TY - JOUR
T1 - Aging behavior of PVA hydrogels for soft tissue applications after in vitro swelling using osmotic pressure solutions
AU - Holloway, Julianne L.
AU - Lowman, Anthony M.
AU - Palmese, Giuseppe R.
N1 - Funding Information:
The authors from Drexel University wish to acknowledge Lauren Santi and Drexel University College of Medicine for use of the cryostat and optical microscope. Additionally, Mark Vanlandingham, from the Army Research Labs in Aberdeen, MD, and Suzanne Maher, from the Hospital for Special Surgery in New York, NY, provided valuable insight over the course of this research. Funding for this project was provided by the Department of Defense through the National Defense Science and Engineering Graduate Fellowship, in addition to the U.S. Army Research Laboratory through the Army Materials Center of Excellence Program, contract W911NF-06-2-0013.
PY - 2013/2
Y1 - 2013/2
N2 - The osmotic pressure of the medium used for in vitro swelling evaluation has been shown to have a significant effect on the swelling behavior of a material. In this study, the effect of osmotic pressure during swelling on poly(vinyl alcohol) hydrogel material properties was evaluated in vitro. Osmotic pressure solutions are necessary in order to mimic the swelling pressure observed in vivo for soft tissues present in load-bearing joints. Hydrogels were characterized after swelling by mechanical testing, X-ray diffraction and optical microscopy in the hydrated state. Results indicated that hydrogel mechanical properties remained tailorable with respect to initial processing parameters; however, significant aging occurred in osmotic solution. This was observed when evaluating the mechanical properties of the hydrogels, which, before swelling, ranged from 0.04 to 0.78 MPa but, after swelling in vitro using osmotic pressure solution, ranged from 0.32 to 0.93 MPa. Significant aging was also noted when evaluating crystallinity, with the relative crystallinity ranging between 0.4 and 5.0% before swelling and between 6.5 nd 8.0% after swelling. When compared to swelling in a non-osmotic pressure solution or in phosphate-buffered saline solution, the mechanical properties were more dependent upon the final swelling content. Furthermore, increases in crystallinity were not as significant after swelling. These results highlight the importance of choosing the appropriate swelling medium for in vitro characterization based on the desired application.
AB - The osmotic pressure of the medium used for in vitro swelling evaluation has been shown to have a significant effect on the swelling behavior of a material. In this study, the effect of osmotic pressure during swelling on poly(vinyl alcohol) hydrogel material properties was evaluated in vitro. Osmotic pressure solutions are necessary in order to mimic the swelling pressure observed in vivo for soft tissues present in load-bearing joints. Hydrogels were characterized after swelling by mechanical testing, X-ray diffraction and optical microscopy in the hydrated state. Results indicated that hydrogel mechanical properties remained tailorable with respect to initial processing parameters; however, significant aging occurred in osmotic solution. This was observed when evaluating the mechanical properties of the hydrogels, which, before swelling, ranged from 0.04 to 0.78 MPa but, after swelling in vitro using osmotic pressure solution, ranged from 0.32 to 0.93 MPa. Significant aging was also noted when evaluating crystallinity, with the relative crystallinity ranging between 0.4 and 5.0% before swelling and between 6.5 nd 8.0% after swelling. When compared to swelling in a non-osmotic pressure solution or in phosphate-buffered saline solution, the mechanical properties were more dependent upon the final swelling content. Furthermore, increases in crystallinity were not as significant after swelling. These results highlight the importance of choosing the appropriate swelling medium for in vitro characterization based on the desired application.
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U2 - 10.1016/j.actbio.2012.09.018
DO - 10.1016/j.actbio.2012.09.018
M3 - Article
C2 - 23022548
AN - SCOPUS:84872072834
SN - 1742-7061
VL - 9
SP - 5013
EP - 5021
JO - Acta Biomaterialia
JF - Acta Biomaterialia
IS - 2
ER -