Does the surface charge of the nanoparticles drive nanoparticle-cell membrane interactions?

Design of lipid-based formulations for oral delivery of a BASP1 peptide targeting MYC-dependent gastrointestinal cancer cells

HYPOTHESIS

Oral delivery of the proliferation-inhibiting brain acid-soluble protein 1 effector domain peptide (Myr-NT) towards MYC-dependent gastrointestinal tumors can be achieved by forming hydrophobic ion pairs (HIPs) and incorporating them into lipid-based formulations.

EXPERIMENTS

Hydrophobic ion pairing of fluorescently-labelled Myr-NT (Myr-NT-TAMRA) was performed, increase in lipophilicity was assessed, and the most promising HIP was subsequently incorporated into a nanoemulsion. Stability of the peptide towards degradation by trypsin was evaluated. Anti-proliferative and anti-invasive measurements were performed upon application of the loaded nanoemulsion on various MYC-dependent human cancer cell lines. Cellular uptake and molecular effect were complementary investigated by confocal laser scanning microscopy (CLSM) and by immunoblot analyses, respectively.

FINDINGS

HIPs of Myr-NT-TAMRA exhibited up to 10,000-fold increase in lipophilicity, thereby enabling incorporation into a nanoemulsion. The formulation significantly boosted stability of incorporated peptide towards enzymatic degradation by trypsin. Furthermore, anti-proliferative measurements on human cancer cell lines revealed superior biological activity of the loaded nanoemulsion compared to the native peptide particularly in lymphoma cells, but also in colorectal cancer cells. Thereby, a correlation with proliferation inhibition as well as differences in MYC protein expression were observed. Finally, CLSM imaging revealed up to 15-fold increased cellular uptake of Myr-NT-TAMRA from the nanoemulsion confirming efficient intracellular delivery of the peptide.

CONCLUSION

Myr-NT can be efficiently delivered into intestinal tumor cells using orally administered lipid-based formulations.

Photoaged polystyrene nanoplastics induce perturbation of glucose metabolism in HepG2 cells via oxidative stress

MICRO: & nano-plastics (MNPs) have been considered an emerging persistent pollutant in the environment. Most of the works focus on the potential toxicity of pristine, rather than photoaged, MNPs, let alone the underlying mechanisms of toxicity. To address this gap, we exposed human liver cancer cells (HepG2) to polystyrene nanoplastics (PS-NPs) with varying degrees of photodegradation, including pristine PS-NPs and photoaged PS-NPs irradiated with UV for 8 days (short-term) and 32 days (long-term).The surface characteristics of PS-NPs exhibited a significant alteration as characterized by SEM, FTIR, XPS, and Zetasizer. Exposure to PS-NPs affected cell viability, ion transport capacity and glucose metabolism, and also induced oxidative stress. Photoaged PS-NPs posed relatively higher impacts than pristine ones on HepG2 cells. Long-term photoaged PS-NPs induced the glucose metabolic disorders in a dose-dependent manner, while pristine and short-term photoaged PS-NPs induced the metabolic disorders only at high concentrations. The severe cellular metabolic toxicity of PS-NPs was attributed to the changes in physicochemical properties induced by UV irradiation, such as the production of oxygen-containing functional groups (hydroxyl, carboxyl, and carbonyl groups). Taken together, the long-term photoaged PS-NPs suppressed more than 10% of cell vitality compared to the pristine ones, and disrupted the glucose metabolism in HepG2 cells, particularly gene expression associated with glucose homeostasis.

The Toxicological Profile of Active Pharmaceutical Ingredients-Containing Nanoparticles: Classification, Mechanistic Pathways, and Health Implications

Nanotechnology is the manipulation of matter on an atomic and molecular scale, producing a lot of new substances with properties that are not necessarily easily expected based on present knowledge. Nanotechnology produces substances with unique properties that can be beneficial or harmful depending on their biocompatibility and distribution. Understanding nanomaterial toxicity is essential to ensure their safe application in biological and environmental applications. This review aims to provide a comprehensive overview of nanoparticle toxicity, focusing on their physicochemical properties, mechanisms of cellular uptake, and potential health risks. Key factors influencing toxicity include particle size, shape, concentration, aspect ratio, crystallinity, surface charge, dissolution, and agglomeration. Nanoparticles can induce oxidative stress and inflammation, contributing to adverse effects when inhaled, ingested, or applied to the skin. However, their toxicity may not be limited to just these pathways, as they can also exhibit other toxic properties, such as activation of the apoptotic pathway and mitochondrial damage. By summarizing the current knowledge on these aspects, this article intends to support the development of nanoparticles in a safer way for future applications.

Metal-organic framework nanoparticles activate cGAS-STING pathway to improve radiotherapy sensitivity

Tumor immunotherapy aims to harness the immune system to identify and eliminate cancer cells. However, its full potential is hindered by the immunosuppressive nature of tumors. Radiotherapy remains a key treatment modality for local tumor control and immunomodulation within the tumor microenvironment. Yet, the efficacy of radiotherapy is often limited by tumor radiosensitivity, and traditional radiosensitizers have shown limited effectiveness in hepatocellular carcinoma (HCC). To address these challenges, we developed a novel multifunctional nanoparticle system, ZIF-8@MnCO@DOX (ZMD), designed to enhance drug delivery to tumor tissues. In the tumor microenvironment, Zn²⁺ and Mn²⁺ ions released from ZMD participate in a Fenton-like reaction, generating reactive oxygen species (ROS) that promote tumor cell death and improve radiosensitivity. Additionally, the release of doxorubicin (DOX)-an anthracycline chemotherapeutic agent-induces DNA damage and apoptosis in cancer cells. The combined action of metal ions and double-stranded DNA (dsDNA) from damaged tumor cells synergistically activates the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway, thereby initiating a robust anti-tumor immune response. Both in vitro and in vivo experiments demonstrated that ZMD effectively activates the cGAS-STING pathway, promotes anti-tumor immune responses, and exerts a potent tumor-killing effect in combination with radiotherapy, leading to regression of both primary tumors and distant metastases. Our work provides a straightforward, safe, and effective strategy for combining immunotherapy with radiotherapy to treat advanced cancer.

Metallic nanoparticles: a promising novel therapeutic tool against antimicrobial resistance and spread of superbugs

In recent years, antimicrobial resistance (AMR) has become an alarming threat to global health as notable increase in morbidity and mortality has been ascribed to the emergence of superbugs. The increase in microbial resistance because of harboured or inherited resistomes has been complicated by the lack of new and effective antimicrobial agents, as well as misuse and failure of existing ones. These problems have generated severe and growing public health concern, due to high burden of bacterial infections resulting from scarce financial resources and poor functioning health systems, among others. It is therefore, highly pressing to search for novel and more efficacious alternatives for combating the action of these super bacteria and their infection. The application of metallic nanoparticles (MNPs) with their distinctive physical and chemical attributes appears as promising tools in fighting off these deadly superbugs. The simple, inexpensive and eco-friendly model for enhanced biologically inspired MNPs with exceptional antimicrobial effect and diverse mechanisms of action againsts multiple cell components seems to offer the most promising option and said to have enticed many researchers who now show tremendous interest. This synopsis offers critical discussion on application of MNPs as the foremost intervening strategy to curb the menace posed by the spread of superbugs. As such, this review explores how antimicrobial properties of the metallic nanoparticles which demonstrated considerable efficacy against several multi-drugs resistant bacteria, could be adopted as promising approach in subduing the threat of AMR and harvoc resulting from the spread of superbugs.

Dexamethasone-loaded chitosan-decorated PLGA nanoparticles: A step forward in attenuating the COVID-19 cytokine storm?

This study aims to develop and characterize poly (lactic-co-glycolic acid) (PLGA) nanoparticles decorated with chitosan (CS) for the encapsulation of dexamethasone (DEX) (NP-DEX-CS), targeting improved efficacy in the treatment of severe acute respiratory syndrome (SARS) associated with COVID-19. The nanoparticles were systematically characterized for size, zeta potential (ZP), morphology, encapsulation efficiency, and in vitro drug release. Incorporation of CS resulted in significant modifications in the nanoparticles' physical properties, notably an increase in size (from 207.3 ± 6.7 nm to 264.4 ± 4.4 nm) and a shift in ZP to positive values (from -11.8 ±1.4 mV to +30.0 ± 1,6 mV). The NP-DEX-CS formulation achieved a high encapsulation efficiency (∼79 %) and a drug loading capacity of 6.53 ± 0.02 %.In addition, the in vitro release rate of DEX from NP-DEX-CS was lower compared to undecorated nanoparticles, with a reduction from approximately 64-37 % within 24 h. Microscopy analyses revealed a smoother surface on the CS-decorated nanoparticles. FTIR and XRD analyses confirmed successful chitosan coating and DEX encapsulation. The CS coating enhanced the tolerability of J774.A1 cells to the nanoparticles, particularly evident at the highest concentration (400ug/mL), resulting in a cell viability ≥70 %. Importantly, the NP-DEX-CS significantly reduced levels of nitric oxide and inflammatory cytokines (IL-1, IL-6, IL-12, and TNF-α). These findings suggest that CS-decorated PLGA nanoparticles hold promise as an effective dexamethasone delivery system for treating SARS related to COVID-19.

Polymer Nano-Carrier-Mediated Gene Delivery: Visualizing and Quantifying DNA Encapsulation Using dSTORM

The success of gene therapy hinges on the effective encapsulation, protection, and compression of genes. These processes deliver therapeutic genes into designated cells for genetic repair, cellular behavior modification, or therapeutic effect induction. However, quantifying the encapsulation efficiency of small molecules of interest like DNA or RNA into delivery carriers remains challenging. This work shows how super-resolution microscopy, specifically direct stochastic optical reconstruction microscopy (dSTORM), can be employed to visualize and measure the quantity of DNA entering a single carrier. Utilizing pNIPAM/bPEI microgels as model nano-carriers to form polyplexes, DNA entry into the carrier is revealed across different charge ratios at temperatures below and above the volume phase transition of the microgel core. The encapsulation efficiency also depends on DNA length and shape. This work demonstrates the uptake of the carrier entity by primary derived macro-phages and showcases the cell viability of the polyplexes. The study shows that dSTORM is a potent tool for fine-tuning and creating polyplex microgel carrier systems with precise size, shape, and loading capacity at the individual particle level. This advancement shall contribute significantly to optimizing gene delivery systems.

Tadpole-like cationic single-chain nanoparticles display high cellular uptake

The successful delivery of nanoparticles (NPs) to cancer cells is dependent on various factors, including particle size, shape, surface properties such as hydrophobicity/hydrophilicity, charges, and functional moieties. Tailoring these properties has been explored extensively to enhance the efficacy of NPs for drug delivery. Single-chain polymer nanoparticles (SCNPs), notable for their small size (sub-20 nm) and tunable properties, are emerging as a promising platform for drug delivery. However, the impact of surface charge on the biological performance of SCNPs in cancer cells remains underexplored. In this study, we prepared a library of SCNPs with varying charge types (neutral, anionic, cationic, and zwitterionic), charge densities, charge positions, and crosslinking densities to evaluate their effects on cellular uptake in MCF-7 breast cancer cells. Key findings include that cationic SCNPs are more likely to translocate into cells than neutral, anionic, or zwitterionic counterparts. Furthermore, cellular uptake was enhanced with increased charge density (from 10 to 15 mol%) before reaching a critical point (20 mol%) where excessive positive charge led to NP adhesion to the cell membrane, resulting in cell death. We also found that the position of the charge on the polymer chain also impacted the delivery of NPs to cancer cells, with tadpole-shaped SCNPs achieving the highest uptake. Furthermore, crosslinking density significantly influenced cellular uptake, with SCNPs at 50% crosslinking conversion showing the highest cytosolic localization, while other densities resulted in retention primarily at the cell membrane. This study offers valuable insights into how charge type, density, position, and crosslinking density affect the biological performance of SCNPs, guiding the rational design of more effective and safer drug delivery systems.

Glycocalyx Interactions Modulate the Cellular Uptake of Albumin-Coated Nanoparticles

Albumin-based nanoparticles (ABNPs) represent promising drug carriers in nanomedicine due to their versatility and biocompatibility, but optimizing their effectiveness in drug delivery requires understanding their interactions with and uptake by cells. Notably, albumin interacts with the cellular glycocalyx, a phenomenon particularly studied in endothelial cells. This observation suggests that the glycocalyx could modulate ABNP uptake and therapeutic efficacy, although this possibility remains unrecognized. In this study, we elucidate the critical role of the glycocalyx in the cellular uptake of a model ABNP system consisting of silica nanoparticles (NPs) coated with native, cationic, and anionic albumin variants (BSA, BSA+, and BSA-). Using various methodologies-including fluorescence anisotropy, dynamic light scattering, microscale thermophoresis, surface plasmon resonance spectroscopy, and computer simulations─we found that both BSA and BSA+, but not BSA-, interact with heparin, a model glycosaminoglycan (GAG). To explore the influence of albumin-GAG interactions on NP uptake, we performed comparative uptake studies in wild-type and GAG-mutated Chinese hamster ovary cells (CHO), along with complementary approaches such as enzymatic GAG cleavage in wild-type cells, chemical inhibition, and competition assays with exogenous heparin. We found that the glycocalyx enhances the cell uptake of NPs coated with BSA and BSA+, while serving as a barrier to the uptake of NPs coated with BSA-. Furthermore, we showed that harnessing albumin-GAG interactions increases cancer cell death induced by paclitaxel-loaded albumin-coated NPs. These findings underscore the importance of albumin-glycocalyx interactions in the rational design and optimization of albumin-based drug delivery systems.

Design Principles for Smart Linear Polymer Ligand Carriers with Efficient Transcellular Transport Capabilities

The surface functionalization of polymer-mediated drug/gene delivery holds immense potential for disease therapy. However, the design principles underlying the surface functionalization of polymers remain elusive. In this study, we employed computer simulations to demonstrate how the stiffness, length, density, and distribution of polymer ligands influence their penetration ability across the cell membrane. Our simulations revealed that the stiffness of polymer ligands affects their ability to transport cargo across the membrane. Increasing the stiffness of polymer ligands can promote their delivery across the membrane, particularly for larger cargoes. Furthermore, appropriately increasing the length of polymer ligands can be more conducive to assisting cargo to enter the lower layer of the membrane. Additionally, the distribution of polymer ligands on the surface of the cargo also plays a crucial role in its transport. Specifically, the one-fourth mode and stripy mode distributions of polymer ligands exhibited higher penetration ability, assisting cargoes in penetrating the membrane. These findings provide biomimetic inspiration for designing high-efficiency functionalization polymer ligands for drug/gene delivery.