dansyl(10) exhibited universal drug solubiliser property and had significantly improved prednisolone, griseofulvin and propofol solubility by 145, 557 and 224-fold, respectively. Fmoc polymers resulted in modest drug solubility improvement. These polymers were non-haemolytic, did not enhance cytotoxicity compared to unmodified PAA, and demonstrated significant increase in griseofulvin plasma concentration compared to griseofulvin in water after oral administration. CONCLUSIONS: Ch(5) and Dansyl(10) showed promising potential as nano-carriers for oral hydrophobic drug delivery.

Anti-leishmanial activity of the bisnaphthalimidopropyl derivatives.

Bisnaphthalimidopropyl (BNIP) derivatives were recently identified as inhibitors of the Leishmania Silent Information Regulator 2 (SIR2) NAD(+)-dependent deacetylase. In this report we have for the first time, determined the potential of these compounds to treat visceral leishmaniasis using BALB/c mice chronically infected with Leishmania infantum as a model. These experiments led to the identification of BNIPdiaminooctane (BNIPDaoct) as an effective compound able to induce significant reduction of the parasite load in the spleen and in the liver. Indeed, at a dose of 1mg/kg, BNIPDaoct was more effective to treat leishmaniasis in a short course treatment (3 or 6 drug administrations) than the standard amphotericin B. Moreover, no indications of hematological toxicity were detected as evaluated by the hemoglobin, hematocrit, white and red blood cell counts, hence making BNIPDaoct a potential therapeutic agent against leishmaniasis.

Nano self-assemblies based on cholate grafted poly-L-lysine enhanced the solubility of sterol-like drugs.

The physicochemical compatibility between amphiphilic polymers and hydrophobic drugs has been recognized as an important issue for improving the drug solubilisation in polymeric micelle formulations. In this work, poly-L-lysine (PLL) grafted by cholate pendants as the only hydrophobic moiety were synthesized in order to facilitate the solubilisation of sterol drugs. Results showed that micelles formed by cholate grafted PLL encapsulated significantly higher level of prednisolone and estradiol than palmitoylated PLL micelles, whereas the solubilisation capacity of non-sterol drug (griseofulvin) is inefficient for both polymers. This suggests that higher drug-polymer incorporation can be achieved by the inclusion of hydrophobic moieties with similar architecture as the drugs, i.e. 'drug-like' functional groups, which will be useful for the future design of colloidal systems for the encapsulation of specific drug.

In Vitro and In Vivo Antimalarial Activity Assays of Seeds from Balanites aegyptiaca: Compounds of the Extract Show Growth Inhibition and Activity against Plasmodial Aminopeptidase.

Balanites aegyptiaca (Balanitaceae) is a widely grown desert plant with multiuse potential. In the present paper, a crude extract from B. aegyptiaca seeds equivalent to a ratio of 1 : 2000 seeds to the extract was screened for antiplasmodial activity. The determined IC(50) value for the chloroquine-susceptible Plasmodium falciparum NF54 strain was 68.26 µg/µL ± 3.5. Analysis of the extract by gas chromatography-mass spectrometry detected 6-phenyl-2(H)-1,2,4-triazin-5-one oxime, an inhibitor of the parasitic M18 Aspartyl Aminopeptidase as one of the compounds which is responsible for the in vitro antiplasmodial activity. The crude plant extract had a K(i) of 2.35 µg/µL and showed a dose-dependent response. After depletion of the compound, a significantly lower inhibition was determined with a K(i) of 4.8 µg/µL. Moreover, two phenolic compounds, that is, 2,6-di-tert-butyl-phenol and 2,4-di-tert-butyl-phenol, with determined IC(50) values of 50.29 µM ± 3 and 47.82 µM ± 2.5, respectively, were detected. These compounds may contribute to the in vitro antimalarial activity due to their antioxidative properties. In an in vivo experiment, treatment of BALB/c mice with the aqueous Balanite extract did not lead to eradication of the parasites, although a reduced parasitemia at day 12 p.i. was observed.

Synthesis and biological activities of bisnaphthalimido polyamines derivatives: cytotoxicity, DNA binding, DNA damage and drug localization in breast cancer MCF 7 cells.

New bisoxynaphthalimidopolyamines (BNIPOPut, BNIPOSpd and BNIPOSpm) were synthesized. Their cytotoxic properties were evaluated against breast cancer MCF 7 cells and compared with bisnaphthalimidopolyamines BNIPSpd and BNIPSpm. Among the bisoxynaphthalimido polyamines, BNIPOSpm and BNIPOSpd exhibited cytotoxic activity with an IC50 f 29.55 and 27.22 microM, respectively, while BNIPOPut failed to exert significant cytotoxicity after 48-h drug exposure. DNA binding was determined by midpoint of thermal denaturation (Tm) measurement, ethidium bromide displacement and DNA gel mobility. Both BNIPOSpm and BNIPOSpd exhibited strong binding affinities with DNA. BNIPOPut had the least effect. The results were compared with other cytotoxic bisnaphthalimido compounds (BNIPSpm and BNIPSpd) previously reported by us. Using the single cell gel electrophoresis assay, it was found that BNIPSpm and BNIPSpd caused substantial DNA damage to MCF 7 treated cells while BNIPOSpm showed no significant effect over a range of drug concentrations after 4-h drug exposure. However, after 12-h drug exposure, BNIPOSpm had induced significant DNA damage similar to that of BNIPSpm (after 4-h drug exposure). Fluorescence microscopic analysis revealed that at 1 microM drug concentration and after 6-h drug exposure, both BNIPSpm and BNIPSpd were located within the cell while the presence of BNIPOSpm, was not observed. Therefore, we conclude that BNIPSpd, BNIPSpm and BNIPOSpm induce DNA damage consistent with their rate of uptake into the cells.