Sol-gel transition temperature-controllable Pluronic F127/F68 mixtures including mildly crosslinked alginate and nonsteroidal anti-inflammatory drug (ibuprofen) were prepared to evaluate their potential as tissue adhesion barrier gels. The sol-gel transition temperatures of the Pluronic mixtures could be controlled by adjusting F127/F68 ratio and polymer concentration. The mildly crosslinked alginate with still flow property provided the residence stability of Pluronic mixture gels in the body. Ibuprofen was loaded in Pluronic mixtures to reduce inflammatory response in the body and, thus, to prevent tissue adhesion. The gelation temperatures of the Pluronic mixtures were not affected by the alginate but lowered by the addition of ibuprofen. The in vitro drug release behavior and in vivo peritoneal tissue adhesion of the Pluronic mixtures with the sol-gel transition just below body temperatures were investigated. The drug release behavior from the ibuprofen (1 wt%)-loaded Pluronic mixture gels at 37 degrees C was examined using a membrane-less dissolution model. The drug in the mixture gels was released continuously up to about 45-65% of the total loading amount during the first 7 days. For in vivo evaluation of tissue anti-adhesion potential, the Pluronic mixtures with/without drug were coated on the peritoneal wall defects of rats and their tissue adhesion extents and tissue reactions (inflammatory response, granulation tissue formation, and toxicity in organs) were compared. It was observed that ibuprofen has a positive effect for the peritoneal tissue anti-adhesion. The Pluronic F127/F68/alginate/ibuprofen mixture gel (25 wt% of F127/F68 [7/3], 1 wt% ibuprofen) was highly effective for the prevention of peritoneal tissue adhesion and showed a relatively low inflammatory response and non-toxicity, and thus can be a good candidate material as a coatable or injectable tissue adhesion barrier gel.

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OBJECTIVE: To evaluate the muscle healing effect of passive mobilization exercises after a laceration injury. DESIGN: Randomized‐controlled trial. SETTING: Basic science laboratory. ANIMALS: Male Sprague–Dawley rats (N=36), age ranging from 8 to 10 weeks and weight ranging from 300 to 400 g. INTERVENTION: The bilateral gastrocnemius muscles were lacerated. The left‐leg muscles were used as the study groups and the right side was used as the control (lacerated muscles without any treatment, n=8). In the exercise group (n=24), passive mobilization exercise (15 min/day) was performed for 5 days starting from different time points (2, 7, and 14 days postlaceration). The decorin group (n=8) was injected with decorin (50 μg at 14 days postlaceration), which is a well‐known antifibrotic agent. Four animals were used as the normal controls, in which only the muscle strength was evaluated. All the animals were killed 4 weeks after the laceration. MAIN OUTCOME MEASURES: The histologic characterization of muscle regeneration (hematoxylin and eosin staining, number and diameter of the centronucleated, regenerating myofibers), muscle fibrosis (vimentin‐positive area, Masson modified trichrome staining positive area), and muscle strength (analysis of fast twitch strength). RESULTS: The level of fibrosis was more than 50% lower in the exercise and decorin groups than in the control (P<0.05). The decorin group showed the highest number of regenerated, new myofibers, and the highest muscle strength. All of the exercise groups, regardless of the starting time of exercise, also showed significant improvement in regeneration and strength. However, the exercise group starting 14 days after the laceration showed the best results. CONCLUSIONS: Stretching exercises after a muscle laceration injury has a strong antifibrotic effect, as much as a well‐known antifibrotic agent, decorin. According to the results, the best time to begin stretching exercises is 14 days after laceration for antifibrosis and muscle regeneration.