title: Quaternized chitosan particles as ion exchange supports for label-free DNA detection using PNA probe and MALDI-TOF mass spectrometry.
abstract: Quaternized chitosan particles are introduced as anion-exchanged captures to be used with a conformationally constrained pyrrolidinyl peptide nucleic acid (acpcPNA) and MALDI-TOF mass spectrometry for DNA sequence analysis. Methylated chitosan (MC) and methylated N-benzyl chitosan (MBzC) particles were obtained by heterogeneous chemical modification of ionically cross-linked chitosan particles via direct methylation and reductive benzylation/methylation, respectively. N,N,N-trimethylchitosan (TMC) and N-[(2-hydroxyl-3-trimethylammonium)propyl]chitosan chloride (HTACC) particles were prepared by ionic cross-linking of quaternized chitosan derivatives, homogeneously modified from chitosan, namely TMC and HTACC, respectively. The particles formed had a size in a sub-micrometer range and possessed positive charge. Investigation by MALDI-TOF mass spectrometry suggested that some quaternized particles in combination with acpcPNA were capable of detecting a single mismatched base out of 9-14 base DNA sequences. Potential application of this technique for the detection of wild-type and mutant K-ras DNA, a gene that mutation is associated with certain cancers, has also been demonstrated.
authors.affiliation: Program in Petrochemistry and Polymer Science, Faculty of Science, Chulalongkorn University, Phayathai Road, Pathumwan, Bangkok 10330, Thailand; Center of Excellence on Petrochemical and Materials Technology, Chulalongkorn University, Phayathai Road, Pathumwan, Bangkok 10330, Thailand.
authors.forename: Jittima
authors.initials: J
authors.lastname: Meebungpraw
authors.affiliation: Program in Petrochemistry, Faculty of Science, Chulalongkorn University, Phayathai Road, Pathumwan, Bangkok 10330, Thailand.
authors.forename: Oraphan
authors.initials: O
authors.lastname: Wiarachai
authors.affiliation: Organic Synthesis Research Unit, Department of Chemistry, Chulalongkorn University, Phayathai Road, Pathumwan, Bangkok 10330, Thailand.
authors.forename: Tirayut
authors.initials: T
authors.lastname: Vilaivan
authors.affiliation: Department of Imaging and Printing Technology, Faculty of Science, Chulalongkorn University, Phayathai Road, Pathumwan, Bangkok 10330, Thailand.
authors.forename: Suda
authors.initials: S
authors.lastname: Kiatkamjornwong
authors.affiliation: Organic Synthesis Research Unit, Department of Chemistry, Chulalongkorn University, Phayathai Road, Pathumwan, Bangkok 10330, Thailand. Electronic address: vipavee.p@chula.ac.th.
authors.forename: Voravee P
authors.initials: VP
authors.lastname: Hoven
mesh_terms: D000327:Adsorption; D048271:Chitosan / Q000138:chemical synthesis / Q000737:chemistry*; D004247:DNA / Q000032:analysis*; D007474:Ion Exchange; D020135:Peptide Nucleic Acids / Q000737:chemistry*; D066244:Proton Magnetic Resonance Spectroscopy; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D013194:Staining and Labeling
chemical_list: C118071:N-trimethyl chitosan chloride; D020135:Peptide Nucleic Acids; D004247:DNA; D048271:Chitosan
keywords: Chitosan; DNA sequence analysis; MALDI-TOF mass spectrometry; Pyrrolidinyl peptide nucleic acid; Quaternary ammonium group