Preparation and in‐vitro/in‐vivo evaluation of surface‐modified poly (lactide‐co‐glycolide) fluorescent nanoparticles

Objective The aim was to develop biodegradable nanoparticles suitable for cellular delivery of chemotherapeutic drugs. Methods Poly (lactide‐co‐glycolide) (PLGA) nanoparticles were prepared using a modified solvent evaporation method. Chitosan and calcium chloride were tested as surface modifiers. Coumarin‐6 was incorporated into some formulations as a fluorescent marker. Key findings The median size of the particles was between 400 nm and 7 μm, and scanning electron microscope pictures showed that the particles were smooth and spherical. The zeta potentials of the particles with and without surface modifier ranged between ‐25.7 mV and ‐7.0 mV, respectively. Fluorescence microscopy and flow cytometry (FACS) analysis showed that smaller surface‐modified particles were efficiently internalised by neoplastic 4T1 cells. Image analysis of frozen tissue sections from Balb/c mice given nanoparticles via the tail vein showed that the particles were distributed preferentially into the lungs, followed by the liver, spleen, kidney and heart. Conclusions Chitosan‐modified PLGA nanoparticles showed significant uptake by neoplastic 4T1 cells, and were distributed to several major organs frequently seen as sites of cancer metastasis in mice.