Paul A. Bertin

Psa enzymatic activity: a new biomarker for assessing prostate cancer aggressiveness

With the advent of widespread prostate‐specific antigen (PSA) testing in recent decades, prostate cancer (PCa) has emerged as the most frequently diagnosed non‐skin cancer among men in the U.S. and Europe [1]. Greater screening rates coupled with improved detection methods have caused a controversial upsurge in the number of men undergoing prostate biopsy and subsequent treatment. However, current diagnostic techniques generally suffer from limited ability to identify which seemingly indolent cancers are biologically aggressive [2].

Synthesis and in vitro activity of ROMP-based polymer nanoparticles

A new type of polymer nanoparticle (PNP) containing a high density of covalently linked doxorubicin, attached via a non-cleavable amine linkage (amine-linked Dox-PNP) was prepared. Together with a previously reported cleavable carbamate-linked Dox-PNP, this new amine-linked Dox-PNP was subsequently evaluated against free doxorubicin for its cytotoxicity and inhibitory effects on SKNSH wild-type and SKrDOX6 doxorubicin-resistant human neuroblastoma cell lines. Analogous cholesterol-containing PNPs (Chol-PNPs) and indomethacin-containing PNPs (IND-PNPs) were also synthesized and used as the non-cytotoxic controls. While neither cell line was affected by Chol-PNPs or IND-PNPs, SKrDOX6 doxorubicin-resistant cells exhibited similar cytotoxic responses to free doxorubicin and both amine- and carbamate-linked Dox-PNPs, suggesting that doxorubicin or the doxorubicin-containing polymer must be the active agent in the latter case. SKNSH wild-type cells also responded to both Dox-PNPs, albeit at a higher apparent concentration than free doxorubicin alone. The growth of SKNSH wild-type cells was significantly inhibited upon incubation with carbamate-linked Dox-PNPs, as with free doxorubicin, over a 7-day period. In comparison to free doxorubicin, carbamate-linked Dox-PNPs produced a longer (72-h) period of initial inhibition in SKrDOX6 doxorubicin-resistant cells.

Ferrocene and Maleimide-Functionalized Disulfide Scaffolds for Self-Assembled Monolayers on Gold

A series of ferrocene-based electroactive molecules (EAMs) containing maleimide and disulfide groups in different asymmetric and branched architectures were designed and synthesized. Stable monolayers of each EAM on gold electrodes were confirmed by cyclic voltammetry. Importantly, these EAMs expand the repertoire of monolayer building blocks amenable to modular biofunctionalization for applications in electrochemical biosensor fabrication.

Electroactive self-assembled monolayers on gold via bipodal dithiazepane anchoring groups.

Novel dithiazepane-functionalized ferrocenyl-phenylethynyl oligomers 1 and 2 have been synthesized. Self-assembled monolayers (SAMs) of these ferrocene derivatives have been studied by X-ray photoelectron spectroscopy, ellipsometry, and cyclic voltammetry. It has been shown by XPS that monolayers of the dithiazepane-anchored molecules on gold electrodes contain gold-thiolate species. Cyclic voltammetry of the SAMs were characteristic of stable electroactive monolayers even for single-component SAMs of 1 and 2, with the more ideal responses recorded for the two-component SAMs diluted with undecanethiol. The small variation in peak splittings at progressively higher scan rates in these SAMs makes dithiazepane-bridged redox species promising candidates for further studies on molecular wires with bipodal anchoring.