On Friday October 30, Sébastien DELPIERRE has defended his PhD thesis entitled “Self-Healable and Recyclable Polymer Networks Based on Dynamic Covalent Boroxine Chemistry”.
The PhD thesis jury was composed by Prof Davide Bonifazi (University of Vienna), Prof Guy Van Assche (Vrije Universiteit Brussel), Dr Sylvain Calloil (University of Montpellier), Prof Philippe Dubois (UMONS), Prof Roberto Lazzaroni (UMONS), Prof Jérôme Cornil (UMONS), Prof Jean-Marie Raquez (UMONS) and Prof Pascal Gerbaux.
In this work, we evaluate whether a relationship exists between the primary structures of synthetic homo and copolymers and their secondary structures as gaseous ions. IMS−MS experiments are further complemented by MD simulations. To highlight the effectiveness of IMS separation, we selected isomeric homo and copolymers made of lactide (LA) and propiolactone (PL) units. In this way, the mass analysis becomes useless since isomeric comonomer sequences can coexist for any given chain length. An UPLC method is implemented in the workflow to successfully separate all PL−LA comonomer sequences before infusion in the IMS−MS instrument. The analysis of doubly charged copolymers shows that the comonomer sequence has an impact on the IMS response. However, this only holds for copolymer ions with precise sizes and charge states, and this is therefore not a rule of thumb.
On Friday September 25, Quentin DUEZ has defended his PhD thesis entitled “Gas-Phase Structure of Polymer Ions : Ionization, Relaxation, and Implications for Structural Characterization”.
The PhD thesis jury was composed by Prof Claudio Zannoni (University of Bologna), Prof Carlos Afonso (Université de Rouen), Prof Philippe Dubois (UMONS), Dr Kevin Giles (Waters, UK), Prof Roberto Lazzaroni (UMONS), Prof Jérôme Cornil (UMONS), and Prof Pascal Gerbaux.
Quentin will now move for one year at the Radboud University in Nijmegen, as a post-doctoral researcher in the group of Prof Jana Roithova.
On Friday September 18, Emmanuel Colson – Manu – has defended his PhD thesis entitled “Green Waste Valorization : tuning the biological properties of horse chestnut and quinoa husk saponins by molecular engineering”.
The PhD thesis jury was composed by Prof Jean-Hugues Renault (Université de Reims, Champagne-Ardenne), Prof Maxence Wisztorski (Université de Lille), Prof Pierre Duez (UMONS), Prof Roberto Lazzaroni (UMONS), Prof Patrick Flammang (UMONS), and Prof Pascal Gerbaux.
Emmanuel will already start his new job in November, at the company “Quality Assistance” as a MS scientist.
On Friday September 11, Romain Liénard, PhD student at the Organic Synthesis Lab (S²MOs) and Polymer Lab (SMPC), has defended his PhD thesis entitled “Original Cyclo-based Macrostructures: Elaboration and Characterization” under the joint supervision of Olivier Coulembier and Julien De Winter.
The PhD thesis jury was composed of Prof Chrys Wesdemiotis (University of Akron, USA), Prof Scott Grayson (Tulane University, USA), Prof Pascal Gerbaux (UMONS), Prof Roberto Lazzaroni (UMONS), Dr Julien De Winter (S²MOs Lab, UMONS) and Prof Olivier Coulembier (SMPC Lab, UMONS).
Although the presentation conditions were unusual due to the sanitary restrictions, the jury points out, unanimously, that Mr. Romain Liénard exposed his research work in a very clear and didactic manner, which demonstrated his excellent communication skills.
A new paper entitled “Microwave-assisted depolymerization of carrageenans from Kappaphycus alvarezii and Eucheuma spinosum : controlled and green production of oligosaccharides from the algae biomass ” has been recently published in Algal research.
Algae biomass is nowadays considered as a unique reservoir of a huge variety of different molecules, such as lipids, carbohydrates, proteins and secondary metabolites, awaiting development in various fields. In particular, the valorization of the algae polysaccharide content is still in its infancy and intense research activity is starting to appear. Oligosaccharides with defined molecular weight and structures are extremely interesting for different applications such as plant biostimulation or biopesticide. Oligosaccharide are often prepared in medium to large scale upon chemical-based hydrolysis reactions from the extracted polysaccharides in harsh conditions (temperature and pH), leading to the loss of the fragile groups such as the sulfate functions in carrageenans. In the present work, microwave-based hydrolysis, as a green chemistry method, is optimized to produce bioactive oligosaccharides from carrageenans
A new paper entitled “Design of naturally inspired jellyfish-shaped cyclopolylactides to manage osteosarcoma cancer stem cells fate” has been recently published in Materials Science and Engineering: C.
We report the synthesis, characterization and biological profile of new bis-triazoled cyclo-(polylactide)s functionalized with folic acid (c-PLA-FA) or rhodamine (c-PLA-Rhod), obtained by an optimized combination of ROP and “click” chemistry reactions. Salinomycin (Sal) was loaded into jellyfish-shaped c-PLA-FA and c-PLA-Rhod nanoparticles (NPs) by nanoprecipitation, with a good encapsulation efficiency and loading content. The biological studies focused on their antiproliferative effects on osteosarcoma bulk MG63 and cancer stem cells (CSCs). The cyclo-PLA-based nanoparticles killed CSCs and MG63, with a higher efficacy on CSCs; they (unloaded or Sal-loaded) evoked on CSCs a cellular response similar to the payload, with a higher effect than the free Sal. Internalization studies indicated a fast cellular uptake (within 2 h). To the best of our knowledge, this is the first study reporting anti-CSCs properties of cyclo-PLA with jellyfish architecture and we believe could contribute to the development of effective strategies for osteosarcoma targeting.
The paper untitled “Enzymatic Polycondensation of 1,6-Hexanediol and Diethyl Adipate: A Statistical Approach Predicting the Key-Parameters in Solution and in Bulk” Discussed about enzymatic polycondensation of 1,6-hexanediol and diethyl adipate. The influence of various parameters including time, temperature, enzyme loading, and vacuum was assessed in the frame of a two-step polymerization with the help of response surface methodology, a statistical technique that investigates relations between input and output variables. Results in solution (diphenyl ether) and bulk conditions showed that a two-hour reaction time was enough to allow adequate oligomer growth for the first step conducted under atmospheric pressure at 100 ◦C. The number-average molecular weight (Mn) achieved varied between 5000 and 12,000 g·mol−1 after a 24 h reaction and up to 18,500 g·mol−1 after 48 h. In this study, mass spectrometry was used in order to characterized the structure of the newly synthetized polymers.
In this paper, we study the structure of different generations and charge states of PAMAM and PPI dendrimers in the gas phase by Ion Mobility Spectrometry and Molecular Dynamics. As the number of charges increases, the structure extents due to coulombic repulsion. For the lowest charge states, a globular structure can be assigned to the ions, allowing to calculate CCS-derived volume, surface and density. Those parameters are compared with MD geometrical data to characterize the structure of ions studied by Ion Mobility Spectrometry.
Fabrice Saintmont, Julien De Winter, Fabien Chirot, Emilie Halin, Philippe Dugourd, Patrick Brocorens, Pascal Gerbaux