A novel phosphodiesterase inhibitor for the treatment of chronic liver injury and metabolic diseases.

BACKGROUND AND AIMS: Chronic liver disease (CLD) leads to approximately two million deaths annually. Cyclic adenosine monophosphate (cAMP) signaling has long been studied in liver injury, particularly in the regulation of fatty acid (FA) ß-oxidation and pro-inflammatory polarization of tissue-resident lymphocytes. Phosphodiesterase 4B (PDE4B) inhibition has been explored as a therapeutic modality, but these drugs have had limited success and are known to cause significant adverse effects. The PDE4 inhibitor 2-(4-([2-(5-Chlorothiophen-2-yl)-5-ethyl-6-methylpyrimidin-4-yl]amino)phenyl)acetic acid) (known as A-33) has yet to be explored for the treatment of metabolic diseases. APPROACH AND RESULTS: Herein, we evaluated the efficacy of A-33 in the treatment of animal models of alcohol-associated liver disease (ALD) and steatotic liver disease (SLD). We demonstrated that A-33 effectively ameliorated the signs and symptoms of CLD, resulting in significant decreases in serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, decreased overall fat and collagen deposition in the liver, decreased intrahepatic triglyceride (TG) concentrations, and normalized expression of genes related to ß-oxidation of fatty acids, inflammation, and extracellular matrix (ECM) deposition. We also designed and synthesized a novel analog of A-33, termed MDL3, which inhibited both PDE4B and PDE5A and was more effective in ameliorating pathophysiological signs and symptoms of liver injury and inflammation. In addition, MDL3 re-sensitized obese mice to glucose and significantly inhibited the pathological remodeling of adipose tissue, which was not observed with A-33 administration. CONCLUSIONS: In conclusion, we synthesized and demonstrated that MDL3, a novel PDE4B and PDE5A inhibitor, presents a promising avenue of exploration for treating CLD.

Recent Advances in DNA Nanotechnology-Based Sensing Platforms for Rapid Virus Detection.

Several major viral pandemics in history have significantly impacted the public health of human beings. The COVID-19 pandemic has further underscored the critical need for early detection and screening of infected individuals. However, current detection techniques are confronted with deficiencies in sensitivity and accuracy, restricting the capability of detecting trace amounts of viruses in human bodies and in the environments.The advent of DNA nanotechnology has opened up a feasible solution for rapid and sensitive virus determination. By harnessing the designability and addressability of DNA nanostructures, a range of rapid virus sensing platforms have been proposed. This review overviewed the recent progress, application, and prospect of DNA nanotechnology-based rapid virus detection platforms. Furthermore, the challenges and developmental prospects in this field were discussed.

Quality Control of Mass-Encoded Nanodevices by Compartmented DNA Origami Frames for Precision Information Coding and Logic Mapping.

Encoded nanostructures afford an ideal platform carrying multi-channel signal components for multiplexed assay and information security. However, with the demand on exclusivity and reproducibility of coding signals, precise control on the structure and composition of nanomaterials featuring fully distinguishable signals remains challenging. By using the multiplexing capability of mass spectrometry (MS) and spatial addressability of DNA origami nanostructures, we herein propose a quality control methodology for constructing mass-encoded nanodevices (namely MNTs-TDOFs) in the scaffold of compartmented tetrahedral DNA origami frames (TDOFs), in which the arrangement and stoichiometry of four types of mass nanotags (MNTs) can be finely regulated and customized to generate characteristic MS patterns. The programmability of combinatorial MNTs and orthogonality of individual compartments allows further evolution of MNTs-TDOFs to static tagging agents and dynamic nanoprobes for labeling and sensing of multiple targets. More importantly, structure control at single TDOF level ensures the constancy of prescribed MS outputs, by which a high-capacity coding system was established for secure information encryption and decryption. In addition to the multiplexed outputs in parallel, the nanodevices could also map logic circuits with interconnected complexity and logic events of c-Met recognition and dimerization on cell surface for signaling regulation by MS interrogation.

Confinement in Dual-Chain-Locked DNA Origami Nanocages Programs Marker-Responsive Delivery of CRISPR/Cas9 Ribonucleoproteins.

Delivery of CRISPR/Cas9 ribonucleoproteins (RNPs) offers a powerful tool for therapeutic genome editing. However, precise manipulation of CRISPR/Cas9 RNPs to switch the machinery on and off according to diverse disease microenvironments remains challenging. Here, we present dual-chain-locked DNA origami nanocages (DL-DONCs) that can confine Cas9 RNPs in the inner cavity for efficient cargo delivery and dual-marker-responsive genome editing in the specified pathological states. By engineering of ATP or miRNA-21-responsive dsDNAs as chain locks on the DONCs, the permeability of nanocages and accessibility of encapsulated Cas9 RNPs can be finely regulated. The resulting DL-DONCs enabled steric protection of bioactive Cas9 RNPs from premature release and deactivation during transportation while dismounting the dual chain locks in response to molecular triggers after internalization into tumor cells, facilitating the escape of Cas9 RNPs from the confinement for gene editing. Due to the dual-marker-dominated uncaging mechanism, the gene editing efficiency could be exclusively determined by the combined level of ATP and miRNA-21 in the target cellular environment. By targeting the tumor-associated PLK-1 gene, the DL-DONCs-enveloped Cas9 RNPs have demonstrated superior inhibitory effects on the proliferation of tumor cells in vitro and in vivo. The developed DL-DONCs provide a custom-made platform for the precise manipulation of Cas9 RNPs, which can be potentially applied to on-demand gene editing for classified therapy in response to arbitrary disease-associated biomolecules.

Two-Stage Assembly of Nanoparticle Superlattices with Multiscale Organization.

Self-assembly processes, while promising for enabling the fabrication of complexly organized nanomaterials from nanoparticles, are often limited in creating structures with multiscale order. These limitations are due to difficulties in practically realizing the assembly processes required to achieve such complex organizations. For a long time, a hierarchical assembly attracted interest as a potentially powerful approach. However, due to the experimental limitations, intermediate-level structures are often heterogeneous in composition and structure, which significantly impacts the formation of large-scale organizations. Here, we introduce a two-stage assembly strategy: DNA origami frames scaffold a coordination of nanoparticles into designed 3D nanoclusters, and then these clusters are assembled into ordered lattices whose types are determined by the clusters' valence. Through modulating the nanocluster architectures and intercluster bindings, we demonstrate the successful formation of complexly organized nanoparticle crystals. The presented two-stage assembly method provides a powerful fabrication strategy for creating nanoparticle superlattices with prescribed unit cells.

Antischistosomal tetrahydro-γ-carboline sulfonamides.

We discovered tetrahydro-γ-carboline sulfonamides as a new antischistosomal chemotype. The aryl sulfonamide and tetrahydro-γ-carboline substructures were required for high antischistosomal activity. Increasing polarity improved solubility and metabolic stability but decreased antischistosomal activity. We identified two compounds with IC50 values <5 µM against ex vivo Schistosoma mansoni.

Identification and development of an independent immune-related genes prognostic model for breast cancer.

BACKGROUND: Breast cancer is one of the main malignant tumors that threaten the lives of women, which has received more and more clinical attention worldwide. There are increasing evidences showing that the immune micro-environment of breast cancer (BC) seriously affects the clinical outcome. This study aims to explore the role of tumor immune genes in the prognosis of BC patients and construct an immune-related genes prognostic index. METHODS: The list of 2498 immune genes was obtained from ImmPort database. In addition, gene expression data and clinical characteristics data of BC patients were also obtained from the TCGA database. The prognostic correlation of the differential genes was analyzed through Survival package. Cox regression analysis was performed to analyze the prognostic effect of immune genes. According to the regression coefficients of prognostic immune genes in regression analysis, an immune risk scores model was established. Gene set enrichment analysis (GSEA) was performed to probe the biological correlation of immune gene scores. P < 0.05 was considered to be statistically significant. RESULTS: In total, 556 immune genes were differentially expressed between normal tissues and BC tissues (p < 0. 05). According to the univariate cox regression analysis, a total of 66 immune genes were statistically significant for survival risk, of which 30 were associated with overall survival (P < 0.05). Finally, a 15 immune genes risk scores model was established. All patients were divided into high- and low-groups. KM survival analysis revealed that high immune risk scores represented worse survival (p < 0.001). ROC curve indicated that the immune genes risk scores model had a good reliability in predicting prognosis (5-year OS, AUC = 0.752). The established risk model showed splendid AUC value in the validation dataset (3-year over survival (OS) AUC = 0.685, 5-year OS AUC = 0.717, P = 0.00048). Moreover, the immune risk signature was proved to be an independent prognostic factor for BC patients. Finally, it was found that 15 immune genes and risk scores had significant clinical correlations, and were involved in a variety of carcinogenic pathways. CONCLUSION: In conclusion, our study provides a new perspective for the expression of immune genes in BC. The constructed model has potential value for the prognostic prediction of BC patients and may provide some references for the clinical precision immunotherapy of patients.

Adapting and Remolding: Orchestrating Tumor Microenvironment Normalization with Photodynamic Therapy by Size Transformable Nanoframeworks.

Abnormal tumor microenvironment (TME) facilitates tumor proliferation and metastasis and establishes physiological barriers for effective transport of therapeutics inside the tumor, posing great challenges for cancer treatment. We designed a core-satellite size transformable nanoframework (denoted as T-PFRT) that can synchronously adapt to and remold TME for augmenting photodynamic therapy to inhibit tumor growth and prevent tumor metastasis. Upon matrix metalloproteinase 2 (MMP2)-responsive dissociation of the nanoframework in TME, the core structure loaded with TGFß signaling pathway inhibitor and oxygen-carrying hemoglobin aims to stroma remodeling and hypoxia relief, allowing photosensitizer-encapsulated satellite particles to penetrate to deep-seated tumor for oxygen-fueled photodynamic therapy. T-PFRT could overcome the stroma and hypoxia barriers for delivering therapeutics and gain excellent therapeutic outcomes in the treatment of primary and metastatic tumors.

Efficacy, metabolism and pharmacokinetics of Ro 15-5458, a forgotten schistosomicidal 9-acridanone hydrazone.

BACKGROUND: Treatment of schistosomiasis, a neglected disease, relies on just one partially effective drug, praziquantel. We revisited the 9-acridanone hydrazone, Ro 15-5458, a largely forgotten antischistosomal lead compound. METHODS: Ro 15-5458 was evaluated in juvenile and adult Schistosoma mansoni-infected mice. We studied dose-response, hepatic shift and stage specificity. The metabolic stability of Ro 15-5458 was measured in the presence of human and mouse liver microsomes, and human hepatocytes; the latter also served to identify metabolites. Pharmacokinetic parameters were measured in naive mice. The efficacy of Ro 15-5458 was also assessed in S. haematobium-infected hamsters and S. japonicum-infected mice. RESULTS: Ro 15-5458 had single-dose ED50 values of 15 and 5.3 mg/kg in mice harbouring juvenile and adult S. mansoni infections, respectively. An ED50 value of 17 mg/kg was measured in S. haematobium-infected hamsters; however, the compound was inactive at up to 100 mg/kg in S. japonicum-infected mice. The drug-induced hepatic shift occurred between 48 and 66 h post treatment. A single oral dose of 50 mg/kg of Ro 15-5458 had high activity against all tested S. mansoni stages (1-, 7-, 14-, 21- and 49-day-old). In vitro, human hepatocytes produced N-desethyl and glucuronide metabolites; otherwise Ro 15-5458 was metabolically stable in the presence of microsomes or whole hepatocytes. The maximum plasma concentration was approximately 8.13 µg/mL 3 h after a 50 mg/kg oral dose and the half-life was approximately 4.9 h. CONCLUSIONS: Ro 15-5458 has high activity against S. mansoni and S. haematobium, yet lacks activity against S. japonicum, which is striking. This will require further investigation, as a broad-spectrum antischistosomal drug is desirable.

Tricyclic Imidazolidin-4-ones by Witkop Oxidation of Tetrahydro-ß-carbolines.

1-Substituted and 1,1-disubstituted tetrahydro-ß-carbolines undergo sodium periodate oxidative ring expansion in the presence of formaldehyde and other aldehydes to form 5,6-dihydro-7H-1,4-methanobenzo[e][1,4]diazonine-2,7(3H)-diones in 30-81% yield. In most cases, the reaction to form this new 6/8/5-tricyclic ring system proceeds with high diastereoselectivity. These benzannulated medium-ring keto imidazolidin-4-ones expand the menu of tetrahydro-ß-carboline oxidation products.

Design of Hedgehog pathway inhibitors for cancer treatment.

Hedgehog (Hh) signaling is involved in the initiation and progression of various cancers and is essential for embryonic and postnatal development. This pathway remains in the quiescent state in adult tissues but gets activated upon inflammation and injuries. Inhibition of Hh signaling pathway using natural and synthetic compounds has provided an attractive approach for treating cancer and inflammatory diseases. While the majority of Hh pathway inhibitors target the transmembrane protein Smoothened (SMO), some small molecules that target the signaling cascade downstream of SMO are of particular interest. Substantial efforts are being made to develop new molecules targeting various components of the Hh signaling pathway. Here, we have discussed the discovery of small molecules as Hh inhibitors from the diverse chemical background. Also, some of the recently identified natural products have been included as a separate section. Extensive structure-activity relationship (SAR) of each chemical class is the focus of this review. Also, clinically advanced molecules are discussed from the last 5 to 7 years. Nanomedicine-based delivery approaches for Hh pathway inhibitors are also discussed concisely.

Polymeric Micellar Delivery of Novel Microtubule Destabilizer and Hedgehog Signaling Inhibitor for Treating Chemoresistant Prostate Cancer.

Castration-resistant prostate cancer that has become resistant to docetaxel (DTX) represents one of the greatest clinical challenges in the management of this malignancy. There is an urgent need to develop novel therapeutic agents to overcome chemoresistance and improve the overall survival of patients. We have designed a novel microtubule destabilizer (2-(4-hydroxy-1H-indol-3-yl)-1H-imidazol-4-yl)(3,4,5-trimethoxyphenyl)methanone (QW-296) and combined it with a newly synthesized hedgehog (Hh) signaling pathway inhibitor 2-chloro-N 1-[4-chloro-3-(2-pyridinyl)phenyl]-N 4,N 4- bis(2-pyridinylmethyl)-1,4-benzenedicarboxamide (MDB5) to treat taxane-resistant (TXR) prostate cancer. The combination of QW-296 and MDB5 exhibited stronger anticancer activity toward DU145-TXR and PC3-TXR cells and suppressed tumor colony formation when compared with single-drug treatment. Because these drugs are hydrophobic, we synthesized the mPEG-p(TMC-MBC) [methoxy-poly(ethylene glycol)-block-poly(trimethylene carbonate-co-2-methyl-2-benzoxycarbonyl-propylene carbonate)] copolymer, which could self-assemble into micelles with loading capacities of 8.13% ± 0.75% and 9.12% ± 0.69% for QW-296 and MDB5, respectively. Further, these micelles provided controlled the respective drug release of 58% and 42% release of QW-296 and MDB5 within 24 hours when dialyzed against PBS (pH 7.4). We established an orthotopic prostate tumor in nude mice using stably luciferase expressing PC3-TXR cells. There was maximum tumor growth inhibition in the group treated with the combination therapy of QW-296 and MDB5 in micelles compared with their monotherapies or combination therapy formulated in cosolvent. The overall findings suggest that combination therapy with QW-296 and MDB5 has great clinical potential to treat TXR prostate cancer, and copolymer mPEG-p(TMC-MBC) could serve as an effective delivery vehicle to boost therapeutic efficacy in vivo.

Immuno-Electrochemiluminescent Imaging of a Single Cell Based on Functional Nanoprobes of Heterogeneous Ru(bpy)32+@SiO2/Au Nanoparticles.

It is valuable to develop a sensing platform for not only detecting a tumor marker in body fluids but also measuring its expression at single cells. In the present study, a simple closed bipolar electrodes-based electrochemiluminescence (BPEs-ECL) imaging strategy was developed for visual immunoassay of prostate specific antigen (PSA) at single cells using functional nanoprobes of heterogeneous Ru(bpy)32+@SiO2/Au nanoparticles. Multiple-assisted ECL signal amplification strategy was introduced into the detection system on the basis of the synergetic amplifying effect of the anodic and cathodic amplification. On the basis of the synergetic amplifying effect, the detection limits of PSA by using photomultiplier tube and charge-coupled device (CCD) imaging are 3.0 and 31 pg/mL, respectively. The obtained immunosensor was employed to evaluate PSA levels in serum samples with a satisfying result. Moreover, the obtained functional nanoprobes were used to visually profile the PSA expression on the surface of single LNCaP cells (a kind of prostate cancer cells) based on a bare BPE. The results show that the functional nanoprobes-based ECL imaging immunoassay provides a promising visual platform for detecting tumor markers (proteins and cancer cells) and thus shows a high potential in cancer diagnosis.

SAR of a new antischistosomal urea carboxylic acid.

Urea carboxylic acids, products of aryl hydantoin hydrolysis, were recently identified as a new antischistosomal chemotype. We now describe a baseline structure-activity relationship (SAR) for this compound series. With one exception, analogs of lead urea carboxylic acid 2 were quite polar with Log D7.4 values ranging from -1.9 to 1.8, had high aqueous solubilities in the range of 25-100 µg/mL, and were metabolically stable. None of the compounds had measurable in vitro antischistosomal activity or cytotoxicity, but four of these had moderate worm burden reduction (WBR) values of 42-70% when they were administered as single 100 mg/kg oral doses to S. mansoni-infected mice. These data indicate that with the exception of the gem-dimethyl substructure and the distal nitrogen atom of the urea functional group, the rest of the structure of 2 is required for in vivo antischistosomal activity.

Progress in antischistosomal N,N'-diaryl urea SAR.

N,N'-Diaryl ureas have recently emerged as a new antischistosomal chemotype. We now describe physicochemical profiling, in vitro ADME, plasma exposure, and ex vivo and in vivo activities against Schistosoma mansoni for twenty new N,N'-diaryl ureas designed primarily to increase aqueous solubility, but also to maximize structural diversity. Replacement of one of the 4-fluoro-3-trifluoromethylphenyl substructures of lead N,N'-diaryl urea 1 with azaheterocycles and benzoic acids, benzamides, or benzonitriles decreased lipophilicity, and in most cases, increased aqueous solubility. There was no clear relationship between lipophilicity and metabolic stability, although all compounds with 3-trifluoromethyl-4-pyridyl substructures were metabolically stable. N,N'-diaryl ureas containing 4-fluoro-3-trifluoromethylphenyl, 3-trifluoromethyl-4-pyridyl, 2,2-difluorobenzodioxole, or 4-benzonitrile substructures had high activity against ex vivo S. mansoni and relatively low cytotoxicity. N,N-diaryl ureas with 3-trifluoromethyl-4-pyridyl and 2,2-difluorobenzodioxole substructures had the highest exposures whereas those with 4-fluoro-3-trifluoromethylphenyl substructures had the best in vivo antischistosomal activities. There was no direct correlation between compound exposure and in vivo activity.

Small molecule mimics of DFTamP1, a database designed anti-Staphylococcal peptide.

Antimicrobial peptides (AMPs) are important templates for developing new antimicrobial agents. Previously, we developed a database filtering technology that enabled us to design a potent anti-Staphylococcal peptide DFTamP1. Using this same design approach, we now report the discovery of a new class of bis-indole diimidazolines as AMP small molecule mimics. The best compound killed multiple S. aureus clinical strains in both planktonic and biofilm forms. The compound appeared to target bacterial membranes with antimicrobial activity and membrane permeation ability similar to daptomycin.

Treatment of a chemoresistant neuroblastoma cell line with the antimalarial ozonide OZ513.

BACKGROUND: Evaluate the anti-tumor activity of ozonide antimalarials using a chemoresistant neuroblastoma cell line, BE (2)-c. METHODS: The activity of 12 ozonides, artemisinin, and two semisynthetic artemisinins were tested for activity against two neuroblastoma cell-lines (BE (2)-c and IMR-32) and the Ewing's Sarcoma cell line A673 in an MTT viability assay. Time course data indicated that peak effect was seen 18 h after the start of treatment thus 18 h pre-treatment was used for all subsequent experiments. The most active ozonide (OZ513) was assessed in a propidium iodide cell cycle flow cytometry analysis which measured cell cycle transit and apoptosis. Metabolic effects of OZ513 in BE (2)-c cells was evaluated. Western blots for the apoptotic proteins cleaved capase-3 and cleaved PARP, the highly amplified oncogene MYCN, and the cell cycle regulator CyclinD1, were performed. These in-vitro experiments were followed by an in-vivo experiment in which NOD-scid gamma immunodeficient mice were injected subcutaneously with 1 × 106 BE (2)-c cells followed by immediate treatment with 50-100 mg/kg/day doses of OZ513 administered IP three times per week out to 23 days after injection of tumor. Incidence of tumor development, time to tumor development, and rate of tumor growth were assessed in DMSO treated controls (N = 6), and OZ513 treated mice (N = 5). RESULTS: It was confirmed that five commonly used chemotherapy drugs had no cytotoxic activity in BE (2)-c cells. Six of 12 ozonides tested were active in-vitro at concentrations achievable in vivo with OZ513 being most active (IC50 = 0.5 mcg/ml). OZ513 activity was confirmed in IMR-32 and A673 cells. The Ao peak on cell-cycle analysis was increased after treatment with OZ513 in a concentration dependent fashion which when coupled with results from western blot analysis which showed an increase in cleaved capase-3 and cleaved PARP supported an increase in apoptosis. There was a concentration dependent decline in the MYCN and a cyclinD1 protein indicative of anti-proliferative activity and cell cycle disruption. OXPHOS metabolism was unaffected by OZ513 treatment while glycolysis was increased. There was a significant delay in time to tumor development in mice treated with OZ513 and a decline in the rate of tumor growth. CONCLUSIONS: The antimalarial ozonide OZ513 has effective in-vitro and in-vivo activity against a pleiotropic drug resistant neuroblastoma cell-line. Treatment with OZ513 increased apoptotic markers and glycolysis with a decline in the MYCN oncogene and the cell cycle regulator cyclinD1. These effects suggest adaptation to cellular stress by mechanism which remain unclear.

Aryl hydantoin Ro 13-3978, a broad-spectrum antischistosomal.

OBJECTIVES: Praziquantel is the only drug available for the treatment of schistosomiasis and the state of the exhausted drug discovery pipeline is alarming. We restarted investigations on the abandoned antischistosomal Ro 13-3978, an aryl hydantoin discovered in the early 1980s by Hoffmann La-Roche. METHODS: Newly transformed schistosomula and adult Schistosoma mansoni were studied in the presence of Ro 13-3978 in vitro. The metabolic stability of Ro 13-3978 was determined in vitro using human and mouse liver S9 fractions. Dose-response relationship, stage specificity, hepatic shift and scanning electron microscopy studies were carried out in S. mansoni-infected mice. In addition, efficacy experiments were conducted in rodents infected with Echinostoma caproni and Fasciola hepatica as well as in S. mansoni-infected immunocompromised nude (Foxn1(nu)) mice. RESULTS: Ro 13-3978 showed minor in vitro activity and no damage to the tegument was found. No cytotoxicity was detected for Ro 13-3978. Ro 13-3978 was metabolically stable. ED50 values of 138.9 and 14.6 mg/kg were calculated for the treatment of juvenile and adult S. mansoni infections, respectively, with a single oral dose of Ro 13-3978. SEM studies revealed severe damage to the worms 48 h post-treatment of infected mice. A single oral dose of Ro 13-3978 (100 mg/kg) administered to S. mansoni-infected (Foxn1(nu)) mice reduced the worm burden by 88%. Ro 13-3978 was not active against E. caproni and F. hepatica in vivo. CONCLUSIONS: Ro 13-3978 has excellent antischistosomal properties in vivo. Structure-activity relationship studies with the aryl hydantoins have been launched in order to elucidate active pharmacophores, further investigate the mechanism of action and to identify a derivative with minimal antiandrogenic effects.

Synthesis and Characterization of a Novel Mycophenolic Acid-Quinic Acid Conjugate Serving as Immunosuppressant with Decreased Toxicity.

Mycophenolic acid (MPA) is one of the most commonly used immunosuppressive drugs for improving the outcome of cell and organ transplantations. However, an undesired adverse effect of MPA impedes its application in the clinics for post-transplant patients. By conjugating MPA to quinic acid (QA) via amide bonds, we synthesized a novel immunosuppressant, N-[2-[[(4E)-6-(1,3-dihydro-4-hydroxy-6-methoxy-7-methyl-3-oxo-5-isobenzofuranyl)-4-methyl-1-oxo-4-hexen-1-yl]amino]ethyl]-(1α,3R,4α,5R)-1,3,4,5-tetrakis(acetyloxy)cyclohexanecarboxamide (abbreviated as MQ4), which exhibits improved stability demonstrated by its incubation in vitro with human plasma, suggesting its better resistance to hydrolytic degradation induced by plasma enzyme. While the immunosuppressive effect of MQ4 on human lymphocyte proliferation was partially compromised as shown by flow cytometry, significant decrease in cytotoxicity of MQ4 to insulin producing ß cells could compensate this drawback to some degree. There was a decreased level of apoptotic mediator caspase-3, which may contribute to the decreased toxicity of MQ4 to INS-1E cells. MQ4 could further improve insulin stimulation index and downregulate NFκB expression compared to physical mixing of QA to MPA. Taken together, MQ4 is a promising immunosuppressive agent for preventing and minimizing post-transplanted immune rejection.

Peripherally cross-linking the shell of core-shell polymer micelles decreases premature release of physically loaded combretastatin A4 in whole blood and increases its mean residence time and subsequent potency against primary murine breast tumors after IV administration.

PURPOSE: Determine the feasibility and potential benefit of peripherally cross-linking the shell of core-shell polymer micelles on the premature release of physically loaded hydrophobic drug in whole blood and subsequent potency against solid tumors. METHODS: Individual Pluronic F127 polymer micelles (F127 PM) peripherally cross-linked with ethylenediamine at 76% of total PEO blocks (X-F127 PM) were physically loaded with combretastatin A4 (CA4) by the solid dispersion method and compared to CA4 physically loaded in uncross-linked F127 PM, CA4 in DMSO in vitro, or water-soluble CA4 phosphate (CA4P) in vivo. RESULTS: X-F127 PM had similar CA4 loading and aqueous solubility as F127 PM up to 10 mg CA4 / mL at 22.9 wt% and did not aggregate in PBS or 90% (v/v) human serum at 37°C for at least 24 h. In contrast, X-F127 PM decreased the unbound fraction of CA4 in whole blood (fu) and increased the mean plasma residence time and subsequent potency of CA4 against the vascular function and growth of primary murine 4T1 breast tumors over CA4 in F127 PM and water-soluble CA4P after IV administration. CONCLUSIONS: Given that decreasing the fu is an indication of decreased drug release, peripherally cross-linking the shell of core-shell polymer micelles may be a simple approach to decrease premature release of physically loaded hydrophobic drug in the blood and increase subsequent potency in solid tumors.