Magnetic Rubber@Ni-Co layered double hydroxide derived from ZIF-67 template as nanostructured sorbent; application in determination of anticancer drugs in plasma samples.

In this study, a magnetic three-dimensional nano-composite based on Rubber-Fe3O4@Ni-Co Layered double hydroxide derived from ZIF-67 template was synthesized by a hydrothermal method. The proposed nano-composite was used as a sorbent for the enrichment of trace amounts of anti-cancer drugs (dasatinib and erlotinib hydrochloride) from plasma samples followed by determination using high-performance liquid chromatographic analysis (HPLC-UV). The synthesized nano-sorbent was characterized by X-ray diffraction, field emission scanning electron microscopy, Fourier transform infrared spectroscopy, vibrating-sample magnetometer, Brunauer-Emmett-Teller surface analysis, Barrett-Joyner-Halenda pore size analysis and energy dispersive X-ray spectroscopy. Under optimal experimental conditions, factors affecting on extraction efficiency such as pH, ionic strength, extraction temperature and time, desorption solvent and time, the limit of detection (LODs) and the limit of quantification (LOQs) were obtained as 0.6, 2 µg/L for both of dasatinib and erlotinib, respectively. Also, linear range of the method were 2-500 and 2-1000 µg/L for dasatinib and erlotinib, respectively. Relative standard deviations (RSD%) for the repeatability of extraction on sorbent to sorbent were obtained as 3.59, 1.97 %, and one sorbent reusability were investigated and relative standard deviation values were obtained 5.35, 3.30 % for dasatinib and erlotinib, respectively.

Co-assembly of cisplatin and dasatinib in hyaluronan nanogel to combat triple negative breast cancer with reduced side effects.

Treatment for triple negative breast cancer (TNBC) remains a huge challenge due to the lack of targeted therapeutics and tumor heterogenicity. Cisplatin (Cis) have demonstrated favorable therapeutic response in TNBC and thus is used together with various kinase inhibitors to fight the heterogenicity of TNBC. The combination of Cis with SRC inhibitor dasatinib (DAS) has shown encouraging anti-TNBC efficacy although the additive toxicity was commonly observed. To overcome the severe side effects of this Cis involved therapy, here we co-encapsulated Cis and DAS into a self-assembled hyaluronan (HA) nanogel (designated as HA/Cis/DAS (HCD) nanogel) to afford the TNBC targeted delivery by using the 4T1 mouse model. The acquired HCD nanogel was around 181 nm in aqueous solution, demonstrating the pharmacological activities of both Cis and DAS. Taking advantages of HA's targeting capability towards CD44 that is overexpressed on many TNBC cells, the HCD could well maintain the anticancer efficacy of the Cis and DAS combination, significantly increase the maximum tolerated dose and relieve the renal toxicity in vivo. The current HCD nanogel provides a potent strategy to improve the therapeutic outcome of Cis and DAS combination and thus representing a new targeted treatment option for TNBC.

Multiaction Pt(IV) Prodrugs Releasing Cisplatin and Dasatinib Are Potent Anticancer and Anti-Invasive Agents Displaying Synergism between the Two Drugs.

Herein, we describe the general design, synthesis, characterization, and biological activity of new multitargeting Pt(IV) prodrugs that combine antitumor cisplatin and dasatinib, a potent inhibitor of Src kinase. These prodrugs exhibit impressive antiproliferative and anti-invasive activities in tumor cell lines in both two-dimensional (2D) monolayers of cell cultures and three-dimensional (3D) spheroids. We show that the cisplatin moiety and dasatinib in the investigated Pt(IV) complexes are both involved in the mechanism of action in MCF7 breast cancer cells and act synergistically. Thus, combining dasatinib and cisplatin into one molecule, compared to using individual components in a mix, may bring several advantages, such as significantly higher activity in cancer cell lines and higher selectivity for tumor cells. Most importantly, Pt(IV)-dasatinib complexes hold significant promise for potential anticancer therapies by targeting epithelial-mesenchymal transition, thus preventing the spread and metastasis of tumors, a value unachievable by a simple combination of both individual components.

Mix and Shake: A Mild Way to Drug-Loaded Lysozyme Nanoparticles.

Biocompatible nanoparticles as drug carriers can improve the therapeutic efficiency of hydrophobic drugs. However, the synthesis of biocompatible and biodegradable polymeric nanoparticles can be time-consuming and often involves toxic solvents. Here, a simple method for protein-based stable drug-loaded particles with a narrow polydispersity is introduced. In this process, lysozyme is mixed with hydrophobic drugs (curcumin, ellipticine, and dasatinib) and fructose to prepare lysozyme-based drug particles of around 150 nm in size. Fructose is mixed with the drug to generate nanoparticles that serve as templates for the lysozyme coating. The effect of lysozyme on the physicochemical properties of these nanoparticles is studied by transmission electron microscopy (TEM) and scattering techniques (e.g., dynamic light scattering (DLS) and small-angle X-ray scattering (SAXS)). We observed that lysozyme significantly stabilized the curcumin fructose particles for 7 days. Moreover, additional drugs, such as ellipticine and dasatinib, can be loaded to form dual-drug particles with narrow polydispersity and spherical morphology. The results also reveal that lysozyme dual ellipticine/dasatinib curcumin particles enhance the cytotoxicity and uptake on MCF-7 cells, RAW 264.7 cells, and U-87 MG cells due to the larger and rigid hydrophobic core. In summary, lysozyme in combination with fructose and curcumin can serve as a powerful combination to form protein-based stable particles for the delivery of hydrophobic drugs.

Discovery of a Covalent FEM1B Recruiter for Targeted Protein Degradation Applications.

Proteolysis-targeting chimeras (PROTACs), heterobifunctional compounds that consist of protein-targeting ligands linked to an E3 ligase recruiter, have arisen as a powerful therapeutic modality for targeted protein degradation (TPD). Despite the popularity of TPD approaches in drug discovery, only a small number of E3 ligase recruiters are available for the >600 E3 ligases that exist in human cells. Here, we have discovered a cysteine-reactive covalent ligand, EN106, that targets FEM1B, an E3 ligase recently discovered as the critical component of the cellular response to reductive stress. By targeting C186 in FEM1B, EN106 disrupts recognition of the key reductive stress substrate of FEM1B, FNIP1. We further establish that EN106 can be used as a covalent recruiter for FEM1B in TPD applications by demonstrating that a PROTAC linking EN106 to the BET bromodomain inhibitor JQ1 or the kinase inhibitor dasatinib leads to the degradation of BRD4 and BCR-ABL, respectively. Our study showcases a covalent ligand that targets a natural E3 ligase-substrate binding site and highlights the utility of covalent ligand screening in expanding the arsenal of E3 ligase recruiters suitable for TPD applications.

Dasatinib ameliorates thioacetamide-induced liver fibrosis: modulation of miR-378 and miR-17 and their linked Wnt/ß-catenin and TGF-ß/smads pathways.

Hepatic stellate cells activation (HSCs) plays a crucial role in the pathogenesis of liver fibrosis. Specific microRNAs have been suggested to affect the activation of HSCs via various signalling pathways including TGF-ß/smads and Wnt/ß-catenin pathways. Dasatinib is a multitarget inhibitor of many tyrosine kinases has recently studied for its anti-fibrotic effects in a variety of fibrous diseases. This study investigated the role of modulation of miRNA-378 and miRNA-17 in the pathogenesis of liver fibrosis through altering Wnt/ß-catenin and TGF-ß/smads pathways and evaluated the beneficial effect of the tyrosine kinase inhibitor, dasatinib, in thioacetamide-induced liver fibrosis model in mice. Treatment with dasatinib down-regulated miRNA-17 expression, leading to the restoration of WiF-1 and smad-7 which cause the inhibition of both Wnt/ß-catenin and TGF-ß/smads signalling. In addition, it upregulated miRNA-378 leading to the decrease of Wnt-10 which contributes to the suppression of activated HSCs.

Investigation on the interaction behavior of afatinib, dasatinib, and imatinib docked to the BCR-ABL protein.

Chronic myeloid leukemia (CML) is a pathological condition associated with the uncontrolled proliferation of white blood cells and respective loss of function. Imatinib was the first drug that could effectively treat this condition, but its use is hindered by the development of mutations of the BCR-ABL protein, which are the cause of resistance. Therefore, dasatinib and afatinib present similarities that can be explored to discover new molecules capable of overcoming the effects of imatinib. Afatinib exhibited electronic and docking behavior, indicating that a replacement with some minor modifications could design a new potential inhibitor. The amide group in each candidate is clearly of pharmacophoric importance, and it needs to concentrate a negative region. Sulfur group presents a good pharmacophoric profile, which was shown by dasatinib results, adding to the influence of the Met318 residue in the target protein active site configuration. This behavior suggests that the sulfur atom and other fragments that have an affinity for the methionine sidechain may provide a significant positive effect when present in TKI molecules such as afatinib or dasatinib.

Development of UPLC-MS/MS Method for Studying the Pharmacokinetic Interaction Between Dasatinib and Posaconazole in Rats.

BACKGROUND AND AIM: Dasatinib is approved for the treatment of leukaemia worldwide. Triazole agents such as posaconazole may be used for the control of secondary fungal infection with leukaemia. This work aimed to develop a bioanalytical method to study the potential interaction between dasatinib and posaconazole. METHODS: An ultrahigh-performance liquid chromatography-tandem mass spectrometry method was established to measure the plasma concentrations of dasatinib and posaconazole in rats simultaneously. Simple protein precipitation with acetonitrile was applied to extract dasatinib and posaconazole in samples. The chromatographic separation of analytes was conducted on an UPLC BEH C18 column using a mobile phase consisting of 0.1% aqueous formic acid and acetonitrile. Dasatinib and posaconazole were monitored in positive ion mode with the following mass transition pairs: m/z 488.2→401.1 for dasatinib and m/z 701.3→683.4 for posaconazole. The method was successfully applied for pharmacokinetic interaction between dasatinib and posaconazole. RESULTS: The established method expressed good linearity in 1-1000 ng/mL of dasatinib and 5-5000 ng/mL of posaconazole, with limit of detection was 1 ng/mL and 5 ng/mL, respectively. Methodology validations, including accuracy, precision, matrix effect, recovery, and stability, met the US Food and Drug Administration (FDA) acceptance criteria for bioanalytical method validation. Dasatinib strongly inhibited the clearance of posaconazole in vivo, while posaconazole expressed no significant effect on the pharmacokinetics of dasatinib. CONCLUSION: Dasatinib alters the pharmacokinetics of posaconazole. Attention should be paid to the unexpected risk of adverse clinical outcomes when posaconazole is co-administered with dasatinib.

A small molecule nanodrug consisting of pH-sensitive ortho ester-dasatinib conjugate for cancer therapy.

The main objective of this paper is to develop a self-delivered prodrug system with nanoscale characteristics to enhance the efficacy of tumor therapy. The pH-sensitive prodrug was composed of ortho ester-linked dasatinib (DAS-OE), which was further self-assembled with or without doxorubicin (DOX) to obtain two carrier-free nanoparticles (DOX/DAS-OE NPs or DAS-OE NPs). The prodrug-based nanoparticles united the superiorities of small molecules and nano-assemblies together and displayed well-defined structure, uniform spherical shape, high drug loading ratio and on-demand drug release behavior. The drug loading content of DAS and DOX was 61.6% and 21.9%, respectively, and more than 80.2% of DAS and 60.2% DOX were released from DOX/DAS-OE NPs within 20 h at pH 5.0. Both in vitro and in vivo studies demonstrated that the pH-sensitive ortho ester bonds in the prodrug underwent hydrolysis to release DAS and DOX simultaneously after cellular internalization, resulting in remarkable antitumor effect. Tumor growth inhibition rate was 19.9% (free DAS), 35.5% (free DOX), 66.3% (DAS-OE NPs) and 82.8% (DOX/DAS-OE NPs), respectively. Thus, the ortho ester-linked prodrug system shows great potentials in cancer therapy.

Effect of Dasatinib on Genes Related to Mitotic Catastrophe Pathway in Chronic Myeloid Leukemia Cells.

BACKGROUND: Chronic Myeloid Leukemia (CML) is characterized by a reciprocal translocation t(9;22) and forms BCR/ABL1 fusion gene called the Philadelphia chromosome. The therapeutic targets for CML patients mediated with BCR/ABL1 oncogenic are tyrosine kinase inhibitors such as imatinib, dasatinib, and nilotinib. The latter two of which have been approved for the treatment of imatinib-resistant or intolerance CML patients. Mitotic Catastrophe (MC) is one of the non-apoptotic mechanisms initiated in types of cancer cells in response to anti-cancer therapies. Pharmacological inhibitors of G2 checkpoint members or genetic suppression of PLK1, PLK2, ATR, ATM, CHK1, and CHK2 can trigger DNA-damage-stimulated mitotic catastrophe. PLK1 and AURKA/B are anomalously expressed in CML cells, where phosphorylation and activation of PLK1 occur by AURKB at centromeres and kinetochores. OBJECTIVE: The purpose of this study is to investigate the effect of dasatinib on the expression of genes in MC and apoptosis pathways in K562 cells. METHODS: Total RNA was isolated from K-562 cells treated with the IC50 value of dasatinib and untreated cells as a control group. The expression of MC and apoptosis-related genes, was analyzed by the qRT-PCR system. RESULTS: The array-data demonstrated that dasatinib-treated K562 cells significantly caused the decrease of several genes (AURKA, AURKB, PLK, CHEK1, MYC, XPC, BCL2, and XRCC2). CONCLUSION: The evidence supplies a basis to support clinical researches for the suppression of oncogenes such as PLKs with AURKs in the treatment of types of cancer, especially chronic myeloid leukemia.

Novel Targeted Photosensitizer as an Immunomodulator for Highly Efficient Therapy of T-Cell Acute Lymphoblastic Leukemia.

Dasatinib is a kinase-targeted drug used in the treatment of leukemia. Regrettably, it remains far from optimal medicine due to insurmountable drug resistance and side effects. Photodynamic therapy (PDT) has proven that it can induce systemic immune responses. However, conventional photosensitizers as immunomodulators produce anticancer immunities, which are inadequate to eliminate residual cancer cells. Herein, a novel compound 4 was synthesized and investigated, which introduces dasatinib and zinc(II) phthalocyanine as the targeting and photodynamic moiety, respectively. Compound 4 exhibits a high affinity to CCRF-CEM cells/tumor tissues, which overexpress lymphocyte-specific protein tyrosine kinase (LCK), and preferential elimination from the body. Meanwhile, compound 4 shows excellent photocytotoxicity and tumor regression. Significantly, compound 4-induced PDT can obviously enhance immune responses, resulting in the production of more immune cells. We believe that the proposed manner is a potential strategy for the treatment of T-cell acute lymphoblastic leukemia.

Differential impact of BTK active site inhibitors on the conformational state of full-length BTK.

Bruton's tyrosine kinase (BTK) is targeted in the treatment of B-cell disorders including leukemias and lymphomas. Currently approved BTK inhibitors, including Ibrutinib, a first-in-class covalent inhibitor of BTK, bind directly to the kinase active site. While effective at blocking the catalytic activity of BTK, consequences of drug binding on the global conformation of full-length BTK are unknown. Here, we uncover a range of conformational effects in full-length BTK induced by a panel of active site inhibitors, including large-scale shifts in the conformational equilibria of the regulatory domains. Additionally, we find that a remote Ibrutinib resistance mutation, T316A in the BTK SH2 domain, drives spurious BTK activity by destabilizing the compact autoinhibitory conformation of full-length BTK, shifting the conformational ensemble away from the autoinhibited form. Future development of BTK inhibitors will need to consider long-range allosteric consequences of inhibitor binding, including the emerging application of these BTK inhibitors in treating COVID-19.

Treatments for blood cancers, such as leukemia and lymphoma, rely heavily on chemotherapy, using drugs that target a vulnerable aspect of the cancer cells. B-cells, a type of white blood cell that produces antibodies, require a protein called Bruton's tyrosine kinase, or BTK for short, to survive. The drug ibrutinib (Imbruvica) is used to treat B-cell cancers by blocking BTK. The BTK protein consists of several regions. One of them, known as the kinase domain, is responsible for its activity as an enzyme (which allows it to modify other proteins by adding a 'tag' known as a phosphate group). The other regions of BTK, known as regulatory modules, control this activity. In BTK's inactive form, the regulatory modules attach to the kinase domain, blocking the regulatory modules from interacting with other proteins. When BTK is activated, it changes its conformation so the regulatory regions detach and become available for interactions with other proteins, at the same time exposing the active kinase domain. Ibrutinib and other BTK drugs in development bind to the kinase domain to block its activity. However, it is not known how this binding affects the regulatory modules. Previous efforts to study how drugs bind to BTK have used a version of the protein that only had the kinase domain, instead of the full-length protein. Now, Joseph et al. have studied full-length BTK and how it binds to five different drugs. The results reveal that ibrutinib and another drug called dasatinib both indirectly disrupt the normal position of the regulatory domains pushing BTK toward a conformation that resembles the activated state. By contrast, the three other compounds studied do not affect the inactive structure. Joseph et al. also examined a mutation in BTK that confers resistance against ibrutinib. This mutation increases the activity of BTK by disrupting the inactive structure, leading to B cells surviving better. Understanding how drug resistance mechanisms can work will lead to better drug treatment strategies for cancer. BTK is also a target in other diseases such as allergies or asthma and even COVID-19. If interactions between partner proteins and the regulatory domain are important in these diseases, then they may be better treated with drugs that maintain the regulatory modules in their inactive state. This research will help to design drugs that are better able to control BTK activity.

Targeting Tumor-Associated Macrophages by MMP2-Sensitive Apoptotic Body-Mimicking Nanoparticles.

Tumor-associated macrophages (TAMs), a major player in the tumor microenvironment, were recently recognized as a potential therapeutic target. To date, very few anticancer drugs or drug-delivery systems were designed to target the TAMs. Inspired by the "eat me" signal, phosphatidylserine (PS), mediated phagocytic clearance of apoptotic bodies, in this study, the matrix metalloproteinase 2 (MMP2)-sensitive PS-modified nanoparticles were developed. In the design, the PS is externalized to the nanoparticles' surface only when the nanoparticles reach the MMP2-overexpressing tumor site, allowing for the TAM-specific phagocytosis. The nanoparticles' excellent macrophage/TAM selectivity was observed in various biological models, including various cell lines, coculture cells, coculture cell spheroids, zebrafish, and tumor-bearing mice. The nanoparticles' TAM specificity remarkably enhanced the TAM depletion capability of the loaded model drug, dasatinib, resulting in the improved anticancer activity. The MMP2-sensitive apoptotic body-mimicking nanoparticles might be a promising delivery tool for TAM-centered cancer diagnoses and treatments.

Is breaking of a hydrogen bond enough to lead to drug resistance?

Drug resistance is a serious problem in cancer, viral, bacterial, fungal and parasitic diseases. Examination of crystal structures of protein-drug complexes is often not enough to explain why a certain mutation leads to drug resistance. As an example, the crystal structure of the kinase inhibitor dasatinib bound to the Abl1 kinase shows a hydrogen bond between the drug and residue Thr315 and very few contacts between the drug and residues Val299 and Phe317, yet mutations in those residues lead to drug resistance. In the first case, it is tempting to suggest that the loss of a hydrogen bond leads to drug resistance, whereas in the other two cases it is not known why mutations lead to drug resistance in the first place. We carried out extensive molecular dynamics (MD) simulations and free energy calculations to explain drug resistance to dasatinib from a molecular point of view and show that resistance is due to a multitude of subtle effects. Importantly, our calculations could reproduce the experimental values for the binding energies upon mutations in all three cases and shed light on their origin.

In Situ Study of the Drug-Target Protein Interaction in Single Living Cells by Combining Fluorescence Correlation Spectroscopy with Affinity Probes.

The drug-target protein interaction is the basis of drug screening and precise therapy in modern clinical medicine. How to acquire the information about the drug-target protein interaction in single living cell is a great challenge due to the shortage of efficient methods. Here we propose a new strategy for in situ studying the drug-target protein interaction in single living cells based on the competition of candidate drugs to the fluorescent probe-target complexes and fluorescence correlation spectroscopy (FCS) with a microfluidic chip. In this study, we used ABL kinase (target) as a model and synthesized a fluorescent probe (Cy3-dasatinib) with an affinity to the target using ABL inhibitor dasatinib as a precursor. We systematically investigated the association of the probe with targets and the dissociation of the drug-target complexes in the presence of candidate drug. We presented a new parameter IC50 (τD) to assess the inhibitory effect of drugs on the basis of the changes in the characteristic diffusion time (τD) and the binding ratio (y) of fluorescent probes during the drug competition process in living cells. We found a remarkable difference of IC50 (τD) values in living cells and in solutions, suggesting it is quite necessary to evaluate the drug-target interactions in living cells. Compared with current methods, our approach can be used to in situ and real-time study the drug-target interaction in living cells, and it may become a promising and universal tool for in situ drug research at molecular level.

Micelles entrapped microparticles technology: a novel approach to resolve dissolution and bioavailability problems of poorly water soluble drugs.

Aim: Aim of this study was to design a solid oral delivery system for a weakly basic drug such as dasatinib (DAS), so as to achieve pH-independent dissolution and improved oral bioavailability.Methods: DAS was solubilised using sodium lauryl sulphate as an aqueous micellar system and such a system containing lactose monohydrate as carrier was spray-dried to obtain a solid mass. Subsequently, the DAS-solid was converted into a tablet using conventional tableting methods.Results: The dissolution study revealed pH-independent dissolution over a wide range of pH conditions. An in vivo bioavailability testing on rats revealed an improved Cmax and AUC0-24. Similarly, viability assay showed a better inhibitory effect of spray-dried dasatinib over the DAS.Conclusions: Micellar solubilisation and spray-drying technology can be approached to resolve poor dissolution and bioavailability of drugs belonging to biopharmaceutical classification system II and III. This technology is amenable to scale-up and has commercial potential.

Novel high-performance liquid chromatography-tandem mass spectrometry method for simultaneous quantification of BCR-ABL and Bruton's tyrosine kinase inhibitors and their three active metabolites in human plasma.

Therapeutic drug monitoring is important in patients taking BCR-ABL and Bruton's tyrosine kinase inhibitors (TKIs). Some TKI active metabolites with long elimination half-lives, such as dihydrodiol ibrutinib (DHI), N-desmethyl imatinib (N-DI), and N-desmethyl ponatinib (N-DP), have been characterized, indicating that these active metabolites should be monitored along with the parent compounds. However, there are currently no methods for the simultaneous quantification of BCR-ABL and Bruton's TKIs and their three active metabolites. The present study aimed to develop and validate a method for the simultaneous quantification of nine pharmacologically active compounds (bosutinib, dasatinib, DHI, ibrutinib, imatinib, N-DI, N-DP, nilotinib, and ponatinib) using high-performance liquid chromatography-tandem mass spectrometry. A 150-µL sample of plasma was analyzed after purification with supported liquid extraction. The method has a run time of 7 min and was successfully validated over the following calibration ranges: 0.25-75 ng/mL for N-DP, 0.5-150 ng/mL for dasatinib and ponatinib, 10-3000 ng/mL for imatinib and nilotinib, and 1-300 ng/mL for the other analytes. Stability of the analytes after short- and long-term storage in the presence of plasma matrix was examined, and all analytes were found to be stable under all tested conditions. The recovery was ≥83%, and the relative standard deviation of internal-standard normalized matrix effects ranged from 3.9 to 13.9%. Dilution integrity up to 4-fold was ensured. The applicability of the method for all analytes was demonstrated using patient samples.

Ultrasmall Core-Shell Silica Nanoparticles for Precision Drug Delivery in a High-Grade Malignant Brain Tumor Model.

PURPOSE: Small-molecule inhibitors have revolutionized treatment of certain genomically defined solid cancers. Despite breakthroughs in treating systemic disease, central nervous system (CNS) metastatic progression is common, and advancements in treating CNS malignancies remain sparse. By improving drug penetration across a variably permeable blood-brain barrier and diffusion across intratumoral compartments, more uniform delivery and distribution can be achieved to enhance efficacy. EXPERIMENTAL DESIGN: Ultrasmall fluorescent core-shell silica nanoparticles, Cornell prime dots (C' dots), were functionalized with αv integrin-binding (cRGD), or nontargeting (cRAD) peptides, and PET labels (124I, 89Zr) to investigate the utility of dual-modality cRGD-C' dots for enhancing accumulation, distribution, and retention (ADR) in a genetically engineered mouse model of glioblastoma (mGBM). mGBMs were systemically treated with 124I-cRGD- or 124I-cRAD-C' dots and sacrificed at 3 and 96 hours, with concurrent intravital injections of FITC-dextran for mapping blood-brain barrier breakdown and the nuclear stain Hoechst. We further assessed target inhibition and ADR following attachment of dasatinib, creating nanoparticle-drug conjugates (Das-NDCs). Imaging findings were confirmed with ex vivo autoradiography, fluorescence microscopy, and p-S6RP IHC. RESULTS: Improvements in brain tumor delivery and penetration, as well as enhancement in the ADR, were observed following administration of integrin-targeted C' dots, as compared with a nontargeted control. Furthermore, attachment of the small-molecule inhibitor, dasatinib, led to its successful drug delivery throughout mGBM, demonstrated by downstream pathway inhibition. CONCLUSIONS: These results demonstrate that highly engineered C' dots are promising drug delivery vehicles capable of navigating the complex physiologic barriers observed in a clinically relevant brain tumor model.

UPLC-MS/MS study of the effect of dandelion root extract on the plasma levels of the selected irreversible tyrosine kinase inhibitors dasatinib, imatinib and nilotinib in rats: Potential risk of pharmacokinetic interactions.

Tyrosine kinase inhibitor treatments for chronic myeloid leukaemia based on nilotinib (NIL), dasatinib (DAS) and imatinib (IMA) have improved patient quality of life and have turned chronic myeloid leukemia from a fatal disease into a chronic disease. Dandelion is a rich source of phenolic compounds with strong biological properties, and the effects of using this plant in the treatment of different illnesses can be linked to the presence of various polyphenols found in the different parts of the plant. Thus, dandelion can potentially be used as a nutraceutical (dietary antioxidant) to prevent different disorders associated with oxidative stress, i.e. cardiovascular disorders, cancer and inflammatory processes. Mutual interference between a drug and a food constituent may result in altered pharmacokinetics of the drug and undesired or even dangerous clinical situations. In the present study, a bioanalytical ultra performance liquid chromatography-tandem mass spectrometer (UPLC-MS/MS) method was developed and validated for the quantification of DAS, IMA and NIL in rat plasma. Sample preparation was carried out using solid-phase extraction with C18 cartridges with a good extraction recovery of ≥94.37% for the three drugs. The method was fully validated as per the US Food and Drug Administration guidelines.

An Algorithm for Building Multi-State Classifiers Based on Collision-Induced Unfolding Data.

Collision-induced unfolding (CIU) has emerged as a valuable method for distinguishing iso-cross-sectional protein ions through their distinct gas-phase unfolding trajectories. CIU shows promise as a high-throughput, structure-sensitive screening technique with potential applications in drug discovery and biotherapeutic characterization. We recently developed a CIU classification workflow to support screening applications that utilized CIU data acquired from a single protein charge state to distinguish immunoglobulin (IgG) subtypes and membrane protein lipid binding. However, distinguishing highly similar protein structures, such as those associated with biotherapeutics, can be challenging. Here, we present an expansion of this classification method that includes CIU data from multiple charge states, or indeed any perturbation to protein structure that differentially affects CIU, into a combined classifier. Using this improved method, we are able to improve the accuracy of existing, single-state classifiers for IgG subtypes and develop an activation-state-sensitive classifier for selected Src kinase inhibitors when data from a single charge state was insufficient to do so. Finally, we employ the combination of multiple charge states and stress conditions to distinguish a highly similar innovator/biosimilar biotherapeutic pair, demonstrating the potential of CIU as a rapid screening tool for drug discovery and biotherapeutic analysis.