Drug-coated balloons (DCBs) are effective tools for cardiovascular interventions, ensuring uniform drug delivery to occluded arteries. This research investigates the potential of Pluronic P123 (P123), a micelle-forming polymer, to solubilize and release Everolimus (EVE) from DCBs. Furthermore, it seeks to understand how the ratio of P123 to EVE affects release rates and micelle formation under physiological conditions. We tested three P123 to EVE ratios: 90:10, 75:25, and 50:50. Microscopy revealed that increasing EVE proportions resulted in more uniform coatings. Fourier-transform infrared spectroscopy (FTIR) analysis confirmed the successful incorporation of EVE into the P123 matrix without altering its chemical properties. Differential scanning calorimetry (DSC) studies showed that EVE incorporation affected the crystalline structure of P123, leading to more uniform coatings. In vitro release studies showed that all formulations had <1% drug loss in the first minute (the tracking phase); furthermore, the 90:10 ratio exhibited optimal drug release in the following 3 min, corresponding to the deployment phase in DCB angioplasty. Analysis of micelle loading capacity (LC), encapsulation efficiency (EE), size, and structure indicated an increase in both LC and EE with higher EVE content and a corresponding enlargement in micelle size. Given these findings, the optimized formula provided a consistent coating on commercial balloons, highlighting the potential of using P123 for DCB drug coating and release.
In Gram-negative bacteria, resistance-nodulation-division-type efflux pumps, particularly AcrAB-TolC, play a critical role in mediating resistance to antimicrobial agents and toxic metabolites, contributing to multidrug resistance. Photorhabdus laumondii is an entomopathogenic bacterium that has garnered significant interest due to its production of bioactive specialized metabolites with anti-inflammatory, antimicrobial, and scavenger deterrents properties. In previous work, we demonstrated that AcrAB confers self-resistance to stilbenes in P. laumondii TT01. Here, we explore the pleiotropic effects of AcrAB in this bacterium. RNA sequencing of acrA compared to wild-type revealed growth-phase-specific gene regulation, with stationary-phase cultures showing significant downregulation of genes involved in stilbenes, fatty acid, and anthraquinone pigment biosynthesis, as well as genes related to cellular clumping and fimbrial pilin formation. Genes encoding putative LuxR regulators, type VI secretion systems, two-partner secretion systems, and contact dependent growth inhibition systems were upregulated in acrA . Additionally, exponential-phase cultures revealed reduced expression of genes related to motility in acrA . The observed transcriptional changes were consistent with phenotypic assays, demonstrating that the acrA mutant had altered bioluminescence and defective orange pigmentation due to disrupted anthraquinone production. These findings confirm the role of stilbenes as signaling molecules involved in gene expression, thereby shaping these phenotypes. Furthermore, we showed that AcrAB contributes to swarming and swimming motilities independently of stilbenes. Collectively, these results highlight that disrupting acrAB causes transcriptional and metabolic dysregulation in P. laumondii , likely by impeding the export of key signaling molecules such as stilbenes, which may serve as a ligand for global transcriptional regulators.
Objective: EAPB0503, lead compound of imiqualines, presented high antitumor activities but also a very low water solubility which was critical for further preclinical studies. To apply to EAPB0503, a robust and safe lipid formulation already used for poor soluble anticancer agents for injectable administration at a concentration higher than 1 mg/mL. Materials and Methods: Physicochemical properties of EAPB0503 were determined to consider an adapted formulation. In a second time, lipid nanocapsules (LNC) formulations based on the phase-inversion process were developed for EAPB0503 encapsulation. Then, EAPB0503 loaded-LNC were tested in vitro on different cell lines and compared to standard EAPB0503 solutions. Results: Optimized EAPB0503 LNC displayed an average size of 111.7 ± 0.9 nm and a low polydispersity index of 0.059 ± 0.002. The obtained loading efficiency was higher than 96% with a drug loading of 1.7 mg/mL. A stability study showed stability during 4 weeks stored at 25°C. In vitro results highlighted similar efficiencies between LNC and standard EAPB0503 solutions prepared in dimethyl sulfoxide. Conclusion: In view of results obtained for loading efficiency and drug loading, the use of a LNC formulation is very interesting to permit the solubilization of a lipophilic drug and to improve its bioavailability. Preliminary tested pharmaceutical formulation applied to EAPB0503 significantly improved its water solubility and will be soon considered for future preclinical in vivo studies.
Imiqualines (imidazoquinoxaline derivatives) are anticancer compounds with high cytotoxic activities on melanoma cell lines. The first generation of imiqualines, with two lead compounds (EAPB0203 and EAPB0503), shows remarkable in vitro (IC50 = 1 570 nM and IC50 = 200 nM, respectively, on the A375 melanoma cell line) and in vivo activity on melanoma xenografts. The second generation derivatives, EAPB02302 and EAPB02303, are more active, with IC50 = 60 nM and IC50 = 10 nM, respectively, on A375 melanoma cell line. The aim of this study was to optimize the bioavailability of imiqualine derivatives, without losing their intrinsic activity. For that, we achieved chemical modulation on the second generation of imiqualines by conjugating amino acids on position 4. A new series of twenty-five compounds was efficiently synthesized by using microwave assistance and tested for its activity on the A375 cell line. In the new series, compounds 11a, 9d and 11b show cytotoxic activities less than second generation compounds, but similar to that of the first generation ones (IC50 = 403 nM, IC50 = 128 nM and IC50 = 584 nM, respectively). The presence of an amino acid leads to significant enhancement of the water solubility for improved drugability.
Le projet concerne des molecules heterocycliques, de faible poids moleculaire, presentant des activites cytotoxiques comparables a celles des meilleurs anticancereux actuellement sur le marche. Ces molecules sont originales, protegees par un brevet international et un brevet de selection depose en decembre 2014. La synthese des premieres molecules leaders est maitrisee et l’exemplification de la diversite moleculaire est en cours. Les etudes menees pour definir leur profil d’activite permettent d’identifier des caracteristiques tout a fait originales. Le projet, en phase de developpement preclinique academique, a permis l’identification de composes leaders presentant des potentiels de developpement en tant qu’anticancereux. Le mecanisme exact des molecules developpees est encore en cours d’etude et permettra de definir s’il s’agit d’un mode d’action unique ou multiple. Plusieurs tetes de series ont pu etre identifiees avec visiblement des modes d’actions differents. En effet, les composes EAPB0203 et EAPB0503 montrent un effet dose a partir de 1 µM sur la polymerisation de la tubuline mais la molecule EAPB02303, la plus active sur la lignee A375 (CI50 = 10 nM, de dix fois a cent fois plus active que les deux precedentes), ne montre aucune fixation a la tubuline a la dose de 1µM suggerant un mecanisme d’action different et original. Le sujet de recherche presente concerne le developpement des etudes precliniques de ces molecules a visee anticancereuse. Le premier axe de travail a ete de mettre au point une formulation galenique de l'EAPB0503 sous forme de nanocapsules lipidiques. Afin d’optimiser la biodisponibilite des composes, sans perdre leur activite intrinseque, nous avons ensuite realise une modulation chimique sur la structure la plus active des Imiqualines : l’EAPB02303. Afin d’ameliorer la balance globale hydrophilie/lipophilie (HLB) des composes derives de l’EAPB02303, nous avons greffe un residu acide amine en position 4. Enfin, la mise au point d’une methode de dosage de l’EAPB02303 et l’EAPB02302 en milieu plasmatique en vue d’une etude pharmacocinetique a ete le dernier axe du travail de these.
