Molecular Pharmaceutics最新文献

Reactive oxygen species (ROS) are significantly elevated in tumor cells, providing an intrinsic trigger for selective drug activation and tumor-specific therapy. However, commonly used ROS-responsive linkers, such as thioketals and boronates, often suffer from limited sensitivity or poor physiological stability, and the development of new ROS-responsive motifs remains scarce. Herein, we develop a hydrazide-derived diazaborine (DAB) scaffold and establish it as a general ROS-responsive linker for small-molecule prodrugs, combining physiological stability with efficient ROS responsiveness. Based on this platform, we construct a DAB-derived ROS-responsive copper complex small-molecule prodrug, DDABD@Cu, for tumor-specific therapy. DDABD@Cu integrates a DAB-caged diethyldithiocarbamate (DTC) moiety with an inert copper donor, in which the DAB group effectively blocks the copper-chelating activity of DTC, enabling inert co-delivery of both components. Upon ROS activation, DTC is released to initiate copper transfer, generating cytotoxic Cu(DTC)₂ in situ to induce proteotoxic stress via ubiquitinated protein accumulation while concomitantly producing quinone methide (QM) to deplete glutathione (GSH) and amplify oxidative stress. This cascade improves antitumor efficacy against non-small cell lung cancer while limiting off-target toxicity. Overall, this work provides a feasible strategy for designing ROS-responsive and copper complex prodrugs.

The development of ¹³⁴Ce as both a positron-emitting surrogate for ²²⁵Ac and a therapeutic Auger and conversion-electron (ACE) emitter has accelerated rapidly in recent years, positioning it as one of the most versatile emerging radionuclides for targeted radiopharmaceuticals. Existing PET radionuclides used as imaging surrogates for ²²⁵Acincluding ⁶⁴Cu, ⁶⁸Ga, and ⁸⁹Zrsuffer from kinetic, chemical, and dosimetric mismatches that limit their ability to accurately predict the biodistribution of the long-lived alpha emitter and the in vivo redistribution of its radioactive daughters. Lanthanum-based radionuclides (¹³²La, ¹³³La) offer improved chemical compatibility but face production challenges, imaging limitations, and sparse in vivo validation. In contrast, the ¹³⁴Ce/¹³⁴La pair offers the dual advantage of being an f-block element with chemistry closely mirroring that of ²²⁵Ac and whose high positron branching ratio (63.6%) and long half-life (t_1/2 = 3.16 days) enable extended-time PET imaging, specifically with longer half-life macromolecules in vivo. Recent studies have demonstrated gigabecquerel (GBq) scale production of high-purity ¹³⁴Ce, robust chelation strategies, and strong matched-pair performance with ²²⁵Ac across small molecules, antibodies, and pretargeting systems. Moreover, the first therapeutic application of ¹³⁴Ce/¹³⁴La therapies with ACEs and positrons has shown potent, PSMA-specific tumor repression with minimal off-target toxicity, highlighting its promise as a dual-function theranostic radionuclide. Collectively, the growing body of work on ¹³⁴Ce establishes it as a compelling next-generation imaging surrogate for [²²⁵Ac]Ac-based radiopharmaceuticals and a potential therapeutic candidate through the utilization of its ACEs and positrons. In this review, we summarize the current progress in the development of [¹³⁴Ce]Ce-based radiopharmaceuticals, highlighting studies reported to date for both imaging and therapeutic applications, and discuss the opportunities and challenges that must be addressed to advance this matched radionuclide pair toward clinical translation.

The landscape of drug discovery has expanded beyond the traditional chemical space into the domain of large, flexible molecules, including beyond rule-of-five (bRo5) macrocyclic peptides (MCPs). Molecular chameleonicity, the capacity to dynamically adapt the conformation to the environment, balancing aqueous solubility and membrane permeability, has the potential to improve the oral bioavailability of these compounds. However, we lack experimental methods that quantify chameleonicity in a high-throughput manner. To address this need, we introduce DynlogP, a novel high-throughput, fully automated assay based on reverse-phase LC−MS that can quantify chameleonicity with minimal compound input. DynlogP measures calibrated lipophilicity under conditions promoting either solvent hydrogen bonding (log P₇₀) or intramolecular hydrogen bonding (log P₉₅), providing a quantitative measure of chameleonicity (Δlog P₉₅₋₇₀) that is validated with NMR and molecular dynamics simulations. We profiled hundreds of molecules with DynlogP and demonstrate that chameleonicity is a common feature of MCPs. Machine learning models trained with DynlogP data allow for the prospective prediction of chameleonicity. Adoption and further refinement of DynlogP have the potential to empower compound prioritization and the design of orally bioavailable MCP-based therapeutics.

Cancer anorexia−cachexia syndrome (CACS) is a prevalent and debilitating complication of malignancy, characterized by reduced food intake, loss of skeletal muscle mass, and severe metabolic dysfunction. Insulin resistance and impaired glucose tolerance are prominent features of CACS and contribute to worsened prognosis, yet treatment options that improve metabolic regulation without exacerbating anorexia are limited. Although GLP-1 receptor (GLP-1R) agonists effectively enhance glucose control, their centrally mediated anorectic and aversive effects limit their use in cancer patients. To address this limitation, we developed a peripherally restricted GLP-1R agonist by conjugating exendin-4 (Ex4) to dicyanocobinamide (Cbi), a vitamin B12-derived corrin ring with minimal blood−brain barrier penetration. Here, we evaluate Cbi-Ex4 in vitro and across healthy and tumor-bearing rodent models. Cbi-Ex4 retained GLP-1R agonism and improved glucose tolerance without inducing anorexia, weight loss, or malaise, in contrast to native Ex4. These findings support peripheralized GLP-1R agonism as a promising strategy to improve metabolic dysfunction in cancer without worsening malaise and cachexia.

Nanoparticle barcoding is a powerful approach to accelerate preclinical screening of nanotherapeutics by enabling rapid collection of high-volume data using fewer biological resources, with reduced experimental labor and fewer confounding variables across experiments. We previously introduced aryl halide-based tags (halocodes) as a barcoding technology with sensitive gas chromatography−mass spectrometry (GC−MS) detection, enabling nanoparticle tracking with minimal halocode incorporation and without measurably altering nanoparticle physicochemical properties. Building on this foundation, in this work, we developed a next generation of alkoxy-modified halocodes with tunable chemical properties that enhance encapsulation and stability within nanomaterials and extend the halocoding platform to lipid-based systems. By systematically varying halocode chemical structure and nanoparticle synthesis parameters, we established design rules governing halocode loading and retention in both polymeric nanoparticles and liposomes. We then leveraged next generation halocodes to perform a pooled in vitro screen of a mixed-core PLGA and liposomal-based nanoparticle library to identify nanoparticle core and surface chemistries with the highest affinity for ovarian cancer cells. Together, next generation halocodes provide a more modular and broadly compatible barcoding toolkit that simplifies pooled screening and supports quantitative evaluation of diverse nanocarrier libraries across biological settings.

Direct in vivo imaging of myelin would greatly benefit research on demyelinating diseases such as multiple sclerosis but remains technically challenging. This study evaluated whether the amyloid-β radiotracer [¹⁸F]Flutemetamol is suitable for PET/CT imaging of myelin in the murine cuprizone model of demyelination. Male C57BL/6 mice were fed 0.3% cuprizone for five weeks (n = 5) or control chow (n = 5) and subsequently underwent a 90 min dynamic [¹⁸F]Flutemetamol PET/CT scan with a retest scan two days later. PET data were analyzed using region-of-interest-based quantification with an image-derived input function; volume of distribution (V_T) was estimated by Logan graphical analysis, and percentage injected dose per milliliter (% ID/mL) was calculated as a simplified uptake measure. Demyelination was independently validated by MRI and histology. Cuprizone treatment induced significant body weight loss and robust region-specific demyelination of the corpus callosum, confirmed by reduced myelin marker expression, increased astroglial and microglial activation, and corresponding MRI changes. In contrast, in vivo [¹⁸F]Flutemetamol PET showed rapid radiotracer washout, low brain retention, and high variability. Estimated V_T values were very low and did not differ between control and cuprizone-treated mice. Similarly, % ID/mL failed to detect group differences in any analyzed brain region and showed high test−retest variability. Despite histologically confirmed demyelination and corresponding T2-weighted MRI signal alterations, [¹⁸F]Flutemetamol PET/CT did not provide sufficient sensitivity or quantitative robustness to detect myelin loss in vivo. This negative finding might reflect a combination of tracer-related and methodological limitations, including limited spatial resolution and uncertainties in quantitative modeling, and therefore does not allow a definitive conclusion regarding the intrinsic suitability of [¹⁸F]Flutemetamol for preclinical myelin imaging.

We report the first-in-human evaluation of [¹⁸F]BIBD-181, a novel SV2A tracer designed with a fluoropropyl side chain to enable mild, automated radiosynthesis. A fully automated cGMP-compliant production process was developed on a commercial synthesizer, yielding the tracer with >95% radiochemical purity and molar activity >130 GBq/μmol. In eight healthy volunteers, [¹⁸F]BIBD-181 demonstrated excellent safety, rapid brain penetration peaking at 15 s post-injection, and a regional uptake pattern consistent with known synaptic vesicle glycoprotein 2A (SV2A) distribution (pallidum SUV = 2.01 ± 0.57 at 30 min). The effective dose was 2.7 μSv/MBq, with predominant renal clearance and no detectable defluorination. In pilot epilepsy patients, [¹⁸F]BIBD-181 positron emission tomography (PET) results revealed focal SV2A reductions that were confined to the epileptogenic lesionsa sclerotic hippocampus in one patient and a focal cortical dysplasia (FCD) in anotherwhereas [¹⁸F]FDG showed either extensive ipsilateral temporal hypometabolism or concordant focal hypometabolism, suggesting that SV2A imaging may offer more precise lesion delineation, particularly when [¹⁸F]FDG abnormalities extend beyond the true epileptogenic zone. These findings establish [¹⁸F]BIBD-181 as a clinically practical SV2A PET tracer with favorable dosimetry, simplified production, and promising utility for epilepsy surgical planning, warranting further validation in larger cohorts.

B7−H3 is widely expressed in multiple solid tumors but shows minimal expression in normal tissues, making it an ideal target for molecular imaging; however, its systematic investigation remains limited. In this study, we utilized the clinically investigated B7−H3-targeted antibody−drug conjugate (ADC) HS-20093 to develop and evaluate a novel immuno-positron emission tomography (immuno-PET) tracer, [⁸⁹Zr]Zr-DFO-HS-20093, for accurate imaging of B7−H3 expression in lung cancer and triple-negative breast cancer models. [⁸⁹Zr]Zr-DFO-HS-20093 was synthesized with high radiochemical purity (98.2 ± 0.6%). Cellular uptake assays revealed significantly higher tracer uptake in A549 cells than in 4T1 cells at 1, 2, and 4 h (all P < 0.0001), which was markedly reduced by blocking with excess unlabeled antibody. Immunofluorescence revealed predominant membrane localization of B7−H3 in 4T1 cells, whereas A549 cells exhibited pronounced intracellular distribution, suggesting enhanced internalization. In tumor-bearing mice, [⁸⁹Zr]Zr-DFO-HS-20093 positron emission tomography (PET)/CT enabled clear tumor visualization, with peak uptake at 24 h post-injection in both A549 and 4T1 xenografts (9.63 ± 1.97 and 7.15 ± 3.14 μCi/mL, respectively), supporting its potential for tumor imaging. Ex vivo biodistribution data corroborated the PET findings, showing significantly higher tracer uptake in A549 tumors (5.01 ± 1.19 % ID/g) than in blocked tumors (2.89 ± 0.43 % ID/g) and 4T1 tumors (1.89 ± 0.47 % ID/g) (P = 0.034 and P = 0.003, respectively). Immunohistochemical analysis of A549 xenografts showed strong B7−H3 expression (3+), whereas 4T1 tumors exhibited lower expression levels (1−2+), further confirming that B7−H3 expression patterns were consistent with the imaging results. [⁸⁹Zr]Zr-DFO-HS-20093 enables sensitive immuno-PET imaging of B7−H3 and reveals tumor-type-dependent differences in B7−H3 expression and intracellular behavior.

Regulation of the tumor suppressor p53 is a promising approach for cancer treatment; however, a single regulatory method often shows limited efficacy. Here, we develop an affibody-drug conjugate nanoagent (ADCN) for the targeted codelivery of topoisomerase I inhibitor DX8591 and p53-MDM2 inhibitor PMI to upregulate p53 levels in cancer cells. The tripartite conjugate Z_EGFR:1907-PMI-DX8591 self-assembled into nanoparticles with an average diameter of 74.4 nm, resulting in improved pharmacokinetic profiles and enhanced tumor-targeting ability. After efficient EGFR-mediated cellular uptake, the Z_EGFR:1907-PMI-DX8591 ADCN released DX8591 and PMI intracellularly, leading to synergistic p53 activation by inducing p53 production and blocking its degradation. In EGFR-positive non-small cell lung tumor models, the ADCN showed excellent tumor accumulation and achieved 81.7% tumor growth inhibition, which was 1.5-fold and 1.2-fold higher than those of the Z_EGFR:1907-PMI and Z_EGFR:1907-DX8591 monotherapies, respectively. This affibody-based delivery system provides a promising strategy for synergistic cancer therapy.

Macropa has formed more stable complexes with ²²⁵Ac,although DOTA has been extensively used as a chelator for ²²⁵Ac. This study aimed to design and synthesize two novel ²²⁵Ac-labeled RGD peptides, [²²⁵Ac]Ac-Macropa-c(RGDyK) ([²²⁵Ac]1) and [²²⁵Ac]Ac-Macropa-[c(RGDyK)]₂ ([²²⁵Ac]2), and to evaluate theirpotential for targeted alpha therapy (TAT) of glioblastoma. Further,whether combination therapy with homoarginine (hArg), a modulatorof lysosomal function, could further improve therapeutic efficacywas investigated. In Colon-26 cells, [²²⁵Ac]2 demonstrated significantly higher cellular uptake and cytotoxicitythan [²²⁵Ac]1. In Colon-26 tumor-bearing mice,[²²⁵Ac]2 exhibited higher tumor accumulationand significant tumor growth inhibition. In GL261 glioblastoma cells,[²²⁵Ac]2 showed comparable cellular uptaketo that in Colon-26 cells, and combination with hArg in vitro improvedits cytotoxicity. However, no significant difference in therapeuticefficacy was observed between the hArg-treated and control groupsin the orthotopic GL261 glioblastoma mouse model. The results of thisstudy indicate the potential of ²²⁵Ac-labeled RGD peptidesincorporating Macropa as a chelator as promising agents for TAT. However,the further optimization of combination strategies and pharmacokineticsis required.