In Vitro Evaluation of Human Hand Tendon Ingrowth into A Synthetic Scaffold

2017 ◽  
Vol 22 (04) ◽  
pp. 429-434
Author(s):  
Shalimar Abdullah ◽  
Fadzlina Mohtar ◽  
Nordashima Abdul Shukor ◽  
Jamari Sapuan

Background: Synthetic scaffold has been used for tissue approximation and reconstructing damaged and torn ligaments. This study explores the ability of tendon ingrowth into a synthetic scaffold in vitro, evaluate growth characteristics, morphology and deposition of collagen matrix into a synthetic scaffold. Methods: Upper limb tendons were harvested with consent from patients with crush injuries and non-replantable amputations. These tendons (both extensor and flexor) measuring 1 cm are sutured to either side of a 0.5 cm synthetic tendon strip and cultured in growth medium. At 2, 4, 6 and 8 weeks, samples were fixed into paraffin blocks, cut and stained with haematoxylin-eosin (H&E) and Masson’s trichrome. Results: Minimal tendon ingrowth were seen in the first 2 weeks of incubation. However at 4 weeks, the cell ingrowth were seen migrating towards the junction between the tendon and the synthetic scaffold. This ingrowth continued to expand at 6 weeks and up to 8 weeks. At this point, the demarcation between human tendon and synthetic scaffold was indistinct. Conclusions: We conclude that tendon ingrowth composed of collagen matrix were able to proliferate into a synthetic scaffold in vitro.

Heliyon ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. e06517
Author(s):  
Lyudmila M. Mezhevikina ◽  
Dmitriy A. Reshetnikov ◽  
Maria G. Fomkina ◽  
Nurbol O. Appazov ◽  
Saltanat Zh. Ibadullayeva ◽  
...  

1980 ◽  
Vol 13 (11) ◽  
pp. 913-922 ◽  
Author(s):  
H. Schwerdt ◽  
A. Constantinesco ◽  
J. Chambron

Neurosurgery ◽  
1990 ◽  
Vol 27 (6) ◽  
pp. 921-928 ◽  
Author(s):  
Yoshihiro Yamamoto ◽  
David H. Bernanke ◽  
Robert R. Smith

Abstract The cause of chronic cerebral vasospasm after subarachnoid hemorrhage has been studied intensively, but it is still controversial whether the observable luminal narrowing should be attributed to the contraction of vascular smooth muscle cells or whether it results from some organic change in the wall. A proliferation of myointimal cells, accompanied by increased deposition of collagen, as well as myonecrosis, have been frequently observed several days after aneurysm rupture. Studies from our laboratory showed that these myointimal cells had characteristics identical to myofibroblasts. In this study, we quantitatively and morphologically examined the effect of cerebrospinal fluid on the ability of myofibroblasts to alter collagen matrices using an in vitro model. Myofibroblasts contract the collagen matrix by rearranging or compacting the framework of collagen fibers. Cerebrospinal fluid obtained from patients with recently ruptured aneurysms significantly accelerated lattice contraction, especially when the patient developed symptomatic vasospasm. This study suggests that myofibroblasts in the spastic artery can produce a contractile force that contributes to chronic vasospasm, tightening the proliferated collagen. Some unknown agent present in bloody cerebrospinal fluid accelerates the rearrangement of the collagen lattice by myofibroblasts, both of which have, until now, been considered non-contractile components.


Rheumatology ◽  
2014 ◽  
Vol 54 (2) ◽  
pp. 318-323 ◽  
Author(s):  
R. Mousavizadeh ◽  
L. Backman ◽  
R. G. McCormack ◽  
A. Scott

2001 ◽  
Vol 204 (3) ◽  
pp. 443-455
Author(s):  
C. Faucheux ◽  
S. Nesbitt ◽  
M. Horton ◽  
J. Price

Deer antlers are a rare example of mammalian epimorphic regeneration. Each year, the antlers re-grow by a modified endochondral ossification process that involves extensive remodelling of cartilage by osteoclasts. This study identified regenerating antler cartilage as a site of osteoclastogenesis in vivo. An in vitro model was then developed to study antler osteoclast differentiation. Cultured as a high-density micromass, cells from non-mineralised cartilage supported the differentiation of large numbers of osteoclast-like multinucleated cells (MNCs) in the absence of factors normally required for osteoclastogenesis. After 48 h of culture, tartrate-resistant acid phosphatase (TRAP)-positive mononuclear cells (osteoclast precursors) were visible, and by day 14 a large number of TRAP-positive MNCs had formed (783+/−200 per well, mean +/− s.e.m., N=4). Reverse transcriptase/polymerase chain reaction (RT-PCR) showed that receptor activator of NF κ B ligand (RANKL) and macrophage colony stimulating factor (M-CSF) mRNAs were expressed in micromass cultures. Antler MNCs have the phenotype of osteoclasts from mammalian bone; they expressed TRAP, vitronectin and calcitonin receptors and, when cultured on dentine, formed F-actin rings and large resorption pits. When cultured on glass, antler MNCs appeared to digest the matrix of the micromass and endocytose type I collagen. Matrix metalloproteinase-9 (MMP-9) may play a role in the resorption of this non-mineralised matrix since it is highly expressed in 100 % of MNCs. In contrast, cathepsin K, another enzyme expressed in osteoclasts from bone, is only highly expressed in resorbing MNCs cultured on dentine. This study identifies the deer antler as a valuable model that can be used to study the differentiation and function of osteoclasts in adult regenerating mineralised tissues.


2007 ◽  
Vol 73 (6) ◽  
pp. 1697-1703 ◽  
Author(s):  
N. Jain ◽  
R. Kohli ◽  
E. Cook ◽  
P. Gialanella ◽  
T. Chang ◽  
...  

ABSTRACT Biofilm formation (BF) in the setting of candiduria has not been well studied. We determined BF and MIC to antifungals in Candida spp. isolates grown from urine samples of patients and performed a retrospective chart review to examine the correlation with risk factors. A total of 67 Candida spp. isolates were grown from urine samples from 55 patients. The species distribution was C. albicans (54%), C. glabrata (36%), and C. tropicalis (10%). BF varied greatly among individual Candida isolates but was stable in sequential isolates during chronic infection. BF also depended on the growth medium and especially in C. albicans was significantly enhanced in artificial urine (AU) compared to RPMI medium. In nine of the C. albicans strains BF was 4- to 10-fold higher in AU, whereas in three of the C. albicans strains and two of the C. glabrata strains higher BF was measured in RPMI medium than in AU. Determination of the MICs showed that planktonic cells of all strains were susceptible to amphotericin B (AMB) and caspofungin (CASPO) and that three of the C. glabrata strains and two of the C. albicans strains were resistant to fluconazole (FLU). In contrast, all biofilm-associated adherent cells were resistant to CASPO and FLU. The biofilms of 14 strains (28%) were sensitive to AMB (MIC50 of <1 μg/ml). Correlation between degree of BF and MIC of AMB was not seen in RPMI grown biofilms but was present when grown in AU. A retrospective chart review demonstrated no correlation of known risk factors of candiduria with BF in AU or RPMI. We conclude that BF is a stable characteristic of Candida strains that varies greatly among clinical strains and is dependent on the growth medium. Resistance to AMB is associated with higher BF in AU, which may represent the more physiologic medium to test BF. Future studies should address whether in vitro BF can predict treatment failure in vivo.


2021 ◽  
Author(s):  
Shiva Pratap Singh ◽  
Suresh Dinkar Kharche ◽  
Manisha Pathak ◽  
Ravi Ranjan ◽  
Yogesh Kumar Soni ◽  
...  

Abstract The milieu of testicular germline stem cells (mGSCs) is characterized as low oxygen (O2) environment, whereas, there in-vitro expansion is typically performed under normoxia (20-21% O2). Here, we evaluated and compared the culture and multilineage differentiation characteristics of enriched (through differential platting and percoll density centrifugation) caprine mGSCs (cmGSCs) under hypoxic (5% O2) and normoxic (21% O2) culture conditions. For this, in addition to growth characteristics and population-doubling time (PDT); viability, proliferation, senescence, and expression of key-markers of adhesion (β-integrin and E-Cadherin) and stemness (OCT-4, THY-1 and UCHL-1) were evaluated and compared under normoxia and hypoxia. Moreover, the extent of multilineage differentiation (neurogenic, adipogenic, and chondrogenic differentiation) was assessed. The survival, viability and proliferation were significantly promoted and PDT was reduced (p < 0.05), thus yielding a higher number of viable cells with larger colonies under hypoxia. Furthermore, expression of stemness and adhesion markers was distinctly increased under lowered O2 condition. Conversely, the presence of differentiated regions and expression of differentiation specific key genes [C/EBPα (adipogenic), nestin and β-tubulin (neurogenic), and COL2A1 (chondrogenic)] were significantly (p < 0.05) reduced under hypoxic conditions. These data demonstrate that culturing cmGSCs under hypoxia augments the growth characteristics, and stemness but not the multilineage differentiation potential of cmGSCs as compared with normoxia. These data are important for the development of robust methodologies for ex-vivo expansion and lineage-committed differentiation of cmGSCs for clinical applications.


1992 ◽  
Vol 3 (4) ◽  
pp. 984-994
Author(s):  
M Ye ◽  
M Grant ◽  
M Sharma ◽  
L Elzinga ◽  
S Swan ◽  
...  

Autosomal dominant polycystic kidney disease (ADPKD) is characterized by progressive renal enlargement, culminating in renal insufficiency in over one half of affected individuals. The highly variable onset and clinical course of ADPKD may be due to factors extrinsic to the genetically defined renal cysts. In this study, cyst fluid samples from 12 nonazotemic and 18 azotemic ADPKD subjects were examined for in vitro biologic activity that promotes cellular proliferation and the secretion of fluid by renal epithelial monolayers, two pathogenetic mechanisms that have critical roles in the formation and the rate of expansion of renal cysts. Cyst fluid added to culture medium (final concentrations, 1 to 20%) caused Madin-Darby canine kidney cells and human kidney cortex (HKC) cells derived from primary cultures to form cysts in Type I collagen matrix. Cyst fluid stimulated the net transepithelial secretion of fluid by polarized monolayers composed of these same cells. Absolute levels of fluid secretory activity determined by MDCK bioassay were correlated directly with the rate of fluid secretion by HKC cell monolayers and with the extent of cyst formation by MDCK and HKC cells embedded in collagen matrix. The secretory activity of urine was negligible; secretory activity was detectable in the serum of normal and ADPKD subjects, but the levels were much lower than in cyst fluid. cAMP agonists prostaglandins E1 and E2, arginine vasopressin, and 8-Br-cAMP stimulated fluid secretion by MDCK and HKC monolayers, but these substances did not cause HKC cells to form cysts in collagen matrix, whereas cyst fluid did. Among other naturally occurring growth factors and autacoids, only epidermal growth factor and transforming growth factor alpha stimulated cyst formation by HKC cells; however, the capacity of cyst fluid to stimulate fluid secretion was not affected by treatment with antiserum to epidermal growth factor. It was concluded that potent, and possibly unique, substances in the cyst fluids of individuals with ADPKD support and augment biologic processes in renal epithelial cells that may be important in the promotion of progressive cyst expansion.


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