scholarly journals Evaluation of in Vivo Response of Three Biphasic Scaffolds for Osteochondral Tissue Regeneration in a Sheep Model

2019 ◽  
Vol 6 (4) ◽  
pp. 90 ◽  
Author(s):  
Alberto M. Crovace ◽  
Alessia Di Giancamillo ◽  
Francesca Gervaso ◽  
Laura Mangiavini ◽  
Davide Zani ◽  
...  
Keyword(s):  
Tissue Regeneration ◽  
Collagen Matrix ◽  
Control Group ◽  
The Novel ◽  
Sheep Model ◽  
Complete Restoration ◽  
Different Types ◽  
Ct Analysis ◽  
Reparative Process

Osteochondral defects are a common problem in both human medicine and veterinary practice although with important limits concerning the cartilaginous tissue regeneration. Interest in the subchondral bone has grown, as it is now considered a key element in the osteochondral defect healing. The aim of this work was to generate and to evaluate the architecture of three cell-free scaffolds made of collagen, magnesium/hydroxyapatite and collagen hydroxyapatite/wollastonite to be implanted in a sheep animal model. Scaffolds were designed in a bilayer configuration and a novel “Honey” configuration, where columns of hydroxyapatite were inserted within the collagen matrix. The use of different types of scaffolds allowed us to identify the best scaffold in terms of integration and tissue regeneration. The animals included were divided into four groups: three were treated using different types of scaffold while one was left untreated and represented the control group. Evaluations were made at 3 months through CT analysis. The novel “Honey” configuration of the scaffold with hydroxyapatite seems to allow for a better reparative process, although we are still far from obtaining a complete restoration of the defect at this time point of follow-up.

scholarly journals A Metabolomic Approach for the In Vivo Study of Gold Nanospheres and Nanostars after a Single-Dose Intravenous Administration to Wistar Rats

Nanomaterials ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1606 ◽  
Author(s):  
Enea ◽  
Araújo ◽  
Almeida ◽  
Soares ◽  
Gonçalves-Monteiro ◽  
...  
Keyword(s):  
Single Dose ◽  
Intravenous Administration ◽  
Wistar Rats ◽  
Metabolic Effects ◽  
Control Group ◽  
Gold Nanospheres ◽  
Gold Nanostars ◽  
Different Types ◽  
Metabolomic Approach

Gold nanoparticles (AuNPs) are promising nanoplatforms for drug therapy, diagnostic and imaging. However, biological comparison studies for different types of AuNPs fail in consistency due to the lack of sensitive methods to detect subtle differences in the expression of toxicity. Therefore, innovative and sensitive approaches such as metabolomics are much needed to discriminate toxicity, specially at low doses. The current work aims to compare the in vivo toxicological effects of gold nanospheres versus gold nanostars (of similar ~40 nm diameter and coated with 11-mercaptoundecanoic acid) 24 h after an intravenous administration of a single dose (1.33 × 1011 AuNPs/kg) to Wistar rats. The biodistribution of both types of AuNPs was determined by graphite furnace atomic absorption spectroscopy. The metabolic effects of the AuNPs on their main target organ, the liver, were analyzed using a GC-MS-based metabolomic approach. Conventional toxicological endpoints, including the levels of ATP and reduced and oxidized glutathione, were also investigated. The results show that AuNPs preferentially accumulate in the liver and, to a lesser extent, in the spleen and lungs. In other organs (kidney, heart, brain), Au content was below the limit of quantification. Reduced glutathione levels increased for both nanospheres and nanostars in the liver, but ATP levels were unaltered. Multivariate analysis showed a good discrimination between the two types of AuNPs (sphere- versus star-shaped nanoparticles) and compared to control group. The metabolic pathways involved in the discrimination were associated with the metabolism of fatty acids, pyrimidine and purine, arachidonic acid, biotin, glycine and synthesis of amino acids. In conclusion, the biodistribution, toxicological, and metabolic profiles of gold nanospheres and gold nanostars were described. Metabolomics proved to be a very useful tool for the comparative study of different types of AuNPs and raised awareness about the pathways associated to their distinct biological effects.

Hybrid Chitosan Membranes Tested in Sheep for Guided Tissue Regeneration

2007 ◽  
Vol 361-363 ◽  
pp. 1265-1268 ◽  
Author(s):  
P.P. Cortez ◽  
Yuki Shirosaki ◽  
C.M. Botelho ◽  
M.J. Simões ◽  
F. Gartner ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Tissue Regeneration ◽  
Chitosan Solution ◽  
Clinical Applications ◽  
Histological Evaluation ◽  
Sheep Model ◽  
The Third ◽  
Chitosan Membranes

Previous in vitro studies confirmed an improved cytocompatibility of chitosan-silicate hybrid membranes over chitosan membranes. The main goal of this study was to assess the in vivo histocompatibility of both membranes through subcutaneous implantations at different time periods, 1 week, 1, 2 and 3 months, using a sheep model. Chitosan membranes elicited an exuberant inflammatory response and were consequently rejected. The hybrid chitosan membranes were not rejected and the degree of inflammatory response decreased gradually until the third month of implantation. Histological evaluation also showed that these membranes can be resorbed in vivo. This study demonstrates that the incorporation of silicate into the chitosan solution improves its histocompatibility, indicating that the hybrid chitosan-silicate membranes are suitable candidates to be used in clinical applications.

scholarly journals Evaluation of miniscrew stability using an automatic embedding auxiliary skeletal anchorage device

2018 ◽  
Vol 89 (1) ◽  
pp. 47-53
Author(s):  
Yasuhiko Oga ◽  
Hiroshi Tomonari ◽  
Sangho Kwon ◽  
Takaharu Kuninori ◽  
Takakazu Yagi ◽  
...  
Keyword(s):  
Cortical Bone ◽  
Lateral Displacement ◽  
Control Group ◽  
The Novel ◽  
Micro Computed Tomography ◽  
Bone Thickness ◽  
Retention Force ◽  
Implantation Depth ◽  
Auxiliary Device

ABSTRACT Objective: To clarify the in vivo effect of an automatic embedding device on miniscrew stability. Materials and Methods: 42 miniscrews were implanted into rabbit femurs. The miniscrews with the novel auxiliary device formed the auxiliary group (n = 11 at 4 weeks; n = 11 at 8 weeks) and the miniscrews without the auxiliary device formed the nonauxiliary control group (n = 9 at 4 weeks; n = 11 at 8 weeks). Cortical bone thickness, distance from the cortical bone surface to the miniscrew head, and implantation depth of the spike were measured using micro-computed tomography. The mechanical retention force was evaluated by measuring the displacement of the miniscrew head after it was loaded perpendicular to its long axis. In the lateral displacement test, effects of the auxiliary (with vs without auxiliary), and time (4 vs 8 weeks) were assessed using the Brunner–Langer nonparametric analysis of longitudinal data in factorial experiments. Results: The mean implantation depth of the spike in the auxiliary group at 4 and 8 weeks was 0.28 mm (median: 0.33; SD: 0.12) and 0.37 mm (median: 0.33; SD: 0.19), respectively. The retention force was approximately 2.0 to 2.8 and 1.6 to 1.8 times greater in the auxiliary group than in the nonauxiliary group at 4 and 8 weeks, respectively. Conclusions: The auxiliary device improved the mechanical retention force without the need to increase miniscrew length or diameter. This may enable the safe use of miniscrews in difficult areas.

Characterization of the novel OXA-213-like β-lactamase OXA-822 from Acinetobacter calcoaceticus

2020 ◽  
Author(s):  
Manuela Tietgen ◽  
Laura Leukert ◽  
Julian Sommer ◽  
Jan S Kramer ◽  
Steffen Brunst ◽  
...  
Keyword(s):  
Galleria Mellonella ◽  
Sequence Similarity ◽  
Acinetobacter Calcoaceticus ◽  
Amino Acid Sequence Similarity ◽  
Control Group ◽  
Infection Model ◽  
The Novel ◽  
High Turnover

Abstract Objectives This study analysed the novel carbapenem-hydrolysing class D β-lactamase OXA-822 identified in the clinical Acinetobacter calcoaceticus isolate AC_2117. Methods WGS was employed for identification of β-lactamases. Micro-broth dilution was used for evaluation of antibiotic susceptibility of AC_2117 and transformants containing blaOXA-822. After heterologous purification of OXA-822, OXA-359 and OXA-213, enzyme kinetics were determined using spectrometry. The effect of OXA-822 upon meropenem treatment was analysed in the Galleria mellonella in vivo infection model. Results OXA-822 is a member of the intrinsic OXA-213-like family found in A. calcoaceticus and Acinetobacter pittii. Amino acid sequence similarity to the nearest related OXA-359 was 97%. Production of OXA-822, OXA-359 and OXA-213 in Acinetobacter baumannii ATCC® 19606T resulted in elevated MICs for carbapenems (up to 16-fold). Penicillinase activity of the purified OXA-822 revealed high KM values, in the millimolar range, combined with high turnover numbers. OXA-822 showed the highest affinity to carbapenems, but affinity to imipenem was ∼10-fold lower compared with other carbapenems. Molecular modelling revealed that imipenem does not interact with a negatively charged side chain of OXA-822, as doripenem does, leading to the lower affinity. Presence of OXA-822 decreased survival of infected Galleria mellonella larvae after treatment with meropenem. Only 52.7% ± 7.7% of the larvae survived after 24 h compared with 90.9% ± 3.7% survival in the control group. Conclusions The novel OXA-822 from a clinical A. calcoaceticus isolate displayed penicillinase and carbapenemase activity in vitro, elevated MICs in different species and decreased carbapenem susceptibility in A. baumannii in vivo.

Effects of Variability of Practice in a Movement-Education Program on Motor Skill Performance

1981 ◽  
Vol 52 (3) ◽  
pp. 779-784 ◽  
Author(s):  
Jane B. Moore ◽  
T. Gilmour Reeve ◽  
Becky Pissanos
Keyword(s):  
Direct Method ◽  
Kindergarten Children ◽  
Control Group ◽  
The Novel ◽  
Movement Education ◽  
Skill Performance ◽  
Throwing Accuracy ◽  
Different Types ◽  
Overhand Throwing ◽  
Different Levels

The study investigated the effects of the direct and exploration methods of teaching on the overhand throwing performance of kindergarten children. Variable throwing practice was provided in the exploration method by allowing children to throw 5 different types of balls at a variety of targets. Children given the direct method threw only one type of ball and received specific instruction and demonstrations. Throwing for distance and throwing accuracy were measured on pre- and posttests. A novel throwing task was administered on the posttest to measure skill transfer. The experimental groups received instruction three times per week for 4 wk. in throwing while a control group received no instruction. Significant sex differences in throws were found for distance and accuracy. Analysis of data from the novel task gave no significant effects. The two methods of teaching did not produce different levels of throwing skill.

scholarly journals Novel nanotech antioxidant cocktail prevents medical diagnostic procedures ionizing radiation effects

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Miguel Gorenberg ◽  
Abed Agbarya ◽  
David Groshar ◽  
Ilya Volovik ◽  
Ofir Avitan ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Protective Effect ◽  
Radiation Effects ◽  
Diagnostic Procedures ◽  
Peripheral Blood Lymphocytes ◽  
Dna Lesions ◽  
Control Group ◽  
The Novel ◽  
Significant Difference

AbstractIonizing radiation (IR) exposure results in oxidative damage causing cytotoxic and genotoxic effects. Double-strand breaks (DSBs) are considered the most significant DNA lesions induced by ionizing radiation. The present study evaluates the radio protective effect of a novel antioxidant cocktail through quantification of DSB in peripheral blood lymphocytes (PBL) in vivo. The study included 16 consecutive patients who were divided into 2 groups, 6 patients received the novel antioxidant cocktail and 10 control patients. Blood samples were drawn from the patients undergoing bone scan, before the injection of the 99mTc MDP tracer and 2 h after the injection. Quantification of the IR damage was done by Immunofluorescence analysis of the phosphorylated histone, γ-H2AX, used to monitor DSB induction and repair in PBL. The radiation effect of the control group was measured by 2 variables, the average DBSs foci per nucleus and the percent of the DSB bearing cells in PBL. The findings showed a significant increase in the DSBs after isotope injection with an average increment of 0.29 ± 0.13 of foci/nucleus and 17.07% ± 7.68 more DSB bearing cells (p < 0.05). The cocktail treated group showed a lower difference average of − 2.79% ± 6.13 DSB bearing cells. A paired t-test revealed a significant difference between the groups (p < 0.005) confirming the cocktail’s protective effect. The novel anti-oxidant treatment decreases the oxidative stress-induced DNA damage and can be considered as a preventative treatment before radiation exposure.

Fibrin-Reinforced Collagen Matrix Enhances Tissue Regeneration and Angiogenesis

2005 ◽  
Vol 288-289 ◽  
pp. 257-260
Author(s):  
Dong Lim Seol ◽  
Won Hee Jang ◽  
Sung Jae Lee ◽  
Young Il Yang
Keyword(s):  
Tissue Regeneration ◽  
Nude Mice ◽  
Functional Integration ◽  
Collagen Matrix ◽  
Dermal Fibroblasts ◽  
Surrounding Tissue ◽  
Human Dermal Fibroblasts ◽  
Collagen Matrices

The goal of this study was to investigate effects of fibrin reinforcement of collagen sponges on fibroblasts-mediated contraction and in vivo tissue regeneration, especially angiogenesis. Human dermal fibroblasts (HDFs)-populated collagen sponges reinforced with or without fibrin were cultivated via the free-floating method in vitro. They were then evaluated using xenogeneic implantation into nude mice. The HDFs-populated collagen sponges reinforced with fibrin exhibited significantly decreased HDFs-mediated contraction in vitro (p<0.05). Microvascular and cellular densities of the collagen sponges were significantly higher with fibrin than without (p<0.01). Cell ingrowths, neovascularization, and deposition of ECM matrix were more evenly distributed in the fibrin-reinforced collagen matrices. The results demonstrated that fibrin reinforcement of porous collagen sponges can reduce cell-mediated contraction in vitro while enhancing functional integration with surrounding tissue in vivo.

scholarly journals Effect of Bio-Oss® Collagen and Collagen Matrix on Bone Formation

2010 ◽  
Vol 4 (1) ◽  
pp. 71-76 ◽  
Author(s):  
R.W.K Wong ◽  
A.B.M Rabie
Keyword(s):  
Bone Formation ◽  
Collagen Matrix ◽  
Negative Control Group ◽  
Positive Control ◽  
Negative Control ◽  
Parietal Bone ◽  
Control Group ◽  
Graft Material ◽  
New Bone Formation

Objective: to compare the amount of new bone produced by Bio-Oss® Collagen to that produced by collagen matrix in vivo. Method: eighteen bone defects, 5mm by 10mm were created in the parietal bone of 9 New Zealand White rabbits. 6 defects were grafted with Bio-Oss® Collagen. 6 defects were grafted with collagen matrix alone (positive control) and 6 were left empty (negative control). Animals were killed on day 14 and the defects were dissected and prepared for histological assessment. Quantitative analysis of new bone formation was made on 100 sections (50 sections for each group) using image analysis. Results: A total of 339% more new bone was present in defects grafted with Bio-Oss® Collagen than those grafted with collagen matrix (positive control). No bone was formed in the negative control group. Conclusion: Bio-Oss® Collagen has the effect of stimulating new bone formation locally compared with collagen matrix in vivo. Bio-Oss® Collagen may be utilized as a bone graft material.

scholarly journals Extracorporeal Shock Wave Rebuilt Subchondral Bone In Vivo and Activated Wnt5a/Ca2+ Signaling In Vitro

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Lai Yu ◽  
Shuitao Liu ◽  
Zhe Zhao ◽  
Lin Xia ◽  
Haochong Zhang ◽  
...  
Keyword(s):  
Shock Wave ◽  
Subchondral Bone ◽  
Control Group ◽  
Extracorporeal Shock Wave ◽  
Tibial Condyle ◽  
Bone Changes ◽  
Marrow Mesenchymal Stem Cells ◽  
Ct Analysis

Background. This study aimed to identify the optimal extracorporeal shock wave (ESW) intensity and to investigate its effect on subchondral bone rebuilt in vivo and Wnt5a/Ca2+ signaling in vitro using an osteoarthritis (OA) rat model and bone marrow mesenchymal stem cells (BMMSCs), respectively. Methods. OA rats treated with (OA + ESW group) or without (OA group) ESW (n=12/group) were compared with healthy controls (control group, n=12). Gait patterns and subchondral trabecular bone changes were measured. Western blot and quantitative real-time polymerase chain reaction detected protein expression and gene transcription, respectively. Results. The gait disturbances of OA + ESW group were significantly improved compared with the OA group at 6th and 8th weeks. The micro-CT analysis indicated that the BMD, BSV/BV, BV/TV, Tr.S, and Tr.Th are significantly different between OA group and OA + ESW group. Expression of Wnt5a was increased rapidly after ESW treatment at 0.6 bar and peaked after 30 min. Conclusions. ESW were positive for bone remodeling in joint tibial condyle subchondral bone of OA rat. ESW prevented histological changes in OA and prevented gait disturbance associated with OA progression. Optimal intensity of ESW induced changes in BMMSCs via activation of the Wnt5a/Ca2+ signaling pathway.

scholarly journals PLASTY OF DURA MATER DEFECTS BY COLLAGEN IMPLANTS USING NON-SUTURE CONTACT DIRECT BONDING METHOD

2017 ◽  
Vol 176 (2) ◽  
pp. 70-76
Author(s):  
D. E. Alekseev ◽  
D. V. Svistov ◽  
D. E. Matsko ◽  
E. D. Alekseev
Keyword(s):  
Dura Mater ◽  
Collagen Matrix ◽  
Laboratory Animals ◽  
Control Group ◽  
Meaningful Difference ◽  
Collagen Matrices ◽  
Fourth Group ◽  
Bonding Method ◽  
Dural Defects

OBJECTIVE. The study investigated and compared the efficacy of plasty of dura mater using different collagen materials in the experiment. MATERIALS AND METHODS. The experimental study in vivo was carried out on 60 laboratory animals. Rabbits were divided into 4 groups after performing the craniotomy and dura mater opening. It depended on the material used for plasty of dural defects such as Duraform, Lyostypt and Russian prototype of collagen matrix for dural grafting. The fourth group was the control group. The presence and severity of meningo-cerebral adhesion, histological and immunological researches of duraplasty areas were performed after the experiment. RESULTS. The severity of meningo-cerebral adhesion was significantly higher in control group, but there wasn’t noted any meaningful difference in the groups with different collagen matrices. These groups had similar histological and immunohistochemical features. CONCLUSIONS. An application of collagen matrix improved the results of duraplasty and prevented formation of meningo-cerebral adhesions in the experiment. This data predict the high clinical efficacy of the method.

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