scholarly journals Mechanical and viscoelastic characterization of polyvinyl alcohol (PVA) hydrogel membranes using the shaft-loaded blister test

2009 ◽  
Author(s):  
Edgar José Montiel-Rubio
Keyword(s):  
Polyvinyl Alcohol ◽  
Blister Test ◽  
Hydrogel Membranes ◽  
Pva Hydrogel

Mechanical Characterization of a Freestanding Polyvinyl Alcohol Hydrogel Membrane

2008 ◽  
Author(s):  
Edgar J. Montiel ◽  
Kai-Tak Wan
Keyword(s):  
Polyvinyl Alcohol ◽  
Biological Tissues ◽  
Material Strength ◽  
Hydrogel Membranes ◽  
Hydrogel Membrane ◽  
Standard Linear Solid ◽  
Standard Linear ◽  
Deformation Test

The following study presents two methods established for characterizing the mechanical properties of polyvinyl alcohol hydrogel membranes. The first one, an instant deformation test with an automated machine allowed the determination of the elastic properties of the material, while the second permitted the determination of the viscoelastic properties with the use of the standard linear solid model while confirming the previously found elastic results. This is not trivial as clearly old fashioned tests such as the ASTM standard tension test where grips are used to hold the sample are not feasible to perform due to the fragile characteristics of this kind material that resemble delicate biological tissues. The results obtained are consistent with previous publications, where different methods where used, but an increase in the material strength was also found as the number of freezing/thawing cycles increased.

Modification and Characterization of the Polyvinyl Alcohol (PVA) Hydrogel with Surfactant-cellulose Nanocrystal (S-CNC)

2020 ◽  
Vol 2 (2) ◽  
pp. 29-34
Author(s):  
Wonjong Lee ◽  
◽  
Meiyu Zhang ◽  
Jangjae Lee ◽  
Dongsup Song ◽  
...  
Keyword(s):  
Polyvinyl Alcohol ◽  
Cellulose Nanocrystal ◽  
Pva Hydrogel

Magnetic characterization of polyvinyl alcohol ferrogels and films

2007 ◽  
Vol 22 (8) ◽  
pp. 2211-2216 ◽  
Author(s):  
Rebeca Hernández ◽  
German López ◽  
Daniel López ◽  
Manuel Vázquez ◽  
Carmen Mijangos
Keyword(s):  
Magnetic Properties ◽  
Polyvinyl Alcohol ◽  
Polymer Network ◽  
Spinel Ferrites ◽  
Sulfonated Polystyrene ◽  
Magnetic Characterization ◽  
Final Structure ◽  
Cobalt Spinel ◽  
Pva Hydrogel

This study elucidates the tunability of the magnetic properties of cobalt spinel ferrites embedded in a polyvinyl alcohol (PVA) hydrogel by changing the structure of the polymer network. We report on the preparation and characterization of sPS-CoFe2O4 ferrofluid and PVA/sulfonated polystyrene (sPS)-CoFe2O4 ferrogels obtained by submitting the samples to a different number of freezing–thawing (F–T) cycles. The magnetic properties were evaluated and interpreted as a function of the PVA/sPS-CoFe2O4 composition and final structure of the ferrogels.

Early Failure of a Polyvinyl Alcohol Hydrogel Implant With Osteolysis and Foreign Body Reactions in an Ovine Model of Cartilage Repair

2021 ◽  
pp. 036354652110336
Author(s):  
Marta Cercone ◽  
Jacqueline Chevalier ◽  
John G. Kennedy ◽  
Andrew D. Miller ◽  
Lisa A. Fortier
Keyword(s):  
Computed Tomography ◽  
Foreign Body ◽  
Polyvinyl Alcohol ◽  
Failure Rate ◽  
Synovial Membrane ◽  
Quantitative Computed Tomography ◽  
Macrophage Infiltration ◽  
Ovine Model ◽  
Foreign Body Reactions ◽  
Pva Hydrogel

Background: Hemiarthroplasty using a polyvinyl alcohol (PVA) hydrogel synthetic implant has been suggested as a good alternative to arthrodesis for the treatment of hallux rigidus. However, failure rates as high as 20% have been recorded. Purpose: To characterize the pathological processes in bone, cartilage, and the synovial membrane after PVA hemiarthroplasty in an ovine model with 6 months of follow-up. Study Design: Controlled laboratory study. Methods: A unilateral osteochondral defect (8-mm diameter × 10-mm depth) was made in the medial femoral condyle in 6 sheep. Animals were randomized to receive a PVA implant (n = 4) or to have an empty defect (n = 2) and were monitored for 6 months. Patellofemoral radiographs were obtained at monthly intervals, and quantitative computed tomography was performed at the end of the study. After death, the joints were macroscopically evaluated and scored. Osteochondral and synovial membrane histological findings were assessed using modified Osteoarthritis Research Society International (OARSI) and aseptic lymphocyte-dominated vasculitis-associated lesion (ALVAL) scoring systems. Immunohistochemistry using Iba1 was performed to evaluate activated macrophage infiltration. Results: Overall, 2 sheep with PVA implants were euthanized at 1 and 5 months because of uncontrollable pain and lameness (failed implants). Quantitative computed tomography showed that sheep with failed implants had 2.1-fold more osteolysis than those with successful implants. The sheep with failed implants had osteoarthritis with extensive glycosaminoglycan loss and cartilage fibrillation of the condyle and opposing tibial surface on histological examination. A foreign body reaction with severe chronic lymphoplasmacytic and granulomatous inflammation with giant cells was detected surrounding the implant. The synovial membrane ALVAL score was 9 of 19 and 14 of 19 in failed implants with synovial hyperplasia and lymphoplasmacytic and macrophage infiltration. In contrast, the synovial membrane in successful implants and empty defects was normal (ALVAL score = 0/19). Immunolabeling for Iba1 in failed implants confirmed extensive and dense macrophage infiltration within the condyle and synovial membrane, with the highest immunoreactive score (9/9). Conclusion: PVA hydrogel implants had a 50% failure rate with uncontrollable pain, severe osteolysis, inflammation, and foreign body reactions. Clinical Relevance: The failure rate and pathological characteristics of the PVA implants suggest that their use should not be continued in human patients without further in vivo safety studies.

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