Use of biotin targeted methotrexate-human serum albumin conjugated nanoparticles to enhance methotrexate antitumor efficacy.

Biotin molecules could be used as suitable targeting moieties in targeted drug delivery systems against tumors. To develop a biotin targeted drug delivery system, we employed human serum albumin (HSA) as a carrier. Methotrexate (MTX) molecules were conjugated to HSA. MTX-HSA nanoparticles (MTX-HSA NPs) were prepared from these conjugates by cross-linking the HSA molecules. Biotin molecules were then conjugated on the surface of MTX-HSA NPs. The anticancer efficacy of biotin targeted MTX-HSA NPs was evaluated in mice bearing 4T1 breast carcinoma. A single dose of biotin targeted MTX-HSA NPs showed stronger in vivo antitumor activity than non-targeted MTX-HSA NPs and free MTX. By 7 days after treatment, average tumor volume in the biotin targeted MTX-HSA NPs-treated group decreased to 17.6% of the initial tumor volume when the number of attached biotin molecules on MTX-HSA-NPs was the highest. Average tumor volume in non-targeted MTX-HSA NPs-treated mice grew rapidly and reached 250.7% of the initial tumor volume. Biotin targeted MTX-HSA NPs increased the survival of tumor-bearing mice to 47.5 ± 0.71 days and increased their life span up to 216.7%. Mice treated with biotin targeted MTX-HSA NPs showed slight body weight loss (8%) 21 days after treatment, whereas non-targeted MTX-HSA NPs treatment at the same dose caused a body weight loss of 27.05% ± 3.1%.

Enhanced anti-tumoral activity of methotrexate-human serum albumin conjugated nanoparticles by targeting with Luteinizing Hormone-Releasing Hormone (LHRH) peptide.

Active targeting could increase the efficacy of anticancer drugs. Methotrexate-human serum albumin (MTX-HSA) conjugates, functionalized by luteinizing hormone-releasing hormone (LHRH) as targeting moieties, with the aim of specifically targeting the cancer cells, were prepared. Owing to the high expression of LHRH receptors in many cancer cells as compared to normal cells, LHRH was used as the targeting ligand in this study. LHRH was conjugated to MTX-HSA nanoparticles via a cross-linker. Three types of LHRH targeted nanoparticles with a mean particle size between 120-138 nm were prepared. The cytotoxicity of LHRH targeted and non-targeted nanoparticles were determined on the LHRH positive and negative cell lines. The internalization of the targeted and non-targeted nanoparticles in LHRH receptor positive and negative cells was investigated using flow cytometry analysis and fluorescence microscopy. The cytotoxicity of the LHRH targeted nanoparticles on the LHRH receptor positive cells were significantly more than non-targeted nanoparticles. LHRH targeted nanoparticles were also internalized by LHRH receptor positive cells significantly more than non-targeted nanoparticles. There were no significant differences between the uptake of targeted and non-targeted nanoparticles to the LHRH receptor negative cells. The active targeting procedure using LHRH targeted MTX-HSA nanoparticles could increase the anti-tumoral activity of MTX.

Comparison of the microshear bond strength of feldspathic porcelain to enamel with three luting resins.

PURPOSE: The purpose of this study was to compare microshear bond strength of three different luting resins using a new microshear method closely simulating clinical condition. METHODS: Thirty 1-mm-thick slices of intact human first molars and thirty 0.8-mm-diameter feldspathic porcelain rods were etched by 37% phosphoric acid for enamels and 9.5% hydrofluoric acid for porcelains. Adhesive (Margin bond) was applied on both silaned porcelain and enamel surfaces. Three luting agents were used as follows: (1) dual polymerized cement (DP) (Variolink II refill), (2) light polymerized cement (LP) (Variolink II base), and (3) flow composite (FC) (Tetrick flow). Porcelain rods were attached to flat enamel surfaces followed by cementation. The specimens were thermal cycled for 500 cycles between 5 and 55°C, and microshear test was then performed with wire and loop method using Dillon Quantrol. Modes of failure were identified by stereomicroscope, and one sample of each group was observed with SEM. finally collected data were statistically analyzed using one-way ANOVA (P<.05). RESULTS: The mean microshear bond strengths were 21.48 (DP), 23.92 (LP) and 24.57 (FC) in MPa units. Most cohesive failures occurred in groups LP and FC, whereas most adhesive failures were observed in group DP. CONCLUSION: Bond strength of feldspathic porcelain to enamel with studied luting resins were not significantly different among the groups based on current method (P<.05).

Targeted delivery of methotrexate to tumor cells using biotin functionalized methotrexate-human serum albumin conjugated nanoparticles.

Systemic toxicity following cancer chemotherapy is an important concern. Targeted drug delivery systems could reduce the toxicity of anticancer drugs. Vitamins have been considered as targeting moieties in novel cancer treatment strategies. In this study, biotin was attached to nanoparticles of conjugated methotrexate-human serum albumin. Biotin functionalized methotrexate-human serum albumin with three different amounts of biotin attached to the nanoparticles were prepared. It was shown that the cytotoxicity of biotin functionalized nanoparticles on T47D and HeLa tumor cells was significantly higher than that of free methotrexate and non-functionalized nanoparticles. The cytotoxicity of biotin functionalized nanoparticles further increased when the number of biotin molecules attached on the surface of nanoparticles increased. The uptake of FITC labeled biotin functionalized nanoparticles by T47D and HeLa cells measured by flow cytometry, was also higher than that of non-functionalized nanoparticles. It can be concluded that the biotin functionalized methotrexate-human serum albumin conjugated nanoparticles could be used as a potent drug for specific delivery of methotrexate to tumors.