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3 results on '"Luc Nimeskern"'

1. Magnetic resonance imaging of the ear for patient-specific reconstructive surgery.

Author

Luc Nimeskern, Eva-Maria Feldmann, Willy Kuo, Silke Schwarz, Eva Goldberg-Bockhorn, Susanne Dürr, Ralph Müller, Nicole Rotter, and Kathryn S Stok

Subjects
Medicine, Science
Abstract

INTRODUCTION: Like a fingerprint, ear shape is a unique personal feature that should be reconstructed with a high fidelity during reconstructive surgery. Ear cartilage tissue engineering (TE) advantageously offers the possibility to use novel 3D manufacturing techniques to reconstruct the ear, thus allowing for a detailed auricular shape. However it also requires detailed patient-specific images of the 3D cartilage structures of the patient's intact contralateral ear (if available). Therefore the aim of this study was to develop and evaluate an imaging strategy for acquiring patient-specific ear cartilage shape, with sufficient precision and accuracy for use in a clinical setting. METHODS AND MATERIALS: Magnetic resonance imaging (MRI) was performed on 14 volunteer and six cadaveric auricles and manually segmented. Reproducibility of cartilage volume (Cg.V), surface (Cg.S) and thickness (Cg.Th) was assessed, to determine whether raters could repeatedly define the same volume of interest. Additionally, six cadaveric auricles were harvested, scanned and segmented using the same procedure, then dissected and scanned using high resolution micro-CT. Correlation between MR and micro-CT measurements was assessed to determine accuracy. RESULTS: Good inter- and intra-rater reproducibility was observed (precision errors 0.82), but low for Cg.Th (0.95) demonstrated high accuracy. DISCUSSION AND CONCLUSION: This study demonstrated that precision and accuracy of the proposed method was high enough to detect patient-specific variation in ear cartilage geometry. The present study provides a clinical strategy to access the necessary information required for the production of 3D ear scaffolds for TE purposes, including detailed patient-specific shape. Furthermore, the protocol is applicable in daily clinical practice with existing infrastructure.

Published
2014
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2. Trophic effects of adipose-tissue-derived and bone-marrow-derived mesenchymal stem cells enhance cartilage generation by chondrocytes in co-culture

Author

J.L.M. Koevoet, Kathryn S. Stok, Marcel Karperien, Mieke M. Pleumeekers, Luc Nimeskern, G.J.V.M. van Osch, Otorhinolaryngology and Head and Neck Surgery, Plastic and Reconstructive Surgery and Hand Surgery, Orthopedics and Sports Medicine, and Developmental BioEngineering

Subjects
Cartilage, Articular, 0301 basic medicine, Physiology, Cell- and Tissue-Based Therapy, lcsh:Medicine, Gene Expression, Cell Communication, 02 engineering and technology, Biochemistry, Extracellular matrix, Mice, Endocrinology, Cell Signaling, Animal Cells, Medicine and Health Sciences, lcsh:Science, Cells, Cultured, Connective Tissue Cells, Multidisciplinary, Chemistry, Stem Cells, Cell Differentiation, Extracellular Matrix, Cell biology, medicine.anatomical_structure, Adipose Tissue, Connective Tissue, Paracrine Signaling, Female, Biological Cultures, Anatomy, Cellular Types, Chondrogenesis, Research Article, Signal Transduction, 0206 medical engineering, Mice, Nude, Bone Marrow Cells, Research and Analysis Methods, Chondrocyte, 03 medical and health sciences, Chondrocytes, Tissue Repair, medicine, Animals, Humans, Regeneration, Aggrecan, Endocrine Physiology, Regeneration (biology), Cartilage, lcsh:R, Mesenchymal stem cell, Biology and Life Sciences, Proteins, Mesenchymal Stem Cells, Cell Biology, Cell Cultures, 020601 biomedical engineering, Coculture Techniques, Biological Tissue, 030104 developmental biology, Cell culture, Culture Media, Conditioned, lcsh:Q, Cattle, Physiological Processes, Collagens, Developmental Biology
Abstract

Aims Combining mesenchymal stem cells (MSCs) and chondrocytes has great potential for cell-based cartilage repair. However, there is much debate regarding the mechanisms behind this concept. We aimed to clarify the mechanisms that lead to chondrogenesis (chondrocyte driven MSC-differentiation versus MSC driven chondroinduction) and whether their effect was dependent on MSC-origin. Therefore, chondrogenesis of human adipose-tissue-derived MSCs (hAMSCs) and bone-marrow-derived MSCs (hBMSCs) combined with bovine articular chondrocytes (bACs) was compared. Methods hAMSCs or hBMSCs were combined with bACs in alginate and cultured in vitro or implanted subcutaneously in mice. Cartilage formation was evaluated with biochemical, histological and biomechanical analyses. To further investigate the interactions between bACs and hMSCs, (1) co-culture, (2) pellet, (3) Transwell® and (4) conditioned media studies were conducted. Results The presence of hMSCs–either hAMSCs or hBMSCs—increased chondrogenesis in culture; deposition of GAG was most evidently enhanced in hBMSC/bACs. This effect was similar when hMSCs and bAC were combined in pellet culture, in alginate culture or when conditioned media of hMSCs were used on bAC. Species-specific gene-expression analyses demonstrated that aggrecan was expressed by bACs only, indicating a predominantly trophic role for hMSCs. Collagen-10-gene expression of bACs was not affected by hBMSCs, but slightly enhanced by hAMSCs. After in-vivo implantation, hAMSC/bACs and hBMSC/bACs had similar cartilage matrix production, both appeared stable and did not calcify. Conclusions This study demonstrates that replacing 80% of bACs by either hAMSCs or hBMSCs does not influence cartilage matrix production or stability. The remaining chondrocytes produce more matrix due to trophic factors produced by hMSCs., PLoS ONE, 13 (2), ISSN:1932-6203

Published
2018

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