@inproceedings{01JR7QPSD2BM87ZC52XDHR9WP9,
  abstract     = {{Osseous-cyst-like lesions in equine patients pose a significant challenge and existing therapies do
not show satisfactory results. For this reason, the present in vitro study evaluates the osteogenic
regenerative potential of gelatin-based hydrogels combined with equine bone marrow-derived
mesenchymal stem cells (BM-MSCs). First, two hydrogels were synthesized using both
methacrylamide (-MA) and norbornene functionalization (-NB), resulting in Gel-MA- NB with (1) a
degree of substitution (DS) of 51 and 28%, respectively, and (2) Gel-MA-NB with 61 and 11%
(determined using 1H-NMR spectroscopy). Both hydrogels were further processed using three
different methods: (a) Pre-crosslinked MA: -MA groups were crosslinked using Lithium(2,4,6-
trimethylbenzoyl)phenylphosphinat (LAP) and subsequently ground; (b) Pre-Crosslinked MA-NB: -
MA and -NB groups were simultaneously crosslinked using LAP and PEG2SH, after which the
material was ground; (c) Post-crosslinked NB: using the pre-crosslinked MA powder, -NB groups
were crosslinked in a second step using LAP and PEG2SH. To characterize the hydrogels, rheology
measurements were performed, resulting in a storage modulus between 1.99 +/- 0.01 and 8.6 +/-
0.21kPa. Regarding processing, the highest storage modulus was observed for the post-crosslinked
-NB hydrogels and the lowest for the pre-crosslinked -MA hydrogels. Regarding DS, the higher the -
MA substitution, the higher the storage modulus of the pre-crosslinked MA gels; the higher the -NB
substitution, the higher the storage modulus of the pre- MA-NB and post-crosslinked NB gels.
During injectability testing with a 20G needle, an average force ranging from 12.69 to 30.839 N was
required. Only the Gel-MA51-NB28 with pre-crosslinked MA-NB was too stiff and could not be
injected through the 20G needle. For the biological evaluation, the pre-crosslinked MA and MA-NB
gels (10% w/v) were mixed with a solution of BM-MSCs (passage 5-7) in DMEM at a concentration
of 2x106 cells/mL. The post-crosslinked NB hydrogels were first dissolved in DMEM, after which LAP,
PEG2SH and BM-MSCs were added and exposed to UVa-light for 10min. After gelation, the hydrogel
containing BM-MSCs was incubated in expansion medium for one day and subsequently
differentiated in osteogenic medium. At day 7, 14 and 21, viability and proliferation was assessed
using a MTT assay. Overall, the absorbance tended to decrease during the culture period, which
might be explained by increasing osteogenic differentiation. Viability of the BM-MSCs was highest
in the pre-crosslinked MA gel-MA61- NB11. Additionally, alkaline phosphatase activity (ALP) for
early and calcium matrix- production (Ca2+) for late osteogenic differentiation was evaluated. ALP
activity should first increase and over time decrease to allow Ca2+ production, which was indeed
observed in pre- crosslinked MA gel-MA61-NB11. Furthermore, in both pre-crosslinked MA
hydrogels, Ca2+ already increased between day 7 and 14, while the Ca2+ in the pre-crosslinked MA-
NB hydrogels only increased after day 14 and did not reach the same level after 21 days. The post-
crosslinked NB hydrogels showed no Ca2+ production. The DS of the MA and NB groups did not
appear to have a significant impact on the Ca2+ results. In conclusion, this study provides a step
forward in the development of a bone-cyst filling material}},
  author       = {{Mokry, Anna and Meeremans, Marguerite and Pien, Nele and Van Damme, Lana and Van Vlierberghe, Sandra and De Schauwer, Catharina}},
  booktitle    = {{Tissue Engineering, 11th Belgian symposium, Abstracts}},
  language     = {{eng}},
  location     = {{Leuven, Belgium}},
  title        = {{Injectable hydrogels combined with MSCs to treat bone cysts in horses}},
  url          = {{https://www.bste.be/bste-2024-event#abstracts}},
  year         = {{2024}},
}