Magnetically-stimulated transformations in the nanostructure of PEGylated phytantriol-based nanoparticles for on-demand drug release

Cubosomes functionalized with antibodies as a potential strategy for the treatment of HER2-positive breast cancer

Breast cancers that overexpress human epidermal growth factor receptor 2 (HER2) have poor prognosis. Moreover, available chemotherapies cause numerous side effects due to poor selectivity. To advance more effective and safer therapies for HER2-positive breast cancer, we explored the fusion of drug delivery technology and immunotherapy. Our research led to the design of immunocubosomes loaded with panobinostat and functionalized with trastuzumab antibodies, enabling precise targeting of breast cancer cells that overexpress HER2. We characterised the nanostructure of cubosomes using small-angle X-ray scattering (SAXS), cryo-transmission electron microscopy (cryo-TEM), and dynamic light scattering (DLS). Moreover, we confirmed the integrity of the trastuzumab antibodies on the immunocubosomes by Fourier-transform infrared spectroscopy (FTIR) and sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Additionally, we found that panobinostat-loaded immunocubosomes were more cytotoxic, and in an uptake-dependant manner, towards a HER2-positive breast cancer cell line (SKBR3) compared to a cell line representing healthy cells (L929). These results support that the functionalization of cubosomes with antibodies enhances both the effectiveness of the loaded drug and its selectivity for targeting HER2-positive breast cancer cells.

pH-Dependent Lyotropic Liquid Crystalline Mesophase and Ionization Behavior of Phytantriol-Based Ionizable Lipid Nanoparticles

Self-assembled lipid nanoparticles (LNPs), serving as essential nanocarriers in recent COVID-19 mRNA vaccines, provide a stable and versatile platform for delivering a wide range of biological materials. Notably, LNPs with unique inverse mesostructures, such as cubosomes and hexosomes, are recognized as fusogenic nanocarriers in the drug delivery field. This study delves into the physicochemical properties, including size, lyotropic liquid crystalline mesophase, and apparent pKa of LNPs with various lipid components, consisting of two ionizable lipids (ALC-0315 and SM-102) used in commercial COVID-19 mRNA vaccines and a well-known inverse mesophase structure-forming helper lipid, phytantriol (PT). Two partial mesophase diagrams are generated for both ALC-0315/PT LNPs and SM-102/PT LNPs as a function of two factors, ionizable lipid ratio (α, 0-100 mol%) and pH condition (pH 3-11). Furthermore, the impact of different LNP stabilizers (Pluronic F127, Pluronic F108, and Tween 80) on their pH-dependent phase behavior is evaluated. The findings offer insights into the self-assembled mesostructure and ionization state of the studied LNPs with potentially enhanced endosomal escape ability. This research is relevant to developing innovative next-generation LNP systems for delivering various therapeutics.

Interaction of polyelectrolyte-shell cubosomes with serum albumin for triggering drug release in gastrointestinal cancer

Nano-structured and functionalized materials for encapsulation, transport, targeting and controlled release of drugs are of high interest to overcome low bioavailability in oral administration. We develop lipid-based cubosomes, which are surface-functionalized with biocompatible chitosan-N-arginine and alginate, displaying internal liquid crystalline structures. Polyelectrolyte-shell (PS) cubosomes have pH-responsive characteristics profitable for oral delivery. The obtained PScubosomes can strongly interact with serum albumin, a protein which is released in the stomach under gastric cancer conditions. An effective thermodynamic PScubosome-protein interaction was characterized at pH 2.0 and 7.4 by isothermal titration calorimetry at 37 °C. A high increment of the albumin conformation transition temperature was evidenced by differential scanning calorimetry upon incubation with PScubosomes. The performed structural studies by synchrotron small-angle X-ray scattering (SAXS) revealed essential alterations in the internal liquid crystalline topology of the nanocarriers including an Im3m to Pn3m transition and a reduction of the cubic lattice parameters. The PScubosome nanoparticle interaction with serum albumin, leading to inner structural changes in a range of temperatures, promoted the release of water from the cubosomal nanochannels. Altogether, the results revealed effective interactions of the PScubosomes with albumin under simulated gastrointestinal pH conditions and suggested promising nanocarrier characteristics for triggered oral drug release.

Enhancing the photoluminescence and cellular uptake of fluorescent carbon nanodots via cubosome lipid nanocarriers

Carbon nanodots (C-dots) have attracted much attention for their use in the fields of bioimaging, drug delivery, and sensing due to their excellent fluorescent and photoluminescent properties, photostability, biocompatibility, and amenability to surface modification. Herein, we report a nanocomposite formulation of C-dots (<5 nm) encapsulated in lipid-based lyotropic liquid crystalline nanoparticles (∼250 nm) via either passive diffusion or electrostatic mechanisms. The physicochemical properties of the nanocomposite formulation including particle size, surface charge, internal cubic nanostructures, and pH-dependent fluorescent properties were characterised. Upon loading of C-dots into lipid nanoparticles, the highly ordered inverse bicontinuous cubic mesophase existed in the internal phase of the nanoparticles, demonstrated by synchrotron small angle X-ray scattering, molecular dynamic simulation and cryogenic transmission electron microscopy. The pH-dependent fluorescent property of the C-dots was modified via electrostatic interaction between the C-dots and cationic lipid nanoparticles, which further enhanced the brightness of C-dots through self-quenching prevention. The cytotoxicity and cellular uptake efficiency of the developed nanocomposites were also examined in an epithelial gastric adenocarcinoma cell line (AGS) and a macrophage cell line (stimulated THP-1). Compared to free C-dots, the uptake and cell imaging potential of the C-dot nanocomposites was significantly improved, by several orders of magnitude as demonstrated by cytoplasmic fluorescent intensities using confocal microscopy. Loading C-dots into mesoporous lipid nanocarriers presents a new way of modifying C-dot physicochemical and fluorescent properties, alternative to direct chemical surface modification, and advances the bioimaging potential of C-dots by enhancing cellular uptake efficiency and converging C-dot light emission.

Magnetically‐activated lipid nanocarriers in biomedical applications: A review of current status and perspective

Magnetically-activated lipid nanocarriers have become a research hotspot in the field of biomedicine. Liposomes and other lipid-based carriers possess good biocompatibility as well as the ability to carrying therapeutic cargo with a range of physicochemical properties. Previous studies have demonstrated that magnetic materials have potential wide applications in clinical diagnosis and therapy, such as in MRI as contrast agents and in hyperthermic obliteration of cancer tissues. More recently magneto-thermal activation of lipid carriers to stimulate drug release has extended the range of further therapeutic benefits. Here, an overview of the current development of magnetically-activated lipid nanocarriers in the field of biomedicine is provided, including the methods of fabrication of the nanocarriers and their in vitro and in vivo performance. A discussion of the current barriers to translation of these materials as medicines is provided in the context of clinical and regulatory complexities of using magnetically responsive materials in therapeutic applications. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Biology-Inspired Nanomaterials > Lipid-Based Structures Implantable Materials and Surgical Technologies > Nanomaterials and Implants.

Precision Nanomedicines: Targeting Hot Mitochondria in Cancer Cells

Mitochondrion is a multifunctional organelle in a cell, and it is one of the important targets of antitumor therapy. Conventional mitochondrial targeting strategies can hardly distinguish the mitochondria in cancer cells from those in normal cells, which might raise a concern about the biosafety. Recent studies suggest that a relatively high temperature of mitochondria exists in cancer cells. We named it tumor intrinsic mitochondrial overheating (TIMO). By taking advantage of the difference in mitochondrial temperatures between cancer cells and normal cells, therapeutic agents can be specifically delivered to the mitochondria in cancer cells. Here we will briefly overview the mitochondria-targeted delivery strategies. In addition, the recent discovery of hot mitochondria in cancer cells and the development of mitochondrial temperature-responsive delivery systems for antitumor therapy will be reviewed.

Thiol-responsive lyotropic liquid crystals exhibit triggered phase re-arrangement and hydrogen sulfide (H2S) release

Hydrogen sulfide (H₂S) is an important signalling molecule with potential pharmaceutical applications. In pursuit of a suitable delivery system for H₂S, herein we apply an amphiphilic trisulfide to concomitantly alter the mesophase behaviour of dispersed lipid particles and enable triggered H₂S release. Amperometric release studies indicate the trisulfide acts as a sustained H₂S donor, with inclusion into the mesophase attenuating release vs neat dispersed trisulfide. Taken together the results highlight the potential for including trisulfide-based additives in stimuli-responsive drug delivery vehicles.