Recombinant TAT–gelonin fusion toxin: Synthesis and characterization of heparin/protamine‐regulated cell transduction

Protein toxins, such as gelonin, are highly desirable anti‐cancer drug candidates due to their unparalleled potency and repetitive reaction mechanism in inhibiting protein translation. However, for its potential application in cancer therapy, there remains the cell membrane barrier that allows permeation of only small molecules, which must be overcome. To address this challenge, we conjugated gelonin with a protein transduction domain (PTD), the TAT peptide, via genetic recombination. The chimeric TAT–gelonin fusion protein (TAT‐Gel) retained equipotent N ‐glycosidase activity yet displayed greater cell uptake than unmodified recombinant gelonin (rGel), thereby yielding a significantly augmented cytotoxic activity. Remarkably, TAT‐Gel displayed up to 177‐fold lower IC 50 (avg. 54.3 n M ) than rGel (avg. IC 50 : 3640 n M ) in tested cell lines. This enhanced cytotoxicity, however, also raised potential toxicity concerns due to the non‐selectivity of PTD in its mediated cell transduction. To solve this problem, we investigated the plausibility of regulating the cell transduction of TAT‐Gel via a reversible masking using heparin and protamine. Here, we demonstrated, both in vitro and in vivo , that the cell transduction of TAT‐Gel can be completely curbed with heparin and yet this heparin block can be efficiently reversed by the addition of protamine. This reversible tight regulation of the cell transduction of TAT‐Gel by heparin and protamine sheds light of possible application of TAT‐Gel in achieving a highly effective yet safe drug therapy for the treatment of tumors. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 103A: 409–419, 2015.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109572/1/jbma35188.pd

Protease‐Activatable Hybrid Nanoprobe for Tumor Imaging

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108698/1/adfm201400419.pd

Prevalence and Prognostic Significance of HPV in Laryngeal Squamous Cell Carcinoma in Northeast China

Background/Aims: Human papillomavirus (HPV) is an etiological risk factor for a subset of head and neck squamous cell carcinomas. HPV has been proven to be a powerful prognostic biomarker for oropharyngeal cancer, but its role in the larynx has not been explored in depth. Here, we sought to evaluate the prevalence and genotype distribution of HPV in patients with laryngeal squamous cell carcinoma (LSCC) in northeast China. Methods: HPV DNA in specimens from 211 patients diagnosed with LSCC was analyzed by the polymerase chain reaction and in situ hybridization, and p16 overexpression was evaluated by immunohistochemistry. p16 expression was scored positive if strong and diffuse nuclear and cytoplasmic staining was present in > 75% of tumor cells. Results: In this study, infection with HPV and p16 expression were not absolutely consistent. Among all patients, 132 (62.6%) were positive for HPV DNA (HPV+), while 23 (10.9%) were inconsistent for HPV and p16. Multivariate analysis indicated that HPV, but not p16, is an independent prognostic factor for overall survival in LSCC. Overall survival was significantly improved in HPV+ LSCC patients compared with the HPV-negative group (hazard ratio, 0.395; 95% confidence interval, 0.185–0.843; p = 0.016). Among the 132 HPV+ patients, 28 (21.2%) were HPV-16 single infection. Conclusion: This study indicates that HPV DNA is a more reliable surrogate marker than p16 for the prediction of survival in patients with LSCC

Cerebrospinal fluid oligoclonal bands in Chinese patients with multiple sclerosis: the prevalence and its association with clinical features

BackgroundCerebrospinal fluid oligoclonal band (CSF-OCB) is an established biomarker in diagnosing multiple sclerosis (MS), however, there are no nationwide data on CSF-OCB prevalence and its diagnostic performance in Chinese MS patients, especially in the virtue of common standard operation procedure (SOP).MethodsWith a consensus SOP and the same isoelectric focusing system, we conducted a nationwide multi-center study on OCB status in consecutively, and recruited 483 MS patients and 880 non-MS patients, including neuro-inflammatory diseases (NID, n = 595) and non-inflammatory neurological diseases (NIND, n=285). Using a standardized case report form (CRF) to collect the clinical, radiological, immunological, and CSF data, we explored the association of CSF-OCB positivity with patient characters and the diagnostic performance of CSF-OCB in Chinese MS patients. Prospective source data collection, and retrospective data acquisition and statistical data analysis were used.Findings369 (76.4%) MS patients were OCB-positive, while 109 NID patients (18.3%) and 6 NIND patients (2.1%) were OCB-positive, respectively. Time from symptom onset to diagnosis was significantly shorter in OCB-positive than that in OCB-negative MS patients (13.2 vs 23.7 months, P=0.020). The prevalence of CSF-OCB in Chinese MS patients was significantly higher in high-latitude regions (41°-50°N)(P=0.016), and at high altitudes (>1000m)(P=0.025). The diagnostic performance of CSF-OCB differentiating MS from non-MS patients yielded a sensitivity of 76%, a specificity of 87%.InterpretationThe nationwide prevalence of CSF-OCB was 76.4% in Chinese MS patients, and demonstrated a good diagnostic performance in differentiating MS from other CNS diseases. The CSF-OCB prevalence showed a correlation with high latitude and altitude in Chinese MS patients

β-Cyclodextrin Grafted Cellulose and Cationic Starch for Antibacterial Paper Products: A Comparative Study

Two kinds of macromolecules applied in papermaking were modified with β-cyclodextrin (β-CD) and loaded with ciprofloxacin hydrochloride (CipHCl) in an attempt to compare their potential applications in antimicrobial paper. β-CD grafted cellulose (β-CD-Cel) and β-CD grafted cationic starch (β-CD-CS) were prepared by grafting β-CD onto cellulose fiber and cationic starch using citric acid (CA) and epichlorohydrin (ECH) as crosslinking agents, respectively. β-CD-Cel and β-CD-CS were both loaded with an antimicrobial agent (CipHCl) to form inclusion complexes, namely β-CD-Cel-CipHCl and β-CD-CS-CipHCl. Furthermore, the inclusion complexes were added to the pulp to prepare antibacterial paper. The antimicrobial activity and physical properties of the paper were investigated. The results showed that the paper with both inclusion complexes exhibited excellent antibacterial activity, and the antibacterial activity with β-CD-CS-CipHCl was higher than that with β-CD-Cel-CipHCl. Moreover, the addition of both β-CD-Cel-CipHCl and β-CD-CS-CipHCl affected the tensile and tear strengths of the paper. The paper with β-CD-CS-CipHCl had better physical properties than that with β-CD-Cel-CipHCl because the CS acts as a reinforcing agent in papermaking. These prepared antibacterial paper sheets may be useful for preventing wound and nosocomial infections in the medical and packaging fields

Microwave Assisted Preparation of Antimicrobial Chitosan with Guanidine Oligomers and Its Application in Hygiene Paper Products

Guanidinylated chitosan (GCS) was prepared by grafting guanidine oligomers onto chitosan under microwave irradiation. The structure of GCS characterized by FT-IR and 1H NMR verified the covalent bonding between the guanidine oligomers and chitosan; the effects of molar ratio, reaction temperature, and time were investigated and the degree of substitution of GCS reached a maximum of 25.5% under optimized conditions in this work. The resulting GCS showed significantly enhanced antimicrobial activities. The results obtained from the dynamic UV absorption of Escherichia coli (E. coli) and atomic force microscopy (AFM) revealed that the deactivation of E. coli by GCS was due to the destructing of the cell membrane and the prompt release of cytoplasm from the bacterial cells. The adsorption of GCS onto cellulose fibers and the antimicrobial efficiency of the hygiene papers with GCS were also investigated. Microwave irradiation as a green assisted method was applied to promote this reaction. This facile approach allowed chitosan to be guanidinylated without tedious preparation procedures and thus broadened its application as a biocompatible antimicrobial agent

Characterization of chicken interleukin-9 receptor alpha chain

ABSTRACT: Interleukin-9 receptor alpha chain (IL-9Rα) is the ligand-binding subunit of IL-9R that plays roles in IL-9-mediated allergy, inflammation, infection, and tumor immunity. While mammalian IL-9Rαs have been extensively investigated, avian IL-9Rα has not yet been identified and characterized. In this study, we cloned chicken IL-9Rα (chIL-9Rα) and performed a phylogenetic analysis, analyzed its tissue distribution, characterized the expression form of natural chIL-9Rα. Phylogenetic analysis showed that chIL-9Rα has less than 25% amino acid homology with mammalian IL-9Rαs. The chIL-9Rα mRNA was abundantly detected only in heart and mitogen-activated peripheral blood mononuclear cells. Furthermore, 4 monoclonal antibodies (mAbs) against chIL-9Rα were generated using prokaryotic recombinant chIL-9Rα (rchIL-9Rα). Using anti-chIL-9Rα mAbs, natural chIL-9Rα expressed on the splenocytes of chickens was observed by indirect immunofluorescence assay (IFA), and its molecular weight of 51 kDa was identified by Western blotting. Overall, our study reveals for the first time the presence of IL-9Rα in birds, and provides immunological tools for further investigating the roles of chIL-9 in diseases and immunity

Preparation of Novel Nano-Sized Hydrogel Microcapsules via Layer-By-Layer Assembly as Delivery Vehicles for Drugs onto Hygiene Paper

Hydrogel microcapsules are improved transplantation delivery vehicles for pharmaceuticals by effectively segregating the active ingredients from the surroundings and delivering them to a certain target site. Layer-by-layer (LbL) assembly is an attractive process to fabricate the nano-sized hydrogel microcapsules. In this study, nano-sized hydrogel microcapsules were prepared through LbL assembly using calcium carbonate nanoparticles (CaCO3 NPs) as the sacrificial inorganic template, sodium alginate (SA) and polyethyleneimine (PEI) as the shell materials. Ciprofloxacin was used to study the encapsulation and release properties of the hydrogel microcapsules. The hydrogel microcapsules were further adsorbed onto the paper to render antimicrobial properties. The results showed that the mean size of the CaCO3 template was reduced after dispersing into sodium n-dodecyl sulfate (SDS) solution under sonication. Transmission electron microscope (TEM) and atomic force microscope (AFM) revealed that some hydrogel microcapsules had a diameter under 200 nm, typical creases and collapses were found on the surface. The nano-sized PEI/SA hydrogel microcapsules showed high loading capacity of ciprofloxacin and a sustained release. PEI/SA hydrogel microcapsules rendered good antimicrobial properties onto the paper by the adsorption of hydrogel microcapsules, however, the mechanical properties of the hygiene paper were decreased