Doxorubicin (DOX) was immobilized on gold nanoparticles (AuNPs) capped with carboxymethyl chitosan (CMC) for effective delivery to cancer cells. The carboxylic group of carboxymethyl chitosan interacts with the amino group of the doxorubicin (DOX) forming stable, non-covalent interactions on the surface of AuNPs. The carboxylic group ionizes at acidic pH, thereby releasing the drug effectively at acidic pH suitable to target cancer cells. The DOX loaded gold nanoparticles were effectively absorbed by cervical cancer cells compared to free DOX and their uptake was further increased at acidic conditions induced by nigericin, an ionophore that causes intracellular acidification. These results suggest that DOX loaded AuNPs with pH-triggered drug releasing properties is a novel nanotheraputic approach to overcome drug resistance in cancer.

Background: Multidrug-resistantAcinetobacter baumannii(MDRAB) is associated with nosocomial infections worldwide. To date, the use of a phage to prevent infections caused by MDRAB has not been demonstrated.Results: The MDRAB-specific phage ϕAB2 was stable at 4°C and pH 7 in 0.5% chloroform solution, and showed a slight decrease in plaque-forming units (PFU)/ml of 0.3–0.9 log after 330 days of storage. The addition of ϕAB2 at a concentration of at least 10⁵PFU/ml to anA. baumanniiM3237 suspension killed >99.9% ofA. baumanniiM3237 after 5 min, regardless ofA. baumanniiM3237 concentration (10⁴, 10⁵, or 10⁶colony-forming units (CFU)/ml). The addition of ϕAB2 at a concentration of 10⁸PFU/slide (>10⁷PFU/cm²) to glass slides containingA. baumanniiM3237 at 10⁴, 10⁵, or 10⁶CFU/slide, significantly reduced bacterial numbers by 93%, 97%, and 99%, respectively. Thus, this concentration is recommended for decontamination of glass surfaces. Moreover, infusion of ϕAB2 into 10% glycerol exhibited strong anti-MDRAB activity (99.9% reduction), even after 90 days of storage. Treatment of a 10% paraffin oil-based lotion with ϕAB2 significantly reduced (99%)A. baumanniiM3237 after 1 day of storage. However, ϕAB2 had no activity in the lotion after 1 month of storage.Conclusions: Phages may be useful for reducing MDRAB contamination in liquid suspensions or on hard surfaces. Phages may also be inoculated into a solution to produce an antiseptic hand wash. However, the phage concentration and incubation time (the duration of phage contact with bacteria) should be carefully considered to reduce the risk of MDRAB contamination.

A novel family of tetraaza macrocyclic Cu(II) complexes [CuLX₂] (where L = N₄ donor macrocyclic ligands) and (X = Cl⁻, NO₃⁻) have been synthesized and characterized by elemental analysis, magnetic moments, IR, EPR, mass, electronic spectra and thermal studies. The magnetic moments and electronic spectral studies suggest square planar geometry for [Cu(DBACDT)]Cl₂ and [Cu(DBACDT)](NO₃)₂ complexes and distorted octahedral geometry to the rest of the ten complexes. The biological activity of all these complexes against gram-positive and gram-negative bacteria was compared with the activity of existing commercial antibacterial compounds like Linezolid and Cefaclor. Six complexes out of twelve were found to be most potent against both gram-positive as well as gram-negative bacteria due to the presence of thio group in the coordinated ligands.