Immunoengineering with Ginseng Polysaccharide Nanobiomaterials through Oral Administration in Mice

Plant polysaccharides (PS) such as American ginseng polysaccharide (GPS) have drawn immense interest in the field of immunoengineering, as they offer a way to actively control immune cell behavior and stimulation. These pharmacological activities have been limited by PS's inherent physicochemical properties including large molecular size, heterogeneity, and poor solubility. In this work, we hypothesized that by nanosizing and encapsulating GPSs, we could enhance their immunomodulation by increased penetration and absorption through the GI tract. Herein, GPS nanoparticles (NPs) of average size 20 nm (± 4 nm) were prepared using a microfluidic approach, then encapsulated within porous nanospheres (diameter 180 ± 10 nm) of biodegradable gelatin to enhance their oral delivery. To locate the GPS NPs inside the gelatin, we encapsulated fluorescent-labeled GPS in gelatin and analyzed using confocal microscopy. An in vitro investigation on tumor induced macrophage cell lines showed a concentration dependent enhanced immunostimulation with the encapsulated GPS NPs. The immunomodulation was then studied for different formulations of GPS through oral gavage in Swiss albino mice. The results showed that the production of proinflammatory mediators in blood samples was significantly increased for the encapsulated GPS in a dose- and time-dependent manner compared to other GPS treatments. This study shows that GPS and potentially other PS systems' immunomodulation properties can be significantly enhanced for use in simple oral drug delivery.