Extending Half Life of H-Ferritin Nanoparticle by Fusing Albumin Binding Domain for Doxorubicin Encapsulation

Nanoparticles based on the heavy chain of the human ferritin (HFn) are arousing growing interest in the field of drug delivery due to their exceptional characteristics. However, the unsatisfied plasma half life of HFn substantially limits its application as a delivery platform for antitumor agents. Herein we fused an albumin binding domain (ABD) variant that basically derives from the streptococcal protein G and possesses a long-acting characteristic in serum albumin to the N-terminus of the HFn for the aim of half-life extension. This ABD-HFn construct was highly expressed and fully self-assembled into symmetrical and spherical structure in E. coli bacteria. The purified ABD-HFn showed a similar particle size with wild-type HFn and also exhibited an extremely high binding affinity with human serum albumin. To evaluate the therapeutic potential of this ABD-HFn construct in terms of half-life extension, we encapsulated a model antitumor agent doxorubicin (DOX) into the ABD-HFn. Significantly outstanding loading efficacy of above 60 molecules doxorubicin for each ABD-HFn cage was achieved. The doxorubicin-loaded ABD-HFn nanoparticle was characterized and further compared with the recombinant HFn counterpart. The ABD-HFn/DOX nanoparticle showed dramatically improved stability and comparable cell uptake rate when compared with HFn/DOX counterpart. Pharmacokinetics study in Sprague-Dawley rats showed that ABD-HFn/DOX nanoparticle possessed significantly prolonged plasma half life of ∼17.2 h, exhibiting nearly 19 times longer than that of free doxorubicin and 12 times for HFn/DOX. These optimal results indicated that fusion with ABD will be a promising strategy to extend the half life for protein-based nanoparticles.

Label-free electrochemical immunosensor for ultrasensitive detection of neuron-specific enolase based on enzyme-free catalytic amplification

Enzyme-free catalytic amplification is of great significance for sensitive label-free electrochemical immunosensors. In this study, an enzyme-free catalytic amplification based label-free amperometric immunosensor was developed for sensitive detection of neuron-specific enolase (NSE) by use of a AuPd nanoparticle-multiwalled carbon nanotube (AuPd-MWCNT) composite, ferrocenecarboxaldehyde (Fc-CHO), and chitosan hybrid hydrogel. The intrinsic virtues of chitosan not only resulted in bioactivity of the attached antibodies and made the other component of the immunosensor easier to fix on the electrode, but also imparted abundant binding sites to the hydrogel to condense Fc-CHO to achieve the initial signal amplification. Fc-CHO, which served as an electroactive species to generate a redox response, also exhibits excellent electrocatalytic activity toward H₂O₂. AuPd-MWCNT composite, with enhanced peroxidase-like catalytic activity, could catalyze H₂O₂ to accelerate electron transfer. When H₂O₂ was present in the detection solution, synergetic catalysis of Fc-CHO and AuPd-MWCNT composite toward H₂O₂ was achieved, thus realizing enzyme-free signal amplification. On the basis of this enzyme-free signal amplification, the electrochemical immunosensing platform provided a wide linear range from 1 pg mL^-1 to 100 ng mL^-1, a low detection limit of 0.483 pg mL^-1, and high sensitivity of 7.22 μA (log₁₀ C _NSE)^-1. Moreover, the immunosensor showed enormous potential in clinical application. Graphical abstract An enzyme-free catalytic amplification based label-free amperometric immunosensor was developed for sensitive detection of neuron-specific enolase (NSE) by use of a AuPd nanoparticle-multiwalled carbon nanotube (MWCNT) composite, ferrocenecarboxaldehyde (Fc-CHO), and chitosan (CS) hybrid hydrogel. BSA bovine serum albumin, GA glutaraldehyde, SWV square wave voltammetry.

Phylogenetic and genetic variation analyses of porcine circovirus type 2 isolated from China

Porcine circovirus type 2 (PCV2) is a causative agent of PCV2-associated disease, which is a growing problem in the swine industry worldwide. High nucleotide substitution occurs in the capsid (Cap) gene of PCV2, which allows the continuous evolution and the emergence of novel PCV2 strains. In this study, we sequenced 24 Chinese PCV2 strains collected from healthy and diseased pigs between 2013 and 2015. Analyses of the genome, Cap and phylogeny classified the 24 Chinese PCV2 strains as PCV-2a (four of 24), PCV-2b (five of 24) and PCV-2d (15 of 24). All strains shared 89.5%-100% and 87.2%-100% identities with the nucleotide and amino acid (aa) sequences of Cap, respectively. Selection pressure analysis showed that five sites at the epitope regions in Cap were under positive selection. Further analysis by Jameson-Wolf antigenic index indicated that aa substitutions occurring at the epitope regions contributed to the antigenic alterations of the different PCV2 strains. High genetic variation and genotype shift to PCV2d occurred in recent years, and different genotypes coexisted in Chinese pig herds. The data provide evidence for the increased genetic diversity and insights into the molecular epidemiology of PCV2.

Albumin Binding Domain Fusing R/K-X-X-R/K Sequence for Enhancing Tumor Delivery of Doxorubicin

For the purpose of improving the tumor delivery of doxorubicin (DOX), a kind of peptide-DOXO conjugate was designed and prepared, in which the peptide composed of an albumin-binding domain (ABD) and a tumor-specific internalizing sequence (RGDK or RPARPAR) was conjugated to a (6-maleimidocaproyl) hydrazone derivative of doxorubicin (DOXO-EMCH). The doxorubicin uptake by lung cancer cell line of A549 evidenced that the conjugates are capable of being internalized through a tumor-specific sequence mediated manner, and the intracellular imaging of distribution in A549 cell demonstrated that the conjugated doxorubicin can be delivered to the cell nucleus. The A549 cell cytotoxicity of peptide-DOXO conjugates was presented with IC₅₀ values and shown in the range of about 9-11 μM. Pharmacokinetics study revealed that both conjugates exhibited nearly 5.5 times longer half-time than DOX, and about 4 times than DOXO-EMCH. The in vivo growth inhibitions of the two peptide-DOXO conjugates on BALB/c nude mice bearing A549 tumor (47.78% for ABD-RGDK-DOXO and 47.09% for ABD-RPARPAR-DOXO) were much stronger than that of doxorubicin and DOXO-EMCH (24.28% and 25.67% respectively) at a doxorubicin equivalent dose. Besides, the in vivo fluorescence imaging study confirmed that the peptide markedly increased the payload accumulation in tumor tissues and indicated that albumin binding domain fusing tumor-specific sequence effectively enhanced the tumor delivery of doxorubicin and thus improved its therapeutic potency.

The effect of Echinococcus granulosus on spleen cells and TGF-β expression in the peripheral blood of BALB/c mice

Cystic echinococcosis (CE) caused by the cestode Echinococcus granulosus (E. granulosus) is a zoonotic parasitic disease. The effective immune evasion mechanisms of E. granulosus allow it to parasitize its hosts. However, the status of the innate and adaptive immune cells and their contributions to E. granulosus progression remain poorly understood. In this study, we aimed to determine the impact of E. granulosus infection on T cells, NK cell responses and TGF-β expression during the early infection phase in BALB/c mice. In E. granulosus infections, there was an increasing tendency in the percentage of CD4⁺ CD25⁺ T cells and CD4⁺ Foxp3⁺ T cells and peripheral blood TGF-β levels and relative expression of the Foxp3 gene. Moreover, there were a decreasing tendency in the percentage of NK cells and NK cell cytotoxicity and the expression of NKG2D on NK cells. The TGF-β1/Smad pathway was activated by E. granulosus in mice. Above results can be reversed by the inhibitor SB-525334 (potent activin receptor-like kinase 5 inhibitor). These results suggest that the TGF-β/Smad pathway plays an important role in changes of T-cell or NK cell responses. These results may contribute to revealing the preliminary molecular mechanisms in establishing hydatid infection.

A Rare Case of Two Accessory Maxillae with Bilateral Tessier 7 clefts

A 10-year-old Chinese girl with two accessory maxillae and bilateral Tessier no. 7 clefts is presented. Radiographic examination showed two accessory maxillae, each containing 5 or 6 supernumerary permanent teeth. The two accessory maxillae extended from the inside of the zygomatic arch to the maxillary tuberosity symmetrically. Duplication of the maxilla is always associated with Amniotic Band Syndrome (ABS), but this case may be a distinct syndrome representing an under-recognised phenotype with bilateral maxillae duplication and Tessier no. 7 clefts.

Transcriptome analysis of miRNA-lncRNA-mRNA interactions in the malignant transformation process of gastric cancer initiation

Gastric cancer is a common heterogeneous malignancy that is pathologically characterized by the development of chronic atrophic gastritis and dysplasia of the epithelium. The pathogenic mechanisms at the molecular level are completely unclear. In the present study, we first address the expression network and miRNA-lncRNA-mRNA interaction in the malignant transformation process from normal mucosa and atrophic gastritis to a tumor. First, the long non-coding RNA (lncRNA), micro RNA (miRNA) and messenger RNA (mRNA) expression profiles of normal gastric mucosa, atrophic gastritis, gastric cancer and the peri-tumor tissues were analyzed using microarrays. Then, bioinformatic analyses were used to predict the gene targets and analyse their potential roles in tumorigenesis and progression of gastric cancer. Finally, an intersection analysis of microarray data showed that 10 miRNAs and 11 lncRNAs were detected in the malignant transformation process from normal mucosa tissues and atrophic gastritis to tumorigenesis, and many miRNAs and lncRNAs were novel and had important roles. Meanwhile, the significant pathways and biological functions regulated by the deregulated 21 non-coding genes were enriched. In conclusion, our work provides an important theoretical, experimental and clinical foundation for further research on more effective targets for the diagnosis, therapy and prognosis of gastric cancer.

Two cadmium(II) fluorous coordination compounds tuned by different bipyridines

Fluorine is the most electronegative element and can be used as an excellent hydrogen-bond acceptor. Fluorous coordination compounds exhibit several advantageous properties, such as enhanced high thermal and oxidative stability, low polarity, weak intermolecular interactions and a small surface tension compared to hydrocarbons. C-H...F-C interactions, although weak, play a significant role in regulating the arrangement of the organic molecules in the crystalline state and stabilizing the secondary structure. Two cadmium(II) fluorous coordination compounds formed from 2,2'-bipyridine, 4,4'-bipyridine and pentafluorobenzoate ligands, namely catena-poly[[aqua(2,2'-bipyridine-κ²N,N')(2,3,4,5,6-pentafluorobenzoato-κO)cadmium(II)]-μ-2,3,4,5,6-pentafluorobenzoato-κ²O:O'], [Cd(C₇F₅O₂)₂(C₁₀H₈N₂)(H₂O)]_n, (1), and catena-poly[[diaquabis(2,3,4,5,6-pentafluorobenzoato-κO)cadmium(II)]-μ-4,4'-bipyridine-κ²N:N'], [Cd(C₇F₅O₂)₂(C₁₀H₈N₂)(H₂O)₂]_n, (2), have been synthesized solvothermally and structurally characterized. Compound (1) shows a one-dimensional chain structure composed of Cd-O coordination bonds and is stabilized by π-π stacking and O-H...O hydrogen-bond interactions. Compound (2) displays a one-dimensional linear chain structure formed by Cd-N coordination interactions involving the 4,4'-bipyridine ligand. Adjacent one-dimensional chains are extended into two-dimensional sheets by O-H...O hydrogen bonds between the coordinated water molecules and adjacent carboxylate groups. Moreover, the chains are further linked by C-H...F-C interactions to afford a three-dimensional network. In both structures, hydrogen bonding involving the coordinated water molecules is a primary driving force in the formation of the supramolecular structures.

[Effects of autophagy on lipopolysaccharide-induced vascular hyper-permeability]

OBJECTIVE

To investigate the effects of autophagy on lipopolysaccharide (LPS)-induced vascular hyper-permeability.

METHODS

(1) In vitro: Human umbilical vein endothelial cells (HUVECs) were randomly divided into blank group, LPS group (5 mg/L LPS stimulation), autophagy inhibitor 6-amino-3-methyl purine (3-MA) + LPS group (5 mmol/L 3-MA pretreatment for 30 minutes + 5 mg/L LPS stimulation) and autophagy revulsive Rapamycin (RAP) + LPS group (10 nmol/L RAP pretreatment for 30 minutes + 5 mg/L LPS stimulation). After LPS simulation for 60 minutes in four groups, endothelial permeability was detected by trans-endothelial electrical resistance (TER) determination. The protein expressions of autophagy marker protein microtubule-associated protein 1 light chain 3 (LC3 II/I) and autophagy related gene Beclin-1 were detected by Western Blot. Cell apoptosis was evaluated by using flow cytometry. Caspase-3 activity was detected by fluorometric assay kit. (2) In vivo: 24 Sprague-Dawley (SD) rats were randomly assigned to four groups according to random number table, with 6 rats in each group. The rats in control group received no treatment; rats in model group were tail intravenous injected 10 mg/kg of LPS. The rats in 3-MA pretreatment and RAP pretreatment groups were tail intravenous injected 10 mg/kg of 3-MA or 2 mg/kg of RAP pretreatment for 30 minutes before 10 mg/kg LPS injection. The extravasation of FITC-albumin in mesenteric post-capillary venules was observed by fluorescence microscope. Then the change in fluorescence intensity of FITC-albumin between the intravascular and extravascular space (ΔI) were measured to reflect vascular permeability.

RESULTS

(1) In vitro, compared with blank group, the LC3 II/I protein, Beclin-1 protein, caspase-3 activity and rate of cell apoptosis in LPS group were increased, and the TER was decreased. Compared with LPS group, the LC3 II/I, Beclin-1, caspase-3 activity and rate of cell apoptosis in 3-MA+LPS group were decreased, and the TER was increased [LC3 II/I protein: (288.2±33.3)% vs. (420.5±39.4)%, Beclin-1 protein: (185.3±26.4)% vs. (293.3±36.1)%, caspase-3 activity: (196.6±28.5)% vs. (339.5±25.4)%, rate of cell apoptosis: (9.50±0.99)% vs. (15.40±1.55)%, TER: 0.88±0.09 vs. 0.63±0.05, all P < 0.05]. Compared with LPS group, the LC3 II/I, Beclin-1, caspase-3 activity and rate of cell apoptosis in RAP+LPS group were further increased, and the TER was further decreased [LC3 II/I protein: (519.6±45.2)% vs. (420.5±39.4)%, Beclin-1 protein: (359.0±38.3)% vs. (293.3±36.1)%, caspase-3 activity: (449.1±31.0)% vs. (339.5±25.4)%, rate of cell apoptosis: (19.30±1.72)% vs. (15.40±1.55)%, TER: 0.54±0.05 vs. 0.63±0.05, all P < 0.05]. (2) In vivo, the albumin extravasation and vascular permeability were increased in model group as compared with those of control group (ΔI: 0.54±0.07 vs. 0.13±0.03, P < 0.05). The albumin extravasation and vascular permeability were obviously decreased in 3-MA pretreatment group as compared with those of model group (ΔI: 0.25±0.05 vs. 0.54±0.07, P < 0.05). The albumin extravasation and vascular permeability were obviously increased in RAP pretreatment group as compared with those of model group (ΔI: 0.67±0.07 vs. 0.54±0.07, P < 0.05).

CONCLUSIONS

Inhibition of autophagy can reduce the LPS-induced vascular hyper-permeability, and enhanced autophagy can further increase vascular permeability. The mechanism of autophagy mediate vascular permeability may be related to the endothelial cells apoptosis.

Exploring the structure and photodissociation mechanism of the electronic states of iodocarbene, CHI: a theoretical contribution

Interactions between the electronic states of CHI were investigated and the dissociation mechanism was explored in the ultraviolet region.

Extracorporeal Membrane Oxygenation (ECMO) for Severe Toxicological Exposures: Review of the Toxicology Investigators Consortium (ToxIC)

Although there have been many developments related to specific strategies for treating patients after poisoning exposures, the mainstay of therapy remains symptomatic and supportive care. One of the most aggressive supportive modalities is extracorporeal membrane oxygenation (ECMO). Our goal was to describe the use of ECMO for toxicological exposures reported to the American College of Medical Toxicology (ACMT) Toxicology Investigators Consortium (ToxIC). We performed a retrospective review of the ACMT ToxIC Registry from January 1, 2010 to December 31, 2013. Inclusion criteria included patients aged 0 to 89 years, evaluated between January 2010 through December 2013, and received ECMO for toxicological exposure. There were 26,271 exposures (60 % female) reported to the ToxIC Registry, 10 (0.0004 %) received ECMO: 4 pediatric (< 12 years), 2 adolescent (12-18 years), and 4 adults (>18 years). Time of initiation of ECMO ranged from 4 h to 4 days, with duration from 15 h to 12 days. Exposures included carbon monoxide/smoke inhalation (2), bitter almonds, methanol, and several medications including antihistamines (2), antipsychotic/antidepressant (2), cardiovascular drugs (2), analgesics (2), sedative/hypnotics (2), and antidiabetics (2). Four ECMO patients received cardiopulmonary resuscitation (CPR) during their hospital course, and the overall survival rate was 80 %. ECMO was rarely used for poisoning exposures in the ACMT ToxIC Registry. ECMO was utilized for a variety of ages and for pharmaceutical and non-pharmaceutical exposures. In most cases, ECMO was administered prior to cardiovascular failure, and survival rate was high. If available, ECMO may be a valid treatment modality.

Toxic effect of NiCl2 on development of the bursa of Fabricius in broiler chickens

This study was conducted with objective of evaluating the toxic effects of nickel chloride (NiCl₂) on development of bursa of Fabricius in broilers fed on diets supplemented with 0, 300, 600 and 900 mg/kg of NiCl₂ for 42 days by using the methods of experimental pathology, flow cytometry (FCM), and quantitative real-time polymerase chain reaction (qRT-PCR). The results showed that dietary NiCl₂ in 300 mg/kg and over induced toxic suppression in the bursal development, which was characterized by decreasing lymphocytes histopathologically and relative weight, increasing G₀/G₁ phase (a prolonged nondividing state), reducing S phase (DNA replication) and proliferating index, and increasing percentages of apoptotic cells. Concurrently, the mRNA expression levels of bax, cytochrome c (cyt c), apoptotic peptidase activating factor 1 (Apaf-1), caspase-3, caspase-6, caspase-7 and caspase-9 were increased and the bcl-2 mRNA expression levels were decreased. The toxic suppression of bursal development finally impaired humoral immunity duo to the reduction of B lymphocyte population and B lymphocyte activity in the broiler chicken. This study provides new evidences for further studying the effect mechanism of Ni and Ni compoundson B-cell or bursa of Fabricius.

The detection accuracy of cone beam CT for osseous defects of the temporomandibular joint: a systematic review and meta-analysis

The purpose of this review was to evaluate whether cone-beam computed tomography (CBCT) is reliable for the detection of bone changes of the temporomandibular joint (TMJ). Studies collected from the PubMed, Web of Science, Cochrane Library, ScienceDirect, Embase, Wanfang and CNKI databases were searched, and the publishing time was limited from January 1990 to December 2015. Eight studies (23 experimental research groups) were eventually included for further analysis. The pooled sensitivity was 0.67 and the pooled specificity was 0.87, which leads to a relatively large area (0.84) under the Receiver Operating Characteristic (ROC) curve. The related pooled positive likelihood ratio (+LR) and the pooled negative likelihood ratio (−LR) were 5.2 and 0.38, respectively. The subgroup analysis was conducted for four subgroups categorized by voxel size (≤0.2; >0.2, ≤0.3; >0.3, ≤0.4; >0.4, and ≤0.5 (mm)), and the “>0.4, ≤0.5” subgroup had a higher pooled sensitivity and pooled specificity than the other groups. The present study demonstrates that CBCT has a relatively high diagnostic accuracy for TMJ bone changes, although its reliability is limited. Voxel size did not play a role in the accuracy of CBCT.

Nickel Chloride (NiCl2) Induces Histopathological Lesions via Oxidative Damage in the Broiler's Bursa of Fabricius

The purpose of this study was to investigate the histopathological lesions, oxidative damage, changes of immunoglobulin G (IgG), immunoglobulin M (IgM), and immunoglobulin A (IgA) contents in the bursa of Fabricius and serum immunoglobulins (IgG, IgM, IgA) induced by dietary nickel chloride (NiCl2). Two hundred and eighty-one-day-old broilers were randomly divided into four groups and fed on a control diet and three experimental diets supplemented with 300, 600, and 900 mg/kg of NiCl2 for 42 days. Lesions were observed in the NiCl2-treated groups. Histopathologically, lymphocytes were decreased in lymphoid follicles with thinner cortices and wider medullae. Concurrently, the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and the ability to inhibit hydroxyl radical and glutathione (GSH) contents were significantly (p < 0.05 or p < 0.01) decreased, while malondialdehyde (MDA) contents were increased in the NiCl2-treated groups. The serum IgG, IgM, and bursa IgG and IgM contents were significantly (p < 0.05 or p < 0.01) lower in the NiCl2-treated groups than those in the control group. The above-mentioned results show that dietary NiCl2 in excess of 300 mg/kg can cause histopathological lesions via oxidative damage, which finally impairs the function of the bursa of Fabricius and reduces IgG and IgM contents of the serum and the bursa of Fabricius. The study is aimed to provide helpful materials for studies on Ni- or Ni compounds-induced B cell toxicity in both human and other animals in the future.

Role of the IL-11/STAT3 signaling pathway in human chronic atrophic gastritis and gastric cancer

The expression of interleukin-11 (IL-11) and its products STAT3 and phospho-STAT3 (p-STAT3) in patients with chronic superficial gastritis (CSG), chronic atrophic gastritis (CAG), and gastric cancer (GC) may provide insight into the diagnostic role of the IL-11/STAT3 signaling pathway in GC. Gastric mucosa specimens and serum samples were collected from 90 patients with CSG, CAG, and GC (30/group). The expression of IL-11, STAT3, and p-STAT3 was detected via immunohistochemistry and western blot. Additionally, serum levels of IL-11 were measured by enzyme-linked immunosorbent assay. For IL-11, 60% stained positive in CAG and 83.3% stained positive in GC, which were both higher than the value observed for CSG (33.3%). Moreover, the percent positive for IL-11 in GC was higher than that in CAG (P < 0.05). The percent positive for STAT3 in CAG (80%) and GC (83.3%) was higher than that in CSG (53.3%) (P < 0.05). Compared with CSG (36.7%), the percent positive for p-STAT3 in CAG (63.3%) and GC (86.7%) was also significantly higher. STAT3 expression was similar in GC and CAG, which was significantly higher than that in CSG. Expectedly, p-STAT3 expression gradually increased from CSG to CAG to GC. Furthermore, p-STAT3 levels were higher in GC tissues than in CAG (P < 0.01). Intriguingly, serum IL-11 levels gradually increased from CSG to CAG to GC, which coincided with disease severity. Together, these results suggest that the IL-11/STAT3 signaling pathway plays a critical role in human CAG, and may provide new targets to prevent and treat GC.