Effect of ibuprofen on the healing phase of experimental myocardial infarction in the rat

Gel network comprising UV crosslinked PLGA-b-PEG-MA nanoparticles for ibuprofen topical delivery

Ibuprofen is a non-steroidal anti-inflammatory drug for the treatment of Rheumatoid Arthritis and osteoarthritis. In this study, we prepared topical gel network for enhancement of ibuprofen penetration, maintenance of controlled release and increased patient compliance. Nanoparticles containing ibuprofen were prepared by means of emulsion formation/solvent diffusion method using synthesized copolymer. Nanoparticles were then conjugated with aminoethylmethacrylate, resulting in ibuprofen-loaded nanoparticles in PLGA-b-PEG-MA structure. Ibuprofen-loaded gel networks were developed by crosslinking nanoparticles via UV exposure. Suitability for topical application has been assessed through characterization of particle size, zeta potential, morphology, encapsulation efficiency, in vitro release, cytotoxicity and enhancement of in vitro wound healing. The mean diameter of nanoparticles was measured as 230 ± 20 nm. Gel network formulations with higher particle size (2800 ± 350 nm) and zeta potential (39.8 ± 9.2 mV), depending on conjugation of methacrylate within copolymeric structure, and having encapsulation efficacy of 73.6 ± 2.8% were prepared. The in vitro release of ibuprofen was sustained for more than 7 hours. Gel network improved collagen synthesis, type I collagen mRNA expression and fibrosis in dose dependent manner. Based on this, we can conclude that PLGA-b-PEG gel network might be a promising systems for the local delivery of ibuprofen in RA patients.

Effect of a selective aldosterone receptor antagonist in myocardial infarction

Myocardial infarction (MI) initiates adaptive tissue remodeling, which is essential for heart function (such as infarct healing) but is also important for maladaptive remodeling (for example, reactive fibrosis and left ventricular dilation). The effect of aldosterone receptor antagonism on these processes was evaluated in Sprague-Dawley rats using eplerenone, a selective aldosterone receptor antagonist. Infarct healing and left ventricular remodeling were evaluated at 3, 7, and 28 days after MI by determination of the diastolic pressure-volume relationship of the left ventricle, the infarct-thinning ratio, and the collagen-volume fraction. Eplerenone did not affect reparative collagen deposition as was evidenced by a similar collagen volume fraction in the infarcted myocardium between eplerenone and vehicle-treated groups at 7 and 28 days post-MI. In addition, the thinning ratio, which is an index of infarct expansion, was comparable between the eplerenone and vehicle-treated animals at 7 and 28 days post-MI. A protective effect of eplerenone was demonstrated at 28 days post-MI, where reactive fibrosis in the viable myocardium was reduced in eplerenone-treated animals compared with vehicle-treated animals. Thus aldosterone receptor antagonism does not retard infarct healing but rather protects against maladaptive responses after MI.

Nonsteroidal anti-inflammatory drugs after acute myocardial infarction. DAVIT Study Group. Danish Verapamil Infarction Trial

The effect of nonsteroid anti-inflammatory drugs (NSAIDs) after acute myocardial infarction was studied in a retrospective study of 88 patients who were receiving regular NSAID treatment at randomization in the Danish Verapamil Infarction Trial II. There were no significant differences in mortality or major events between NSAID-treated patients versus controls (1,687); however, in a multivariate analysis a nonsignificant beneficial trend in favor of NSAIDs was observed.

The influence of NSAIDs on experimental intestinal anastomoses

Limiting degradation of collagen during the initial phase of wound healing is expected to improve postoperative intestinal strength and thereby decrease chances for anastomotic dehiscence. We studied the influence of four nonsteroid anti-inflammatory drugs on the healing of intestinal anastomoses in rats, with special regard to changes of collagen levels around the anastomoses. Four experimental groups of 20 rats each received daily oral doses of piroxicam, ibuprofen, aspirin, or indomethacin and were compared with a control group. Animals were sacrificed 3 or 7 days after operation. Both morbidity and mortality rate in the experimental groups were high. Collagen, measured as hydroxyproline, levels in anastomotic and adjoining 1-cm intestinal segments were compared with concentrations in control segments resected during operation. After an initial decrease on day 3, hydroxyproline concentrations increased on day 7. In the colon the lowering of hydroxyproline concentrations, which was more pronounced than in the ileum, was significantly reduced by administration of piroxicam and ibuprofen, both in the anastomosis and its proximal segment. On day 7, the increase of hydroxyproline concentrations in the ileum was inhibited by administration of anti-inflammatory drugs. It is concluded that nonsteroidal anti-inflammatory drugs may limit postoperative degradation of collagen in colonic anastomoses, but at the same time may increase the rat's susceptibility to surgical infections.