Engineered Nanoparticles for Rapid Delivery of Betulinic Acid in MDA MB 231 and HEp-2 Cancer Cell Lines

Introduction: A range of triterpenoids have gained attention in cancer chemotherapy due to promising pre-clinical results. Triterpenoids are however constrained in therapeutics for both the solubility and permeability... [ view full abstract ]

Introduction: A range of triterpenoids have gained attention in cancer chemotherapy due to promising pre-clinical results. Triterpenoids are however constrained in therapeutics for both the solubility and permeability limitations. Betulinic acid (BA) is a pentacyclic triterpenoid available in Betula alba (white birch) bark. BA is enlisted under the RAID (Rapid Access to Intervention Development) program of NCI, USA. The compound is a strong inhibitor of topoisomerase and induces caspase activation and mitrochondrial membrane damage. BA is widely available and economic but suffers seriously in bio-pharmaceutics. Smart nanoparticle drug delivery devices were therefore conceived as one solution for BA delivery. Lactoferrin was used for nanoparticle ligand tethering for successful particle propagation up to the cancer cell nucleus.
Methods: PLGA nanoparticles loaded with BA (BAnps) were prepared in modified solvent diffusion method using PLF 127 as a stabilizer. Lactoferrin conjugation on BAnps (Lf-BAnps) was achieved in EDC/NHS coupling reactions. Nanoparticles were characterized in DLS, AFM, TEM, XRD, FTIR and SDS-PAGE. In-vitro anticancer efficacy was evaluated in two metastatic cancer cell lines: MDA-MB-231 and Hep-2.
Results and Discussion: The average particle size of Lf-BAnps in DLS was 120 nm. The entrapment efficiency of BA (75.42%) and non-fickian release pattern were determined by RP HPLC. The FT-IR and SDS-PAGE analysis confirmed lactoferrin interactions with BAnps. Lf-BAnps showed significantly strong antiproliferative and cytotoxic effects on both the cancer cell lines (IC50 4.0 µg/ml). Time-dependent uptake and quantitative count in flow-cytometry showed early time-point intracellular entry of Lf-BAnps. Specific cellular localization was confirmed by confocal microscopy. Increased sub-G1 population and decreased G2/M population indicating the apoptotic potential and cellular arrest of Lf-BAnps on cancer cells. Rapid localization and lactoferrin bio-functionalization in nanoscale has proved as one successful strategy in chemotherapeutic drug targeting.