Preclinical Evaluation Research Articles

Radiosynthesis and Preclinical Evaluation of m-[18F]FET and [18F]FET-OMe as Novel [18F]FET Analogs for Brain Tumor Imaging.

O-([18F]Fluoroethyl)-l-tyrosine ([18F]FET) is actively transported into the brain and cancer cells by LAT1 and possibly other amino acid transporters, which enables brain tumor imaging by positron emission tomography (PET). However, tumor delivery of this probe in the presence of competing amino acids may be limited by a relatively low affinity for LAT1. The aim of the present work was to evaluate the meta-substituted [18F]FET analog m-[18F]FET and the methyl ester [18F]FET-OMe, which were designed to improve tumor delivery by altering the physicochemical, pharmacokinetic, and/or transport properties. Both tracers could be prepared with good radiochemical yields of 41-56% within 66-90 min. Preclinical evaluation with [18F]FET as a reference tracer demonstrated reduced in vitro uptake of [18F]FET-OMe by U87 glioblastoma cells and no advantage for in vivo tumor imaging. In contrast, m-[18F]FET showed significantly improved in vitro uptake and accelerated in vivo tumor accumulation in an orthotopic glioblastoma model. As such, our work identifies m-[18F]FET as a promising alternative to [18F]FET for brain tumor imaging that deserves further evaluation with regard to its transport properties and in vivo biodistribution.

Synthesis and Preclinical Evaluation of Novel 68Ga-DOTA-RBB as Potential PET Radiotracer for Imaging CDK4/6 in Tumors

Synthesis and Preclinical Evaluation of Novel ⁶⁸Ga-DOTA-RBB as Potential PET Radiotracer for Imaging CDK4/6 in Tumors

Twenty-eight days of repeated dose sub-acute toxicological evaluation of polyherbal Ayurvedic medicine BPGrit in Sprague-Dawley rats.

A pre-clinical toxicological evaluation of herbal medicines is necessary to identify any underlying health-associated side effects, if any. BPGrit is an Ayurveda-based medicine prescribed for treating hypertensive conditions. High-performance liquid chromatography-based analysis revealed the presence of gallic acid, ellagic acid, coumarin, cinnamic acid, guggulsterone E, and guggulsterone Z in BPGrit. For sub-acute toxicity analysis of BPGrit, male and female Sprague-Dawley rats were given repeated oral gavage at 100, 300, and 1000 mg/kg body weight/day dosages for 28 days, followed by a 14-day recovery phase. No incidences of mortality, morbidity, or abnormal clinical signs were observed in BPGrit-treated rats throughout the study period. Also, the body weight and food consumption habits of the experimental animals did not change during the study duration. Hematological, biochemical, and histopathological analysis did not indicate any abnormal changes occurring in the BPGrit-treated rats up to the highest tested dose of 1000 mg/kg body weight/day. Finally, the study established the "no-observed-adverse-effect level" for BPGrit at >1000 mg/kg body weight/day in Sprague-Dawley rats.

Radiochemical synthesis and pre-clinical evaluation of [68Ga]Ga-FAPI-4 formulated using in-house developed FAPI-4 kit

Radiochemical synthesis and pre-clinical evaluation of [68Ga]Ga-FAPI-4 formulated using in-house developed FAPI-4 kit

Biofunctionalization of dental abutments by a zinc/chitosan/gelatin coating to optimize fibroblast behavior and antibacterial properties.

Tightly sealed peri-implant gingival tissue provides a barrier against oral bacterial invasion, protecting the alveolar bone and maintaining long-term implant survival. To investigate if zinc can enhance the integration between peri-implant gingival tissue and abutment surface, we herein present novel zinc/chitosan/gelatin (Zn/CS/Gel) coatings prepared using the electrophoretic deposition (EPD) technique. The effect of these coatings on human gingival fibroblasts (hGFs) was investigated by culturing these cells on top of the EPD coatings. Surface characterization demonstrated that Zn2+ were released in a sustained and pH-responsive manner. The preclinical cell culture evaluation of these coatings indicated that the zinc-containing coatings enhanced cell migration, adhesion and collagen secretion of hGFs. Moreover, the zinc-containing coatings exhibited antibacterial efficacy by inhibiting the growth of Porphyromonas gingivalis and reducing attachment of Staphylococcus aureus. Notably, zinc-free CS/Gel coatings prevented attachment of P. gingivalis as well. The coatings were also shown to be cytocompatible with epithelial cells and osteoblasts, which are other relevant cell types which surround dental implants after clinical placement. Based on our findings, it can be concluded that Zn-containing coatings hold promise to enhance the adhesion of gingival tissue to the implant surface, which may potentially contribute to the formation of a robust peri-implant soft sealing counteracting bacterial invasion.

Porcine Model of Cerebral Ischemic Stroke Utilizing Intracortical Recordings for the Continuous Monitoring of the Ischemic Area

Purpose: Our aim was to use intracortical recording to enable the tracking of ischemic infarct development over the first few critical hours of ischemia with a high time resolution in pigs. We employed electrophysiological measurements to obtain quick feedback on neural function, which might be useful for screening, e.g., for the optimal dosage and timing of agents prior to further pre-clinical evaluation. Methods: Micro-electrode arrays containing 16 (animal 1) or 32 electrodes (animal 2–7) were implanted in the primary somatosensory cortex of seven female pigs, and continuous electrical stimulation was applied at 0.2 Hz to a cuff electrode implanted on the ulnar nerve. Ischemic stroke was induced after 30 min of baseline recording by injection of endothelin-1 onto the cortex adjacent to the micro-electrode array. Evoked responses were extracted over a moving window of 180 s and averaged across channels as a measure of cortical excitability. Results: Across the animals, the cortical excitability was significantly reduced in all seven 30 min segments following endothelin-1 injection, as compared to the 30 min preceding this intervention. This difference was not explained by changes in the anesthesia, ventilation, end-tidal CO2, mean blood pressure, heart rate, blood oxygenation, or core temperature, which all remained stable throughout the experiment. Conclusions: The animal model may assist in maturing neuroprotective approaches by testing them in an accessible model of resemblance to human neural and cardiovascular physiology and body size. This would constitute an intermediate step for translating positive results from rodent studies into human application, by more efficiently enabling effective optimization prior to chronic pre-clinical studies in large animals.

Structural geometry, electronic properties and pre-clinical evaluation of antibacterial compounds from lichen-associated Streptomyces mobaraensis DRM1 and Nocardiopsis synnemataformans DRM2

Antibacterial compounds Phenol, 2,4-bis(1,1-dimethylethyl) and Lupeol obtained from lichen-associated Streptomyces mobaraensis DRM1 and Nocardiopsis synnemataformans DRM2 respectively. The geometry, electronic properties and binding affinities of antibacterial compound Phenol, 2,4-bis(1,1-dimethylethyl) and Lupeol was determined. The in silico molecular mechanics of bacterial growth inhibition by Phenol, 2,4-bis(1,1-dimethylethyl) and Lupeol was established in Pseudomonas aeroginosa and Salmonella typhi by molecular docking, molecular simulation approach. The bacterial growth is inhibited by inactivating the vital enzyme PqsA and actin in bacterial system of Pseudomonas and Salmonella. The antibacterial compound produced by lichen associated actinobiont are adhere to Lipinski rule 5 and established criteria for drug likeness with the acceptable ADME properties and expand our understanding of their pharmacological approach. Further it also revels the adaptation and survival lichen in adverse climatic condition through the antimicrobials in lichen-associated actinobiont.

Preclinical Evaluation of JAB-2485, a Potent AURKA Inhibitor with High Selectivity and Favorable Pharmacokinetic Properties

Preclinical Evaluation of JAB-2485, a Potent AURKA Inhibitor with High Selectivity and Favorable Pharmacokinetic Properties

Pharmacokinetic and Environmental Risk Assessment of Prime-2-CoV, a Non-Replicating Orf Virus-Based Vaccine against SARS-CoV-2

Viral vector vaccines represent a substantial advancement in immunization technology, offering numerous benefits over traditional vaccine modalities. The Orf virus (ORFV) strain D1701-VrV is a particularly promising candidate for vaccine development due to its distinctive attributes, such as a good safety profile, the ability to elicit both humoral and cellular immunity, and its favorable genetic and thermal stability. Despite ORFV’s theoretical safety advantages, such as its narrow host range and limited systemic spread post-inoculation, a critical gap persists between these theoretical benefits and the empirical evidence regarding its in vivo safety profile. This discrepancy underscores the need for comprehensive preclinical validations to bridge this knowledge gap, especially considering ORFV’s use in humans. Our research introduces Prime-2-CoV, an innovative ORFV-based vaccine candidate against COVID-19, designed to elicit a robust immune response by expressing SARS-CoV-2 Nucleocapsid and Spike proteins. Currently under clinical trials, Prime-2-CoV marks the inaugural application of ORFV in human subjects. Addressing the aforementioned safety concerns, our extensive preclinical evaluation, including an environmental risk assessment (ERA) and detailed pharmacokinetic studies in rats and immunocompromised NOG mice, demonstrates Prime-2-CoV’s favorable pharmacokinetic profile, negligible environmental impact, and minimal ERA risks. These findings not only affirm the vaccine’s safety and efficacy but also pioneer the use of ORFV-based therapeutics, highlighting its potential for wider therapeutic applications.

Feasible mechanisms and therapeutic potential of food probiotics to mitigate diabetes‐associated cancers: A comprehensive review and in silico validation

AbstractPeople with diabetes mellitus (DM) and hyperglycemia are linked with cancer risk. Diabetes and cancer have been corroborated by high morbidity and mortality rates. Studies revealed that elevated levels of insulin secretions trigger insulin‐like growth factor 1 (IGF‐1) production. Moreover, IGF‐1 is a key regulator involved in promoting cancer cell progression and is linked with DM. Cancer drug resistance and ototoxic effects can adversely affect the health and lifespan of an individual. However, naturally derived bioactive compounds are gaining attention for their nontoxic properties and specific behavior. Likewise, probiotics have also been regarded as safe and successful alternatives to treat DM‐linked cancers. The present review aims to highlight the therapeutic potential and feasible functions of probiotics to mitigate or inhibit DM‐associated cancers. Meanwhile, the intracellular signaling cascades involved in promoting DM‐linked cancer are enumerated for future prospective research. However, metabolomics interactions and protein–protein interactions are to be discussed for deeper insights into affirmative principles in diabetic‐linked cancers. Drug discovery and innovative preclinical evaluation need further adjuvant and immune‐enhancement therapies. Furthermore, the results of the in silico assessment could provide scientific excellence of IGF‐1 in diabetes and cancer. Overall, this review summarizes the mechanistic insights and therapeutic targets for diabetes‐associated cancer.

Synthesis and Preclinical Evaluation of Urea-Based Prostate-Specific Membrane Antigen-Targeted Conjugates Labeled with 177Lu

Synthesis and Preclinical Evaluation of Urea-Based Prostate-Specific Membrane Antigen-Targeted Conjugates Labeled with ¹⁷⁷Lu

Pre-Clinical Evaluation of Left Atrial Appendage Closure Device in Mitigating Risk of Stroke in Patients with Atrial Fibrillation: Promising Results from Animal Trials with Future Prospects

Abstract: Atrial fibrillation (AF) is the most common clinical disorder of cardiac arrhythmia in geriatrics, characterized by the presence of disorganized and irregular electrical activity in atrial myocardium, which leads to worsening of the heart's systolic function. Left atrial appendage (LAA) is a tubular, tiny aperture construction, connecting the left atrium (LA) with separate structure from LA with distinctive mechanical, hormonal, and structural properties. AF and Mitral valve regurgitation disease elevate the chances of thrombus formation in LAA, these ultimately turns into stroke. Obstructing thrombus by using a Left Atrial Appendage Closure Device (LAAC) and preventing it from entering internal carotid arteries, the risk of LAA thrombosis can be decreased. This article serves as a comprehensive compilation detailing the successful development and implantation of Left Atrial Appendage Closure (LAAC) Device with its novel design and geometry in two pigs (pre-clinical evaluation), showcasing promising results that have future implications for addressing cardiovascular disease in humans.

Nanostructured Lipid Carriers for oral treatment of leishmaniasis: Design and preclinical evaluation

Pentavalent antimonials are the primary treatment for leishmaniasis due to their proven efficacy and cost-effectiveness. However, they present poor oral absorption, parenteral administration, and serious adverse effects due to prolonged use. Nanostructured Lipid Carriers (NLC) offer a promising solution, providing prolonged release, enhanced intestinal permeability, and oral bioavailability. This study aimed to address these issues by developing Nanostructured Lipid Carrier loaded with meglumine antimoniate (NLC-MA) for oral leishmaniasis treatment. We used design of experiments (DoE) for optimization. The chosen NLC-MA was characterized assessing size, polydispersity index (PdI), zeta potential (ZP), entrapment efficiency (EE), pH, and by analytical techniques such as DSC, FTIR, XRD, and TEM. Stability under simulated gastrointestinal conditions, in vitro release kinetics, cytotoxicity in RAW 264.7 macrophages, and leishmanicidal activity were assessed. NLC-MA presented 41.13 nm, PdI 0.227, ZP −27.9 mV, EE of 62.43%, and pH 5.23. Characterization techniques confirmed drug incorporation and nanoparticles with reduced crystallinity. TEM images showed spherical morphology. NLC remained stable in gastrointestinal pH and under refrigeration storage, while lyophilized formulations retained their initial properties. MA release from NLC followed the Peppas-Sahlin model, an anomalous transport mechanism. Importantly, MA showed no cytotoxicity in macrophages, but the NLCs exhibited cytotoxicity beyond 50 µg/mL. NLC-MA displayed improved efficacy against Leishmania infantum. Overall, these results highlight the potential of utilizing a lipid nanocarrier incorporating meglumine antimoniate as an innovative drug delivery platform for oral treatment against leishmaniasis.

Formulation characterization of lecithin organogel as topical drug delivery system for psoriasis: In-vitro permeation and preclinical evaluation.

Psoriasis is a chronic inflammatory and proliferative skin disease that causes pathological skin changes and has a substantial impact on the quality of patient life. Apremilast was approved by the US Food and Drug Administration as an oral medication for psoriasis and is beneficial in mild to moderate conditions for chronic usage. However, 5%-7% of withdrawals were reported due to severe side effects. To address the issue, a localized drug delivery strategy via the topical route may be a viable approach. However, poor physicochemical properties make it vulnerable to passing through the skin, requiring a specialized drug delivery system to demonstrate its full potential via a topical route like lecithin organogel. The formulation was optimized by screening the suitable lecithin type and non-polar solvents based on the gel formation ability of lecithin and the solubility of apremilast in the solvent. The pseudo-ternary diagram was used to optimize the water content required to form the gel. The optimized gel was found to be shear thinning characterized for rheological parameters, in-vitro diffusion studies, and in-vitro skin distribution studies. Preclinical studies in Imiquimod-induced mice showed a better reduction in severity index, cytokine levels, and epidermal hyperplasia from the lecithin organogel group compared to the apremilast oral administration and marketed standard topical gel group. Based on these results, lecithin organogel can be considered a promising approach to deliver molecules like apremilast by topical route in psoriatic-like conditions.

Preclinical evaluation of novel synthesised nanoparticles based on tyrosine poly(ester amide) for improved targeted pulmonary delivery

Fixed dose combinations (FDCs) incorporating two or three medicines in a single inhaler have been created to enhance patient compliance and hence clinical outcomes. However, the development of dry powder inhalers (DPIs), particularly for FDCs, faces challenges pertinent to formulation uniformity and reproducibility. Therefore, this project aimed to employ nanotechnology to develop a FDC of DPIs for market-leading medicines—fluticasone propionate (FP) and salmeterol xinafoate (SAL)—for asthma management. Nanoaggregates were prepared using a novel biocompatible and biodegradable poly(ester amide) based on the amino acid tyrosine, utilising a one-step interfacial polymerisation process. The produced tyrosine poly (ester amide) drug-loaded nanoparticles were evaluated for content uniformity, PSA, FTIR, TEM, DSC, XRD and aerodynamic performance (in vitro and in vivo). The optimised formulation demonstrated high entrapment efficiency– > 90%. The aerodynamic performance in terms of the emitted dose, fine particle fraction and respirable dose was superior to the carrier-based marketed product. In-vivo studies showed that FP (above the marketed formulation) and SAL reached the lungs of mice in a reproducible manner. These results highlight the superiority of novel FDC FP/SAL nanoparticles prepared via a one-step process, which can be used as a cost-effective and efficient method to alleviate the burden of asthma.

EGCG Disrupts the LIN28B/Let-7 Interaction and Reduces Neuroblastoma Aggressiveness.

Neuroblastoma (NB) is the most commonly diagnosed extracranial solid tumor in children, accounting for 15% of all childhood cancer deaths. Although the 5-year survival rate of patients with a high-risk disease has increased in recent decades, NB remains a challenge in pediatric oncology, and the identification of novel potential therapeutic targets and agents is an urgent clinical need. The RNA-binding protein LIN28B has been identified as an oncogene in NB and is associated with a poor prognosis. Given that LIN28B acts by negatively regulating the biogenesis of the tumor suppressor let-7 miRNAs, we reasoned that selective interference with the LIN28B/let-7 miRNA interaction would increase let-7 miRNA levels, ultimately leading to reduced NB aggressiveness. Here, we selected (-)-epigallocatechin 3-gallate (EGCG) out of 4959 molecules screened as the molecule with the best inhibitory activity on LIN28B/let-7 miRNA interaction and showed that treatment with PLC/PLGA-PEG nanoparticles containing EGCG (EGCG-NPs) led to an increase in mature let-7 miRNAs and a consequent inhibition of NB cell growth. In addition, EGCG-NP pretreatment reduced the tumorigenic potential of NB cells in vivo. These experiments suggest that the LIN28B/let-7 miRNA axis is a good therapeutic target in NB and that EGCG, which can interfere with this interaction, deserves further preclinical evaluation.

Nanocarrier-based Drug Delivery of Brinzolamide for Ocular Diseases: A Mini-Review

Abstract: Brinzolamide (BRZ) represents a significant advancement in glaucoma treatment as a topically active carbonic anhydrase inhibitor (CAI). It exhibits selectivity and potent inhibitory activity for carbonic anhydrase type II isozyme (CA-II), which is crucial in aqueous humor secretion. With excellent ocular bioavailability and a formulation optimized for physiologic pH, brinzolamide effectively lowers intraocular pressure by inhibiting CA-II in ciliary processes. Its superior ocular comfort profile enhances patient compliance. Preclinical evaluations confirm its specific CA inhibition without notable side effects, and its low systemic absorption minimizes systemic CA inhibition-related issues. BRZ's prolonged tissue half-life in the eye ensures sustained IOP reduction, supported by clinical trials demonstrating comparable efficacy with reduced dosing frequency. Challenges in ocular disease treatment arise from physiological, anatomical, and dynamic barriers hindering effective drug delivery to the eye. Nanocarriers, such as micelles, nanoparticles, liposomes, niosomes, and dendrimers, offer promising solutions by improving permeation, targeting specific sites, and overcoming the limitations of conventional forms. This review explores diverse nanomedicines, detailing their applications, advantages, and disadvantages in ophthalmic drug delivery. It also includes recent research findings for a comprehensive overview of the current landscape.

Pre-clinical evaluation of effectiveness of infusion solutions with different osmolarity during acute blood loss in experiments on rats

The aim of the research was to experimentally evaluate the effectiveness of infusion solutions with different osmolarity during acute blood loss in experiments on rats. Material and methods. Experiments approved by the local Ethics Committee, have been done on 30 male rats line Vistar (320 ± 35 g). Design of the research included anesthesia, simulation of acute blood loss to 50 % of circulating blood volume, its replenishment with experimental infusion solutions based on polyglycan derivatives (estimated osmolarity 1026.6, 1784.2, 2566.6 mOsm/l), research of survivability, functional state of cardiovascular and respiratory systems, blood acid-base status and gas partial pressure 5, 30, 60, 120, 180 min after the beginning of replenishment of circulating blood volume. The infusion solution Hemostabil was used as a comparison product. Results. The highest survival rate, restoration of hemodynamics and acid-base state and blood acid-base status and gas partial pressure were obtained as a result of infusion of solution with osmolarity 1026.6 mOsm/l. In this group of animals survivability accounted for 100 %, arterial pressure restored in 5 minutes after the start of infusion, indicators of blood acid-base status and gas partial pressure normalized in 120 min of experiment. All of the results had statistically significant differences (p < 0.05) relative to values in other experimental groups. Conclusions. Sample of solution with osmolarity 1026.6 mOsm/l is the most effective in restoration of hemodynamics of rats with the blood loss up to 50 % of circulating blood volume. The expediency of the researches of safety of this infusion solution based on polyglucan derivatives in the capacity of medication for replenishment acute blood loss is substantiated.

Preclinical evaluation of AGTR1-Targeting molecular probe for colorectal cancer imaging in orthotopic and liver metastasis mouse models

Despite advancements in colorectal cancer (CRC) treatment, the prognosis remains unfavorable for patients with distant liver metastasis. Fluorescence molecular imaging with specific probes is increasingly used to guide CRC surgical resection in real-time and treatment planning. Here, we demonstrate the targeted imaging capacity of an MPA-PEG4-N3-Ang II probe labeled with near-infrared (NIR) fluorescent dye targeting the angiotensin II (Ang II) type 1 receptor (AGTR1) that is significantly upregulated in CRC. MPA-PEG4-N3-Ang II was highly selective and specific to in vitro tumor cells and in vivo tumors in a mouse CRC xenograft model. The favorable ex vivo imaging and in vivo biodistribution of MPA-PEG4-N3-Ang II afforded tumor-specific accumulation with low background and >10 contrast tumor-to-colorectal values in multiple subcutaneous CRC models at 8 h following injection. Biodistribution analysis confirmed the probe's high uptake in HT29 and HCT116 orthotopic and liver metastatic models of CRC with signal-to-noise ratio (SNR) values of tumor-to-colorectal and -liver fluorescence of 5.8 ± 0.6, 5.3 ± 0.7, and 2.7 ± 0.5, 2.6 ± 0.5, respectively, enabling high-contrast intraoperative tumor visualization for surgical navigation. Given its rapid tumor targeting, precise tumor boundary delineation, durable tumor retention and docking study, MPA-PEG4-N3-Ang II is a promising high-contrast imaging agent for the clinical detection of CRC.

Preclinical imaging evaluation of a bispecific antibody targeting hPD1/CTLA4 using humanized mice

BackgroundThe lack of an efficient way to screen patients who are responsive to immunotherapy challenges PD1/CTLA4-targeting cancer treatment. Immunotherapeutic efficacy cannot be clearly determined by peripheral blood analyses, tissue gene markers or CT/MR value. Here, we used a radionuclide and imaging techniques to investigate the novel dual targeted antibody cadonilimab (AK104) in PD1/CTLA4-positive cells in vivo. MethodsFirst, humanized PD1/CTLA4 mice were purchased from Biocytogen Pharmaceuticals (Beijing) Co., Ltd. to express hPD1/CTLA4 in T-cells. Then, mouse colon cancer MC38-hPD-L1 cell xenografts were established in humanized mice. A bispecific antibody targeting PD1/CTLA4 (AK104) was labeled with radio-nuclide iodine isotopes. Immuno-PET/CT imaging was performed using a bispecific monoclonal antibody (mAb) probe 124I-AK104, developed in-house, to locate PD1+/CTLA4+ tumor-infiltrating T cells and monitor their distribution in mice to evaluate the therapeutic effect. ResultsThe 124I-AK104 dual-antibody was successfully constructed with ideal radiochemical characteristics, in vitro stability and specificity. The results of immuno-PET showed that 124I-AK104 revealed strong hPD1/CTLA4-positive responses with high specificity in humanized mice. High uptake of 124I-AK104 was observed not only at the tumor site but also in the spleen. Compared with PD1- or CTLA4-targeting mAb imaging, 124I-AK104 imaging had excellent standard uptake values at the tumor site and higher tumor to nontumor (T/NT) ratios. ConclusionsThe results demonstrated the potential of translating 124I-AK104 into a method for screening patients who benefit from immunotherapy and the efficacy, as well as the feasibility, of this method was verified by immuno-PET imaging of humanized mice.