Neural Network-based Optimization of Silybum Marianum Extract-loaded Chitosan Particles: Modeling, Preparation and Antioxidant Evaluation.

BACKGROUND: Silymarin is a flavonolignan extracted from Silybum marianum with various therapeutic applications. Many studies have focused on improving the bioavailability of silymarin due to its wide range of efficacy and low bioavailability. Chitosan, a naturally occurring polymeric substance, has a strong reputation for increasing the solubility of poorly soluble compounds. OBJECTIVE: This study used artificial neural networks (ANNs) to measure the effects of pH, chitosan to silymarin ratio, chitosan to tripolyphosphate ratio, and stirring time on the loading efficiency of silymarin into chitosan particles. METHODS: A model was developed to investigate the interactions between input factors and silymarin loading efficiency. The DPPH method was utilized to determine the antioxidant activity of an optimized formula and pure raw materials. RESULTS: According to the outcome of the ANN model, pH and the chitosan to silymarin ratio demonstrated significant effects on loading efficiency. In addition, increased stirring time decreased silymarin loading, whereas the chitosan-to-tripolyphosphate ratio showed a negligible effect on loading efficiency. CONCLUSION: Maximum loading efficiency occurred at a pH of approximately~5. Moreover, silymarin- loaded chitosan particles with a lower IC50 value (36.17 ± 0.02 ppm) than pure silymarin (165.04 ± 0.07 ppm) demonstrated greater antioxidant activity.

Study of imidazole performance as pseudo-affinity ligand in the purification of IgG from bovine milk.

The spherical sepharose CL-6B beads were activated by epichlorohydrin in different epoxy contents (80, 120 and 160 µmolepoxide/mLgel) and, l-histidine and imidazole as pseudo-affinity ligands were covalently immobilized to them. Some linkers with different length, (1,2-ethanediol diglycidyl ether and 1,4-butanediol diglycidyl ether) were synthesized for activation of sepharose and the activated sepharose beads modified with imidazole and the performance of these adsorbents in the purification of immunoglobulin G from bovine milk were evaluated. Among the l-histidine bearing adsorbents, higher adsorption of IgG (0.28 mg/mL) was obtained by adsorbent with the lower concentration of l-histidine. The highest amount of IgG adsorption (0.53 mg/mL) was obtained by imidazole bearing adsorbent with the highest amount of imidazole and Among the adsorbents with synthesized linkers, the adsorbent with 1,2-ethanediol diglycidyl ether showed better performance and was able to purify 0.25 mg/mL IgG with high purity. The synthesized pseudo-affinity adsorbents represented the abbility to purify immunoglobulin G in one-step process with high purity and efficiency.

Magnetic iron oxide nanoparticles modified with vanadate and phosphate salts for purification of alkaline phosphatase from the bovine skim milk.

Modified Fe3O4 magnetic nanoparticles (magnetic nanocarrier) technology have found the proper place in separation and purification techniques, such as protein and enzyme purification, mostly due to its easy and fast operational procedure by using an external permanent magnet. Herein, Fe3O4 magnetic nanoparticles were prepared, and surface modification was performed with vanadate and phosphate salts to yield four various model of magnetic nanocarriers. Affinity ligands which are used for immobilization on the nanocarriers leading to the development of appropriative nanocarriers for the affinity separation of alkaline phosphatase from the bovine milk. The findings showed that the use of sodium hexametaphosphate affinity ligand attached to the carrier with an 18-atom linker leads to better separation of alkaline phosphatase from the bovine milk with 14.1-fold purification efficiency. All results confirmed that our designed nanocarriers can purify alkaline phosphatase using a fast and low-cost approach.

Preparation of p-aminophenol modified superparamagnetic iron oxide nanoparticles for purification of α-amylase from the bovine milk.

Currently, modified Fe3O4 magnetic nanoparticles frequently are used as nanocarriers for proteins and enzymes purification. In the present study, Fe3O4 magnetic nanoparticles were prepared, and their surfaces were modified with p-aminophenol affinity ligand immobilized by different linkers. The modified nanocarriers were used for the purification of α-amylase from the bovine milk (after precipitation the casein) by affinity purification. To evaluate the effectiveness of the p-aminophenol modified magnetic nanocarriers, the three different types of nanocarriers with different linkers having varying lengths were prepared. All nanocarriers were characterized and validated using FT-IR, SEM, EDX, VSM and XRD analysis methods According to our results, p-aminophenol ligand attached to the nanocarrier by long linkers better separates the α-amylase from the casein free skim milk with 49.66% recovery and 48.18-fold purification efficiency. The results of this study showed that our novel magnetic nanocarriers have the capacity to be used for fast, reproducible and cost-effective purification of α-amylase.

Arsanilic acid modified superparamagnetic iron oxide nanoparticles for Purification of alkaline phosphatase from hen's egg yolk.

Recent studies of magnetic carrier technology have focused on its applications in separation and purification technologies, due to easy separation of the target from the reaction medium by applying an external magnetic field. In the present study, Fe3O4 superparamagnetic nanoparticles were prepared to utilize a chemical co-precipitation method, then the surfaces of the nanoparticles were modified with arsanilic acid derivatives which were used as the specific nanocarriers for the affinity purification of alkaline phosphatase from the hen's egg yolk. The six different types of magnetic nanocarriers with varied lengths of the linkers were obtained. All samples were characterized step by step and validated using FTIR, SEM, EDX, VSM and XRD analysis methods As the results were shown, the use of inflexible tags with long linkers on the surface of the nanocarrier could lead to better results for separation of alkaline phosphatase from the hen's egg yolk with 76.2% recovery and 1361.7-fold purification. The molecular weight of the purified alkaline phosphatase was estimated to be 68kDa by SDS-PAGE. The results of this study showed that the novel magnetic nanocarriers were capable of purifying alkaline phosphatase in a practically time and cost effective way.

Study of the Cytotoxic and Bactericidal Effects of Sila-substituted Thioalkyne and Mercapto-thione Compounds based on 1,2,3-Triazole Scaffold.

A series of sila-organosulphur compounds containing 1,2,3-triazole cores were screened for their cytotoxic activity on human breast cancer cell line MCF-7. Most of the tested compounds exhibited moderate-to-good activity against the cancer cells. Especially, the compound 4-((2-(trimethylsilyl)ethynylthio)methyl)-1-benzyl-1H-1,2,3-triazole (3a) from series of sila-substituted thioalkyne 1,2,3-triazoles (STATs) and the compounds 3-(1-benzyl-1H-1,2,3-triazol-4-yl)-1-mercapto-1,1-bis(trimethylsilyl)propane-2-thione (4a) and 1-mercapto-1,1-bis(trimethylsilyl)-3-(1-phenethyl-1H-1,2,3-triazol-4-yl)propane-2-thione (4e) from series of sila-substituted mercapto-thione 1,2,3-triazoles (SMTTs) exhibited promising cytotoxicity against MCF-7 with IC50 values of 35.17, 32.63 and 30.3 µg/mL, respectively. In addition, the possible mechanisms for inhibition of cell growth and induction of apoptotic cell death were explored by DAPI staining, cell cycle analysis and qRT-PCR. The synthetic compounds were evaluated for their in vitro antibacterial activities, and as a result, the most prominent effects were observed for 3e and 4e. Especially, 3e was found to be quite active against all the tested strains with the MIC values ranging from 15 to 62 µg/mL, except P. aeruginosa. The results of the time-kill assay suggested that the compound of 3e completely inhibited the growth of both gram-negative bacteria, A. baumannii, and gram-positive bacteria, S. aureus. In addition, SEM analysis confirmed morphostructural damage of the bacteria. Our findings could be applicable for developing dual-targeting anticancer/antibacterial therapeutics.

Synthesis of novel organosilicon compounds possessing highly substituted imidazole core catalyzed by antimony trioxide.

A general synthetic route for the exclusive preparation of tetrasubstituted imidazoles, possessing benzylic methyl groups has been developed using Sb2O3 via solvent-free, one-pot reaction conditions. Detailed results from our investigation on the bromination of the benzylic methyl groups of imidazoles are described. The products generated during this study were utilized as substrates for the synthesis of organosilicon-containing imidazoles. Synthesis of tris(triorganosilyl)methylimidazole derivatives was carried out using organolithium reagents (RSiMe2)3CLi, (R= H, Me, Ph) prepared via metalation of (RSiMe2)3CH with lithiumdiisopropylamide or methyllithium in THF, in excellent yields. (RSiMe2)3CLi, (R= Me, Ph) were treated with formylated imidazole to afford imidazole containing 2,2-bis(organosilyl)ethenyl groups. 2-(4-(2,2-bis(trimethylsilyl)vinyl)phenyl)-1,4,5-triphenyl-1H-imidazole was obtained via Peterson reaction in high yield. However, compound 2-(4-(2,2-bis(dimethyl(phenyl)silyl)vinyl)phenyl)-1,4,5-triphenyl-1H-imidazole was obtained in low yield likely because of the steric hindrance of the (PhSiMe2)3C- group.