Figure 1.
The chemical structure of the maleimide modified HA (MAHA) and encapsulation of hMSCs in MAHA hydrogels.
(A) Modification of hyaluronic acid to yield maleimide modified HA (MAHA). (B) Encapsulation of hMSCs in MAHA hydrogels using either MMP-cleavable peptides or MMP-insensitive DTT as crosslinkers.
Table 1.
Sequences of primers and probes used for Real-Time PCR. Sequences related to gene type X collagen and MMP13 are proprietary to Applied Biosystems Inc. and not disclosed.
Figure 2.
The physical properties of the hydrogels formed using different crosslinkers.
(A) Weight degree of swelling (the ratio between the swollen wet weight and dry weight) and (B) equilibrium modulus of acellular hydrogels crosslinked using either MMP-cleavable peptides or MMP-insensitive DTT after 24 hours of equilibration in phosphate buffered saline.
Figure 3.
The cell viability staining on day 1 (A) and 14 (B) of the culture.
Bar = 100 µm.
Figure 4.
The gene expression of type II collagen, aggrecan, type X collagen and MMP13 in fold changes on day 7, 14 or 28 of the culture normalized to pre-differentiated cells.
*p<0.05 vs. MMP group (n = 4).
Figure 5.
The analysis of the cartilaginous matrix contents of the hMSC-seeded hydrogels.
GAG and collagen content (normalized to the DNA content) of hMSC-laden HA hydrogels (A) and immunohistochemistry staining of the hydrogel constructs against chondroitin sulfate, type II and I collagen after 28 days of culture (B), Bar = 50 µm, *p<0.05 vs. MMP group (n = 4).
Figure 6.
The evaluation of the hypertrophic calcification of the hydrogels.
Calcium content of the hMSC-laden hydrogels normalized to wet weight (w.t.) and dry weight (d.w) (A); and Von Kossa staining of the histological sections of the hydrogels after 28 days of culture, bar = 500 µm, *p<0.05 vs. MMP group (n = 4).