The effects of fixed electrical charge on chondrocyte behavior.
In this study we have compared the effects of negative and positive fixed charges on chondrocyte behavior in vitro. Electrical charges have been incorporated into oligo(poly(ethylene glycol) fumarate) (OPF) using small charged monomers such as sodium methacrylate (SMA) and (2-(methacryloyloxy) ethyl)-trimethyl ammonium chloride (MAETAC) to produce negatively and positively charged hydrogels, respectively. The physical and electrical properties of the hydrogels were characterized by measuring and calculating the swelling ratio and zeta potential, respectively. Our results revealed that the properties of these OPF modified hydrogels varied according to the concentration of charged monomers. Zeta potential measurements demonstrated that the electrical properties of the OPF hydrogel surfaces changed on incorporation of SMA and MAETAC and that these changes in electrical properties were dose-dependent. Attenuated total reflectance Fourier transform infrared spectroscopy was used to determine the hydrogel surface composition. To assess the effects of surface properties on chondrocyte behavior primary chondrocytes isolated from rabbit ears were seeded as a monolayer on top of the hydrogels. We demonstrated that the cells remained viable over 7 days and began to proliferate while seeded on top of the hydrogels. Collagen type II staining was positive in all samples, however, the staining intensity was higher on negatively charged hydrogels. Similarly, glycosaminoglycan production was significantly higher on negatively charged hydrogels compared with a neutral hydrogel. Reverse transcriptase polymerase chain reaction showed up-regulation of collagen type II and down-regulation of collagen type I on the negatively charged hydrogels. These findings indicate that charge plays an important role in establishing an appropriate environment for chondrocytes and, hence, in the engineering of cartilage. Thus, further investigations into charged hydrogels for cartilage tissue engineering is merited.
Department of Orthopedic Surgery, Mayo Clinic College of Medicine, Rochester, MN 55905, USA.
Mahrokh
M
Dadsetan
Matthias
M
Pumberger
Michelle E
ME
Casper
Kristin
K
Shogren
Melissa
M
Giuliani
Terry
T
Ruesink
Theresa E
TE
Hefferan
Bradford L
BL
Currier
Michael J
MJ
Yaszemski
D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects; D002452:Cell Count; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D019902:Chondrocytes / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D024043:Collagen Type II / Q000378:metabolism; D019245:Compressive Strength / Q000187:drug effects; D003432:Cross-Linking Reagents / Q000494:pharmacology; D004553:Electric Conductivity; D004560:Electricity; D005455:Fluorescent Antibody Technique; D006025:Glycosaminoglycans / Q000378:metabolism; D020100:Hydrogels / Q000737:chemistry / Q000494:pharmacology; D055595:Mechanical Phenomena / Q000187:drug effects; D016133:Polymerase Chain Reaction; D011817:Rabbits; D017550:Spectroscopy, Fourier Transform Infrared; D055672:Static Electricity
D024043:Collagen Type II; D003432:Cross-Linking Reagents; D006025:Glycosaminoglycans; D020100:Hydrogels
N Engl J Med. 1994 Oct 6;331(14):889-95
8078550
J Biomech. 2000 Dec;33(12):1663-73
11006391
Drug Discov Today. 2002 May 15;7(10):569-79
12047857
J Biomed Mater Res. 2002 Mar 5;59(3):429-37
11774300
Matrix Biol. 2010 Jan;29(1):51-62
19720146
Injury. 2008 Apr;39 Suppl 1:S40-9
18313471
J Bone Joint Surg Am. 1980 Jan;62(1):79-89
7351420
Ann Biomed Eng. 2004 Mar;32(3):407-17
15095815
Arthritis Rheum. 1993 Aug;36(8):1103-10
8343186
Biomed Sci Instrum. 1999;35:309-14
11143369
Macromol Biosci. 2009 Apr 8;9(4):307-16
19031389
Biomacromolecules. 2001 Spring;2(1):255-61
11749181
Ann Biomed Eng. 2003 Nov;31(10):1162-70
14649490
Biorheology. 2002;39(1-2):39-45
12082265
Spine (Phila Pa 1976). 2002 Nov 1;27(21):2390-5
12438989
Methods Enzymol. 1979;58:560-4
423791
Arthritis Res Ther. 2007;9(5):109
18021426
Osteoarthritis Cartilage. 1994 Jun;2(2):91-101
11548233
Science. 1972 Dec 1;178(4064):982-3
5084665
Biomaterials. 2009 Aug;30(23-24):3874-81
19427689
Acta Biomater. 2005 Mar;1(2):243-52
16701801
Biomacromolecules. 2007 May;8(5):1702-9
17419584
Biomaterials. 2001 Mar;22(6):619-26
11219727