Correction: Eid et al. Interference with TGFß1-Mediated Inflammation and Fibrosis Underlies Reno-Protective Effects of the CB1 Receptor Neutral Antagonists AM6545 and AM4113 in a Rat Model of Metabolic Syndrome. Molecules 2021, 26, 866.

The authors wish to make the following changes to the paper [...].

Optimized Apamin-Mediated Nano-Lipidic Carrier Potentially Enhances the Cytotoxicity of Ellagic Acid against Human Breast Cancer Cells.

Ellagic acid has recently attracted increasing attention regarding its role in the prevention and treatment of cancer. Surface functionalized nanocarriers have been recently studied for enhancing cancer cells' penetration and achieving better tumor-targeted delivery of active ingredients. Therefore, the present work aimed at investigating the potential of APA-functionalized emulsomes (EGA-EML-APA) for enhancing cytototoxic activity of EGA against human breast cancer cells. Phospholipon® 90 G: cholesterol molar ratio (PC: CH; X1, mole/mole), Phospholipon® 90 G: Tristearin weight ratio (PC: TS; X2, w/w) and apamin molar concentration (APA conc.; X3, mM) were considered as independent variables, while vesicle size (VS, Y1, nm) and zeta potential (ZP, Y2, mV) were studied as responses. The optimized formulation with minimized vs. and maximized absolute ZP was predicted successfully utilizing a numerical technique. EGA-EML-APA exhibited a significant cytotoxic effect with an IC50 value of 5.472 ± 0.21 µg/mL compared to the obtained value from the free drug 9.09 ± 0.34 µg/mL. Cell cycle profile showed that the optimized formulation arrested MCF-7 cells at G2/M and S phases. In addition, it showed a significant apoptotic activity against MCF-7 cells by upregulating the expression of p53, bax and casp3 and downregulating bcl2. Furthermore, NF-κB activity was abolished while the expression of TNfα was increased confirming the significant apoptotic effect of EGA-EML-APA. In conclusion, apamin-functionalized emulsomes have been successfully proposed as a potential anti-breast cancer formulation.

Interference with TGFß1-Mediated Inflammation and Fibrosis Underlies Reno-Protective Effects of the CB1 Receptor Neutral Antagonists AM6545 and AM4113 in a Rat Model of Metabolic Syndrome.

The role of cannabinoid receptors in nephropathy is gaining much attention. This study investigated the effects of two neutral CB1 receptor antagonists, AM6545 and AM4113, on nephropathy associated with metabolic syndrome (MetS). MetS was induced in rats by high-fructose high-salt feeding for 12 weeks. AM6545, the peripheral silent antagonist and AM4113, the central neutral antagonist were administered in the last 4 weeks. At the end of study, blood and urine samples were collected for biochemical analyses while the kidneys were excised for histopathological investigation and transforming growth factor beta 1 (TGFß1) measurement. MetS was associated with deteriorated kidney function as indicated by the elevated proteinuria and albumin excretion rate. Both compounds equally inhibited the elevated proteinuria and albumin excretion rate while having no effect on creatinine clearance and blood pressure. In addition, AM6545 and AM4113 alleviated the observed swelling and inflammatory cells infiltration in different kidney structures. Moreover, AM6545 and AM4113 alleviated the observed histopathological alterations in kidney structure of MetS rats. MetS was associated with a ten-fold increase in urine uric acid while both compounds blocked this increase. Furthermore, AM6545 and AM4113 completely prevented the collagen deposition and the elevated expression of the TGFß1 seen in MetS animals. In conclusion, AM6545 and AM4113, possess reno-protective effects by interfering with TGFß1-mediated renal inflammation and fibrosis, via peripheral action.

Fluvastatin-Loaded Emulsomes Exhibit Improved Cytotoxic and Apoptosis in Prostate Cancer Cells.

Fluvastatin (FLV) is known to inhibit the 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA), which is over-expressed in various cancers. FLV has been reported to decrease cancer development and metastasis. However, because of low bioavailability, extensive first-pass metabolism and short half-life of FLV (1.2 h), it is not appropriate for clinical application. Therefore, FLV-loaded emulsomes were formulated and optimized using Box-Behnken experimental design to achieve higher efficiency of formulation. Antitumor activity of optimized FLV-loaded emulsomes was evaluated in prostate cancer cells using cell cytotoxicity, apoptotic activity, cell cycle analysis, and enzyme-linked immunosorbent assay. The FLV-loaded emulsomes exhibited a monodispersed size distribution with a mean particle size less than 100 nm as measured by zetasizer. The entrapment efficiency was found to be 93.74% with controlled drug release profile. FLV-EMLs showed a significant inhibitory effect on the viability of PC3 cells when compared to the free FLV (P < 0.0025). Furthermore, FLV-EMLs showed significant arrest in G2/M and increase in percentage of apoptotic cells as compared to free FLV. FLV-EMLs were more effective than free FLV in reducing mitochondrial membrane potential and increase in caspase-3 activity. These results suggesting that FLV-EMLs caused cell cycle arrest which clarifies its significant antiproliferative effect compared to the free drug. Therefore, optimized FLV-EMLs may be an effective carrier for FLV in prostate cancer treatment.

Chitosan Coated Microparticles Enhance Simvastatin Colon Targeting and Pro-Apoptotic Activity.

This work aimed at improving the targeting and cytotoxicity of simvastatin (SMV) against colon cancer cells. SMV was encapsulated in chitosan polymers, followed by eudragit S100 microparticles. The release of SMV double coated microparticles was dependent on time and pH. At pH 7.4 maximum release was observed for 6 h. The efficiency of the double coat to target colonic tissues was confirmed using real-time X-ray radiography of iohexol dye. Entrapment efficiency and particle size were used in the characterization of the formula. Cytotoxicity of SMV microparticles against HCT-116 colon cancer cells was significantly improved as compared to raw SMV. Cell cycle analysis by flow cytomeric technique indicated enhanced accumulation of colon cancer cells in the G2/M phase. Additionally, a significantly higher cell fraction was observed in the pre-G phase, which highlighted enhancement of the proapoptotic activity of SMV prepared in the double coat formula. Assessment of annexin V staining was used for confirmation. Cell fraction in early, late and total cell death were significantly elevated. This was accompanied by a significant elevation of cellular caspase 3 activity. In conclusion, SMV-loaded chitosan coated with eudragit S100 formula exhibited improved colon targeting and enhanced cytotoxicity and proapoptotic activity against HCT-116 colon cancer cells.

Effects of the CB1 Receptor Antagonists AM6545 and AM4113 on Insulin Resistance in a High-Fructose High-Salt Rat Model of Metabolic Syndrome.

Background and Objectives: Insulin resistance (IR) is a serious condition leading to development of diabetes and cardiovascular complications. Hyper-activation of cannabinoid receptors-1 (CB1) has been linked to the development of metabolic disorders such as IR. Therefore, the effect of blocking CB1 on the development of IR was investigated in the present study. Materials and Methods: A 12-week high-fructose/high-salt feeding model of metabolic syndrome was used to induce IR in male Wistar rats. For this purpose, two different CB1-antagonists were synthesized and administered to the rats during the final four weeks of the study, AM6545, the peripheral neutral antagonist and AM4113, the central neutral antagonist. Results: High-fructose/salt feeding for 12 weeks led to development of IR while both AM6545 and AM4113, administered in the last 4 weeks, significantly inhibited IR. This was correlated with increased animal body weight wherein both AM6545 and AM4113 decreased body weight in IR animals but with loss of IR/body weight correlation. While IR animals showed significant elevations in serum cholesterol and triglycerides with no direct correlation with IR, both AM6545 and AM4113 inhibited these elevations, with direct IR/cholesterol correlation in case of AM6545. IR animals had elevated serum uric acid, which was reduced by both AM6545 and AM4113. In addition, IR animals had decreased adiponectin levels and elevated liver TNFα content with strong IR/adiponectin and IR/TNFα correlations. AM6545 inhibited the decreased adiponectin and the increased TNFα levels and retained the strong IR/adiponectin correlation. However, AM4113 inhibited the decreased adiponectin and the increased TNFα levels, but with loss of IR/adiponectin and IR/TNFα correlations. Conclusions: Both CB1 neutral antagonists alleviated IR peripherally, and exerted similar effects on rats with metabolic syndrome. They also displayed anti-dyslipidemic, anti-hyperurecemic and anti-inflammatory effects. Overall, these results should assist in the development of CB1 neutral antagonists with improved safety profiles for managing metabolic disorders.

Optimization of the Conditions for Plasmid DNA Delivery and Transfection with Self-Assembled Hyaluronic Acid-Based Nanoparticles.

Polymeric systems have been extensively studied as polyelectrolyte complexes to enhance the cellular delivery and transfection efficiency of genetic materials, such as plasmid DNA (pDNA). Here, self-assembled nanoparticles were formulated by complexation of hyaluronic acid (HA)-conjugated poly(ethylene glycol) (HA-PEG) and poly(ethylenimine) (HA-PEI), respectively, with pDNA creating relatively small, stable, and multifunctional nanoparticle complex formulations with high transfection efficiency. This formulation strategy offers high gene expression efficiency and negligible cytotoxicity in HeLa and A549 human lung cancer cell lines. To develop the ideal formulation, in vitro transfection efficiency was studied for three different nanoparticle formulations (HA-PEI/HA-PEG, HA-PEI, and HA-PEG) with different concentrations. The combination of the three polymers (HA, PEG, and PEI) was significant for the formulation to achieve the maximum gene expression results. The nanoparticles were found to be stable for up to a week at 4 °C conditions. Overall, these HA-based nanoparticles showed promising aspects that can be utilized in the designing of gene delivery vectors for cancer therapy.

Encapsulation of Lovastatin in Zein Nanoparticles Exhibits Enhanced Apoptotic Activity in HepG2 Cells.

Research on statins highlights their potent cytotoxicity against cancer cells and their potential for cancer prevention. The aim of the current study was to examine whether loading lovastatin (LVS) in zein (ZN) nanoparticles (NPs) would potentiate the anti-proliferative effects of LVS and enhance its proliferation-inhibiting activity in HepG2 cells. LVS-ZN NPs were prepared and showed excellent characteristics, with respect to their particle size, zeta potential, diffusion, and entrapment efficiency. In addition, they showed the most potent anti-proliferative activity against HepG2 cells. ZN alone showed an observable anti-proliferative that was significantly higher than that of raw LVS. Furthermore, LVS uptake by HepG2 cells was greatly enhanced by the formulation in ZN. A cell cycle analysis indicated that LVS induced a significant cell accumulation in the G2/M and pre-G phases. In this regard, the LVS-ZN NPs exhibited the highest potency. The accumulation in the pre-G phase indicated an enhanced pro-apoptotic activity of the prepared formula. The cells incubated with the LVS-ZN NPs showed the highest percentage of cells with annexin-V positive staining. In addition, the same incubations showed the highest content of caspase-3 enzyme in comparison to raw LVS or ZN. Thus, the loading of LVS in ZN nanoparticles enhances its anti-proliferative activity against HepG2 cells, which is attributed, at least partly, to the enhanced cellular uptake and the induction of apoptosis.

Preparation, Optimization, and Evaluation of Hyaluronic Acid-Based Hydrogel Loaded with Miconazole Self-Nanoemulsion for the Treatment of Oral Thrush.

Miconazole nitrate (MZ) is a BCS class II antifungal poorly water-soluble drug with limited dissolution properties and gastrointestinal side effects. Self-nanoemulsifying delivery system-based gel of MZ can improve both solubility and oral mucosal absorption with enhanced antifungal activity. The study aims to formulate MZ self-nanoemulsion (MZ-NE) and combine it within hyaluronic acid-based gel. MZ solubility in various oils, surfactants, and cosurfactant used in NE formulations were evaluated. Mixture design was implemented to optimize the levels of NE components as a formulation variable to study their effects on the mean globule size and antifungal inhibition zones. Further, the optimized MZ-NE was loaded into a hyaluronic acid gel base. Rheological behavior of the prepared gel was assessed. Ex vivo permeability of optimized formulation across buccal mucous of sheep and inhibition against Candida albicans were examined. Mixture design was used to optimize the composition of MZ-NE formulation as 22, 67, and 10% for clove oil, Labrasol, and propylene glycol, respectively. The optimized formulation indicated globule size of 113 nm with 29 mm inhibition zone. Pseudoplastic flow with thixotropic behavior was observed, which is desirable for oral gels. The optimized formulation exhibited higher ex vivo skin permeability and enhanced antifungal activity by 1.85 and 2.179, respectively, compared to MZ-SNEDDS, and by 1.52 and 1.72 folds, respectively, compared to marketed gel. Optimized MZ-NE hyaluronic acid-based oral gel demonstrated better antifungal activity, indicating its potential in oral thrush pharmacotherapy.

Antihyperglycemic activities of extracts of the mistletoes Plicosepalus acaciae and P. curviflorus in comparison to their solid lipid nanoparticle suspension formulations.

The antihyperglycemic activity of the extracts and preparations of solid lipid nanoparticle suspensions of two mistletoes growing in Saudi Arabia, Plicosepalus acaciae and P. curviflorus, as well as their possible antioxidant effect were investigated in a type 2 diabetic animal model. Type 2 diabetes was induced in adult male Wistar rats by a high-fat diet followed by injection of streptozotocin (STZ). The diabetic rats were treated in parallel with pioglitazone hydrochloride (PIO), non-toxic extracts of P. acaciae and P. curviflorus, as well as three different solid lipid nanoparticle (SLN) suspension formulations prepared from each of the two extracts. Blood glucose level, insulin resistance, oxidative stress parameters, and antioxidant markers were determined. The total extracts of P. acaciae and P. curviflorus as well as the SLN formulations exhibited a significant blood glucose-lowering effect associated with antioxidant effects in the diabetic rats. The SLN preparation with the highest lipid content gave the best result. Reduction of hyperglycemia and insulin resistance in the diabetic rats was, at least partly, due to the antioxidant activities of the extracts and their SLN formulations.

RETRACTED: Tzeyung et al. Fabrication, Optimization, and Evaluation of Rotigotine-Loaded Chitosan Nanoparticles for Nose-To-Brain Delivery. Pharmaceutics 2019, 11, 26.

The journal retracts the article, "Fabrication, Optimization, and Evaluation of Rotigotine-Loaded Chitosan Nanoparticles for Nose-To-Brain Delivery" [...].

RETRACTED: Aldawsari et al. Gum Acacia Functionalized Colloidal Gold Nanoparticles of Letrozole as Biocompatible Drug Delivery Carrier for Treatment of Breast Cancer. Pharmaceutics 2021, 13, 1554.

The Pharmaceutics Editorial Office retracts the article, "Gum Acacia Functionalized Colloidal Gold Nanoparticles of Letrozole as Biocompatible Drug Delivery Carrier for Treatment of Breast Cancer" [...].

RETRACTED: Aldawsari et al. Lipidic Nano-Sized Emulsomes Potentiates the Cytotoxic and Apoptotic Effects of Raloxifene Hydrochloride in MCF-7 Human Breast Cancer Cells: Factorial Analysis and In Vitro Anti-Tumor Activity Assessment. Pharmaceutics 2021, 13, 783.

The journal retracts the article "Lipidic Nano-Sized Emulsomes Potentiates the Cytotoxic and Apoptotic Effects of Raloxifene Hydrochloride in MCF-7 Human Breast Cancer Cells: Factorial Analysis and In Vitro Anti-Tumor Activity Assessment" [...].

RETRACTED: Fahmy et al. Intranasal Niosomal In Situ Gel as a Promising Approach for Enhancing Flibanserin Bioavailability and Brain Delivery: In Vitro Optimization and Ex Vivo/In Vivo Evaluation. Pharmaceutics 2020, 12, 485.

This journal retracts the article "Intranasal Niosomal In Situ Gel as a Promising Approach for Enhancing Flibanserin Bioavailability and Brain Delivery: In Vitro Optimization and Ex Vivo/In Vivo Evaluation" [...].

RETRACTED: Alhakamy et al. Optimized Icariin Phytosomes Exhibit Enhanced Cytotoxicity and Apoptosis-Inducing Activities in Ovarian Cancer Cells. Pharmaceutics 2020, 12, 346.

The journal retracts the article, "Optimized Icariin Phytosomes Exhibit Enhanced Cytotoxicity and Apoptosis-Inducing Activities in Ovarian Cancer Cells" [...].

RETRACTED: Alhakamy et al. Development and Optimization of Luliconazole Spanlastics to Augment the Antifungal Activity against Candida albicans. Pharmaceutics 2021, 13, 977.

The journal retracts the article, "Development and Optimization of Luliconazole Spanlastics to Augment the Antifungal Activity against Candida albicans" [...].

RETRACTED: Ahmed et al. Application of Nanopharmaceutics for Flibanserin Brain Delivery Augmentation Via the Nasal Route. Nanomaterials 2020, 10, 1270.

The Journal retracts the article "Application of Nanopharmaceutics for Flibanserin Brain Delivery Augmentation Via the Nasal Route" [...].

RETRACTED: Alhakamy et al. Optimized Ellagic Acid-Ca Pectinate Floating Beads for Gastroprotection against Indomethacin-Induced Gastric Injury in Rats. Biomolecules 2020, 10, 1006.

The journal retracts the article, "Optimized Ellagic Acid-Ca Pectinate Floating Beads for Gastroprotection against Indomethacin-Induced Gastric Injury in Rats" [...].

Three-Dimensional In Vitro Cell Culture Models for Efficient Drug Discovery: Progress So Far and Future Prospects.

Despite tremendous advancements in technologies and resources, drug discovery still remains a tedious and expensive process. Though most cells are cultured using 2D monolayer cultures, due to lack of specificity, biochemical incompatibility, and cell-to-cell/matrix communications, they often lag behind in the race of modern drug discovery. There exists compelling evidence that 3D cell culture models are quite promising and advantageous in mimicking in vivo conditions. It is anticipated that these 3D cell culture methods will bridge the translation of data from 2D cell culture to animal models. Although 3D technologies have been adopted widely these days, they still have certain challenges associated with them, such as the maintenance of a micro-tissue environment similar to in vivo models and a lack of reproducibility. However, newer 3D cell culture models are able to bypass these issues to a maximum extent. This review summarizes the basic principles of 3D cell culture approaches and emphasizes different 3D techniques such as hydrogels, spheroids, microfluidic devices, organoids, and 3D bioprinting methods. Besides the progress made so far in 3D cell culture systems, the article emphasizes the various challenges associated with these models and their potential role in drug repositioning, including perspectives from the COVID-19 pandemic.