Fabrication of a new fluorescent polymeric nanoparticle containing naphthalimide and investigation on its interaction with bovine serum albumin.
A new fluorescent nanoparticle was synthesized by chemical crosslinking of polyacrylic acid using 4-aminoethanol-N-hydroxyethanyl-1,8-naphthalimide as the crosslinker. The particle possesses excellent characteristics, including low cytotoxicity, water solubility and good fluorescence properties. The interaction of the particle with bovine serum albumin was investigated by absorbance, fluorescence and circular dichroism spectroscopic methods. The interaction mechanisms, binding model and reciprocal effects on structure and fluorescence between nanoparticle and protein are discussed. The spectral data indicated that the nanoparticle could spontaneously form a reversible complex with bovine serum albumin in solution used mainly by hydrogen bonds and van der Waals forces. Fluorescence resonance energy transfer from tryptophan to naphthalimide in the complex was demonstrated and employed to determine their relative separation distance. During the interaction process, unfolding of polypeptide chains in the protein occurred but no adjustments of local polarities around the tryptophan and tyrosine residues were observed. In addition, it was found that the presence of protein induced a notable enhancement in nanoparticle fluorescence and a blue-shift in the emission maximum. These results will be useful for further applications of the developed nanoparticle in biomedical areas.
Institute of Pharmaceutical Analysis, School of Pharmaceutical Sciences, Wuhan University, Wuhan 430072, China. Electronic address: chirolab@gmail.com.
Shucai
S
Liang
Institute of Pharmaceutical Analysis, School of Pharmaceutical Sciences, Wuhan University, Wuhan 430072, China.
Yanbin
Y
Liu
Institute of Pharmaceutical Analysis, School of Pharmaceutical Sciences, Wuhan University, Wuhan 430072, China.
Jin
J
Xiang
School of Materials Science and Engineering, Wuhan Institute of Technology, Wuhan 430070, China.
Meng
M
Qin
School of Materials Science and Engineering, Wuhan Institute of Technology, Wuhan 430070, China.
Hui
H
Yu
School of Materials Science and Engineering, Wuhan Institute of Technology, Wuhan 430070, China. Electronic address: guopyan2006@163.com.
Guoping
G
Yan
D000180:Acrylic Resins / Q000138:chemical synthesis / Q000737:chemistry*; D000818:Animals; D002417:Cattle; D003432:Cross-Linking Reagents / Q000138:chemical synthesis / Q000737:chemistry*; D005453:Fluorescence; D031541:Fluorescence Resonance Energy Transfer; D015394:Molecular Structure; D053758:Nanoparticles / Q000737:chemistry*; D053644:Naphthalimides / Q000737:chemistry*; D010316:Particle Size; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D013499:Surface Properties
D000180:Acrylic Resins; D003432:Cross-Linking Reagents; D053644:Naphthalimides; D012710:Serum Albumin, Bovine; C006903:carbopol 940
Binding studies; Bovine serum albumin; Fluorescent nanoparticle; Naphthalimide; Polyacrylic acid; Spectroscopic methods