Regulation of Erythroid Differentiation via the HIF1α-NFIL3-PIM1 Signaling Axis Under Hypoxia.

Aims: Erythropoiesis is controlled by several factors, including oxygen level under different circumstances. However, the role of hypoxia in erythroid differentiation and the underlying mechanisms are poorly understood. We studied the effect and mechanism of hypoxia on erythroid differentiation of K562 cells and observed the effect of hypoxia on early erythropoiesis of zebrafish. Results: Compared with normal oxygen culture, both hemin-induced erythroid differentiation of K562 cells and the early erythropoiesis of zebrafish were inhibited under hypoxic treatment conditions. Hypoxia-inducible factor 1 alpha (HIF1α) plays a major role in the response to hypoxia. Here, we obtained a stable HIF1α knockout K562 cell line using the CRISPR-Cas9 technology and further demonstrated that HIF1α knockout promoted hemin-induced erythroid differentiation of K562 cells under hypoxia. We demonstrated an HIF1-mediated induction of the nuclear factor interleukin-3 (NFIL3) regulated in K562 cells under hypoxia. Interestingly, a gradual decrease in NFIL3 expression was detected during erythroid differentiation of erythropoietin-induced CD34+ hematopoietic stem/progenitor cells (HSPCs) and hemin-induced K562 cells. Notably, erythroid differentiation was inhibited by enforced expression of NFIL3 under normoxia and was promoted by the knockdown of NFIL3 under hypoxia in hemin-treated K562 cells. In addition, a target of NFIL3, pim-1 proto-oncogene, serine/threonine kinase (PIM1), was obtained by RNA microarray after NFIL3 knockdown. PIM1 can rescue the inhibitory effect of NFIL3 on hemin-induced erythroid differentiation of K562 cells. Innovation and Conclusion: Our findings demonstrate that the HIF1α-NFIL3-PIM1 signaling axis plays an important role in erythroid differentiation under hypoxia. These results will provide useful clues for preventing the damage of acute hypoxia to erythropoiesis.

Reducing cherry rain-cracking: Enhanced wetting and barrier properties of chitosan hydrochloride-based coating with dual nanoparticles.

The synergistic effects of phosphorylated zein nanoparticles (PZNP) and cellulose nanocrystals (CNC) in enhancing the wetting and barrier properties of chitosan hydrochloride (CHC)-based coating are investigated characterized by Fourier Transform Infrared Spectra (FTIR), X-ray Diffraction (XRD), atomic force microscopy and by investigating the mechanical properties, etc., with the aim of reducing cherry rain cracking. FTIR and XRD showed dual nanoparticles successfully implanted into CHC, CHC-PZNP-CNC combined moderate ductility (elongation at break: 7.8 %), maximum tensile strength (37.5 MPa). The addition of PZNP alone significantly improved wetting performance (Surface Tension, CHC: 55.3 vs. CHC-PZNP: 48.9 mN/m), while the addition of CNC alone led to a notable improvement in the water barrier properties of CHC (water vapor permeability, CHC: 6.75 × 10-10 vs. CHC-CNC: 5.76 × 10-10 gm-1 Pa-1 s-1). The final CHC-PZNP-CNC coating exhibited enhanced wettability (51.2 mN/m) and the strongest water-barrier property (5.32 × 10-10 gm-1 Pa-1 s-1), coupled with heightened surface hydrophobicity (water contact angle: 106.4°). Field testing demonstrated the efficacy of the CHC-PZNP-CNC coating in reducing cherry rain-cracking (Cracking Index, Control, 42.3 % vs. CHC-PZNP-CNC, 19.7 %; Cracking Ratio, Control, 34.6 % vs. CHC-PZNP-CNC, 15.8 %). The CHC-PZNP-CNC coating is a reliable option for preventing rain-induced cherry cracking.

Construction and characterization of Zn-WPH-COS complex nanoparticles with improved zinc bioavailability.

Precipitation was an important obstacle to improving zinc's bioavailability. Therefore, zinc-whey protein hydrolysate-chitosan oligosaccharide (Zn-WPH-COS) complexes (167 nm) were prepared by linking Zn-WPH (zinc: 18.4%) with COS (1:1, 2 h) to enhance zinc's bioaccessibility. Fourier-transform infrared showed Zn-WPH formed with zinc replaced hydrogen (from 3274 to 3279 cm-1) and reacted with COO- (C-N: from 1394 to 1402 cm-1), a new peak at 1025 cm-1 proved COS can be successful cross-linked (Zn-WPH-COS). Fluorescence spectra showed zinc and COS reduced WPH hydrophobicity (28.0 and 39.0%, respectively). Circular dichroism showed zinc decreased WPH α-helix (from 13.7 to 11.5%), in contrast with COS to Zn-WPH. Zinc solubility and dialyzability were increased (64.5/ 54.2% vs 50.2/ 41.2% vs 29.5/ 21.7%) in Zn-WPH-COS, compared with Zn-WPH and ZnSO4·7H2O, respectively, due to the smallest size (167 nm) and COS protection on Zn-WPH (gastric digestion). These results indicate Zn-WPH-COS could significantly improve the digestion and absorption of zinc.

Influence of postdiagnostic aspirin use on clinical outcomes of women with breast cancer: a meta-analysis.

We examined the association between postdiagnostic aspirin use and recurrence and disease-specific mortality among women with breast cancer in a meta-analysis. The PubMed, Embase, and Web of Science databases were searched to identify observational studies with longitudinal follow-ups according to the aim of the meta-analysis. Combining the results was achieved using a random-effects model that included inter-study heterogeneity. Fifteen cohort studies with 131,636 women with breast cancer were included. Based on a meta-analysis, women who took aspirin after being diagnosed with breast cancer had a lower risk of breast cancer recurrence (adjusted risk ratio [RR]: 0.77, 95 percent confidence interval [CI]: 0.63 to 0.95, P = .02; I2 = 72 percent) and breast cancer specific mortality (adjusted RR: 0.73, 95 percent CI: 0.60 to 0.90, P = .004; I2 = 80 percent) than those who did not use aspirin. The certainty of the evidence was rated using the Grading of Recommendations Assessment, Development, and Evaluations scoring system showed moderate certainty for both the outcomes because significant inconsistency was observed. In conclusion, aspirin use after diagnosis might be associated with reduced recurrence and disease-specific mortality in women with breast cancer.

Influence of environmental pH on the interaction properties of WP-EGCG non-covalent nanocomplexes.

BACKGROUND: Whey protein-epigallocatechin gallate (WP-EGCG) covalent conjugates and non-covalent nanocomplexes were prepared and compared using Fourier-transform infrared spectra. The effect of pH (at 2.6, 6.2, 7.1, and 8.2) on the non-covalent nanocomplexes' functional properties and the WP-EGCG interactions were investigated by studying antioxidant activity, emulsification, fluorescence quenching, and molecular docking, respectively. RESULTS: With the formation of non-covalent and covalent complexes, the amide band decreased; the -OH peak disappeared; the antioxidant activity of WP-EGCG non-covalent complexes was 2.59- and 2.61-times stronger than WP-EGCG covalent conjugates for 1-diphenyl-2-picryl-hydrazyl (DPPH) and ferric reducing ability of plasma (FRAP), respectively (particle size: 137 versus 370 nm). The antioxidant activity (DPPH 27.48-44.32%, FRAP 0.47-0.63) was stronger at pH 6.2-7.1 than at pH 2.6 and pH 8.2 (DPPH 19.50% and 26.36%, FRAP 0.39 and 0.41). Emulsification was highest (emulsifying activity index 181 m2 g-1 , emulsifying stability index 107%) at pH 7.1. The interaction between whey protein (WP) and EGCG was stronger under neutral and weakly acidic conditions: KSV (5.11-8.95 × 102 L mol-1 ) and Kq (5.11-8.95 × 1010 L mol s-1 ) at pH 6.2-7.1. Binding constants (pH 6.2 and pH 7.1) increased with increasing temperature. Molecular docking suggested that hydrophobic interactions played key roles at pH 6.2 and pH 7.1 (∆H > 0, ∆S > 0). Hydrogen bonding was the dominant force at pH 2.6 and pH 8.2 (∆H < 0, ∆S < 0). CONCLUSION: Environmental pH impacted the binding forces of WP-EGCG nanocomplexes. The interaction between WP and EGCG was stronger under neutral and weakly acidic conditions. Neutral and weakly acidic conditions are preferable for WP-EGCG non-covalent nanocomplex formation. © 2023 Society of Chemical Industry.

TRAF3IP3 Is Cleaved by EV71 3C Protease and Exhibits Antiviral Activity.

Enterovirus 71 (EV71) is one of the major pathogens of hand, foot, and mouth disease, which poses a major risk to public health and infant safety. 3C protease (3Cpro), a non-structural protein of EV71, promotes viral protein maturation by cleaving polyprotein precursors and facilitates viral immune escape by cleaving host proteins. In this study, we screened for human proteins that could interact with EV71 3Cpro using a yeast two-hybrid assay. Immune-associated protein TRAF3 Interacting Protein 3 (TRAF3IP3) was selected for further study. The results of co-immunoprecipitation and immunofluorescence demonstrated the interaction between TRAF3IP3 and EV71 3Cpro. A cleavage band was detected, indicating that both transfected 3Cpro and EV71 infection could cleave TRAF3IP3. 87Q-88G was identified as the only 3Cpro cleavage site in TRAF3IP3. In Jurkat and rhabdomyosarcoma (RD) cells, TRAF3IP3 inhibited EV71 replication, and 3Cpro cleavage partially resisted TRAF3IP3-induced inhibition. Additionally, the nuclear localization signal (NLS) and nuclear export signal (NES) of TRAF3IP3 were identified. The NES contributed to TRAF3IP3 alteration of 3Cpro localization and inhibition of EV71 replication. Together, these results indicate that TRAF3IP3 inhibits EV71 replication and 3Cpro resists such inhibition via proteolytic cleavage, providing a new example of virus-host interaction.

Enterovirus 71 Activates GADD34 via Precursor 3CD to Promote IRES-Mediated Viral Translation.

Enterovirus 71 (EV71) is the major pathogen of hand, foot, and mouth disease. In severe cases, it can cause life-threatening neurological complications, such as aseptic meningitis and polio-like paralysis. There are no specific antiviral treatments for EV71 infections. In a previous study, the host protein growth arrest and DNA damage-inducible protein 34 (GADD34) expression was upregulated during EV71 infection determined by ribosome profiling and RNA-sequencing. Here, we investigated the interactions of host protein GADD34 and EV71 during infections. Rhabdomyosarcoma (RD) cells were infected with EV71 resulting in a significant increase in expression of GADD34 mRNA and protein. Through screening of EV71 protein we determined that the non-structural precursor protein 3CD is responsible for upregulating GADD34. EV71 3CD increased the RNA and protein levels of GADD34, while the 3CD mutant Y441S could not. 3CD upregulated GADD34 translation via the upstream open reading frame (uORF) of GADD34 5'untranslated regions (UTR). EV71 replication was attenuated by the knockdown of GADD34. The function of GADD34 to dephosphorylate eIF2α was unrelated to the upregulation of EV71 replication, but the PEST 1, 2, and 3 regions of GADD34 were required. GADD34 promoted the EV71 internal ribosome entry site (IRES) activity through the PEST repeats and affected several other viruses. Finally, GADD34 amino acids 563 to 565 interacted with 3CD, assisting GADD34 to target the EV71 IRES. Our research reveals a new mechanism by which GADD34 promotes viral IRES and how the EV71 non-structural precursor protein 3CD regulates host protein expression to support viral replication. IMPORTANCE Identification of host factors involved in viral replication is an important approach in discovering viral pathogenic mechanisms and identifying potential therapeutic targets. Previously, we screened host proteins that were upregulated by EV71 infection. Here, we report the interaction between the upregulated host protein GADD34 and EV71. EV71 non-structural precursor protein 3CD activates the RNA and protein expression of GADD34. Our study reveals that 3CD regulates the uORF of the 5'-UTR to increase GADD34 translation, providing a new explanation for how viral proteins regulate host protein expression. GADD34 is important for EV71 replication, and the key functional domains of GADD34 that promote EV71 are PEST 1, 2, and 3 regions. We report that GADD34 promotes viral IRES for the first time and this process is independent of its eIF2α phosphatase activity.

Factors Influencing Luciferase-Based Bioluminescent Imaging in Preclinical Models of Brain Tumor.

Bioluminescent imaging (BLI) is a powerful tool in biomedical research to measure gene expression and tumor growth. The current study examined factors that influence the BLI signal, specifically focusing on the tissue distribution of two luciferase substrates, D-luciferin and CycLuc1. D-luciferin, a natural substrate of firefly luciferase, has been reported to have limited brain distribution, possibly due to the efflux transporter, breast cancer resistance protein (Bcrp), at the blood-brain barrier. CycLuc1, a synthetic analog of D-luciferin, has a greater BLI signal at lower doses than D-luciferin, especially in the brain. Our results indicate that limited brain distribution of D-luciferin and CycLuc1 is predominantly dictated by their low intrinsic permeability across the cell membrane, where the efflux transporter, Bcrp, plays a relatively minor role. Both genetic ablation and pharmacological inhibition of Bcrp decreased the systemic clearance of both luciferase substrates, significantly increasing exposure in the blood and, hence, in organs and tissues. These data also indicate that the biodistribution of luciferase substrates can be differentially influenced in luciferase-bearing tissues, leading to a "tissue-dependent" BLI signal. The results of this study point to the need to consider multiple mechanisms that influence the distribution of luciferase substrates. SIGNIFICANCE STATEMENT: Bioluminescence is used to monitor many biological processes, including tumor growth. This study examined the pharmacokinetics, brain distribution, and the role of active efflux transporters on the luciferase substrates D-luciferin and CycLuc1. CycLuc1 has a more sustained systemic circulation time (longer half-life) that can provide an advantage for the superior imaging outcome of CycLuc1 over D-luciferin. The disparity in imaging intensities between brain and peripheral sites is due to low intrinsic permeability of these luciferase substrates across the blood-brain barrier.

A composite chitosan derivative nanoparticle to stabilize a W1/O/W2 emulsion: Preparation and characterization.

For preparing stable water-in-oil-in-water emulsion, the role of nanoparticles in stabilizing the interface is very important. In this study, chitosan hydrochloride-carboxymethyl chitosan (CHC-CMC) nanoparticles were prepared considering electrostatic interactions; then the emulsion was prepared and the stability characteristics in presence of NaCl (0-200 mmol/L) and 30 d storage were studied. CHC-CMC nanoparticles (261 nm) were obtained when the CHC: CMC ratio was 1:2. CHC-CMC formation was verified by FT-IR when a new peak appeared at 1580 cm-1; W2 contained 2 wt % CHC-CMC and W1 contained 1 wt % sodium alginate, the creaming index (81.6 %) was higher for the emulsions than Tween 80 (67.4 %) after 30 d. Confocal laser scanning microscopy confirmed the double microstructures, in contrast to the collapse with Tween 80, because the CHC-CMC nanoparticles were densely adsorbing on the oil-water interface. This indicates that CHC-CMC has a stronger ability to stabilize W1/O/W2 emulsion than Tween 80.

Identification of tumorigenicity-associated genes in osteosarcoma cell lines based on bioinformatic analysis and experimental validation.

Osteosarcoma is the most common primary malignant tumor of bone. Tumorigenic investigation of osteosarcoma cell lines may facilitate preclinical studies of targeted therapy. Therefore, the aim of this study was to explore the tumorigenicity-associated genes in osteosarcoma cells. We found that 138 genes were highly expressed and 86 genes were lowly expressed in highly tumorigenic osteosarcoma cell lines (143B, MNNG/HOS, and SJSA-1) compared with poorly tumorigenic osteosarcoma cell lines (MG-63, Saos-2, and U-2 OS). Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that highly expressed genes were associated with amino acids and energy metabolism, while lowly expressed genes were associated with cell cycle and DNA replication. Gene Ontology (GO) analysis showed that highly expressed genes were associated with endoplasmic reticulum stress response and aggrephagy, whereas lowly expressed genes were correlated with extracellular matrix assembly and DNA damage response. Further analysis identified six highly expressed genes and six lowly expressed genes. Three of highly expressed genes (DDX10, FOXA2, and HEY1) were correlated with poor prognosis, while three of lowly expressed genes (CYP26B1, GP1BB, and IFI44) showed the opposite trend in patients with osteosarcoma. Knockdown of HEY1 significantly inhibited the tumorigenicity of 143B cells in BALB/c nude mice.

An Enhanced Stability Nanoparticle Preparation by Corn Protein Hydrolysate-Carboxymethyl Chitosan Maillard Conjugates Loaded with Rutin.

Rutin-loaded corn protein hydrolysate-carboxymethyl chitosan (CPH-NOCC) Maillard conjugate nanoparticles (NPs) with superior stability under different NaCl concentrations (0-0.25 mol/L) and pH levels (7.0 to 3.0) were investigated. Results showed that the degree of glycosylation of 53.3%, browning index of 0.6, and SDS-PAGE lane of CPH-NOCC conjugates were obtained after dry heating for 48 hr (60 °C, 79% RH). The high encapsulation efficiency (EE, 97.8%-98.8%) and CPH-NOCC-rutin (98.8%) was significantly higher than CPH-rutin (97.8%) and CPH/NOCC-rutin (98.4%) NPs illustrated that hydrolysis was positive for zein encapsulation, and conjugation of NOCC to CPH increased the EE. Hairy carbohydrate protrusions on the surface of CPH-NOCC-rutin NPs produced a stronger steric effect and hampered the formation of salt bridges and the particle aggregation under CPH isoelectric point at pH 4.0. Therefore, the CPH-NOCC conjugate NPs may be suitable carrier for hydrophobic bioactive substances in a board range of business foodstuffs.

Efficacy of the MDM2 Inhibitor SAR405838 in Glioblastoma Is Limited by Poor Distribution Across the Blood-Brain Barrier.

Controversy exists surrounding whether heterogeneous disruption of the blood-brain barrier (BBB), as seen in glioblastoma (GBM), leads to adequate drug delivery sufficient for efficacy in GBM. This question is especially important when using potent, targeted agents that have a poor penetration across an intact BBB. Efficacy of the murine double minute-2 (MDM2) inhibitor SAR405838 was tested in patient-derived xenograft (PDX) models of GBM. In vitro efficacy of SAR405838 was evaluated in PDX models with varying MDM2 expression and those with high (GBM108) and low (GBM102) expression were evaluated for flank and orthotopic efficacy. BBB permeability, evaluated using TexasRed-3 kDa dextran, was significantly increased in GBM108 through VEGFA overexpression. Drug delivery, MRI, and orthotopic survival were compared between BBB-intact (GBM108-vector) and BBB-disrupted (GBM108-VEGFA) models. MDM2-amplified PDX lines with high MDM2 expression were sensitive to SAR405838 in comparison with MDM2 control lines in both in vitro and heterotopic models. In contrast with profound efficacy observed in flank xenografts, SAR405838 was ineffective in orthotopic tumors. Although both GBM108-vector and GBM108-VEGFA readily imaged on MRI following gadolinium contrast administration, GBM108-VEGFA tumors had a significantly enhanced drug and gadolinium accumulation, as determined by MALDI-MSI. Enhanced drug delivery in GBM108-VEGFA translated into a marked improvement in orthotopic efficacy. This study clearly shows that limited drug distribution across a partially intact BBB may limit the efficacy of targeted agents in GBM. Brain penetration of targeted agents is a critical consideration in any precision medicine strategy for GBM. Mol Cancer Ther; 17(9); 1893-901. ©2018 AACR.

Preparation, characterisation and antioxidant activities of rutin-loaded zein-sodium caseinate nanoparticles.

Novel rutin-loaded zein-sodium caseinate nanoparticles (ZP) with antioxidant activity in aqueous medium were investigated. The results showed that the sodium caseinate concentrations, dosages of rutin and ethanol volume fractions significantly affected the zein nanoparticles' characteristics. Concerning the antioxidant properties, the highest values of rutin loaded ZP obtained using 2, 2-diphenyl-1-picrylhydrazyl scavenging and 2 and 2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) decolourisation assays were 52.7% and 71.2%, respectively, and the total antioxidant capacity was 0.40 nmol g-1. The results suggest that zein-sodium caseinate nanoparticles can be used as a new nano carrier system for rutin or other water insoluble active ingredients.

Enhanced dispersion stability and heavy metal ion adsorption capability of oxidized starch nanoparticles.

Starch nanoparticles (SNPs) have attracted much research interest recently due to their biodegradability and biocompatibility. However, practical utilization of SNPs is generally restricted due to their weak colloid stability and reduced functionality. In this work, SNPs were functionally modified by sodium hypochlorite (1-5% active chlorine based on dry SNPs weight). The degree of modification, particle size, stability, and adsorption characteristics of the SNPs were systematically investigated. The results showed that as the active chlorine concentration increased, the carbonyl and carboxyl contents increased to 0.150% and 0.855%, respectively. Compared with SNPs, the zeta potential value of SNPs modified with 5% active chlorine increased significantly (p<0.05) from -13 to -31mV and the dispersion stability of modified SNPs was remarkably improved. Moreover, modified SNPs exhibited high adsorption capacities for Pb2+ and Cu2+, suggesting that they could be employed as a novel absorbent for removal of heavy metal ions.

Preparation of extra-small nisin nanoparticles for enhanced antibacterial activity after autoclave treatment.

Nisin is applied broadly in the food industry as an antimicrobial peptide. The objective of this study is to prepare nisin nanoparticles using free nisin by a facile nanoprecipitation technique and to investigate their antimicrobial activity after high-temperature processing. Transmission electron microscopic images showed that the size of extra-small nisin nanoparticles with different initial concentrations of nisin (0.1%, 0.3% and 0.5%) was 5, 10 and 15 nm, respectively. The nisin nanoparticles were stable at pH 5.0 with the smallest size. Moreover, nisin nanoparticles exhibited a higher antimicrobial activity than free nisin at a concentration below 2.0 mg/ml after autoclave treatment. These results suggested that nisin nanoparticles could serve as a potential food preservative.

Development of chitosan-sodium phytate nanoparticles as a potent antibacterial agent.

Chitosan nanoparticles have attracted considerable attention as a potential carrier for food and pharmaceutical applications. Herein, using natural sodium phytate as a gelation agent, we developed a new type of green and biocompatible chitosan nanoparticles. We discovered that the chitosan-sodium phytate nanoparticles exhibited potent antibacterial activities. The chitosan-sodium phytate nanoparticles prepared from low molecular weight (LMW, 140±7kDa) and medium molecular weight (MMW, 454±21kDa) chitosan were spherical. Under optimum conditions-with a ratio of LMW chitosan to sodium phytate of 24:1 and MMW chitosan to sodium phytate of 21:1-the sizes of the LMW and MMW chitosan nanoparticles were 20-80 and 80-100nm, respectively, as observed by transmission electron microscopy. The formation mechanism of chitosan nanoparticles occurred through both electrostatic interactions and hydrogen bonds. No cytotoxicity for normal liver cells was found in chitosan-sodium phytate nanoparticles measured by methyl thiazolyl tetrazolium assay. Furthermore, the antimicrobial assays indicated that the antimicrobial activity of the LMW chitosan nanoparticles was greater than that of MMW chitosan nanoparticles. The minimum inhibition concentration values and half inhibiting concentration of LMW chitosan-sodium phytate nanoparticles for Escherichia coli were 1.5 and 0.8mg/mL, respectively. In addition, the antimicrobial activity of chitosan nanoparticles against Gram-negative bacteria was better than that against Gram-positive bacteria. The newly developed chitosan-sodium phytate nanoparticles could be used as a potential antibacterial agent.

Heterogeneous Binding and Central Nervous System Distribution of the Multitargeted Kinase Inhibitor Ponatinib Restrict Orthotopic Efficacy in a Patient-Derived Xenograft Model of Glioblastoma.

This study investigated how differences in drug distribution and free fraction at different tumor and tissue sites influence the efficacy of the multikinase inhibitor ponatinib in a patient-derived xenograft model of glioblastoma (GBM). Efficacy studies in GBM6 flank (heterotopic) and intracranial (orthotopic) models showed that ponatinib is effective in the flank but not in the intracranial model, despite a relatively high brain-to-plasma ratio. In vitro binding studies indicated that flank tumor had a higher free (unbound) drug fraction than normal brain. The total and free drug concentrations, along with the tissue-to-plasma ratio (Kp) and its unbound derivative (Kp,uu), were consistently higher in the flank tumor than the normal brain at 1 and 6 hours after a single dose in GBM6 flank xenografts. In the orthotopic xenografts, the intracranial tumor core displayed higher Kp and Kp,uu values compared with the brain-around-tumor (BAT). The free fractions and the total drug concentrations, hence free drug concentrations, were consistently higher in the core than in the BAT at 1 and 6 hours postdose. The delivery disadvantages in the brain and BAT were further evidenced by the low total drug concentrations in these areas that did not consistently exceed the in vitro cytotoxic concentration (IC50). Taken together, the regional differences in free drug exposure across the intracranial tumor may be responsible for compromising efficacy of ponatinib in orthotopic GBM6.

Morphology and Structural Properties of Novel Short Linear Glucan/Protein Hybrid Nanoparticles and Their Influence on the Rheological Properties of Starch Gel.

Starch nanoparticles were potential texture modifiers. However, they have strong tendency to aggregate and poor water dispersibility, which limited their application. The interaction between glucan (prepared from starch by enzymatic modification) and protein could significantly improve the dispersity of starch nanoparticles and, thus, enhance the rheological properties of food gels. In this work, glucan/protein hybrid nanoparticles were successfully developed for the first time using short linear glucan (SLG) and edible proteins [soy protein isolate (SPI), rice protein (RP), and whey protein isolate (WPI)]. The results showed that the SLG/SPI hybrid nanoparticles exhibited hollow structures, of which the smallest size was approximately 10-20 nm when the SLG/SPI ratio was 10:5. In contrast, SLG/RP nanoparticles displayed flower-like superstructures, and SLG/WPI nanoparticles presented stacked lamellar nanostructures with a width of 5-10 nm and a length of 50-70 nm. In comparison to bare SLG nanoparticles, SLG/SPI and SLG/WPI hybrid nanoparticles had higher melting temperatures. The addition of all nanoparticles greatly increased the storage modulus of corn starch gels and decreased loss tangent values. Importantly, the G' value of starch gels increased by 567% with the addition of flower-like SLG/RP superstructures.

Fabrication and characterization of hollow starch nanoparticles by gelation process for drug delivery application.

Hollow nanoparticles (HNPs) have been widely regarded as controlled drug carriers owing to their advantages, such as high drug-loading efficiency and superior control over drug delivery and release. In this study, a facile and efficient strategy has been exploited for preparation of hollow starch nanoparticles (HSNPs) via a sacrificial hard-template process using gelled starch as the shell. These nanocapsules have been characterized through various techniques, including transmission electron microscopy, differential scanning calorimetry, X-ray diffraction, and Fourier transform infrared spectroscopy. The HSNPs have diameters ranging from 30nm to 300nm, with shell thickness of 5-10nm. X-ray diffraction analysis has revealed that HSNPs exhibit B+V type diffraction peaks with a relative crystallinity of 34.2%. Doxorubicin hydrochloride (DOX·HCl) was readily encased in the nanocarriers with a high loading efficiency (97.56%) and a high loading content (37.12%). In addition, no cytotoxicity for normal liver cells was found in HSNPs. However, DOX·HCl-loaded HSNPs exhibited clear cytotoxicity for liver hepatocellular cells. Thus, the hollow starch nanoparticles form a highly promising platform for cancer therapy.

Semi-rational engineering of a thermostable aldo-keto reductase from Thermotoga maritima for synthesis of enantiopure ethyl-2-hydroxy-4-phenylbutyrate (EHPB).

A novel aldo-keto reductase Tm1743 characterized from Thermotoga maritima was explored as an effective biocatalyst in chiral alcohol production. Natural Tm1743 catalyzes asymmetric reduction of ethyl 2-oxo-4-phenylbutyrate (EOPB) at high efficiency, but the production of, ethyl (S)-2-hydroxy-4-phenylbutyrate ((S)-EHPB), which is less desirable, is preferred with an enantiomeric excess (ee) value of 76.5%. Thus, altering the enantioselectivity of Tm1743 to obtain the more valuable product (R)-EHPB for angiotensin drug synthesis is highly desired. In this work, we determined the crystal structure of Tm1743 in complex with its cofactor NADP+ at 2.0 Å resolution, and investigated the enantioselectivity of Tm1743 through semi-rational enzyme design. Molecular simulations based on the crystal structure obtained two binding models representing the pro-S and pro-R conformations of EOPB. Saturation mutagenesis studies revealed that Trp21 and Trp86 play important roles in determining the enantioselectivity of Tm1743. The best (R)- and (S)-EHPB preferring Tm1743 mutants, denoted as W21S/W86E and W21L/W118H, were identified; their ee values are 99.4% and 99.6% and the catalytic efficiencies are 0.81 and 0.12 mM-1s-1, respectively. Our work presents an efficient strategy to improve the enantioselectivity of a natural biocatalyst, which will serve as a guide for further exploration of new green catalysts for asymmetric reactions.