[Surface modification and DNA-binding assessment of nano-hydroxyapatite].
OBJECTIVE
To evaluate the impact of surface modification on the DNA-binding ability of nano-hydroxyapatite (nHA).


METHODS
Chemical co-precipitation-hydrothermal synthesis was utilized to prepare the nHA particles, and polyethylenimine (PEI) was used for surface modification of the nHA. Transmission electron microscopic (TEM) observation and zeta potential detection of the nHA were carried out before and after surface modification. The abilities of the nanoparticles, at different pH values and different concentrations, for DNA-binding and DNA protection against nuclease digestion were assessed before and after surface modification by electrophoresis.


RESULTS
TEM observation showed a short rod-like morphology of PEI-modified nHA with uniform particle size and good dispersion; the nHA without the modification tended to aggregate with poor dispersion. With a positive zeta potential, the PEI-modified nHA showed an obviously enhanced ability of DNA binding at different pH values and concentrations, with strong capacity to protect the DNA against Dnase I digestion. At the concentration of 250 µg/ml and a pH value of 7.0, the nHA-PEI showed an optimal efficiency of DNA-binding and DNA protection.


CONCLUSIONS
nHA with surface modification by PEI can serve as an effective vector for DNA binding and transfer.
Department of Otolaryngology, Head and Neck Surgery, Center for Experimental Medicine Research, Third Xiangya Hospital of Central South University, Changsha 410013, China. wuxh-2008@163.com
Xiong-hui
XH
Wu
Hong
H
Sun
Xiao-wei
XW
Xing
Li-hua
LH
Huang
Su-ping
SP
Huang
D020816:Amino Acid Motifs; D004247:DNA / Q000737:chemistry*; D017886:Durapatite / Q000737:chemistry*; D018014:Gene Transfer Techniques; D005822:Genetic Vectors; D053758:Nanoparticles / Q000737:chemistry*; D011094:Polyethyleneimine / Q000737:chemistry
D011094:Polyethyleneimine; D004247:DNA; D017886:Durapatite