title: Synthesis and antimicrobial activity of some novel cross-linked chitosan hydrogels.
abstract: Four novel hydrogels based on chitosan were synthesized via a cross-linking reaction of chitosan with different concentrations of oxalyl bis 4-(2,5-dioxo-2H-pyrrol- 1(5H)-yl)benzamide. Their structures were confirmed by fourier transform infrared X-ray (FTIR), scanning electron microscopy (SEM) and X-ray diffraction. The antimicrobial activities of the hydrogels against two crop-threatening pathogenic fungi namely: Aspergillus fumigatus (A. fumigatus, RCMBA 06002), and Aspergillus niger (A. niger, RCMBA 06106), and five bacterial species namely: Bacillis subtilis (B. subtilis, RCMBA 6005), Staphylococcus aureus (S. aureus, RCMBA 2004), Streptococcus pneumoniae (S. pneumonia, RCMB 000101) as Gram positive bacteria, and Salmonella typhimurium (S. typhimurium, RCMB 000104), and Escherichia coli (E. coli, RCMBA 5003) as Gram negative bacteria have been investigated. The prepared hydrogels showed much higher antimicrobial activities than that of the parent chitosan. The hydrogels were more potent in case of Gram-positive bacteria than Gram-negative bacteria. Increasing the degree of cross-linking in the hydrogels resulted in a weaker antimicrobial activity.
authors.affiliation: Department of Chemistry, Faculty of Science, Cairo University, Giza 12613, Egypt.
authors.forename: Nadia Ahmed
authors.initials: NA
authors.lastname: Mohamed
authors.affiliation: Department of Chemistry, Faculty of Science, Cairo University, Giza 12613, Egypt.
authors.forename: Mona Mohamed
authors.initials: MM
authors.lastname: Fahmy
mesh_terms: D000890:Anti-Infective Agents / Q000138:chemical synthesis* / Q000494:pharmacology*; D001232:Aspergillus fumigatus / Q000187:drug effects; D001234:Aspergillus niger / Q000187:drug effects; D001412:Bacillus subtilis / Q000187:drug effects; D001549:Benzamides / Q000737:chemistry; D048271:Chitosan / Q000737:chemistry / Q000494:pharmacology*; D004926:Escherichia coli / Q000187:drug effects; D020100:Hydrogels / Q000138:chemical synthesis / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D012486:Salmonella typhimurium / Q000187:drug effects; D017550:Spectroscopy, Fourier Transform Infrared; D013211:Staphylococcus aureus / Q000187:drug effects; D013296:Streptococcus pneumoniae / Q000187:drug effects
chemical_list: D000890:Anti-Infective Agents; D001549:Benzamides; D020100:Hydrogels; C037689:benzamide; D048271:Chitosan
keywords: antimicrobial activity; chemical cross-linking; chitosan; hydrogels