Uptake of Eudragit Retard L (Eudragit® RL) Nanoparticles by Human THP-1 Cell Line and Its Effects on Hematology and Erythrocyte Damage in Rats

Biocompatibility of nano/micro-sized pyrophyllite particles by pulmo, liver, kidney and gastric mucosis cells

Pyrophyllite is the least studied natural clay in terms of its potential in biomedical applications, although there are many deposits of this aluminosilicate around the world. Genotoxicity study was performed in vitro for this mineral. Subsequently, Wister rats were exposed to the pyrophyllite micronized to below 100 µm. After the exposure period, histology of the lung, liver, kidney and gastric tissues were performed, followed by the stereological and hematological analysis. The physicochemical analyses revealed typical XRD characteristics of pyrophyllite clay with particle-size distribution ranging 50 nm-100 μm with stable mineral composition and unique buffering property to pH around 8. The results showed that there were no cytotoxic effects on to THP-1 cells, or genotoxicity of pyrophyllite measured by the Comet assay. In vivo studies are accompanied by the thorough physicochemical characterization of the micronized pyrophyllite. Histology of the lung tissue proved presence of an inflammatory reaction. On the other hand, gastric tissue has shown the selective accumulation of nanoparticles in enterocytes of the stomach only, as supported by ultrastructural analysis. Liver and kidney tissues have shown tolerability for pyrophyllite particles. The results give directions for further comprehensive studies of potential biomedical applications of the pyrophyllite.

Tamoxifen-Loaded Eudragit Nanoparticles: Quality by Design Approach for Optimization of Nanoparticles as Delivery System

Nanoparticles have numerous applications as drug carriers in drug delivery. The aim of the study was to produce tamoxifen nanoparticles with a defined size and higher encapsulation for efficient tissue uptake with controlled drug release. The quality by design approach was utilized to produce tamoxifen-loaded Eudragit nanoparticles by identifying the significant process variables using the nanoprecipitation method. The process variables (amount of drug, polymer, and surfactant) were altered to analyze the influence on particle size (PS), % encapsulation efficiency (EE). The results showed that the drug and polymer individually as well as collectively have an impact on PS, while the surfactant has no impact on the PS. The %EE was influenced by the surfactant individually and in interaction with the drug. The linear regression model was endorsed to fit the data showing high R2 values (PS, 0.9146, %EE, 0.9070) and low p values (PS, 0.0004, EE, 0.0005). The PS and EE were confirmed to be 178 nm and 90%, respectively. The nanoparticles were of spherical shape, as confirmed by SEM and TEM. The FTIR confirmed the absence of any incompatibility among the ingredients. The TGA confirmed that the NPs were thermally stable. The in vitro release predicted that the drug release followed Higuchi model.

Colon Targeted Eudragit Coated Beads Loaded with Optimized Fluvastatin-Scorpion Venom Conjugate as a Potential Approach for Colon Cancer Therapy: In Vitro Anticancer Activity and In Vivo Colon Imaging

Preclinical studies suggest that most of statins or 3‑hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors possess pleiotropic anticancer activity. The aim of the present work was to investigate the conjugation of the statin fluvastatin (FLV) with scorpion venom (SV), a natural peptide with proven anticancer properties, to enhance FLV cytotoxic activity and prepare colon targeted FLV-SV nanoconjugate beads for management of colon cancer. Response surface design was applied for the optimization of FLV-SV nanoconjugates. FLV-SV particle size and zeta potential were selected as responses. Cytotoxicity of optimized FLV-SV nanoconjugates was carried out on Caco2 cell line. Colon targeted alginate coated Eudragit S100 (ES100) beads for the optimized formula were prepared with the utilization of barium sulfate (BaSO4) as radiopaque contrast substance. Results revealed that optimized FLV-SV nanoconjugates showed a size of 71.21 nm, while the zeta potential was equal to 29.13 mV. Caco2 cells were considerably more sensitive to the FLV-SV formula (half-maximal inhibitory concentration (IC50) = 11.91 µg/mL) compared to SV and FLV used individually, as shown by values of IC50 equal to 30.23 µg/mL and 47.68 µg/mL, respectively. In vivo imaging of colon targeted beads, carried out by employing real-time X-ray radiography, confirmed the efficiency of colon targeted beads. Overall our results indicate that the optimized FLV-SV nanoconjugate loaded alginate coated ES100 beads could represent a promising approach for colon cancer with efficient colon targeting ability.

Alpha-mangostin and resveratrol, dual-drugs-loaded mucoadhesive thiolated chitosan-based nanoparticles for synergistic activity against colon cancer cells

Alpha-mangostin (M) and resveratrol (R), dual-drugs-loaded mucoadhesive thiolated chitosan-based nanoparticles (NPs) coated by Eudragit® S100 (S) were developed for colon-specific delivery and synergistic activity against colon cancer cells. The NPs were prepared by the ionotropic gelation method and coated with S. The particle size and zeta potential of NPs before and after the coating process were observed. The M and R loading efficiency, mucoadhesive properties, as well as release patterns were examined. Moreover, the activity against colon cancer cells of M, R, and NPs were studied for their synergistic activity. M and R-loaded NPs (MR-TNPs) were spherical in shape with sizes of around 540 nm and zeta potential of +39 mV. The S coating of MR-TNPs provided larger particle sizes which offered lower zeta potential. However, it created an increase in M and R loading, prevented M and R release at the upper gastrointestinal tract, and enhanced M and R reaching the colon. S dissolved at pH > 7.0 while thiolated chitosan formed the mucoadhesion, resulting in M and R remaining in the colon and allowing them to enter the colon cancer cells. The half-maximal inhibitory concentration values of NPs was dramatically decreased when M and R were dually loaded into the NPs, which indicated significantly higher activity against colon cancer cells. Moreover, M and R loading at this ratio applied synergistic efficiency. The results illustrated that NPs successfully loaded drugs and achieved synergistic efficiency. This system could be promising in facilitating targeted nanomedicines for the treatment of colon cancer.

Development and optimization of paclitaxel loaded Eudragit/PLGA nanoparticles by simplex lattice mixture design: Exploration of improved hemocompatibility and in vivo kinetics

Anemia is the most common hematological abnormality of chemotherapy, which is responsible for poor clinical outcomes. To overcome this complication, the present study was aimed for developing a Eudragit/polylactic-co-glycolic acid (PLGA) based nanoparticulate system for a model drug paclitaxel (PTX). The study was planned using a simplex lattice mixture design. PTX nanoparticles (PTXNp) were evaluated in vitro for physicochemical properties, hemolytic effects and cytotoxic effects. Further, the nanoparticles were subjected to in vivo screening using rats for hemocompatibility, pharmacokinetic profile, and biodistribution to the vital organs. The PTXNps were 65.77-214.73 nm in size, showed more than 60% sustained drug release in 360 h and caused less than 8% hemolysis. The parameters like red blood cell count, activated partial thromboplastin time (aPTT), prothrombin time (PT) and C3 complement were similar to the negative control. Cytotoxicity results suggested that all the PTXNp demonstrated drug concentration-dependent cytotoxicity. The in vivo pharmacokinetic study concluded that PTXNp formulations had significantly higher blood AUC (93.194.55-163,071.15 h*ng/mL), longer half-lives (5.80-6.35 h) and extended mean residence times (6.05-8.54 h) in comparison to PTX solution (p < 0.05). Overall, the study provides a nanoparticulate drug delivery system to deliver PTX safely and effectively along with reducing the associated hematological adverse effects.

A second-generation micro/nano capsules of an endogenous primary un-metabolised bile acid, stabilized by Eudragit-alginate complex with antioxidant compounds

Bile acids (BAs) are amphiphilic compounds and of recently have demonstrated wide range of formulation stabilizing effects. A recent study showed that primary un-metabolised bile acids (PUBAs) have β-cell protective effects, and synergistic antidiabetic effects when combined with antioxidant and anti-inflammatory drugs, such as probucol (PB). Thus, this study aimed to design and test microcapsules containing a PUBA incorporated with PB and an alginate-Eudragit matrix.

Six types of microcapsules were developed without (control) or with (test) PUBA, and tested for internal and external features and β-cell protective effects.

The incorporation of PB-alginate-Eudragit with PUBA produced stable microcapsules but did not exert consistent positive effects on cell viability in the hyperglycaemic state, which suggests that PUBA in alginate-Eudragit matrices did not exhibit synergistic effects with PB nor exerted antidiabetic effects.

Low Molecular Weight Chitosan-Coated PLGA Nanoparticles for Pulmonary Delivery of Tobramycin for Cystic Fibrosis

(1) Background: Poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) loaded with Tobramycin were prepared using a solvent-evaporation method. (2) Methods: The NPs were coated with low molecular weight chitosan (LMWC) to enhance the mucoadhesiveness of PLGA-NPs. The following w/w ratios of tobramycin to LMWC were prepared: control (0:0.50), F₀ (1:0.25), F₀.₅ (1:0.5), and F₁ (1:1). (3) Results: The results showed that the size of the particles increased from 220.7 nm to 575.77 nm as the concentration of LMWC used in the formulation increased. The surface charge was also affected by the amount of LMWC, where uncoated-PLGA nanoparticles had negative charges (−2.8 mV), while coated-PLGA NPs had positive charges (+33.47 to +50.13 mV). SEM confirmed the size and the spherical homogeneous morphology of the NPs. Coating the NPs with LMWC enhanced the mucoadhesive properties of the NPs and sustained the tobramycin release over two days. Finally, all NPs had antimicrobial activity that increased as the amount of LMWC increased. (4) Conclusion: In conclusion, the formulation of mucoadhesive, controlled-release, tobramycin-LMWC-PLGA nanoparticles for the treatment of P. aeruginosa in cystic fibrosis patients is possible, and their properties could be controlled by controlling the concentration of LMWC.

Uptake and Intracellular Fate of Engineered Nanoparticles in Mammalian Cells: Capabilities and Limitations of Transmission Electron Microscopy-Polymer-Based Nanoparticles

In order to elucidate mechanisms of nanoparticle (NP)-cell interactions, a detailed knowledge about membrane-particle interactions, intracellular distributions, and nucleus penetration capabilities, etc. becomes indispensable. The utilization of NPs as additives in many consumer products, as well as the increasing interest of tailor-made nanoobjects as novel therapeutic and diagnostic platforms, makes it essential to gain deeper insights about their biological effects. Transmission electron microscopy (TEM) represents an outstanding method to study the uptake and intracellular fate of NPs, since this technique provides a resolution far better than the particle size. Additionally, its capability to highlight ultrastructural details of the cellular interior as well as membrane features is unmatched by other approaches. Here, a summary is provided on studies utilizing TEM to investigate the uptake and mode-of-action of tailor-made polymer nanoparticles in mammalian cells. For this purpose, the capabilities as well as limitations of TEM investigations are discussed to provide a detailed overview on uptake studies of common nanoparticle systems supported by TEM investigations. Furthermore, methodologies that can, in particular, address low-contrast materials in electron microscopy, i.e., polymeric and polymer-modified nanoparticles, are highlighted.

Development, characterization, and in vivo assessment of mucoadhesive nanoparticles containing fluconazole for the local treatment of oral candidiasis

This study aimed to develop a suitable buccal mucoadhesive nanoparticle (NP) formulation containing fluconazole for the local treatment of oral candidiasis. The suitability of the prepared formulations was assessed by means of particle size (PS), polydispersity index, and zeta potential measurements, morphology analysis, mucoadhesion studies, drug entrapment efficiency (EE), in vitro drug release, and stability studies. Based on the optimum NP formulation, ex vivo drug diffusion and in vitro cytotoxicity studies were performed. Besides, evaluation of the antifungal effect of the optimum formulation was evaluated using agar diffusion method, fungicidal activity-related in vitro release study, and time-dependent fungicidal activity. The effect of the optimum NP formulation on the healing of oral candidiasis was investigated in an animal model, which was employed for the first time in this study. The zeta potential, mucoadhesion, and in vitro drug release studies of various NP formulations revealed that chitosan-coated NP formulation containing EUDRAGIT(®) RS 2.5% had superior properties than other formulations. Concerning the stability study of the selected formulation, the formulation was found to be stable for 6 months. During the ex vivo drug diffusion study, no drug was found in receptor phase, and this is an indication of local effect. The in vitro antifungal activity studies showed the in vitro efficacy of the NP against Candida albicans for an extended period. Also, the formulation had no cytotoxic effect at the tested concentration. For the in vivo experiments, infected rabbits were successfully treated with local administration of the optimum NP formulation once a day. This study has shown that the mucoadhesive NP formulation containing fluconazole is a promising candidate with once-a-day application for the local treatment of oral candidiasis.