Biology subjects

Serre, C.

Publications and source records attributed to Serre, C..

3 recordsLinked to original sources

bioRxiv2024

Yttrium-90-doped metal-organic frameworks (MOFs) for low-dose rate intratumoral radiotherapy

Brachytherapy, or intratumoral radiation therapy, is a highly effective treatment option for localized tumors. Herein, we engineered injectable and biodegradable metal-organic frameworks (MOFs) to deliver the therapeutic radioisotope yttrium-90 (90Y). Particles of bimetallic MIL-100(Fe,Y) and Y-BTC, doped with 90Y and 88Y, were synthesized in a single step and retained radioyttrium in various buffer solutions. Tumor injectability and radioisotope retention were evaluated using tumor-bearing mice. In vivo analysis and calculations showed that radiolabeled MIL-100(Fe,Y) emitted more than 38% of its radioactivity, while Y-BTC emitted greater than 75% of its radioactivity, through 7 days at the tumor site upon intratumoral injection, without significant yttrium accumulation in off-target tissues. The anticancer effects of MIL-100(Fe,Y,90Y) and 90Y,Y-BTC particles were assessed using 3D multicellular tumor spheroids and a tumor-bearing mouse model, respectively. 90Y-doped MIL-100(Fe,Y) particles penetrated A549 tumor spheroids and caused superior cytotoxic effects compared to non-radioactive particles or 90YCl3, added at the same dose. Brachytherapy with 90Y-doped Y-BTC MOFs induced inhibition of B16F1 melanoma tumor growth and resulted in an increased median survival of 8.5 days compared to 4.5 days in untreated mice. This study exhibits the feasibility to prepare radioactive 90Y-containing biodegradable, non-toxic MOF particles that are advantageous for low-dose rate internal radiotherapy.

biophysics↗

bioRxiv2024

Differential warming at crown scale impacts walnut primary growth onset and secondary growth rate

Trees are exposed to significant spatio-temporal thermal variations, which can induce intracrown discrepancies in the onset and dynamics of primary and secondary growth. In recent decades, an increase in late winter and early spring temperatures has been observed, potentially accelerating bud break, cambial activation and their potential coordination. Intracrown temperature heterogeneities could lead to asymmetric tree shapes unless there is a compensatory mechanism at the crown level. An original warming experiment was conducted on young Juglans regia trees in a greenhouse. From February to August, the average temperature difference during the day between warmed and control parts was 4{degrees}C. The warming treatment advanced the date of budbreak significantly, by up to 14 days. Warming did not alter secondary growth resumption but increased growth rates, leading to higher xylem cell production (twice as many) and to an increase in radial increment (+80% compared to control). Meristems resumptions were asynchronous without coordination in response to temperature. Buds on warmed branches began to swell two weeks prior to cambial division, which was one week earlier than on control branches. A difference in carbon and water remobilisation at the end of bud ecodormancy was noted under warming. Overall, our results argue for a lack of compensatory mechanisms at the crown scale, which may lead to significant changes in tree architecture in response to intra-crown temperature heterogeneities. Highlight: When tree are submitted to asymmetrical warming, it leads to early budbreak and enhanced cambial activity for warmed branches

developmental biology↗

bioRxiv2023

NanoMOFs with Encapsulated Photosensitizer: Accumulation in Chlamydia trachomatis Inclusions and Antimicrobial Effects

Metal-organic framework nanoparticles (nanoMOFs) are a promising class of hybrid nanomaterials for biomedical applications. Some of them, including biodegradable porous iron carboxylates are proposed for encapsulation and delivery of antibiotics. Due to the high drug loading capacity and fast internalization kinetics nanoMOFs are more beneficial for the treatment of intracellular bacterial infections compared to free antibacterial drugs, which poorly accumulate inside the cells because of the inability to cross membrane barriers or have low intracellular retention. However, nanoparticle internalization does not ensure their accumulation in the cell compartment that shelters a pathogen. This study shows the availability of MIL-100(Fe) MOF nanoparticles to co-localize with Chlamydia trachomatis, an obligate intracellular bacterium, in the infected RAW264.7 macrophages. Furthermore, nanoMOFs loaded with photosensitizer methylene blue (MB) exhibit complete photodynamic inactivation of Chlamydia trachomatis growth. Simultaneous infection and treatment of RAW264.7 cells with empty nanoMOFs resulted in a 3-fold decrease in bacterial load that indicates an intrinsic anti-chlamydial effect of this iron-containing nanomaterial. Thus, our findings suggest the use of iron-based nanoMOFs as a promising drug delivery platform, which contributes to antibacterial effect, for the treatment of chlamydial infections.

biophysics↗