Article: Lynch, B; Crawford, K; Baruti, O; Abdulahad, A; Webster, M; Puetzer, J; Ryu, C; Bonassar, LJ; Mendenhall, J; “The effect of Hypoxia on Thermosensitive Poly(N-vinylcaprolactam) Hydrogels with Tunable Mechanical Integrity for Cartilage Tissue Engineering”, Journal of Biomedical Materials Research Part B-Applied Biomaterials, 105 (7):1863-1873
Abstract: Cartilage repair presents a daunting challenge in tissue engineering applications due to the low oxygen conditions (hypoxia) affiliated in diseased states. Hence, the use of biomaterial scaffolds with unique variability is imperative to treat diseased or damaged cartilage.
Thermosensitive hydrogels show promise as injectable materials that can be used as tissue scaffolds for cartilage tissue regeneration. However, uses in clinical applications are limited to due mechanical stability and therapeutic efficacy to treat diseased tissue. In this study, several composite hydrogels containing poly(N-vinylcaprolactam) (PVCL) and methacrylated hyaluronic acid (meHA) were prepared using free radical polymerization to produce PVCL-graft-HA (PVCL-g-HA) and characterized using Fourier transform infrared spectroscopy, nuclear magnetic resonance, and scanning electron microscopy. Lower critical solution temperatures and gelation temperatures were confirmed in the range of 33-34 degrees C and 41-45 degrees C, respectively. Using dynamic sheer rheology, the temperature dependence of elastic (G) and viscous (G) modulus between 25 degrees C and 45 degrees C, revealed that PVCL-g-HA hydrogels at 5% (w/v) concentration exhibited the moduli of 7Pa (G) to 4Pa (G). After 10days at 1% oxygen, collagen production on PVCL-g-HA hydrogels was 153 +/- 25g/mg (20%) and 106 +/- 18g/mg showing a 10-fold increase compared to meHA controls. These studies show promise in PVCL-g-HA hydrogels for the treatment of diseased or damaged articular cartilage. (c) 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1863-1873, 2017.
Funding Acknowledgement: Rensselaer Polytechnic Institute Nanoscale Science and Engineering Center for Directed Assembly of Nanostructures (NSF Partnerships in Undergraduate Institutions) [A12024-01/DMR-0642573]; Martin Luther King, Jr. Visiting Professorship at Massachusetts Institute of Technology; Institute of Solider Nanotechnology at MIT; NSF [DMR-1120296]; Cornell University Louis Stokes Alliance for Minority Participation (LSAMP), NSF [06-552]
Funding Text: The authors would like to acknowledge Rensselaer Polytechnic Institute Nanoscale Science and Engineering Center for Directed Assembly of Nanostructures (NSF Partnerships in Undergraduate Institutions: A12024-01/DMR-0642573) and the Martin Luther King, Jr. Visiting Professorship at Massachusetts Institute of Technology and the Institute of Solider Nanotechnology at MIT. A special thanks to Dr. Jason Suarez at the Malvern Instruments Analysis Lab for the analysis of PVCL using Viscotek Triple detector system. We also would like to thank the Cornell Center for Materials Research funded by NSF for the SEM images (DMR-1120296) and the Cornell University Louis Stokes Alliance for Minority Participation (LSAMP), NSF supported program under Grant No. 06-552.