Development of Polyvinyl Alcohol-Hydrogel (PVA-H) Shields with a High Water Content for Tendon Injury Repair

2001 ◽  
Vol 26 (5) ◽  
pp. 436-440 ◽  
Author(s):  
M. KOBAYASHI ◽  
J. TOGUCHIDA ◽  
M. OKA
Keyword(s):  
Polyvinyl Alcohol ◽  
Water Content ◽  
Flexor Tendon ◽  
Adhesion Formation ◽  
Tendon Repair ◽  
High Water ◽  
Tendon Injury ◽  
Surrounding Tissue ◽  
High Water Content ◽  
Injury Repair

The main problem in tendon repair is adhesion formation between the tendon and surrounding tissue. To prevent this, we have developed adhesion preventive shields using polyvinyl alcohol hydrogel (PVA-H) with 90% water content. This implant experiment used the deep flexor tendon of the 3rd toe of the domestic fowl. Injured tendons shielded with PVA-H healed within about 3 weeks without adhesion to the surrounding tissues. Neither breakage of the PVA-H shield itself nor infection or degeneration in the surrounding tissue was observed. These results show that tendon is capable of intrinsic repair, and was able to regenerate using synovial nutrition through the PVA-H. The high water content of PVA-H may be clinically useful and applicable to adhesion preventive shields for tendon repair.

scholarly journals An Overview of the Management of Flexor Tendon Injuries

2012 ◽  
Vol 6 (1) ◽  
pp. 28-35 ◽  
Author(s):  
M Griffin ◽  
S Hindocha ◽  
D Jordan ◽  
M Saleh ◽  
W Khan
Keyword(s):  
Flexor Tendon ◽  
Current Knowledge ◽  
Adhesion Formation ◽  
Tendon Repair ◽  
Tendon Injury ◽  
Tendon Injuries ◽  
Flexor Tendon Repair ◽  
Flexor Tendon Injury ◽  
Post Surgery ◽  
Flexor Tendon Injuries

Flexor tendon injuries still remain a challenging condition to manage to ensure optimal outcome for the patient. Since the first flexor tendon repair was described by Kirchmayr in 1917, several approaches to flexor tendon injury have enabled successful repairs rates of 70-90%. Primary surgical repair results in better functional outcome compared to secondary repair or tendon graft surgery. Flexor tendon injury repair has been extensively researched and the literature demonstrates successful repair requires minimal gapping at the repair site or interference with tendon vascularity, secure suture knots, smooth junction of tendon end and having sufficient strength for healing. However, the exact surgical approach to achieve success being currently used among surgeons is still controversial. Therefore, this review aims to discuss the results of studies demonstrating the current knowledge regarding the optimal approach for flexor tendon repair. Post-operative rehabilitation for flexor tendon surgery is another area, which has caused extensive debate in hand surgery. The trend to more active mobilisation protocols seems to be favoured but further study in this area is needed to find the protocol, which achieves function and gliding but avoids rupture of the tendons. Lastly despite success following surgery complications commonly still occur post surgery, including adhesion formation, tendon rupture and stiffness of the joints. Therefore, this review aims to discuss the appropriate management of these difficulties post surgery. New techniques in management of flexor tendon will also be discussed including external laser devices, addition of growth factors and cytokines.

High-water-content graphene oxide/polyvinyl alcohol hydrogel with excellent mechanical properties

2014 ◽  
Vol 2 (27) ◽  
pp. 10508-10515 ◽  
Author(s):  
Yifu Huang ◽  
Mingqiu Zhang ◽  
Wenhong Ruan
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
Polyvinyl Alcohol ◽  
Water Content ◽  
High Water ◽  
High Water Content ◽  
Cross Linking ◽  
Freeze Thaw

Boron-cross-linked graphene oxide/polyvinyl alcohol (B-GO/PVA) hydrogels with high-water-content and excellent mechanical properties are prepared by freeze/thaw and boron cross-linking methods.

Evaluation of an Immunoisolation Membrane Formed by Incorporating a Polyvinyl Alcohol Hydrogel within a Microporous Filter Support

1997 ◽  
Vol 6 (6) ◽  
pp. 585-595 ◽  
Author(s):  
Andrew R. Baker ◽  
Ronald L. Fournier ◽  
Jeffrey G. Sarver ◽  
Jennifer L. Long ◽  
Peter J. Goldblatt ◽  
...  
Keyword(s):  
Polyvinyl Alcohol ◽  
Water Content ◽  
Structural Integrity ◽  
High Water ◽  
Membrane Properties ◽  
High Water Content ◽  
Hybrid Hydrogel ◽  
Wide Range ◽  
Pva Hydrogel

An immunoisolation membrane formed by incorporating a high water content polyvinyl alcohol (PVA) hydrogel into a microporous polyether sulfone (PES) filter has been investigated in this study. The PVA hydrogel is formed in situ within the filter pores via glutaraldehyde (GA) crosslinking under acidic conditions. The tortuous nature of the microporous filter pores securely anchors the embedded hydrogel to provide excellent structural integrity. The high void fraction of the PES filter support (>80%) and high water content of the PVA hydrogel (>85% water by weight) allow excellent solute transport rates, while an appropriate level of glutaraldehyde crosslinking supplies the required molecular size selectivity. In vitro permeability measurements made with solutes covering a wide range of molecular sizes demonstrate high transport rates for small nutrient molecules with rapidly diminishing permeabilities above a molecular weight of approximately 1,000 Dalton. Implantation experiments show that the membrane properties are not deleteriously affected by prolonged in vivo exposure or common sterilization techniques. Thus, this hybrid hydrogel/filter membrane system offers a promising approach to the immunoisolation of implanted cells.

Hydrogels as Antibacterial Biomaterials

2018 ◽  
Vol 24 (8) ◽  
pp. 843-854 ◽  
Author(s):  
Weiguo Xu ◽  
Shujun Dong ◽  
Yuping Han ◽  
Shuqiang Li ◽  
Yang Liu
Keyword(s):  
Mechanical Properties ◽  
Drug Delivery ◽  
Tissue Engineering ◽  
Water Content ◽  
Oxygen Permeability ◽  
Structural Diversity ◽  
High Water ◽  
Clinical Applications ◽  
High Water Content ◽  
Biomedical Field

Hydrogels, as a class of materials for tissue engineering and drug delivery, have high water content and solid-like mechanical properties. Currently, hydrogels with an antibacterial function are a research hotspot in biomedical field. Many advanced antibacterial hydrogels have been developed, each possessing unique qualities, namely high water swellability, high oxygen permeability, improved biocompatibility, ease of loading and releasing drugs and structural diversity. In this article, an overview is provided on the preparation and applications of various antibacterial hydrogels. Furthermore, the prospects in biomedical researches and clinical applications are predicted.

Microwave-Induced Thermoacoustic Imaging for Embedded Explosives Detection in High-Water Content Medium

2019 ◽  
Vol 67 (7) ◽  
pp. 4803-4810 ◽  
Author(s):  
Xiong Wang ◽  
Tao Qin ◽  
Yexian Qin ◽  
Ahmed H. Abdelrahman ◽  
Russell S. Witte ◽  
...  
Keyword(s):  
Water Content ◽  
High Water ◽  
Explosives Detection ◽  
High Water Content ◽  
Thermoacoustic Imaging

scholarly journals Deep mantle melting, global water circulation and its implications for the stability of the ocean mass

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Shun-ichiro Karato ◽  
Bijaya Karki ◽  
Jeffrey Park
Keyword(s):  
Phase Transformation ◽  
Water Content ◽  
Sea Level ◽  
High Water ◽  
Water Circulation ◽  
Mantle Melting ◽  
High Water Content ◽  
Mineral Physics ◽  
Deep Mantle ◽  
Global Water

AbstractOceans on Earth are present as a result of dynamic equilibrium between degassing and regassing through the interaction with Earth’s interior. We review mineral physics, geophysical, and geochemical studies related to the global water circulation and conclude that the water content has a peak in the mantle transition zone (MTZ) with a value of 0.1–1 wt% (with large regional variations). When water-rich MTZ materials are transported out of the MTZ, partial melting occurs. Vertical direction of melt migration is determined by the density contrast between the melts and coexisting minerals. Because a density change associated with a phase transformation occurs sharply for a solid but more gradually for a melt, melts formed above the phase transformation depth are generally heavier than solids, whereas melts formed below the transformation depth are lighter than solids. Consequently, hydrous melts formed either above or below the MTZ return to the MTZ, maintaining its high water content. However, the MTZ water content cannot increase without limit. The melt-solid density contrast above the 410 km depends on the temperature. In cooler regions, melting will occur only in the presence of very water-rich materials. Melts produced in these regions have high water content and hence can be buoyant above the 410 km, removing water from the MTZ. Consequently, cooler regions of melting act as a water valve to maintain the water content of the MTZ near its threshold level (~ 0.1–1.0 wt%). Mass-balance considerations explain the observed near-constant sea-level despite large fluctuations over Earth history. Observations suggesting deep-mantle melting are reviewed including the presence of low-velocity anomalies just above and below the MTZ and geochemical evidence for hydrous melts formed in the MTZ. However, the interpretation of long-term sea-level change and the role of deep mantle melting in the global water circulation are non-unique and alternative models are reviewed. Possible future directions of studies on the global water circulation are proposed including geodynamic modeling, mineral physics and observational studies, and studies integrating results from different disciplines.

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