The Growth of Cartilage Cells in Vitro and the Effect of Intermittent Compressive Force. A Histological Evaluation

1987 ◽  
Vol 16 (2) ◽  
pp. 187-196 ◽  
Author(s):  
J. P. Veldhuijzen ◽  
A. H. Huisman ◽  
J. P.W. Vermeiden ◽  
B. Prahl-Andersen
Biomolecules ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 932
Author(s):  
Julia Brockhaus ◽  
Rogerio B. Craveiro ◽  
Irma Azraq ◽  
Christian Niederau ◽  
Sarah K. Schröder ◽  
...  

Human Periodontal Ligament Fibroblasts (hPDLF), as part of the periodontal apparatus, modulate inflammation, regeneration and bone remodeling. Interferences are clinically manifested as attachment loss, tooth loosening and root resorption. During orthodontic tooth movement (OTM), remodeling and adaptation of the periodontium is required in order to enable tooth movement. hPDLF involvement in the early phase-OTM compression side was investigated for a 72-h period through a well-studied in vitro model. Changes in the morphology, cell proliferation and cell death were analyzed. Specific markers of the cell cycle were investigated by RT-qPCR and Western blot. The study showed that the morphology of hPDLF changes towards more unstructured, unsorted filaments under mechanical compression. The total cell numbers were significantly reduced with a higher cell death rate over the whole observation period. hPDLF started to recover to pretreatment conditions after 48 h. Furthermore, key molecules involved in the cell cycle were significantly reduced under compressive force at the gene expression and protein levels. These findings revealed important information for a better understanding of the preservation and remodeling processes within the periodontium through Periodontal Ligament Fibroblasts during orthodontic tooth movement. OTM initially decelerates the hPDLF cell cycle and proliferation. After adapting to environmental changes, human Periodontal Ligament Fibroblasts can regain homeostasis of the periodontium, affecting its reorganization.


2021 ◽  
Vol 22 (1) ◽  
pp. 394
Author(s):  
Simone Krueger ◽  
Alexander Riess ◽  
Anika Jonitz-Heincke ◽  
Alina Weizel ◽  
Anika Seyfarth ◽  
...  

In cell-based therapies for cartilage lesions, the main problem is still the formation of fibrous cartilage, caused by underlying de-differentiation processes ex vivo. Biophysical stimulation is a promising approach to optimize cell-based procedures and to adapt them more closely to physiological conditions. The occurrence of mechano-electrical transduction phenomena within cartilage tissue is physiological and based on streaming and diffusion potentials. The application of exogenous electric fields can be used to mimic endogenous fields and, thus, support the differentiation of chondrocytes in vitro. For this purpose, we have developed a new device for electrical stimulation of chondrocytes, which operates on the basis of capacitive coupling of alternating electric fields. The reusable and sterilizable stimulation device allows the simultaneous use of 12 cavities with independently applicable fields using only one main supply. The first parameter settings for the stimulation of human non-degenerative chondrocytes, seeded on collagen type I elastin-based scaffolds, were derived from numerical electric field simulations. Our first results suggest that applied alternating electric fields induce chondrogenic re-differentiation at the gene and especially at the protein level of human de-differentiated chondrocytes in a frequency-dependent manner. In future studies, further parameter optimizations will be performed to improve the differentiation capacity of human cartilage cells.


2015 ◽  
Vol 03 (02) ◽  
pp. 080-084
Author(s):  
Vijay Singh ◽  
Poonam Bogra ◽  
Saurabh Gupta ◽  
Navneet Kukreja ◽  
Neha Gupta

AbstractFracture resistance of endodontically treated teeth restored with post. Aims: This study aims to compare the fracture resistance of endodontically treated teeth restored with resin fiber and stainless steel post. Commercially available prefabricated resin fiber post(Dentsply Maillefer Easy Post), prefabricated stainless steel post(Coltene/Whaledent Parapost) were used. Methods and Material: Forty five maxillary central incisors were obturated and divided into 3 groups: Control Group (Group I) without any post (n = 15), Resin Fiber Post Group (Group II) (n = 15) and Stainless Steel Post Group (Group III) (n = 15). In all Groups except control group, post space was prepared; a post was cemented, and a core build-up was provided. All the specimens were subjected to compressive force under a universal testing machine until fracture. Statistical analysis used: The results were analyzed using the variable analysis test (ANOVA). Results: One-way analysis of variance revealed significant difference among test groups. The control group demonstrated highest fracture resistance (925.2183 N), followed by the resin fiber post group (486.7265 N) and stainless steel post group (423.539N). Conclusions: Teeth restored with resin fiber post showed higher fracture resistance values than prefabricated stainless steel post.


1987 ◽  
Vol 262 (32) ◽  
pp. 15490-15495
Author(s):  
J Klein-Nulend ◽  
J P Veldhuijzen ◽  
R J van de Stadt ◽  
G P van Kampen ◽  
R Kuijer ◽  
...  

2009 ◽  
Vol 88 (8) ◽  
pp. 752-756 ◽  
Author(s):  
A. Miyagawa ◽  
M. Chiba ◽  
H. Hayashi ◽  
K. Igarashi

During orthodontic tooth movement, the activation of the vascular system in the compressed periodontal ligament (PDL) is an indispensable process in tissue remodeling. We hypothesized that compressive force would induce angiogenesis of PDL through the production of vascular endothelial growth factor (VEGF). We examined the localization of VEGF in rat periodontal tissues during experimental tooth movement in vivo, and the effects of continuous compressive force on VEGF production and angiogenic activity in human PDL cells in vitro. PDL cells adjacent to hyalinized tissue and alveolar bone on the compressive side showed marked VEGF immunoreactivity. VEGF mRNA expression and production in PDL cells increased, and conditioned medium stimulated tube formation. These results indicate that continuous compressive force enhances VEGF production and angiogenic activity in PDL cells, which may contribute to periodontal remodeling, including angiogenesis, during orthodontic tooth movement.


Pharmaceutics ◽  
2018 ◽  
Vol 10 (4) ◽  
pp. 227 ◽  
Author(s):  
Bayan Darwesh ◽  
Hibah Aldawsari ◽  
Shaimaa Badr-Eldin

(1) Background: Fluconazole, used orally for vaginal candidiasis, has reported gastrointestinal side effects. Therefore, researchers directed towards the drug vaginal delivery. However, vaginal delivery is limited by poor retention and leakage. Thus, this work aimed at exploring chitosan/anion polyelectrolyte complex (PEC) for the formulation of fluconazole vaginal inserts with controlled release and appreciable mucoadhesion. (2) Methods: PECs were prepared and assessed for interactions. Fluconazole PEC based vaginal inserts were prepared by lyophilization using mannitol. 3151 factorial design was applied to investigate the effect of the anion type and Chitosan/anion ratio on the inserts mucoadhesion and release properties. The optimized insert [based on 5:5 chitosan: anionic polymer (sodium alginate)] release was modulated by the release retardant; Compritol® 888. The selected formulation was subjected to microbiological and histological evaluation. (3) Results: Fluconazole inserts showed satisfactory drug content, acceptable friability percentages and highest swelling indices at six hours. Statistical analysis showed significant effect of the studied factors on detachment force and release properties. Microbiological assays revealed significantly higher antifungal activity of inserts compared to fluconazole solution. Reduced inflammatory cells were confirmed by histological evaluation. (4) Conclusion: CH/Alg based vaginal insert could be a promising platform for vaginal delivery of antifungal drugs used for vaginal candidiasis treatment.


1922 ◽  
Vol 36 (4) ◽  
pp. 379-384 ◽  
Author(s):  
Albert Fischer

1. A strain of cartilage cells, obtained from the pars cartilago scleræ of the eye of chick embryos, has been cultivated for more than 3 months in vitro. 2. The initial growth of the cartilage was possible only on the free surface of the coagulum. 3. The hyaline substance disappeared during cultivation in vitro. The succeeding stages of a transformation from small, lymphocyte-like cells into large, spindle-shaped cells were observed. The cartilage cells were spindle-shaped and grew in close contact, forming thin membranes. In surface-grown cartilage cells, the nucleus, usually containing one large nucleolus, stained less deeply than the cytoplasm. 4. The rate of growth of cartilage was slower than that of fibroblasts and epithelium. After cultivation on the surface of the coagulum, the cartilage cells could multiply even when embedded in the coagulum. But their growth was less extensive and uniform.


2018 ◽  
Vol 49 (6) ◽  
pp. 2304-2319 ◽  
Author(s):  
Zhenhui Lu ◽  
Qin Liu ◽  
Lei Liu ◽  
Huayu Wu ◽  
Li Zheng ◽  
...  

Background/Aims: 3, 4, 5-trihydroxy-N-{4-[(5-methylisoxazol-3-yl) sulfamoyl] phenyl} benzamide (JEZTC), synthesized from gallic acid (GA) and sulfamethoxazole (SMZ), was reported with chondroprotective effects. However, the effects of JEZTC on osteoarthritis (OA) are still unclear. The goal of this study was to investigate the anti-osteoarthritic properties of JEZTC on interleukin-1-beta (IL-1β) stimulated chondrocytes in vitro and a rabbit anterior cruciate ligament transaction (ACLT) OA model in vivo. Methods: Changes in matrix metalloproteinases (MMPs) and apoptosis genes (bax, caspase 3 and tnf-α) and OA-specific protein (MMP-1) expression in vitro and in vivo were detected by real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and immunohistochemistry. The production of reactive oxygen species (ROS) were investigated upon the treatment of JEZTC in chondrocytes processed with IL-1β in vitro and OA in vivo. Effect of JEZTC on OA was further studied by the macroscopic and histological evaluation and scores. The key proteins in signaling pathways inMAPK/P38, PI3KAkt and NF-κB also determined using western blot (WB) analysis. Results: JEZTC could significantly suppress the expression of MMPs and intracellular ROS, while meaningfully increase the gene expression of tissue inhibitor of metalloproteinase-1 (TIMP-1). Moreover, there was less cartilage degradation in JEZTC group compared with the phosphate-buffered saline (PBS) group in vivo. Results also indicated that JEZTC exerts effect on OA by regulating MAPKs and PI3K/Akt signaling pathways to activate NF-κB pathway, leading to the down-regulation of MMPs. The chondro-protective effect of JEZTC may be related with its ability to inhibit chondrocyte apoptosis by reduction of ROS production. Conclusion: JEZTC may be a possible therapeutic agent in the treatment of OA.


Author(s):  
Mingxiao Liu ◽  
Xiangyu Han ◽  
Hongyun Liu ◽  
Danyang Chen ◽  
Yue Li ◽  
...  
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