Preparation and Characterization of Magnetic Solid Lipid Nanoparticles as a Targeted Drug Delivery System for Doxorubicin.

Purpose: In the present study, we investigated the magnetic solid lipid nanoparticles (mSLNs) for targeted delivery of doxorubicin (DOX) into breast cancer cells. Methods: The synthesis of iron oxide nanoparticles was carried out by co-precipitation of a ferrous and ferric aqueous solution with the addition of a base; moreover, during precipitation process, the magnetite nanoparticles should be coated with stearic acid (SA) and tripalmitin (TPG). An emulsification dispersion-ultrasonic method was employed to prepare DOX loaded mSLNs. Fourier transforms infrared spectroscopy, vibrating sample magnetometer, and photon correlation spectroscopy (PCS) were used to characterize the subsequently prepared nanoparticles. In addition, the antitumor efficacy of particles was evaluated on MCF-7 cancer cell lines. Results: The findings showed that entrapment efficiency values for solid lipid and magnetic SLNs were 87±4.5% and 53.7±3.5%, respectively. PCS investigations showed that particle size increased with magnetic loading in the prepared NPs. In vitro drug release of DOX-loaded SLN and DOX-loaded mSLN in phosphate buffer saline (pH=7.4) showed that the amount of drug released approached 60% and 80%, respectively after 96 h of incubation. The electrostatic interactions between magnetite and drug had little effect on the release characteristics of the drug. The higher toxicity of DOX as nanoparticles compared to free drug was inferred from in vitro cytotoxicity. Conclusion: DOX encapsulated magnetic SLNs can act as a suitable and promising candidate for controlled and targeted therapy for cancer.

Using the aluminum decorated graphitic-C3N4 quantum dote (QD) as a sensor, sorbent, and photocatalyst for artificial photosynthesis; a DFT study.

In this project, we have investigated the possibility of mimicking the natural photosynthesis, as well as sensing and adsorption application of aluminum decorated graphitic C3N4 (Al-g-C3N4) QDs (toward some air pollutants containing CO, CO2, and SO2). The results of the potential energy surface (PES) studies show that in all three adsorption processes, the energy changes are negative (-10.70 kcal mol-1, -16.81 kcal mol-1, and -79.97 kcal mol-1 for CO, CO2, and SO2 gasses, respectively). Thus, all of the adsorption processes (mainly SO2) are spontaneous. Moreover, the frontier molecular orbital (FMO) investigations indicate that the Al-g-C3N4 QD could be used as a suitable semiconductor sensor for detection of CO, and CO2 (as carbon oxides) in one hand, and SO2 gaseous species on the other hand. Finally, the results reveal that those QDs could be applied for artificial photosynthesis (in presence of CO2; Δµh-e = 1.43 V), and for water splitting process for the H2 generation (Δµh-e = 1.23 V) as a clean fuel for near future.

Lysine Decorated Solid Lipid Nanoparticles of Epirubicin for Cancer Targeting and Therapy.

Purpose: Cancer is an example of the most important growing diseases in human society and scientists are trying to treat it without considerable side effects on patient's health. Solid lipids are colloidal nanoparticles that were used in drug delivery due to their several advantages. Methods: In this work, surface modified targeted solid lipid nanoparticles (SLNs) were fabricated by nano-homogenizer using tripalmitin glyceride and stearic acid as lipid constituents. The size of nanoparticles and morphological evaluations were surveyed using particle size analyzer, scanning electron microscopy; Fourier transforms infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC). Results: The particle size of 148.5 and appropriate polydispersity index were achieved for lipid nanoparticles with an entrapment efficiency of 86.1%. The FT-IR analysis confirmed the coupling of lysine to the free functional group of SLNs. DSC proved the conjugation of amino acid to the surface of carriers. The in vitro epirubicin (EPI) release test exhibited the further controlled release phenomenon for the lysine conjugated nanoparticles. The cytotoxicity assay showed lower IC50 of lysine conjugated SLNs of EPI on the investigated cell line. Conclusion: These studies showed that the fabricated targeted carrier has a very remarkable anticancer effect on breast cancer cell lines in comparison with pure drug.

The possibility of using C20 fullerene and graphene as semiconductor segments for detection, and destruction of cyanogen-chloride chemical agent.

Detection of hazardous chemical species by changing the electrical conductivity of a semiconductor matter is a proposed and applied way for decreasing their subsequent unpleasant effects. Recently, many examples of using inorganic or organic materials, polymeric, and also nano-sized species as sensors were reported in which, in some cases, those matters were strongly affective and suitable. In this project, we have made an assessment on whether the graphene segment or C20 fullerene, able to sense the existence of cyanogen chloride NCCl? In order to gain trustable results, the possible reaction pathways along with the adsorption kinetics were investigated. Moreover, the electronic density of states DOS showed that C20 fullerene senses the existence of cyanogen chloride agent with a clearer signal (ΔEg=0.0110eV) compared to the graphene segment (ΔEg=0.0001eV). Also the adsorption energy calculations showed that cyanogen chloride could be adsorbed by the fullerene in a multi-step process (Eads1=-0.852kcalmol-1; Eads2=-0.446kcalmol-1; Eads3=-2.330kcalmol-1).

Multivariate spectrochemical analysis of interactions of three common Isatin derivatives to calf thymus DNA in vitro.

Interactions of Isatin and its derivatives, Isatin-3-isonicotinylhydrazone (IINH) and Isatin-ß-thiosemicarbazone (IBT), with calf thymus DNA (ctDNA) have been investigated to delineate pharmaceutical-physicochemical properties using UV-Vis/fluorescence/circular dichroism (CD) spectroscopy, viscosity measurements, and multivariate chemometrics. IINH and IBT molecules intercalate between base pairs of DNA, hypochromism in UV absorptions, increase in the CD positive band, sharp increase in specific viscosity, and the displacement of the methylene blue and Neutral Red dye in complexes with ctDNA, by the IINH and IBT molecules, respectively. The observed intrinsic binding constants (Kb[IBT-ctDNA] = 1.03 × 105 and Kb[IINH-ctDNA] = 1.09 × 105 L mol-1) were roughly comparable to other intercalators. In contrast, Isatin binds with ctDNA via groove mode (Kb[Isatin-ctDNA] = 7.32 × 104 L mol-1) without any significant enhancement in ctDNA viscosity. The fluorescence quenching of Isatin by ctDNA was observed as static. CD spectra indicated that Isatin effectively absorbs into grooves of ctDNA, leading to transition from B to C form. Thermodynamic parameters like enthalpy changes (∆H < 0) and entropy changes (∆S > 0) were calculated according to Van't Hoff's equation, indicating the spontaneous interactions. The common soft/hard chemometric methods were used not only to resolve pure concentration and spectral profiles of components using the acquired spectra but also to calculate Stern-Volmer quenching constants, binding stoichiometry, apparent binding constants (Ka), binding constants (Kb), and thermodynamic parameters. The Kb values for Isatin, IINH, and IBT were calculated as 9.18 × 103, 1.53 × 105, and 2.45 × 104 L mol-1, respectively. The results obtained from experimental-spectroscopic analyses showed acceptable agreement with chemometric outlines.

Study on the Interaction between Isatin-ß-Thiosemicarbazone and Calf Thymus DNA by Spectroscopic Techniques.

The interaction between isatin-ß-thiosemicarbazone (IBT) and calf thymus DNA (CT-DNA) was investigated in physiological buffer (pH 7.4) using Neutral Red (NR) dye as a spectral probe by UV-Vis absorption and fluorescence spectroscopy, as well as viscosity measurements. The IBT is stabilized by intercalation in the DNA (K [IBT -DNA] = 1.03×10(5) M(-1)), and displaces the NR dye from the NR-DNA complex. The binding constants Kf and number of binding sites (n≈1) of IBT with DNA were obtained by fluorescence quenching method at different temperatures. Furthermore, the enthalpy and entropy of the reaction between IBT and CT-DNA showed that the reaction is enthalpy-favored and entropy-disfavored. The changes in the base stacking of CT-DNA upon the binding of IBT are reflected in the circular dichroic (CD) spectral studies. The viscosity increase of CT-DNA solution is another evidence to indicate that, IBT is able to be intercalated in the DNA base pairs.

Biochemical and pharmacological characterization of isatin and its derivatives: from structure to activity.

Isatin, 1H-indole-2,3-dione, is a heterocyclic compound of significant importance in medicinal chemistry. It is a synthetically versatile molecule, a precursor for a large number of pharmacologically active compounds. Isatin and its derivatives have aroused great attention in recent years due to their wide variety of biological activities, relevant to application as insecticides and fungicides and in a broad range of drug therapies, including anticancer drugs, antibiotics and antidepressants. The purpose of this review is to provide an overview of the pharmacological activities of isatin and its synthetic and natural derivatives. Molecular modifications to tailor the properties of isatin and its derivatives are also discussed.

Molecular aspects on the interaction of isatin-3-isonicotinylhydrazone to deoxyribonucleic acid: model for intercalative drug-DNA binding.

Isatin-3-isonicotinylhydrazone was synthesized and characterized. The interaction of native calf thymus DNA with isatin-3-isonicotinylhydrazone (IINH) in 10 mM Tris-HCl aqueous solutions at neutral pH 7.4 has been investigated by spectrophotometric, circular dichroism (CD), melting temperature (T ( m )), spectrofluorimetric, and viscometric techniques. It is found that IINH molecules could intercalate between base pairs of DNA as are evidenced by: hypochromism in UV absorption band of IINH, induced CD spectral changes, sharp increase in specific viscosity of DNA, and increase in the fluorescence of methylene blue (MB)-DNA solutions in the presence of increasing amounts of IINH, which indicates that it is able to release the intercalated MB completely. The binding constants of IINH-DNA complex at four different temperatures (277, 288, 298, and 310 K) were calculated to be 4.7 × 10(4), 2.2 × 10(4), 1.75 × 10(4) and 1.1 × 10(4) M(-1), respectively. Furthermore, the enthalpy and entropy of the reaction between IINH and CT-DNA showed that the reaction is enthalpy-favored and entropy- disfavored (∆H = -30.187 kJ mol(-1); ∆S = -20.46 J mol(-1)K(-1)) which are other evidences to indicate the IINH is able to be intercalated in the DNA base pairs.

Spectroscopic studies on the interaction of isatin with calf thymus DNA.

The interaction of native calf thymus DNA (CT-DNA) with isatin was studied at physiological pH by spectrophotometric, spectrofluorometric, competition experiment, circular dichroism, and viscometric techniques. No red shift and isobestic points are observed in UV absorption band of isatin. A strong fluorescence quenching reaction of DNA to isatin was observed, and the binding constants (Kf) of DNA with isatin and corresponding numbers of binding sites (n) were calculated at different temperatures. Thermodynamic parameters enthalpy change (ΔH) and entropy change (ΔS) were calculated to be +27.42 kJ mol⁻¹ and +201 J mol⁻¹ K⁻¹ according to Van't Hoff's equation, which indicated that the reaction is predominantly entropically driven. DNA viscosity and iodide quenching results suggest that isatin does not intercalate into the DNA base pairs. Circular dichroism spectra of CT-DNA indicated deep conformational changes in the DNA double helix. These results indicate that isatin interacts with CT-DNA via groove binding mode.