scholarly journals Evaluation of a Murine Model for Testing Antimicrobial Implant Materials in the Blood Circulation System

Biomedicines ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1464
Author(s):  
Caroline Moerke ◽  
Marlen Kloss ◽  
Katharina Wulf ◽  
Sabine Illner ◽  
Sabine Kischkel ◽  
...  

Medical device-related infections are becoming a steadily increasing challenge for the health care system regarding the difficulties in the clinical treatment. In particular, cardiovascular implant infections, catheter-related infections, as well as infective endocarditis are associated with high morbidity and mortality risks for the patients. Antimicrobial materials may help to prevent medical device-associated infections and supplement the currently available therapies. In this study, we present an easy-to-handle and simplified in vivo model to test antimicrobial materials in the bloodstream of mice. The model system is composed of the implantation of a bacteria-laden micro-stent scaffold into the murine tail vein. Our model enables the simulation of catheter-related infections as well as the development of infective endocarditis specific pathologies in combination with material testing. Furthermore, this in vivo model can cover two phases of the biofilm formation, including both the local tissue response to the bacterial biofilm and the systemic inflammatory response against circulating bacteria in the bloodstream that detached from a mature biofilm.

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Christine L. Farnsworth ◽  
Peter O. Newton ◽  
Eric Breisch ◽  
Michael T. Rohmiller ◽  
Jung Ryul Kim ◽  
...  

Study Design. Combinations of metal implants (stainless steel (SS), titanium (Ti), and cobalt chrome (CC)) were placed in porcine spines. After 12 months, tissue response and implant corrosion were compared between mixed and single metal junctions. Objective. Model development and an attempt to determine any detriment of combining different metals in posterior spinal instrumentation. Methods. Yucatan mini-pigs underwent instrumentation over five unfused lumbar levels. A SS rod and a Ti rod were secured with Ti and SS pedicle screws, SS and Ti crosslinks, SS and CC sublaminar wires, and Ti sublaminar cable. The resulting 4 SS/SS, 3 Ti/Ti, and 11 connections between dissimilar metals per animal were studied after 12 months using radiographs, gross observation, and histology (foreign body reaction (FBR), metal particle count, and inflammation analyzed). Results. Two animals had constructs in place for 12 months with no complications. Histology of tissue over SS/SS connections demonstrated 11.1 ± 7.6 FBR cells, 2.1 ± 1.7 metal particles, and moderate to extensive inflammation. Ti/Ti tissue showed 6.3 ± 3.8 FBR cells, 5.2 ± 6.7 particles, and no to extensive inflammation (83% extensive). Tissue over mixed components had 14.1 ± 12.6 FBR cells and 13.4 ± 27.8 particles. Samples surrounding wires/cables versus other combinations demonstrated FBR (12.4 ± 13.5 versus 12.0 ± 9.6 cells, P = 0.96), particles (19.8 ± 32.6 versus 4.3 ± 12.7, P = 0.24), and inflammation (50% versus 75% extensive, P = 0.12). Conclusions. A nonfusion model was developed to study corrosion and analyze biological responses. Although no statistical differences were found in overlying tissue response to single versus mixed metal combinations, galvanic corrosion between differing metals is not ruled out. This pilot study supports further investigation to answer concerns when mixing metals in spinal constructs.


2020 ◽  
Vol 18 ◽  
Author(s):  
Alireza Partoazar ◽  
Fatemeh Rahmani Bideskan ◽  
Nasrin Takzaree ◽  
Mohammad Mehdi Soltan Dallal

Background: Infectious diseases, whether intracellular or extracellular infections, biofilm-mediated, or medical device- associated have always been a global problem in public health causing millions of deaths each year. The aim of this study was to evaluate the antibiofilm activity of ZnO/ZeoNC against K. pneumoniae along with biocompatibility of nanocomposite in vivo model. Objective: The formation of biofilm by K. pneumoniae in the catheter-associated urinary tract causes a nosocomial infection. In this regard, antimicrobial nanomaterials have emerged as potent effective agents against biofilm formation. Nevertheless, nanoparticles have already been a challenge with possible side effects such as inflammation. The ZnO/ZeoNC may exhibit anti-biofilm property with minimal adverse effects. Methods: The biofilm formation of K. pneumoniae strains was exposed to ZnO/ZeoNC and then SEM imaging was performed for morphological investigation of bacteria in biofilm state. The quantity of mice tissue response to ZnO/ZeoNC embedded polyethylene tube also analyzed on the tissue of mice during the 30-day experiment. Results: The results of this study showed that ZnO/ZeoNC has the significant antibiofilm activity against K. pneumoniae strains in its sublethal doses. The ZnO/ZeoNC also caused deformation on K. pneumoniae biofilm. In addition, ZnO/ZeoNC also reduced inflammatory response in cell tissue of rats subjected to polyethylene tube. Conclusion: ZnO/ZeoNC can be used potentially against the infections due to K. pneumonia biofilm without irritability on the biotic surface such as urinary tract.


ASN NEURO ◽  
2021 ◽  
Vol 13 ◽  
pp. 175909142110106
Author(s):  
Zheng-Long Jin ◽  
Wen-Ying Gao ◽  
Shao-Jun Liao ◽  
Tao Yu ◽  
Qing Shi ◽  
...  

Intracerebral haemorrhage (ICH) is a devastating subtype of stroke with high morbidity and mortality. It has been reported that paeonol (PAN) inhibits the progression of ICH. However, the mechanism by which paeonol mediates the progression of ICH remains unclear. To mimic ICH in vitro, neuronal cells were treated with hemin. An in vivo model of ICH was established to detect the effect of paeonol on ferroptosis in neurons during ICH. Cell viability was tested by MTT assay. Furthermore, cell injury was detected by GSH, MDA and ROS assays. Ferroptosis was examined by iron assay. RT-qPCR and western blotting were used to detect gene and protein expression, respectively. The correlation among HOTAIR, UPF1 and ACSL4 was explored by FISH, RNA pull-down and RIP assays. Paeonol significantly inhibited the ferroptosis of neurons in ICH mice. In addition, paeonol significantly reversed hemin-induced injury and ferroptosis in neurons, while this phenomenon was notably reversed by HOTAIR overexpression. Moreover, paeonol notably inhibited ferroptosis in hemin-treated neuronal cells via inhibition of ACSL4. Additionally, HOTAIR bound to UPF1, and UPF1 promoted the degradation of ACSL4 by binding to ACSL4. Furthermore, HOTAIR overexpression reversed paeonol-induced inhibition of ferroptosis by mediating the UPF1/ACSL4 axis. Paeonol inhibits the progression of ICH by mediating the HOTAIR/UPF1/ACSL4 axis. Therefore, paeonol might serve as a new agent for the treatment of ICH.


Author(s):  
U Lichtenauer ◽  
PL Schmid ◽  
A Oßwald ◽  
I Renner-Müller ◽  
M Reincke ◽  
...  
Keyword(s):  

1997 ◽  
Vol 78 (04) ◽  
pp. 1242-1248 ◽  
Author(s):  
David E Newby ◽  
Robert A Wright ◽  
Christopher A Ludlam ◽  
Keith A A Fox ◽  
Nicholas A Boon ◽  
...  

SummaryThe effects on blood flow and plasma fibrinolytic and coagulation parameters of intraarterial substance P, an endothelium dependent vasodilator, and sodium nitroprusside, a control endothelium independent vasodilator, were studied in the human forearm circulation. At subsystemic locally active doses, both substance P (2-8 pmol/min) and sodium nitroprusside (2-8 μg/min) caused dose-dependent vasodilatation (p <0.001 for both) without affecting plasma concentrations of PAI-1, von Willebrand factor antigen or factor VIII:C activity. Substance P caused local increases in t-PA antigen and activity (p <0.001) in the infused arm while sodium nitroprusside did not. At higher doses, substance P increased blood flow and t-PA concentrations in the noninfused arm. We conclude that brief, locally active and subsystemic infusions of intraarterial substance P cause a rapid and substantial local release of t-PA which appear to act via a flow and nitric oxide independent mechanism. This model should provide a useful and selective method of assessing the in vivo capacity of the forearm endothelium to release t-PA acutely.


2006 ◽  
Vol 66 (S 01) ◽  
Author(s):  
N Ochsenbein-Kölble ◽  
J Jani ◽  
G Verbist ◽  
L Lewi ◽  
K Marquardt ◽  
...  

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