Internalization of hydroxyapatite nanoparticles in liver cancer cells.
Hydroxyapatite (HAP) is the main inorganic component of hard tissues and shows excellent biocompatibility and osteoconductivity properties. Nanoparticles of HAP can be synthesised by the precipitation method in distilled water. The needle shaped particles are below 100 nm in size with low-crystallinity and high-surfacial activation. Recent studies showed toxic effects of HAP nanoparticles on cancer cells. Other studies focus on the application of HAP nanoparticles as drug and gene delivery system or cell marker. However, to date, the exact internalization pathway of HAP nanoparticles into cells has not been determined. When HAP nanoparticles were added to cell culture medium, the particles immediately became instable and formed agglomerates with a size of about 500-700 nm. Hence, cells seldom encounter single HAP nanoparticles in the environment of cell culture or body fluid. The TEM showed internalized HAP captured by vacuoles in the cytoplasm of the hepatocellular carcinoma cells. The invaginations in the cell membrane before nanoparticle uptake suggested endocytic pathways as internalization mechanism. This study revealed that agglomerated HAP nanoparticles were internalized by cells through the energy-dependent process of clathrin-mediated endocytosis. Depletion of intracellular potassium arrested the formation of coated pit, which inhibited the uptake of HAP.
Bauer
Ingo Werner
IW
Biomedical Materials and Engineering Research Center, Wuhan University of Technology, Luoshi Road 122#, Wuhan 430070, P.R. China. iwb78@web.de
Li
Shi-Pu
SP
Han
Ying-Chao
YC
Yuan
Lin
L
Yin
Mei-Zhen
MZ
D006528:Carcinoma, Hepatocellular / Q000378:metabolism* / Q000473:pathology; D002966:Clathrin / Q000378:metabolism; D003034:Coated Pits, Cell-Membrane / Q000187:drug effects / Q000378:metabolism; D016503:Drug Delivery Systems; D017886:Durapatite / Q000737:chemistry / Q000493:pharmacokinetics*; D006801:Humans; D007834:Lasers; D008113:Liver Neoplasms / Q000378:metabolism* / Q000473:pathology; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles; D010316:Particle Size; D011188:Potassium / Q000494:pharmacology; D012542:Scattering, Radiation; D014407:Tumor Cells, Cultured
D002966:Clathrin; D017886:Durapatite; D011188:Potassium
J Biol Chem. 1995 Aug 11;270(32):18997-9007
7642560
J Bone Joint Surg Br. 2005 Aug;87(8):1050-4
16049237
J Lipid Res. 2002 Dec;43(12):2095-104
12454271
J Biol Chem. 2004 Oct 1;279(40):41991-7
15292270
J Cell Biol. 1993 Mar;120(6):1449-59
8449988
J Mater Sci Mater Med. 2005 Mar;16(3):189-95
15744609
Biochemistry. 1996 May 7;35(18):5616-23
8639519
Biochem J. 2004 Jan 1;377(Pt 1):159-69
14505488
J Cell Biol. 1994 Nov;127(3):725-35
7962055
Biochim Biophys Acta. 2002 Feb 18;1560(1-2):25-36
11958773
Acta Orthop Scand. 1990 Aug;61(4):299-306
2402977
Microbes Infect. 2001 Jul;3(9):755-61
11489424
Pharmacol Rev. 2002 Sep;54(3):431-67
12223531
Mol Ther. 2005 May;11(5):801-10
15851018
J Gen Virol. 1998 Jun;79 ( Pt 6):1469-77
9634090
J Biotechnol. 1999 Apr 15;69(2-3):125-33
10361722
J Biomed Mater Res A. 2003 Dec 15;67(4):1228-37
14624509
Biochim Biophys Acta. 2002 Aug 15;1572(1):67-76
12204334
J Mater Sci Mater Med. 2004 Apr;15(4):413-8
15332609
J Mater Sci Mater Med. 2003 Jun;14(6):511-9
15348435
Mol Biol Cell. 1997 Jan;8(1):47-57
9017594
Gene Ther. 2001 Aug;8(15):1188-96
11509950