Morphology-Mediated Tumor Deep Penetration for Enhanced Near Infrared II Photothermal and Chemotherapy of Colorectal Cancer.

The low permeability and heterogeneous distribution of drugs (including nanomedicines) have limited their deep penetration into solid tumors. Herein we report the design of gold nanoparticles with virus-like spikes (AuNVs) to mimic viral shapes and facilitate tumor penetration. Mechanistic studies revealed that AuNVs mainly entered cells through macropinocytosis, then transported to the Golgi/endoplasmic reticulum system via Rab11-regulated pathway, and finally exocytosed through recycling endosomes, leading to high cellular uptake, effective transcytosis, and deep tumor penetration compared to gold nanospheres (AuNPs) and gold nanostars (AuNSs). The high tumor accumulation and deep tumor penetration of mitoxantrone (MTO) facilitated by AuNVs endowed effective chemophotothermal therapy when exposed to a near-infrared II laser, significantly reducing tumor sizes in a mouse model of colorectal cancer. This study reveals a potent mechanism of viral-like structures in tissue penetration and highlights their potential as effective drug delivery carriers.

Population pharmacokinetics of free and liposome-encapsulated mitoxantrone in patients with relapsed/refractory lymphoma or small cell lung cancer.

OBJECTIVE: This study is aimed at investigating the pharmacokinetic (PK) characteristics of pegylated liposomal mitoxantrone (PLM) in patients with relapsed/refractory lymphoma or small cell lung cancer (SCLC) by constructing population pharmacokinetic (popPK) models for both liposome-encapsulated mitoxantrone and free mitoxantrone. METHODS: A total of 23 patients with relapsed/refractory lymphoma and 42 patients with SCLC were included. A popPK model was simultaneously developed utilizing a non-linear mixed effects model (NONMEM) to explore the PK profiles of liposome-encapsulated mitoxantrone and free mitoxantrone. Clearance (CL) and distribution volume (V) were calculated, and covariate analysis was employed to evaluate the influence of patient disease type, demographic information, and biochemical indicators of liver and kidney function on PK parameters. RESULTS: The concentration-time profiles for both liposome-encapsulated mitoxantrone and free mitoxantrone were described by a one-compartment model. The release (Rel) of liposome-encapsulated mitoxantrone to free mitoxantrone was determined to be 0.0191 L/h, and the V of liposome-encapsulated mitoxantrone was 2.32 L. The apparent CL of free mitoxantrone was estimated at 1.66 L/h. The apparent V of free mitoxantrone was 35.8 L in patients with relapsed/refractory lymphoma and 22.2 L for patients with SCLC. In patients with relapsed/refractory lymphoma, lower maximum concentration (Cmax) and higher apparent V of free mitoxantrone were observed compared with patients with SCLC. CONCLUSION: The popPK characteristics of both liposome-encapsulated and free mitoxantrone in patients with relapsed/refractory lymphoma or SCLC were effectively described by a one-compartment model.

Cholesterol sulfate-mediated ion-pairing facilitates the self-nanoassembly of hydrophilic cationic mitoxantrone.

HYPOTHESIS: Hydrophilic cationic drugs such as mitoxantrone hydrochloride (MTO) pose a significant delivery challenge to the development of nanodrug systems. Herein, we report the use of a hydrophobic ion-pairing strategy to enhance the nano-assembly of MTO. EXPERIMENTS: We employed biocompatible sodium cholesteryl sulfate (SCS) as a modification module to form stable ion pairs with MTO, which balanced the intermolecular forces and facilitated nano-assembly. PEGylated MTO-SCS nanoassemblies (pMS NAs) were prepared via nanoprecipitation. We systematically evaluated the effect of the ratio of the drug module (MTO) to the modification module (SCS) on the nanoassemblies. FINDINGS: The increased lipophilicity of MTO-SCS ion pair could significantly improve the encapsulation efficiency (∼97 %) and cellular uptake efficiency of MTO. The pMS NAs showed prolonged blood circulation, maintained the same level of tumor antiproliferative activity, and exhibited reduced toxicity compared with the free MTO solution. It is noteworthy that the stability, cellular uptake, cytotoxicity, and in vivo pharmacokinetic behavior of the pMS NAs increased in proportion to the molar ratio of SCS to MTO. This study presents a self-assembly strategy mediated by ion pairing to overcome the challenges commonly associated with the poor assembly ability of hydrophilic cationic drugs.

Hydrogel-Coated SERS Microneedles for Drug Monitoring in Dermal Interstitial Fluid.

In vivo drug monitoring is crucial for evaluating the effectiveness and safety of drug treatment. Blood sampling and analysis is the current gold standard but needs professional skills and cannot meet the requirements of point-of-care testing. Dermal interstitial fluid (ISF) showed great potential to replace blood for in vivo drug monitoring; however, the detection was challenging, and the drug distribution behavior in ISF was still unclear until now. In this study, we proposed surface-enhanced Raman spectroscopy (SERS) microneedles (MNs) for the painless and real-time analysis of drugs in ISF after intravenous injection. Using methylene blue (MB) and mitoxantrone (MTO) as model drugs, the innovative core-satellite structured Au@Ag SERS substrate, hydrogel coating over the MNs, rendered sensitive and quantitative drug detection in ISF of mice within 10 min. Based on this technique, the pharmacokinetics of the two drugs in ISF was investigated and compared with those in blood, where the drugs were analyzed via liquid chromatography-mass spectrometry. It was found that the MB concentration in ISF and blood was comparable, whereas the concentration of MTO in ISF was 2-3 orders of magnitude lower than in blood. This work proposed an efficient tool for ISF drug monitoring. More importantly, it experimentally proved that the penetration ratio of blood to ISF was drug-dependent, providing insightful information into the potential of ISF as a blood alternative for in vivo drug detection.

Self-Supplied Reactive Oxygen Species-Responsive Mitoxantrone Polyprodrug for Chemosensitization-Enhanced Chemotherapy under Moderate Hyperthermia.

Currently, the secondary development and modification of clinical drugs has become one of the research priorities. Researchers have developed a variety of TME-responsive nanomedicine carriers to solve certain clinical problems. Unfortunately, endogenous stimuli such as reactive oxygen species (ROS), as an important prerequisite for effective therapeutic efficacy, are not enough to achieve the expected drug release process, therefore, it is difficult to achieve a continuous and efficient treatment process. Herein, a self-supply ROS-responsive cascade polyprodrug (PMTO) is designed. The encapsulation of the chemotherapy drug mitoxantrone (MTO) in a polymer backbone could effectively reduce systemic toxicity when transported in vivo. After PMTO is degraded by endogenous ROS of the TME, another part of the polyprodrug backbone becomes cinnamaldehyde (CA), which can further enhance intracellular ROS, thereby achieving a sustained drug release process. Meanwhile, due to the disruption of the intracellular redox environment, the efficacy of chemotherapy drugs is enhanced. Finally, the anticancer treatment efficacy is further enhanced due to the mild hyperthermia effect of PMTO. In conclusion, the designed PMTO demonstrates remarkable antitumor efficacy, effectively addressing the limitations associated with MTO.

Subchronic administration of mitoxantrone and the influence of enzyme inhibitors on its induced cardiotoxicity in mice: role of NRF-2/CYP2E1.

OBJECTIVE: Mitoxantrone (MTX)- induced cardiotoxicity is a clinical concern that is limiting its use. The aim of this paper, therefore, was to investigate the subchronic administration of MTX plus nonspecific/specific inhibitors of CYP450/2E1, to assess the extent of oxidative-induced injury by measuring levels of oxidative cardiac and injury biomarkers in mice and to evaluate the effects of CYP2E1 on caspase 3 activity and nuclear factor erythroid 2-related factor-2 (NRF-2). MATERIALS AND METHODS: Mice (n = 32) were divided into four treatment groups of eight: control, MTX, MTX + 4-methlypyrazole (4MP) and MTX + disulfiram (Disf). After 6 weeks of treatments, blood and heart samples were collected. RESULTS: Liquid chromatography-mass spectrometry (LCMS) analysis of MTX-treated plasma samples revealed several metabolites with different retention times. Cardiac antioxidant enzymes and creatine kinase (CK) levels were not significantly different among the groups. However, cardiac troponin and caspase 3 activity were significantly raised, with increased CYP2E1 expressions and reduced NRF-2 expression. Tissue damage was observed in all the treatment groups, including MTX, leading to the conclusion that MTX-induced cardiotoxicity was mediated by CYP2E1 activity, which initiated caspase 3 production, and decreased NRF-2 expression. CONCLUSIONS: Therefore, agents that inhibit CPY2E1 expression might attenuate MTX-induced cardiotoxicity by increasing NRF-2 expression.

Evaluation of inhibitory effects of flavonoids on breast cancer resistance protein (BCRP): From library screening to biological evaluation to structure-activity relationship.

Flavonoids are a group of polyphenols ubiquitously present in vegetables, fruits and herbal products, despite various known pharmacological activities, few researches have been done about the interaction of flavonoids with breast cancer resistance protein (BCRP). The present study was designed to investigate the inhibitory effects of 99 flavonoids on BCRP in vitro and in vivo and to clarify structure-activity relationships of flavonoids with BCRP. Eleven flavonoids, including amentoflavone, apigenin, biochanin A, chrysin, diosimin, genkwanin, hypericin, kaempferol, kaempferide, licochalcone A and naringenin, exhibited significant inhibition (>50%) on BCRP in BCRP-MDCKII cells, which reduced the BCRP-mediated efflux of doxorubicin and temozolomide, accordingly increased their cytotoxicity. In addition, co-administration of mitoxantrone with the 11 flavonoids increased the AUC0-t of mitoxantrone in different extents in rats. Among them, chrysin increased the AUC0-t most significantly, by 81.97%. Molecular docking analysis elucidated the inhibition of flavonoids on BCRP might be associated with Pi-Pi stacked interactions and/or potential Pi-Alkyl interactions, but not conventional hydrogen bonds. The pharmacophore model indicated the aromatic ring B, hydrophobic groups and hydrogen bond acceptors may play critical role in the potency of flavonoids inhibition on BCRP. Thus, our findings would provide helpful information for predicting the potential risks of flavonoid-containing food/herb-drug interactions in humans.

Pilot study comparing serum chemotherapy levels after intra-arterial and intravenous administration in dogs with naturally occurring urinary tract tumors.

The proposed advantages of intra-arterial chemotherapy (IAC) are based on the premises of local dose escalation to the tumor and reduced availability of systemic drugs. There is a lack of objective pharmacokinetic data to confirm the advantage of IAC in dogs with naturally occurring urogenital tumors. The objective of this study was to determine if IAC administration in urogenital tumors would result in decreased systemic drug exposure when compared to intravenous routes. Twenty-two dogs with naturally occurring urogenital tumors were enrolled in this prospective case-controlled study. Mitoxantrone, doxorubicin, or carboplatin were administered by IAC and intravenous routes [intravenous awake (intravenous chemotherapy - IVC) and under general anesthesia (IVGAC)] 3 weeks apart. Serum assays were used to determine the extent of systemic drug exposure. Dose-normalized peak systemic serum concentration (Cmax) and area under the serum drug concentration-time curve (AUC) were used to quantify systemic exposure. A total of 26 mitoxantrone treatments were administered to 10 dogs. While there was no significant difference in Cmax, the AUC was significantly lower after IAC compared with IVGAC. Ten doxorubicin treatments were administered to 5 dogs. There were no significant differences in Cmax or AUC. A total of 14 carboplatin treatments were administered to 7 dogs. The Cmax was significantly lower for IAC compared to IVC, while the AUC values were equivocal. This study demonstrates certain lower serum values may be achieved after IAC delivery of carboplatin and mitoxantrone. These chemotherapy agents may have a preferred pharmacological profile for regional chemotherapy delivery in dogs with urogenital tumors.

Les avantages proposés de la chimiothérapie intra-artérielle (CIA) sont basés sur les prémisses d'une escalade de la dose locale à la tumeur et d'une disponibilité réduite des drogues systémiques. Il y a un manque de données pharmacocinétiques objectives pour confirmer l'avantage de l'administration de CIA chez les chiens avec des tumeurs urogénitales se produisant naturellement. L'objectif de la présente étude était de déterminer si l'administration de CIA lors de tumeurs urogénitales résulterait en une diminution de l'exposition systémique aux drogues lorsque comparé aux voies intraveineuses. Vingt-deux chiens avec des tumeurs urogénitales d'occurrence naturelle participèrent à cette étude cas-témoin prospective. De la mitoxantrone, de la doxorubicine, ou de la carboplatine furent administrées par CIA et voies intraveineuses [intraveineuse éveillée (chimiothérapie intraveineuse ­ CIV) et sous anesthésie générale (CIVAG)] à 3 sem d'intervalle. Des analyses du sérum furent utilisées afin de déterminer l'étendue de l'exposition systémique aux drogues. Le pic de la concentration sérique systémique normalisé pour la dose (Cmax) et la surface sous la courbe de la concentration sérique de la drogue-temps (SSC) furent utilisés pour quantifier l'exposition systémique. Un total de 26 traitements à la mitoxantrone fut administré à 10 chiens. Bien qu'il n'y ait pas de différence significative dans le Cmax, la SSC était significativement plus basse après la CIA comparativement à la CIVAG. Dix traitements de doxorubicine furent administrés à cinq chiens. Il n'y avait pas de différence significative dans le Cmax ou ls SSC. Un total de 14 traitements de carboplatine fut administré à sept chiens. Le Cmax était significativement plus bas pour la CIA comparativement à la CIV, alors que les valeurs de SSC étaient équivoques. Cette étude démontre que certaines valeurs sériques plus faibles peuvent être obtenues après CIA avec la carboplatine et la mitoxantrone. Ces agents de chimiothérapie pourraient avoir un profil pharmacologique préférentiel pour livraison régionale de chimiothérapie chez les chiens avec des tumeurs urogénitales.(Traduit par Docteur Serge Messier).

A smart drug-delivery nanosystem based on carboxylated graphene quantum dots for tumor-targeted chemotherapy.

Aim: Constructing a new drug-delivery system using carboxylated graphene quantum dots (cGQDs) for tumor chemotherapy in vivo. Materials & methods: A drug-delivery system was synthesized through a crosslink reaction of cGQDs, NH2-poly(ethylene glycol)-NH2 and folic acid. Results: A drug delivery system of folic acid-poly(ethylene glycol)-cGQDs was successfully constructed with ideal entrapment efficiency (97.5%) and drug-loading capacity (40.1%). Cell image indicated that the nanosystem entered into human cervical cancer cells mainly through macropinocytosis-dependent pathway. In vivo experiments showed the outstanding antitumor ability and low systemic toxicity of this nanodrug-delivery system. Conclusion: The newly developed drug-delivery system provides an important alternative for tumor therapy without causing systemic adverse effects.

A surfactant-like chemotherapeutic agent as a nanocarrier for delivering photosensitizers against cancer: A facile drug-delivering-drug strategy.

Photosensitizer-based photodynamic therapy (PDT) has attracted great attention in cancer treatment. However, achieving efficient delivery of photosensitizers is still a great challenge for their clinical applications. The photosensitizer-encapsulating delivery nanosystem usually suffers from poor stability, complex preparation process and low drug loading. Herein, we utilize a surfactant-like chemotherapeutic agent, mitoxantrone (MTX), as a nanocarrier to deliver a photosensitizer pyropheophorbide a (PPa) for antitumor therapy. MTX consists of aromatic rings (hydrophobic part) and two amino-groups and two hydroxyl-groups (hydrophilic part) with planar structure, which could interact with PPa via π-π stacking, hydrophobic interactions, intermolecular hydrogen bonding and electrostatic interactions. This system (PPa@MTX) spontaneously forms near-spherical nanostructures (∼150 nm), has a high loading capacity for PPa (56.5%) and exhibits a pH-responsive drug release manner in vitro. In vivo antitumor efficacy evaluations show that the pegylated PPa@MTX nanosystem has increased accumulation in tumor tissues and enhanced antitumor efficacy in female BALB/c mice bearing murine mammary carcinoma (4T1) tumor cells, compared to free PPa. Employing the surfactant-like drug as nanocarriers, our results show that the "drug-delivering-drug" strategy is a good foundation for the development of novel PDT-based drug delivery system against cancer.

Selonsertib (GS-4997), an ASK1 inhibitor, antagonizes multidrug resistance in ABCB1- and ABCG2-overexpressing cancer cells.

Overexpression of ATP-binding cassette (ABC) transporters is one of the most important mechanisms responsible for the development of multidrug resistance (MDR). Selonsertib, a serine/threonine kinase inhibitor, targets apoptosis signal-regulating kinase 1 (ASK1) and is now in phase III clinical trial for the treatment of non-alcoholic steatohepatitis (NASH). In this study, we investigated whether selonsertib could reverse MDR-mediated by ABC transporters, including ABCB1, ABCG2, ABCC1 and ABCC10. The results showed that selonsertib significantly reversed ABCB1- and ABCG2-mediated MDR, but not MDR-mediated by ABCC1 or ABCC10. Mechanism studies indicated that the reversal effect of selonsertib was related to the attenuation of the efflux activity of ABCB1 and ABCG2 transporters, without the protein level decrease or change in the subcellular localization of ABCB1 or ABCG2. Selonsertib stimulated the ATPase activity of ABCB1 and ABCG2 in a concentration-dependent manner, and in silico docking study showed selonsertib could interact with the substrate-binding sites of both ABCB1 and ABCG2. This study provides a clue into a novel treatment strategy, which includes a combination of selonsertib with antineoplastic drugs to attenuate MDR-mediated by ABCB1 or ABCG2 in cancer cells overexpressing these transporters.

Pharmacokinetics, distribution and anti-tumor efficacy of liposomal mitoxantrone modified with a luteinizing hormone-releasing hormone receptor-specific peptide.

BACKGROUND: A previous study developed a novel luteinizing hormone-releasing hormone (LHRH) receptor-targeted liposome. The aim of this study was to further assess the pharmacokinetics, biodistribution, and anti-tumor efficacy of LHRH receptor-targeted liposomes loaded with the anticancer drug mitoxantrone (MTO). METHODS: Plasma and tissue distribution profiles of LHRH receptor-targeted MTO-loaded liposomes (LHRH-MTO-LIPs) were quantified in healthy mice or a xenograft tumor nude mouse model of MCF-7 breast cancer, and were compared with non-targeted liposomes and a free-drug solution. RESULTS: The LHRH-MTO-LIPs demonstrated a superior pharmacokinetic profile relative to free MTO. The first target site of accumulation is the kidney, followed by the liver, and then the tumor; maximal tumor accumulation occurs at 4 h post-administration. Moreover, the LHRH-MTO-LIPs exhibited enhanced inhibition of MCF-7 breast cancer cell growth in vivo compared with non-targeted MTO-loaded liposomes (MTO-LIPs) and free MTO. CONCLUSION: The novel LHRH receptor-targeted liposome may become a viable platform for the future targeted treatment of cancer.

Chitosan hydrochloride/hyaluronic acid nanoparticles coated by mPEG as long-circulating nanocarriers for systemic delivery of mitoxantrone.

The purpose of this study was to prepare and investigate long circulating polyelectrolyte nanoparticles (PENPs) based on hydrochloride chitosan (HCS) and hyaluronic acid (HA) coated by methoxy poly(ethylene glycol) (mPEG). Mitoxantrone hydrochloride (MTO) was selected as a model drug. TEM showed that MTO-loaded PENPs (MTO-PENPs) were spherical but MTO-loaded PENPs coated by mPEG (MTO-mPEG-PENPs) had a slightly rough morphology with an average hydrodynamic diameter around 200-240nm. The EE of MTO-mPEG-PENPs and MTO-PENPs were 99.02% and 98.33%, respectively. DSC thermograms showed MTO existed at the molecular level inside the MTO-mPEG-PENPs. Drug release studies revealed MTO-mPEG-PENPs offered better control over the release of drug than uncoated counterparts. Observations of the pharmacokinetic study reveal that MTO-mPEG-PENPs exhibited significant prolongation in blood circulation of drug compared to MTO-PENPs and MTO solution in rats after intravenous administration. The MRT of MTO increased from 117.83min (MTO solutions) and 162.34min (MTO-PENPs) to 344.42min (MTO-mPEG-PENPs). The AUC of MTO in MTO-mPEG-PENPs increased 2.52-fold and 3.41-fold compared to MTO-PENPs and MTO solution, respectively. In conclusion, mPEG coated PENPs based on HCS/HA could present a workable strategy for long-circulating systemic delivery of drugs.

PEGylated graphene oxide/Fe3O4 nanocomposite: Synthesis, characterization, and evaluation of its performance as de novo drug delivery nanosystem.

This paper describes the development of mitoxantrone-loaded PEGylated graphene oxide/magnetite nanoparticles (PEG-GO/Fe3O4-MTX), and investigation of its preliminary drug delivery performance. For this, the GO was synthesized through oxidizing graphite powder, and subsequently carboxylated using a substitution nucleophilic reaction. The carboxylated GO (GO-COOH) was then conjugated with amine end-caped PEG chains by Steglich esterification. Afterward, GO-PEG/Fe3O4 nanocomposite was synthesized through the anchoring of Fe3O4 nanoparticles onto the surface of GO-PEG during the sonication. The biocompatibility and MTX-loading capacity of the synthesized GO-PEG/Fe3O4 nanocomposite were evaluated. The pH dependent drug release behavior and cytotoxicity effect of the MTX-loaded GO-PEG/Fe3O4 nanocomposite were also studied. According to biocompatibility, pH dependent drug release behavior as well as superior physicochemical and biological characteristics of graphene and magnetite nanoparticles, it is expected that the GO-PEG/Fe3O4 nanocomposite may be applied as de novo drug delivery system (DDS) for cancer therapy using both chemo- and photothermal therapy approaches.

Facile Supramolecular Approach to Nucleic-Acid-Driven Activatable Nanotheranostics That Overcome Drawbacks of Photodynamic Therapy.

Supramolecular chemistry provides a "bottom-up" method to fabricate nanostructures for biomedical applications. Herein, we report a facile strategy to directly assemble a phthalocyanine photosensitizer (PcS) with an anticancer drug mitoxantrone (MA) to form uniform nanostructures (PcS-MA), which not only display nanoscale optical properties but also have the capability of undergoing nucleic-acid-responsive disassembly. These supramolecular assemblies possess activatable fluorescence emission and singlet oxygen generation associated with the formation of free PcS, mild photothermal heating, and a concomitant chemotherapeutic effect associated with the formation of free MA. In vivo evaluations indicate that PcS-MA nanostructures have a high level of accumulation in tumor tissues, are capable of being used for cancer imaging, and have significantly improved anticancer effect compared to that of PcS. This study demonstrates an attractive strategy for overcoming the limitations of photodynamic cancer therapy.

Studies on the adsorption and desorption of mitoxantrone to lauric acid/albumin coated iron oxide nanoparticles.

A rational use of superparamagnetic iron oxide nanoparticles (SPIONs) in drug delivery, diagnostics, and other biomedical applications requires deep understanding of the molecular drug adsorption/desorption mechanisms for proper design of new pharmaceutical formulations. The adsorption and desorption of the cytostatic Mitoxantrone (MTO) to lauric acid-albumin hybrid coated particles SPIONs (SEONLA-HSA) was studied by Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), surface titration, release experiments and small-angle neutron and X-ray scattering. Such MTO-loaded nanoparticles have shown very promising results in in vivo animal models before, while the exact binding mechanism of the drug was unknown. SEONLA-HSA formulations have shown better stability under drug loading in comparison with uncoated nanoparticle and sustainable drug release to compare with protein solution. Adsorption of MTO to SEONLA-HSA leads to decreasing of absolute value of zeta potential and repulsive interaction among particles, which points to the location of separate molecules of MTO on the outer surface of LA-HSA shell.

Synthetic Analogs of Curcumin Modulate the Function of Multidrug Resistance-Linked ATP-Binding Cassette Transporter ABCG2.

Multidrug resistance (MDR) caused by the overexpression of ATP-binding cassette (ABC) transporters in cancer cells is a major obstacle in cancer chemotherapy. Previous studies have shown that curcumin, a natural product and a dietary constituent of turmeric, inhibits the function of MDR-related ABC transporters, including ABCB1, ABCC1, and especially ABCG2. However, the limited bioavailability of curcumin prevents its use for modulation of the function of these transporters in the clinical setting. In this study, we investigated the effects of 24 synthetic curcumin analogs with increased bioavailability on the transport function of ABCG2. The screening of the 24 synthetic analogs by means of flow cytometry revealed that four of the curcumin analogs (GO-Y030, GO-Y078, GO-Y168, and GO-Y172) significantly inhibited the efflux of the ABCG2 substrates, mitoxantrone and pheophorbide A, from ABCG2-overexpressing K562/breast cancer resistance protein (BCRP) cells. Biochemical analyses showed that GO-Y030, GO-Y078, and GO-Y172 stimulated the ATPase activity of ABCG2 at nanomolar concentrations and inhibited the photolabeling of ABCG2 with iodoarylazidoprazosin, suggesting that these analogs interact with the substrate-binding sites of ABCG2. In addition, when used in cytotoxicity assays, GO-Y030 and GO-Y078 were found to improve the sensitivity of the anticancer drug, SN-38, in K562/BCRP cells. Taken together, these results suggest that nontoxic synthetic curcumin analogs with increased bioavailability, especially GO-Y030 and GO-Y078, inhibit the function of ABCG2 by directly interacting at the substrate-binding site. These synthetic curcumin analogs could therefore be developed as potent modulators to overcome ABCG2-mediated MDR in cancer cells.

PLGA nanoparticles introduction into mitoxantrone-loaded ultrasound-responsive liposomes: In vitro and in vivo investigations.

A novel ultrasound-responsive liposomal system for tumor targeting was prepared in order to increase the antitumor efficacy and decrease serious side effects. In this paper, PLGA nanoparticles were used ultrasound-responsive agents instead of conventional microbubbles. The PLGA-nanoparticles were prepared by an emulsion solvent evaporation method. The liposomes were prepared by a lipid film hydration method. Particle size, zeta potential, encapsulation efficiency and drug loading capacity of the liposomes were studied by light scattering analysis and dialysis. Transmission electron microscopy (TEM) and atomic force microscope (AFM) were used to investigate the morphology of liposomes. The release in vitro was carried out in the pH 7.4 phosphate buffer solutions, as a result, liposome L3 encapsulating PLGA-nanoparticles displayed good stability under simulative physiological conditions and quickly responsive release under the ultrasound. The release in vivo was carried out on the rats, as a result, liposome L3 showed higher bioavailability than traditional intravenous injectable administration, and liposome L3 showed higher elimination ratio after stimulation by ultrasound than L3 without stimulation. Thus, the novel ultrasound-responsive liposome encapsulating PLGA-nanoparticles has a potential to be developed as a new drug delivery system for anti-tumor drug.

Surface PEGylation of Mesoporous Silica Nanorods (MSNR): Effect on loading, release, and delivery of mitoxantrone in hypoxic cancer cells.

Mesoporous silica nanomaterials show great potential to deliver chemotherapeutics for cancer treatment. The key challenges in the development of injectable mesoporous silica formulations are colloidal instability, hemolysis and inefficient drug loading and release. In this study, we evaluated the effect of PEGylation of mesoporous silica nanorods (MSNR) on hemolysis, colloidal stability, mitoxantrone (MTX) loading, in vitro MTX release, and cellular MTX delivery under hypoxic conditions. We found that PEGylation prevented dose-dependent hemolysis in the concentrations studied (0-10 mg/ml) and improved colloidal stability of MSNR. A negative effect of PEGylation on MTX loading was observed but PEGylated MSNR (PMSNR) demonstrated increased MTX release compared to non-PEGylated particles. Under hypoxic conditions, a decrease in the IC50 of MTX and MTX-loaded MSNR was observed when compared to normoxic conditions. These results showed that MSNR could deliver the chemotherapeutic agent, MTX to tumor cells and induce effective cell killing. However, the effect of PEGylation needs to be carefully studied due to the observed adverse effect on drug loading.

Exposure-Response Analysis of Alvocidib (Flavopiridol) Treatment by Bolus or Hybrid Administration in Newly Diagnosed or Relapsed/Refractory Acute Leukemia Patients.

Purpose: To elucidate any differences in the exposure-response of alvocidib (flavopiridol) given by 1-hour bolus or a hybrid schedule (30-minute bolus followed by a 4-hour infusion) using a flavopiridol/cytosine arabinoside/mitoxantrone sequential protocol (FLAM) in patients with acute leukemia. The hybrid schedule was devised to be pharmacologically superior in chronic leukemia based on unbound exposure.Experimental Design: Data from 129 patients in three FLAM studies were used for pharmacokinetic/pharmacodynamic modeling. Newly diagnosed (62%) or relapsed/refractory (38%) patients were treated by bolus (43%) or hybrid schedule (57%). Total and unbound flavopiridol concentrations were fit using nonlinear mixed-effect population pharmacokinetic methodologies. Exposure-response relationships using unbound flavopiridol AUC were explored using recursive partitioning.Results: Flavopiridol pharmacokinetic parameters were estimated using a two-compartment model. No pharmacokinetic covariates were identified. Flavopiridol fraction unbound was 10.9% and not different between schedules. Partitioning found no association between dosing schedule and clinical response. Clinical response was associated with AUC ≥ 780 h*ng/mL for newly diagnosed patients and AUC ≥ 1,690 h*ng/mL for relapsed/refractory patients. Higher exposures were not associated with increases in severe adverse events (≥ grade 3).Conclusions: Pharmacokinetic modeling showed no difference in flavopiridol plasma protein binding for bolus versus hybrid dosing. Further trials in newly diagnosed patients with acute leukemia should utilize the bolus FLAM regimen at the MTD of 50 mg/m2/day. Trials in relapsed/refractory patients should use the hybrid dosing schedule at the MTD (30/60 mg/m2/day) to achieve the higher exposures required for maximal efficacy in this population. Clin Cancer Res; 23(14); 3592-600. ©2017 AACR.