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

RETRACTED: Alhakamy et al. Chitosan-Based Microparticles Enhance Ellagic Acid's Colon Targeting and Proapoptotic Activity. Pharmaceutics 2020, 12, 652

The journal retracts the article "Chitosan-Based Microparticles Enhance Ellagic Acid's Colon Targeting and Proapoptotic Activity" [...].

Colon targeted releases and uptakes of paclitaxel loaded in modified porous starch

Hyaluronic acid can modify porous starch through cross-linking and hydrogen bonding, effectively achieving a paclitaxel entrapment efficiency of ∼92 % and drug loading of ∼23 %. In this study, the pores and intergranular gaps of porous starch were filled with paclitaxel under solvent volatilization, and the enrichment process and its characteristics were recorded using a microscope. The paclitaxel-loaded particles were coated with chitosan-phytic acid to target the colon. In vivo imaging in mice showed that the capsule released paclitaxel in the colon rather than in the upper digestive tract, and the paclitaxel distribution in the main organs at 24 h was significantly lower than that of raw paclitaxel. Hyaluronic acid-modified porous starch can target cancer cells. Cell internalization of paclitaxel mediated by hyaluronic acid was approximately 1.97 times that of raw paclitaxel, higher than that of receptor-shielded cells and cells incubated with unmodified carriers, as evidenced by the accumulation of fluorescent paclitaxel in the nucleus and marked cell apoptosis. The hyaluronic acid-modified porous starch system is an effective method for the high-load and targeted release of hydrophobic anticancer drugs.

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.

Simvastatin Coadministration Modulates the Electrostatically Driven Incorporation of Doxorubicin into Model Lipid and Cell Membranes

Understanding the interactions between drugs and lipid membranes is a prerequisite for finding the optimal way to deliver drugs into cells. Coadministration of statins and anticancer agents has been reported to have a positive effect on anticancer therapy. In this study, we elucidate the mechanism by which simvastatin (SIM) improves the efficiency of biological membrane penetration by the chemotherapeutic agent doxorubicin (DOX) in neutral and slightly acidic solutions. The incorporation of DOX, SIM, or a combination of them (DOX:SIM) into selected single-component lipid membranes, zwitterionic unsaturated 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), neutral cholesterol, and negatively charged 1,2-dimyristoyl-sn-glycero-3-phospho-l-serine (DMPS) was assessed using the Langmuir method. The penetration of neutral lipid monolayers by the codelivery of SIM and DOX was clearly facilitated at pH 5.5, which resembles the pH conditions of the environment of cancer cells. This effect was ascribed to partial neutralization of the DOX positive charge as the result of intermolecular interactions between DOX and SIM. On the other hand, the penetration of the negatively charged DMPS monolayer was most efficient in the case of the positively charged DOX. The efficiency of the drug delivery to the cell membranes was evaluated under in vitro conditions using a panel of cancer-derived cell lines (A172, T98G, and HeLa). MTS and trypan blue exclusion assays were performed, followed by confocal microscopy and spheroid culture tests. Cells were exposed to either free drugs or drugs encapsulated in lipid carriers termed cubosomes. We demonstrated that the viability of cancer cells exposed to DOX was significantly impaired in the presence of SIM, and this phenomenon was greatly magnified when DOX and SIM were coencapsulated in cubosomes. Overall, our results confirmed the utility of the DOX:SIM combination delivery, which enhances the interactions between neutral components of cell membranes and positively charged chemotherapeutic agents.

Design and Development of Neomycin Sulfate Gel Loaded with Solid Lipid Nanoparticles for Buccal Mucosal Wound Healing

Drug administration to the wound site is a potential method for wound healing. The drug retention duration should be extended, and drug permeability through the buccal mucosal layer should be regulated. Oral wounds can be caused by inflammation, ulcers, trauma, or pathological lesions; if these wounds are not treated properly, they can lead to pain, infection, and subsequent undesirable scarring. This study aimed to develop Kolliphor-407 P-based gel containing neomycin sulfate (NES) loaded in solid lipid nanoparticles (SLNs) and enhance the antimicrobial activity. By considering lipid concentrations and achieving the lowest particle size (Y1) and maximum entrapment (EE-Y2) effectiveness, the formulation of NES-SLN was optimized using the Box–Behnken design. For the selected responses, 17 runs were formulated (as anticipated by the Design-Expert software) and evaluated accordingly. The optimized formulation could achieve a particle size of 196.25 and EE of 89.27% and was further utilized to prepare the gel formulation. The NES-SLN-G formula was discovered to have a smooth, homogeneous structure and good mechanical and rheological properties. After 24 h of treatment, NES-SLN-G showed a regulated in vitro drug release pattern, excellent ex vivo permeability, and increased in vitro antibacterial activity. These findings indicate the potential application of NES-SLN-loaded gels as a promising formulation for buccal mucosal wound healing.

Antitumor Effect of Simvastatin in Combination With DNA Methyltransferase Inhibitor on Gastric Cancer via GSDME-Mediated Pyroptosis

Gasdermin E (GSDME) is one of the executors of pyroptosis, a type of programmed lytic cell death, which can be triggered by caspase-3 activation upon stimulation. Silenced GSDME expression due to promoter hypermethylation is associated with gastric cancer (GC), which is confirmed in the present study by bioinformatics analysis and methylation-specific PCR (MSP) test of GC cell lines and clinical samples. GC cell lines and mouse xenograft models were used to investigate the pyroptosis-inducing effect of the common cholesterol-depleting, drug simvastatin (SIM), allied with upregulating GSDME expression by doxycycline (DOX)- inducible Tet-on system or DNA methyltransferase inhibitor 5-Aza-2′-deoxycytidine (5-Aza-CdR). Cell viability assessment and xenograft tumour growth demonstrated that the tumour inhibition effects of SIM can be enhanced by elevated GSDME expression. Morphological examinations and assays measuring lactate dehydrogenase (LDH) release and caspase-3/GSDME protein cleavage underlined the stimulation of pyroptosis as an important mechanism. Using short hairpin RNA (shRNA) knockdown of caspase-3 or GSDME, and caspase-3-specific inhibitors, we provided evidence of the requirement of caspase-3/GSDME in the pyroptosis process triggered by SIM. We conclude that reactivating GSDME expression and thereby inducing cancer cell-specific pyroptosis could be a potential therapeutic strategy against GC.

Assessment of Amentoflavone Loaded Sub-Micron Particle Preparation using Supercritical Antisolvent for its Antitumor Activity

Introduction:

The amentoflavone (AMF) loaded polymeric sub-micron particles were prepared using supercritical antisolvent (SAS) technology with the aim of improving the anticancer activity of AMF.

Materials and Methods:

Zein and phospholipid mixtures composed of Hydrogenated Phosphatidylcholine (HPC) and egg lecithin (EPC) were used as carrier materials and, the effects of carrier composition on the product morphology and drug release behavior were investigated. When the mass ratio of Zein/HPC/ EPC was 7/2/1, the AMF loaded particles were spherical shape and sub-micron sized around 400 nm, with a drug load of 4.3±0.3 w% and entrapment efficacy of 87.8±1.8%. The in vitro drug release assay showed that adding EPC in the wall materials could improve the dispersion stability of the released AMF in an aqueous medium, and the introduction of HPC could accelerate the drug release speed.

Results:

MTT assay demonstrated that AMF-loaded micron particles have an improved inhibitory effect on A375 cells, whose IC50 was 37.39μg/ml, compared with that of free AMF(130.2μg/ml).

Conclusion:

It proved that the AMF loaded sub-micron particles prepared by SAS were a prospective strategy to improve the antitumor activity of AMF, and possibly promote the clinical use of AMF preparations.

Assessment of Exenatide loaded Biotinylated Trimethylated Chitosan/HP-55 Nanoparticles

BACKGROUND

Exenatide (EXE) is an anti-hyperglycemic agent approved for treating type 2 diabetes by the Food and Drug Administration (FDA). However, twice-daily injection of exenatide inconveniences most patients.

OBJECTIVE

In this study, biotinylated trimethylated chitosan (Bio-TMC) based nanoparticles were proposed to promote oral absorption of exenatide. Realizing the oral administration of exenatide is very important to alleviate patient suffering and improve patient compliance.

METHODS

Bio-TMC was synthesized, and the chemical structure was characterized by Fourier transform infrared (FT-IR) spectroscopy and 1H NMR spectroscopy. Nanoparticles were prepared through polyelectrolyte interaction in the presence of sodium tripolyphosphate (TPP) and Hydroxypropyl methylcellulose phthalate (HP-55). The formulations were physically and chemically characterized. In vitro release was investigated in different pH media. In vivo antidiabetic activities of biotin modified and non-biotin modified chitosan were evaluated in db/db mice.

RESULTS

EXE-loaded Bio-TMC/HP-55 nanoparticles were spherical in shape with a mean diameter of 156.2 nm and zeta potential of +11.3 mV. The drug loading efficiency and loading contents were 52.38% and 2.08%, respectively. In vitro release revealed that EXE-loaded Bio-TMC/HP-55 nanoparticles were released faster in pH 1.2 than pH 6.8 (63.71% vs. 50.12%), indicating that nanoparticles had enteric characteristics. Antidiabetic activity study revealed that after oral administration to diabetic mice, the relative pharmacological bioavailability (FPharm%) of the biotin modified nanoparticles was found to be 1.27-fold higher compared with the unmodified ones and the hypoglycemic effect was also better.

CONCLUSION

Bio-TMC/HP-55 nanoparticles are feasible as oral drug carriers of exenatide and have the potential to be extended to other drugs that are not readily oral, such as monoclonal antibodies, vaccines, genes, etc., thus, this would be beneficial for pharmaceutical industries. Further research will focus on the biodistribution of Bio-TMC/HP-55 nanoparticles after oral administration.

Simvastatin treatment varies the radiation response of human breast cells in 2D or 3D culture

Background Statins inhibit the cholesterol biosynthesis and are used as cholesterol-lowering agents in fat-metabolism disorders. Furthermore, several studies state that statins have supportive functions in breast cancer treatment. Therefore, simvastatin (SVA) as a potential radiosensitizer should be investigated on the basis of human breast cells. Methods First, an optimal concentration of SVA for normal (MCF10A) and cancer (MCF-7) cells was identified via growth and cytotoxicity assays that, according to the definition of a radiosensitizer in the narrower sense, enhances the effect of radiation therapy but has no cytotoxic effect. Next, in combination with radiation SVA's influence on DNA repair capacity and clonogenic survival in 2D and 3D was determined. Furthermore cell cycle distribution, expression of survivin and connective tissue growth factor (CTGF) as well as ERK1 map kinase were analysed. Results 1 μM SVA was identified as highest concentration without an influence on cell growth and cytotoxicity and was used for further analyses. In terms of early and residual γH2AX-foci, SVA affected the number of foci in both cell lines with or without irradiation. Different radiation responses were detected in 2D and 3D culture conditions. During the 2D cultivation, a radiosensitizing effect within the clonogenic survival was observable, but not in 3D. Conclusion The present study suggests that SVA may have potential for radiosensitization. Therefore, it is important to further investigate the role of SVA in relation to the extent of radiosensitization and how it could be used to positively influence the therapy of breast cancer or other entities.

Capsaicin-Loaded Chitosan Nanocapsules for wtCFTR-mRNA Delivery to a Cystic Fibrosis Cell Line

Cystic fibrosis (CF), a lethal hereditary disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene coding for an epithelial chloride channel, is characterized by an imbalanced homeostasis of ion and water transports in secretory epithelia. As the disease is single-gene based, transcript therapy using therapeutic mRNA is a promising concept of treatment in order to correct many aspects of the fatal pathology on a cellular level. Hence, we developed chitosan nanocapsules surface-loaded with wtCFTR-mRNA to restore CFTR function. Furthermore, we loaded the nanocapsules with capsaicin, aiming to enhance the overall efficiency of transcript therapy by reducing sodium hyperabsorption by the epithelial sodium channel (ENaC). Dynamic light scattering with non-invasive back scattering (DLS-NIBS) revealed nanocapsules with an average hydrodynamic diameter of ~200 nm and a Zeta potential of ~+60 mV. The results of DLS-NIBS measurements were confirmed by asymmetric flow field-flow fractionation (AF4) with multidetection, while transmission electron microscopy (TEM) images confirmed the spherical morphology and size range. After stability measurements showed that the nanocapsules were highly stable in cell culture transfection medium, and cytotoxicity was ruled out, transfection experiments were performed with the CF cell line CFBE41o-. Finally, transepithelial measurements with a new state-of-the-art Ussing chamber confirmed successfully restored CFTR function in transfected cells. This study demonstrates that CS nanocapsules as a natural and non-toxic delivery system for mRNA to target cells could effectively replace risky vectors for gene delivery. The nanocapsules are not only suitable as a transcript therapy for treatment of CF, but open aspiring possibilities for safe gene delivery in general.

Chitosan-Based Microparticles Enhance Ellagic Acid's Colon Targeting and Proapoptotic Activity

This study aimed at improving the targeting and cytotoxic effect of ellagic acid (EA) on colon cancer cells. EA was encapsulated in chitosan (CHIT) polymers then coated by eudragit S100 (ES100) microparticles. The release of EA double-coated microparticles (MPs) was tested at simulative pH values. Maximum release was observed at 24 h and pH 7.4. The cytotoxicity of EA MPs on HCT 116 colon cancer cells was synergistically improved as compared with raw EA. Cell-cycle analysis by flow cytometry suggested enhanced G2-M phase colon cancer cell accumulation. In addition, a significantly higher cell fraction was observed in the pre-G phase, which highlighted the enhancement of the proapoptotic activity of EA formulated in the double-coat mixture. Annexin-V staining was used for substantiation of the observed cell-death-inducing activity. Cell fractions were significantly increased in early, late, and total cell death. This was backed by high elevation in cellular content of caspase 3. Effectiveness of the double-coated EA to target colonic tissues was confirmed using real-time iohexol dye X-ray radiography. In conclusion, CHIT loaded with EA and coated with ES100 formula exhibits improved colon targeting as well as enhanced cytotoxic and proapoptotic activity against HCT 116 colon cancer when compared with the administration of raw EA.

The Enhanced Cytotoxic and Pro-Apoptotic Effects of Optimized Simvastatin-Loaded Emulsomes on MCF-7 Breast Cancer Cells

Statins, including simvastatin (SMV), are commonly used for the control of hyperlipidaemia and have also proven therapeutic and preventative effects in cardiovascular diseases. Besides that, there is an emerging interest in their use as antineoplastic drugs as demonstrated by different studies showing their cytotoxic activity against different cancer cells. In this study, SMV-loaded emulsomes (SMV-EMLs) were formulated and evaluated for their cytotoxic activity in MCF-7 breast cancer cells. The emulsomes were prepared using a modified thin-film hydration technique. A Box-Behnken model was used to investigate the impact of formulation conditions on vesicle size and drug entrapment. The optimized formulation showed a spherical shape with a vesicle size of 112.42 ± 2.1 nm and an entrapment efficiency of 94.34 ± 1.11%. Assessment of cytotoxic activities indicated that the optimized SMV-EMLs formula exhibited significantly lower half maximal inhibitory concentration (IC50) against MCF-7 cells. Cell cycle analysis indicated the accumulation of cells in the G2-M phase as well as increased cell fraction in the pre-G1 phase, suggesting an enhancement of anti-apoptotic activity of SMV. The staining of cells with Annex V revealed an increase in early and late apoptosis, in line with the increased cellular content of caspase-3 and Bax. In addition, the mitochondrial membrane potential (MMP) was significantly decreased. In conclusion, SMV-EMLs demonstrated superior cell death-inducing activity against MCF-7 cells compared to pure SMV. This is mediated, at least in part, by enhanced pro-apoptotic activity and MMP modulation of SMV.