Amorphous Drug Nanoparticles for Inhalation Therapy of Multidrug-Resistant Tuberculosis.

Tuberculosis (TB) is one of the most prevalent infectious diseases. The global TB situation is further complicated by increasing patient numbers infected with Mycobacterium tuberculosis (M.tb.) strains resistant to either one or two of the first-line therapeutics, promoted by insufficient treatment length and/or drug levels due to adverse reactions and reduced patient compliance. An intriguing approach to improve anti-TB therapy relates to nanocarrier-based drug-delivery systems, which enhance local drug concentrations at infection sites without systemic toxicity. Recently developed anti-TB antibiotics, however, are lipophilic and difficult to transport in aqueous systems. Here, the very lipophilic TB-antibiotics bedaquiline (BDQ) and BTZ (1,3-benzothiazin-4-one 043) are prepared as high-dose, amorphous nanoparticles via a solvent-antisolvent technique. The nanoparticles exhibit mean diameters of 60 ± 13 nm (BDQ) and 62 ± 44 nm (BTZ) and have an extraordinarily high drug load with 69% BDQ and >99% BTZ of total nanoparticle mass plus a certain amount of surfactant (31% for BDQ, <1% for BTZ) to make the lipophilic drugs water-dispersible. Suspensions with high drug load (4.1 mg/mL BDQ, 4.2 mg/mL BTZ) are stable for several weeks. In vitro and in vivo studies employing M.tb.-infected macrophages and susceptible C3HeB/FeJ mice show promising activity, which outperforms conventional BDQ/BTZ solutions (in DMF or DMSO) with an up to 50% higher efficacy upon pulmonary delivery. In vitro, the BDQ/BTZ nanoparticles demonstrate their ability to cross the different biological barriers and to reach the site of the intracellular mycobacteria. In vivo, high amounts of the BDQ/BTZ nanoparticles are found in the lung and specifically inside granulomas, whereas only low BDQ/BTZ-nanoparticle levels are observed in spleen or liver. Thus, pulmonary delivered BDQ/BTZ nanoparticles are promising formulations to improve antituberculosis treatment.

Development of a Novel Lipid-Based Nanosystem Functionalized with WGA for Enhanced Intracellular Drug Delivery.

Despite a considerable number of new antibiotics under going clinical trials, treatment of intracellular pathogens still represents a major pharmaceutical challenge. The use of lipid nanocarriers provides several advantages such as protection from compound degradation, increased bioavailability, and controlled and targeted drug release. Wheat germ agglutinin (WGA) is known to have its receptors on the alveolar epithelium and increase phagocytosis. The present study aimed to produce nanostructured lipid carriers with novel glycosylated amphiphilic employed to attach WGA on the surface of the nanocarriers to improve intracellular drug delivery. High-pressure homogenization was employed to prepare the lipid nanocarriers. In vitro, high-content analysis and flow cytometry assay was employed to study the increased uptake by macrophages when the nanocarriers were grafted with WGA. A lipid nanocarrier with surface-functionalized WGA protein (~200 nm, PDI > 0.3) was successfully produced and characterized. The system was loaded with a lipophilic model compound (quercetin; QU), demonstrating the ability to encapsulate a high amount of compound and release it in a controlled manner. The nanocarrier surface functionalization with the WGA protein increased the phagocytosis by macrophages. The system proposed here has characteristics to be further explored to treat intracellular pathogens.

Probe ultrasonification of egg yolk plasma forms low-density lipoprotein nanoparticles that efficiently protect canine semen during cryofreezing.

Around the world, many couples have turned to in vitro fertilization as a viable solution to fertility issues. Low-density lipoprotein (LDL) is a protein best known for transporting fat molecules throughout the body, but it has also been shown to protect sperm cells during cryopreservation due to its micellar structure. In the present study, we aimed to evaluate different protocols for the preparation of nanoparticles from egg yolk plasma (EYP) containing LDL to improve the viability of cryopreserved canine semen. EYP was subjected to three distinct treatments: ultrasonification in an ultrasound bath at 40 kHz for 30 min (LDL-B); ultrasonification via an ultrasound probe at 50% amplitude for 30 min (LDL-P); and high-pressure homogenization at 10,000 PSI for six cycles (LDL-H). Sperm quality was assessed after thawing using computer-assisted sperm analysis and flow cytometry. The results revealed that compared to the EYP control, the LDL-P formulation presented significantly higher efficiency (p < 0.05) in maintaining total and progressive sperm motility, sperm membrane integrity and fluidity, and levels of intracellular reactive oxygen species. The LDL-P nanoparticles had an average size of approximately 250 nm, a PDI value of 0.3, and -1.15 mV of zeta potential, which are very important because it is an indicator of the stability of a colloidal dispersion. Therefore, we conclude that ultrasonication of EYP using a probe is an efficient method for the preparation of LDL nanoparticles that would enhance the cryoprotection of semen during freezing.

Development of Lipid Nanocarriers for Tuberculosis Treatment: Evaluation of Suitable Excipients and Nanocarriers.

BACKGROUND: Lipid nanocarriers have been widely tested as drug delivery systems to treat diseases due to their bioavailability, controlled release, and low toxicity. For the pulmonary route, the Food and Drug Administration favors the use of substances generally recognized as safe, as well as biodegradable and biocompatible to minimize the possibility of toxicity. Tuberculosis (TB) remains a public health threat worldwide, mainly due to the long treatment duration and adverse effects. Therefore, new drug delivery systems for treating TB are needed. OBJECTIVE: Physicochemical characterization of different lipid-based nanocarriers was used to optimize carrier properties. Optimized systems were incubated with Mycobacterium tuberculosis to assess whether lipid-based systems act as the energy source for the bacteria, which could be counterproductive to therapy. METHODS: Several excipients and surfactants were evaluated to prepare different types of nanocarriers using high-pressure homogenization. RESULTS: A mixture of trimyristin with castor oil was chosen as the lipid matrix after differential scanning calorimetry analysis. A mixture of egg lecithin and PEG-660 stearate was selected as an optimal surfactant system, as this mixture formed the most stable formulations. Three types of lipid nanocarriers, solid lipid nanoparticles, nanostructured lipid carriers (NLC), and nanoemulsions, were prepared, with the NLC systems showing the most suitable properties for further evaluation. It may provide the advantages of increasing the entrapment efficiency, drug release, and the ability to be lyophilized, producing powder for pulmonary administration as an alternative to entrap poor water-soluble molecules. CONCLUSION: Furthermore, the NLC system can be considered for use as a platform for the treatment of TB through the pulmonary route.

Different PEG-PLGA Matrices Influence In Vivo Optical/Photoacoustic Imaging Performance and Biodistribution of NIR-Emitting π-Conjugated Polymer Contrast Agents.

The π-conjugated polymer poly[2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b0]-dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)] (PCPDTBT) with deep-red/near-infrared (NIR) absorption and emission has been investigated as a contrast agent for in vivo optical and photoacoustic imaging. PCPDTBT is encapsulated within poly(ethylene glycol) methyl ether-block-poly(lactide-co-glycolide) (PEG2kDa -PLGA4kDa or PEG5kDa -PLGA55kDa ) micelles or enveloped by the phospholipid, 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000] (PEG2kDa -DPPE), to investigate the formulation effect on imaging performance, biodistribution, and biocompatibility. Nanoparticles that meet the quality requirements for parenteral administration are generated with similar physicochemical properties. Optical phantom imaging reveals that both PEG-PLGA systems exhibit a 30% higher signal-to-background ratio (SBR) than PEG2kDa -DPPE. This trend cannot be observed in a murine HeLa xenograft model following intravenous administration since dramatic differences in biodistribution are observed. PEG2kDa -PLGA4kDa systems accumulate more rapidly in the liver compared to other formulations and PEG2kDa -DPPE demonstrates a higher tumor localization. Protein content in the "hard" corona differs between formulations (PEG2kDa -DPPE < PEG2kDa -PLGA4kDa < PEG5kDa -PLGA55kDa ), although this observation alone does not explain biodistribution patterns. PEG2kDa -PLGA4kDa systems show the highest photoacoustic amplitude in a phantom, but also a lower signal in the tumor due to differences in biodistribution. This study demonstrates that formulations for conjugated polymer contrast agents can have significant impact on both imaging performance and biodistribution.

Anti-inflammatory and Antioxidant Effects of the Microalga Pediastrum boryanum in Carrageenan-Induced Rat Paw Edema

Abstract The potential use of microalgae in health has been the aim of different studies in the last years. This study investigated anti-inflammatory and antioxidant properties of three different extracts of green microalga Pediastrum boryanum in an acute inflammation model in rats. Rats were treated intraperitoneally with lyophilized biomass, the phenolic compounds and the extracellular extracts of P. boryanum before the induction of paw edema by the intraplantar injection of carrageenan. The edema and the levels of interleukin-1β and tumor necrosis factor-α were determined in the hind paw. Oxidative stress markers were analyzed in the liver and hepatic toxicity and genetic damage was evaluated in the blood. The results demonstrated that the three extracts of P. boryanum exhibited pronounced anti-oedematous property and decreased the levels of cytokines. The best results were provided by the phenolic compounds extract, that contains gallic, chlorogenic, protocathecuic and vanillic acid. A reduction in lipid peroxidation was observed after the treatment with lyophilized biomass and the extracellular extract improved the total antioxidant capacity of the liver. Moreover, no DNA damage and hepatic toxicity were observed after administration of P. boryanum extracts. In conclusion, these results suggest that P. boryanum can be an important source of anti-inflammatory compounds.

Tuberculosis Treatment Facilitated by Lipid Nanocarriers: Can Inhalation Improve the Regimen?

Tuberculosis (TB) remains a major global health problem. Conventional treatments fail either because of poor patient compliance with the drug regimen or due to the emergence of multidrug-resistant TB. Thus, not only has the discovery of new compounds and new therapeutic strategies been the focus of many types of research but also new routes of administration. Pulmonary drug delivery possesses many advantages, including the noninvasive route of administration, low metabolic activity, and control environment for systemic absorption, and avoids first-pass metabolism. The use of lipid nanocarriers provides several advantages such as protection of the compound's degradation, increased bioavailability, and controlled drug release. In this study, we review some points related to how the use of lipid nanocarriers can improve TB treatment with inhaled nanomedicines. This review also discusses the current approaches and formulations developed to achieve optimal pulmonary drug delivery systems with nanocarriers targeting alveolar macrophages.

Alternative Pharmaceutical Formulation for Oral Administration of Rifampicin.

Tuberculosis (TB) is considered an emergency global public health, mainly due to the TB-HIV co-infection, bacillus dormancy stage, and emergence of resistant strains. In addition, the therapeutic toxicity and its pharmacokinetic interactions with other drugs may influence treatment non-compliance, low serum concentration of drugs, and, consequently, treatment failure. Strategies using nanotechnology represent a new tool for the therapy, since they are effective delivery systems due to the possibility of solubilization of hydrophobic compounds, enable the production of formulations for oral use, and, in addition, increase bioavailability of drugs. This study aimed to develop a nanoemulsion (NE) containing rifampicin (RIF-NE) and evaluate its in vitro antimycobacterial activity using Resazurin Microtiter Assay against three Mycobacterium tuberculosis strains: two susceptible and a multidrug-resistant. Using the hot solvent diffusion method associated with phase inversion technique was possible to develop a liquid formulation containing 500 µg/mL rifampicin (RIF), which is a hydrophobic compound, of average size 25 nm. The results showed that the minimum inhibitory concentration of the encapsulated RIF was equal to the free form of RIF, indicating that the process of production of NEs did not affect the activity of the compound. Thus, RIF-NE could be a promising alternative for oral administration of RIF, being considered a child-friendly pharmaceutical formulation. Its application could avoid the administration of unknown and/or non-ideal concentrations, being functional in the regimes of prevention and treatment of TB and, in addition, in the fight against drug resistance.

Development of Nasal Lipid Nanocarriers Containing Curcumin for Brain Targeting.

BACKGROUND: Curcumin (CUR) has properties that can be useful for the treatment of Alzheimer's disease. Such properties are the inhibition of amyloid-ß-protein (Aß) aggregation, Aß-induced inflammation, and activities of ß-secretase and acetylcholinesterase. However, previous studies have revealed that CUR exhibited low bioavailability and difficulties in reaching the brain. OBJECTIVE: To overcome such drawbacks, this study aims at developing nasal lipid nanocarriers loaded with CUR to effectively target the brain. METHODS: The lipid nanocarriers (NE) were prepared using the hot solvent diffusion associated with the phase inversion temperature methods. Physico-chemical and morphological characterizations and in vitro drug release of the nanocarriers were carried out. The CUR permeation/retention was analyzed in Franz-type diffusion cell using porcine nasal mucosa. Confocal laser scan and histopathological studies were also performed. RESULTS: The results showed that the NE sizes ranged between 18 nm and 44 nm with negative zeta potential. The CUR content ranged from 0.24 to 1.50 mg/mL with an encapsulation efficiency of 99%. The profiles of CUR release indicated a biphasic kinetics. CUR-NE permeation across the porcine nasal mucosa was higher when compared to free CUR. These results have also been validated through an analysis on a confocal microscopy. In addition, no toxicity on the nasal mucosa has been observed in a histopathological analysis. CONCLUSION: These results suggest that it is possible to develop NEs with a high content of CUR and small particle size. Such an encapsulation increases the potential of CUR permeation across the porcine nasal mucosa.

Lipid-based nanocarrier for quercetin delivery: system characterization and molecular interactions studies.

The flavonoid quercetin (QU) is a naturally occurring compound with several biological activities. However, the oral bioavailability of this compound is very low due to the high pre-systemic metabolism in the colon and liver and its low water solubility. In this context, the development of QU-loaded nanocarriers (NEs) is a promising approach to improve the drug oral bioavailability. This study investigates the variation of the concentration of 12-hydroxystearic acid-polyethylene glycol copolymer, lecithin and castor oil (CO) as to increase the amount of QU encapsulated while maintaining physicochemical characteristics described in previous studies. To better understand the ability to load and release the drug, we investigated the molecular interactions between QU and NE. Lipid-based NEs were prepared using CO as oily phase and PEG 660-stearate and lecithin as surfactants. Hot solvent diffusion and phase inversion temperature were methods employed to produce NEs. The QU-NEs were investigated for physicochemical characteristics and in vitro drug release. Molecular interactions between QU and the NEs were monitored through the complementary infrared (Fourier transform infrared) and NMR. The results revealed that it was possible to incorporate higher amounts of QU in a lipid-based NE with a reduced size (20 nm). The system developed allow a sustained release of QU probably due to the shell formed by the surfactants around the NE and the flavonoid ordering effect in the emulsion hydrophobic regions, which may reduce the system permeability.

Anti-inflammatory Effect and Toxicology Analysis of Oral Delivery Quercetin Nanosized Emulsion in Rats.

PURPOSE: This study evaluates the advantage of the quercetin encapsulation in nanosized emulsion (QU-NE) administered orally in rats in order to demonstrate its anti-oedematous and antioxidant effects as well as its toxicity. METHODS: The nanocarriers were prepared using the hot solvent diffusion with the phase inversion temperature methods. The nanocarriers physicochemical properties were then investigated. The anti-edematous activity was tested using paw edema in rats. In addition, NF-kB expression in subcutaneous tissue of the paws was accessed by immunohistochemistry while the lipid peroxidation was analyzed in the liver by malondialdehyde reaction with thiobarbituric acid. Hematological, renal and hepatic toxicity as well as the genetic damage were also evaluated. RESULTS: The results demonstrated that QU-NE exhibited pronounced anti-oedematous property comparable to drug diclofenac. This effect was associated with NF-κB pathway inhibition. The lipid peroxidation was also only reduced in rats treated with QU-NE. Besides this, no genetic damage, hematological, renal or hepatic toxicities were observed after administration of QU-NE. CONCLUSIONS: These results suggest that quercetin nanosized emulsion exhibits anti-oedematous and antioxidant properties and does not demonstrate toxic effects. This indicates that it has a potential application in the treatment of inflammatory diseases.

Effects of the compounds resveratrol, rutin, quercetin, and quercetin nanoemulsion on oxaliplatin-induced hepatotoxicity and neurotoxicity in mice.

Oxaliplatin (OXA) is a platinum compound widely used in the treatment of some solid tumors, especially colorectal cancer. Despite its usefulness, oxaliplatin-associated neurotoxicity represents the main dose-limiting factor of this drug, and until now, there is no suitable treatment. Chemotherapy with oxaliplatin also increases the rate of developing hepatic damages with inflammatory activity, termed chemotherapy-associated steatohepatitis (CASH). In the present study, we aimed to compare the effects of a series of antioxidant compounds on simultaneous development of oxaliplatin-induced hepato- and neurotoxicity in mice. Mice BALB/c were treated with oxaliplatin for 6 weeks, 10 mg/kg, intraperitoneally, resulting in mechanical allodynia and hepatic steatosis. We administered the following antioxidant compounds--rutin (RT) (20 mg/kg), resveratrol (RVS) (100 mg/kg), quercetin (QT) (20 mg/kg), and quercetin nanoemulsion (NQT) (20 mg/kg)--daily by gavage to BALB/c, and N-acetylcysteine (NAC) was used as positive control. Treatments with RSV, RUT, or NQT were able to prevent mechanical allodynia when compared to the OXA group, and this effect was associated with decreased c-Fos immunopositivity in the lumbar spinal cord. Regarding the effects on steatohepatitis, RVS, QT, and NQT almost completely reversed the mean liver weight increase induced by OXA. In accordance with these previous data, histological evaluation indicated attenuation of all features of hepatic steatosis evaluated in RSV, RUT, QT, and NQT groups. These compounds were able to reduce the immunopositivity for the apoptosis marker caspase-3. On the other hand, only QT and NQT treatments were able to reduce neutrophil migration measured by myeloperoxidase (MPO) activity. These results suggest that the compounds tested, RSV, RUT, QT, and NQT, would be useful for the clinical treatment of neuro- and hepatoxicity induced by oxaliplatin.