scholarly journals Osseointegration of Zirconia Implants after UV-Light or Cold Atmospheric Plasma Surface Treatment In Vivo

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 496
Author(s):  
Lisa Krautwald ◽  
Ralf Smeets ◽  
Carolin Stolzer ◽  
Rico Rutkowski ◽  
Linna Guo ◽  
...  
Keyword(s):  
Uv Light ◽  
Atmospheric Plasma ◽  
Control Group ◽  
Plasma Surface Treatment ◽  
Bone To Implant Contact ◽  
Parietal Bones ◽  
Zirconia Implants ◽  
Over Time

The influence of UV light and non-thermal plasma on the osseointegration of yttria-stabilized zirconia implants (Y-TZP) comparing the two methods is unclear. The aim of this study was to show the influence of these methods on the osseointegration of dental zirconia implants in an animal model. A total of 54 implants were either untreated, treated with UV light (UV), or non-thermal oxygen plasma for 12 min and inserted into the parietal bones of six domestic pigs. The animals were sacrificed after a healing interval of two, four, and nine weeks. The degree of osseointegration was determined using histomorphometric determination of bone-to-implant contact values (BIC) and the bone-to-implant contact values within the retentive parts of the implants (BAFO). BIC values decreased in all groups after four weeks of healing and re-increased after nine weeks in all groups. BAFO increased significantly over time in all groups. However, there were no statistically significant differences in BIC and BAFO values between the control group and the test groups and over time. Clinical studies may follow to confirm the influence of cold plasma and UV light on the healing and survival of zirconia implants.

scholarly journals Stability and ocular biodistribution of topically administered PLGA nanoparticles

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sean Swetledge ◽  
Renee Carter ◽  
Rhett Stout ◽  
Carlos E. Astete ◽  
Jangwook P. Jung ◽  
...  
Keyword(s):  
Uv Light ◽  
Light Exposure ◽  
Polymeric Nanoparticles ◽  
Plga Nanoparticles ◽  
Eye Disease ◽  
Control Group ◽  
Eye Tissues ◽  
Nanoparticle Morphology ◽  
The Stability

AbstractPolymeric nanoparticles have been investigated as potential delivery systems for therapeutic compounds to address many ailments including eye disease. The stability and spatiotemporal distribution of polymeric nanoparticles in the eye are important regarding the practical applicability and efficacy of the delivery system in treating eye disease. We selected poly(lactic-co-glycolic acid) (PLGA) nanoparticles loaded with lutein, a carotenoid antioxidant associated with eye health, as our model ophthalmic nanodelivery system and evaluated its stability when suspended in various conditions involving temperature and light exposure. We also assessed the ocular biodistribution of the fluorescently labeled nanoparticle vehicle when administered topically. Lutein-loaded nanoparticles were stable in suspension when stored at 4 °C with only 26% lutein release and no significant lutein decay or changes in nanoparticle morphology. When stored at 25 °C and 37 °C, these NPs showed signs of bulk degradation, had significant lutein decay compared to 4 °C, and released over 40% lutein after 5 weeks in suspension. Lutein-loaded nanoparticles were also more resistant to photodegradation compared to free lutein when exposed to ultraviolet (UV) light, decaying approximately 5 times slower. When applied topically in vivo, Cy5-labled nanoparticles showed high uptake in exterior eye tissues including the cornea, episcleral tissue, and sclera. The choroid was the only inner eye tissue that was significantly higher than the control group. Decreased fluorescence in all exterior eye tissues and the choroid at 1 h compared to 30 min indicated rapid elimination of nanoparticles from the eye.

scholarly journals Evaluation of spectral photon counting computed tomography K-edge imaging for determination of gold nanoparticle biodistribution in vivo

Nanoscale ◽  
2017 ◽  
Vol 9 (46) ◽  
pp. 18246-18257 ◽  
Author(s):  
Salim Si-Mohamed ◽  
David P. Cormode ◽  
Daniel Bar-Ness ◽  
Monica Sigovan ◽  
Pratap C. Naha ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Quantitative Determination ◽  
Gold Nanoparticle ◽  
Photon Counting ◽  
Non Invasive ◽  
Over Time

A new spectral photon-counting CT prototype has the potential for non-invasive quantitative determination of gold nanoparticle biodistribution in vivo over time.

scholarly journals Development of Antimicrobial Phototreatment Tolerance: Why the Methodology Matters

2021 ◽  
Vol 22 (4) ◽  
pp. 2224
Author(s):  
Aleksandra Rapacka-Zdonczyk ◽  
Agata Wozniak ◽  
Joanna Nakonieczna ◽  
Mariusz Grinholc
Keyword(s):  
Uv Light ◽  
Genetic Material ◽  
Atmospheric Plasma ◽  
In Vivo Studies ◽  
Tolerance Development ◽  
Microbial Drug Resistance ◽  
Development Of Resistance ◽  
Cell Envelopes

Due to rapidly growing antimicrobial resistance, there is an urgent need to develop alternative, non-antibiotic strategies. Recently, numerous light-based approaches, demonstrating killing efficacy regardless of microbial drug resistance, have gained wide attention and are considered some of the most promising antimicrobial modalities. These light-based therapies include five treatments for which high bactericidal activity was demonstrated using numerous in vitro and in vivo studies: antimicrobial blue light (aBL), antimicrobial photodynamic inactivation (aPDI), pulsed light (PL), cold atmospheric plasma (CAP), and ultraviolet (UV) light. Based on their multitarget activity leading to deleterious effects to numerous cell structures—i.e., cell envelopes, proteins, lipids, and genetic material—light-based treatments are considered to have a low risk for the development of tolerance and/or resistance. Nevertheless, the most recent studies indicate that repetitive sublethal phototreatment may provoke tolerance development, but there is no standard methodology for the proper evaluation of this phenomenon. The statement concerning the lack of development of resistance to these modalities seem to be justified; however, the most significant motivation for this review paper was to critically discuss existing dogma concerning the lack of tolerance development, indicating that its assessment is more complex and requires better terminology and methodology.

Gestational coagulopathy: breakthrough in views on prevention of bleeding

2017 ◽  
pp. 40-46
Author(s):  
M. Makarenko ◽  
◽  
D. Govsieiev ◽  
A. Slobodenyuk ◽  
V. Berestovoy ◽  
...  
Keyword(s):  
Blood Loss ◽  
Blood Clotting ◽  
Massive Bleeding ◽  
Control Group ◽  
Third Trimester ◽  
Hemostatic System ◽  
Waterfall Model ◽  
The 19Th Century

Nowadays, for understanding the mechanisms of hemostasis used the «cascade» (the waterfall) model for process of blood clotting. From the end of the 19th century, scientists have been trying to unravel the mechanism of blood clotting, simulate hemostasis. Attempts to assess the system as a whole, as a single functioning complex, led to a method, known as, thromboelastography (TEG). The objective: examine the value of the TEG in prevention of bleeding in pregnant with a low level of platelets. Patients and methods. Аnalysis of pregnant women during the third trimester with a level of platelets below 150*109/l was done. All women tested with TEG method. The main group (MG) consist of 91 woman with changes in the hemostasis system. MG randomly divided into 2 subgroups. In the I subgroup 48 women received infusion of blood components. In the II subgroup 43 women without correction in system of hemostasis. The control group (CG) consist of 44 women with platelet level more than 150*109/l, without pathological changes according to TEG. Results. Comparison of blood loss during childbirth and cesarean section in subgroup I and II, as well as in CG, demonstrates less blood loss I subgroup in comparison with II subgroup (p < 0.05). Smallest blood loss noted in CG compared to the MG (p<0.05). Conclusions. 1. Our research shows the value of the TEG in bleeding prevention in women with low levels of platelets. In general, TEG method shows the overall status of the hemostatic system in vivo. 2.Determination of indicators of the hemostatic system is extremely important, especially in cases where it expected to «mandatory» blood loss during childbirth, surgeries etc. Proper correction hemostatic changes based on TEG data helps to prevent the development of massive bleeding. Key words: thromboelastography, obstetric hemorrhage, thrombocytopenia, hemostasis.

scholarly journals Bone Response to Conventional Titanium Implants and New Zirconia Implants Produced by Additive Manufacturing

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4405
Author(s):  
Jin-Cheol Kim ◽  
In-Sung Luke Yeo
Keyword(s):  
Laser Scanning ◽  
Titanium Implants ◽  
Laser Scanning Microscopy ◽  
The Other ◽  
Confocal Laser ◽  
Bone Response ◽  
3D Printed ◽  
Bone To Implant Contact ◽  
Zirconia Implants

The aim of the present study was to evaluate the in vivo bone response to an additively manufactured zirconia surface compared to osseointegration into titanium (Ti) surfaces. Scanning electron microscopy, confocal laser scanning microscopy, and electron spectroscopy for chemical analysis were performed to assess the surface characteristics of implant specimens. For the in vivo evaluation, eight Ti implants and eight 3D-printed zirconia implants were used. The surface of four Ti implants was sandblasted, large-grit, and acid-etched (Ti-SLA group), while those of the other four Ti implants were left untreated (Ti-turned group). The zirconia implants had no further surface modification. Implants were placed into the tibiae of four rabbits; two received the Ti-SLA and zirconia implants and the other two received Ti-turned and zirconia implants. The experimental animals were sacrificed after four weeks of surgery, and the undecalcified microscopic slides were prepared. The bone–implant interface was analyzed by histomorphometry to evaluate the bone response. The degree of surface roughness showed that Ti-SLA was the highest, followed by zirconia and Ti-turned surfaces. The 3D-printed zirconia surface showed similar bone-to-implant contact to the Ti-turned surface, and Ti-SLA had the most bone-to-implant contact. The additively manufactured zirconia implant surface is biocompatible with respect to osseointegration compared to the commercially pure Ti surface.

Tumor hypoxia as a mechanism of resistance to bevacizumab in a murine model.

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e13111-e13111 ◽  
Author(s):  
Linda Heijmen ◽  
Otto C. Boerman ◽  
Cornelis J. A. Punt ◽  
E. Ter Voert ◽  
Wim J.G. Oyen ◽  
...  
Keyword(s):  
Imaging Techniques ◽  
Tumor Hypoxia ◽  
Therapy Resistance ◽  
Control Group ◽  
Vascular Density ◽  
Hypoxic Fraction ◽  
Induced Changes ◽  
T2 Mri ◽  
Over Time

e13111 Background: Despite the promise of preclinical and early phase clinical studies, the efficacy of bevacizumab in solid tumors is more limited than expected. One of the presumed reasons is the induction of tumor hypoxia by the anti-angiogenic effects of bevacizumab, leading to therapy resistance. The aim of this study was to assess the effect of bevacizumab on tumor hypoxia in vivo in a colorectal cancer model, using functional imaging techniques. Methods: Nude mice with s.c. LS174T colon carcinoma xenografts (0.05 - 0.3 cm3) were treated with bevacizumab (5 mg/kg; 2/wk, i.p.) or saline as a control. To assess tumor hypoxia in vivo 18F-MISO-PET microPET or T2*-MRI images were acquired of separate groups of mice (n=5) before treatment and at day 2, 6 and 10 days after start of treatment. Tumors were harvested directly after imaging to microscopically assess the hypoxic fraction (pimonidazole staining) and vascular density (9F1 staining). Results: Linear regression analyses showed that FMISO uptake increased significantly more over time in the control group than in the bevacizumab group (beta -0.44, p=0.02), indicating that bevacizumab reduced the inherent increase in tumor hypoxia over time. T2* time increased significantly less in the bevacizumab group (beta -0.45, p=0.01), indicating a higher deoxyhemoglobine concentration, which might indicate a higher perfusion of the tumor and thus less hypoxia. The hypoxic fraction did not change over time and no difference was observed between the tumors in the treated and the control group. Vessel density significantly decreased over time in the bevacizumab group (beta -0.25, p=0.05), while the hypoxic fraction remained unchanged in the control group. Conclusions: The bevacizumab-induced changes in the tumor were most prominent at 10 days after treatment initiation, implying a build-up effect of repeated bevacizumab administration. The treatment induced changes could be detected with both T2*-MRI as well as with FMISO microPET. Bevacizumab did not induce tumor hypoxia, despite the observed decrease in vascular density. Therefore, induction of tumor hypoxia as a resistance mechanism to bevacizumab treatment seems unlikely.

scholarly journals Cold Atmospheric Plasma, Platelet-Rich Plasma, and Nitric Oxide Synthesis Inhibitor: Effects Investigation on an Experimental Model on Rats

2022 ◽  
Vol 12 (2) ◽  
pp. 590
Author(s):  
Bogdan Caba ◽  
Ioannis Gardikiotis ◽  
Ionut Topala ◽  
Ilarion Mihaila ◽  
Cosmin Teodor Mihai ◽  
...  
Keyword(s):  
Platelet Rich Plasma ◽  
Skin Flap ◽  
Atmospheric Plasma ◽  
In Vivo Model ◽  
Control Group ◽  
Synthesis Inhibitor ◽  
Cold Atmospheric Plasma ◽  
Flap Survival ◽  
Surgery Research

The evolution of reconstructive methods for defects of the human body cannot yet replace the use of flap surgery. Research is still preoccupied with the ideal techniques for offering the best chances of survival of the flaps. In our study, we investigated the effects of cold atmospheric plasma (CAP), N-nitro-L-arginine methyl ester (L-NAME), and platelet-rich plasma (PRP) injectable solutions on flap survival using an in vivo model. Twenty-four Wistar rats (four groups) had the McFarlane flap raised and CAP, L-NAME, and PRP substances tested through a single dose subcutaneous injection. The control group had only a saline solution injected. To the best of our knowledge, this is the first study that evaluated a CAP activated solution through injection on flaps. The flap survival rate was determined by clinical examination (photography documented), hematology, thermography, and anatomopathological tests. The image digital analysis performed on the flaps showed that the necrosis area (control—49.64%) was significantly lower for the groups with the three investigated solutions: CAP (14.47%), L-NAME (18.2%), and PRP (23.85%). Thermography exploration revealed less ischemia than the control group on the CAP, L-NAME, and PRP groups as well. Anatomopathological data noted the best degree of angiogenesis on the CAP group, with similar findings on the L-NAME and PRP treated flaps. The blood work did not indicate infection or a strong inflammatory process in any of the subjects. Overall, the study shows that the CAP activated solution has a similar (better) impact on the necrosis rate (compared with other solutions with known effects) when injected on the modified dorsal rat skin flap, and on top of that it can be obtained fast, in unlimited quantities, non-invasively, and through a standardized process.

scholarly journals Thiocoumarin Caged Nucleotides: Synthetic Access and Their Photophysical Properties

Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5325
Author(s):  
Jiahui Ma ◽  
Alexander Ripp ◽  
Daniel Wassy ◽  
Tobias Dürr ◽  
Danye Qiu ◽  
...  
Keyword(s):  
Controlled Release ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Uv Light ◽  
Adenine Nucleotides ◽  
Photophysical Properties ◽  
Quantum Yields ◽  
Spatio Temporal

Photocages have been successfully applied in cellular signaling studies for the controlled release of metabolites with high spatio-temporal resolution. Commonly, coumarin photocages are activated by UV light and the quantum yields of uncaging are relatively low, which can limit their applications in vivo. Here, syntheses, the determination of the photophysical properties, and quantum chemical calculations of 7-diethylamino-4-hydroxymethyl-thiocoumarin (thio-DEACM) and caged adenine nucleotides are reported and compared to the widely used 7-diethylamino-4-hydroxymethyl-coumarin (DEACM) caging group. In this comparison, thio-DEACM stands out as a phosphate cage with improved photophysical properties, such as red-shifted absorption and significantly faster photolysis kinetics.

Facilitated migration of cells from a transected peripheral nerve over collagen fibers: in vivo observations

1989 ◽  
Vol 47 ◽  
pp. 888-889
Author(s):  
Arthur J. Wasserman ◽  
Azam Rizvi ◽  
George Zazanis ◽  
Frederick H. Silver
Keyword(s):  
Sciatic Nerve ◽  
Peripheral Nerve ◽  
Collagen Gel ◽  
Collagen Fibers ◽  
Control Group ◽  
Guide Tube ◽  
Sprague Dawley ◽  
Silicone Tube ◽  
Thin Sections

In cases of peripheral nerve damage the gap between proximal and distal stumps can be closed by suturing the ends together, using a nerve graft, or by nerve tubulization. Suturing allows regeneration but does not prevent formation of painful neuromas which adhere to adjacent tissues. Autografts are not reported to be as good as tubulization and require a second surgical site with additional risks and complications. Tubulization involves implanting a nerve guide tube that will provide a stable environment for axon proliferation while simultaneously preventing formation of fibrous scar tissue. Supplementing tubes with a collagen gel or collagen plus extracellular matrix factors is reported to increase axon proliferation when compared to controls. But there is no information regarding the use of collagen fibers to guide nerve cell migration through a tube. This communication reports ultrastructural observations on rat sciatic nerve regeneration through a silicone nerve stent containing crosslinked collagen fibers.Collagen fibers were prepared as described previously. The fibers were threaded through a silicone tube to form a central plug. One cm segments of sciatic nerve were excised from Sprague Dawley rats. A control group of rats received a silicone tube implant without collagen while an experimental group received the silicone tube containing a collagen fiber plug. At 4 and 6 weeks postoperatively, the implants were removed and fixed in 2.5% glutaraldehyde buffered by 0.1 M cacodylate containing 1.5 mM CaCl2 and balanced by 0.1 M sucrose. The explants were post-fixed in 1% OSO4, block stained in 1% uranyl acetate, dehydrated and embedded in Epon. Axons were counted on montages prepared at a total magnification of 1700x. Montages were viewed through a dissecting microscope. Thin sections were sampled from the proximal, middle and distal regions of regenerating sciatic plugs.

A Molecular Approach to Immunoscintigraphy: A Study of the T-Antigen Conformation on the Surface of Tumors

1987 ◽  
Vol 26 (01) ◽  
pp. 1-6 ◽  
Author(s):  
S. Selvaraj ◽  
M. R. Suresh ◽  
G. McLean ◽  
D. Willans ◽  
C. Turner ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Tumor Cell ◽  
T Antigen ◽  
Human Carcinomas ◽  
Animal Tumor ◽  
Synthetic Antigens

The role of glycoconjugates in tumor cell differentiation has been well documented. We have examined the expression of the two anomers of the Thomsen-Friedenreich antigen on the surface of human, canine and murine tumor cell membranes both in vitro and in vivo. This has been accomplished through the synthesis of the disaccharide terminal residues in both a and ß configuration. Both entities were used to generate murine monoclonal antibodies which recognized the carbohydrate determinants. The determination of fine specificities of these antibodies was effected by means of cellular uptake, immunohistopathology and immunoscintigraphy. Examination of pathological specimens of human and canine tumor tissue indicated that the expressed antigen was in the β configuration. More than 89% of all human carcinomas tested expressed the antigen in the above anomeric form. The combination of synthetic antigens and monoclonal antibodies raised specifically against them provide us with invaluable tools for the study of tumor marker expression in humans and their respective animal tumor models.

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