Amphiphilic Poly(N-vinylpyrrolidone) Nanoparticles Conjugated with DR5-Specific Antitumor Cytokine DR5-B for Targeted Delivery to Cancer Cells

Combination of multivalent DR5 receptor clustering agonists and histone deacetylase inhibitors for treatment of colon cancer

Death Receptor 5 (DR5) targeted therapies offer significant promise due to their pivotal role in mediating the extrinsic pathway of apoptosis. Despite DR5 overexpression in various malignancies and the potential of tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL), clinical applications of anti-DR5 monoclonal antibodies (mAbs) have been hampered by suboptimal outcomes potentially due to lack of receptor clustering. To address the limitation, we developed N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer-based conjugates integrating multiple copies of DR5-targeting peptide (cyclic WDCLDNRIGRRQCVKL; cDR5) to enhance receptor clustering and apoptosis. Three conjugates with variable number of cDR5 were prepared and denoted as PH-cDR5 (high valence), PM-cDR5 (medium valence) and PL-cDR5 (low valence). Our studies in TRAIL-sensitive and resistant cancer cell lines demonstrated that the HPMA copolymer-peptide conjugates (P-cDR5) significantly improved DR5 receptor clustering and induced apoptosis effectively. In TRAIL-sensitive colon cancer cells (COLO205, HCT-116), P-cDR5 showed efficacy comparable to anti-DR5 mAb Drozitumab (DRO), but P-cDR5 outperformed DRO in TRAIL-resistant cells (HT-29), highlighting the importance of efficient receptor clustering. In COLO205 cells PM-cDR5 exhibited an IC50 of 94 pM, while PH-cDR5 had an even lower IC50 of 15 pM (based on cDR5 equivalent concentration), indicating enhanced potency of the multivalent HPMA copolymer-based system with a flexible polymer backbone in comparison with the IC50 for TRAIL at 0.12 nM. Combining P-cDR5 with valproic acid, a histone deacetylase inhibitor, resulted in further enhancement of apoptosis inducing efficacy, along with destabilizing mitochondrial membranes and increased sensitivity of TRAIL-resistant cells. These findings suggest that attaching multiple cDR5 peptides to a flexible water-soluble polymer carrier not only overcomes the limitations of previous designs but also offers a promising avenue for treating resistant cancers, pointing toward the need for further preclinical exploration and validation of this innovative strategy.

Synthesis, Molecular Docking, and Anticancer Screening of Ester-Based Thiazole Derivatives

This study investigates the potential of five compounds as novel anticancer agents. We examined their efficacy, mechanisms of action, and impact on various cancer cell lines, through a comprehensive set of experiments. Notably, compound 3e demonstrated superior activity compared to the positive control cisplatin, with a GI50 value of 6.3±0.7 μM against the breast cancer cell line (MCF-7). Compound 3b also displayed remarkable growth inhibition, yielding GI50 values of 8.7±0.2 μM (MCF-7) and 8.9±0.5 μM against the colon cancer cell line (HCT-116). Cell count experiments further confirmed the potent inhibitory effects of compounds 3e, 3b, and 3c on MCF-7 and HCT-116 cell growth. Compound 3e demonstrated a reduction of 55-60 % at GI50 and complete inhibition (100 %) at 2x GI50. Compound 3b exhibited 50-55 % reduction (GI50) and 90-95 % inhibition (2x GI50) in HCT-116 cells. Compound 3c displayed 75-80 % inhibition (2x GI50) and 35-40 % inhibition (GI50) in HCT-116 cells. In-depth mechanistic investigations unveiled valuable insights into the mode of action of compound 3e. The cell-cycle assay demonstrated G2/M phase arrest, DNA damage, and caspase-mediated apoptosis in both MCF-7 and HCT-116 cells. Caspase activation indicated a significant increase in apoptosis following exposure to compound 3e. Furthermore, compound 3e induced reactive oxygen species (ROS) production, influencing HCT-116 and MCF-7 cells differently. Elevated ROS production in HCT-116 cells and distinct effects in MCF-7 cells contribute to a deeper understanding of the cytotoxic mechanisms of compound 3e. Overall, these findings highlight the potential of the investigated compounds, particularly compound 3e, as effective inducers of apoptosis in cancer cells. Mechanistic insights into cell cycle arrest, caspase-mediated apoptosis, and ROS modulation provide a comprehensive understanding of their cytotoxic effects. This study offers significant contribution to the development of promising anticancer agents and their therapeutic applications.

Recent Applications of Amphiphilic Copolymers in Drug Release Systems for Skin Treatment

Amphiphilic copolymers (ACs) are versatile systems with self-assembling and aggregating properties, enabling the formation of nanomaterials (NMs) such as micelles, vesicles, nanocapsules, and nanogels. These materials have been extensively explored for the delivery of various drugs and active compounds, enhancing the solubility and permeation of poorly water-soluble drugs into skin tissue. This improvement facilitates the treatment of skin diseases, including chronic conditions like cancer, as well as infections caused by bacteria, fungi, and viruses. This review summarizes recent applications of ACs in skin treatment, with a particular focus on their use in anti-cancer drug therapy. It covers the synthesis, classification, and characterization of ACs using various experimental techniques. Additionally, it discusses recent research on different drug delivery pathways using ACs, including encapsulation efficiency, release behavior, characteristics, applications, and responses to various chemical and physical stimuli (both in vivo and in vitro). Furthermore, this review provides a comprehensive analysis of the effects of ACs NMs on several skin diseases, highlighting their potential as alternative treatments.

Toxicity Evaluation and Controlled-Release of Curcumin-Loaded Amphiphilic Poly-N-vinylpyrrolidone Nanoparticles: In Vitro and In Vivo Models

Curcumin attracts huge attention because of its biological properties: it is antiproliferative, antioxidant, anti-inflammatory, immunomodulatory and so on. However, its usage has been limited by poor water solubility and low bioavailability. Herein, to solve these problems, we developed curcumin-loaded nanoparticles based on end-capped amphiphilic poly(N-vinylpyrrolidone). Nanoparticles were obtained using the solvent evaporation method and were characterized by dynamic and electrophoretic light scattering, transmission electron (TEM) and atomic force (AFM) microscopy. The average particle size was 200 nm, and the ζ-potential was -4 mV. Curcumin-release studies showed that nanoparticles are stable in aqueous solutions. An in vitro release study showed prolonged action in gastric, intestinal and colonic fluids, consistently, and in PBS. In vitro studies on epidermoid carcinoma and human embryonic kidney cells showed that the cells absorbed more curcumin in nanoparticles compared to free curcumin. Nanoparticles are safe for healthy cells and show high cytotoxicity for glioblastoma cells in cytotoxicity studies in vitro. The median lethal dose was determined in an acute toxicity assay on zebrafish and was 23 μM. Overall, the curcumin-loaded nanoparticles seem promising for cancer treatment.

Doxorubicin-Loaded Polyelectrolyte Multilayer Capsules Modified with Antitumor DR5-Specific TRAIL Variant for Targeted Drug Delivery to Tumor Cells

Recently, biodegradable polyelectrolyte multilayer capsules (PMC) have been proposed for anticancer drug delivery. In many cases, microencapsulation allows to concentrate the substance locally and prolong its flow to the cells. To reduce systemic toxicity when delivering highly toxic drugs, such as doxorubicin (DOX), the development of a combined delivery system is of paramount importance. Many efforts have been made to exploit the DR5-dependent apoptosis induction for cancer treatment. However, despite having a high antitumor efficacy of the targeted tumor-specific DR5-B ligand, a DR5-specific TRAIL variant, its fast elimination from a body limits its potential use in a clinic. A combination of an antitumor effect of the DR5-B protein with DOX loaded in the capsules could allow to design a novel targeted drug delivery system. The aim of the study was to fabricate PMC loaded with a subtoxic concentration of DOX and functionalized with the DR5-B ligand and to evaluate a combined antitumor effect of this targeted drug delivery system in vitro. In this study, the effects of PMC surface modification with the DR5-B ligand on cell uptake both in 2D (monolayer culture) and 3D (tumor spheroids) were studied by confocal microscopy, flow cytometry and fluorimetry. Cytotoxicity of the capsules was evaluated using an MTT test. The capsules loaded with DOX and modified with DR5-B demonstrated synergistically enhanced cytotoxicity in both in vitro models. Thus, the use of the DR5-B-modified capsules loaded with DOX at a subtoxic concentration could provide both targeted drug delivery and a synergistic antitumor effect.

Recent Advances in the Development of Nanodelivery Systems Targeting the TRAIL Death Receptor Pathway

The TRAIL (TNF-related apoptosis-inducing ligand) apoptotic pathway is extensively exploited in the development of targeted antitumor therapy due to TRAIL specificity towards its cognate receptors, namely death receptors DR4 and DR5. Although therapies targeting the TRAIL pathway have encountered many obstacles in attempts at clinical implementation for cancer treatment, the unique features of the TRAIL signaling pathway continue to attract the attention of researchers. Special attention is paid to the design of novel nanoscaled delivery systems, primarily aimed at increasing the valency of the ligand for improved death receptor clustering that enhances apoptotic signaling. Optionally, complex nanoformulations can allow the encapsulation of several therapeutic molecules for a combined synergistic effect, for example, chemotherapeutic agents or photosensitizers. Scaffolds for the developed nanodelivery systems are fabricated by a wide range of conventional clinically approved materials and innovative ones, including metals, carbon, lipids, polymers, nanogels, protein nanocages, virus-based nanoparticles, dendrimers, DNA origami nanostructures, and their complex combinations. Most nanotherapeutics targeting the TRAIL pathway are aimed at tumor therapy and theranostics. However, given the wide spectrum of action of TRAIL due to its natural role in immune system homeostasis, other therapeutic areas are also involved, such as liver fibrosis, rheumatoid arthritis, Alzheimer's disease, and inflammatory diseases caused by bacterial infections. This review summarizes the recent innovative developments in the design of nanodelivery systems modified with TRAIL pathway-targeting ligands.

DR5-Selective TRAIL Variant DR5-B Functionalized with Tumor-Penetrating iRGD Peptide for Enhanced Antitumor Activity against Glioblastoma

TRAIL (TNF-related apoptosis-inducing ligand) and its derivatives are potentials for anticancer therapy due to the selective induction of apoptosis in tumor cells upon binding to death receptors DR4 or DR5. Previously, we generated a DR5-selective TRAIL mutant variant DR5-B overcoming receptor-dependent resistance of tumor cells to TRAIL. In the current study, we improved the antitumor activity of DR5-B by fusion with a tumor-homing iRGD peptide, which is known to enhance the drug penetration into tumor tissues. The obtained bispecific fusion protein DR5-B-iRGD exhibited dual affinity for DR5 and integrin αvβ3 receptors. DR5-B-iRGD penetrated into U-87 tumor spheroids faster than DR5-B and demonstrated an enhanced antitumor effect in human glioblastoma cell lines T98G and U-87, as well as in primary patient-derived glioblastoma neurospheres in vitro. Additionally, DR5-B-iRGD was highly effective in a xenograft mouse model of the U-87 human glioblastoma cell line in vivo. We suggest that DR5-B-iRGD may become a promising candidate for targeted therapy for glioblastoma.

In Vitro Assessment of Poly-N-Vinylpyrrolidone/Acrylic Acid Nanoparticles Biocompatibility in a Microvascular Endothelium Model

An amphiphilic copolymer of N-vinyl-2-pyrrolidone and acrylic acid-namely, p(VP-AA)-OD6000 (p(VP-AA))-was synthesized to prepare p(VP-AA) nanoparticles (NPs). Furthermore, the copolymer was linked with CFSE, and the so-prepared nanoparticles were loaded with the DiI dye to form D nanoparticles (DNPs). In this study, as demonstrated by immunofluorescence microscopy, immunofluorescence, and confocal microscopy, DNPs were readily taken up by human microvascular endothelial cells (HMEC-1) cells in a concentration-dependent manner. Upon uptake, both the CFSE dye (green stain) and the DiI dye (red stain) were localized to the cytoplasm of treated cells. Treatment with p(VP-AA) did not affect the viability of normal and challenged with LPS, HMEC-1 cells at 0.010 mg/mL and induced a dose-dependent decrease of these cells' viability at the higher concentrations of 0.033 and 0.066 mg/mL (p ≤ 0.01; p ≤ 0.001, respectively). Furthermore, we focused on the potential immunological activation of HMEC-1 endothelial cells upon p(VP-AA) NPs treatment by assessing the expression of adhesion molecules (E-Selectin, ICAM-1, and V-CAM). NPs treatments at concentrations utilized (p = NS) did not affect individual adhesion molecules' expression. p(VP-AA) NPs do not activate the endothelium and do not affect its viability at pharmacologically relevant concentrations.

Amphiphilic Poly-N-vinylpyrrolidone Nanoparticles as Carriers for Nonsteroidal, Anti-Inflammatory Drugs: Pharmacokinetic, Anti-Inflammatory, and Ulcerogenic Activity Study

Nanoparticles are increasingly utilized as drug delivery agents. Previously, we have developed a drug delivery system based on amphiphilic derivatives of poly-N-vinylpyrrolidone (PVP-OD4000) with excellent biocompatibility. In the current study, we assessed the pharmacokinetics, anti-inflammatory profile, and ulcerogenic potential of indomethacin (IMC)-loaded PVP-OD4000 nanoparticles compared to the free drug. Wistar male rats were utilized for a pharmacokinetics study and an anti-inflammatory study. Loaded IMC exhibited a slower elimination rate (p < 0.05) and a higher blood plasma concentration at 8 and 24 h after intraperitoneal injection compared with free IMC. In addition, decreased uptake of loaded IMC in the liver and kidney compared to free IMC (p < 0.05) was detected. Furthermore, PVP-OD4000 nanoparticles loaded with IMC showed an enhanced anti-inflammatory effect compared to free IMC (p < 0.05) in carrageenan-induced and complete Freund’s adjuvant-induced−(CFA) sub-chronic and chronic paw edema treatment (p < 0.01; p < 0.01). Notably, upon oral administration of loaded IMC, animals had a significantly lower ulcer score and Paul’s Index (3.9) compared to the free drug (p < 0.05). The obtained results suggest that IMC loaded to PVP nanoparticles exhibit superior anti-inflammatory activity in vivo and a safe gastrointestinal profile and pose a therapeutic alternative for the currently available NSAIDs’ administration.