Synergistic Effect of Layered Double Hydroxides Nanodosage Form to Induce Apoptosis and Ferroptosis in Breast Cancer.

Background: Breast cancer is the most common cancer in women and one of the leading causes of cancer death worldwide. Ferroptosis, a promising mechanism of killing cancer cells, has become a research hotspot in cancer therapy. Simvastatin (SIM), as a potential new anti-breast cancer drug, has been shown to cause ferroptosis of cancer cells and inhibit breast cancer metastasis and recurrence. The purpose of this study is to develop a novel strategy boosting ferroptotic cascade for synergistic cancer therapy. Methods: In this paper, iron base form of layered double hydroxide supported simvastatin (LDHs-SIM) was synthesized by hydrothermal co-precipitation method. The characterization of LDHs-SIM were assessed by various analytical techniques, including ultraviolet-visible (UV-vis) spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and transmission electron microscopy (TEM). Biological activity, ferroptosis mechanism and biocompatibility were analyzed through in vivo and in vitro analysis, so as to evaluate its therapeutic effect on breast cancer. Results: The constructed LDHs-SIM nanosystem can not only release SIM through mevalonate (MVA) pathway, inhibit the expression of glutathione peroxidase 4 (GPX4), inhibit the expression of SLC7A11 and reduce the synthesis efficiency of GSH, but also promote the accumulation of Fe2+ in cells through the release of Fe3+, and increase the intracellular ROS content. In addition, LDHs-SIM nanosystem can induce apoptosis of breast cancer cells to a certain extent, and achieve the synergistic effect of apoptosis and ferroptosis. Conclusion: In the present study, we demonstrated that nanoparticles of layered double hydroxides (LDHs) loaded with simvastatin were more effective than a free drug at inhibiting breast cancer cell growth, In addition, superior anticancer therapeutic effects were achieved with little systemic toxicity, indicating that LDHs-SIM could serve as a safe and high-performance platform for ferroptosis-apoptosis combined anticancer therapy.

De novo dual functional 3D scaffold using computational simulation with controlled drug release.

A novel and facile synthesis is made of cotton-like three-dimensional (3D) fibrous scaffold containing spatiotemporally defined patterns of simvastatin (SIM) optimized for angiogenesis-coupled osteogenesis. Herein, we demonstrate the 3D fiber deposition mechanism in detail during the electrospinning process via computer simulation. The 3D fibrous scaffolds were functionalized with hydroxyapatite nanoparticles (HA - NPs) to induce the biomineralization process mimicking the natural apatite layer. The morphology, physiochemical properties, biomimetic mineralization, and drug release of the as-fabricated 3D fibrous scaffolds of simvastatin-loaded poly (ɛ-caprolactone) poly (glycerol-sebacate) hydroxyapatite nanoparticles (3D - PGHS) were investigated. The effects of simvastatin on the osteogenic differentiation of human mesenchymal stem cells (hMSCs) and angiogenesis in human umbilical vein endothelial cells (HUVECs) were assessed. The results showed that the 3D - PGHS both enhanced the expression of osteogenic markers including ALP, RUNX2, and COLA1 in hMSCs, and promoted the migration and tube formation of HUVECs. This finding demonstrates the potential of 3D scaffold-loaded SIM as a putative point-of-care therapy for tightly controlled tissue regeneration.

IAF, QGF, and QDF Peptides Exhibit Cholesterol-Lowering Activity through a Statin-like HMG-CoA Reductase Regulation Mechanism: In Silico and In Vitro Approach.

In this study, in silico approaches are employed to investigate the binding mechanism of peptides derived from cowpea ß-vignin and HMG-CoA reductase. With the obtained information, we designed synthetic peptides to evaluate their in vitro enzyme inhibitory activity. In vitro, the total protein extract and <3 kDa fraction, at 5000 µg, support this hypothesis (95% and 90% inhibition of HMG-CoA reductase, respectively). Ile-Ala-Phe, Gln-Gly-Phe, and Gln-Asp-Phe peptides were predicted to bind to the substrate binding site of HMGCR via HMG-CoAR. In silico, it was established that the mechanism of HMG-CoA reductase inhibition largely entailed mimicking the interactions of the decalin ring of simvastatin and via H-bonding; in vitro studies corroborated the predictions, whereby the HMG-CoA reductase activity was decreased by 69%, 77%, and 78%, respectively. Our results suggest that Ile-Ala-Phe, Gln-Gly-Phe, and Gln-Asp-Phe peptides derived from cowpea ß-vignin have the potential to lower cholesterol synthesis through a statin-like regulation mechanism.

Simvastatin induced ferroptosis for triple-negative breast cancer therapy.

Triple-negative breast cancer (TNBC), a management of aggressive breast cancer, remains an unmet medical challenge. Although a wave of efforts had spurred to design novel therapeutic method of TNBC, unpredictable prognosis with lacking effective therapeutic targets along with the resistance to apoptosis seriously limited survival benefits. Ferroptosis is a non-apoptotic form of cell death that is induced by excessive lipid peroxidation, which provide an innovative way to combat cancer. Emerging evidence suggests that ferroptosis plays an important role in the treatment of TNBC cells. Herein, a novel ferroptosis nanomedicine was prepared by loading simvastatin (SIM), a ferroptosis drug, into zwitterionic polymer coated magnetic nanoparticles (Fe3O4@PCBMA) to improve the therapeutic effect of TNBC. The as-obtained Fe3O4@PCBMA-SIM nanoparticles demonstrated more cytotoxicity against MDA-MB-231 than MCF-7 due to the higher expression of 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMGCR), which demonstrated that statins could effectively kill TNBC. Further experiments showed that SIM could inhibit the expression of HMGCR to downregulate the mevalonate (MVA) pathway and glutathione peroxidase 4 (GPX4), thereby inducing cancer cell ferroptosis. What's more, PCBMA endows Fe3O4@PCBMA longer blood circulation performance to enhance their accumulation at tumor sites. Given that Fe3O4 have proven for clinical applications by the U.S. Food and Drug Administration (FDA) and SIM could induce cancer cell ferroptosis, the developed Fe3O4@PCBMA-SIM nanosystem would have great potential in clinics for overcoming the drug resistance brought about by apoptotic drugs to cancer cells.

Co-delivery of simvastatin and demineralized bone matrix hierarchically from nanosheet-based supramolecular hydrogels for osteogenesis.

Supramolecular hydrogels are widely used as 3D scaffolds and delivery platforms in tissue engineering applications. However, hydrophobic therapeutic agents exhibit weak compatibility in hydrogel scaffolds along with aggregation and precipitation. Herein, simvastatin drugs used as BMP-2 stimulators are encapsulated into the layer space of LAPONITE® via electrostatic interactions and ion exchange efficiently, and supramolecular hydrogels could be fabricated with a self-healing, injectable and sustained drug release nature. Hydrogels encapsulated with 10 µg mL-1 simvastatin drug show good osteogenic differentiation in vitro. Moreover, the loading of demineralized bone matrix particles could enhance the capacity for osteogenesis via improving the expression of BMP-2 synergistically. The integrated hydrogels could be implanted into cranial defect sites for bone regeneration in vivo. This work provides the first demonstration of molecular and supramolecular engineering of hydrogels to load osteoinductive agents hierarchically for bone regeneration, contributing to the development of a brand-new strategy for dealing with compatibility between scaffolds and osteogenic agents.

Preparation and characterization of poly (lactic-co-glycolic acid) nanofibers containing simvastatin coated with hyaluronic acid for using in periodontal tissue engineering.

Periodontal diseases can lead to soft tissue defects. Tissue engineering can provide functional replacements for damaged tissues. Recently, electrospun nanofibers have attracted great interest for tissue engineering and drug delivery applications. This has been revealed that statins exhibit positive impacts on the proliferation and regeneration of periodontal tissues. Electrospun simvastatin loaded poly (lactic-co-glycolic acid) (SIM-PLGA-NF) were prepared using electrospinning technique. Optimal conditions for preparation of SIM-PLGA-NF (PLGA concentration of 30 wt%, voltage of 15 kV, and flow rate of 1.5 ml h-1 ) were identified using a 23 factorial design. The optimized SIM-PLGA-NFs (diameter of 640.2 ± 32.5 nm and simvastatin entrapment efficacy of 99.6 ± 1.5%) were surface modified with 1% w/v hyaluronic acid solution (1%HA- SIM-PLGA-NF) to improve their compatibility with fibroblasts and potential application as a periodontal tissue engineering scaffold. HA-SIM-PLGA NFs were analyzed using SEM, FTIR, and XRD. 1%HA-SIM-PLGA-NF had uniform, bead-free and interwoven morphology, which is similar to the extracellular matrix. The mechanical performance of SIM-PLGA-NFs and release profile of simvastatin from these nanofibers have been also greatly improved after coating with HA. In vitro cellular tests showed that the proliferation, adhesion, and differentiation of fibroblast cells positively enhanced on the surface of 1%HA- SIM-PLGA-NF. These results demonstrate the potential application of 1%HA-SIM-PLGA-NFs as a scaffold for periodontal tissue engineering.

Fixed Dose Single Tablet Formulation with Differential Release of Amlodipine Besylate and Simvastatin and Its Pharmacokinetic Profile: QbD and Risk Assessment Approach.

PURPOSE: A differential release fixed dose matrix tablet of amlodipine besylate (AML-B) and simvastatin (SIM) was formulated to enhance patient compliance. MATERIAL AND METHOD: In the first phase, release controlling parameters of AML-B and SIM granules were identified and in the second phase a fixed dose AML-B and SIM tablet formulation was prepared and optimized for a differential release of the drugs using a quality by design (QbD) and risk assessment approach. A validated HPLC method was employed for simultaneous determination of AML-B and SIM for FDC formulation. A pharmacokinetics of the above drugs was studied in healthy dogs in the third phase. RESULTS: In QbD-based optimized formulation, Eudragit® RSPO-dicalcium phosphate (DCP) blend controlled the release of AML-B over 8 h, though this diffusion-controlled release assumed first order kinetics. DCP and Eudragit® RS 100 also retarded release of SIM causing SIM release over 8 h after AML-B release from the optimized FDC tablet formulation. The HPLC retention times of AML-B and SIM were 2.10 and 15.52 min, respectively. Linearity for AML-B was 5.0-50 ng/mL and 0.01-2.0 µg/mL for SIM with percent recoveries of 92.85-101.53% and 94.51-117.75% for AML-B and SIM. AUC0-∞ of AML-B was increased 3 fold, while AUC0-∞ of SIM was decreased 2 fold. The tmax values for AML-B and SIM were 12 and 6 h, respectively. AML-B was absorbed without any lag time (tlag) while tlag was 6.33 ± 0.81 h for SIM, thus met the study objective. CONCLUSION: The pharmacokinetic study showed an immediate absorption of AML-B while that of SIM was withheld for 6 h, close to the desired delay time of 8 h.

Assessing the Interactions of Statins with Human Adenylate Kinase Isoenzyme 1: Fluorescence and Enzyme Kinetic Studies.

Statins are the most effective cholesterol-lowering drugs. They also exert many pleiotropic effects, including anti-cancer and cardio- and neuro-protective. Numerous nano-sized drug delivery systems were developed to enhance the therapeutic potential of statins. Studies on possible interactions between statins and human proteins could provide a deeper insight into the pleiotropic and adverse effects of these drugs. Adenylate kinase (AK) was found to regulate HDL endocytosis, cellular metabolism, cardiovascular function and neurodegeneration. In this work, we investigated interactions between human adenylate kinase isoenzyme 1 (hAK1) and atorvastatin (AVS), fluvastatin (FVS), pravastatin (PVS), rosuvastatin (RVS) and simvastatin (SVS) with fluorescence spectroscopy. The tested statins quenched the intrinsic fluorescence of hAK1 by creating stable hAK1-statin complexes with the binding constants of the order of 104 M-1. The enzyme kinetic studies revealed that statins inhibited hAK1 with significantly different efficiencies, in a noncompetitive manner. Simvastatin inhibited hAK1 with the highest yield comparable to that reported for diadenosine pentaphosphate, the only known hAK1 inhibitor. The determined AK sensitivity to statins differed markedly between short and long type AKs, suggesting an essential role of the LID domain in the AK inhibition. Our studies might open new horizons for the development of new modulators of short type AKs.

Hierarchically porous calcium-silicon nanosphere-enabled co-delivery of microRNA-210 and simvastatin for bone regeneration.

The regenerative repair of large bone defects is a major problem in orthopedics and clinical medicine. The key problem is the lack of ability of existing bone graft materials to promote osteogenesis and angiogenesis. Previous studies have shown that the osteogenic or angiogenic abilities of these materials could be significantly improved by adding miRNA or small-molecule drugs to bone graft materials; however, the synergistic effect arising from this combination is not clear. Therefore, we proposed to construct a dual drug delivery system that could simultaneously achieve the co-encapsulation and co-delivery of miRNA and small-molecule drugs to explore the effect of a dual drug delivery system on bone repair. In this study, we constructed dual-sized pore structure calcium-silicon nanospheres (DPNPs) and achieved the co-encapsulation of miR-210, angiogenic gene drugs, and simvastatin (Siv), a small-molecule osteogenic drug, through metal-ion coordination and physical adsorption. In vitro and in vivo osteogenic and angiogenic experiments showed that the dual drug delivery system (Siv/DPNP/miR-210) exhibited better properties than those of the individual unloaded and single drug-loaded systems and could significantly accelerate the process of bone repair, which provides a novel strategy for the regeneration and repair of bone defects.

Surface modification of the simvastatin factor-loaded silk fibroin promotes the healing of rotator cuff injury through ß-catenin signaling.

Rupture of the rotator cuff is a common injury of the shoulder joint in sports professionals. In addition, research on repair of the rotator cuff has gained popularity over the recent years. Given the high rate of re-tear after surgery, it is necessary to design and prepare biodegradable materials with good mechanical properties, for the management of the condition. Consequently, the present study conducted surface modification of the simvastatin factor-loaded silk fibroin for the repair of chronic rotator cuff injury in SD rats. The in vitro experiments were analyzed through scanning electron microscopy and the water contact angle. Additionally, the CCK-8 assay was used to observe the effect of the intervention on the proliferation of BMSCs. Moreover, the osteogenic differentiation of BMSCs was detected through the ALP and ARS assays while the expression of osteogenic genes was examined using qRT-PCR and Western blot analysis. Furthermore, a model for repairing chronic rotator cuff tears in SD rats was established in vivo. Thereafter, rotator cuff repair and healing were evaluated through HE staining while Masson and Sirius staining was used to detect the collagen formation ratio. Additionally, the study analyzed the mechanism underlying the effect of simvastatin-loaded silk fibroin. The results showed that the simvastatin-loaded silk fibroin membrane had better biocompatibility and the in vitro experiments confirmed that it could promote the proliferation and osteogenic differentiation of BMSCs. In addition, the in vivo HE staining experiments similarly confirmed that it could enhance tendon bone healing and alleviate inflammation in chronic rotator cuff injuries. On the other hand, Masson and Sirius staining showed that the simvastatin-loaded silk fibroin could promote the formation of collagen. Further analysis also revealed that it could promote the osteogenic differentiation of BMSCs by activating the ß-catenin signaling pathway. In general, these findings suggested that surface modification of the simvastatin factor-loaded silk fibroin was a potential means of improving the healing of rotator cuff injuries and can be implemented in clinical practice in future.

Simvastatin nanosuspensions prepared using a combination of pH-sensitive and timed-release approaches for potential treatment of colorectal cancer.

A dual pH- and time-dependent polymeric coated capsule was developed to achieve the site specificity of simvastatin (SIM) release in the colon. To improve the SIM solubility, soluplus-based nanosuspension of the drug were prepared by applying the anti-solvent crystallization technique; this was then followed by lyophilization. Particle size, polydispersity index, and saturation solubility were evaluated. The optimized nanosuspension was combined with SLS and freeze-dried before filling into hard gelatin capsules. Drug release characteristics of the coated capsules were studied in HCl 0.1 N, the phosphate buffers 6.8 and 7.4, and the simulated colonic fluid (pH 6.8). The in-vitro cytotoxic effects of SIM nanoparticles against HT29 cells were then evaluated using the MTT assay. The prepared nanoparticles were spherical with a mean size of 261.66 nm, the zeta potential of -18.20 and the dissolution efficiency of 59.71%. X-ray diffraction and differential scanning calorimetry studies showed that the nanosizing technique transformed the crystalline drug into the more soluble amorphous form. The coated capsules had no release in the gastric media, providing the specific delivery of SIM in the colon. The cytotoxic effect of the SIM nanoparticles was significantly increased, as compared to the free SIM. The findings, therefore, showed that the coated capsules using the two polymers of ethyl cellulose and Eudragit S100 could be suitable for the colon target delivery of SIM.

TPGS2k-PLGA composite nanoparticles by depleting lipid rafts in colon cancer cells for overcoming drug resistance.

Recently, studies showed that the drug-resistant cell membranes have formed high-density lipid rafts regions; traditional targeted drug delivery systems can hardly break through the hard shell and deliver drugs to drug-resistant cells. Here, α-tocopherol polyethylene glycol 2000 succinate (TPGS2k) was successfully synthesized and used to modify poly (lactic-glycolic acid) nanoparticles co-loaded with doxorubicin (DOX) and simvastatin (SV) (SV/DOX@TPGS2k-PLGA NPs). The purpose of this study is to explore the synergistic effect between SV consuming cholesterol in lipid rafts and directly down-regulating P-gp expression on the intracellular drugs retention. The research highlights these nanoparticles interrupted lipid rafts (cholesterol-rich domains, where P-gp is often located), which inhibited drug efflux by down-regulating P-gp, promoted the mitochondria apoptosis and made SW620/AD300 cells (DOX-resistant colon cancer cell line) re-sensitized to DOX. Therefore, the carrier can become a promising SV-based nano-delivery system with depleting cholesterol in lipid rafts to reverse drug resistance.

Hyaluronic acid-coated polymeric micelles with hydrogen peroxide scavenging to encapsulate statins for alleviating atherosclerosis.

Inflammation and oxidative stress are two major factors that are involved in the pathogenesis of atherosclerosis. A smart drug delivery system that responds to the oxidative microenvironment of atherosclerotic plaques was constructed in the present study. Simvastatin (SIM)-loaded biodegradable polymeric micelles were constructed from hyaluronic acid (HA)-coated poly(ethylene glycol)-poly(tyrosine-ethyl oxalyl) (PEG-Ptyr-EO) for the purpose of simultaneously inhibiting macrophages and decreasing the level of reactive oxygen species (ROS) to treat atherosclerosis. HA coating endows the micelle system the ability of targeting CD44-positive inflammatory macrophages. Owing to the ROS-responsive nature of PEG-Ptyr-EO, the micelles can not only be degraded by enzymes, but also consumes ROS by itself at the pathologic sites, upon which the accumulation of pro-inflammatory macrophages is effectively suppressed and oxidative stress is alleviated. Consequently, the cellular uptake experiment demonstrated that SIM-loaded HA-coated micelles can be effectively internalized by LPS-induced RAW264.7 cells and showed high cytotoxicity against the cells, but low cytotoxicity against LO2 cells. In mouse models of atherosclerosis, intravenously SIM-loaded HA-coated micelles can effectively reduce plaque content of cholesterol, resulting in remarkable therapeutic effects. In conclusion, the SIM-loaded micelle system provides a promising and innovative option against atherosclerosis.

Simvastatin-Nicotinamide Co-Crystals: Formation, Pharmaceutical Characterization and in vivo Profile.

PURPOSE: To enhance the solubility and dissolution profile of simvastatin (SIM) through co-crystallization with varying ratios of nicotinamide (NIC) using various co-methods. MATERIALS AND METHODS: Twelve SIM:NIC co-crystal formulations (F01-F12) were prepared using dry grinding, slurry, liquid-assisted grinding, and solvent-evaporation methods, and their properties compared. Optimized formulations were selected on the basis of dissolution profiles and solubility for in vivo studies. The angle of repose, Carr Index and Hausner ratio were calculated to evaluate flow properties. Differential light scattering (DLS) was used to estimate particle-size distribution. Scanning electron microscopy (SEM) was employed to evaluate surface morphology. Thermal analyses and Fourier-transform infrared (FTIR) spectroscopy were used to determine the ranges of thermal stability and physical interaction of formulated co-crystals. X-ray powder diffraction (XPD) spectroscopy was used to determine the crystalline nature. Solubility and dissolution studies were undertaken to determine in vitro drug-release behaviors. RESULTS: Micromeritic analyses revealed the good flow properties of formulated co-crystals. DLS showed the particle size of co-crystals to be in the nanometer range. SEM revealed that the co-crystals were regular cubes. Thermal studies showed the stability of co-crystals at >300°C. FTIR spectroscopy revealed minor shifts of various peaks. XPD spectroscopy demonstrated co-crystal formation. The formulations exhibited an improved dissolution profile with marked improvements in solubility. In vivo studies showed a 2.4-fold increase in Cmax whereas total AUC(0-∞) was increased 4.75-fold as compared with that of SIM tablets. CONCLUSION: Co-crystallization with NIC improved the solubility and dissolution profile and, hence, the bioavailability of the poorly water-soluble drug SIM.

Preparation and characterization of polypills containing aspirin and simvastatin using 3D printing technology for the prevention of cardiovascular diseases.

Three-dimensional (3D) printing has become a promising manufacturing technique for pharmaceutical products. Fused deposition modeling (FDM) is the most affordable printing technology. But this technique has two major drawbacks: limited drug-loading capacity and the stability of thermolabile drugs. So, other techniques such as melt casting could be associated with FDM to overcome these limitations. In the melt casting method, the drug is mixed with a molten polymer and is poured in the mold and allowed to solidify. The present study for the first time describes the preparation of a multi-compartment polypill permits the physical separation of incompatible drugs by combination of FDM and melt casting techniques. A two-compartment polypill was made using FDM by Eudragit® L100-55 and simultaneously its compartments were filled by aspirin and simvastatin containing molten PEG 6000. Simultaneous usage of FDM and melt casting techniques could increase the drug-loading capacity of 3D-printed polypills. The low temperatures used in melt casting and the absence of solvent in this method would warrant the integrity of polypills, the complete separation of incompatible drugs, and their stability. The prepared polypills showed good uniformity in drug content which confirms the precision of FDM and melt casting techniques. Drug interaction was investigated before and after the accelerated stability test using DSC, which showed that 3D-printed polypills successfully preserved drugs from the interaction. For the first time, this study demonstrates the feasibility of the combination of FDM and melt casting techniques as an innovative platform for CVD polypills production.

Drug-eluting PCL/graphene oxide nanocomposite scaffolds for enhanced osteogenic differentiation of mesenchymal stem cells.

Recently, drug-eluting nanofibrous scaffolds have attracted a great attention to enhance the cell differentiation through biomimicking the extracellular matrix (ECM) in regenerative medicine. In this study, electrospun nanocomposite polycaprolactone (PCL)-based scaffolds containing synthesized graphene oxide (GO) nanosheets and osteogenic drugs, i.e. dexamethasone and simvastatin were fabricated. The physicochemical and surface properties of the scaffolds were investigated through FTIR, wettability, pH, and drug release studies. The cell viability, differentiation, and biomineralization were studied on mesenchymal stem cells (MSCs) by Alamar Blue, alkaline phosphatase (ALP) activity, and Alizarin Red-S staining, respectively. Uniformly distributed GO (thickness < 1 nm) in PCL nanofibers was observed by electron microscopy. It was revealed that the addition of GO and the drugs improved the hydrophilicity, cell viability, and osteogenic differentiation, in addition to pH changes, in comparison with PCL scaffolds. Despite the notable reduction in the cell viability, significant differentiation was revealed by ALP assay on PCL/GO-Dex scaffolds. Noteworthy, a twofold increase in the osteogenic differentiation was observed in comparison with the cells cultured in osteogenic differentiation medium, while a significant biomineralization was observed. The results of this study indicate the synergistic effect of GO and dexamethasone on improving osteogenic differentiation of drug-eluting nanocomposite scaffolds in bone tissue engineering applications.

Experimental, Thermodynamic, and Molecular Modeling Evaluation of Amorphous Simvastatin-Poly(vinylpyrrolidone) Solid Dispersions.

A crucial step for the selection of proper amorphous solid dispersion (ASD) matrix carriers is the in-depth assessment of drug/polymer physicochemical properties. In this context, the present study extends the work of previously published attempts by evaluating the formation of simvastatin (SIM)-poly(vinylpyrrolidone) (PVP) ASDs with the aid of thermodynamic and molecular modeling. Specifically, the implementation of both Flory-Huggins lattice theory and molecular dynamics (MD) simulations was able to predict the miscibility between the two components (a finding that was experimentally verified via differential scanning calorimetry (DSC) and hot stage polarized microscopy), while a complete temperature-concentration phase-transition profile was constructed, leading to the identification of the thermodynamically metastable and unstable ASD zones. Furthermore, as in the case of previously published reports, the analysis of the ASDs via Fourier transform infrared spectroscopy did not clarify the type and extent of observed molecular interactions. Hence, in the present study, a computer-based MD simulation model was developed for the first time in order to gain an insight into the properties of the observed interactions. MD amorphous assemblies of SIM, PVP, and their mixtures were initially developed, and the calculated glass transition temperatures were in close agreement with experimentally obtained results, indicating that the developed models could be considered as realistic representations of the actual systems. Furthermore, molecular interactions evaluation via radial distribution function and radius of gyration analysis revealed that increasing SIM content results in a significant PVP chain shrinkage, which eventually leads to SIM-SIM amorphous intermolecular interactions, leading to the formation of amorphous drug zones. Finally, MD-based results were experimentally verified via DSC.

In Situ Gel Loaded with Chitosan-Coated Simvastatin Nanoparticles: Promising Delivery for Effective Anti-Proliferative Activity against Tongue Carcinoma.

The goal of this study is to develop optimized chitosan-coated Simvastatin (SIM) nanoparticles (NPs) loaded in an in situ gel (ISG) formulation via a face-centered central composite design (FCCCD). Coated SIM-NPs were doped with Quercetin (QRC) using a modified nanoprecipitation method. The concentrations of poloxamer 188 (A) and chitosan (B) at five different levels, plus/minus alpha (+1.414 and -1.414: axial points), plus/minus 1 (factorial points) and the center point were optimized for particle size (PS-Y1), entrapment efficacy (EE-Y2) and stability index (SI-Y3). Based on the desirability approach, a formulation containing poloxamer 188 0.24% and chitosan 0.43% renders the prerequisites of optimum formulation for preparing SIM-QRC NP-loaded ISG. Scanning microscopy showed spherical SIM-NPs, indicating monodispersity in the range of 0.50 ± 0.04 nm with a charge of +32.42 mV. The optimized formulation indicated the highest EE 79.67% and better stability at 4 °C. Drug release from SIM-QRC NP-loaded ISG was slower to plateau by up to 96 h and, at the end of 168 h, only 65.12% of SIM was released in a more controlled manner in comparison to SIM-QRC NPs and plain SIM. ISG formulation showed a considerable increase in apoptosis occurrence through caspase-3 mediation and it also enhanced the tumor suppressor protein levels. Enhanced biological activity of SIM was observed due to QRC enabling promising drug and polymer synergistic interaction. The proposed formulation can provide a breakthrough in localized therapy, overcoming the potential drawbacks of systemic chemotherapy for tongue carcinoma.

Stent coating by electrospinning with chitosan/poly-cyclodextrin based nanofibers loaded with simvastatin for restenosis prevention.

The main cause of failure of angioplasty stenting is restenosis due to neointimal hyperplasia, a too high proliferation of smooth muscle cells (SMC). The local and sustained delivery of selective pleiotropic drugs to limit SMC proliferation seems to be the hopeful solution to minimize this post surgery complication. The aim of this study is to develop a stent covered by nanofibers (NFs) produced by electrospinning, loaded with simvastatin (SV), a drug commonly used for restenosis prevention. NFs were prepared from the electrospinning of a solution containing SV and a mixture of chitosan (cationic) and ß-cyclodextrin (CD) polymer (anionic) which form together a polyelectrolyte complex that makes up the NFs matrix. First, the SV/CD interactions were studied by phase solubility diagram, DRX and DSC. The electrospinning process was then optimized to cover a self-expandable NiTiNOL stent and the mechanical resistance of the NFs sheath upon its introduction inside the delivery catheter was considered, using a crimper apparatus. The morphology, coating thicknesses and diameters of nanofibers were studied by scanning electron microscopy. The SV loading rates on the stents were controlled by the electrospinning time, and the presence of SV in the NFs was confirmed by FTIR. NFs stability in PBS pH 7.4 buffer could be improved after thermal post-treatment of NFs and in vitro release of SV in dynamic conditions demonstrated that the release profiles were influenced by the presence of CD polymer in NFs and by the thickness of the NFs sheath. Finally, a covered stent delivering 3 µg/mm2 of SV within 6 h was obtained, whose efficiency will be investigated in a further in vivo study.

Inverse screening of Simvastatin kinase targets from glioblastoma druggable kinome.

The statin drug Simvastatin is a HMG-CoA reductase inhibitor that has been widely used to lower blood lipid. However, the drug is clinically observed to reposition a significant suppressing potency on glioblastoma (GBM) by unexpectedly targeting diverse kinase pathways involved in GBM tumorigensis. Here, an inverse screening strategy is described to discover potential kinase targets of Simvastatin. Various human protein kinases implicated in GBM are enriched to define a druggable kinome; the binding behavior of Simvastatin to the kinome is profiled systematically via an integrative computational approach, from which most kinases have only low or moderate binding potency to Simvastatin, while only few are identified as promising kinase hits. It is revealed that Simvastatin can potentially interact with certain known targets or key regulators of GBM such as ErbB, c-Src and FGFR signaling pathways, but exhibit low affinity to the well-established GBM target of PI3K/Akt/mTOR pathway. Further assays determine that Simvastatin can inhibit kinase hits EGFR, MET, SRC and HER2 at nanomolar level, which are comparable with those of cognate kinase inhibitors. Structural analyses reveal that the sophisticated T790 M gatekeeper mutation can considerably reduce Simvastatin sensitivity to EGFR by inducing the ligand change between different binding modes.