Semaglutide is a glucagon-like peptide-1 receptor agonist widely used for the treatment of type 2 diabetes and obesity. Despite its clinical efficacy, oral administration remains challenging because of its limited gastrointestinal stability, poor epithelial permeability, and low affinity for lipid-based delivery systems. In the present study, a combined hydrophobic ion pairing (HIP) and solid lipid nanoparticle (SLN) approach was explored to improve semaglutide incorporation and delivery-related properties. Semaglutide was complexed with the cationic lipid DOTAP at different molar ratios (1:0-1:18) and subsequently incorporated into cetyl palmitate-based SLNs produced by microfluidic mixing using a herringbone device. The resulting formulations were characterized in terms of particle size, ζ-potential, encapsulation efficiency, morphology, solid-state organization, colloidal stability, release behavior, mucus interaction, cytocompatibility, and epithelial permeability. Among the various formulations prepared, the one prepared with a molar ratio semaglutide: DOTAP of 1:18 and a peptide concentration of 10% (w/w) (F10) showed the best results, combining particle sizes of less than 300 nm with almost complete encapsulation efficiency and a highly positive ζ-potential. FTIR, DSC, TGA and SAXS analyses confirmed the correct formation of the complex and its incorporation into the lipid matrix. The F10 formulation demonstrated good stability under simulated gastrointestinal conditions and a sustained-release profile. The formulation also exhibited strong interactions with mucus, whilst retaining the ability to diffuse through the mucin network. Cytocompatibility studies demonstrated acceptable cell viability at relevant concentrations, whilst permeability experiments through Caco-2 monolayers revealed an approximately 6-fold increase in apparent permeability compared to free semaglutide. Therefore, these findings indicate that the combination of DOTAP-mediated hydrophobic ion pairing and microfluidic-assisted SLN production represents a potentially promising strategy for improving semaglutide encapsulation, gastrointestinal stability, and epithelial transport, while maintaining a favorable balance between mucus interaction and mucodiffusion.
I. Arduino, R. Iacobazzi, Alessia Pontrelli et al.· International journal of pha...· 0 citations
Metastatic melanoma remains a critical clinical challenge due to high transcriptional plasticity and the physical barriers of the tumor microenvironment that limit the efficacy of standard therapies. In this study, we present a microfluidic-engineered poly(lactic-co-glycolic acid) nanoparticle (PLGA-NPs) platform designed to maximize therapeutic efficacy through the precise co-encapsulation of synergistic drug combinations. These monodisperse nanocarriers exhibit rapid, dose-dependent internalization across diverse patient-derived models, independent of their mutational background. Mechanistically, we demonstrate that PLGA-NPs uptake is primarily mediated by dynamin-dependent endocytosis and macropinocytosis, followed by a dynamic intracellular trafficking route that reaches a steady-state distribution within recycling endosomes, thereby enabling prolonged intracellular cargo retention. In 3D patient-derived spheroids, these nanoparticles exploit active cell-to-cell transfer consistent with transcytosis-like mechanism to penetrate the poorly accessible central core, effectively bypassing tissue-level resistance and considerably enhancing drug efficacy. In vivo biodistribution in orthotopically transplanted patient-derived xenografts confirmed highly efficient tumor targeting, while a strategic dose-modulation approach successfully optimized the tumor-to-liver accumulation ratio. Therapeutically, twice-weekly intravenous administration of trametinib-loaded NPs achieved superior tumor regression and significantly prolonged overall survival compared to daily oral administration of the free drug. Furthermore, we developed a dual-drug delivery system co-loading trametinib, MEK inhibitor, and alisertib, Aurora A kinase inhibitor. This formulation was optimized to maintain a previously established synergistic ratio which effectively overcome acquired resistance to standard-of-care therapies and induce durable tumor regression. Collectively, these findings establish the PLGA-NPs platform as a robust, clinically relevant strategy to enhance the pharmacokinetic profile of treatments for metastatic and drug-resistant melanoma.
Giulia Lovati, Pietro Milesi, Paolo Fossati et al.· Journal of Controlled Releas...· 0 citations
