Tumour-specific hybrid nanoparticles in therapy of breast cancer

In this study, salicylic acid (SA) dopped into poly(3-hydroxybutyrate) (PHB) and prepared nanoparticles (NPs) to increase encapsulation efficiency, anti-cancer activity of caffeic acid (Caff), and folic acid (FA) for breast cancer treatment. NPs were prepared by solvent evaporation method and characterised by FTIR, DSC, SEM, and entrapment-loading efficiencies. The mean diameter, polydispersity index (PDI), and zeta potential (ZP) were evaluated by dynamic light scattering (DLS). In vitro release and stability studies were done via eppendorf method. The cytotoxicity, cell dead and internalisation of NPs were shown by MTT, fluorescein and confocal microscopy. The diameter and ZP of NPs were 172 ± 7 nm and -29 ± 0.38 mV. The entrapment efficiencies of 5 and 10 Caff NPs were 79 ± 0.23% and 70 ± 0.42%. NPs showed good stability within 30 d and sustained release over 25 d. FA-5Caff NPs showed 37 ± 0.3% viability on MCF-7. FA-Caff NPs were identified as promising carrier system for breast cancer therapy.

Prevention of urinary infection through the incorporation of silver-ricinoleic acid-polystyrene nanoparticles on the catheter surface

Nosocominal infections associated with biofilm formation on urinary catheters cause serious complications. The aim of this study was to investigate the feasibility of the polyurethane (PU) catheter modified with tetracycline hydrochloride (TCH) attached Ag nanoparticles embedded PolyRicinoleic acid-Polystyrene Nanoparticles (PU-TCH-AgNPs-PRici-PS NPs) and the influence on antimicrobial and antibiofilm activity of urinary catheters infected by Escherichia coli and Staphylococcus aureus. For this purpose, AgNPs embedded PRici graft PS graft copolymers (AgNPs-PRici-g-PS) were synthesized via free radical polymerization and characterized by FTIR, HNMR and DSC. AgNPs-PRici-PS NPs were prepared and optimized by the different parameters and the optimized size of nanoparticle was found as about 150 ± 1 nm. The characterization of the nanoparticles and the morphological evaluation were carried out by FTIR and SEM. Short term stability of nanoparticles was realised at 4°C for 30 days. In vitro release profiles of TCH and Ag NPs were also investigated. The formation of biofilm on PU modified TCH-Ag NPs-PRici-PS NPs, was evaluated and the biocompatibility test of the nanoparticles was realized via the mouse fibroblast (L929) and mouse urinary bladder cells (G/G An1). This is the first time that TCH-AgNPs-PRici-PS NPs used in the modification of PU catheter demonstrated high antimicrobial and antibiofilm activities against the urinary tract infection.

A Comparative Study of Receptor-Targeted Magnetosome and HSA-Coated Iron Oxide Nanoparticles as MRI Contrast-Enhancing Agent in Animal Cancer Model

Magnetosomes are specialized organelles arranged in intracellular chains in magnetotactic bacteria. The superparamagnetic property of these magnetite crystals provides potential applications as contrast-enhancing agents for magnetic resonance imaging. In this study, we compared two different nanoparticles that are bacterial magnetosome and HSA-coated iron oxide nanoparticles for targeting breast cancer. Both magnetosomes and HSA-coated iron oxide nanoparticles were chemically conjugated to fluorescent-labeled anti-EGFR antibodies. Antibody-conjugated nanoparticles were able to bind the MDA-MB-231 cell line, as assessed by flow cytometry. To compare the cytotoxic effect of nanoparticles, MTT assay was used, and according to the results, HSA-coated iron oxide nanoparticles were less cytotoxic to breast cancer cells than magnetosomes. Magnetosomes were bound with higher rate to breast cancer cells than HSA-coated iron oxide nanoparticles. While 250 μg/ml of magnetosomes was bound 92 ± 0.2%, 250 μg/ml of HSA-coated iron oxide nanoparticles was bound with a rate of 65 ± 5%. In vivo efficiencies of these nanoparticles on breast cancer generated in nude mice were assessed by MRI imaging. Anti-EGFR-modified nanoparticles provide higher resolution images than unmodified nanoparticles. Also, magnetosome with anti-EGFR produced darker image of the tumor tissue in T2-weighted MRI than HSA-coated iron oxide nanoparticles with anti-EGFR. In vivo MR imaging in a mouse breast cancer model shows effective intratumoral distribution of both nanoparticles in the tumor tissue. However, magnetosome demonstrated higher distribution than HSA-coated iron oxide nanoparticles according to fluorescence microscopy evaluation. According to the results of in vitro and in vivo study results, magnetosomes are promising for targeting and therapy applications of the breast cancer cells.

EGF Loaded Chitosan Sponges as Wound Dressing Material

The aim of this study was to prepare and characterize chitosan sponges using epidermal growth factor (EGF) for wound healing. Chitosan sponges were prepared by solvent evaporation (or precipitation) combined with chemical cross-linking techniques. The chitosan polymer was weighed and dissolved in aqueous acetic acid solution (5% v/v) and injected into absolute ethanol containing a cross-linker (ethylene glycol diglycydyl ether). The growth factor (EGF) was loaded into sponges by adding it into the chitosan solution. The EGF loaded chitosan sponges were used in fibroblast cell culture studies to investigate the effects of EGF released on cell proliferation and to determine the effects of the different variables on EGF release; such as, chitosan Mw, cross-linker, the needle injecting the chitosan solution into the precipitation medium, chitosan/EGF ratio and pH of the medium. The swelling of the sponges was higher in the lower molecular weight chitosan, with less cross-linker and using a small diameter injection needle. The swelling increased with decreasing chitosan/EGF ratio and the EGF release rate was increased by increasing the sponge swelling. The cell proliferation (cell growth) increased with increasing swelling ratio.

Regulation of tumor angiogenesis by EZH2

Although VEGF-targeted therapies are showing promise, new angiogenesis targets are needed to make additional gains. Here, we show that increased Zeste homolog 2 (EZH2) expression in either tumor cells or in tumor vasculature is predictive of poor clinical outcome. The increase in endothelial EZH2 is a direct result of VEGF stimulation by a paracrine circuit that promotes angiogenesis by methylating and silencing vasohibin1 (vash1). Ezh2 silencing in the tumor-associated endothelial cells inhibited angiogenesis mediated by reactivation of VASH1, and reduced ovarian cancer growth, which is further enhanced in combination with ezh2 silencing in tumor cells. Collectively, these data support the potential for targeting ezh2 as an important therapeutic approach.

ANTIMICROBIAL ACTIVITY OF CEFAZOLIN-IMPREGNATED MESH GRAFTS

BACKGROUND

The aim of this study is the preparation and characterization of cefazolin-impregnated meshes (Surgipro; Tyco Healthcare USSC, Norwalk, CT, USA) to be used as antimicrobial devices.

METHODS

During the impregnation, poly(DL-lactide-co-glycolide) solution with cephazolin in dichloromethane was used as coating material. In vitro release experiment was carried out first; later cefazolin-impregnated meshes were evaluated for the characteristics of antimicrobial efficacy and in the last part of the study native and cefazolin-impregnated meshes were implanted in the rats. Cefazolin content was proposed as the effective parameter to control the cefazolin release rate and it was concluded that the higher amounts of initial cefazolin content caused higher release rates. In all cases (or with different cefazolin content for each mesh), the release rates were very rapid in the first 24 h and in the following periods rather slow release rates were obtained.

RESULTS

Antimicrobial activity was increased in the case of cefazolin-impregnated form and this efficiency was also increased by the higher amount of cefazolin in certain mesh pieces. Similar antimicrobial activities were observed in the in vitro studies.

CONCLUSION

In this study, almost all of the cefazolin-impregnated mesh grafts showed very high antimicrobial activity compared with the bare mesh (or mesh without cefazolin).