scholarly journals Optimization and Validation of a Human Ex Vivo Femoral Head Model for Preclinical Cartilage Research and Regenerative Therapies

Cartilage ◽  
2020 ◽  
pp. 194760352093453
Author(s):  
Katarzyna Styczynska-Soczka ◽  
Anish K. Amin ◽  
A. Hamish W. Simpson ◽  
Andrew C. Hall
Keyword(s):  
Surface Roughness ◽  
Femoral Head ◽  
Alcian Blue ◽  
Cartilage Repair ◽  
Ex Vivo ◽  
Chondrocyte Viability ◽  
Femoral Heads ◽  
Regenerative Therapies ◽  
Picrosirius Red ◽  
And Cartilage

Objective Articular cartilage is incapable of effective repair following injury or during osteoarthritis. While there have been developments in cartilage repair technologies, there is a need to advance biologically relevant models for preclinical testing of biomaterial and regenerative therapies. This study describes conditions for the effective ex vivo culture of the whole human femoral head. Design Fresh, viable femoral heads were obtained from femoral neck fractures and cultured for up to 10 weeks in (a) Dulbecco’s modified Eagle’s medium (DMEM); (b) DMEM + mixing; (c) DMEM + 10% human serum (HS); (d) DMEM + 10% HS + mixing. The viability, morphology, volume, and density of fluorescently labelled in situ chondrocytes and cartilage surface roughness were assessed by confocal microscopy. Cartilage histology was studied for glycosaminoglycan content using Alcian blue and collagen content using picrosirius red. Results Chondrocyte viability remained at >95% in DMEM + 10% HS. In DMEM alone, viability remained high for ~4 weeks and then declined. For the other conditions, superficial zone chondrocyte viability fell to <35% at 10 weeks with deeper zones being relatively unaffected. In DMEM + 10% HS at 10 weeks, the number of chondrocytes possessing cytoplasmic processes increased compared with DMEM ( P = 0.017). Alcian blue labeling decreased ( P = 0.02) and cartilage thinned ( P ≤ 0.05); however, there was no change to surface roughness, chondrocyte density, chondrocyte volume, or picrosirius red labeling ( P > 0.05). Conclusions In this ex vivo model, chondrocyte viability was maintained in human femoral heads for up to 10 weeks in culture, a novel finding not previously reported. This human model could prove invaluable for the exploration, development, and assessment of preclinical cartilage repair and regenerative therapies.

In Vivo Observations of Hydraulic Stiffening in the Canine Femoral Head

1997 ◽  
Vol 119 (1) ◽  
pp. 103-108 ◽  
Author(s):  
J. A. Ochoa ◽  
A. P. Sanders ◽  
T. W. Kiesler ◽  
D. A. Heck ◽  
J. P. Toombs ◽  
...  
Keyword(s):  
Femoral Head ◽  
Femoral Neck ◽  
Boundary Conditions ◽  
Mechanical Response ◽  
Ex Vivo ◽  
Femoral Cortex ◽  
Hind Limbs ◽  
Femoral Heads ◽  
Fluid Boundary

The role that intertrabecular contents and their boundary conditions have on the dynamic mechanical response of canine femoral heads was investigated in vivo. Femoral heads from paired intact hind limbs of canine specimens were subjected to a sinusoidal strain excitation, at physiologic frequencies, in the cranio-caudal direction. The fluid boundary conditions for the contralateral limbs were changed by predrilling through the lateral femoral cortex and into the femoral neck. The drilling procedure did not invade the head itself. This femoral head fluid boundary alteration reduced the stiffness by 19 percent for testing at 1 Hz. The results of this study demonstrate that fluid stiffening occurs in vivo as previously observed ex vivo.

Holding Power of Orthopaedic Screws in Bovine Femoral Heads

1993 ◽  
Vol 06 (03) ◽  
pp. 160-162 ◽  
Author(s):  
M. J. Ulm ◽  
D. G. Wilson
Keyword(s):  
Femoral Head ◽  
Cannulated Screws ◽  
Cancellous Screw ◽  
Holding Power ◽  
Cortical Screw ◽  
Femoral Heads ◽  
Cancellous Screws ◽  
Physeal Fractures

SummaryFemoral capital physeal fractures have been successfully repaired using 7.0 mm cannulated screws. The holding power of 7.0 mm cannulated screws was compared to the holding power of 5.5 mm cortical screws and 6.5 mm cancellous screws using paired bovine femoral heads. The 7.0 mm cannulated screw’s holding power was superior to the 6.5 mm cancellous screw and similar to that of the 5.5 mm cortical screw.When placed in the bovine femoral head, 7.0 mm cannulated screws have holding power greater than 6.5 mm cancellous screws and similar to 5.5 mm cortical screws.

Anti-Inflammatory Effects of Novel Standardized Platelet Rich Plasma Releasates on Knee Osteoarthritic Chondrocytes and Cartilage in vitro

2019 ◽  
Vol 20 (11) ◽  
pp. 920-933 ◽  
Author(s):  
Lucía Gato-Calvo ◽  
Tamara Hermida-Gómez ◽  
Cristina R. Romero ◽  
Elena F. Burguera ◽  
Francisco J. Blanco
Keyword(s):  
Gene Expression ◽  
Ex Vivo ◽  
Platelet Rich Plasma ◽  
Cartilage Explants ◽  
Ex Vivo Model ◽  
Chondrocyte Viability ◽  
Platelet Concentration ◽  
The Absolute ◽  
Anti Inflammatory

Background: Platelet Rich Plasma (PRP) has recently emerged as a potential treatment for osteoarthritis (OA), but composition heterogeneity hampers comparison among studies, with the result that definite conclusions on its efficacy have not been reached. Objective: 1) To develop a novel methodology to prepare a series of standardized PRP releasates (PRP-Rs) with known absolute platelet concentrations, and 2) To evaluate the influence of this standardization parameter on the anti-inflammatory properties of these PRP-Rs in an in vitro and an ex vivo model of OA. Methods: A series of PRPs was prepared using the absolute platelet concentration as the standardization parameter. Doses of platelets ranged from 0% (platelet poor plasma, PPP) to 1.5·105 platelets/µl. PRPs were then activated with CaCl2 to obtain releasates (PRP-R). Chondrocytes were stimulated with 10% of each PRP-R in serum-free culture medium for 72 h to assess proliferation and viability. Cells were co-stimulated with interleukin (IL)-1β (5 ng/ml) and 10% of each PRP-R for 48 h to determine the effects on gene expression, secretion and intra-cellular content of common markers associated with inflammation, catabolism and oxidative stress in OA. OA cartilage explants were co-stimulated with IL-1β (5 ng/ml) and 10% of either PRP-R with 0.75·105 platelets/µl or PRP-R with 1.5·105 platelets/µl for 21 days to assess matrix inflammatory degradation. Results: Chondrocyte viability was not affected, and proliferation was dose-dependently increased. The gene expression of all pro-inflammatory mediators was significantly and dose-independently reduced, except for that of IL-1β and IL-8. Immunoblotting corroborated this effect for inducible NO synthase (NOS2). Secreted matrix metalloproteinase-13 (MMP-13) was reduced to almost basal levels by the PRP-R from PPP. Increasing platelet dosage led to progressive loss to this anti-catabolic ability. Safranin O and toluidine blue stains supported the beneficial effect of low platelet dosage on cartilage matrix preservation. Conclusion: We have developed a methodology to prepare PRP releasates using the absolute platelet concentration as the standardization parameter. Using this approach, the composition of the resulting PRP derived product is independent of the donor initial basal platelet count, thereby allowing the evaluation of its effects objectively and reproducibly. In our OA models, PRP-Rs showed antiinflammatory, anti-oxidant and anti-catabolic properties. Platelet enrichment could favor chondrocyte proliferation but is not necessary for the above effects and could even be counter-productive.

Gene Therapy to Enhance Bone and Cartilage Repair in Orthopaedic Surgery

2018 ◽  
Vol 18 (3) ◽  
pp. 154-170 ◽  
Author(s):  
Sofia Bougioukli ◽  
Christopher H. Evans ◽  
Ram K. Alluri ◽  
Steven C. Ghivizzani ◽  
Jay R. Lieberman
Keyword(s):  
Gene Therapy ◽  
Cartilage Repair ◽  
Orthopaedic Surgery ◽  
And Cartilage

scholarly journals Combination of histochemical analyses and micro-MRI reveals regional changes of the murine cervix in preparation for labor

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Antara Chatterjee ◽  
Rojan Saghian ◽  
Anna Dorogin ◽  
Lindsay S. Cahill ◽  
John G. Sled ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Diffusion Tensor ◽  
Ex Vivo ◽  
Muscle Cells ◽  
Pregnant Mouse ◽  
Collagen Fibers ◽  
Muscular Layer ◽  
Tissue Organization ◽  
Picrosirius Red

AbstractThe cervix is responsible for maintaining pregnancy, and its timely remodeling is essential for the proper delivery of a baby. Cervical insufficiency, or “weakness”, may lead to preterm birth, which causes infant morbidities and mortalities worldwide. We used a mouse model of pregnancy and term labor, to examine the cervical structure by histology (Masson Trichome and Picrosirius Red staining), immunohistochemistry (Hyaluronic Acid Binding Protein/HABP), and ex-vivo MRI (T2-weighted and diffusion tensor imaging), focusing on two regions of the cervix (i.e., endocervix and ectocervix). Our results show that mouse endocervix has a higher proportion of smooth muscle cells and collagen fibers per area, with more compact tissue structure, than the ectocervix. With advanced gestation, endocervical changes, indicative of impending delivery, are manifested in fewer smooth muscle cells, expansion of the extracellular space, and lower presence of collagen fibers. MRI detected three distinctive zones in pregnant mouse endocervix: (1) inner collagenous layer, (2) middle circular muscular layer, and (3) outer longitudinal muscular layer. Diffusion MRI images detected changes in tissue organization as gestation progressed suggesting the potential application of this technique to non-invasively monitor cervical changes that precede the onset of labor in women at risk for preterm delivery.

Optimal parameters of abrasive flow finishing for hip joint implants

2021 ◽  
pp. 095440542199561
Author(s):  
Yahya Choopani ◽  
Mohsen Khajehzadeh ◽  
Mohammad Reza Razfar
Keyword(s):  
Surface Roughness ◽  
Standard Deviation ◽  
Femoral Head ◽  
Hip Joint ◽  
Spherical Shape ◽  
Shape Deviation ◽  
Head Surface ◽  
Joint Implants ◽  
Finishing Processes ◽  
Abrasive Flow Finishing

Total hip arthroplasty (THA) is one of the most well-known orthopedic surgeries in the world which involves the substitution of the natural hip joint by prostheses. In this process, the surface roughness of the femoral head plays a pivotal role in the performance of hip joint implants. In this regard, the nano-finishing of the femoral head of the hip joint implants to achieve a uniform surface roughness with the lowest standard deviation is a major challenge in the conventional and advanced finishing processes. In the present study, the inverse replica fixture technique was used for automatic finishing in the abrasive flow finishing (AFF) process. For this aim, an experimental setup of the AFF process was designed and fabricated. After the tests, experimental data were modeled and optimized to achieve the minimum surface roughness in the ASTM F138 (SS 316L) femoral head of the hip joint through the use of response surface methodology (RSM). The results confirmed uniform surface roughness up to the range of 0.0203 µm with a minimum standard deviation of 0.00224 for the femoral head. Moreover, the spherical shape deviation of the femoral head was achieved in the range of 7 µm. The RSM results showed a 99.71% improvement in the femoral head surface roughness (0.0007) µm under the optimized condition involving the extrusion pressure of 9.10 MPa, the number of finishing cycles of 95, and SiC abrasive mesh number of 1000.

Injectable hydrogels for bone and cartilage repair

2012 ◽  
Vol 7 (2) ◽  
pp. 024105 ◽  
Author(s):  
Ashley A Amini ◽  
Lakshmi S Nair
Keyword(s):  
Cartilage Repair ◽  
Injectable Hydrogels ◽  
And Cartilage

A comparison of 2 cementing techniques in hip resurfacing using human femoral heads

2021 ◽  
pp. 112070002199706
Author(s):  
Sarah J Shiels ◽  
Martin Williams ◽  
Gordon C Bannister ◽  
Richard P Baker
Keyword(s):  
Femoral Head ◽  
Femoral Component ◽  
Bubble Formation ◽  
Young Male ◽  
Cement Mantle ◽  
Hip Resurfacing ◽  
Air Bubble ◽  
Low Viscosity ◽  
Femoral Heads ◽  
Group 2

Introduction: Hip resurfacing remains a valid option in young male patients. The creation of the optimum cement mantle aids fixation of the femoral component. If the cement mantle is too thick the prosthesis can remain proud leading to early failure or if it penetrates too far into the femoral head, it may cause osteonecrosis. Method: 18 of 96 femoral heads collected from patients undergoing total hip arthroplasty were matched for their surface porosity. They were randomly allocated into 2 different cementing groups. Group 1 had the traditional bolus of cement technique, while group 2 had a modified cementing technique (swirl) where the inside of the femoral component was lined with an even layer of low viscosity cement. Results: The traditional bolus technique had significantly greater cement mantle thickness in 3 of 4 zones of penetration ( p = 0.002), greater and larger air bubble formation (6 of 9 in bolus technique vs. 1 in 9 in swirl technique, p = 0.05) and more incomplete cement mantles compared with the swirl technique. There was no relationship to femoral head porosity. Conclusion: The swirl technique should be used to cement the femoral component in hip resurfacing. Long-term clinical studies would conform if this translates into increased survivorship of the femoral component.

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