Peptide photowrapping of gold-silica nanocomposites for constructing MMP-responsive drug capsules for chemo-photothermal therapy.

A multifunctional undecapeptide, YYDPLGLADYY, was designed and synthesized for the photowrapping of silica-coated gold nanorods. The obtained nanocapsules, bearing a well-defined core-shell structure, were able to encapsulate a therapeutic drug, respond to an MMP-upregulated tumor microenvironment, and achieve NIR-triggered anticancer chemo-photothermal therapy with favorable efficacy.

Luminescence-Tunable Polynorbornenes for Simultaneous Multicolor Imaging in Subcellular Organelles.

Through modular ROMP (ring-opening metathesis polymerization), biofunctional polynorbornenes are designed and fabricated from panchromatic fluorophores, bioactive peptides, and polyethylene glycol solubilizer for organelle-specific multicolor imaging. Attributed to the free permutation and combination of highly fluorescent red rhodamine B, green dichlorofluorescein and blue 9,10-diphenylanthracene fluorophores as well as signaling peptide sequences of F xrF xK and TAT, we successfully realize simultaneous multicolor imaging toward lysosomes and mitochondria in living cells first utilizing polymeric scaffolds. If more biofunctions could be incorporated, modularly designed copolymer would provide a promising opportunity to facilitate multitasking application to monitoring intracellular alterations and elucidating complex biological processes.

Inhibition of cytochrome P450 enzymes by rhein in rat liver microsomes.

Rhein, an active ingredient extensively found in plants such as Aloe, Cassitora L., rhubarb and so on, has been used for a long time in China. Pharmacological tests revealed that rhein not only had a strong antibacterial action, but also may be useful in cancer chemotherapy as a biochemical modulator. Its therapeutic action and toxicity is still the subject of considerable research. With microsome incubation assays in vitro and HPLC methods, the inhibition of rat liver CYP1A2, CYP2C9, CYP2D6, CYP2E1 and CYP3A enzymes by rhein were studied kinetically. The results showed the most inhibition of CYP2E1 by rhein (K(i) = 10 microm, mixed); CYP3A and CYP2C9 were also inhibited by rhein, K(i) = 30 microm (mixed) and K(i) = 38 microm (mixed), respectively; rhein revealed some inhibition of CYP1A2 (K(i) = 62 microm, uncompetitive) and CYP2D6 (K(i) = 74 microm, mixed). Drug-drug interactions, especially cytochrome P450 (CYP)-mediated interactions, cause an enhancement or attenuation in the efficacy of co-administered drugs. Inhibition of the five major CYP enzymes observed for rhein suggested that changes in pharmacokinetics of co-administered drugs were likely to occur. Therefore, caution should be paid to the possible drug interaction of medicinal plants containing rhein and CYP substrates.