Pericardial Patch Angioplasty Heals via an Ephrin-B2 and CD34 Positive Cell Mediated Mechanism

Pericardial patches are commonly used in vascular surgery to close arteriotomies. The mechanism of early healing after patch implantation is still not well defined. We used a rat aortic patch model to assess pericardial patch healing and examined Ephrin-B2, a marker of arterial identity, expression within the post-implantation patch. We also determined whether endothelial progenitor cells (EPC) are associated with early patch healing in the arterial environment.Wistar rats (200-250 grams) underwent infrarenal aortic arteriotomy and then closure via bovine or porcine pericardial patch angioplasty. Control groups included subcutaneously implanted patches. Patches were harvested at 0-30 days and analyzed by histology, immunohistochemistry, immunofluorescence and Western blot as well as quantitative PCR.Prior to implantation, pericardial patches are largely composed of collagen and are acellular. Following arterial implantation, increasing numbers of CD68-positive cells as well as Ephrin-B2 and CD34 dual-positive cells are found within both bovine and porcine pericardial patches, whereas the infiltrating cells are negative for vWF and α-actin. Porcine patches have a luminal monolayer of cells at day 7, compared to bovine patches that have fewer luminal cells. Subcutaneously implanted patches do not attract Ephrin-B2/CD34-positive cells. By day 30, both bovine and porcine pericardial patches develop a neointima that contains Ephrin-B2, CD34, and VEGFR2-positive cells.Both CD68-positive and Ephrin-B2 and CD34 dual-positive cells infiltrate the pericardial patch early after implantation. Arteriotomy closure via pericardial patch angioplasty shows patch adaptation to the arterial environment that may involve a foreign body response as well as localization of EPC. Arterial remodeling of pericardial patches support endothelialization and may represent a paradigm of healing of scaffolds used for tissue engineering

Light People: Prof. Eric Mazur speaks about ultrafast optics and education

Editorial Prof. Eric Mazur is a great influencer over and beyond the optics community. As a physicist, he is a pioneer of ultrafast optics and was one of the inventors of colliding-pulse mode-locked laser. As an educator, he not only gave talks to thousands, but also revolutionized teaching with his globally renowned methodology “Peer Instruction”. As a leader and entrepreneur, he co-founded several companies and was President of Optica (formerly the Optical Society) and currently is the Chair of the Optica Foundation. Here, Light: Science & Applications talked with Prof. Eric Mazur about his opinions on research, education and industry. The full interview video can be found in the Supplementary File

Investigation of the Effect of the Degree of Processing of Radix Rehmanniae Preparata (Shu Dihuang) on Shu Dihuangtan Carbonization Preparation Technology

Carbonization of Radix Rehmanniae Preparata (Shu Dihuangtan) via stir-frying could increase its homeostasis maintaining and antidiarrheal effects. To ensure these pharmacological functions, the quality of the raw material (processed Rehmanniae Radix) must be well controlled. Therefore, we analyzed the effects of different degrees of processing and adjuvants on processed Rehmanniae Radix (Shu Dihuang) by High Performance Liquid Chromatography (HPLC) chromatographic fingerprints, thermal gravimetric analysis and Fourier transform infrared spectroscopy (FTIR). Based on the results from HPLC fingerprints combined with similarity analysis (SA) and hierarchical cluster analysis (HCA) the optimum processing method for Shu Dihuang was five cycles of steaming and polishing, which follows the ancient processing theory. The intensity of thermal weight loss rate peaked near 210.33 ± 4.32 °C or 211.33 ± 2.62 °C, which was an important indicator for the degree of processing of Shu Dihuang. A temperature near 290.89 ± 2.51 °C was the upper limit for carbonizing Shu Dihuangtan. FTIR spectroscopy analysis showed that the overall chemical composition of Shu Dihuangtan was affected by both the degree of processing and adjuvant, which are very important for its quality

A Novel Au@Cu2O-Ag Ternary Nanocomposite with Highly Efficient Catalytic Performance: Towards Rapid Reduction of Methyl Orange Under Dark Condition

Au@Cu2O core-shell nanocomposites (NCs) were synthesized by reducing copper nitrate on Au colloids with hydrazine. The thickness of the Cu2O shells could be varied by adjusting the molar ratios of Au: Cu. The results showed that the thickness of Cu2O shells played a crucial role in the catalytic activity of Au@Cu2O NCs under dark condition. The Au@Cu2O-Ag ternary NCs were further prepared by a simple galvanic replacement reaction method. Moreover, the surface features were revealed by TEM, XRD, XPS, and UV–Vis techniques. Compared with Au@Cu2O NCs, the ternary Au@Cu2O-Ag NCs had an excellent catalytic performance. The degradation of methyl orange (MO) catalyzed by Au@Cu2O-Ag NCs was achieved within 4 min. The mechanism study proved that the synergistic effects of Au@Cu2O-Ag NCs and sodium borohydride facilitated the degradation of MO. Hence, the designed Au@Cu2O-Ag NCs with high catalytic efficiency and good stability are expected to be the ideal environmental nanocatalysts for the degradation of dye pollutants in wastewater

Bovine and porcine pericardial patches, day

<p> <b>30. A</b>) Representative photomicrographs of bovine and porcine patches, low (10x) and high (40x) magnification, scale bar 80 and 30 (porcine, 40) microns. Arrow shows the neointima; arrowhead shows the patch; L, lumen. <b>B</b>) Bar graph of mean neointimal thickness, bovine and porcine patches, day 30. <b>C</b>) Photomicrographs of immunofluorescence: blue color, DAPI; green color, CD34; red color, Ephrin-B2 or VEGFR2; merge, green + red. n = 2; representative pictures are shown. Scale bar, 10 microns. <b>D</b>) Western blot of Ephrin-B2 or CD34, in bovine or porcine pericardial patch, day 0 (preimplantation) or day 30; n = 2.</p

Photomicrographs of the implanted pericardial patch.

<p><b>A</b>) The rat aorta after arteriotomy and prior to patch placement; the white arrow shows the glistening intima on the posterior wall; ruler markings are 1mm. Scale bar, 1000 microns. <b>B</b>) Completed bovine patch closure. Scale bar, 1000 microns. <b>C</b>) Completed porcine patch closure. Scale bar, 500 microns. <b>D</b>) Explanted aortic segment containing patch after harvesting and flushing. Scale bar, 1000 microns. In each graph, <b>A</b> = aorta; <b>P</b> = pericardial patch.</p

Bioreducible Cross-Linked Hyaluronic Acid/Calcium Phosphate Hybrid Nanoparticles for Specific Delivery of siRNA in Melanoma Tumor Therapy

This study introduces a novel cross-linking strategy capable of successfully stabilizing CaP nanoparticles and stimuli-responsive small interfering RNA (siRNA) release. We synthesized a polysaccharide derivative thiolated hyaluronic acid (HA-SH), which was slightly modified but multifunctional and developed a smart redox-responsive delivery system. siRNA was efficaciously condensed by calcium phosphate (CaP) via electrostatic interaction to form a positively charged inner “core”. Disulfide cross-linked HA (HA-ss-HA) was formed and played a role as an anionic outer “shell” to stabilize the CaP core. We demonstrated that the nanoparticles were stable both in the storage milieu and systemic circulation, thus overcoming the most serious disadvantage of CaP nanoparticles for gene delivery. Meanwhile, this smart system could selectively release siRNA into the cytosol by both a GSH-triggered disassembly and successful endosomal escape. Therefore, the hybrid delivery system achieved an 80% gene-silencing efficiency in vitro for both luciferase and Bcl2. Silencing of Bcl2 resulted in dramatic apoptosis of B16F10 cells. Besides, equipped with the tumor-targeting component HA, the nanoparticles significantly suppressed the growth of B16F10 xenograft tumor in mice. The anionic HA-ss-HA-equipped nanoparticles showed no apparent toxicity in vitro or in vivo, as well as showed a high transfection efficiency. Taken together, this redox-responsive, tumor-targeting smart anionic nanoparticle holds great promise for exploitation in functionalized siRNA delivery and tumor therapy

Porcine pericardial patches, day

<p> <b>7. </b><b>A</b>) Porcine pericardial patches show infiltrating cells positive for CD34, Ephrin-B2, VEGFR2, or CD68; CD34-positive cells are present as a surface monolayer, with some cells dually positive for CD34 and Ephrin-B2 or CD34 and VEGFR2; first panel is the day 0 (preimplantation) control. Photomicrographs of immunofluorescence: blue color, DAPI; green color, CD34; red color, Ephrin-B2 or VEGFR2; merge, green + red. n = 3; representative pictures are shown. Scale bar, 10 microns. <b>B</b>) Western blot of Ephrin-B2 and CD34, in porcine pericardial patch, day 0 (preimplantation) or day 7.</p

Increasing numbers of infiltrating cells into the arterial patch.

<p><b>A</b>) Photomicrographs of bovine pericardial patches, implanted into either an arterial or subcutaneous position, and shown at either high or low magnification. Scale bar, 40 microns. <b>B</b>) Graph of cell count in the patch over time; mean of 4 high power fields per patch; n = 2. *, p<0.0001.</p