In vivo micro-computed tomography allows direct three-dimensional quantification of both bone formation and bone resorption parameters using time-lapsed imaging

Matrix metalloproteinase (MMP)-2 and MMP-9 are well-known gelatinases that disrupt the extracellular matrix, including gelatin. However, the advantages of modulating MMP expression in gelatin-based materials for applications in bone regenerative medicine have not been fully clarified. In this study, we examined the effects of epigallocatechin gallate (EGCG), a major polyphenol catechin isolated from green tea, on MMP expression in gelatin sponges and its association with bone formation. Four gelatin sponges with or without EGCG were prepared and implanted into bone defects for up to 4 weeks. Histological and immunohistological staining were performed. Micro-computed tomography was used to estimate the bone-forming capacity of each sponge. Our results showed that EGCG integration attenuated MMP-2 (70.6%) and -9 expression (69.1%) in the 1 week group, increased residual gelatin (118.7%), and augmented bone formation (101.8%) in the 4 weeks group in critical-sized bone defects of rat calvaria compared with vacuum-heated gelatin sponges without EGCG. Moreover, vacuum-heated gelatin sponges with EGCG showed superior bone formation compared with other sponges. The results indicated that integration of EGCG in gelatin-based materials modulated the production and activity of MMP-2 and -9 in vivo, thereby enhancing bone-forming capacity.

Download Full-text

Evaluation of Three-dimensional Image Registration Methodologies for In Vivo Micro-computed Tomography

Annals of Biomedical Engineering ◽

10.1007/s10439-006-9168-7 ◽

2006 ◽

Vol 34 (10) ◽

pp. 1587-1599 ◽

Cited By ~ 45

Author(s):

Steven K. Boyd ◽

Stephan Moser ◽

Michael Kuhn ◽

Robert J. Klinck ◽

Peter L. Krauze ◽

...

Keyword(s):

Computed Tomography ◽

Image Registration ◽

Three Dimensional ◽

Micro Computed Tomography ◽

Dimensional Image

Download Full-text

Impaired bone formation in ovariectomized mice reduces implant integration as indicated by longitudinal in vivo micro-computed tomography

PLoS ONE ◽

10.1371/journal.pone.0184835 ◽

2017 ◽

Vol 12 (9) ◽

pp. e0184835 ◽

Cited By ~ 10

Author(s):

Zihui Li ◽

Gisela Kuhn ◽

Michael Schirmer ◽

Ralph Müller ◽

Davide Ruffoni

Keyword(s):

Computed Tomography ◽

Bone Formation ◽

Micro Computed Tomography ◽

Ovariectomized Mice ◽

Implant Integration

Download Full-text

Three-Dimensional In Vivo Imaging of the Murine Liver: A Micro-Computed Tomography-Based Anatomical Study

PLoS ONE ◽

10.1371/journal.pone.0031179 ◽

2012 ◽

Vol 7 (2) ◽

pp. e31179 ◽

Cited By ~ 29

Author(s):

Teresa Fiebig ◽

Hanne Boll ◽

Giovanna Figueiredo ◽

Hans Ulrich Kerl ◽

Stefanie Nittka ◽

...

Keyword(s):

Computed Tomography ◽

In Vivo Imaging ◽

Three Dimensional ◽

Anatomical Study ◽

Micro Computed Tomography ◽

Murine Liver

Download Full-text

In-Vivo Degradation Behavior and Osseointegration of 3D Powder-Printed Calcium Magnesium Phosphate Cement Scaffolds

Materials ◽

10.3390/ma14040946 ◽

2021 ◽

Vol 14 (4) ◽

pp. 946

Author(s):

Katharina Kowalewicz ◽

Elke Vorndran ◽

Franziska Feichtner ◽

Anja-Christina Waselau ◽

Manuel Brueckner ◽

...

Keyword(s):

Three Dimensional ◽

Bone Substitutes ◽

Magnesium Phosphate ◽

Degradation Behavior ◽

Micro Computed Tomography ◽

Calcium Magnesium ◽

Interest In Research ◽

In Vivo Degradation ◽

Volume Decrease

Calcium magnesium phosphate cements (CMPCs) are promising bone substitutes and experience great interest in research. Therefore, in-vivo degradation behavior, osseointegration and biocompatibility of three-dimensional (3D) powder-printed CMPC scaffolds were investigated in the present study. The materials Mg225 (Ca0.75Mg2.25(PO4)2) and Mg225d (Mg225 treated with diammonium hydrogen phosphate (DAHP)) were implanted as cylindrical scaffolds (h = 5 mm, Ø = 3.8 mm) in both lateral femoral condyles in rabbits and compared with tricalcium phosphate (TCP). Treatment with DAHP results in the precipitation of struvite, thus reducing pore size and overall porosity and increasing pressure stability. Over 6 weeks, the scaffolds were evaluated clinically, radiologically, with Micro-Computed Tomography (µCT) and histological examinations. All scaffolds showed excellent biocompatibility. X-ray and in-vivo µCT examinations showed a volume decrease and increasing osseointegration over time. Structure loss and volume decrease were most evident in Mg225. Histologically, all scaffolds degraded centripetally and were completely traversed by new bone, in which the remaining scaffold material was embedded. While after 6 weeks, Mg225d and TCP were still visible as a network, only individual particles of Mg225 were present. Based on these results, Mg225 and Mg225d appear to be promising bone substitutes for various loading situations that should be investigated further.

Download Full-text

Heidelberg-mCT-Analyzer: a novel method for standardized microcomputed-tomography-guided evaluation of scaffold properties in bone and tissue research

Royal Society Open Science ◽

10.1098/rsos.150496 ◽

2015 ◽

Vol 2 (11) ◽

pp. 150496 ◽

Cited By ~ 10

Author(s):

Fabian Westhauser ◽

Christian Weis ◽

Melanie Hoellig ◽

Tyler Swing ◽

Gerhard Schmidmaier ◽

...

Keyword(s):

Tissue Engineering ◽

Bone Tissue Engineering ◽

Bone Tissue ◽

Three Dimensional ◽

Characteristic Parameter ◽

Micro Computed Tomography ◽

Mineral Density ◽

Independent Analysis ◽

Scaffold Properties

Bone tissue engineering and bone scaffold development represent two challenging fields in orthopaedic research. Micro-computed tomography (mCT) allows non-invasive measurement of these scaffolds’ properties in vivo . However, the lack of standardized mCT analysis protocols and, therefore, the protocols’ user-dependency make interpretation of the reported results difficult. To overcome these issues in scaffold research, we introduce the Heidelberg-mCT-Analyzer. For evaluation of our technique, we built 10 bone-inducing scaffolds, which underwent mCT acquisition before ectopic implantation (T0) in mice, and at explantation eight weeks thereafter (T1). The scaffolds’ three-dimensional reconstructions were automatically segmented using fuzzy clustering with fully automatic level-setting. The scaffold itself and its pores were then evaluated for T0 and T1. Analysing the scaffolds’ characteristic parameter set with our quantification method showed bone formation over time. We were able to demonstrate that our algorithm obtained the same results for basic scaffold parameters (e.g. scaffold volume, pore number and pore volume) as other established analysis methods. Furthermore, our algorithm was able to analyse more complex parameters, such as pore size range, tissue mineral density and scaffold surface. Our imaging and post-processing strategy enables standardized and user-independent analysis of scaffold properties, and therefore is able to improve the quantitative evaluations of scaffold-associated bone tissue-engineering projects.

Download Full-text

Longitudinal in vivo evaluation of bone regeneration by combined measurement of multi-pinhole SPECT and micro-CT for tissue engineering

Scientific Reports ◽

10.1038/srep10238 ◽

2015 ◽

Vol 5 (1) ◽

Cited By ~ 16

Author(s):

Philipp S. Lienemann ◽

Stéphanie Metzger ◽

Anna-Sofia Kiveliö ◽

Alain Blanc ◽

Panagiota Papageorgiou ◽

...

Keyword(s):

Computed Tomography ◽

High Resolution ◽

Bone Formation ◽

Bone Regeneration ◽

Bone Defects ◽

Histological Evaluation ◽

Biological Processes ◽

Micro Ct ◽

Pinhole Spect

Abstract Over the last decades, great strides were made in the development of novel implants for the treatment of bone defects. The increasing versatility and complexity of these implant designs request for concurrent advances in means to assess in vivo the course of induced bone formation in preclinical models. Since its discovery, micro-computed tomography (micro-CT) has excelled as powerful high-resolution technique for non-invasive assessment of newly formed bone tissue. However, micro-CT fails to provide spatiotemporal information on biological processes ongoing during bone regeneration. Conversely, due to the versatile applicability and cost-effectiveness, single photon emission computed tomography (SPECT) would be an ideal technique for assessing such biological processes with high sensitivity and for nuclear imaging comparably high resolution (<1 mm). Herein, we employ modular designed poly(ethylene glycol)-based hydrogels that release bone morphogenetic protein to guide the healing of critical sized calvarial bone defects. By combined in vivo longitudinal multi-pinhole SPECT and micro-CT evaluations we determine the spatiotemporal course of bone formation and remodeling within this synthetic hydrogel implant. End point evaluations by high resolution micro-CT and histological evaluation confirm the value of this approach to follow and optimize bone-inducing biomaterials.

Download Full-text

Micro-Computed Tomography-Based Three-Dimensional Anatomical Structure of the Region Around the Pterygoid Hamulus

The Cleft Palate-Craniofacial Journal ◽

10.1177/10556656211036302 ◽

2021 ◽

pp. 105566562110363

Author(s):

Jiuli Zhao ◽

Hengyuan Ma ◽

Yongqian Wang ◽

Tao Song ◽

Chanyuan Jiang ◽

...

Keyword(s):

Computed Tomography ◽

Treatment Options ◽

Muscle Fibers ◽

Three Dimensional ◽

Anatomical Structure ◽

Micro Computed Tomography ◽

3 Dimensional ◽

Middle Ear Ventilation ◽

Optimal Approach ◽

Velopharyngeal Function

Objective Palatoplasty would involve the structures around the pterygoid hamulus. However, clinicians hold different opinions on the optimal approach for the muscles and palatine aponeurosis around the pterygoid hamulus. The absence of a consensus regarding this point can be attributed to the lack of investigations on the exact anatomy of this region. Therefore, we used micro-computed tomography to examine the anatomical structure of the region surrounding the pterygoid hamulus. Design Cadaveric specimens were stained with iodine–potassium iodide and scanned by micro-computed tomography to study the structures of the tissues, particularly the muscle fibers. We imported Digital Imaging and Communications in Medicine images to Mimics to reconstruct a 3-dimensional model and simplified the model. Results Three muscles were present around the pterygoid hamulus, namely the palatopharyngeus (PP), superior constrictor (SC), and tensor veli palatini (TVP). The hamulus connects these muscles as a key pivot. The TVP extended to the palatine aponeurosis, which bypassed the pterygoid hamulus, and linked the PP and SC. Some muscle fibers of the SC originated from the hamulus, the aponeurosis of which was wrapped around the hamulus. There was a distinct gap between the pterygoid hamulus and the palatine aponeurosis. This formed a pulley-like structure around the pterygoid hamulus. Conclusions Transection or fracture of the palatine aponeurosis or pterygoid hamulus, respectively, may have detrimental effects on the muscles around the pterygoid hamulus, which play essential roles in the velopharyngeal function and middle ear ventilation. Currently, cleft palate repair has limited treatment options with proven successful outcomes.

Download Full-text