Fabrication and Chracatization of Novel Electrospun Chitosan Fibers Reinforced with Bacterial Cellulose and Nanodiamond for Wound Dressing Applications

Ostadhossein, Fatemeh | 2014

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  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 45915 (07)
  4. University: Sharif University of Technology
  5. Department: Materials Science and Engineering
  6. Advisor(s): Simchi, Abdolreza
  7. Abstract:
  8. Chronic wounds are among the serious injuries which have called the attention of scientists to invest in an effort to fabricate temporary skin grafts and wound dressing materials. One of the widely acceptable solutions to this obstacle is to design a bioactive scaffold capable of regenerating tissue as well as delivering active agents to the site specific area. To this end, natural biopolymers are considered as suitable candidates to be employed in regenerative medicine due to their excellent biocompatibility. In addition, nanoparticles possess special properties such as the ability in sequestering the drug release which make them promising candidates in the fabrication of the multifunctional tissue engineering materials. Electrospining has lately been acknowledge as a suitable method in wound dressing fabrication since it is capable of producing nanofibers with high specific surface area and interconnected porosity.In the present study, Nanodiamond (ND) embedded in the polysaccharide based film of Chitosan (CS) and Bacterial Cellulose (BC) has been fabricated through facile and scalable process of casting the aquatic suspension. The physical and chemical properties of the films such as the dispersion of the nanoparticles in the matrix, thermal stability, optical clarity and chemical interaction between the components have been investigated through multiple characterization methods. Furthermore, to assess the suitability of the prepared scaffold for skin regeneration, samples were freeze dried to obtain a porous medium with interconnected porosity to act as extracellular matrix for cell attachment and proliferation. Results indicate that ND particles have become well dispersed in the matrix with occasional agglomeration in high (>2 wt%) ND loadings. IR spectroscopy reveals the high miscibility of BC and CS and hydrogen bond formation between ND and polymer matrix. MTT assay results show that the scaffold does not have any cytotoxic effects on L929 fibroblast cell line. FE- SEM imaging of the cells demonstrates the cell adherence to the basement through multiple lamellapodia as well as cell- cell interaction. Overall, the results suggest that BC/ CS/ ND may potentially be advantageous as a flexible nanostructure platform for a variety of biomedical applications including tissue engineering scaffolds. The initial assessments have well corroborated the lack of cytoxicity due to ND addition. Therefore, we took a step to successfully fabricate electrospun CS nanofibers reinforced with BC and ND. The fibers were 80- 180 nm in diameter and were highly porous in structure. Furthermore, ND addition up to 1 wt% significantly reduced the fiber diameter as compared with pristine BC/ CS samples (almost half fold decrease). Besides, MTT assay did not show any toxicity effect after 24h and 72h of incubation. In summary, the highly porous and flexible nanocomposite can serve as a promising candidate for wound dressing applications
  9. Keywords:
  10. Chitosan ; Diamond Nanoparticle ; Electrospinning ; Freeze Drying Method ; Wound Healing ; Tissue Engineering ; Bacterial Cellulose ; Wound Dressing

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