Near-Infrared PhotoInitiating Systems: Photothermal versus Triplet-Triplet Annihilation-Based Upconversion Polymerization.

NIR light-induced polymerization has attracted more and more attention in the photopolymerization field due to the possibility to use safer and more penetrating wavelengths, reducing the hazardousness. Here, a novel perspective for the free radical polymerization of acrylate-based monomers based on triplet-triplet annihilation upconversion (TTA-UC) is proposed, avoiding the introduction of heavy metals, usually required in the TTA processes. Thermal imaging experiments and Fourier transform infrared spectroscopy are respectively used to record the temperature during NIR irradiation and measure the reactive function conversion. The competition between the TTA-UC and the NIR photothermal activation is investigated to compare the relative efficiency of both NIR processes. In view of the results obtained by the different methods, the photothermal effect seems to get the upper hand over the photoactivation of the system.

Brassica rapa hairy root based expression system leads to the production of highly homogenous and reproducible profiles of recombinant human alpha-L-iduronidase.

The Brassica rapa hairy root based expression platform, a turnip hairy root based expression system, is able to produce human complex glycoproteins such as the alpha-L-iduronidase (IDUA) with an activity similar to the one produced by Chinese Hamster Ovary (CHO) cells. In this article, a particular attention has been paid to the N- and O-glycosylation that characterize the alpha-L-iduronidase produced using this hairy root based system. This analysis showed that the recombinant protein is characterized by highly homogeneous post translational profiles enabling a strong batch to batch reproducibility. Indeed, on each of the 6 N-glycosylation sites of the IDUA, a single N-glycan composed of a core Man3 GlcNAc2 carrying one beta(1,2)-xylose and one alpha(1,3)-fucose epitope (M3XFGN2) was identified, highlighting the high homogeneity of the production system. Hydroxylation of proline residues and arabinosylation were identified during O-glycosylation analysis, still with a remarkable reproducibility. This platform is thus positioned as an effective and consistent expression system for the production of human complex therapeutic proteins.

Production and secretion of a heterologous protein by turnip hairy roots with superiority over tobacco hairy roots.

A fully contained and efficient heterologous protein production system was designed using Brassica rapa rapa (turnip) hairy roots. Two expression cassettes containing a cauliflower mosaic virus (CaMV) 35S promoter with a duplicated enhancer region, an Arabidopsis thaliana sequence encoding a signal peptide and the CaMV polyadenylation signal were constructed. One cassette was used to express the green fluorescent protein (GFP)-encoding gene in hairy roots grown in flasks. A stable and fast-growing hairy root line secreted GFP at >120 mg/l culture medium. GFP represented 60 % of the total soluble proteins in the culture medium. Turnip hairy roots retained sustainable growth and stable GFP production over 3 years. These results were superior to those obtained using tobacco hairy roots.