Molecular Pharmaceutics最新文献

Vaginal yeast infections, such as vulvovaginal candidiasis (VVC), affect nearly three out of four women worldwide. Reoccurrence is frequent and requires repeated treatments with oral, antifungal medications at high doses. Prolonged treatments contribute to development of resistant fungal strains and the risk of systemic adverse effects. Vaginal drug delivery can overcome several of the disadvantages associated with oral drug administration. However, current dosage forms, such as vaginal creams and gels, are rapidly expelled from the vaginal tract and require daily dosing to ensure therapeutic outcome, thus jeopardizing patient compliance. Therefore, we developed rapidly dissolving microneedle arrays with a microneedle height reduction by 50% within 5 min, for local, vaginal delivery of antifungal drugs. Clotrimazole, a poorly water-soluble antifungal agent, was formulated in lipid-based nanocarriers (LNCs) and incorporated in the tips of microneedles. The antifungal activity was then tested against the most common VVC fungal strains, C. albicans and C. glabrata, using an in vitro disk diffusion assay and an explant model from bovine vaginal tissue. LNC loaded microneedles showed consistent significant inhibition of Candida spp. in comparison to blank microneedles and LNCs alone, with an inhibition diameter of 20-30 mm in vitro and a reduction of 3-5-fold fungal colonies ex vivo. Notably, the LNC-loaded microneedles inhibited fungal growth at a 10-fold lower drug dose than a commercial clotrimazole cream. Finally, a device prototype was developed in the form of an intravaginal ring incorporating multiple microneedle arrays on its surface, delivering a total drug dose of 0.1 mg per ring with 600 μm microneedle height. Local vaginal drug delivery using such microneedle-based devices could enable more effective treatment strategies for VVC.

Corneal injuries are a leading cause of vision impairment, yet current therapies provide limited benefit due to poor ocular bioavailability and rapid drug clearance. To address this challenge, we developed a pH-sensitive in situ gel of p-coumaric acid (pCA) for sustained ocular delivery and enhanced wound healing. In vitro studies on SIRC cells identified 80 μg/mL pCA as a safe and effective concentration for supporting viability and migration. The optimized gel, formulated with Carbopol 940 and HPMC K100 M using central composite design, exhibited rapid gelation at ocular pH, pseudoplastic rheology, suitable zeta potential, and high entrapment efficiency (85.95%). FESEM confirmed pH-triggered sol-gel transition, while in vitro release demonstrated sustained delivery for 12 h (92.62% cumulative release). Safety was verified through RBC lysis, CAM, goat corneal histology, and rabbit eye irritation tests, all showing no adverse effects. In vivo evaluation in a rat corneal alkali burn model confirmed accelerated wound healing. This system offers a safe, biocompatible, and effective ocular therapy for corneal wounds.

Over time, RNA oligonucleotides have emerged as critical tools in the field of drug discovery, offering potential therapeutic strategies for various diseases that are considered undruggable by conventional methods. Small activating RNAs (saRNAs) are a distinct subset of artificially designed short RNA duplexes (dsRNAs) that function as regulatory molecules which mediate the upregulation of endogenous gene expression by targeting specific sequences within gene promoters, acting at both the transcriptional and epigenetic levels. This process, termed RNA activation, is a conserved mechanism observed across a broad spectrum of eukaryotes, from small invertebrates like nematodes to humans. Effective in vivo delivery of saRNAs is achieved using various delivery systems, including lipid nanoparticles, aptamers, dendrimers, and lipopolyplexes, enabling the guide strand to direct AGO2 to the nucleus and activate transcription. This represents a promising therapeutic strategy for cancer and other diseases. This paper reviews current literature on saRNA biology, focusing on its characteristics, mechanisms of action, challenges, and role in upregulating transcription, while exploring its therapeutic potential and future applications in disease treatment.

Fibroblast activation protein (FAP) is expressed in more than 90% of tumor-associated fibroblasts in epithelial cancers, providing an excellent target for nuclear medicine diagnostics and therapy. Given the high cost of PET-CT, developing SPECT probes targeting FAP is necessary. A novel FAP inhibitor derived from UAMC1110 was synthesized and conjugated to DOTA via PEG chains. This resulted in a series of inhibitors with good targeting specificity, tumor uptake, and pharmacokinetics. In this study, UAMC1110 derivatives were used as FAP-targeting pharmacophores; PEG chains of varying lengths were employed for pharmacokinetic modification, and HYNIC was used as a bifunctional chelator. The derivatives were labeled with ^99mTc using different coligand combinations to explore how PEG chain length and coligand composition affect the in vivo and in vitro properties of ^99mTc-labeled FAPI. Four UAMC1110 derivatives (P4, P6, P8, P12) with different PEG chain lengths were synthesized, and a series of hydrophilic ^99mTc complexes were prepared. Stability and specificity studies demonstrated that these complexes exhibited good in vitro and in vivo stability and FAP-targeting specificity. In micro-SPECT imaging, these tracers showed rapid tumor accumulation, with ^99mTc-TE-P12 and ^99mTc-TT-P12 showing promising tumor uptake, low nontarget organ uptake, and high T/NT ratios, indicating potential as SPECT probes.

Amorphous solid dispersions (ASDs) are one of the most effective formulation strategies for improving the release rate and bioavailability of poorly water-soluble drugs. However, the release rates of polyvinylpyrrolidone vinyl acetate (PVPVA) based ASDs typically decrease dramatically once a certain drug loading (DL) is exceeded. The purpose of this study was to evaluate the impact of dissolution medium pH on the release behavior of basic drug-PVPVA ASDs for ASDs with different DLs. Loratadine (LRD) and ritonavir (RTV) were used as model basic drugs. The surface area normalized release rates of drug and polymer from the ASD were measured in over a range of solution pH conditions from 1.6 to 7.5. The evolving phase morphology of the hydrated ASD compact surface was observed using confocal fluorescence microscopy. To provide insight into the gel layer pH, a pH indicator was added to the ASD and the gel layer color was observed following immersion in media of different pH values. Surface area normalized release rate measurements revealed that ASDs with low DLs, where release was controlled by the polymer, showed rapid and pH-independent release. However, ASDs with higher DLs exhibited pH-dependent release. From the confocal fluorescence microscopy imaging, formation of a drug-rich barrier layer at the gel layer-solution interface was observed for higher DL ASDs. Visual imaging of the gel layer suggested formation of a pH-gradient for LRD-PVPVA ASDs but not for RTV-PVPVA ASDs. In conclusion, for weakly basic drugs with highly pH-dependent solubility, the medium pH is expected to impact the release rate of higher DL ASDs where release is controlled by the drug-rich layer formed following hydration. In contrast, for low DL ASDs where the polymer controls the release, pH is anticipated to have less impact on release. This study contributes additional understanding of the release mechanisms of PVPVA-based ASDs.

The BRAF^V600E mutation is a well-established oncogenic driver, and several oral inhibitors have achieved clinical success. However, radiolabeled tracers for the non-invasive imaging of this mutation remain limited. N-(2-Chloro-3-((3,5-dimethyl-4-oxo-3,4-dihydroquinazolin-6-yl)oxy)-5-fluorophenyl)propane-1-sulfonamide (74) is a novel oral inhibitor targeting BRAF^V600E with high inhibitory potency. Here, we report the synthesis of its precursor and the radiosynthesis of its ¹⁸F-labeled version, [¹⁸F]LP-1 ([¹⁸F]74). The tracer exhibited nanomolar cellular binding affinity for BRAF^V600E-positive A375 melanoma cells (IC₅₀ = 31.6 nM) and demonstrated selective uptake in tumor models with distinct BRAF mutation status. Blocking studies with the BRAF^V600E-selective inhibitor vemurafenib further confirmed its specific binding. Our findings highlight the potential of [¹⁸F]LP-1 as a lead structure for the development of PET molecular tracers capable of detecting BRAF^V600E mutation status in vivo and support the development of next-generation radiotracers based on the scaffold.

Liver-specific delivery of mRNAs encoding key regulatory genes via lipid nanoparticles (LNPs) is promising to restore liver homeostasis and resume liver functions in inflammatory liver diseases. However, inflammation downregulates the global mRNA expression in general as a self-defensive mechanism, e.g., to block viral protein expression, which also reduces the efficiency of therapeutic mRNA delivered to hepatocytes. In addition, ionizable LNPs are immunogenic, which exacerbates inflammation. In this project, we applied a novel immune-modulating telodendrimer (TD) nanodrug (ND) to inhibit inflammation and improve specific mRNA delivery. We tested TD ND in both mouse and human immune cells, liver cell lines, and primary human hepatocytes (PHH) to inhibit endotoxin-induced inflammation. TD ND was able to inhibit both endogenous and LPS-induced inflammation in liver cells, which improved cell proliferation in culture and also significantly enhanced the efficiency of mRNA/LNP delivery both in vitro in human monocytes and PHH. Finally, we demonstrated that TD ND is superior to steroid drugs in inhibiting endotoxin-induced inflammation and sustaining liver function in mice, thereby rebooting the efficacy of liver-targeted LNP mRNA delivery and expression. These findings highlight the potential of TD ND as an effective adjuvant therapy to enhance mRNA delivery for inflammatory disease treatments.

Hydrogen bonds (H-bonds) can have a critical impact on the stability and drug release characteristics of amorphous solid dispersions (ASDs). Based on the structure of the ASD components, it remains however difficult to predict the strength and influence of these H-bond interactions on the phase behavior of the ASDs. Therefore, this study assessed the miscibility and H-bond interactions of diflunisal (DIF) and four structural analogues in ASDs with Eudragit S100 (ES100) as a model polymer that contains H-bond-donor as well as H-bond-acceptor groups. The highest possible drug loading in the ASDs was smaller for native DIF and the DIF methyl ester derivative (25 wt %) as compared to the methoxy DIF and dimethyl DIF derivatives (35 wt %). Solid-state NMR relaxometry was employed to evaluate the molecular miscibility of the ASD components. In addition, ¹³C-CPMAS ssNMR spectroscopy was performed on spray-dried ASDs to evaluate the H-bond interactions between the API and polymer. It was observed that the ES100 carboxyl group interacted as an H-bond donor with the C═O carbonyl group of the DIF derivatives, leading to homogeneous mixing for all ASDs. However, it was also shown that competition between intermolecular H-bonds and intramolecular H-bonds, present as stable six-membered rings, is possible. The competition limited the availability of the API acceptor C═O group and explains the lower maximum drug loadings for native DIF and the DIF methyl ester. A comparison was also made between these ES100-based ASDs and PVPVA-based ASDs studied in a previous study. It became clear that for ASDs with a polymer that only carries H-bond-acceptor groups (like PVPVA), the availability of API H-bond-donor groups is crucial for the formation of H-bonds between the drug and the polymer. Contrastingly, for ASDs formed with a polymer that carries both H-bond-donor and -acceptor groups (like ES100), it seems to be the availability of API H-bond-acceptor groups that is crucial for intermolecular H-bond formation and drug-polymer miscibility.

Breast cancer (BC) is a serious health threat to women worldwide and is on the steady rise in morbidity and mortality, of which estrogen receptor α (ERα)-positive cases account for nearly 70%. ERα is highly expressed in ERα-positive (ERα+) BC, and it is involved in tumorigenesis and metastasis, making it a compelling target for BC theranostics. Herein, we developed and evaluated an ERα-targeted fluorescent probe (IRDye800-4OHT) by conjugating ERα targeting ligand 4-hydroxytamoxifen with near-infrared fluorescence dye IRDye800CW for ERα+ BC detection via imaging ERα. The probe demonstrated a second near-infrared (NIR-II) imaging capability (λ_em = 950 nm), high binding affinity (RBA = 2.3) toward ERα, and excellent biocompatibility. In vitro cellular uptake further confirmed that IRDye800-4OHT could specifically target the ERα. Moreover, in vivo NIR-II imaging clearly revealed that IRDye800-4OHT enabled real-time imaging of ERα, specifically illuminated tumor tissue, and successfully guided breast tumor resection. Therefore, we postulate that IRDye800-4OHT can serve as a valuable tool for the precise diagnosis and surgical excision of ERα-positive tumors.

NMR crystallography, which is based on both diffraction- and solid-state NMR-based observables, can deliver a precise description of the crystal structure of powdered samples of pharmaceuticals. On the other hand, it is by no means a straightforward technique, not least because of the overcrowding of solid-state NMR spectra and difficulties in reliably assigning all resonances, even when advanced 2D techniques are applied. In this work, we showcase the advantages of using very high magnetic field spectrometers in NMR crystallography to solve the structural puzzles posed by four new binary forms of meloxicam (MLX), an anti-inflammatory drug. In particular, we revealed a hidden disorder in the scXRD-determined crystal structure of one of the polymorphic forms of MLX with pyrazole (POL). In this instance, we discovered, through the use of ¹⁵N solid-state NMR data, that there is an exchange between two possible tautomeric forms, and by calculating the weighted average of ¹⁵N shielding constants, we determined the occupancy of the disordered sites to be 70:30. For the next two binaries, with pyrazine (MLX:PNA) and imidazole in a 1:2 ratio (MLX:IMI 1:2), we solved their crystal structures from powder XRD data and determined the protonation state mainly through the use of quadrupolar product (P_Q) of ¹⁴N, derived from ¹H-¹⁴N T-HMQC experiments recorded at two different magnetic field strengths. The signal assignment was done with a set of ¹H-¹H DQ-SQ Back-to-Back, ¹H-¹³C and ¹H-¹⁵N HETCOR experiments. For MLX:PNA, we found a very unusual tautomer of MLX inside this crystal, the one which has not been found in any other MLX forms discovered so far. For MLX:IMI 1:2, we established it to be an ionic cocrystal. Finally, for the second MLX binary with imidazole in 1:1 ratio (MLX:IMI 1:1), we used solid-state NMR data to first unambiguously prove that this is a salt and that it comprises one of the two possible tautomers of the MLX anion. This enabled reliable crystal structure prediction calculations for this form, leading to its final crystal structure through Rietveld refinement against the experimental powder XRD pattern.