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Acute pancreatitis (AP) is a severe pancreatic disorder that remains associated with high mortality due to a lack of effective drugs and management strategies. This study aimed to investigate the molecular pathogenic mechanisms of AP involving p53 and endoplasmic reticulum (ER) stress pathways. Expression of PRSS1 and p53 in human AP tissues was detected by immunohistochemistry and Western blotting. AP was induced with caerulein in humanized PRSS1 transgenic mice, and its severity was verified by histological imaging, evaluation of edema, serum amylase, and trypsin activity assays. A transferase-mediated d-UTP nick end-labeling assay was performed to evaluate acinar cell apoptosis associated with AP. The expression of ER stress genes was assessed by quantitative RT-PCR (qRT-PCR) and Western blotting. PRSS1 and p53 were highly expressed in human AP tissues. Expression of human PRSS1 in caerulein-treated mice induced significant acinar cell apoptosis and AP progression. P53 knockout significantly suppressed AP progression in humanized PRSS1 transgenic mice. The ER stress pathway was activated by PRSS1 and mediated the progression of AP in mouse pancreatic tissues. Application of a p53 inhibitor effectively ameliorated caerulein-induced AP in PRSS1 transgenic mice, while a p53 activator promoted the progression of AP. P53, which was activated by the ER stress pathway, promoted the progression of AP in mice expressing PRSS1 by inducing acinar cell apoptosis.

In this study, poly(vinyl chloride) (PVC) was electrospun into fibrous membranes and then reacted with NaN3 to generate azido-terminated PVC fibrous membranes. A propargyl-terminated poly(N-isopropylacrylamide) (PNIPAAm) was also synthesized and then grafted, through click reactions, onto the azido-terminated PVC fiber surface. Protrusion-, scale-, and joint-like structures of the PNIPAAm grafts on the PVC fibers were formed upon increasing the molecular weight of the PNIPAAm grafts. The PNIPAAm-grafted PVC fibrous mats exhibited completely wetted surfaces at 25 °C because of their high roughness. The static water contact angle of the PNIPAAm-grafted PVC fibrous mats reached 140° when the temperature was increased to 45 °C. This thermoresponsive behavior was significantly greater than that of the PNIPAAm grafted on a flat surface. Temperature-responsive membranes were constructed having a pore size of 1.38 μm and applied as protein valves to block and release an antibody (fluorescein-conjugated AffiniPure goat anti-rabbit IgG). At 25 °C, the collection efficiency remained at 94% for antibody concentrations up to 60 ng/L. As the temperature increased to 45 °C, the collection efficiency decreased abruptly, to 4%, when the antibody concentration was greater than 20 ng/L. Accordingly, this system of PNIPAAm-grafted PVC fibers functioned as a protein valve allowing the capture and concentration of proteins.

Poly(vinyl chloride) (PVC) was electrospun as fibrous mats to treat with NaN3. The secondary chlorines of PVC were modified to generate azido-terminated electrospun PVC fibrous mats (EPFMs). Sequentially, propargyl-terminated poly(N-isopropylacrylamide) (PNIPAAm) was further synthesized and grafted onto the azido-terminated EPFMs via a click reaction resulting in a scale-like structure on the fibers. The static water contact angles (SWCAs) of the grafted EPFMs reached 0 and 140° when the working temperatures were 25 and 45 °C, respectively. In contrast to the grafts on a smooth surface, the change in SWCA from 25 to 45 °C was enhanced significantly. EPFMs with PNIPAAm grafts could immobilize an antibody (antiHA), and they could be used for an immunosorbent assay. After coupling with an antigen (HRP-HA) at 80 ng mL−1 for 8 min, the hydrophobicity of EPFMs with PNIPAAm grafts disappeared completely at 45 °C. In addition, the grafted EPFMs exhibited a much more dark blue color than those without the PNIPAAm grafts. SWCA below 10° at 45 °C could be exploited as an index to determine the limit of detection (LOD) as 80 ng mL−1. The immunosorbent assay of EPFMs with PNIPAAm grafts experimentally exhibited high potential in a simple set-up for biosensing due to the unique sensitivity and selectivity of the grafted EPFMs.

In this study, the electrochemiluminescent (ECL) behavior of Nickel(II) tetrasulfophthalocyanine (NiTSPc)/H2O2 on a heated indium tin oxide (ITO) electrode was investigated. The effect of pH value, electrochemical scan mode, concentration of NiTSPc and electrode surface temperature on the ECL intensities had been studied in detail. Based on the fact that the ECL of NiTSPc can be greatly enhanced by hydrogen peroxide at the ITO electrode, a new ECL biosensor for hydrogen peroxide has been developed. The possible mechanism for the ECL of NiTSPc has also been proposed.

Bone morphogenetic proteins (BMPs) play an important role in regulating osteoblast differentiation and subsequent bone formation, mainly evidenced by the induced osteogenic ability of BMP-2 from BMPs. However, BMP-2 alone does not induce the expected efficacy due to its short retention in vivo. In this study, a novel BMP-2-related peptide (designated P24) derived from the “knuckle epitope” of BMP-2 was coupled covalently to type I collagen derived from rat tail and observed under scanning electron microscopy (SEM) in low vacuum mode. The BMP-2-related peptide/collagen composite was implanted in vivo into the pocket of the quadriceps musculature of Sprague-Dawley (SD) rats and then harvested 3 or 6 weeks after surgery. It was found that lyophilized collagen retained a porous network structure with an average inner-diameter of 90 ∼ 160 μm. Based on radiographic evaluation and histological examination, BMP-2-related peptide/collagen induced significant ectopic bone formation compared to that of rat tail collagen alone as a control. Our results indicate collagen served as a good carrier for newly synthesized BMP-2-related peptide and that the BMP-2-related peptide/collagen composite was an effective substitute in bone tissue engineering.

An ideal bone graft material is the one characterized with good biocompatibility, biodegradation, osteoconductivity and osteoinductivity. In this study, a novel synthetic BMP-2-related peptide (designated P24) corresponding to residues of the knuckle epitope of BMP-2 was introduced into a biomimetic scaffold based on sintered bovine bone or true bone ceramics (TBC) and type I collagen (TBC/collagen I) using a simulated body fluid (SBF). Hydroxylapatite crystal mineralization with a Ca/P molar ratio of 1.63 was observed on the surface of P24/TBC/collagen I composite by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD) techniques. Cell adhesion rate evaluation of bone marrow stromal cells (BMSCs) seeded on materials in vitro showed that the percentage of cells attached to P24/TBC/collagen I composite was significantly higher than that of the TBC/collagen I composite. A 10 mm unilateral segmental bone defect was created in the radius of New Zealand white rabbits and randomly implanted with three groups of biomaterials (Group A: P24/TBC/collagen I composite; Group B: TBC/collagen I composite and Group C: TBC alone). Based on radiographic evaluation and histological examination, the implants of P24/TBC/collagen I composite significantly stimulated bone growth, thereby confirming the enhanced rate of bone healing compared with that of TBC/collagen I composite and TBC alone. It was concluded that BMP-2-related peptide P24 could induce nucleation of calcium phosphate crystals on the surface of TBC/collagen I composite. The TBC/collagen I composite loaded with the synthetic BMP-2-related peptide is a promising scaffold biomaterial for bone tissue engineering.

BMP-2 is one of the most important growth factors of bone regeneration. Polylactide-co-glycolic acid (PLGA), which is used as a biodegradable scaffold for delivering therapeutic agents, has been intensively investigated. In previous studies, we synthesized a novel BMP-2-related peptide (designated P24) and found that it could enhance the osteoblastic differentiation of bone marrow stromal cells (BMSCs). The objective of this study was to construct a biomimetic composite by incorporating P24 into a modified PLGA-(PEG-ASP)n copolymer to promote bone formation. In vitro, our results demonstrated that PLGA-(PEG-ASP)n scaffolds were shown to be an efficient system for sustained release of P24. Significantly more BMSCs attached to the P24/PLGA-(PEG-ASP)n and PLGA-(PEG-ASP)n membranes than to PLGA, and the cells in the two groups subsequently proliferated more vigorously than those in the PLGA group. The expression of osteogenic markers in P24/PLGA-(PEG-ASP)n group was stronger than that in the PLGA-(PEG-ASP)n and PLGA groups. Radiographic and histological examination, Western blotting and RT-PCR showed that P24/PLGA-(PEG-ASP)n scaffold could induce more effective ectopic bone formation in vivo, as compared with PLGA-(PEG-ASP)n or gelatin sponge alone. It is concluded that the PLGA-(PEG-ASP)n copolymer is a good P24 carrier and can serve as a good scaffold for controlled release of P24. This novel P24/PLGA-(PEG-ASP)n composite promises to be an excellent biomaterial for inducing bone regeneration.

The silver(II)- and manganese(III)-mediated radical reactions of 2-substituted-1,4-naphthoquinones are described. Acyl radicals generated by the oxidative decarboxylation of α-keto acids with silver(I) nitrate and persulfate undergo efficient radical addition to the C=C bond of 2-(1-hydroxyalkyl)-1,4-naphthoquinones and 2-(1-amidoalkyl)-1,4-naphthoquinones. This reaction provides an effective method for the synthesis of naphtho[2,3-c]furan-4,9-diones and benzo[f]isoindole-4,9-diones. In the presence of O 2 , manganese(III) acetate oxidation of β-keto esters also generates acyl radicals, which then undergo radical addition to 2-(1-amido-alkyl)-1,4-naphthoquinones, and subsequently, benzo[f]iso-indole-4,9-diones are produced.

Silver-catalyzed reaction of hydroxymethyl-substituted naphthoquinones (I) with α-oxocarboxylic acids (II) provides access towards naphtho-fused furan derivatives (III).

A capillary electrophoresis (CE) method coupled with electrochemiluminescence (ECL) detection for the analysis of glyphosate (GLY) and its major metabolite aminomethylphosphonic acid (AMPA) is presented. Complete separation of GLY and AMPA was achieved in 8 min using a background electrolyte of 20 mM sodium phosphate (pH 9.0) and a separation voltage of 21 kV. ECL detection was performed with an indium tin oxide (ITO) working electrode bias at 1.6 V (vs. a Pt-wire reference) in a 30 0mM sodium phosphate buffer (pH 8.0) containing 3.5mM Ru(bpy)3 2+ (where bpy=2.2'-bipyridyl). Linear correlation (r>or=0.997) between ECL intensity and analyte concentration was obtained in the ranges 0.169-16.9 and 5.55-111 microg ml(-1) for GLY and AMPA, respectively. The limits of detection (LODs) for GLY and AMPA in water were 0.06 microg ml(-1) and 4.04 microg ml(-1), respectively. The developed method was applied to the analysis of GLY in soybeans. The LOD of GLY in soybean was 0.6 microg g(-1). Total analysis time including sample pretreatment was less than 1h.