Molecular Pharmaceutics最新文献

Ensitrelvir is a nonpeptide 3CL protease inhibitor used for coronavirus disease 2019 treatment. Four crystalline forms of ensitrelvir, metastable (Form I), acetonate (Form II), stable (Form III), and hydrate (Form IV), have been analyzed as pharmaceutical crystals. Their rank order of solubility is Form I > IV > III. Form III is the stable crystal with a significantly lower solubility than that predicted from its log P value of 2.7. Here, single-crystal structural analysis revealed strong intermolecular interactions between the triazine (acidic) and triazole (basic) groups of Form III not Forms I and IV. Multicomponent crystals were also designed to improve the solubility by altering the intermolecular interactions in Form III. Slurry conversion with equal molar ratios of ensitrelvir and fumaric acid successfully induced the formation of a novel cocrystal (Form V). Fumaric acid inhibited the triazine-triazole interactions, and dissolution of Form V was approximately 8- and 13-fold higher than that of Form III in pH 1.2 and 6.8 media, respectively. Furthermore, Form V exhibited an approximately 16-fold higher flux value than that of Form III. Therefore, alterations in intermolecular interactions via cocrystallization significantly enhance the dissolution and permeation of ensitrelvir.

Trophoblast cell surface antigen 2 (Trop2), a transmembrane glycoprotein, plays a dual role in physiological and pathological processes. In healthy tissues, Trop2 facilitates development and orchestrates intracellular calcium signaling. However, its overexpression in numerous solid tumors shifts its function toward driving cell proliferation and metastasis, thus leading to a poor prognosis. The clinical relevance of Trop2 is underscored by its utility as both a biomarker for diagnostic imaging and a target for therapy. Notably, the U.S. Food and Drug Administration (FDA) has approved sacituzumab govitecan (SG), a novel Trop2-targeted agent, for treating triple-negative breast cancer (TNBC) and refractory urothelial cancer, highlighting the significance of Trop2 in clinical oncology. Molecular imaging, a powerful tool for visualizing and quantifying biological phenomena at the molecular and cellular levels, has emerged as a critical technique for studying Trop2. This approach encompasses various modalities, including optical imaging, positron emission tomography (PET), single photon emission computed tomography (SPECT), and targeted antibodies labeled with radioactive isotopes. Incorporating Trop2-targeted molecular imaging into clinical practice is vital for the early detection, prognostic assessment, and treatment planning of a broad spectrum of solid tumors. Our review captures the latest progress in Trop2-targeted molecular imaging, focusing on both diagnostic and therapeutic applications across diverse tumor types, including lung, breast, gastric, pancreatic, prostate, and cervical cancers, as well as salivary gland carcinomas. We critically evaluate the current state by examining the relevant applications, diagnostic accuracy, therapeutic efficacy, and inherent limitations. Finally, we analyze the challenges impeding widespread clinical application and offer insights into strategies for advancing the field, thereby guiding future research endeavors.

Effective intercellular communication is crucial for tissue repair and regeneration, with exosomes playing a key role in mediating these processes by transferring proteins, lipids, and nucleic acids between cells. This study explored the mechanisms underlying the uptake of exosomes derived from human dental pulp stem cells (hDPSCs), human umbilical vein endothelial cells (HUVECs), and human fibroblasts (HFBs). Our findings revealed that hDPSCs exhibited the greatest capacity for exosome uptake across all three cell types. Moreover, exosomes originating from hDPSCs were also taken up in the highest amounts by all three cell types. Proteomic analysis uncovered significant differences in protein expression among exosomes from these different cell types, particularly in proteins related to endocytosis. Clathrin-dependent endocytosis emerged as the primary pathway for exosome uptake in hDPSCs and HUVECs, while HFBs appeared to use a different mechanism. Additionally, proteins such as fibronectin and tetraspanins were found to be highly expressed in hDPSC-derived exosomes, suggesting their potential involvement in exosome-cell interactions. This study offers new insights into exosome uptake mechanisms and highlights the potential of exosomes in advancing tissue engineering and regenerative medicine.

CD93 is overexpressed in multiple solid tumor types, serving as a novel target for antiangiogenic therapy. The goal of this study was to develop a ⁶⁴Cu-based positron emission tomography (PET) tracer for noninvasive imaging of CD93 expression. Antimouse-CD93 mAb (mCD93) and the CD93 ligand IGFBP7 were conjugated to a bifunctional chelator, p-isothiocyanatobenzyl-1,4,7-triazacyclononane-1,4,7-triacetic acid (p-SCN-NOTA) and labeled with ⁶⁴Cu. To evaluate the pharmacokinetic properties and tumor-targeting efficacy of [⁶⁴Cu]Cu-NOTA-mCD93 and [⁶⁴Cu]Cu-NOTA-IGFBP7, PET imaging and biodistribution were performed on both 4T1 murine breast tumor-bearing mice and MDA-MB-231 human breast tumor-bearing mice. The tumor model HT1080-FAP, which does not overexpress CD93, was used as a negative control. Fluorescent immunostaining was conducted on different tissues to correlate radiotracer uptake with CD93 expression. ⁶⁴Cu-labeling was achieved with high yield and specific activity. Serial PET imaging revealed that the in vivo performance of [⁶⁴Cu]Cu-NOTA-IGFBP7 was superior to that of [⁶⁴Cu]Cu-NOTA-mCD93, and that the tracer [⁶⁴Cu]Cu-NOTA-IGFBP7 exhibited elevated tumor uptake values and excellent tumor retention in MDA-MB-231 mice, rather than in 4T1 murine mice. The MDA-MB-231 tumor uptake of [⁶⁴Cu]Cu-NOTA-IGFBP7 was 2.85 ± 0.15, 3.69 ± 0.60, 6.91 ± 0.88, and 6.35 ± 0.55%ID/g at 1, 4, 24, and 48 h p.i., respectively, which were significantly higher than that in the CD93-negative HT1080-FAP tumor (0.73 ± 0.15, 0.97 ± 0.31, 1.00 ± 0.07, and 1.02 ± 0.11%ID/g, respectively). The significant difference between positive and negative tumors indicated [⁶⁴Cu]Cu-NOTA-IGFBP7 was specifically binding to CD93. Biodistribution data as measured by gamma counting were consistent with the PET analysis. Ex vivo histology further confirmed the high CD93 expression on MDA-MB-231 tumor tissues. Herein, we prepared two novel radiotracers, [⁶⁴Cu]Cu-NOTA-mCD93 and [⁶⁴Cu]Cu-NOTA-IGFBP7, for the first immune-PET imaging of CD93 expression. Our results suggest that [⁶⁴Cu]Cu-NOTA-IGFBP7 is a more potential radiotracer for visualizing angiogenesis due to its sensitive, persistent, and CD93-specific characteristics.

Plant viruses are naturally occurring nanoparticles and adjuvants that interact with the mammalian immune system. This property can be harnessed in vaccines and immunotherapy. We have previously demonstrated that intratumoral immunotherapy with cowpea mosaic virus (CPMV) stimulates systemic and durable antitumor immunity in mouse tumor models and canine cancer patients. Here we compared the antitumor efficacy of CPMV with potato virus X (PVX) using a mouse model B-cell lymphoma (A20 and BALB/c mice). Despite their diverse morphologies and physiochemical properties, both plant viruses elicited systemic and long-lasting antitumor immune memory, preventing the recurrence of A20 lymphoma in rechallenge experiments. Data indicate differences in the underlying mechanism: CPMV persists longer in the tumor microenvironment (TME) compared to PVX; CPMV is a potent and multivalent toll-like receptor (TLR) agonist (activating TLRs 2, 4 and 7) while PVX may only weakly engage with TLR7. While CPMV and PVX recruit myeloid cells (neutrophils)─CPMV also recruits macrophages. Data further indicate that antiviral T cells may play a role in antitumor efficacy in the case of CPMV immunotherapy, however this may not be the case for PVX. Regardless of the mechanism of action, both CPMV and PVX elicited a durable antitumor response against a B-cell lymphoma tumor model and thus are intratumoral immunotherapy candidates for clinical development.

Alcohol-induced dose dumping (AIDD) remains a serious challenge in the controlled delivery of high potency drugs, such as opioids, which requires extensive investigation and innovative solutions. Current technologies rely on ethanol-insoluble excipients, such as guar gum and sodium alginate, to counteract the increased solubility of hydrophobic polymeric excipients in ethanol. However, these excipients pose several shortcomings, such as high viscosity of coating dispersion, high solution temperature, rapid gelation, and heterogeneity of resulted film. In this work, we explored the application of a cross-linked terpolymer nanoparticle (TPN) as an alcohol-resistant excipient in a water-insoluble controlled release film of ethylcellulose (EC) for the prevention of AIDD. Herein, we optimized the composition of TPN using a central composite design (CCD) to minimize swelling and weight loss of TPN-EC film in the presence of 20% ethanol. The optimized TPN showed a negligible effect on the viscosity of the coating dispersion, while guar gum increased the viscosity by 76-fold. Permeability studies in a pH 1.2 media containing 0% or 40% v/v ethanol revealed that cationic drugs (propranolol HCl, diltiazem HCl, and naloxone HCl (an opioid receptor-binding model drug)) exhibited significantly lower permeability ratios (P_40%/P_0%) than un-ionized drugs (theophylline and salicylic acid). FTIR analysis indicated an increase in ionic hydrogen bonding between TPN and the cationic drug in the presence of ethanol. These results suggest that drug-polymer-solvent interactions play an important role in alcohol-independent drug permeability through the TPN-EC film. By leveraging the drug permeability altering capability of the TPN-EC system, the release of cationic drugs in hydroethanolic media appeared to be suppressed, suggesting a promising new mechanism of alcohol resistance.

The success of mRNA-LNP-based COVID-19 vaccines opens a new era for mRNA-LNP-based therapy. This breakthrough is expected to catalyze the development of more mRNA-LNP-based medicines, not only for preventive vaccines but also for therapeutic purposes. Despite the promising outlook, there are fundamental challenges impeding the progress and widespread application of mRNA-LNP formulations. One of the significant challenges is their thermal instability, requiring these products to be stored at ultralow temperatures for long-term stability. The specific requirements present significant challenges for the storage, transportation, and distribution of mRNA-LNP formulations. To effectively prepare for future infectious disease outbreaks and broaden the application of mRNA-LNP-based therapies for other illnesses, improving the thermostability of mRNA-LNP formulations is critical. In this review, we discuss the potential factors contributing to the thermal instability of mRNA-LNP formulations and examine the roles of key components such as ionizable lipids, cholesterol, pH, buffers, and stabilizing agents like sugars in maintaining their thermal stability, with the goal of providing insights that can guide the future development of thermally stable mRNA-LNP formulations.

In head and neck squamous cell carcinoma (HNSCC), the mesenchymal epithelial transition (MET) receptor drives cancer growth, proliferation, and metastasis. MET is known to be overexpressed in HNSCC and, therefore, is an appealing therapeutic target. In this study, we evaluated MET expression in patients with HNSCC and investigated the potential imaging application of a novel MET-binding single-domain camelid antibody using positron emission tomography/computed tomography (PET/CT) in a preclinical MET-expressing HNSCC model. Multiplex immunostaining for MET protein performed on a tissue microarray from 203 patients with HNSCC found 86% of patients to have MET expression, with 14% having high expression and 53% having low MET expression. Using The Cancer Genome Atlas (TCGA) database, high MET RNA expression was associated with worse progression-free survival and overall survival in patients with HPV-negative HSNCC. Utilizing flow cytometry and immunofluorescence, our novel camelid antibody fused to a human IgG Fc chain (1E7-Fc) showed high binding affinity and specificity to high MET-expressing Detroit 562 cells but not to low MET-expressing HNSCC cells. The efficacy and biodistribution of [⁸⁹Zr]Zr-1E7-Fc as a PET imaging agent was then investigated in a MET-expressing head and neck xenograft model. [⁸⁹Zr]Zr-1E7-Fc rapidly localized and showed high tumor uptake in Detroit 562 xenografts (8.4% ID/g at 72 h postinjection), with rapid clearance from the circulatory system (2.7 tumor-to-blood radioactivity ratio at 72 h postinjection). Our preclinical data suggest that the camelid antibody 1E7-Fc could be a potential theranostic agent for HNSCC. Further investigations are warranted to confirm these findings in patients and to evaluate 1E7-Fc as an imaging agent and platform to deliver radionuclide or drug therapy to MET-driven cancers.

Liposomes, small bilayer phospholipid-containing vesicles, are frequently used to ensure slow drug release for a prolonged and improved therapeutic effect. Nevertheless, current findings on the membrane affinity and permeability of the anticancer agent 5-fluorouracil (5-FU) are confounding, which leads to a lack of a clear understanding of how lipid composition impacts the distribution of 5-FU within liposomal structures and its delivery. In the current work, we report a comprehensive coarse-grained molecular dynamics (CGMD) investigation on the influence of cholesterol (CHOL) and the cationic lipid 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) on the partitioning of 5-FU in 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) double-bilayer systems, as well as its in vitro release from liposomes with identical lipid compositions. Our results show that 5-FU tends to accumulate at the water-lipid interface, in the vicinity of polar headgroups, without partitioning in the hydrophobic tail region. At the same time, the presence of CHOL proportionally increases the distribution of this drug in the interbilayer aqueous space, decreasing the drug's affinity toward the membrane polar head region, while DOTAP has only a slight effect on drug distribution. Thus, it is expected that 5-FU will be released slower from CHOL-containing DPPC liposomes but not DOTAP-containing vesicles. However, in vitro release studies showed that the release kinetics of 5-FU from DPPC vesicles is not influenced by the presence of CHOL and that the incorporation of 10 mol % DOTAP leads to the best release profile for 5-FU, highlighting the complexity of nanocarrier drug release kinetics. We hypothesize that the initial rapid release seen in dialysis experiments is not related to drug membrane permeability but rather to 5-FU adsorbed on the outer surface of liposomes.