Nanodesigning of multifunctional quantum dots and nanoparticles for the treatment of fibrosarcoma.

An effective, dual drug(DD) loaded nanocarrier system (nano particle(NP), quantum dots(QDs)) having two active substances was aimed to develop for the treatment of fibrosarcoma. Zinc oxide(ZnO) QDs were produced using zinc acetate dehydrate as a precursor, were incorporated with chitosan(Ch), and finally decorated with PEG-linked folic acid and were found to be effective after imatinib mesylate(IM) and dexketoprofen trometamol(DT) were loaded. Characterisations, in vitro drug releases, cell toxicities, penetrations through cell lines and in-vivo animal tests of the prepared nanosystems were performed. The size of hybrid nanoparticles were 168.6 ± 48.8 nm, surface charge was -35.8 ± 0.26 mV. The encapsulation efficiency was 75% for IM and 99% for DT. DD-functionalised QDChNPs and lyophilised functionalised QDChNPs in capsules slowed down tumour growth by up to 76.5 and 88.7%. Our results demonstrate that developed hybrid nanoparticles are highly effective. This hybrid system gathers many of the advantages of nanotechnology into one form.

Development of effective AmB/AmB-αCD complex double loaded liposomes using a factorial design for systemic fungal infection treatment.

Amphotericin B (AmB) is a very potent antibiotic which still remains as the gold standard for the treatment of systemic fungal infections. AmB is a member of Biopharmaceutical Classification System Class IV, mainly characterized by its poor solubility and low permeability. In this study, AmB/AmB-α cyclodextrin complex double loaded liposomes (DLLs) were developed using the design of experiments (DoE®) approach to optimize/determine the effects of lipid composition and other parameters on final product properties such as encapsulation efficacy, particle size, polydispersity index, and zeta potential. Experimental design 24 was used for optimization of these properties in which four factors were studied in two levels. DLLs showed much higher physical stability than liposomes loaded only with free AmB by the means of particle size, zeta potential and encapsulation efficiency, in addition exhibited sustained release of AmB over 72 h (26.7%) with faster onset time. On the other hand, fourfold improved antimicrobial efficiency, minimum inhibitory concentration (0.125 µg/ml), and minimum fungicidal concentration (0.5 µg/ml) was determined by DLLs against C. albicans compared to Ambisome®. Dose dependent effects of the DLLs were investigated by cytotoxicity studies on Vero and L-929 cells. No significant cytotoxicity observed for AmB/AmB-αCD complex DLLs and Ambisome at tested concentrations while free AmB caused severe cytotoxicity. Lastly the developed DLLs did not cause an increase in NGAL (an early biomarker for acute kidney toxicity) levels for both Vero and HK-2 cell lines compared to free AmB.

Efficacy of targeted liposomes and nanocochleates containing imatinib plus dexketoprofen against fibrosarcoma.

The main challenges in treating cancer using chemotherapeutics are insufficient dose at the target site and the development of drug resistance, while higher doses can induce side effects by damaging nontarget tissues. Combinatorial drug therapy may overcome these limitations by permitting lower doses and more specific targeting, thereby mitigating drug resistance and nontarget side effects. Recent reports indicate that nonsteroidal anti-inflammatory drugs (NSAIDs) have anticancer potential and can be used together with conventional chemotherapeutics to improve efficacy and safety. In the present study, imatinib mesylate and dexketoprofen trometamol were selected as model drugs to develop targeted surface-modified liposome and nanocochleate formulations for fibrosarcoma treatment. The physicochemical properties and in vitro efficacy of various formulations were evaluated by measurement of particle size distribution, polydispersity index, zeta potential, encapsulation efficiency, diffusion through Caco-2 cells, and toxicity in culture. Selected formulations were then evaluated in fibrosarcoma-bearing model mice by histopathological observations and tyrosine kinase receptor inhibition assays. The most effective formulation on the fibrosarcoma model was a PEGylated nanocochleate formulation. These findings provide a foundation for developing more effective formulations and chemotherapeutic strategies for the treatment of fibrosarcoma and other types of cancer.

Novel Approach to the Treatment of Diabetes: Embryonic Stem Cell and Insulin-Loaded Liposomes and Nanocochleates.

This study aims to investigate and compare the effects of insulin and embryonic stem-cell (ESC) loaded liposomes (LPs) and nanocochleate formulations and their PEGylated forms on the glucose levels. All formulations were characterized considering particle size, zeta potential, polydispersity index and encapsulation efficiencies. In-vitro insulin that releases from the formulations was determined using Franz-type diffusion cells. A cytotoxicity test revealed that none of the formulations was toxic to cells in any concentrations. The effects of the formulations on diabetic cells induced with glucose and streptozotocin (STZ) were then investigated in cell culture studies. Although glucose levels were decreased by the formulations after incubation, the liposomal formulations were found to be better. In experiments that were conducted on mice, it was observed again that blood glucose levels decreased successfully when diabetic pancreatic beta TC cells were incubated with the formulations, and all formulations were found to be effective in decreasing blood glucose levels in diabetic mice. Although ESC-loaded LPs were found to be the most effective formulation, LPs and nanocochleate formulations may also be used for the repair of pancreatic cells. This proposed ESC treatment is considered to be an attractive approach and a potential source for cell replacement therapy in the treatment of diabetes.

[Investigation of cytokine and midkine responses of human THP-1 leukemia cells induced by phorbol-12-Myristate-13-Acetate (PMA) at different concentrations and times]. / Degisik konsantrasyonlarda ve sürelerde Phorbol-12-Myristate-13-Acetate ile uyarilan insan THP-1 lösemi hücrelerinin sitokin ve midkin yanitlarinin arastirilmasi.

Macrophages are accepted as cells that initially contact with the pathogens and initiate the innate immune response. They play effective roles in innate immune and inflammatory responses by intercellular relations and inflammatory mediator secretion. Human THP-1 leukemia cells are frequently used for the in vitro determination of the signal pathways, and the functions of macrophages. Phorbol-12-Myristate-13-Acetate (PMA) is commonly used to induce macrophage differentiation of monocytic cell lines but the extent of differentiation in comparison to primary tissue macrophages is unclear. Midkine acts as a cytokine and growth factor which organizes proliferation, differentiation, survival, adhesion and migration of immune cells. The aim of this study was to observe the differences in the secretion of midkine, TNF-α, IL-10 and IFN-γ of macrophages differentiated from monocytes when stimulated with different doses of PMA for different durations. For this purpose, THP-1 monocytic cells were proliferated by PMA at 24, 48 and 72 hours by using the concentrations of 10 ng/ml, 20 ng/ml, 40 ng/ml and 60 ng/ ml. Midkine, TNF-α, IL-10 and IFN-γ cytokine levels were determined by ELISA in the supernatants of the cells collected at the end of incubation times. PMA stimuli initiated changes that were indicative of differentiation in the cell morphology. Differentiation of cells by PMA induced midkine, TNF-α, IL-10 and IFN-γ secretions in monocytic cells even at the lowest dosage (10 ng/ml). PMA caused cytotoxicity in the cells when the dosages were increased (> 20 ng/ml). THP-1 cells have a basal secretion of midkine and are increased by dosage dependent with PMA stimulation. Midkine secretion has shown changes dependent with dosage and time. A difference was also observed in the cytokine profile of PMA stimulated cells at different doses. The results indicated that the differentiation of THP-1 monocytes to macrophages requires optimization to ensure that this in vitro macrophage model more precisely reflects real in vivo physiologic conditions. As a conclusion the results have shown that a modified PMA differentiation protocol (20 ng/ml and 48 hours incubation) might enhance macrophage differentiation of THP-1 cells without induced cell death (viability 92.2%) and cytokine secretion and midkine responses were the important discriminators of the level of macrophage differentiation.

Development of Orally Applicable, Combinatorial Drug-Loaded Nanoparticles for the Treatment of Fibrosarcoma.

Nanoparticulate systems have been receiving a significant attention especially for the treatment of cancer but one of the main hurdles is to produce these developed and high-tech nanosystems in large quantities. Anticancer drug formulations are generally designed for parenteral administrations but oral administration is still the most convenient route. In this study, orally applicable nano-sized chitosan nanoparticles (NPs) were successfully prepared using Nano Spray Dryer. It is possible to produce these NPs in large quantities by simply increasing the processing time using the machine without changing any parameter. A chemotherapeutic agent (imatinib mesylate; IMA) and nonsteroidal anti-inflammatory drug (dexketoprofen trometamol) were loaded together in these NPs. NPs were also functionalized with polyethylene glycol and folic acid to obtain long circulating NPs and tumor targeting. The antitumoral activities of formulations showed that these developed NPs can enhance the effectiveness. Animal experiments were performed on fibrosarcoma-bearing mice model, and the treatment with 0.8 mg/µL/kg IMA-loaded chitosan NPs was found to be successful to slow down the growth of tumors. The tumor tissues were removed from the animals and enzymatic activities were evaluated. The inhibitory effect of tyrosine kinase was found to be enhanced from 36.4% to 68.4% when IMA was used in combination with dexketoprofen trometamol. Furthermore, all dried NPs were found to be stable for more than a year at 25°C. Presented results show that these developed combinatorial drug-loaded NPs can be used for the treatment of fibrosarcoma, and these data can provide an insight, new strategies for productions or alternatives in cancer treatment.

Co-delivery of pemetrexed and miR-21 antisense oligonucleotide by lipid-polymer hybrid nanoparticles and effects on glioblastoma cells.

Combination therapy using anticancer drugs and nucleic acid is a more promising strategy to overcome multidrug resistance in cancer and to enhance apoptosis. In this study, lipid-polymer hybrid nanoparticles (LPNs), which contain both pemetrexed and miR-21 antisense oligonucleotide (anti-miR-21), have been developed for treatment of glioblastoma, the most aggressive type of brain tumor. Prepared LPNs have been well characterized by particle size distribution and zeta potential measurements, determination of encapsulation efficiency, and in vitro release experiments. Morphology of LPNs was determined by transmission electron microscopy. LPNs had a hydrodynamic size below 100 nm and exhibited sustained release of pemetrexed up to 10 h. Encapsulation of pemetrexed in LPNs increased cellular uptake from 6% to 78%. Results of confocal microscopy analysis have shown that co-delivery of anti-miR-21 significantly improved accumulation of LPNs in the nucleus of U87MG cells. Nevertheless, more effective cytotoxicity results could not be obtained due to low concentration of anti-miR-21, loaded in LPNs. We expect that the effective drug delivery systems can be obtained with higher concentration of anti-miR-21 for the treatment of glioblastoma.

The Effectiveness of Raloxifene-Loaded Liposomes and Cochleates in Breast Cancer Therapy.

Liposome (spherical vesicles) and cochleate (multilayer crystalline, spiral structure) formulations containing raloxifene have been developed having dimethyl-ß-cyclodextrin (DM-ß-CD) or sodium taurocholate (NaTC). Raloxifene was approved initially for the treatment of osteoporosis but it is also effective on breast tissue and endometrial cells. Raloxifene inhibits matrix metalloproteinase-2 (MMP-2) enzyme, which is known to be responsible for tumor invasion and the initiation of angiogenesis during the tumor growth. Therefore, raloxifene was selected as a model drug. A series of raloxifene-loaded liposome and cochleate formulations were prepared. In vitro release studies and in vivo tests were performed. Breast cancer cell lines (MCF-7) were also used to find the most effective formulation. Highest antitumor activity was observed, and MMP-2 enzyme was also found to be inhibited with raloxifene-loaded cochleates containing DM-ß-CD. These developed formulations can be helpful for further treatment alternatives and new strategies for cancer therapy.

Synthesis, in-vitro cytotoxic activity and DNA interactions of new dicarboxylatoplatinum(II) complexes with 2-hydroxymethylbenzimidazole as carrier ligands.

OBJECTIVES: The aim of this study was to investigate the in-vitro cytotoxic activity of new platinum(II) complexes on the human HeLa (ER-), MCF-7 (ER+) and MDA-MB 231 (ER-) cell lines. Furthermore, we investigated plasmid DNA interactions and inhibition of BamHI and HindIII restriction enzyme activity of the complex 1-4,7. METHODS: Platinum(II) complexes were synthesised from precursor complexes of [PtL2 Cl2 ] and [PtL2 I2 ]. Their cytotoxic activity was tested by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Their plasmid DNA interactions and restriction enzyme activities were also investigated using the agarose gel electrophoresis method. KEY FINDINGS: The growth inhibitory effect results showed that the cytotoxicity of complex 2 was found to be the most active complex among the synthesised complexes. CONCLUSIONS: The MTT results showed that complex 2 was found to be cytotoxic equal to cisplatin and higher than carboplatin against the MCF-7 and MDA-MB-231 cell lines. Furthermore, the estrogen or progesterone co-treatment slightly increased the cytotoxicity of complex 2, the cisplatin and carboplatin compared with the complex 2 tested alone in 50 µm concentration. According to plasmid DNA interaction and the restriction studies, complexes 1-4,7 modified the tertiary structure of pBR322 plasmid DNA, and complexes 2-4 prevented enzyme digestion at high concentrations.

Nanoparticle and liposome formulations of doxycycline: transport properties through Caco-2 cell line and effects on matrix metalloproteinase secretion.

Nanoparticle and liposome formulations containing doxycycline or doxycycline and sodium taurocholate (NaTC) were developed in this study. The anticancer effects of doxycycline and penetration properties from those formulations through Caco-2 cell monolayers were investigated. Matrix metalloproteinases (MMPs) have been reported to play a role in the negative prognosis of many malignant tumors including glioblastoma multiforme (GBM). This study is presented to demonstrate that these developed nanoparticle and liposome formulations of doxycycline are capable of inhibiting MMP-2 release from cultured Caco-2 cells. In this study, Caco-2 cells were used as model cell cultures. A MTT test was performed to determine the effect of doxycycline on the viability of Caco-2 cells. Doxycycline nanoparticles were prepared using emulsion polymerization and doxycycline liposomes were prepared using the dry film hydration method. Transport studies of doxycycline through Caco-2 cells were investigated. MMP-2 was found to be inhibited more with doxycycline if NaTC is present in the formulation. NaTC was also found to be useful to increase penetration due to the inhibition of efflux by interacting with p-glycoproteins, in addition to the penetration enhancing effect as a result of opening tight junctions. These developed formulations were proposed to use for the treatment of tumors and GBM.

Cytotoxicity and DNA interactions of some platinum(II) complexes with substituted benzimidazole ligands.

In the present study, four Pt(II) complexes with 2-ethyl (1)/or benzyl (2)/or p-chlorobenzyl (3)/or 2-phenoxymethyl (4) benzimidazole carrier ligands were evaluated for their in vitro cytotoxic activities against the human HeLa cervix, oestrogen receptor-positive MCF-7 breast, and oestrogen receptor-negative MDA-MB 231 breast cancer cell lines. The plasmid DNA interactions and inhibition of the BamHI restriction enzyme activities of the complexes were also studied. Complex 3 was found to be more active than carboplatin for all examined cell lines and comparable with cisplatin, except for the HeLa cell line.

Effect of reduced exposure times on the cytotoxicity of resin luting cements cured by high-power led.

OBJECTIVE: Applications of resin luting agents and high-power light-emitting diodes (LED) light-curing units (LCUs) have increased considerably over the last few years. However, it is not clear whether the effect of reduced exposure time on cytotoxicity of such products have adequate biocompatibility to meet clinical success. This study aimed at assessing the effect of reduced curing time of five resin luting cements (RLCs) polymerized by high-power LED curing unit on the viability of a cell of L-929 fibroblast cells. MATERIAL AND METHODS: Disc-shaped samples were prepared in polytetrafluoroethylene moulds with cylindrical cavities. The samples were irradiated from the top through the ceramic discs and acetate strips using LED LCU for 20 s (50% of the manufacturer's recommended exposure time) and 40 s (100% exposure time). After curing, the samples were transferred into a culture medium for 24 h. The eluates were obtained and pipetted onto L-929 fibroblast cultures (3x10(4) per well) and incubated for evaluating after 24 h. Measurements were performed by dimethylthiazol diphenyltetrazolium assay. Statistical significance was determined by two-way ANOVA and two independent samples were compared by t-test. RESULTS: Results showed that eluates of most of the materials polymerized for 20 s (except Rely X Unicem and Illusion) reduced to a higher extent cell viability compared to samples of the same materials polymerized for 40 s. Illusion exhibited the least cytotoxicity for 20 s exposure time compared to the control (culture without samples) followed by Rely X Unicem and Rely X ARC (90.81%, 88.90%, and 83.11%, respectively). For Rely X ARC, Duolink and Lute-It 40 s exposure time was better (t=-1.262 p=0,276; t=-9.399 p=0.001; and t=-20.418 p<0.001, respectively). CONCLUSION: The results of this study suggest that reduction of curing time significantly enhances the cytotoxicity of the studied resin cement materials, therefore compromising their clinical performance.

Effect of reduced exposure times on the cytotoxicity of resin luting cements cured by high-power led

OBJECTIVE: Applications of resin luting agents and high-power light-emitting diodes (LED) light-curing units (LCUs) have increased considerably over the last few years. However, it is not clear whether the effect of reduced exposure time on cytotoxicity of such products have adequate biocompatibility to meet clinical success. This study aimed at assessing the effect of reduced curing time of five resin luting cements (RLCs) polymerized by high-power LED curing unit on the viability of a cell of L-929 fibroblast cells. MATERIAL AND METHODS: Disc-shaped samples were prepared in polytetrafluoroethylene moulds with cylindrical cavities. The samples were irradiated from the top through the ceramic discs and acetate strips using LED LCU for 20 s (50 percent of the manufacturer's recommended exposure time) and 40 s (100 percent exposure time). After curing, the samples were transferred into a culture medium for 24 h. The eluates were obtained and pipetted onto L-929 fibroblast cultures (3x10(4) per well) and incubated for evaluating after 24 h. Measurements were performed by dimethylthiazol diphenyltetrazolium assay. Statistical significance was determined by two-way ANOVA and two independent samples were compared by t-test. RESULTS: Results showed that eluates of most of the materials polymerized for 20 s (except Rely X Unicem and Illusion) reduced to a higher extent cell viability compared to samples of the same materials polymerized for 40 s. Illusion exhibited the least cytotoxicity for 20 s exposure time compared to the control (culture without samples) followed by Rely X Unicem and Rely X ARC (90.81 percent, 88.90 percent, and 83.11 percent, respectively). For Rely X ARC, Duolink and Lute-It 40 s exposure time was better (t=-1.262 p=0,276; t=-9.399 p=0.001; and t=-20.418 p<0.001, respectively). CONCLUSION: The results of this study suggest that reduction of curing time significantly enhances the cytotoxicity of the studied resin cement materials, therefore compromising their clinical performance.

New perspective for the treatment of Alzheimer diseases: liposomal rivastigmine formulations.

The aim of this study was to determine the transportations of rivastigmine containing from various liposome formulations through Madin Darby Canine Kidney (MDCK) cells monolayer and to compare the in vitro test results with in vivo. There is no other liposome formulation of rivastigmine and the transportations of rivastigmine through MDCK cell monolayers or related study available in the literature. Cytotoxicity (MTT) test was used to determine cell viabilities. The effect of sodium-taurocholate or dimethyl-beta-cyclodextrine as penetration enhancer was also investigated. Characterization and stability studies for liposome formulations were performed. Permeation experiments of rivastigmine were performed through MDCK cells and dialysis membrane. The kinetic of release from liposomes was also investigated. The highest apparent permeability coefficient (log. values) was obtained with sodium-taurocholate liposomes for -1.15 ± 0.16 for MDCK cell. Rivastigmine liposomes and solutions were also administered to mice orally and intraperitonally. Acetylcholinesterase (AChE) activity was determined by Ellman method. AChE% inhibition values were calculated for both blood and brain after administration of rivastigmine solution and liposomes. The highest AChE inhibition was observed for rivastigmine-sodium-taurocholate liposomes. Histological observations of the mice' brains were performed under transmission electron microscope (TEM). The histological results were also indicated and supported all these findings.

Carbon nanotubes to deliver drug molecules.

Nanotechnology is rapidly developing field in especially engineering and medical sciences. Carbon nanotubes are one of the most studied nanomaterials in material sciences and physics. Although there are limitted number of studies have been performed with carbon nanotubes in medical sciences and pharmacy, to use carbon nanotubes as drug delivery material is still at beginning and at developing stage. Carbon nanotubes are adsorptive materials and they can actively adsorb drug molecules on the surface. In this study the adsorption properties of carbon nanotubes were investigated for ibuprofen, naproxen, oxaliplatin and paclitaxel. Desorption properties and the posibility of using them as drug delivery systems for mentioned drugs were investigated and determined. Multiwalled carbon nanotubes were also PEGylated and PEGylation was found to be successful and effective. Particle sizes and zeta potentials of carbon nanotubes were not altered after PEGylation.

Synthesis, cytotoxicity, and DNA interactions of new cisplatin analogues containing substituted benzimidazole ligands.

Six new platinum(II) complexes with 1-H or methyl-2-chloromethyl or acetoxymethyl or 2'-hydroxyethylbenzimidazole carrier ligands were synthesized and evaluated for their reactivity against model nucleophile I(-), cellular uptake, and in vitro antiproliferative activities against the human MCF-7 breast and HeLa cervix cancer cell lines. The effect of the compounds on pBR322 plasmid DNA was studied by gel electrophoretic mobility measurements. Flow cytometric analysis was also carried out to study the effect of representative compounds 1 and 2, bearing 2-chloromethyl or -acetoxymethylbenzimidazole carrier ligands, on the cell cycle distribution of MCF-7 and HeLa cells, respectively. In general, it was found that Pt(II) complexes were less cytotoxic than cisplatin and were comparable to carboplatin. The results of the plasmid DNA interaction and the restriction studies suggest that changing the chemical structure of the benzimidazole ligands may modulate DNA binding mode and the sequence selectivity. Compounds 1 and 2 had no significant effect on the cell cycle profile of the cells used. However, compound 2 induced a significant increase in the SubG1 cell population at a concentration of 20 microM.

In vitro evaluation of cytotoxicity of soft lining materials on L929 cells by MTT assay.

The aim of this in vitro study was to evaluate five commonly used soft lining materials, Viscogel (VG), Ufi Gel P (UGP), Softliner (S), Coe-Soft (CS), and Molloplast-B (MB) in terms of cytotoxicity by MTT assay, using L929 mouse fibroblasts. Sixteen disk-shaped specimens from each material were prepared (according to the manufacturer's instructions) in stainless steel mold (10 mm diameter and 1.5 mm thick). The specimens were incubated for 24, 48, 72, and 96 h in Dulbecco's Modified Eagle Medium Ham's F12 (DMEM/F12) and following each incubation interval, cytotoxicity of the extracts to cultured mouse fibroblasts (L929) were measured by MTT assay. Data were statistically analyzed by two-way analysis of variance (ANOVA), and Duncan's test, at a significance level of p < 0.05. Group CS revealed significantly high cytotoxic effect at all incubation periods (p < 0.05). Although no cytotoxic effect for Group S was found at 24, 48, 72 h periods, it has been raised at 96-h incubation period (p > 0.05). Group VG, UGP, S (except at 96 h period), and Group MB demonstrated high cell survival rates at incubation periods.

In vitro cytotoxicity of maxillofacial silicone elastomers: effect of accelerated aging.

The purpose of this in vitro study was to evaluate the cytotoxicity of three maxillofacial silicone elastomers at 24, 48, and 72 h on L-929 cells and to determine the effect of accelerated aging on the cytotoxicity of these silicone elastomers. Disc-shaped test samples of maxillofacial silicone elastomers (Cosmesil, Episil, Multisil) were fabricated according to manufacturers' instructions under aseptic conditions. Samples were then divided into three groups: (1) not aged; (2) aged for 150 h with an accelerated weathering tester; and (3) aged for 300 h. Then the samples were placed in Dulbecco's Modified Eagle Medium/Ham's F12 (DMEM/F12) for 24, 48, and 72 h. After the incubation periods, cytotoxicity of the extracts to cultured fibroblasts (L-929) was measured by MTT assay. The degree of cytotoxicity of each sample was determined according to the reference value represented by the cells with a control (culture without sample). Statistical significance was determined by repeated measurement ANOVA (p < 0.01) followed by Duncan's test (p < 0.05). All test materials in each group demonstrated high survival rates in MTT assay (Episil; 93.84%, Multisil; 88.30%, Cosmesil; 87.50%, respectively); however, in all groups, Episil material demonstrated significantly higher cell survival rate after each of the experimental incubation periods (p < 0.05). Accelerated aging for 150 and 300 h had no significant effect on the biocompatibility of maxillofacial silicone elastomers tested (p > 0.05).