Chitosan rod reinforced by self-crosslinking through thermal treatment

Abstract

Chitosan (CS) rods were reinforced at high temperatures to form network structure by self-crosslinking of amino groups. Properties of treated CS rods were studied by FTIR spectroscopy, intrinsic viscosity measurement, mechanical properties testing and water absorption measurement. The FTIR spectra indicated that the CS configuration was transformed from ?-CS for untreated CS rods to ?-CS for thermally treated CS rods. Meanwhile, the crosslinking also occurred between amino groups of CS. Due to the increase in the crosslinking degree, the intrinsic viscosity increased with the rising of temperature. It was found that the network structure enhanced the bending strength of CS rods, which reached 154.8 MPa when CS rods were treated at 140°C for 2 h. Thermal treatment also reduced the water absorption of CS rods. Due to the improved mechanical properties, thermally treated CS rods could be used as a novel device for internal fixation of bone fracture.

References

1. Di Martino A Sittinger M Risbud M V A versatile biopolymer for orthopaedic tissue-engineeringBiomaterials 2005 26(30)59835990. doi:10.1016/j.biomaterials.2005.03.016
2. Kim S B Kim Y J Yoon T R et al.The characteristics of a hydroxyapatite-chitosan-PMMAbone cementBiomaterials 2004 25(26)57155723. doi:10.1016/j.biomaterials.2004.01.022
3. Zhu Y Wang X H Cui F Z et al.In vitro cytocompatibilityand osteoinduction of phosphorylated chitosan with osteoblastsJournal of Bioactive and Compatible Polymers 2003 18(5)375390. doi:10.1177/0883911503039020
4. Leroux L Hatim Z Freche M et al.Effects of various adjuvants (lactic acid, glycerol,and chitosan) on the injectability of a calcium phosphate cementBone 1999 25(2)3134. doi:10.1016/S8756‐3282(99)00130‐1
5. Hu Q L Qian X Z Li B Q et al.Studies on chitosan rods prepared by in situ precipitation methodChemical Journal of Chinese Universities 2003 24(3)528531 (in Chinese)
6. Lim L Y Khor E Ling C E Effects of dry heat and saturated steam on the physicalproperties of chitosanJournal of BiomedicalMaterials Research 1999 48(2)111116. doi:10.1002/(SICI)1097‐4636(1999)48:2<111::AID‐JBM3>3.0.CO;2‐W
7. Yu J H Du Y M Zheng H Studies on the preparation, characterization and propertiesof nylon 1010-chitosan blend filmsPolymerMaterials Science & Engineering 2001 17(5)116120 (in Chinese)
8. Li B Q Hu Q L Qian X Z et al.Bioabsorbable chitosan/hydroxyapatite compositerod prepared by in-situ precipitationfor internal fixation of bone fractureActaPolymerica Sinica 2002 (6)828833 (in Chinese)
9. Hu Q L Li B Q Wang M et al.Preparation and characterization of biodegradablechitosan/hydroxyapatite nanocomposite rods via in-situ hybridization: a potential material as internalfixation of bone fractureBiomaterials 2004 25(5)779785. doi:10.1016/S0142‐9612(03)00582‐9
10. Jiang T D ChitinBeijingChemicalIndustry Press 2003 3340 (in Chinese)
11. Hu Q L Lei Y Zhang Z M et al.Surface biomimetic waterproof modification of chitosanrodChemical Research in Chinese Universities 2005 26(6)11621165 (in Chinese)