Transmission electron microscopy (TEM) and atomic force microscopy (AFM) were used to evaluate the morphology and suspension of the PLGA nanocapsules. Rats were pretreated (15 min) with an intra-TMJ injection of unloaded 15d-PGJ2 or 15d-PGJ2-NC at concentrations of 10, 100 or 1000 pg followed by an ipsilateral intra-TMJ injection of 1.5%formalin. The nociceptive behavioral response was observed during 45 min; animals were then sacrificed and the periarticular tissue was removed for IL-1尾 measurements.
TEM and AFM analyses showed that 15d-PGJ2-NC is spherical without any aggregates or adhesion confirming that this formulation is a good drug carrier system for 15d-PGJ2. Pretreatment with 15d-PGJ2-NC (100 and 1000 pg/TMJ), but not unloaded 15d-PGJ2, was found to significantly decrease the release of IL-1尾 cytokine and the animals鈥?nociceptive behavioral response induced by intra-TMJ injection of formalin.
The compound 15d-PGJ2-NC might be used as a potential antinociceptive and anti-inflammatory agent to treat temporomandibular disorders in clinical practice.