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The Study on Relationship between Viscoelastic Properties and Drug Release of Wound Dress Polyvinyl Alcohol Hydrogel

Rezvan, Gelareh | 2016

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  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 49695 (07)
  4. University: Sharif University of Technology
  5. Department: Materials Science and Engineering
  6. Advisor(s): Bagheri, Reza; Pircheraghi, Gholamreza
  7. Abstract:
  8. Wound is a defect or failure in the skin texture which occurs as a result of physical or heat injuries or physiological conditions. The wound dress as a temporary cover can improve wound healing process and due to the unique properties, hydrogels have become appropriate choice for this application. Hydrogel’s structure allows drug to be loaded in the wound dress. Hydrogel wound dress should have adequate fluidity to cover wound’s bed and make full contact with the skin. Sufficient cohesion and strength is also necessary to allow the wound dress to remove from wound completely. Therefore, the study on the viscoelastic properties of hydrogel is important. In this study, polyvinyl alcohol (PVA)- borax hydrogel was evaluated for wound dressing application. Samples of hydrogels containing 4 wt% of PVA and had borax: PVA in the range of 0.1 to 1 were prepared. The viscoelastic properties of samples were measured in oscillatory shear flow using rheometer in 25 and 37 oC. By increasing the borax: PVA in the range of 0.1 to 0.25, the storage modulus and complex viscosity of hydrogels increased by 1.5 to 1.8 folds, respectively. With further increase in borax the amount of borax storage modulus and coplex viscosity dropped. This result reveals that there is the optimum ratio of borax: PVA to achieve the maximum viscoelastic properties which is equal to 0.25. To increase the strength and viscoelastic properties of the PVA- borax hydrogel, cellulose nano fiber was used as reinforcing agent. By adding 2 to 6 wt% cellulose nano fibers to the PVA- borax hydrogel with the optimum composition, storage modulus and complex viscosity increased from 1.8 to 2.2 and 1.4 to 1.9 folds respectively. In the next stage of the project, the release rate of curcumin, encapsulated in pluronic F127 micelles, from hydrogel wund dress was studied. With increasing in cross links density, amount of cellulose and viscoelastic properties of hydrogels, the diffusion of the loaded drug in hydrogel structure becomes harderand the resistance of hydrogel against swelling and dissolving becomes more. As a result, the rate of drug release from hydrogel wound dress becomes slower. Finally, a significant relationship between the rate of drug release and viscoelastic properties of hydrogel was proposed
  9. Keywords:
  10. Wound Dressing ; Viscoelastic Properties ; Drug Release ; Curcumin ; Cellulose Nanofiber ; Hydrogel

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