Synthesis and in vitro evaluation of melatonin entrapped PLA nanoparticles: An oxidative stress and T‐cell response using golden hamster

Abstract This study was carried out to evaluate the effects of melatonin entrapped PLA nanoparticles (Mel‐NPs) and pure Mel on impact of reactive oxygen species (ROS), blastogenic responses (%SR) in terms of proliferation of splenocytes. ROS have been proposed to play an important role in balancing the pro‐ and antioxidant homeostasis during different physiological condition of organism. Melatonin has been suggested as an effective free radical scavenger that may have an important role during this process. Mel‐NPs were prepared by using emulsification (o/w) nanoprecipitation method and their physicochemical characterizations were studied for evaluation of particle size and encapsulation efficiency by using SEM, TEM, particle size analyzer, DSC and FTIR. The TEM micrograph showed excellent findings regarding size, shape, encapsulation efficiency and difference between pure PLA nanoparticles and Mel‐NPs. The SEM micrographs of Mel‐NPs showed spherical shape, smooth surfaces and the homogeneous particle size distribution. In TEM micrograph, the average diameter of Mel‐NPs was found to be 36 ± 8 nm with ∼78% (w/w) of entrapment efficiency. The size of pure PLA nanoparticles was found to be larger as compared to Mel‐NPs which confirm that the drug supports the reduction of the size of Mel‐NPs. In in vitro study, we observed that Mel‐NPs significantly reduce the level of ROS in splenocytes and increased the level %SR at 96 h of splenocytes culture as compared to the culture with pure Mel. Thus our results propose high clinical value for improvement of depressed immunity by Mel‐NPs. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 103A: 3034–3044, 2015.