Polymer Chemistry Blog

Prof. Jacques Lalevée was born in Remiremont (France) in 1976. After studying Physical Chemistry at the University of Nancy (now University of Lorraine), he received his Ph.D. degree in Materials Chemistry under the supervision of Prof. Jean Pierre Fouassier from Mulhouse in 2002. After approximately one-year of postdoctoral research with Prof. Gerd Kothe (Germany), he joined the “Ecole Nationale Supérieure de Chimie de Mulhouse (ENSCMu)” in September, 2004. He was promoted to full professor in September, 2009. Since 2011, Jacques has been a Professor at the “Institut Universitaire de France (IUF-Paris)”. His current research interests encompass free radical chemistry, the design of new (photo)polymerisation initiating systems and new polymers, as well as mechanistic elucidation in polymer chemistry. He has published nearly 200 peer-reviewed papers with an H-index of 29.

He was awarded the Guy Ourisson 2013 Prize as well as the national prize of the French polymer group (GFP) in 2014.

What was your inspiration in becoming a chemist?

I became really interested in chemistry at high school. I was fascinated by chemical reactions and the possibility of understanding events at this molecular scale. I have always been interested in free radical chemistry as many different reaction pathways can be expected from these chemical species. The “positive” use of free radicals in polymerisation processes was always a challenge for me; particularly the possibility of triggering processes by light for perfect time and spatial controls.

What was the motivation to write your Polymer Chemistry article?

Light-induced polymerisation technique is a promising approach for the fabrication of various polymeric materials due to its environmental, economic and production benefits. This technique is mainly based on the photochemically generated reactive species (e.g. radicals or cations, produced from the photochemical reactions of photoinitiating systems after the absorption of light) to rapidly transform the specially formulated reactive liquids to solids (3D polymeric networks for various materials) at room temperature. Recently, light-emitting diodes (LEDs) have attracted increased attention as potential irradiation sources for photopolymerisation processes substituting traditional mercury UV lamps; their advantages include being more environmentally friendly, having better light output, higher operating efficiency and lower cost and energy consumption.

Recently, the use of metal based complexes as photoredox catalysts in polymer science has generated lots of interest and is actually a huge challenge. In the present paper, we propose a new iridium complex (Ir(btp)₂(tmd)) as a novel photoredox catalyst with enhanced efficiency under visible lights (laser diodes, LEDs and household halogen lamp) for i) cationic polymerisation, ii) free radical polymerisation, iii) controlled/living radical polymerisation and iv) polymer surface modification, including micropatterning by laser direct writing.

Why did you choose Polymer Chemistry to publish your work?

The Royal Society of Chemistry is clearly one of the leading societies and accordingly its polymer journal “Polymer Chemistry” has rapidly emerged as a leader journal in Polymer Science. The wide international readership, the quick submission and review system are also particularly interesting.

In which upcoming conferences may our readers meet you?

The European Polymer Congress (Dresden, Germany in June 2015) or 11^th International Symposium on Ionic Polymerization (Bordeaux – France July 2015).

How do you spend your spare time?

Obviously, I am willing to spend more time with my family. I like cycling, and would like to dedicate more time to it.

Which profession would you choose if you were not a scientist?

I would become a teacher in middle school, it was my original idea, but I met excellent professors in the University and they have opened my mind to research.

Photoredox catalysis using a new iridium complex as an efficient toolbox for radical, cationic and controlled polymerizations under soft blue to green lights

Sofia Telitel, Frederic Dumur, Siham Telitel, Olivier Soppera, Marc Lepeltier, Yohann Guillaneuf, Julien Poly, Fabrice Morlet-Savary, Philippe Fioux, Jean-Pierre Fouassier, Didier Gigmes and Jacques Lalevée

A new iridium complex (nIr) was designed and investigated as a photoinitiator catalyst for radical and cationic polymerization upon very soft irradiations (lights ranging from 457 to 532 nm). A ring-opening polymerization (ROP) of an epoxy monomer was easily promoted through the interaction between nIr and an iodonium salt (Iod) upon light. In radical polymerization, nIr can be efficient in combination with phenacyl bromide (PBr) and optionally an amine. These photoinitiating systems work according to an original oxidative cycle and a regeneration of nIr is observed. A control of the methyl methacrylate polymerization (conducted under a 462 nm light) with 1.2–1.6 polydispersity indexes was displayed. Surface modifications by direct laser write was also easily carried out for the first time through surface re-initiation experiments, i.e. the dormant species being reactivated by light in the presence of nIr; the polymer surfaces were analyzed by XPS. The chemical mechanisms were examined through laser flash photolysis, NMR, ESR and size exclusion chromatography experiments.

Cyrille Boyer is a guest web-writer for Polymer Chemistry. He is currently an Associate Professor and an ARC-Future Fellow in the School of Chemical Engineering, University of New South Wales (Australia).

Anthony studied Chemistry at Edison College in Southwest Florida before transferring to the University of Southern Mississippi where he obtained his BS and PhD in Polymer Science and Engineering.  Under the supervision of his advisor, Professor Charles McCormick, he worked on preparing water-soluble polymers by RAFT polymerization.  Following the completion of his PhD studies he moved to Seattle Washington to do a postdoc with Professor Patrick Stayton and Allan Hoffman.  During his postdoc he worked on applying RAFT synthetic methodology to develop polymeric materials for delivering biologic drugs.  Following his postdoc, he took a position as a research assistant professor in the department of BioEngineering at the University of Washington.  To date Anthony has publish almost 60 research articles and patents and developed technology that has led to the establishment of a local area start up company.

His research is focused primarily on the application of controlled free radical polymerization and thiol-ene/Michael chemistry to develop powerful new delivery technologies that will enable the realization of therapies based on intracellularly active biologic drugs. These agents have the potential to revolutionize the treatment of serious diseases such as cancer and antibiotic resistant bacteria while minimizing harmful side effects.

What was your inspiration in becoming a chemist?

I think that I have always wanted to become a chemist.  From a very early age I enjoyed mixing whatever chemicals I could find to see what would happen. When I first started college I was required to take several chemistry classes as part of the pre-pharmacy curriculum. Along the way my organic chemistry instructor, Professor Scott, really inspired me to change my major to chemistry. His lab courses were fascinating and I was really intrigued by the idea that complex organic molecules could be made to react in deliberate ways. Soon after that I took a polymer chemistry course by Professor McCormick, who would later become my PhD advisor, which really sparked my imagination and cemented my desire to be a chemist.

What was the motivation to write your Polymer Chemistry article ?

The starting point for writing this article was the desire to create a new class of drug delivery system that could combine the high drug loading capacity and well defined structure of polymer-drug conjugates with the long circulation times of nanoparticle-based systems. Controlled radical polymerization methodologies, including the versatile reversible addition–fragmentation chain transfer (RAFT) polymerization process, are rapidly moving to the forefront in construction of drug delivery vehicles. The use of RAFT polymerization from multifunctional scaffolds provided a scientifically interesting approach for preparing these materials with spatially defined biofunctional segments.

Why did you choose Polymer Chemistry to publish your work?

Polymer chemistry is quickly becoming the premier journal for publishing cutting edge polymer science research across a range of polymer-related disciplines. The editors at Polymer Chemistry do a great job of making the manuscript figures and layouts look really sharp.  We are really excited about this work and felt that Polymer Chemistry would give our manuscripts excellent visibility. The work detailed in this manuscript was conducted along side a second closely related study so it made a lot of sense to publish them together.

In which upcoming conferences may our readers meet you?

We recently presented this work at the 2014 Zing Polymer Chemistry Conference in Cancun Mexico.  We are planning to attend the 2015 BMES meeting in Tampa, Florida.

How do you spend your spare time?

The Pacific Northwest is just amazing! There are so many natural wonders here that there is always a new hike to go on or a spectacular coastline to explore. I am also an aspiring surfer and take every opportunity to head down to the California coast to catch some waves. In the summer I like to head back to my hometown in Southwest Florida to fish for redfish with my cousin.  The mangrove shorelines and grassy flats have some of the best fishing in the world and are uniquely beautiful.  During football season you can usually find me at the local pub rooting for the Seattle Seahawks.

Which profession would you choose if you were not a chemist?

Pharmacist. Medicinal compounds and their affect on the human body have always fascinated me.

Well-defined single polymer nanoparticles for the antibody-targeted delivery of chemotherapeutic agents

D. D. Lane,   D. Y. Chiu,  F. Y. Su,   S. Srinivasan,   H. B. Kern,   O. W. Press,   P. S. Stayton and   A. J. Convertine

Aqueous reversible addition-fragmentation chain transfer (RAFT) polymerization was employed to prepare a series of linear copolymers of N,N-dimethylacrylamide (DMA) and 2-hydroxyethylacrylamide (HEAm) with narrow Đ values over a molecular weight range spanning three orders of magnitude (10³ to 10⁶ Da). Trithiocarbonate-based RAFT chain transfer agents (CTAs) were grafted onto these scaffolds using carbodiimide chemistry catalyzed with DMAP. The resultant graft chain transfer agent (gCTA) was subsequently employed to synthesize polymeric brushes with a number of important vinyl monomer classes including acrylamido, methacrylamido, and methacrylate. Brush polymerization kinetics were evaluated for the aqueous RAFT polymerization of DMA from a 10 arm gCTA. Polymeric brushes containing hydroxyl functionality were further functionalized in order to prepare 2nd generation gCTAs which were subsequently employed to prepare polymers with a brushed-brush architecture with molecular weights in excess of 10⁶ Da. The resultant single particle nanoparticles (SNPs) were employed as drug delivery vehicles for the anthracycline-based drug doxorubicin via copolymerization of DMA with a protected carbazate monomer (bocSMA). Cell-specific targeting functionality was also introduced via copolymerization with a biotin-functional monomer (bioHEMA). Drug release of the hydrazone linked doxorubicin was evaluated as function of pH and serum and chemotherapeutic activity was evaluated in SKOV3 ovarian cancer cells.

Cyrille Boyer is a guest web-writer for Polymer Chemistry. He is currently an associate professor and an ARC-Future Fellow in the School of Chemical Engineering, University of New South Wales (Australia), deputy director of the Australian Centre for NanoMedicine and member of Centre for Advanced Macromolecular Design.