The Chemical Modification of Chitosan Films for Improved Hemostatic and Bioadhesive Properties.

by Yamazaki, Mai

Abstract (Summary)
Bioadhesives and hemostatic agents have been quite attractive as wound dressings. However, commercially available bioadhesives and hemostatic agents still have some limitations in terms of cytotoxicity, potential for bacterial infections, and cost performance. There is a need for developing bioresource-based adhesives that would overcome these limitations. The goal of this research is to fabricate novel bioadhesive and hemostatic agents with improved properties, provided by enhanced reactive bonding sites for bioadhesion, and enhanced blood clot forming ability for hemostatic agents. To generate a novel bioadhesive, chitosan and silk fibroin (CS/SF) blend films with dangling aldehydes were prepared by a chemical reaction between amino groups of blend films and aldehyde groups of dialdehydes. The dangling free aldehyde groups can bond to the proteinatious amino groups of tissue, which improves the bioadhesiveness. Commercial glutaraldehyde (GA) and newly synthesized 1,10-didecanal were used for the chemical modification of blend films. A dialdehyde with a long carbon chain is considered to provide better accessibility of the aldehyde group, than a shorter one, to the amino groups. Currently, very few long-chain dialdehydes are commercially available due to the synthesis difficulties. The 1, 10-didecanal and modified CS/SF blend films were characterized and the quality of bioadhesion was evaluated by tissue peeling. Novel chitosan and polyaspartic acid (CS/PAsp) polyelectrolyte complex films were successfully prepared as hemostatic agents by layer-by-layer assembly. CS is readily obtained from crustacean shell waste by a simple chemical process, whereas PAsp is easily polymerized in one pot by thermal condensation of L-Asp and subsequent hydrolysis. CS and PAsp can form a polyelectrolyte complex, which is vital for various cell cycles. In addition to the reactive chemical functional groups of each polymer, CS and PAsp potentially provide a promising substrate for antibacterial action and blood coagulation, due to the nature of CS and PAsp. The chemical, physical, and biological properties of the layered films are described.
Bibliographical Information:

Advisor:Samuel M. Hudson; Harold S. Freeman; Martin W. king; Bruce M. Novak

School:North Carolina State University

School Location:USA - North Carolina

Source Type:Master's Thesis

Keywords:fiber and polymer science


Date of Publication:04/11/2007

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