Preparation, circular dichroism induced helical conformation and optical property of chitosan acid salt complexes for biomedical applications.

The efficient procedure for preparation of chitosan acid complexes containing aspartic acid, benzilic acid and terephthalic acid moieties in isopropyl alcohol under mild condition has been demonstrated. The ionic complexation between chitosan and the acid is confirmed by FTIR and 1H NMR spectroscopy. The circular dichroism (CD) spectra of chitosan/aspartic acid complex showed negative (at lambda=312) band, chitosan/benzilic acid and chitosan/terephthalic complexes showed positive (at lambda=286 and 315 nm) band in DMSO, indicating that the polymers adopted helical (left-handed and last two right-handed) secondary structure. The inversion of the CD pattern in chitosan acid salt complexes suggests that there is a change in the chiral structure of the polymer system. Some physical properties and surface morphology were analyzed by X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetry (TG) and scanning electron microscopy (SEM). Optical properties of chitosan derivatives are evaluated by photoluminescence (PL) spectroscopy which showed red shift. The introduction of acid moieties into chitosan increases the solubility in most of the organic solvents, which opens new perspectives for the employment of chitosan-based biohybrid in biomedical applications.

[1]  J. Román,et al.  A kinetic study of the thermal degradation of chitosan and a mercaptan derivative of chitosan , 1993 .

[2]  S. Irie,et al.  Spectroscopic studies of the conformational properties of naphthoyl chitosan in dilute solutions , 2004 .

[3]  B. Nagy,et al.  Application of aspartic acid racemization to forensic odontology: post mortem designation of age at death. , 1985, Forensic science international.

[4]  A. Domard.  Determination of N-acetyl content in chitosan samples by c.d. measurements , 1987 .

[5]  K. Noguchi,et al.  Two different molecular conformations found in chitosan type II salts. , 2003, Carbohydrate research.

[6]  J. Mikroyannidis.  Synthesis and characterization of soluble, photoluminescent polyamides, polyesters and polyethers containing 9,10-di(4-biphenylyl)anthracene segments in the main chain , 2000 .

[7]  Eugene Khor,et al.  Implantable applications of chitin and chitosan. , 2003, Biomaterials.

[8]  A. Adam,et al.  Biocompatibility of thermosensitive chitosan-based hydrogels: an in vivo experimental approach to injectable biomaterials. , 2002, Biomaterials.

[9]  S. Nishimura,et al.  Chemospecific manipulations of a rigid polysaccharide: syntheses of novel chitosan derivatives with excellent solubility in common organic solvents by regioselective chemical modifications , 1991 .

[10]  Joydeep Dutta,et al.  Perspectives for chitosan based antimicrobial films in food applications , 2009 .

[11]  Yaqing Zhao,et al.  Change of handedness in cholesteric liquid crystalline phase for N-phthaloylchitosan solutions in organic solvents. , 2003, Carbohydrate research.

[12]  H. Kozłowski,et al.  Circular dichroism study , 1983 .

[13]  M. Collins,et al.  A review of the methodological aspects of aspartic acid racemization analysis for use in forensic science. , 1999, Forensic science international.

[14]  S. Irie,et al.  Preparation of benzoylchitosans and their chiroptical properties in dilute solutions , 2004 .

[15]  R. Jayakumar,et al.  Sulfated chitin and chitosan as novel biomaterials. , 2007, International journal of biological macromolecules.

[16]  J. Daub,et al.  Chemistry of porphyrin-appended cellulose strands with a helical structure: spectroscopy, electrochemistry, and in situ circular dichroism spectroelectrochemistry. , 2001, Chemistry.

[17]  S. Irie,et al.  Circular dichroism induced by the helical conformations of acylated chitosan derivatives bearing cinnamate chromophores , 2005 .

[18]  Xiaoyun Liu,et al.  Synthesis and characterization of poly(butylene succinate-co-butylene malate): a new biodegradable copolyester bearing hydroxyl pendant groups. , 2003, Biomacromolecules.

[19]  Z. Xiufang,et al.  Studies on nerve cell affinity of chitosan-derived materials. , 2000, Journal of biomedical materials research.

[20]  R. Reis,et al.  GRAFT COPOLYMERIZED CHITOSAN-PRESENT STATUS AND APPLICATIONS , 2005 .

[21]  W. Prinyawiwatkul,et al.  Applications of chitosan for improvement of quality and shelf life of foods: a review. , 2007, Journal of food science.

[22]  J. Millership,et al.  Commonly used chiral drugs: a survey. , 1993, Chirality.

[23]  M. Morimoto,et al.  Preparation and characterization of water-soluble chitin and chitosan derivatives , 1998 .

[24]  T. Takei,et al.  Release behaviour of 5-fluorouracil from chitosan-gel microspheres immobilizing 5-fluorouracil derivative coated with polysaccharides and their cell specific recognition. , 1993, Journal of microencapsulation.

[25]  T. Ungár.  Characterization of nanocrystalline materials by X-ray line profile analysis , 2007 .

[26]  A Pawlak,et al.  Thermogravimetric and FTIR studies of chitosan blends , 2003 .

[27]  B. Waldeck.  Biological significance of the enantiomeric purity of drugs. , 1993, Chirality.

[28]  Meng Yang,et al.  Ionic interactions between sulfuric acid and chitosan membranes , 2008 .

[29]  M. Fox,et al.  Photophysical characterization of dilute solutions and ordered thin films of alkyl-substituted polyfluorenes , 1999 .

[30]  D. Liaw,et al.  Novel Organosoluble Poly(pyridine−imide) with Pendent Pyrene Group: Synthesis, Thermal, Optical, Electrochemical, Electrochromic, and Protonation Characterization , 2007 .

[31]  É. Cavalheiro,et al.  Synthesis and characterization of Schiff bases from chitosan and salicylaldehyde derivatives , 2005 .

[32]  A. Domard,et al.  Chitosan carboxylic acid salts in solution and in the solid state , 1994 .

[33]  K. Ogawa,et al.  X-Ray diffraction study of sulfuric, nitric, and halogen acid salts of chitosan , 1987 .