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Borrelidin A (1) is produced by several species of Streptomyces and within its bioactive scaffold, the vinylic nitrile moiety is essential for activity. We report herein newly discovered members of the borrelidin family, borrelidin F (2), borrelidin G (3), borrelidin H (4) and borrelidin I (5); all were isolated from Streptomyces rochei SCSIO ZJ89 originating from a mangrove-derived sediment sample. These structurally diverse metabolites enabled a number of new structure-activity relationships (SARs) to be identified, especially with respect to the different configurations at the C11-OH and C12-C15 double bonds for which the absolute configurations were determined using spectroscopic methods. Importantly, borrelidin H (4) was found to have a therapeutic window superior to that of borrelidin A (1) in vitro and could inhibit migration of cancer cells., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Conventional enhanced permeation and retention (EPR) mediates the effects of many drugs, including the accumulation of nanocarriers at tumor sites, but its efficiency remains low. In this study, this limitation was overcome by developing a dual-targeting delivery system based on hyaluronan (HA, a major ligand of CD44) and tetraiodothyroacetic acid (tetrac, a specific ligand of αvβ3), which was exploited to carry docetaxel (DTX) for the synergistic active targeting to tumors. First, a tetrac-HA (TeHA) conjugate was synthesized and grafted onto the surfaces of solid lipid nanoparticles (SLNs) (TeHA-SLNs/DTX), with a high encapsulation efficiency of >91.6%. The resulting SLNs exhibited an approximately toroid morphology revealed using TEM. The cellular uptake and cytotoxicity of various formulations on CD44/αvβ3-enriched B16F10 cells were then assessed, and both results confirmed the selective uptake and high cytotoxicity of the TeHA-SLNs/DTX in a TeHA-dependent manner. In vivo imaging and vessel distribution tests revealed the efficiency of synergistic active targeting was higher than that of EPR-mediated passive targeting by the TeHA-SLNs to αvβ3-expressing tumor blood vessels and CD44-expressing tumor cells via selective targeting. Finally, in both xenograft tumor mice and in situ lung metastasis tumor mice, tumor growth was significantly inhibited by TeHA-SLNs/DTX. Therefore, TeHA-SLNs are an efficient system for the dual-targeted delivery of drugs to treat cancer in vivo., (Copyright © 2016 Elsevier B.V. All rights reserved.)

A co-loaded drug delivery system based on ascorbyl palmitate that can transport various functional drugs to their targets within a tumor represents an attractive strategy for increasing the efficiency of anticancer treatment. In this study, we developed a dual drug delivery system to encapsulate ascorbyl palmitate (AP) and paclitaxel (PTX) for synergistic cancer therapy. AP, which is a vitamin C derivative, and PTX were incorporated into solid lipid nanoparticles (AP/PTX-SLNs), which were used to treat murine B16F10 melanoma that had metastasized to the lungs of mice. These nanoparticles were spherical with an average size of 223 nm as measured by transmission electron microscope and dynamic light scattering.In vitrocytotoxicity assays indicated that the AP/PTX-SLNs with an AP/PTX mass ratio of 2/1 provided the optimal synergistic anticancer efficacy.In vivo, AP/PTX-SLNs were revealed to be much more effective in suppressing tumor growth in B16F10-bearing mice and in eliminating cancer cells in the lungs than single drug (AP or PTX)-loaded SLNs via a synergistic effect through reducing the Bcl-2/Bax ratio. Furthermore, no marked side effects were observed during the treatment with the AP/PTX-SLNs, indicating that the co-delivery system with ascorbyl palmitate holds promising clinical potential in cancer therapy. [ABSTRACT FROM AUTHOR]