scholarly journals Numerical modelling of the ultrasound effect on bone fracture healing

2016 ◽  
Author(s):  
Κωνσταντίνος Γρίβας
Keyword(s):  
Numerical Modelling ◽  
Fracture Healing ◽  
Bone Fracture ◽  
Bone Fracture Healing ◽  
Ultrasound Effect

Η πώρωση οστικών καταγμάτων είναι μια εξαιρετικά σύνθετη διεργασία κατά τη διάρκεια της οποίας ποικίλοι κυτταρικοί και μοριακοί μηχανισμοί λαμβάνουν χώρα. Σκοπό της διδακτορικής διατριβής αποτέλεσε η δημιουργία ενός νέου πρότυπου υπολογιστικού εργαλείου το οποίο θα προσομοιώνει τη διαφοροποίηση των ιστών μετά από κάταγμα και θα διερευνεί την επίδραση των χαμηλής έντασης υπερήχων στη διαδικασία πώρωσης οστικών καταγμάτων, παρέχοντας εις βάθος καινούργια γνώση αναφορικά με τους ακριβείς μηχανισμούς που οδηγούν στην επιτάχυνση της ανάπλασης των καταγματικών οστών. Η παρούσα διδακτορική διατριβή υλοποιήθηκε σε τρεις φάσεις. Κατά τη διάρκεια της πρώτης φάσης αναπτύχθηκε μια νέα και απλή Μέθοδος Τοπικών Ολοκληρωτικών Εξισώσεων χωρίς Διακριτοποίηση (ΜΤΟχΔ) για την επίλυση του γραμμικού και μη-γραμμικού προβλήματος του πολλαπλασιασμού των μεσεγχυματικών κυττάρων με στόχο τη διερεύνηση της πιο αντιπροσωπευτικής από τις δύο περίπτωσης. Ακολούθως κατά τη διάρκεια της δεύτερης φάσης εργασιών υλοποιήθηκε ένα υβριδικό βιολογικό μαθηματικό μοντέλο βασισμένο σε αυτό της Peiffer et al. (2011). Το μοντέλο αυτό αποτελείται από α) ένα σύστημα Μερικών Διαφορικών Εξισώσεων (ΜΔΕ) που περιγράφει τη χωροχρονική εξέλιξη κυττάρων, αυξητικών παραγόντων, ιστών και της ακουστικής πίεσης του υπερήχου και β) ένα σύστημα εξισώσεων ταχύτητας για τα ενδοθηλιακά κύτταρα που ακτινογραφεί την ανάπτυξη του δικτύου των αιμοφόρων αγγείων. Η επίδραση των υπερήχων στο πολυεπίπεδο βιολογικό μοντέλο ελήφθη υπ’ όψιν με τέτοιο τρόπο ώστε πρωτίστως να επηρεάζει τη μεταφορά του Αγγειακού Ενδοθηλιακού Αυξητικού Παράγοντα (ΑΕΑΠ) σύμφωνα με προηγούμενες in vitro μελέτες. Τέλος, η τρίτη φάση της διδακτορικής διατριβής αφορά την παρουσίαση ενός μικρομηχανοβιολογικού μοντέλου βασισμένου στην μελέτη των Lacroix και Prendergast (2002) και εμπλουτισμένου με τους όρους που εισάγουν την επίδραση του υπερήχου στην πώρωση του οστού. Σε αυτή την κατεύθυνση συμπεριλαμβάνεται μια επαναληπτική διαδικασία η οποία συνδυάζει ένα μηχανικό μοντέλο που επιλύει το ποροελαστικό πρόβλημα και λαμβάνει υπ’ όψιν την επίδραση του μηχανικού φορτίου στον χρόνο, ένα βιολογικό μοντέλο διάχυσης για τον πολλαπλασιασμό των μεσεγχυματικών κυττάρων και το υβριδικό βιολογικό μοντέλο που αναπτύχθηκε κατά τη διάρκεια της δεύτερης φάσης. Οι καινοτόμες πτυχές της διδακτορικής διατριβής είναι α) η ανάπτυξη ενός νέου αριθμητικού μοντέλου το οποίο για πρώτη φορά προσομοιώνει τη διαδικασία της οστεοποίησης υπό την επίδραση των υπερήχων και β) η ανάπτυξη μια νέας και απλής ΜΤΟχΔ για την προσομοίωση του πολλαπλασιασμού των μεσεγχυματικών κυττάρων. Για το λόγο αυτό μπορεί να θεωρηθεί ως ένα βήμα προς την αξιολόγηση του υπερήχου στην διαδικασία πώρωσης καταγματικών οστών. Η εκτέλεση πειραματικών εφαρμογών υπερήχου σε συνδυασμό με την ανάπτυξη ενός πιο ολοκληρωμένου θεωρητικού πλαισίου μπορεί να βοηθήσει στην περαιτέρω κατανόηση του φαινομένου

scholarly journals Pericytes as a Source of Osteogenic Cells in Bone Fracture Healing

2019 ◽  
Vol 20 (5) ◽  
pp. 1079 ◽  
Author(s):  
Sopak Supakul ◽  
Kenta Yao ◽  
Hiroki Ochi ◽  
Tomohito Shimada ◽  
Kyoko Hashimoto ◽  
...  
Keyword(s):  
Fracture Healing ◽  
Bone Fracture ◽  
Bone Fractures ◽  
Callus Formation ◽  
Bone Diseases ◽  
Lineage Tracing ◽  
Osteogenic Potential ◽  
Bone Fracture Healing ◽  
Osteogenic Cells

Pericytes are mesenchymal cells that surround the endothelial cells of small vessels in various organs. These cells express several markers, such as NG2, CD146, and PDGFRβ, and play an important role in the stabilization and maturation of blood vessels. It was also recently revealed that like mesenchymal stem cells (MSCs), pericytes possess multilineage differentiation capacity, especially myogenic, adipogenic, and fibrogenic differentiation capacities. Although some previous studies have reported that pericytes also have osteogenic potential, the osteogenesis of pericytes can still be further elucidated. In the present study, we established novel methods for isolating and culturing primary murine pericytes. An immortalized pericyte line was also established. Multilineage induction of the pericyte line induced osteogenesis, adipogenesis, and chondrogenesis of the cells in vitro. In addition, pericytes that were injected into the fracture site of a bone fracture mouse model contributed to callus formation. Furthermore, in vivo pericyte-lineage-tracing studies demonstrated that endogenous pericytes also differentiate into osteoblasts and osteocytes and contribute to bone fracture healing as a cellular source of osteogenic cells. Pericytes can be a promising therapeutic candidate for treating bone fractures with a delayed union or nonunion as well as bone diseases causing bone defects.

scholarly journals Knockdown of SERPINB2 enhances the osteogenic differentiation of human bone marrow mesenchymal stem cells via activation of the Wnt/β-catenin signalling pathway

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Kai Hang ◽  
Li Ying ◽  
Jinwu Bai ◽  
Yibo Wang ◽  
Zhihui Kuang ◽  
...  
Keyword(s):  
Fracture Healing ◽  
Osteogenic Differentiation ◽  
Bone Fracture ◽  
Osteoblast Differentiation ◽  
Tibial Fracture ◽  
Bone Fractures ◽  
Bone Fracture Healing ◽  
Non Union

Abstract Background Globally, bone fractures are the most common musculoskeletal trauma, and approximately 8–10% of cases that fall into the categories of delayed or non-union healing. To date, there are no efficient pharmacological agents to accelerate the healing of bone fractures. Thus, it is necessary to find new strategies that accelerate bone healing and reduce the incidence of non-union or delayed fracture healing. Previous studies have revealed that the plasminogen activation system has been demonstrated to play an important role in bone metabolism. However, the function of SERPINB2 in the osteogenesis of hBMSCs remains unclear. Therefore, in this study, we investigated the effects and mechanism of SERPINB2 on osteogenic differentiation. Methods We investigated the osteogenesis effects of hBMSCs by both exogenous SerpinB2 protein and SERPINB2 gene silencing in vitro. Cell proliferation assay was used to assess the effect of exogenous SerpinB2 or SERPINB2 silencing on proliferation of hBMSCs. qPCR and Western blotting analysis detected the expression of target genes and proteins respectively. ALP staining was used to evaluated ALP activity and Alizarin Red staining (ARS) was used to evaluate mineral deposition. In vivo, a murie tibial fracture model was established, histological evaluation and radiographic analysis was used to confirm the therapeutic effects of SERPINB2 silencing in fracture healing. Statistical significance between two groups was determined by Student’s t test, one-way ANOVA or Bonferroni’s post-hoc test according to the distribution of the tested population. Results The addition of exogenous SerpinB2 protein inhibted osteoblast differentiation of hBMSCs in vitro, while SERPINB2 gene silencing significant promote osteoblast differentiation of hBMSCs in vitro. And silenced SERPINB2 gene also increased mineral deposits. Moreover, β-catenin levels were up-regulated by SERPINB2 gene depletion. And the enhancement of osteogenic differentiation induced by SERPINB2 silencing was almost inhibited by specific Wnt/β-catenin signaling pathway inhibitor. In a murine tibial fracture model, local injection of SERPINB2 siRNA improved bone fracture healing. Conclusions Taken together, these findings indicate that SERPINB2 silencing promoted osteogenic differentiation of BMSCs via the Wnt/β-catenin signaling pathway, and silenced SERPINB2 in vivo effectively promotes fracture healing, suggesting that SERPINB2 may be a novel target for bone fracture healing.

Using the Doppler Effect to Measure the Vibration of Human Bones: In Vitro Studies

1994 ◽  
Vol 208 (2) ◽  
pp. 127-129 ◽  
Author(s):  
T Flint ◽  
L Nokes ◽  
M Maheson ◽  
J P Woodcock
Keyword(s):  
Fracture Healing ◽  
Bone Fracture ◽  
Doppler Effect ◽  
Bone Fracture Healing ◽  
Human Bones ◽  
Experimental Apparatus ◽  
In Vitro Assessment ◽  
The Doppler Effect

A novel application of ultrasound Doppler theory to the measurement of bone vibration is described. The theory and experimental apparatus is outlined and its initial calibration and in vitro assessment reported. It is speculated that this method may be used clinically in order to monitor in vivo bone fracture healing.

scholarly journals Knockdown of SERPINB2 enhances the osteogenic differentiation of human bone marrow mesenchymal stem cells via activation of the Wnt/β-catenin signalling pathway

2021 ◽  
Author(s):  
Kai Hang ◽  
Li Ying ◽  
Jinwu Bai ◽  
Yibo Wang ◽  
Zhihui Kuang ◽  
...  
Keyword(s):  
Fracture Healing ◽  
Osteogenic Differentiation ◽  
Bone Fracture ◽  
Osteoblast Differentiation ◽  
Tibial Fracture ◽  
Bone Fractures ◽  
Bone Fracture Healing ◽  
Non Union

Abstract Background Globally, bone fractures are the most common musculoskeletal trauma, and approximately 8–10% of cases that fall into the categories of delayed or non-union healing. Treatment of impaired healing in these patients not only represents a tremendous burden on healthcare systems but also increases patients’ pain and financial burdens. To date, there are no efficient pharmacological agents to accelerate the healing of bone fractures. Thus, it is necessary to find new strategies that accelerate bone healing and reduce the incidence of non-union or delayed fracture healing. Previous studies have revealed that the plasminogen activation system has been demonstrated to play an important role in bone metabolism. However, the function of SERPINB2 in the osteogenesis of hBMSCs remains unclear. Therefore, in this study, we investigated the effects and mechanism of Apelin on osteogenic differentiation. Methods We investigated the osteogenesis effects of hBMSCs by both exogenous SERPINB2 protein and SERPINB2 silencing in vitro. Cell proliferation assay was used to assess the effect of exogenous SERPINB2 or SERPINB2 silencing on proliferation of hBMSCs. qPCR and Western blotting analysis detected the expression of target genes and proteins respectively. ALP staining was used to evaluated ALP activity and Alizarin Red staining (ARS) was used to evaluate mineral deposition. In vivo, a murie tibial fracture model was established, histological evaluation and radiographic analysis was used to confirm the therapeutic effects of SERPINB2 silencing in fracture healing. statistical significance between two groups was determined by Student’s t test, one-way ANOVA or Bonferroni’s post-hoc test according to the distribution of the tested population.Results The addition of exogenous SERPINB2 protein inhibted osteoblast differentiation of hBMSCs in vitro, while SERPINB2 gene silencing significant promote osteoblast differentiation of hBMSCs in vitro. And silence SERPINB2 gene also increased mineral deposits. Moreover, β-catenin levels were up-regulated by SERPINB2 gene depletion. And the enhancement of osteogenic differentiation induced by SERPINB2 silencing was almost inhibited by specific Wnt/β-catenin signaling pathway inhibitors. In a murine tibial fracture model, local injection of SERPINB2 siRNA improved bone fracture healing. Conclusions Taken together, these findings indicate that SERPINB2 silencing promoted osteogenic differentiation of BMSCs via the Wnt/β-catenin signaling pathway, and silenced SERPINB2 in vivo effectively promotes fracture healing, suggesting that SERPINB2 may be a novel target for bone fracture healing.

Ultrasonic Diagnosis for Bone Fracture Healing Process

2020 ◽  
Author(s):  
Satoshi Kimura ◽  
Keisuke Oe ◽  
Yohei Kumabe ◽  
Tomoaki Fukui ◽  
Takahiro Niikura ◽  
...  
Keyword(s):  
Fracture Healing ◽  
Bone Fracture ◽  
Healing Process ◽  
Ultrasonic Diagnosis ◽  
Bone Fracture Healing

scholarly journals Diminished Callus Size and Cartilage Synthesis in α1β1 Integrin-Deficient Mice during Bone Fracture Healing

2002 ◽  
Vol 160 (5) ◽  
pp. 1779-1785 ◽  
Author(s):  
Erika Ekholm ◽  
Kurt D. Hankenson ◽  
Hannele Uusitalo ◽  
Ari Hiltunen ◽  
Humphrey Gardner ◽  
...  
Keyword(s):  
Fracture Healing ◽  
Bone Fracture ◽  
Bone Fracture Healing ◽  
Callus Size ◽  
Deficient Mice ◽  
And Cartilage

scholarly journals Differentiation mechanisms of regeneration blastema cells during bone fracture healing

2018 ◽  
Vol 0 (2) ◽  
pp. 78-86
Author(s):  
Alexey Popsuishapka ◽  
Valeriy Litvishko ◽  
Nataliya Ashukina ◽  
Vitaliy Grigoryev ◽  
Olga Pidgaiska
Keyword(s):  
Fracture Healing ◽  
Bone Fracture ◽  
Bone Fracture Healing ◽  
Regeneration Blastema
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