Biology subjects

Coll, J.-L.

Publications and source records attributed to Coll, J.-L..

4 recordsLinked to original sources

bioRxiv2025

Radiotherapy Enhancement by Gold Nanocluster-functionalized Nanoliposomes Using Polychromatic Orthovoltage X-ray Irradiation

Pancreatic ductal adenocarcinoma (PDAC) remains one of the most lethal cancers, as the most effective chemoradiation therapies achieve unsatisfactory outcomes while associated with high toxicity. Nanoliposomal drug delivery systems are widely used to improve chemotherapy safety, yet passive release of amphiphilic drugs may still associate with adverse toxicity. To address this, we previously developed nanoliposomes functionalized with hydrophobic gold nanoclusters, demonstrating radiocatalytic activity and enhanced chemoradiotherapy effects in 3D PDAC microtumors under synchrotron irradiation. In this study, gold nanocluster-functionalized nanoliposomes (AuLPs) were optimized and evaluated under 220 kVp orthovoltage X-ray irradiation, widely used in preclinical irradiation systems. AuLPs containing 0.2 mol% gold nanoclusters produced 1.5-fold more reactive oxygen species than unloaded liposomes. However, higher molar ratios were necessary to improve radiotherapy outcomes in 3D PDAC microtumor models following 4 and 8 Gy irradiation. Pharmacokinetics and biodistribution evaluations showed a modest increase in tumor gold content 24 hours post-injection in orthotopic PDAC models. Altogether, these results underscore the potential of gold-radiotherapy-responsive liposomes while highlighting critical formulation challenges, which must be resolved for full therapeutic potential.

bioengineering↗

bioRxiv2025

The delivery of nano-formulated drugs to solid tumours is selectively increased by co-application of the vascular disrupting agent CA4P

Improving the efficacy of existing cytotoxic chemotherapeutics requires increasing drug delivery to tumours while minimising systemic toxicity. Formulating these drugs as nanoparticles can reduce their exposure to healthy tissues, but broadly applicable strategies to enhance tumoral accumulation are lacking. Here, we show that co-administering small molecule vascular disrupting agents together with nanoparticle formulations (e.g. diagnostic reporters, or clinical drugs irinotecan and doxorubicin) increases their tumoral uptake by up to threefold, without raising systemic exposure. In a syngeneic mouse model of triple-negative breast cancer, this enhancement diminished when co-treatments were repeated, limiting its therapeutic benefit. However, since most solid tumour types are susceptible to vascular disrupting agents, this approach may be a broadly applicable strategy to improve the selectivity of drug delivery: with particular relevance for single dose use in diagnostic or research settings. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=101 SRC="FIGDIR/small/669501v1_ufig1.gif" ALT="Figure 1"> View larger version (36K): org.highwire.dtl.DTLVardef@a5b07corg.highwire.dtl.DTLVardef@1e5dcd2org.highwire.dtl.DTLVardef@49134org.highwire.dtl.DTLVardef@1d90aae_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗

bioRxiv2025

Self-Assembled siRNA-Gold Supraclusters Detected at the Single-Molecule Level in the NIR-II Window

Gold nanoclusters (AuNCs) possess unique photophysical properties that make them excellent candidates for advanced bioimaging and single-particle detection. In this work, we report the self-assembly of highly emissive, positively charged NIR-II AuNCs stabilized by cysteamine, directed by small interfering RNA (siRNA), which serves as both a structural and electrostatic modulator. The resulting supramolecular assemblies exhibit quasi-spherical morphologies around 100 nm in diameter, with outstanding colloidal stability, photostability, and enzymatic resistance. Their strong photoluminescence, extending up to 1400 nm, enables robust single- particle detection in solution. Spectroscopic and structural analyses--including fluorescence spectroscopy, small-angle X-ray scattering (SAXS), and single-particle tracking--highlight the pivotal role of siRNA in tuning the assembly process via charge balance and concentration- dependent interactions. Beyond providing insights into the structural and photophysical behavior of nucleic acid-guided AuNC assemblies, these results underscore their promise as multifunctional nanoplatforms for integrated imaging and gene-silencing therapies in biophotonic and theranostic applications.

bioengineering↗

bioRxiv2020

Two antagonistic microtubule targeting drugs act synergistically to kill cancer cells

Paclitaxel is a microtubule stabilizing agent and a successful drug for cancer chemotherapy inducing, however, adverse effects. To reduce the effective dose of paclitaxel, we searched for drugs which could potentiate its therapeutic effect. We have screened a chemical library and selected Carba1, a carbazolone, which exerts synergistic cytotoxic effects on tumor cells grown in vitro, when co-administrated with a low dose of paclitaxel. Carba1 targets the colchicine binding-site of tubulin and is a microtubule-destabilizing agent. The Carba1-induced modulation of microtubule dynamics increases the accumulation of fluorescent paclitaxel inside microtubules, providing a mechanistic explanation of the observed synergy between Carba1 and paclitaxel. The synergistic effect of Carba1 with paclitaxel on tumor cell viability was also observed in vivo in xenografted mice. Thus, a new mechanism favoring paclitaxel accumulation in microtubules can be transposed to in vivo mouse cancer treatments, paving the way for new therapeutic strategies combining low doses of microtubule targeting agents with opposite mechanisms of action.

cancer biology↗