Nanosized complexation assemblies housed inside reverse micelles churn out monocytic delivery cores for bendamustine hydrochloride.

OBJECTIVE: We explore a plausible method of targeting bendamustine hydrochloride (BM) to circulatory monocytes by exploiting their intrinsic endocytic/phagocytic capability.

METHODS: We do so by complexation of sodium alginate and chitosan inside dioctyl sulfo succinate sodium (AOT) reverse micelles to form bendamustine hydrochloride loaded nanoparticles (CANPs). Dynamic light scattering, electrophoretic mobility and UV spectroscopy were used to detail intra-micellar complexation dynamics and to prove that drug was co-captured during interaction of carbohydrate polymers. A fluorescent conjugate of drug (RBM) was used to trace its intracellular fate after its loading into nanoparticles.

RESULTS: CANPs were sized below 150nm, had 75% drug entrapment and negative zeta potential (-30mV). Confocal microscopy demonstrated that developed chitosan alginate nanoparticles had the unique capability to carry BM specifically to its site of action. Quantitative and mechanism based cell uptake studies revealed that monocytes had voracious capacity to internalize CANPs via simultaneous scavenger receptor based endocytic and phagocytic mechanism. Comparative in vitro pharmacokinetic studies revealed obtainment of significantly greater intracellular drug levels when cells were treated with CANPs. This caused reduction in IC50 (22.5±2.1μg/mL), enhancement in G2M cell cycle arrest, greater intracellular reactive oxygen species generation, and increased apopotic potential of bendamustine hydrochloride in THP-1 cells.

CONCLUSION: Selective monocytic targeting of bendamustine hydrochloride using carbohydrate constructs can prove advantageous in case of leukemic disorders displaying overabundance of such cells.