Red Blood Cell-Hitchhiking Delivery of Simvastatin to Relieve Acute Respiratory Distress Syndrome

Purpose

The purpose of this study is to address the high mortality and poor prognosis associated with Acute Respiratory Distress Syndrome (ARDS), conditions characterized by acute and progressive respiratory failure. The primary goal was to prolong drug circulation time, increase drug accumulation in the lungs, and minimize drug-related side effects.

Methods

Simvastatin (SIM) was used as the model drug in this study. Employing a red blood cell surface-loaded nanoparticle drug delivery technique, pH-responsive cationic nanoparticles loaded with SIM were non-covalently adsorbed onto the surface of red blood cells (RBC), creating a novel drug delivery system (RBC@SIM-PEI-PPNPs).

Results

The RBC@SIM-PEI-PPNPs delivery system effectively extended the drug's circulation time, providing an extended therapeutic window. Additionally, this method substantially improved the targeted accumulation of SIM in lung tissues, thereby enhancing the drug's efficacy in treating ARDS and impeding its progression to ARDS. Crucially, the system showed a reduced risk of adverse drug reactions.

Conclusion

RBC@SIM-PEI-PPNPs demonstrates promise in ARDS and ARDS treatment. This innovative approach successfully overcomes the limitations associated with SIM's poor solubility and low bioavailability, resulting in improved therapeutic outcomes and fewer drug-related side effects. This research holds significant clinical implications and highlights its potential for broader application in drug delivery and lung disease treatment.

Molecular Simulation Studies of Pharmaceutical Pollutant Removal (Rosuvastatin and Simvastatin) Using Novel Modified-MOF Nanostructures (UIO-66, UIO-66/Chitosan, and UIO-66/Oxidized Chitosan)

The ubiquitous presence of pharmaceutical pollutants in the environment significantly threatens human health and aquatic ecosystems. Conventional wastewater treatment processes often fall short of effectively removing these emerging contaminants. Therefore, the development of high-performance adsorbents is crucial for environmental remediation. This research utilizes molecular simulation to explore the potential of novel modified metal-organic frameworks (MOFs) in pharmaceutical pollutant removal, paving the way for the design of efficient wastewater treatment strategies. Utilizing UIO-66, a robust MOF, as the base material, we developed UIO-66 functionalized with chitosan (CHI) and oxidized chitosan (OCHI). These modified MOFs' physical and chemical properties were first investigated through various characterization techniques. Subsequently, molecular dynamics simulation (MDS) and Monte Carlo simulation (MCS) were employed to elucidate the adsorption mechanisms of rosuvastatin (ROSU) and simvastatin (SIMV), two prevalent pharmaceutical pollutants, onto these nanostructures. MCS calculations demonstrated a significant enhancement in the adsorption energy by incorporating CHI and OCHI into UIO-66. This increased ROSU from -14,522 to -16,459 kcal/mol and SIMV from -17,652 to -21,207 kcal/mol. Moreover, MDS reveals ROSU rejection rates in neat UIO-66 to be at 40%, rising to 60 and 70% with CHI and OCHI. Accumulation rates increase from 4 Å in UIO-66 to 6 and 9 Å in UIO-CHI and UIO-OCHI. Concentration analysis shows SIMV rejection surges from 50 to 90%, with accumulation rates increasing from 6 to 11 Å with CHI and OCHI in UIO-66. Functionalizing UIO-66 with CHI and OCHI significantly enhanced the adsorption capacity and selectivity for ROSU and SIMV. Abundant hydroxyl and amino groups facilitated strong interactions, improving performance over that of unmodified UIO-66. Surface functionalization plays a vital role in customizing the MOFs for pharmaceutical pollutant removal. These insights guide next-gen adsorbent development, offering high efficiency and selectivity for wastewater treatment.

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.

Solid self-emulsifying casein carrier for the improvement on the oral bioavailability of simvastatin

Simvastatin (SV) is a statin drug that can effectively control cholesterol and prevent cardiovascular diseases. However, SV is water-insoluble, and poor oral bioavailability (<5 %). Solid self-emulsifying carrier system is more stable than liquid emulsions, facilitating to improve the solubility and bioavailability of poorly soluble drugs. In the present study, a solid self-emulsifying carrier stabilized by casein (Cas-SSE) was successfully used to load SV to improve its solubility in water, by formulation selection and emulsification process optimization. Compared with oral tablets, the release of SV from Cas-SSE was significantly enhanced in artificial intestinal fluid. Furthermore, everted gut sac experiments indicated some water-soluble dispersing agents such as hydroxyethyl starch (HES), were not conducive to drug absorption. Pharmacokinetic studies suggested Cas-SSE without dispersing agent has much higher relative bioavailability (184.1 % of SV and 284.5 % of simvastatin acid) than SV tablet. The present work suggests Cas-SSE is a promising drug delivery platform with good biocompatibility for improving oral bioavailability of poorly water-soluble drugs.

Fabrication and characterization of a multi-functional GBR membrane of gelatin-chitosan for osteogenesis and angiogenesis

Guided bone regeneration (GBR) membranes are widely used to treat bone defects. In this study, sequential electrospinning and electrospraying techniques were used to prepare a dual-layer GBR membrane composed of gelatin (Gel) and chitosan (CS) containing simvastatin (Sim)-loaded poly(lactic-co-glycolic acid) (PLGA) microspheres (Sim@PLGA/Gel-CS). As a GBR membrane, Sim@PLGA/Gel-CS could act as a barrier to prevent soft tissue from occupying regions of bone tissue. Furthermore, compared with traditional GBR membranes, Sim@PLGA/Gel-CS played an active role on stimulating osteogenesis and angiogenesis. Determination of the physical, chemical, and biological properties of Sim@PLGA/Gel-CS membranes revealed uniform sizes of the nanofibers and microspheres and appropriate morphologies. Fourier-transform infrared spectroscopy was used to characterize the interactions between Sim@PLGA/Gel-CS molecules and the increase in the number of amide groups in crosslinked membranes. The thermal stability and tensile strength of the membranes increased after N-(3-dimethylaminopropyl)-N9- ethylcarbodiimide/N-hydroxysuccinimide crosslinking. The increased fiber density of the barrier layer decreased fibroblast migration compared with that in the osteogenic layer. Osteogenic function was indicated by the increased alkaline phosphatase activity, calcium deposition, and neovascularization. In conclusion, the multifunctional effects of Sim@PLGA/Gel-CS on the barrier and bone microenvironment were achieved via its dual-layer structure and simvastatin coating. Sim@PLGA/Gel-CS has potential applications in bone tissue regeneration.

The Development of Thermoresponsive Polymeric Simvastatin Prodrug for the Treatment of Experimental Periodontitis in Rats

Periodontitis (PD) is a severe inflammatory gum pathology that damages the periodontal soft tissue and bone. It is highly prevalent in the US, affecting more than 47% of adults. Besides routine scaling and root planing, there are few effective treatments for PD. Developed as an effective treatment for hyperlipidemia, simvastatin (SIM) is also known for its well-established anti-inflammatory and osteogenic properties, suggesting its potential utility in treating PD. Its clinical translation, however, has been impeded by its poor water-solubility, lack of osteotropicity, and side effects (e.g., hepatoxicity) associated with systemic exposure. To address these challenges, an N-(2-hydroxypropyl) methacrylamide (HPMA) copolymer-based thermoresponsive polymeric prodrug of SIM (ProGel-SIM) was developed as a local therapy for PD. Its aqueous solution is free-flowing at 4 °C and transitions into a hydrogel at ∼30 °C, allowing for easy local application and retention. After a thorough characterization of its physicochemical properties, ProGel-SIM was administered weekly into the periodontal pocket of an experimental rat model of PD. At 3 weeks post initiation of the treatment, the animals were euthanized with palate isolated for μ-CT and histological analyses. When compared to dose equivalent simvastatin acid (SMA, active form of SIM) treatment, the rats in the ProGel-SIM treated group showed significantly higher periodontal bone volume (0.34 mm3 vs 0.20 mm3, P = 0.0161) and less neutrophil (PMN) infiltration (P < 0.0001) and IL-1β secretion (P = 0.0036). No measurable side effect was observed. Collectively, these results suggest that ProGel-SIM may be developed as a promising drug candidate for the effective clinical treatment of PD.

Molecular Complex of HSIM-loaded Polymeric Nanoparticles: Potential Carriers in Osteoporosis

BACKGROUND

Statins, especially simvastatin promote bone formation by stimulating the activity of osteoblasts and suppressing osteoclast activity via the BMP-Smad signaling pathway. Statins present the liver first-pass metabolism. This study attempts to fabricate and evaluate simvastatin functionalized hydroxyapatite encapsulated in poly(lactic-co-glycolic) acid (PLGA) nanoparticles (HSIM-PLGA NPs) administered subcutaneously with sustained release properties for effective management of osteoporosis.

METHODS

Simvastatin functionalized hydroxyapatite (HSIM) was prepared by stirring and validated by docking studies, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD). Further, HSIM-loaded PLGA nanoparticles (HSIM-PLGA NPs) were developed via the solvent emulsification method. The nanoparticles were evaluated for zeta potential, particle size, entrapment efficiency, stability studies, and in vitro drug release studies. in vitro binding affinity of nanoparticles for hydroxyapatite was also measured. Bone morphology and its effect on bone mineral density were examined by using a glucocorticoid-induced osteoporosis rat model.

RESULTS

The optimized nanoparticles were found to be amorphous and showed no drug-polymer interaction. The particle size of formulated nanoparticles varied from 196.8 ± 2.27nm to 524.8 ± 5.49 nm and the entrapment efficiency of nanoparticles varied from 41.9 ± 3.44% to 70.8 ± 4.46%, respectively. The nanoparticles showed sustained release behaviour (75% in 24 hr) of the drug followed by non-fickian drug release. The nanoparticles exhibited high binding affinity to bone cell receptors, increasing bone mineral density. A significant difference in calcium and phosphorous levels was observed in disease and treatment rats. Porous bone and significant improvement in porosity were observed in osteoporotic rats and treated rats, respectively (P < 0.05).

CONCLUSION

Bone-targeting nanoparticles incorporating functionalized simvastatin can target bone. Thus, in order to distribute simvastatin subcutaneously for the treatment of osteoporosis, the developed nanoparticles may act as a promising approach.

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.

Electrochemical Oxidation of Different Therapeutic Classes of Pharmaceuticals Using Graphite-PVC Composite Electrode

This study reports electrochemical treatment of different therapeutic classes of pharmaceuticals (caffeine, prazosin, enalapril, carbamazepine, nifedipine, levonorgestrel, and simvastatin) in a mixture. The electrochemical process was investigated using graphite-PVC anode at different applied voltages (3, 5, and 12 V), initial concentrations of studied pharmaceuticals in aqueous solution (5 and 10 mg/L), and concentrations of sodium chloride (1 and 2 g/L). The % removal of pharmaceuticals increased with the applied voltage, and was found higher than 98% after 50 min of electrolysis at 5 V. Energy consumption ranged between 0.760 and 3.300 Wh/mg using 12 V being the highest value compared to 3 and 5 V. The formation of chlorinated by-products from four selected pharmaceuticals, simvastatin (C11H13Cl3O5, and C10H12Cl4O3), prazosin (C13H12Cl3N5O3 and C10H11Cl4N2O2), carbamazepine and caffeine (C15H11N2O2Cl and C8H9N4O2Cl) was identified and elucidated using liquid chromatography-time of flight mass spectrometry (LC-TOF/MS).

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 β-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 β-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.

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.

Solubilization and thermodynamic properties of simvastatin in various micellar solutions of different non-ionic surfactants: Computational modeling and solubilization capacity

The aim of this work was to solubilize simvastatin (SIM) using different micellar solutions of various non-ionic surfactants such as Tween-80 (T80), Tween-20 (T20), Myrj-52 (M52), Myrj-59 (M59), Brij-35 (B35) and Brij-58 (B58). The solubility of SIM in water (H₂O) and different micellar concentrations of T80, T20, M52, M59, B35 and B58 was determined at temperatures T = 300.2 K to 320.2 K under atmospheric pressure p = 0.1 MPa using saturation shake flask method. The experimental solubility data of SIM was regressed using van’t Hoff and Apelblat models. The solubility of SIM (mole fraction) was recorded highest in M59 (1.54 x 10⁻²) followed by M52 (6.56 x 10⁻³), B58 (5.52 x 10⁻³), B35 (3.97 x 10⁻³), T80 (1.68 x 10⁻³), T20 (1.16 x 10⁻³) [the concentration of surfactants was 20 mM in H₂O in all cases] and H₂O (1.94 x 10⁻⁶) at T = 320.2 K. The same results were also recorded at each temperature and each micellar concentration of T80, T20, M52, M59, B35 and B58. “Apparent thermodynamic analysis” showed endothermic and entropy-driven dissolution/solubilization of SIM in H₂O and various micellar solutions of T80, T20, M52, M59, B35 and B58.

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

Advanced therapeutic inhalation aerosols of a Nrf2 activator and RhoA/Rho kinase (ROCK) inhibitor for targeted pulmonary drug delivery in pulmonary hypertension: design, characterization, aerosolization, in vitro 2D/3D human lung cell cultures, and in vivo efficacy

Inhalable nanostructured microparticles of simvastatin, a Nrf2 activator and RhoA/Rho kinase (ROCK) inhibitor, were rationally designed for targeted pulmonary delivery as dry powder inhalers (DPIs) for the treatment of pulmonary hypertension (PH). Advanced particle engineering design technology was employed to develop inhalable dry powders using different dilute feed concentrations and spray drying pump rates. Several analytical techniques were used comprehensively to characterize the physicochemical properties of the resulting powders. Scanning electron microscopy (SEM) was used to visualize particle morphology (shape), surface structure, size, and size distribution. Karl Fischer titration (KFT) was employed to quantify the residual water content in the powders. X-ray powder diffraction (XRPD) was used to determine crystallinity. Hot-stage microscopy (HSM) under cross-polarizing lens was used to observe the presence or absence of birefringence characteristic of crystallinity. Differential scanning calorimetry (DSC) was employed to quantify thermotropic phase behavior. Attenuated total reflectance (ATR)-Fourier-transform infrared (FTIR) spectroscopy and Raman spectroscopy were used to determine the molecular fingerprint of simvastatin powders before and after particle engineering design. In vitro aerosol dispersion performance was performed with three different Food and Drug Administration (FDA)-approved human DPI devices. Cell viability and transepithelial electrical resistance (TEER) were demonstrated using different in vitro human pulmonary cell two and three-dimensional models at the air-liquid interface, and in vivo safety in healthy rats by inhalation. Efficacy was demonstrated in the in vivo lamb model of PH. Four different inhalable powders of simvastatin were successfully produced. They possessed nanostructured surfaces and were in the inhalable size range. Simvastatin retained its crystallinity following particle engineering design. The more dilute feed concentration spray dried at the lower pump rate produced the smallest particles. All powders successfully aerosolized with all three DPI human devices. Inhaled simvastatin as an aerosol restored the endothelial function in the shunt lamb model of PH, as demonstrated by the reduction of pulmonary vascular resistance (PVR) in response to the endothelium-dependent vasodilator acetylcholine.The reviews of this paper are available via the supplemental material section.

A promising nanomatrix system of simvastatin for oral delivery: Evaluation in vitro and in vivo

Because of the low solubility, the oral bioavailability of simvastatin (SV) was poor, which restricted the application in clinic. In order to increase the dissolution and the oral absorption of simvastatin, we prepared a novel solid nanomatrix of SV with pharmaceutical acceptable nano-sized silica and Eudragit®. The nanomatrix was prepared using solvent evaporate method and the formulation was optimized. The X-ray diffraction (XRD) and differential scanning calorimetry (DSC) were used to analyze the physicochemical characterization of the SV nanomatrix. The results indicated that the SV existed in the nanomatrix was in a state of molecule or amorphous form. The optimal formulation, consisted of SV, Eudragit® L100-55 and Sylysia 350 (1:5:5, w/w/w), significantly enhanced the dissolution of SV compared with Zocor. And the relative bioavailability was 272% to Zocor. The oral absorption of simvastatin was enhanced markedly. The SV nanomatrix after storage for 1 year displayed similar performance in vitro and in vivo with the freshly prepared nanomatrix. The stability of SV nanomatrix achieved the desired objectives. In conclusion, the nanomatrix system described here had superior performance in vitro and in vivo and was expected to have a promising future as an alternative oral drug delivery system for SV.

Modified electrospun chitosan membranes for controlled release of simvastatin

Chitosan nanofibrous membranes have immense potential in tissue engineering and drug delivery applications because of their increased surface area, high degree of biocompatibility, and their ability to mimic the extracellular matrix. However, their use is often limited due to their extreme hydrophilic nature causing them to lose their nanofibrous structure in vivo. In the present study, chitosan membranes were modified either by acylation reactions using fatty acids of different chain lengths or tert-butyloxycarbonyl (tBOC) protecting groups to increase the hydrophobicity of the membranes and protect the nanofibrous structure. The modified membranes were characterized using scanning electron microscopy, attenuated total reflectance Fourier transform infrared spectroscopy, water contact angle and elemental analysis to confirm the addition of the modification groups. These membranes were then evaluated to control the release of a hydrophobic osteogenic drug-simvastatin (SMV). The interaction between SMV and the polymer was determined using molecular modeling. Pure SMV and SMV loaded membranes were examined for their in vitro cytotoxicity and osteogenic potential using preosteoblast mouse bone marrow stromal cells. From results, it was evident that as the fatty acid chain length increased from two to six methylene groups, the hydrophobicity of the membranes increased (59.2 ± 8.2° to 94.3 ± 8.5° water contact angle). The amount of drug released from the membranes could be controlled by changing the amount of initial drug loaded and/or the type of modifications. After 4 weeks, for a 500 μg loading, the short chain fatty acid modified membranes released 17.8 ± 3.2% of the drug whereas a long chain fatty acid released only 4.8 ± 0.8%. Similarly, for a 50 μg loading, short chain modified membranes released more (73.3 ± 33.3%) of the loaded drug as compared to the long chain membranes (43.0 ± 3.5%). The long chain fatty acid membranes released SMV for extended time periods of up to 90 days. This data was further supported by molecular modeling, which revealed that SMV was more compatible with more hydrophobic membranes. Cell studies showed that pure SMV from 75 to 600 ng/ml range possessed osteogenic potential in a dose dependent manner and the amount of SMV released from the most hydrophobic FA treated membranes was not cytotoxic and supported osteogenic differentiation. Therefore, this study demonstrates our ability to control the release of a hydrophobic drug from modified chitosan membranes as per the clinical need.

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.

Improving the drug load and in vitro performance of supersaturated self-nanoemulsifying drug delivery systems (super-SNEDDS) using polymeric precipitation inhibitors

In this study, the influence of the polymeric precipitation inhibitor (PPI) PVP/VA 64 (polyvinylpyrrolidone-co-vinyl acetate) on the physical stability and in vitro performance of supersaturated self-nanoemulsifying drug delivery systems (super-SNEDDS) containing the model drug simvastatin (SIM) was investigated. A heating-cooling cycle was employed to dissolve (i) the drug in the SNEDDS preconcentrate, generating super-SNEDDS, or (ii) the drug and PPI generating PPI super-SNEDDS, both containing drug loads of 200% and 250% (with regard to the equilibrium solubility of SIM in the blank SNEDDS). PPI super-SNEDDS were prepared at PPI concentrations of 1%, 10% and 20% (w/w), respectively. The formulations were characterized using polarized light microscopy, dynamic light scattering, rheological profiling and dynamic in vitro lipolysis. The physical stability of PPI super-SNEDDS correlated with an increase in viscosity due to the additionally dissolved PVP/VA 64. PPI super-SNEDDS with drug loads of 200% and 250% containing 20% (w/w) PPI showed no drug recrystallization after more than 6 months of storage at room temperature, whereas PPI-free super-SNEDDS (250% drug load) recrystallized within two hours after equilibration to room temperature. All formulations formed nanosized droplets after emulsification in Milli-Q water. The droplet size was not affected by the PPI, but increased slightly with increasing drug load (z-average of 47.3 ± 0.4 nm for SNEDDS with 200% drug load and 55.6 ± 1.3 nm for SNEDDS with 250% drug load). PPI super-SNEDDS with a drug load of 200% containing 20% (w/w) PVP/VA 64 showed an improved performance during dynamic in vitro lipolysis, maintaining a 2.5-fold higher degree of supersaturation after 15 min of digestion compared to PPI-free super-SNEDDS of the same drug load. In conclusion, the study demonstrated the feasibility of stabilizing higher drug loads and improving the in vitro performance of super-SNEDDS by incorporating PVP/VA 64 into the preconcentrate.

Amino acids as stabilizers for spray-dried simvastatin powder for inhalation

BACKGROUND

The use of amino acids as excipients is a promising approach to improve the physical stability and powder dispersibility of spray-dried powders for inhalation.

OBJECTIVES

The aim of this study was to investigate the stabilizing effect of different amino acids on spray-dried amorphous powders for inhalation using simvastatin (SV) as a model compound.

METHODS

Two hydrophobic amino acids (leucine, LEU and tryptophan, TRP), and one hydrophilic amino acid (lysine, LYS) were spray dried from 1% (w/v) solutions with SV at a molar ratio of 1:1 into dry powders for inhalation. Scanning electron microscopy (SEM), X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC) and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) were used to characterize the morphology, solid form and potential intermolecular interactions of the spray-dried powders. X-ray photoelectron spectroscopy (XPS) was used to analyse the chemical composition of the surface of the particles. The physical stability of the dry powders was examined upon storage in controlled conditions. A Next generation impactor (NGI) was applied to assess the in vitro aerosol performance of the powders.

RESULTS

XRPD and DSC results confirmed that the spray-dried SV-LEU was composed of crystalline LEU and amorphous SV, the spray-dried SV-LYS was co-amorphous, and the spray-dried SV-TRP was an amorphous system with two phases. XPS analyses revealed that the surface of the spray-dried SV-LEU particles were LEU rich, indicating surface-enrichment of LEU in these particles. In contrast, an almost even distribution of TRP and SV at the surface of spray-dried SV-TRP was observed. FTIR results indicated no intermolecular interaction between SV and the amino acids used in the present study. The three spray-dried samples were physically stable after eight months storage in a desiccator (12% RH, ca. 22 °C). Nevertheless, spray-dried SV-LEU exhibited the best storage stability as compared to the other two spray-dried samples when the samples were stored at 60% RH, 25 °C. Both, the spray-dried SV-LEU and SV-TRP exhibited higher fine particle fractions than the spray-dried SV-LYS.

CONCLUSION

Both the spray-dried SV-LEU and SV-TRP exhibited better aerosol performance and storage stability compared to the spray-dried SV-LYS. Compared to TRP, LEU exhibited better protection of spray-dried amorphous SV from re-crystallization, which could be attributed to the formation of a LEU crystalline shell covering SV upon the spray drying process.

Hybrid Nanostructured Films for Topical Administration of Simvastatin as Coadjuvant Treatment of Melanoma

This work aims at (1) assessing the potential of repurposing simvastatin (SV) to support the most common therapies against melanoma and (2) developing an innovative topical adhesive film, composed by chitosan-coated nanostructured lipid carriers (Ch-NLC) used as drug vehicle. A factorial design approach was employed as the basis for the formulation development. Optimized Ch-NLC displayed a particle size of 108 ± 1 nm, a polydispersity index of 0.226, a zeta potential of 17.0 ± 0.6 mV, as well as an entrapment efficiency of 99.86 ± 0.08%, and SV loading of 14.99 ± 0.01%. The performance of SV-Ch-NLC films was assessed in terms of release, permeation, and adhesion, as critical quality attributes. Cutaneous tolerability and in vitro cytotoxicity studies were performed to warrant film safety and drug effectiveness, respectively. The topical films provided a sustained release kinetic profile of SV and were classified as nonirritant systems. The encapsulation of SV increased cytotoxicity in melanoma cells. The key role of squalene as nanostructuring agent of the lipid nanoparticle matrix and as permeation enhancer was highlighted, suggesting its key action for potentiating skin permeation and uptake into melanoma cells. Topical SV-Ch-NLC films are thus able to provide an in situ extended drug delivery and useful as coadjuvant treatment of melanoma skin lesions.

Simvastatin Nanoparticles Reduce Inflammation in LPS-Stimulated Alveolar Macrophages

Simvastatin (SV) is widely used as a lipid-lowering medication that has also been found to have beneficial immunomodulatory effects for treatment of chronic lung diseases. Although its anti-inflammatory activity has been investigated, its underlying mechanisms have not yet been clearly elucidated. In this study, the anti-inflammatory and antioxidant effects and mechanism of simvastatin nanoparticles (SV-NPs) on lipopolysaccharide-stimulated alveolar macrophages (AMs) NR8383 cells were investigated. Quantitative cellular uptake of SV-NPs, the production of inflammatory mediators (interleukin-6, tumor necrosis factor, and monocyte chemoattractant protein-1), and oxidative stress (nitric oxide) were tested. Furthermore, the involvement of the nuclear factor κB (NF-κB) signaling pathway in activation of inflammation in AMs and the efficacy of SV were visualized using immunofluorescence. Results indicated that SV-NPs exhibit a potent inhibitory effect on nitric oxide production and secretion of inflammatory cytokine in inflamed AM, without affecting cell viability. The enhanced anti-inflammatory activity of SV-NPs is likely due to SV-improved chemical-physical stability and higher cellular uptake into AM. The study also indicates that SV targets the inflammatory and oxidative response of AM, through inactivation of the NF-κB signaling pathway, supporting the pharmacological basis of SV for treatment of chronic inflammatory lung diseases.

Cheminformatics-driven discovery of polymeric micelle formulations for poorly soluble drugs

Many drug candidates fail therapeutic development because of poor aqueous solubility. We have conceived a computer-aided strategy to enable polymeric micelle-based delivery of poorly soluble drugs. We built models predicting both drug loading efficiency (LE) and loading capacity (LC) using novel descriptors of drug-polymer complexes. These models were employed for virtual screening of drug libraries, and eight drugs predicted to have either high LE and high LC or low LE and low LC were selected. Three putative positives, as well as three putative negative hits, were confirmed experimentally (implying 75% prediction accuracy). Fortuitously, simvastatin, a putative negative hit, was found to have the desired micelle solubility. Podophyllotoxin and simvastatin (LE of 95% and 87% and LC of 43% and 41%, respectively) were among the top five polymeric micelle-soluble compounds ever studied experimentally. The success of the strategy described herein suggests its broad utility for designing drug delivery systems.

Electrophoretic Deposition of Bioadaptive Drug Delivery Coatings on Magnesium Alloy for Bone Repair

Biodegradable polymer coatings on magnesium alloys are attractive, as they can provide corrosion resistance as well as additional functions for biomedical applications, e.g., drug delivery. A gelatin nanospheres/chitosan (GNs/CTS) composite coating on WE43 substrate was fabricated by electrophoretic deposition with simvastatin (SIM) loaded into the GNs. Apart from a sustained drug release over 28 days, an anticorrosion behavior of the coated WE43 substrates was confirmed by electrochemical tests. Both the degradation and corrosion rates of the coated substrate were significantly minimized in contrast to bare WE43. The cytocompatibility of the coated samples was analyzed  both quantitatively and qualitatively. Additionally, the osteogenic differentiation of MC3T3-E1 cells on SIM-containing coatings was assessed by measuring the expression of osteogenic genes and related proteins, alkaline phosphatase (ALP) activity, and extracellular matrix mineralization, showing that the SIM-loaded composite coating could upregulate the expression of osteogenic genes and related proteins, promote ALP activity, and enhance extracellular matrix mineralization. In summary, the SIM-loaded GNs/CTS composite coatings were able to enhance the corrosion resistance of the WE43 substrate and promote osteogenic activity, thus demonstrating a promising coating system for modifying the surface of magnesium alloys targeted for orthopedic applications.

The Combined Use of Phenothiazines and Statins Strongly Affects Doxorubicin-Resistance, Apoptosis, and Cox-2 Activity in Colon Cancer Cells

Since none of the multidrug resistance (MDR) modulators tested so far found their way into clinic, a novel approach to overcome the MDR of cancer cells has been proposed. The combined use of two MDR modulators of dissimilar mechanisms of action was suggested to benefit from the synergy between them. The effect of three phenothiazine derivatives that were used as single agents and in combination with simvastatin on cell growth, apoptosis induction, activity, and expression of cyclooxygenase-2 (COX-2) in doxorubicin-resistant colon cancer cells (LoVo/Dx) was investigated. Treatment of LoVo/Dx cells by phenothiazine derivatives combined with simvastatin resulted in an increase of doxorubicin cytotoxicity and its intracellular accumulation as compared to the treatment with phenothiazine derivatives that were used as single agents. Similarly, LoVo/Dx cells treated with two-component mixture of modulators showed the reduced expression of ABCB1 (P-glycoprotein) transporter and COX-2 enzyme, both on mRNA and protein level. Reduced expression of anti-apoptotic Bcl-2 protein and increased expression of pro-apoptotic Bax were also detected. Additionally, COX-2 activity was diminished, and caspase-3 activity was increased to a higher extent by phenothiazine derivative:simvastatin mixtures than by phenothiazine derivatives themselves. Therefore, the introduction of simvastatin strengthened the anti-MDR, anti-inflammatory, and pro-apoptotic properties of phenothiazines in LoVo/Dx cells.