Fig. 2
Characterization and PGE2 release kinetics of the PGE2 matrix. A Quantification of the level of PGE2 before and after crosslinking onto collagen using the ELISA assay. Pure collagen served as a control. Data are expressed as mean ± SD; *P < 0.05 versus control; The experiments were carried out in triplicate. Evaluation of the rheological profile of the PGE2 matrix with changes in temperature (B), strain sweep (C), and frequency sweep (D). G’ storage modulus and G’ loss modulus. E Complex viscosity vs. frequency plots for the PGE2 matrix. F A scanning electron micrograph (SEM) image of the lyophilized PGE2 matrix reveals the morphological structure. The bar represents 20 μm. G In vitro release profile of PGE2 from the PGE2 matrix determined by the ELISA assay. The PGE2 group (free PGE2 mixed with collagen) was tested as a control. Data are expressed as mean ± SD; the experiments were carried out in triplicate. H For in vivo PGE2 release analysis, the PGE2 matrix was injected into the hindlimb model of ischemic muscle. The muscle samples were then prepared and homogenized at different specific time points to assess the released PGE2 using an ELISA assay. Hindlimb ischemia mice injected with collagen served as a control group to measure signal change when injured. The Sham group served as a blank to reflect the baseline level of PGE2. Data are expressed as mean ± SD; n = 3, *P < 0.05 versus PGE2 group; #P < 0.05 versus control