Journal

European Journal of Pharmaceutics and Biopharmaceutics

Papers (12)

Wavelength dependent photo-cytotoxicity to ovarian carcinoma cells using temoporfin loaded tetraether liposomes as efficient drug delivery system

5,10,15,20-Tetrakis(3-hydroxyphenyl)chlorin (mTHPC; temoporfin) is one of the most potent second-generation photosensitizers available today for the treatment of a variety of clinical disorders and has a unique capability of being activated at different wavelengths. However, due to its highly lipophilic nature, poor solubility in the aqueous media and poor bioavailability limits its application in anticancer therapies. To overcome these potential issues, we developed three different liposomal formulations with mTHPC encapsulated in hydrophobic milieu thus increasing the bioavailability of the drug. The prepared formulations were characterized in terms of hydrodynamic diameter, surface charge, encapsulation efficiency, and stability studies. The mean size of the liposomes was found to be in the nanoscale range (about 100 nm) with zeta potential ranging from -6.0 to -13.7 mV. mTHPC loaded liposomes were also evaluated for morphology using atomic force microscopy (AFM) and cryo-transmission electron microscopy (cryo-TEM). Data obtained from the hemocompatibility experiments showed that these formulations were compatible with blood showing less than 10% hemolysis and coagulation time lower than 40 s. The results obtained from the single-cell gel electrophoresis assay also demonstrated no incidence of genotoxicity. Photodynamic destruction of SK-OV-3 cells using mTHPC loaded liposomes showed a dose-response relationship upon irradiation with two different wavelength lights (blue λ = 457 nm & red λ = 652 nm). A 10-fold pronounced effect was produced when liposomal formulations were irradiated at 652 nm as compared to 457 nm. This was also evaluated by the quantitative assessment of reactive oxygen production (ROS) using fluorescence microscopy. The qualitative assessment of PDT pre- and post-irradiation was visualized using confocal laser scanning microscopy (CLSM) which demonstrated an intense localization of mTHPC liposomes in the perinuclear region. Chick chorioallantoic membrane assay (CAM) was used as an alternative in-ovo model to demonstrate the localized destruction of tumor microvasculature. Overall, the prepared nanoformulation is a biocompatible, efficient and well characterized delivery system for mTHPC for the safe and effective PDT.

The effects of ligand distribution and density on the targeting properties of dual-targeting folate/biotin Pluronic F127/Poly (lactic acid) polymersomes

Targeted drug delivery systems modified with two or more ligands were expected to have better anti-tumor ability than those with just one ligand due to the complexity and heterogeneity of tumors. Thus, dual-targeting Pluronic/poly (lactic acid) polymersomes containing biotin (BT) and folic acid (FA) ligands (BT/FA-F127-PLA) were designed to study their targeting properties over human ovarian cancer cells (OVCAR-3). Two kinds of dual-ligand targeting polymersomes, BT/FA-F127-PLA and (BT + FA)-F127-PLA, were prepared to study the effect of the dual-ligand distribution on the cell targeting of polymersomes. BT/FA-F127-PLA had two ligands distributed in the same polymersomes whereas (BT + FA)-F127-PLA had two ligands distributed in different polymersomes. The in vitro cytotoxicity and cellular uptake, and in vivo pharmacokinetic behaviors of BT/FA-F127-PLA were superior to those of (BT + FA)-F127-PLA. It suggested that biotin and folate ligands distributed on the same polymersomes could have the targeting effect of synergistic promotion. Further experiments on cell uptake mechanisms of polymersomes showed that the uptake of targeted polymersomes was associated with energy-dependent endocytosis, involving clathrin, caveolin protein, macropinocytosis and ligand receptor-mediated endocytosis. In addition, the effect of different density ratios of dual ligands for BT/FA-F127-PLA was further studied. The results showed that the cellular targeting effect of BT/FA-F127-PLA was the strongest when the molar ratio of biotin to folic acid was 7.5 %: 7.5 %. In conclusion, BT/FA-F127-PLA dual-targeting polymersomes could be good candidates as targeted drug delivery carriers.

Amine-functionalized mesoporous silica nanoparticles decorated by silver nanoparticles for delivery of doxorubicin in breast and cervical cancer cells

Nanocarriers have demonstrated promising potential in the delivery of various anticancer drugs and in improving the efficiency of the treatment. In this study, silver nanoparticles (AgNPs) were green-synthesized using the extracts of different parts of the pomegranate plant, including the peel, flower petals, and calyx. To obtain the most efficient extract used for the green synthesis of AgNPs, all three types of synthesized nanoparticles were characterized. Then, (3-Aminopropyl) triethoxysilane-functionalized mesoporous silica nanoparticles (MSNs-APTES) decorated with AgNPs were fabricated via a one-pot green-synthesis method. AgNPs were directly coated on the surface of MSNs-APTES by adding pomegranate extract enriched with a source of reducing agent leading to converting the silver ion to AgNPs. The MSN-APTES-AgNPs (MSNs-AgNPs) have been thoroughly characterized using nanoparticle characterization techniques. In addition, DNA cleavage and hemolysis activities of the synthesized nanoparticles were analyzed, confirming the biocompatibility of synthesized nanoparticles. The Doxorubicin (DOX, as a breast/cervical anti-cancer drug) loading (42.8%) and release profiles were investigated via UV-visible spectroscopy. The fibroblast, breast cancer, and cervical cancer cells' viability against DOX-loaded nanoparticles were also studied. The results of this high drug loading, uniform shape, and small functionalized nanoparticles demonstrated its great potential for breast and cervical cancer management.

Simple ROS-responsive micelles loaded Shikonin for efficient ovarian cancer targeting therapy by disrupting intracellular redox homeostasis

Ovarian cancer is the most common malignant tumor in women. Shikonin (SHK), an herbal extract from Chinese medicine, shows promise in treating ovarian cancer by inducing reactive oxygen species (ROS). However, its clinical use is limited by poor tumor targeting and low bioavailability, and its therapeutic potential is further compromised by the elevated levels of antioxidants such as glutathione (GSH) within tumor cells. In this study, a novel formulation of ROS-responsive micelles loaded with SHK was developed using hyaluronic acid-phenylboronic acid pinacol ester conjugation (HA-PBAP) for targeted therapy of ovarian cancer through disruption of intracellular redox homeostasis. The SHK@HA-PBAP exhibits targeted delivery to ovarian cancer cells through the interaction between HA and CD44 receptors. Upon internalization by cancer cells, the high levels of intracellular ROS triggered the degradation of SHK@HA-PBAP and simultaneously released SHK and generated GSH scavenger quinone methide (QM). The SHK and QM released from the SHK@HA-PBAP effectively induce the production of ROS and deplete intracellular GSH, leading to the disruption of intracellular redox homeostasis and subsequent induction of cell death. These characteristics collectively inhibit the growth of ovarian cancer. In vitro and in vivo studies have demonstrated that SHK@HA-PBAP micelles exhibit superior antitumor efficacy compared to free SHK in both A2780 cells and A2780 tumor-bearing mice. The ROS-responsive SHK@HA-PBA presents a promising therapeutic approach for the treatment of ovarian cancer.

Development of Trastuzumab-coupled, siRNA encapsulating mPolyplexes targeting HER2 overexpressing cancer cells

Over the past decades, significant advancements have been made in various medical fields; however, ovarian cancer (OC) remains inadequately addressed, predominantly relying on relatively toxic cytostatic treatments. In this study, we applied newly developed poly(β-amino) esters (PBAEs) for siRNA delivery. As recent literature has shown, the introduction of a hydrophobic, unsaturated fatty acid together with polycationic spermines as the PBAE side chains are leading to a favourable transfection efficiency, and the resulting materials form a unique class of micelleplexes, termed micelle-embedded polyplexes (mPolyplexes). Here, such mPolyplexes were modified post-particle formation with the approved monoclonal antibody Trastuzumab for HER2 targeting, as supported by a receptor binding analysis through fluorescence shift assay. Physicochemical analysis revealed suitable hydrodynamic diameters of modified mPolyplexes, as determined by dynamic light scattering. Improved cellular uptake when targeted with Trastuzumab was optimized by applying Design of Experiment (DoE). We demonstrated superior gene silencing efficiency of EGFR as well as PLK1, both involved in OC progression, with knockdown values exceeding 82% and 70%, respectively. These findings were corroborated by a relevant cell migration assay. The macroscopic impact after PLK1 silencing on epithelial-mesenchymal transition (EMT) was visualized using confocal microscopy. This work addresses critical questions in the field of ovarian cancer therapy and confirms the suitability of siRNA encapsulating PBAE nanocarriers as promising non-viral vectors.

Phosphatidylserine targeting peptide-functionalized pH sensitive mixed micelles for enhanced anti-tumor drug delivery

In recent decades, targeted drug delivery systems (TDDS) have been widely used as an ideal method of improving therapeutic effects and reducing systemic side effects of chemotherapeutic agents. Historically, a handful of methods have been developed to further improve the targeting ability of delivery systems. Thus, in this study, two methods, taking advantage of tumor characteristics, were used for the creation of a multi-targeted delivery system. The first was the fabrication of pH-sensitive micelles, lending the ability to increase drug release by exploiting the acidic tumor environment. The second method was through utilization of the surface-exposed phosphatidylserine (PS) of tumors, which is normally found in the inner leaflet in healthy cells. Using PS as a target site, PS binding peptide (PSBP-6) was conjugated to pH-sensitive mixed micelles, (consisting of poly (ethylene glycol)-b-poly (D, L-lactide) (PEG-PDLLA) and poly (ethylene glycol)-b-poly (L-histidine) (PEG-PHIS)). After successful preparation of micelles, paclitaxel (PTX), a common chemotherapeutic agent, was selected to measure drug loading capacity and encapsulation efficiency, showing 7.9% and 83.5%, respectively. The in vitro release of PTX from mixed micelles at pH 5.0, 6.5, and 7.4 was 78.1, 56.8, and 51.4%, respectively, indicating acid-triggered drug release. The PSBP-6-modified, mixed micelles exhibited significantly enhanced in vitro cytotoxicity and demonstrated more efficient cellular uptake compared to unmodified mixed micelles in the HeLa cell line. Moreover, pharmacokinetic, in vivo biodistribution, and fluorescence imaging studies showed that PSBP-6-PEG-PDLLA/PEG-PHIS mixed micelles provide prolonged time in blood circulation and enhanced tumor accumulation. These results suggest that the use of PS as a novel targeting site is advantageous, and that these new multi-targeted mixed micelles show great potential for realization of broad prospects in the targeted treatment of tumors for chemotherapeutic delivery.

Publisher

Elsevier BV

ISSN

0939-6411