Visualization of in situ hydrogels by MRI in vivo

2016 ◽  
Vol 4 (7) ◽  
pp. 1343-1353 ◽  
Author(s):  
Jia Liu ◽  
Ke Wang ◽  
Jie Luan ◽  
Zhi Wen ◽  
Lei Wang ◽  
...  

Chitosan and PEG-based self-healable in situ hydrogel developed as a long-term MRI reporter.

scholarly journals A novel universal nano-luciferase-involved reporter system for long-term probing food-borne probiotics and pathogenic bacteria in mice by in situ bioluminescence imaging

RSC Advances ◽  
2020 ◽  
Vol 10 (22) ◽  
pp. 13029-13036 ◽  
Author(s):  
Ning Zhao ◽  
Jing-Min Liu ◽  
Shuang Liu ◽  
Xue-Meng Ji ◽  
Huan Lv ◽  
...  
Keyword(s):  
Experimental Design ◽  
Pathogenic Bacteria ◽  
Bioluminescence Imaging ◽  
Reporter System ◽  
Bioluminescent Bacteria ◽  
Foodborne Bacteria ◽  
Food Borne

Schematic illustration of the preparation of bioluminescent bacteria and the experimental design of tracing of the foodborne bacteria in vivo.

The Primary Investigation on Biological Effect of Mesoporous Bioactive Glass In Vivo

2013 ◽  
Vol 750-752 ◽  
pp. 1651-1655
Author(s):  
Bai Yan Sui ◽  
Cheng Tie Wu ◽  
Jiao Sun
Keyword(s):  
Bioactive Glass ◽  
Biological Effect ◽  
Degradation Products ◽  
Long Term Effect ◽  
Liver And Kidney ◽  
Mesoporous Bioactive Glass

Mesoporous bioactive glass (MBG) has superior bioactivity and degradation than non-mesoporous bioactive glass (BG) in vitro. But the biological effect of MBG in vivo is still unknown. In this study, MBG powders with 20μm were implanted into the femoral condyles in SD rats. BG powders with 20μm were used as a control. The local degradation and osteogenesis were observed at 1 week and 4 weeks after implantation, and the systemic toxicity of the degradation products were also evaluated simultaneously. The results revealed MBG powders had the faster rate of degradation and better osteogenesis effect than BG powders at 4 weeks, although the most of material still remained in situ. Histopathological analyses indicated the degradation products did not have any damage to major organs such as liver and kidney. In conclusion, this preliminary study demonstrated that MBG powders have more excellent biological effect at 4 weeks than that of BG in vivo. However the long-term effect needs to be confirmed.

scholarly journals A Liquid Hydrogel to Restore Long Term Corneal Integrity After Perforating and Non-Perforating Trauma in Feline Eyes

2021 ◽  
Vol 9 ◽  
Author(s):  
Alejandro Juarez ◽  
Mohamed Djallali ◽  
Marilyse Piché ◽  
Mathieu Thériault ◽  
Marc Groleau ◽  
...  
Keyword(s):  
Corneal Transplantation ◽  
Specular Microscopy ◽  
Slit Lamp ◽  
Cyanoacrylate Glue ◽  
Promising Alternative ◽  
A Cell ◽  
Feline Model

Purpose: To evaluate long-term in vivo functionality of corneas regenerated using a cell-free, liquid hydrogel filler (LiQD Cornea) after deep corneal trauma in the feline model.Methods: Two healthy cats underwent 4 mm diameter stepwise 250/450 µm deep surgical corneal ablation with and without needle perforation. The filler comprising 10% (w/w) collagen-like peptide conjugated to polyethylene glycol (CLP-PEG) and 1% fibrinogen and crosslinked with 2% (w/w) 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM), was applied to the wound bed previously coated with thrombin (250 U/ml). In situ gelation occurred within 5 min, and a temporary tarsorrhaphy was performed. Eyes were examined weekly for 1 month, then monthly over 12 months. Outcome parameters included slit-lamp, Scheimpflug tomography, optical coherence tomography, confocal and specular microscopy, and immunohistochemistry studies.Results: The gelled filler was seamlessly incorporated, supporting smooth corneal re-epithelialization. Progressive in-growth of keratocytes and nerves into the filler corresponding to the mild haze observed faded with time. The regenerated neo-cornea remained stably integrated throughout the 12 months, without swelling, inflammation, infection, neovascularization, or rejection. The surrounding host stroma and endothelium remained normal at all times. Tomography confirmed restoration of a smooth surface curvature.Conclusion: Biointegration of this hydrogel filler allowed stable restoration of corneal shape and transparency in the feline model, with less inflammation and no neovascularization compared to previous reports in the minipig and rabbit models. It offers a promising alternative to cyanoacrylate glue and corneal transplantation for ulcerated and traumatized corneas in human patients.

scholarly journals Long-term evolution of antibiotic persistence in P. aeruginosa lung infections

2021 ◽  
Author(s):  
Melanie Ghoul ◽  
Sandra B Andersen ◽  
Helle Krogh Johansen ◽  
Lars Jelsbak ◽  
Søren Molin ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Resistance Mechanisms ◽  
Term Evolution ◽  
Bacterial Clone ◽  
Evolution Of Resistance ◽  
Lung Infections

Pathogenic bacteria respond to antibiotic pressure with the evolution of resistance but survival can also depend on their ability to tolerate antibiotic treatment, known as persistence. While a variety of resistance mechanisms and underlying genetics are well characterised in vitro and in vivo, the evolution of persistence, and how it interacts with resistance in situ is less well understood. We assayed for persistence and resistance with three clinically relevant antibiotics: meropenem, ciprofloxacin and tobramycin, in isolates of Pseudomonas aeruginosa from chronic cystic fibrosis lung infections spanning up to forty years of evolution. We find evidence that persistence is under positive selection in the lung and that it can particularly act as an evolutionary stepping stone to resistance. However, this pattern is not universal and depends on the bacterial clone type and antibiotic used, indicating an important role for antibiotic mode of action.

scholarly journals Acellular Small-Diameter Tissue-Engineered Vascular Grafts

2019 ◽  
Vol 9 (14) ◽  
pp. 2864 ◽  
Author(s):  
Zhen Li ◽  
Xinda Li ◽  
Tao Xu ◽  
Lei Zhang
Keyword(s):  
Effective Means ◽  
Vascular Grafts ◽  
Small Diameter ◽  
Test Results ◽  
In Vivo Test ◽  
Current State

Tissue-engineered vascular grafts (TEVGs) are considered one of the most effective means of fabricating vascular grafts. However, for small-diameter TEVGs, there are ongoing issues regarding long-term patency and limitations related to long-term in vitro culture and immune reactions. The use of acellular TEVG is a more convincing method, which can achieve in situ blood vessel regeneration and better meet clinical needs. This review focuses on the current state of acellular TEVGs based on scaffolds and gives a summary of the methodologies and in vitro/in vivo test results related to acellular TEVGs obtained in recent years. Various strategies for improving the properties of acellular TEVGs are also discussed.

Perfusion of canine liver in vivo

1960 ◽  
Vol 15 (4) ◽  
pp. 687-690 ◽  
Author(s):  
William C. Shoemaker ◽  
Frederick G. Panico ◽  
William F. Walker ◽  
David H. Elwyn
Keyword(s):  
Whole Blood ◽  
Normal Pressure ◽  
Systemic Circulation ◽  
Term Survival ◽  
Concentration Changes ◽  
Neural Influences ◽  
Systemic Condition

A method is described for perfusing the canine liver in vivo and in situ with heparinized whole blood, together with preliminary data on concentration changes of several selected constituents of the perfusing blood or plasma. The porta hepatis is denervated in order to minimize neural influences on the hepatic vascular resistance. Prior to perfusion catheters are placed in the vessels without obstructing the blood flow and ligatures or nooses are loosely placed around the catheterized vessels. During this time the blood pressure and systemic condition of the animal is carefully maintained with transfusions and other fluids. When the ligatures are simultaneously drawn up and tied, the catheters become, in effect, cannulas, and the hepatic circulation is instantaneously and completely divorced from the remaining systemic circulation; at no time is there interruption of normal pressure and flow of oxygenated blood to the liver. Thus, hepatic swelling or congestion, which is thought to limit the perfusion, is minimized by denervation, minimal manipulation of the liver itself, maintenance of the animal's condition prior to the onset of perfusion, instantaneous changeover to the perfusing system and the use of heparinized, whole blood. After completion of the perfusion the normal vascular relationships may be re-established and, on occasion, long-term survival may be expected. Submitted on October 1, 1959

scholarly journals LTP induction boosts glutamate spillover by driving withdrawal of astroglia

2018 ◽  
Author(s):  
Christian Henneberger ◽  
Lucie Bard ◽  
Aude Panatier ◽  
James P. Reynolds ◽  
Olga Kopach ◽  
...  
Keyword(s):  
Long Term Potentiation ◽  
Advanced Imaging ◽  
Memory Mechanism ◽  
Term Potentiation ◽  
Point To Point ◽  
The Brain ◽  
Synaptic Remodelling

SUMMARYExtrasynaptic actions of glutamate are limited by high-affinity transporters on perisynaptic astroglial processes (PAPs), which helps to maintain point-to-point transmission in excitatory circuits. Memory formation in the brain is associated with synaptic remodelling, but how this remodelling affects PAPs and therefore extrasynaptic glutamate actions is poorly understood. Here we used advanced imaging methods, in situ and in vivo, to find that a classical synaptic memory mechanism, long-term potentiation (LTP), triggers withdrawal of PAPs from potentiated synapses. Optical glutamate sensors combined with patch-clamp and 3D molecular localisation reveal that LTP induction thus prompts a spatial retreat of glial glutamate transporters, boosting glutamate spillover and NMDA receptor-mediated inter-synaptic cross-talk. The LTP-triggered PAP withdrawal involves NKCC1 transporters and the actin-controlling protein cofilin but does not depend on major Ca2+-dependent cascades in astrocytes. We have therefore uncovered a mechanism by which synaptic potentiation could alter signal handling by multiple nearby connections.

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