Impact of Gentamicin-Loaded Bone Graft on Defect Healing in a Sheep Model

Infections of bone are severe complications, and an optimization of grafting material with antimicrobial drugs might be useful for prevention and treatment. This study aimed to investigate the influence of gentamicin-loaded bone graft on the healing of bone defects in a sheep model. Metaphyseal and diaphyseal drill hole defects (diameter: 6 mm, depth: 15 mm) were filled with graft or gentamicin-loaded graft (50 mg/g graft) or were left untreated. Analysis of regeneration after three and nine weeks, micro-computed tomography (μCT), and histology revealed a significant increase in bone formation in the drill hole defects, which began at the edges of the holes and grew over time into the defect center. The amount of graft decreased over time due to active resorption by osteoclasts, while osteoblasts formed new bone. No difference between the groups was seen after three weeks. After nine weeks, significantly less mineralized tissue was formed in the gentamicin-loaded graft group. Signs of inflammatory reactions were seen in all three groups. Even though the applied gentamicin concentration was based on the concentration of gentamicin mixed with cement, the healing process was impaired. When using local gentamicin, a dose-dependent, compromising effect on bone healing should be considered.

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Feasibility of Application of the Newly Developed Nano-Biomaterial, β-TCP/PDLLA, in Maxillofacial Reconstructive Surgery: A Pilot Rat Study

Nanomaterials ◽

10.3390/nano11020303 ◽

2021 ◽

Vol 11 (2) ◽

pp. 303

Author(s):

Erina Toda ◽

Yunpeng Bai ◽

Jingjing Sha ◽

Quang Ngoc Dong ◽

Huy Xuan Ngo ◽

...

Keyword(s):

Bone Graft ◽

Reconstructive Surgery ◽

Leptin Receptor ◽

Early Stage ◽

Healing Process ◽

Bone Defects ◽

Micro Ct ◽

Sprague Dawley ◽

Micro Computed Tomography ◽

Mineral Density

This study was performed to examine the applicability of the newly developed nano-biocomposite, β-tricalcium phosphate (β-TCP)/u-HA/poly-d/l-lactide (PDLLA), to bone defects in the oral and maxillofacial area. This novel nano-biocomposite showed several advantages, including biocompatibility, biodegradability, and osteoconductivity. In addition, its optimal plasticity also allowed its utilization in irregular critical bone defect reconstructive surgery. Here, three different nano-biomaterials, i.e., β-TCP/PDLLA, β-TCP, and PDLLA, were implanted into critical bone defects in the right lateral mandible of 10-week-old Sprague–Dawley (SD) rats as bone graft substitutes. Micro-computed tomography (Micro-CT) and immunohistochemical staining for the osteogenesis biomarkers, Runx2, osteocalcin, and the leptin receptor, were performed to investigate and compare bone regeneration between the groups. Although the micro-CT results showed the highest bone mineral density (BMD) and bone volume to total volume (BV/TV) with β-TCP, immunohistochemical analysis indicated better osteogenesis-promoting ability of β-TCP/PDLLA, especially at an early stage of the bone healing process. These results confirmed that the novel nano-biocomposite, β-TCP/PDLLA, which has excellent biocompatibility, bioresorbability and bioactive/osteoconductivity, has the potential to become a next-generation biomaterial for use as a bone graft substitute in maxillofacial reconstructive surgery.

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Longitudinal Imaging of Liver Cancer Using MicroCT and Nanoparticle Contrast Agents in CRISPR/Cas9-Induced Liver Cancer Mouse Model

Technology in Cancer Research & Treatment ◽

10.1177/15330338211016466 ◽

2021 ◽

Vol 20 ◽

pp. 153303382110164

Author(s):

Sang Bu An ◽

Kwangmo Yang ◽

Chang Won Kim ◽

Si Ho Choi ◽

Eunji Kim ◽

...

Keyword(s):

Computed Tomography ◽

Liver Cancer ◽

Contrast Agents ◽

Kupffer Cells ◽

Micro Computed Tomography ◽

Hepatic Parenchyma ◽

Heterogeneous Distribution ◽

Computed Tomography Images ◽

Longitudinal Imaging ◽

Over Time

Introduction: Micro-computed tomography with nanoparticle contrast agents may be a suitable tool for monitoring the time course of the development and progression of tumors. Here, we suggest a practical and convenient experimental method for generating and longitudinally imaging murine liver cancer models. Methods: Liver cancer was induced in 6 experimental mice by injecting clustered regularly interspaced short palindromic repeats/clustered regularly interspaced short palindromic repeats-associated protein 9 plasmids causing mutations in genes expressed by hepatocytes. Nanoparticle agents are captured by Kupffer cells and detected by micro-computed tomography, thereby enabling longitudinal imaging. A total of 9 mice were used for the experiment. Six mice were injected with both plasmids and contrast, 2 injected with contrast alone, and one not injected with either agent. Micro-computed tomography images were acquired every 2- up to 14-weeks after cancer induction. Results: Liver cancer was first detected by micro-computed tomography at 8 weeks. The mean value of hepatic parenchymal attenuation remained almost unchanged over time, although the standard deviation of attenuation, reflecting heterogeneous contrast enhancement of the hepatic parenchyma, increased slowly over time in all mice. Histopathologically, heterogeneous distribution and aggregation of Kupffer cells was more prominent in the experimental group than in the control group. Heterogeneous enhancement of hepatic parenchyma, which could cause image quality deterioration and image misinterpretation, was observed and could be due to variation in Kupffer cells distribution. Conclusion: Micro-computed tomography with nanoparticle contrast is useful in evaluating the induction and characteristics of liver cancer, determining appropriate size of liver cancer for testing, and confirming therapeutic response.

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Dietary Melatonin and Glycine Decrease Tumor Growth through Antiangiogenic Activity in Experimental Colorectal Liver Metastasis

Nutrients ◽

10.3390/nu13062035 ◽

2021 ◽

Vol 13 (6) ◽

pp. 2035

Author(s):

Mindaugas Kvietkauskas ◽

Viktorija Zitkute ◽

Bettina Leber ◽

Kestutis Strupas ◽

Philipp Stiegler ◽

...

Keyword(s):

Side Effects ◽

Liver Metastasis ◽

Tumor Volume ◽

Treatment Strategies ◽

Blood Parameters ◽

Proliferation Index ◽

Micro Computed Tomography ◽

Cancer Proliferation ◽

Inhibitory Function ◽

Over Time

Despite multimodal treatment strategies, clinical outcomes of advanced stage colorectal cancer (CRC) patients remain poor. Neoadjuvant/adjuvant chemotherapy efficacy is limited due to chemoresistance, toxicity, and negative side effects. Since both melatonin and glycine have anti-cancer activities without relevant side effects, this study was designed to investigate their combined effects in experimental CRC liver metastases. CRC metastasis with CC531 cells were induced in male Wistar rats. Melatonin and glycine alone or their combination were supplemented for 14 days (n = 100). Blood parameters, a micro-computed tomography scan (tumor volume over time), and immunohistochemistry for Ki67 and CD31 expression in tumor tissue were compared between groups. Melatonin and glycine alone significantly reduced the tumor volume by 63.2% (p = 0.002) and 43% (p = 0.044) over time, respectively, while tumor volume increased by 8.7% in the controls. Moreover, treatment with melatonin and glycine alone reduced the tumor proliferation index. Most interestingly, the combination therapy did not have any influence on the above-mentioned tumor parameters. The leukocyte count was significantly increased with melatonin at the end of the experiment (p = 0.012) which was due to a high lymphocytes count. Tumor microvascular density was significantly reduced in all treatment groups. The results of this study suggest an inhibitory function for melatonin and glycine alone in the case of CRC liver metastasis growth by acting as natural antiangiogenic molecules, followed by angiogenesis-dependent cancer proliferation and immunomodulation.

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Use of Carboxymethyl Cellulose and Collagen Carrier with Equine Bone Lyophilisate Suggests Late Onset Bone Regenerative Effect in a Humerus Drill Defect – A Pilot Study in Six Sheep

The Open Orthopaedics Journal ◽

10.2174/1874325001004010181 ◽

2010 ◽

Vol 4 (1) ◽

pp. 181-187 ◽

Cited By ~ 3

Author(s):

Jonas Jensen ◽

Casper Bindzus Foldager ◽

Thomas Vestergaard Jakobsen ◽

Kjeld Søballe ◽

Cody Bünger ◽

...

Keyword(s):

Computed Tomography ◽

Carboxymethyl Cellulose ◽

Late Onset ◽

Demineralized Bone Matrix ◽

Bone Matrix ◽

Quantitative Computed Tomography ◽

Drill Hole ◽

Micro Computed Tomography ◽

Mineral Density ◽

Total Bone Mineral Density

We assessed the use of a filler compound together with the osteoinductive demineralized bone matrix (DBM), Colloss E. The filler was comprised of carboxymethyl-cellulose and collagen type 1. The purpose of the study was to see if the filler compound would enhance the bone formation and distribute the osteoinductive stimulus throughout the bone defect. Six sheep underwent a bilateral humerus drill defect. The drill hole was filled with a compound consisting of 100 mg CMC, 100 mg collagen powder, and 1 ccm autologous full blood in one side, and a combination of this filler compound and 20 mg Colloss E in the other. The animals were divided into three groups of two animals and observed for 8, 12 and 16 weeks. Drill holes was evaluated using quantitative computed tomography (QCT), micro computed tomography (µCT) and histomorphometry. Mean total bone mineral density (BMD) of each implantation site was calculated with both QCT and µCT. Bone volume to total volume (BV/TV) was analyzed using µCT and histomorphometry. Although not statistically significant, results showed increased bone BMD after 16 weeks in µCT data and an increased BV/TV after 16 weeks in both µCT and histology. Correlation between QCT and µCT was R2 = 0.804. Correlation between histomorphometry and µCT BV/TV data was R2 = 0.8935 and with an average overrepresentation of 8.2% in histomorphometry. In conclusion the CMC-Collagen + Colloss E filler seems like a viable osteogenic bone filler mid- to long term. A correlation was found between the analytical methods used in this study.

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Vascular endothelial growth factor is expressed along with its receptors during the healing process of bone and bone marrow after drill-hole injury in rats

Bone ◽

10.1016/s8756-3282(03)00053-x ◽

2003 ◽

Vol 32 (5) ◽

pp. 491-501 ◽

Cited By ~ 104

Author(s):

Soshi Uchida ◽

Akinori Sakai ◽

Hideaki Kudo ◽

Hajime Otomo ◽

Makoto Watanuki ◽

...

Keyword(s):

Bone Marrow ◽

Vascular Endothelial Growth Factor ◽

Growth Factor ◽

Healing Process ◽

Drill Hole ◽

Vascular Endothelial ◽

Endothelial Growth Factor

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Abstract 452: Longitudinal Visualization of Calcification Genesis and Growth in vivo : Novel Implications for Plaque Vulnerability

Arteriosclerosis Thrombosis and Vascular Biology ◽

10.1161/atvb.36.suppl_1.452 ◽

2016 ◽

Vol 36 (suppl_1) ◽

Author(s):

Joshua D Hutcheson ◽

Claudia Goettsch ◽

Brett Pieper ◽

Tan Pham ◽

Jung Choi ◽

...

Keyword(s):

Cardiovascular Risk ◽

Aortic Root ◽

Atherogenic Diet ◽

Alizarin Red S ◽

Arterial Calcification ◽

Micro Computed Tomography ◽

Alizarin Red ◽

Histological Sections ◽

Over Time

Background: Clinical evidence links arterial calcification and cardiovascular risk. Fibrous cap microcalcifications can promote atherosclerotic plaque failure, and large calcifications can stabilize the plaque. Therefore, calcification morphology can determine cardiovascular morbidity, but temporal patterns of calcific mineral deposition and growth remain unknown. Results: Apolipoprotein E-deficient ( Apoe-/- ) mice on an atherogenic diet develop plaque calcification. Longitudinal studies were performed using two different fluorescent calcium tracers injected intravenously into Apoe-/- mice: calcein injection following 18 weeks of atherogenic diet (n=7) and alizarin red S injection into the same mice 1 (n=4) or 3 (n=3) weeks later. Imaging green (calcein) and red (alizarin red S) fluorescence provided snapshots of aortic calcification at 18, 19, and 21 weeks. Observations within histological sections revealed green microcalcifications at 18 weeks embedded within alizarin red stained larger calcifications that were formed by 19 weeks (a). These data demonstrate that microcalcifications present at the start of calcification become the core of the larger calcifications that develop over time. Serial histological sections from aortic root to arch (b) were digitally reconstructed into 3D volumes (c) to reveal total calcific burden and localization within the aortic wall (d). Total calcification volume increased at a significant rate of 6.0x10 6 μm 3 per week (R 2 =0.99, p=0.007) and progressed from aortic arch to aortic root over time (p<0.001). Observations closely match calcification morphologies found by micro-computed tomography of human coronary arteries. Conclusion: Temporal and spatial understanding arterial calcification growth is crucial given the link between mineral morphology and cardiovascular risk, and these techniques provide a method for testing therapeutic approaches to control calcification morphology over time in situ .

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Analysis of microscopic bone properties in an osteoporotic sheep model: a combined biomechanics, FE and ToF-SIMS study

Journal of The Royal Society Interface ◽

10.1098/rsif.2018.0793 ◽

2019 ◽

Vol 16 (151) ◽

pp. 20180793 ◽

Cited By ~ 3

Author(s):

R. Müller ◽

A. Henss ◽

M. Kampschulte ◽

M. Rohnke ◽

A. C. Langheinrich ◽

...

Keyword(s):

Biomechanical Testing ◽

Tissue Level ◽

Osteoporotic Bone ◽

Compression Tests ◽

Micro Computed Tomography ◽

Deficient Diet ◽

Element Analysis ◽

Sheep Model ◽

Tissue Properties ◽

Bone Properties

The present study deals with the characterization of bone quality in a sheep model of postmenopausal osteoporosis. Sheep were sham operated ( n = 7), ovariectomized ( n = 6), ovariectomized and treated with deficient diet ( n = 8) or ovariectomized, treated with deficient diet and glucocorticoid injections ( n = 7). The focus of the study is on the microscopic properties at tissue level. Microscopic mechanical properties of osteoporotic bone were evaluated by a combination of biomechanical testing and mathematical modelling. Sample stiffness and strength were determined by compression tests and finite-element analysis of stress states was conducted. From this, an averaged microscopic Young’s modulus at tissue level was determined. Trabecular structure as well as mineral and collagen distribution in samples of sheep vertebrae were analysed by micro-computed tomography and time-of-flight secondary ion mass spectrometry. In the osteoporotic sheep model, a disturbed fibril structure in the triple treated group was observed, but bone loss only occurred in form of reduced trabecular number and thickness and cortical decline, while quality of the residual bone was preserved. The preserved bone tissue properties in the osteoporotic sheep model allowed for an estimation of bone strength which behaves similar to the human case.

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Method for Assessment of Changes in the Width of Cracks in Cement Composites with Use of Computer Image Processing and Analysis

Studia Geotechnica et Mechanica ◽

10.1515/sgem-2017-0017 ◽

2017 ◽

Vol 39 (2) ◽

pp. 73-80 ◽

Cited By ~ 4

Author(s):

Kamil Tomczak ◽

Jacek Jakubowski ◽

Przemysław Fiołek

Keyword(s):

Image Processing ◽

Crack Width ◽

Healing Process ◽

Cement Composites ◽

Self Healing ◽

Initial Image ◽

Scale Invariant ◽

Line Segments ◽

Changes Over Time ◽

Over Time

Abstract Crack width measurement is an important element of research on the progress of self-healing cement composites. Due to the nature of this research, the method of measuring the width of cracks and their changes over time must meet specific requirements. The article presents a novel method of measuring crack width based on images from a scanner with an optical resolution of 6400 dpi, subject to initial image processing in the ImageJ development environment and further processing and analysis of results. After registering a series of images of the cracks at different times using SIFT conversion (Scale-Invariant Feature Transform), a dense network of line segments is created in all images, intersecting the cracks perpendicular to the local axes. Along these line segments, brightness profiles are extracted, which are the basis for determination of crack width. The distribution and rotation of the line of intersection in a regular layout, automation of transformations, management of images and profiles of brightness, and data analysis to determine the width of cracks and their changes over time are made automatically by own code in the ImageJ and VBA environment. The article describes the method, tests on its properties, sources of measurement uncertainty. It also presents an example of application of the method in research on autogenous self-healing of concrete, specifically the ability to reduce a sample crack width and its full closure within 28 days of the self-healing process.

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Endogenous Production of n-3 Polyunsaturated Fatty Acids Promotes Fracture Healing in Mice

Journal of Healthcare Engineering ◽

10.1155/2017/3571267 ◽

2017 ◽

Vol 2017 ◽

pp. 1-6 ◽

Cited By ~ 1

Author(s):

Yuhui Chen ◽

He Cao ◽

Dawei Sun ◽

Changxin Lin ◽

Liang Wang ◽

...

Keyword(s):

Transgenic Mice ◽

Fracture Healing ◽

Histological Analysis ◽

Callus Formation ◽

Healing Process ◽

Proximal Femoral Fracture ◽

Fracture Repair ◽

Micro Ct ◽

Micro Computed Tomography ◽

X Ray

Bone fracture is a global healthcare issue for high rates of delayed healing and nonunions. Although n-3 polyunsaturated fatty acid (PUFA) is considered as a beneficial factor for bone metabolism, only few studies till date focused on the effects of n-3 PUFAs on fracture healing. In this study, we investigated the effect of endogenous n-3 PUFAs on fracture healing by measuring femur fracture repair in bothfat-1transgenic mice and WT mice. Proximal femoral fracture model was established infat-1transgenic mice and WT mice, respectively, and then the fracture was analyzed by using X-ray, micro-computed tomography (micro-CT), and histological assessment at 7, 14, 21, 28, and 35 days after fixation. The results showed that compared with WT mice,fat-1mice exhibited acceleration in fracture healing through radiographic and histological analysis (18–21 days versus 21–28 days postfracture). Meanwhile, X-ray and micro-CT analysis that showed better remodeling callus formation were in thefat-1group compared to WT group. Furthermore, histological analysis revealed that endogenous n-3 PUFAs promoted local endochondral ossification and accelerated the remodeling of calcified calluses after fracture. In conclusion, the present study indicated that endogenously produced n-3 PUFAs promote fracture healing process and accelerate bone remodeling in mice, and supplementation of n-3 PUFAs was positively associated with fracture healing.

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