Synergistic action of lactoferrin in enhancing the safety and effectiveness of docetaxel treatment against prostate cancer.

BACKGROUND: Tumor metastasis is promoted by an immunosuppressive environment. Lactoferrin (Lf) is known to regulate immunological activity in tumor cells and inhibit processes associated with tumor metastasis. A delivery of lactoferrin with docetaxel (DTX) in prostate cancer cells in the form of DTX-loaded lactoferrin nanoparticles (DTX-LfNPs) would provide a dual activity wherein the lactoferrin affects metastasis and DTX chemotherapeutically inhibits mitosis and cell division. METHODS: DTX-LfNPs were prepared using sol-oil chemistry, and particles were characterized using transmission electron microscopy. Antiproliferation activity was analyzed in prostate cancer Mat Ly Lu cells. The target localization and efficacy of DTX-LfNPs were studied in an orthotopic prostate cancer induced by Mat Ly Lu cells in a rat model. Biomarkers were estimated using ELISA and biochemical reactions. RESULTS: DTX was loaded in pure Lf nanoparticles without involving any chemical modification and conjugation, thus when these nanoparticles are delivered in cancer cells both DTX and Lf will be present in biologically active forms. DTX-LfNps exhibit a spherical morphology of dimension of 60 ± 10 nm with DTX Encapsulation Efficiency of 62.06 ± 4.07%. Competition experiments using soluble Lf confirm that DTX-LfNPs enter prostate cancer cells through the Lf receptor. DTX-LfNPs exhibit an improved anti-proliferative activity by 2.5 times compared to DTX. Further, analysis of the bioavailability of the drug in the prostate showed that DTX-LfNPs increased drug bioavailability in the prostate by two times more than the DTX. The analysis of efficacy in the Mat Ly Lu cells-induced orthotopic prostate cancer model showed that DTX-LfNPs significantly enhanced the anti-cancer activity compared to DTX in terms of regression of weight and volume of prostate tissue, the efficacy was confirmed by histochemical analysis. Lf provides synergistic activity along with DTX in inhibiting metastasis as assessed by the reduction of lactate dehydrogenase, alkaline phosphatase, TNF alpha, and IFNγ. LfNPs facilitate higher DTX localization along with Lf-mediated protection from DTX-associated toxicity to neutrophils and kidneys as assessed by C-reactive protein, creatinine, and uric acid. Thus, DTX LfNPs show a dual action by enhancing DTX bioavailability in prostate along with Lf-mediated suppression of metastasis as well as DTX-associated toxicity. CONCLUSION: In conclusion, DTX-LfNPs enhance the bioavailability of DTX in the prostate along with Lf-assisted improvement in inhibition of tumor metastasis and drug-associated toxicity.

Carboplatin- and Etoposide-Loaded Lactoferrin Protein Nanoparticles for Targeting Cancer Stem Cells in Retinoblastoma In Vitro.

Purpose: Cancer stem cells (CSCs) are known to contribute to tumor relapses by virtue of their chemoresistance. With the knowledge that nanoformulations can overcome drug resistance, we evaluated the efficacy and cytotoxicity of clinical-grade carboplatin (CPT)- and etoposide (ETP)-loaded lactoferrin nanoparticles (Lf-Nps) on total, CD133-enriched (non-CSC), and CD133-depleted (CSC) populations of retinoblastoma (Rb) Y79 cells. Methods: Physicochemical properties of drug-loaded Lf-Nps were measured with transmission electron microscopy and attenuated total reflectance-Fourier transform infrared. The encapsulation efficiency, uptake, and release of drug-loaded Lf-Nps were measured using high-performance liquid chromatography and a UV-visible spectrophotometer. Cytotoxicity of the standard and drug-loaded Lf-Nps was evaluated by the MTT assay. Results: The mean (SD) size and encapsulation efficiency of Lf-CPT and Lf-ETP were 61.2 (3.94) nm, 60% and 45.15 (5.85) nm, 38%, respectively, and the drug release efficiency was highest at pH 6. The increased drug uptake and lower release of drug-loaded Lf-Nps were observed in CSC and non-CSC populations compared to their standard forms. The relative increase of drug uptake and sustained intracellular retention of the drug-loaded Lf-Nps compared to standard drugs showed an enhanced cytotoxicity up to 50%, especially in Rb Y79 CSCs (IC50: CPT, 230.3; Lf-CPT, 118.2; ETP, 198.1; and Lf-ETP, 129) compared to non-CSCs. Conclusions: Our study documents an increase in drug uptake, retention, and cytotoxicity of Lf-CPT and Lf-ETP on Y79 CSCs and non-CSCs as compared to their standard drugs in vitro. The reversal of chemoresistance in the CSC population by nanoformulation appears promising with the potential to pave the way for improved targeted therapy and better clinical outcomes.