Presenter: FengChien Hsu - PowerPoint PPT Presentation

Title: Presenter: FengChien Hsu


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High strength of poly(acrylic acid)-chitosan-sili
ca hydrogel composites

• Presenter Feng-Chien Hsu
• Adviser Professor Hong-Ru Lin
• Date 2009/11/21

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Introduction

• Joint pain is a major cause of disability in
  middle-aged and older people. Joints cartilage
  due to primary osteoarthritis or from trauma
  causing loss of cartilage.
• Chitosan is one of the most abundant biomass
  sources in the world. Its chemical structure is
  analogous with diverse glycosaminoglycans found
  in articular cartilage.

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• Nano-sized silica particles were recently fused
  onto ceramic whiskers and used as fillers to
  reinforce dental resin to extend their use to
  large stress-bearing restorations.
• Most of hydrogels derived from either natural or
  synthetic sources suffer from lack of mechanical
  strength. In this study, high strength
  poly(acrylic acid)-chitosan-silica(PAA-Ch-Si)
  hydrogels were prepared by UV polymerization for
  cartilage repair.

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Materials
poly(acrylic acid)-chitosan-silica(PAA-Ch-Si)
hydrogels

• Acrylic acid (AAc)
• Chitosan
• Silica
• Ammonium peroxodisulfate (APS)
• N,N-methylenebisacrylamide (NMBA)
• Glutaraldehyde (GA)

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Preparation
Acrylic acid
APS?NMBA and GA
Distilled water
Chitosan
Stirred until complete dissolved
Injected to mold
Exposed to UV-light
Hydrogel
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Results and discussion
Table.1 Mechanical properties of PAA, PAA-Ch,
PAASi and PAA-Ch-Si hydrogels
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Fig.1 Scanning electron microscope of PAA,
PAA-Ch, PAA-Si and PAA-Ch-Si hydrogels
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Conclusion

• The PAA-Ch-Si hydrogel had highest mechanical
  strength(42 MPa) among the others. Its elastic
  modulus, toughness and cross-link density were
  all higher than other hydrogels.
• The SEM image shows that pores were distributed
  inside the PAA-Ch-Si hydrogel, which is expected
  to absorb body fluid once implanted.

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References
1 Junping Zhang, Qin Wang, Aiqin Wang,
Synthesisand characterization of
chitosan-g-poly(acrylic acid)/attapulgite
superabsorbent composites, Carbohydrate Polymers,
367374 (2007) 68. 2 Kyung Min Park, Sang Young
Lee, Yoon Ki Joung, Jae Sik Na, Myung Chul Lee,
Ki Dong Park , Thermosensitive chitosanPluronic
hydrogel as an injectable cell delivery carrier
for cartilage regeneration, Acta Biomaterialia,
19561965 (2009) 5. 3 Hockin H.K. Xu, Douglas
T. Smith, Carl G. Simon, Strong and bioactive
composites containing nanosilica-fused whiskers
for bone repair, Biomaterials, 46154626 (2004)
25. 4 Xiaomei Shi, Shimei Xu, Jiantao Lin, Shun
Feng, Jide Wang Synthesis of SiO2-polyacrylic
acid hybrid hydrogel with high mechanical
properties and salt tolerance using sodium
silicate precursor through solgel process,
Materials Letters,527529 (2009) 63. 5 Jian
Ping Gong, Yoshinori Katsuyama, Takayuki
Kurokawa, Yoshihito Osada Double-network
hydrogels with extremely high mechanical
strength, Advanced Materials, 1155-1158(2003)
14. 6 C. Schiraldi, A. DAgostino, A. Oliva, F.
Flamma, A. De Rosa, A. Apicella, R. Aversa and M.
De Rosa, Biomaterials, 3645 (2004) 25.
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