scholarly journals TCP-Fluorapatite Composite Scaffolds: Mechanical Characterization and In Vitro/In Vivo Testing

2017 ◽  
Author(s):  
Achouak Elghazel ◽  
Rym Taktak ◽  
Jamel Bouaziz ◽  
Slim Charfi ◽  
Hassib Keskes
Keyword(s):  
Mechanical Characterization ◽  
Composite Scaffolds ◽  
In Vivo Testing

Aspiration Revisited: Prospective Evaluation of a Physiologically Pressurized Model With Animal Correlation and Broader Applicability to Filler Complications

2021 ◽  
Author(s):  
Hyoung-Jin Moon ◽  
Won Lee ◽  
Ji-Soo Kim ◽  
Eun-Jung Yang ◽  
Hema Sundaram
Keyword(s):  
Normal Saline ◽  
False Negative ◽  
Vascular Complications ◽  
Filler Injection ◽  
Negative Results ◽  
Needle Position ◽  
False Negative Results ◽  
In Vivo Testing

Abstract Background Aspiration testing before filler injection is controversial. Some believe that aspiration can help prevent inadvertent intravascular injection, while others cite false-negative results and question its value given that the needle position always changes somewhat during injection procedures. Objectives To test the relation of false-negative results to the viscosity of the material within the needle lumen and determine whether a less viscous material within the needle lumen could decrease the incidence of false-negative results. Methods In vitro aspiration tests were performed using 30-G and 27-G needle gauges, two cross-linked hyaluronic acid fillers, normal saline bags pressurized at 140 and 10 mmHg to mimic human arterial and venous pressures, and three needle lumen conditions (normal saline, air, and filler). Testing was repeated three times under each study condition (72 tests in total). For in vivo correlation, aspiration tests were performed on femoral arteries and central auricular veins in three rabbits (4–5 aspirations per site, 48 tests in total). Results In vitro and in vivo testing using 30-G needles containing filler both showed false-negative results on aspiration testing. In vitro and in vivo testing using needles containing saline or air showed positive findings. Conclusions False-negative results from aspiration testing may be reduced by pre-filling the needle lumen with saline rather than a filler. The pressurized system may help overcome challenges of animal models with intravascular pressures significantly different from those of humans. The adaptability of this system to mimic various vessel pressures may facilitate physiologically relevant studies of vascular complications.

scholarly journals Effective decellularisation of human saphenous veins for biocompatible arterial tissue engineering applications: Bench optimisation and feasibility in vivo testing

2021 ◽  
Vol 12 ◽  
pp. 204173142098752
Author(s):  
Nadiah S Sulaiman ◽  
Andrew R Bond ◽  
Vito D Bruno ◽  
John Joseph ◽  
Jason L Johnson ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Mechanical Strength ◽  
Vascular Tissue ◽  
Sodium Dodecyl ◽  
Host Cells ◽  
Replacement Model ◽  
In Vivo Testing ◽  
Vascular Scaffolds

Human saphenous vein (hSV) and synthetic grafts are commonly used conduits in vascular grafting, despite high failure rates. Decellularising hSVs (D-hSVs) to produce vascular scaffolds might be an effective alternative. We assessed the effectiveness of a detergent-based method using 0% to 1% sodium dodecyl sulphate (SDS) to decellularise hSV. Decellularisation effectiveness was measured in vitro by nuclear counting, DNA content, residual cell viability, extracellular matrix integrity and mechanical strength. Cytotoxicity was assessed on human and porcine cells. The most effective SDS concentration was used to prepare D-hSV grafts that underwent preliminary in vivo testing using a porcine carotid artery replacement model. Effective decellularisation was achieved with 0.01% SDS, and D-hSVs were biocompatible after seeding. In vivo xeno-transplantation confirmed excellent mechanical strength and biocompatibility with recruitment of host cells without mechanical failure, and a 50% patency rate at 4-weeks. We have developed a simple biocompatible methodology to effectively decellularise hSVs. This could enhance vascular tissue engineering toward future clinical applications.

scholarly journals DDEL-12. NANOPARTICLE DELIVERY OF DOXORUBICIN FOR THE TREATMENT OF DIFFUSE INTRINSIC PONTINE GLIOMA (DIPG)

2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii286-iii286
Author(s):  
Caitlin Ung ◽  
Maria Tsoli ◽  
Jie Liu ◽  
Domenico Cassano ◽  
Dannielle Upton ◽  
...  
Keyword(s):  
Treatment Strategies ◽  
Pediatric Brain Tumors ◽  
Diffuse Intrinsic Pontine Glioma ◽  
Confocal Imaging ◽  
Cell Content ◽  
Potent Effect ◽  
Orthotopic Mouse Model ◽  
In Vivo Testing

Abstract DIPGs are the most aggressive pediatric brain tumors. Currently, the only treatment is irradiation but due to its palliative nature patients die within 12 months. Effective delivery of chemotherapy across the blood-brain barrier (BBB) has been a key challenge for the eradication of this disease. We have developed a novel gold nanoparticle functionalised with human serum albumin (Au-NP, 98.8 ±19 nm) for the delivery of doxorubicin. In this study, we evaluated the cytotoxic efficacy of doxorubicin delivered through gold nanoparticles (Au-NP-Dox). We found that DIPG neurospheres were equally sensitive to doxorubicin and Au-NP-Dox (at equimolar concentration) by alamar blue assay. Colony formation assays demonstrated a significantly more potent effect of Au-NP-Dox compared to doxorubicin alone, while the Au-NP had no effect. Furthermore, western blot analysis indicated increased apoptotic markers cleaved Parp, caspase 3/7 and phosphorylated H2AX in Au-NP-Dox treated DIPG neurospheres. Live cell content and confocal imaging demonstrated significantly higher uptake of Au-NP-Dox compared to doxorubicin alone. Treatment of a DIPG orthotopic mouse model with Au-NP-Dox showed no signs of toxicity with stable weights being maintained during treatment. However, in contrast to the above in vitro findings the in vivo study showed no anti-tumor effect possibly due to poor penetration of Au-NP-Dox into the brain. We are currently evaluating whether efficacy can be improved using measures to open the BBB transiently. This study highlights the need for rigorous in vivo testing of new treatment strategies before clinical translation to reduce the risk of administration of ineffective treatments.

In vitro and in vivo testing and correlation for oral controlled/ modified release dosage forms. report of the 2nd workshop held December 1988, Washington, DC. U.S.A.

1990 ◽  
Vol 14 (1) ◽  
pp. 95-106 ◽  
Author(s):  
Jerome P. Skelly ◽  
Gordon L. Amidon ◽  
William H. Barr ◽  
Leslie Z. Benet ◽  
James E. Carter ◽  
...  
Keyword(s):  
Dosage Forms ◽  
Washington Dc ◽  
Modified Release ◽  
In Vivo Testing

scholarly journals A composite scaffold of Wharton’s jelly and chondroitin sulphate loaded with human umbilical cord mesenchymal stem cells repairs articular cartilage defects in rat knee

2021 ◽  
Vol 32 (4) ◽  
Author(s):  
Zhong Li ◽  
Yikang Bi ◽  
Qi Wu ◽  
Chao Chen ◽  
Lu Zhou ◽  
...  
Keyword(s):  
Stem Cells ◽  
Articular Cartilage ◽  
Composite Scaffold ◽  
Biomechanical Properties ◽  
Cartilage Defects ◽  
Human Umbilical Cord ◽  
Composite Scaffolds ◽  
Articular Cartilage Defects

AbstractTo evaluate the performance of a composite scaffold of Wharton’s jelly (WJ) and chondroitin sulfate (CS) and the effect of the composite scaffold loaded with human umbilical cord mesenchymal stem cells (hUCMSCs) in repairing articular cartilage defects, two experiments were carried out. The in vitro experiments involved identification of the hUCMSCs, construction of the biomimetic composite scaffolds by the physical and chemical crosslinking of WJ and CS, and testing of the biomechanical properties of both the composite scaffold and the WJ scaffold. In the in vivo experiments, composite scaffolds loaded with hUCMSCs and WJ scaffolds loaded with hUCMSCs were applied to repair articular cartilage defects in the rat knee. Moreover, their repair effects were evaluated by the unaided eye, histological observations, and the immunogenicity of scaffolds and hUCMSCs. We found that in vitro, the Young’s modulus of the composite scaffold (WJ-CS) was higher than that of the WJ scaffold. In vivo, the composite scaffold loaded with hUCMSCs repaired rat cartilage defects better than did the WJ scaffold loaded with hUCMSCs. Both the scaffold and hUCMSCs showed low immunogenicity. These results demonstrate that the in vitro construction of a human-derived WJ-CS composite scaffold enhances the biomechanical properties of WJ and that the repair of knee cartilage defects in rats is better with the composite scaffold than with the single WJ scaffold if the scaffold is loaded with hUCMSCs.

scholarly journals Coagulation under Mild Hypothermia Assessed by Thromboelastometry

2021 ◽  
pp. 1-7
Author(s):  
Tobias Nitschke ◽  
Philipp Groene ◽  
Alice-Christin Acevedo ◽  
Tobias Kammerer ◽  
Simon T. Schäfer
Keyword(s):  
Mild Hypothermia ◽  
Onset Time ◽  
Rotational Thromboelastometry ◽  
Lysis Time ◽  
Sample Data ◽  
In Vivo Testing ◽  
Fibrinolytic Capacity ◽  
Clot Formation Time

<b><i>Introduction:</i></b> While previous studies have shown a significant impact of extreme hypo- and hyperthermia on coagulation, effects of much more frequently occurring perioperative mild hypothermia are largely unknown. This study therefore aimed to analyze the effects of mild hypothermia using rotational thromboelastometry in vitro. <b><i>Materials and Methods:</i></b> Twelve healthy volunteers were included in this study. Standard thromboelastometric tests (EXTEM, INTEM, FIBTEM) were used to evaluate coagulation in vitro at 39, 37, 35.5, 35, and 33°C. Beyond standard thromboelastometric tests, we also evaluated the effects of mild hypothermia on the TPA-test (ClotPro, Enicor GmbH, Munich, Germany), a new test which aims to detect fibrinolytic capacity by adding tissue plasminogen activator to the sample. Data are presented as the median with 25/75th percentiles. <b><i>Results:</i></b> Extrinsically activated coagulation (measured by EXTEM) showed a significant increase in clot formation time (CFT; 37°C: 90 s [81/105] vs. 35°C: 109 s [99/126]; <i>p</i> = 0.0002), while maximum clot firmness (MCF) was not significantly reduced. Intrinsically activated coagulation (measured by INTEM) also showed a significant increase in CFT (37°C: 80 s [72/88] vs. 35°C: 94 s [86/109]; <i>p</i> = 0.0002) without significant effects on MCF. Mild hypothermia significantly increased both the lysis onset time (136 s [132/151; 37°C] vs. 162 s [141/228; 35°C], <i>p</i> = 0.0223) and lysis time (208 s [184/297; 37°C] vs. 249 s [215/358; 35°C]; <i>p</i> = 0.0259). <b><i>Conclusion:</i></b> This demonstrates that even under mild hypothermia coagulation is significantly altered in vitro. Perioperative temperature monitoring and management are greatly important and can help to prevent mild hypothermia and its adverse effects. Further investigation and in vivo testing of coagulation under mild hypothermia is needed.

A Comprehensive Study of Osteogenic Calcium Phosphate Silicate Cement: Material Characterization and In Vitro/In Vivo Testing

2015 ◽  
Vol 5 (4) ◽  
pp. 457-466 ◽  
Author(s):  
Tianxing Gong ◽  
Zhiqin Wang ◽  
Yixi Zhang ◽  
Yubiao Zhang ◽  
Mingxiao Hou ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Material Characterization ◽  
Cement Material ◽  
Phosphate Silicate ◽  
In Vivo Testing ◽  
Comprehensive Study

Antimalaria Activity of Cassia spectabilis DC Leaf and Its Inhibition Effect in Heme Detoxification

2020 ◽  
Author(s):  
Wiwied - Ekasari ◽  
Dewi Resty Basuki ◽  
Heny - Arwati ◽  
Tutik Sri Wahy
Keyword(s):  
Antimalarial Activity ◽  
Ethanol Extract ◽  
Ic50 Value ◽  
Cassia Spectabilis ◽  
In Vivo Testing ◽  
Chloroquine Diphosphate ◽  
Better Than

Abstract Background In previous studies, Cassia spectabilis DC leaf has shown a good antimalarial activity. Therefore, this study is a follow-up study of leaf activity and mechanism of C. spectabilis DC as an antimalarial. Methods In vitro antimalarial activity testing using P. falciparum which was done with bioassay guide isolation in order to obtain the active compound. In vivo testing towards infected P. berghei mice was conducted to determine the effects of antimalarial prophylaxis and antimalarial activity in combination with artesunate. Whereas, heme detoxification inhibition testing as one of the antimalarial mechanisms was carried out using the Basilico method. Results The results showed that active antimalarial isolate obtained from C. spectabilis DC leaf had a structural pattern that was identical to (-)-7-hydroxyspectaline. Prophylactic test on infected P. berghei mice obtained the highest dose of inhibition percentage of 90% ethanol extract of C. spectabilis DC leaf was 68.61% while positive (doxycycline) control at 100 mg kg-1 was 73.54%. In antimalarial testing in combination with artesunate, it was found that administering 150 mg kg-1 (three times a day) of C. spectabilis DC (D0 − D2) + artesunate (D2) was better than the standard combination of amodiaquine + artesunate with 99.18% and 92.88% inhibition percentage. For the inhibitory activity of heme detoxification from ethanol extract 90%, C. spectabilis DC leaf had IC50 value of 0.375 mg mL-1 which was better than chloroquine diphosphate. Conclusion These results showed that C. spectabilis DC leaves possesses potent antimalarial activity and may offer a potential agent for effective and affordable antimalarial phytomedicine.

scholarly journals Force spectroscopy-based simultaneous topographical and mechanical characterization to study polymer-to-polymer interactions in coated alginate microspheres

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Maria Virumbrales-Muñoz ◽  
Edorta Santos-Vizcaino ◽  
Laura Paz ◽  
Amparo Maria Gallardo-Moreno ◽  
Gorka Orive ◽  
...  
Keyword(s):  
Cross Correlation ◽  
Mechanical Characterization ◽  
Force Spectroscopy ◽  
Covalent Bonding ◽  
Design Rationale ◽  
Polymer Interactions ◽  
First Time ◽  
Hydrogel Microspheres

AbstractCell-laden hydrogel microspheres have shown encouraging outcomes in the fields of drug delivery, tissue engineering or regenerative medicine. Beyond the classical single coating with polycations, many other different coating designs have been reported with the aim of improving mechanical properties and in vivo performance of the microspheres. Among the most common strategies are the inclusion of additional polycation coatings and the covalent bonding of the semi-permeable membranes with biocompatible crosslinkers such as genipin. However, it remains challenging to characterize the effects of the interactions between the polycations and the hydrogel microspheres over time in vitro. Here we use a force spectroscopy-based simultaneous topographical and mechanical characterization to study polymer-to-polymer interactions in alginate microspheres with different coating designs, maintaining the hydrogels in liquid. In addition to classical topography parameters, we explored, for the first time, the evolution of peak/valley features along the z axis via thresholding analysis and the cross-correlation between topography and stiffness profiles with resolution down to tens of nanometers. Thus, we demonstrated the importance of genipin crosslinking to avoid membrane detachment in alginate microspheres with double polycation coatings. Overall, this methodology could improve hydrogel design rationale and expedite in vitro characterization, therefore facilitating clinical translation of hydrogel-based technologies.

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