Chemically denatured bovine serum albumin (dBSA)-coated water-soluble cadmium telluride (CdTe) quantum dots (QDs), which can effectively improve the chemical stability and photoluminescence quantum yield of CdTe QDs, were successfully conjugated to an anti-Escherichia coli antibody via a cross-linking reaction. The formation of antibody-conjugated CdTe QDs was confirmed using gel filtration chromatography. The anti-E. coli antibody-conjugated CdTe QDs were then used to detect E. coli O157:H7 and Listeria monocytogenes using fluorescence microscopy. It was shown that, after being conjugated to CdTe QDs, the anti-E. coli antibody still maintained its bioactivity and biorecognition specificity. Succinylated dBSA-coated CdTe QDs also were prepared to conjugate with the anti-E. coli antibody. However, no evidence was found that the succinylation provided a better route for antibody conjugation. Our results demonstrate the potential of bioconjugated CdTe QDs for broad biological applications, such as fluorescence-based pathogen detection and in vitro or in vivo cell imaging.

The inhibitory effects of inotilone and methylinotilone on the induction of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in murine RAW 264.7 cells activated with LPS were investigated. The results show that both hydroxyl groups on the benzene ring of the inotilone molecule are required for better anti-inflammatory effect. Western blotting and RT-PCR analyses demonstrated that inotilone blocked protein and mRNA expression of iNOS but not COX-2. Instead, inotilone inhibited prostaglandin E(2) production through decreasing the enzyme activity of COX-2. The repression of iNOS but not COX-2 expression may come from the differential effect of inotilone on nuclear factor-kappaB (NFkappaB) and CCAAT/enhancer-binding protein beta Treatment with inotilone resulted in the reduction of LPS-induced nuclear translocation of NFkappaB subunit and the NFkappaB-dependent transcriptional activity by blocking phosphorylation of inhibitor kappaB(IkappaB)alpha and p65 and subsequent degradation of inhibitor kappaBalpha. Inotilone also inhibited LPS-induced activation of PI3K/Akt and extracellular signal-regulated kinase 1/2 and p38 mitogen-activated protein kinase. Our results suggest that inotilone may have potential to be developed into an effective anti-inflammatory agent.