Surface engineered nanostructured lipid carriers for targeting MDR tumor: Part II. In vivo biodistribution, pharmacodynamic and hematological toxicity studies

Irinotecan loaded nanostructured lipid carrier (NLC-Ir) was surface decorated with hyaluronic acid graft polymer. Hyaluronic acid is a biocompatible, non-antigenic and hydrophilic, CD-44 ligand that can impart many useful features to the nanocarrier for anticancer drug delivery. The present investigation demonstrated that hyaluronic acid coated HA-NLC had significantly lower haemolytic potential as compared to uncoated NLC. Further, HA-NLC had a reduced plasma protein interaction and low macrophage uptake. The in vivo tumor targeting and pharmacodynamics efficacy of HA-NLC was studied in Ehrlichʹs Ascites Tumor (EAT) allograft model. Radio scintigraphic biodistribution studies revealed that HA-NLC carrier got accumulated in the tumor tissues in good proportion. Additionally, the content of radioactivity associated with tumor tissues remained constant at 2, 4 and 24 h (2.41, 2.48 and 2.47%, respectively), while it got reduced in other organs. Furthermore, tumor to muscle ratio of radioactivity suggested a better accumulation of HA-NLC in tumor tissues that was significantly enhanced (P < 0.05) with time. In vivo antitumor activity of hyaluronan coated HA-NLC-Ir was 5.8 and 2.6 times higher as compared to control and free drug solution respectively. Furthermore, encapsulation of irinotecan in HA-NLC-Ir nanocarrier was found to have reduced the thrombocytopenia and neutropenia associated with free irinotecan. Thus, it can be inferred that the hyaluronic acid decorated nanocarrier can provide a haemo-compatible, non-toxic and target based delivery system for the effective management of cancer.