Octreotide-Targeted Lcn2 siRNA PEGylated Liposomes as a Treatment for Metastatic Breast Cancer

Lcn2 overexpression in metastatic breast cancer (MBC) can lead to cancer progression by inducing the epithelial-to-mesenchymal transition and enhancing tumor angiogenesis. In this study, we engineered a PEGylated liposomal system encapsulating lipocalin 2 (Lcn2) small interfering RNA (Lcn2 siRNA) for selective targeting MBC cell line MCF-7 and triple-negative breast cancer cell line MDA-MB-231. The PEGylated liposomes were decorated with octreotide (OCT) peptide. OCT is an octapeptide analog of somatostatin growth hormone, having affinity for somatostatin receptors, overexpressed on breast cancer cells. Optimized OCT-targeted Lcn2 siRNA encapsulated PEGylated liposomes (OCT-Lcn2-Lipo) had a mean size of 152.00 nm, PDI, 0.13, zeta potential 4.10 mV and entrapment and loading efficiencies of 69.5% and 7.8%, respectively. In vitro uptake and intracellular distribution of OCT-Lcn2-Lipo in MCF-7 and MDA-MB-231 and MCF-12A cells demonstrated higher uptake for the OCT-targeted liposomes at 6 h by flow cytometry and confocal microscopy. OCT-Lcn2-lipo could achieve approximately 55-60% silencing of Lcn2 mRNA in MCF-7 and MDA-MB-231 cells. OCT-Lcn2-Lipo also demonstrated in vitro anti-angiogenic effects in MCF-7 and MDA-MB-231 cells by reducing VEGF-A and reducing the endothelial cells (HUVEC) migration levels. This approach may be useful in inhibiting angiogenesis in MBC.

Hyaluronic Acid-Targeted Stimuli-Sensitive Nanomicelles Co-Encapsulating Paclitaxel and Ritonavir to Overcome Multi-Drug Resistance in Metastatic Breast Cancer and Triple-Negative Breast Cancer Cells

Active targeting and overcoming multi-drug resistance (MDR) can be some of the important attributes of targeted therapy for metastatic breast cancer (MBC) and triple-negative breast cancer (TNBC) treatment. In this study, we constructed a hyaluronic acid (HA)-decorated mixed nanomicelles-encapsulating chemotherapeutic agent paclitaxel (PTX) and P-glycoprotein inhibitor ritonavir (RTV). HA was conjugated to poly (lactide) co-(glycolide) (PLGA) polymer by disulfide bonds (HA-ss-PLGA). HA is a natural ligand for CD44 receptors overexpressed in breast cancer cells. Disulfide bonds undergo rapid reduction in the presence of glutathione, present in breast cancer cells. The addition of RTV can inhibit the P-gp and CYP3A4-mediated metabolism of PTX, thus aiding in reversing MDR and sensitizing the cells toward PTX. An in vitro uptake and cytotoxicity study in MBC MCF-7 and TNBC MDA-MB-231 cell lines demonstrated the effective uptake of the nanomicelles and drug PTX compared to non-neoplastic breast epithelium MCF-12A cells. Interestingly, in vitro potency determination showed a reduction in mitochondrial membrane potential and reactive oxygen species in breast cancer cell lines, indicating effective apoptosis of cancer cells. Thus, stimuli-sensitive nanomicelles along with HA targeting and RTV addition can effectively serve as a chemotherapeutic drug delivery agent for MBC and TNBC.

Preparation and characterization of lutein loaded folate conjugated polymeric nanoparticles

AIM

To prepare and characterise lutein-loaded polylactide-co-glycolide-polyethylene glycol-folate (PLGA-PEG-FOLATE) nanoparticles and evaluate enhanced uptake in SK-N-BE(2) cells.

METHODS

Nanoparticles were prepared using O/W emulsion solvent evaporation and characterised using DLS, SEM, DSC, FTIR and in-vitro release. Lutein-uptake in SK-N-BE(2) cells was determined using flow-cytometry, confocal-microscopy and HPLC. Control was lutein PLGA nanoparticles.

RESULTS

The size of lutein-loaded PLGA and PLGA-PEG-FOLATE nanoparticles were 189.6 ± 18.79 nm and 188.0 ± 4.06 nm, respectively. Lutein entrapment was ∼61%(w/w) and ∼73%(w/w) for PLGA and PLGA-PEG-FOLATE nanoparticles, respectively. DSC and FTIR confirmed encapsulation of lutein into nanoparticles. Cellular uptake studies showed ∼1.6 and ∼2-fold enhanced uptake of lutein from PLGA-PEG-FOLATE nanoparticles compared to PLGA nanoparticles and lutein, respectively. Cumulative release of lutein was higher in PLGA nanoparticles (100% (w/w) within 24 h) compared to PLGA-PEG-FOLATE nanoparticles (∼80% (w/w) in 48 h).

CONCLUSION

Lutein-loaded PLGA-PEG-FOLATE nanoparticles could be a potential treatment for hypoxic ischaemic encephalopathy.

Prodrugs and nanomicelles to overcome ocular barriers for drug penetration

INTRODUCTION

Ocular barriers hinder drug delivery and reduce drug bioavailability. This article focuses on enhancing drug absorption across the corneal and conjunctival epithelium. Both, transporter targeted prodrug formulations and nanomicellar strategy is proven to enhance the drug permeation of therapeutic agents across various ocular barriers. These strategies can increase aqueous drug solubility and stability of many hydrophobic drugs for topical ophthalmic formulations.

AREAS COVERED

The article discusses various ocular barriers, ocular influx, and efflux transporters. It elaborates various prodrug strategies used for enhancing drug absorption. Along with this, the article also describes nanomicellar formulation, its characteristic and advantages, and applications in for anterior and posterior segment drug delivery.

EXPERT OPINION

Prodrugs and nanomicellar formulations provide an effective strategy for improving drug absorption and drug bioavailability across various ocular barriers. It will be exciting to see the efficacy of nanomicelles for treating back of the eye disorders after their topical application. This is considered as a holy grail of ocular drug delivery due to the dynamic and static ocular barriers, restricting posterior entry of topically applied drug formulations.