Biodegradable and Dual-Responsive Polypeptide-Shelled Cyclodextrin-Containers for Intracellular Delivery of Membrane-Impermeable Cargo

Nanocarriers for intracellular delivery of molecular payloads triggered by visible light

Stimuli-responsive nanocontainers have emerged as promising vehicles to deliver molecular payloads into the cytosol of cells in a spatially, temporally and dosage-controlled manner. These nanocontainers respond to a specific type of stimulus such as a change in redox status, enzymatic activity, pH, heat, light, and others. In this work, we introduce photoresponsive nanocontainers based on the self-assembly of vesicles with surface-confined cyclodextrin-adamantane host-guest chemistry. The nanocontainer surface is protected by a polymer shell with a tetrazine cross-linker that enables triggered delivery of payloads upon exposure to green light (515 nm). We show that the release of vesicle-encapsulated payload is achieved also in cells by visible light, which is less harmful than the UV-light responsive release reported previously for in vitro systems.

Interfacial Denaturation at the Droplet Simplifies the Formation of Drug-Loaded Protein Nanocapsules to Enhance Immune Response of Cells

Nanocapsules enable multicomponent encapsulation of therapeutic cargoes with high encapsulation content and efficiency, which is vital for cancer immunotherapy. In the past, chemical crosslinking is used to synthesize nanocapsules, which can impede the regulatory approval process. Therefore, a new class of protein nanocapsules is developed by eliminating the need for chemical crosslinking by utilizing protein denaturation through a process that is referred to as "baking at the droplet interface". Such protein nanocapsules with antigens incorporated in the shell and a combination of encapsulated drugs showed an enhancement in the immune response of cells.

The Many Faces of Cyclodextrins within Self-Assembling Polymer Nanovehicles: From Inclusion Complexes to Valuable Structural and Functional Elements

Most chemotherapeutic agents are poorly soluble in water, have low selectivity, and cannot reach the tumor in the desired therapeutic concentration. On the other hand, sensitive hydrophilic therapeutics like nucleic acids and proteins suffer from poor bioavailability and cell internalization. To solve this problem, new types of controlled release systems based on nano-sized self-assemblies of cyclodextrins able to control the speed, timing, and location of therapeutic release are being developed. Cyclodextrins are macrocyclic oligosaccharides characterized by a high synthetic plasticity and potential for derivatization. Introduction of new hydrophobic and/or hydrophilic domains and/or formation of nano-assemblies with therapeutic load extends the use of CDs beyond the tried-and-tested CD-drug host-guest inclusion complexes. The recent advances in nano drug delivery have indicated the benefits of the hybrid amphiphilic CD nanosystems over individual CD and polymer components. This review provides a comprehensive overview of the most recent advances in the design of CDs self-assemblies and their use for delivery of a wide range of therapeutic molecules. It aims to offer a valuable insight into the many roles of CDs within this class of drug nanocarriers as well as current challenges and future perspectives.

Rosmarinic Acid-Crosslinked Supramolecular Nanoassembly with Self-Regulated Photodynamic and Anti-Metastasis Properties for Synergistic Photoimmunotherapy

A primary concern about photodynamic therapy (PDT) is its inability to regulate the generation levels of reactive oxidative species (ROS) based on the complex microenvironment, resulting in the impairment toward normal tissues and immunosuppression. Besides, tumor metastasis also compromises PDT's efficacy and drives mortality. However, it is very challenging to achieve such two goals within one nanosystem. Here, the nanoassembly (CPR) with self-regulated photodynamic and antimetastasis properties comprises three parts: chlorin e6-conjugated β-cyclodextrin (CD-Ce6) acts as the main PDT agent and ferrocene (Fc)-terminated phenylboronic acid-containing conjugates entering into the cavity of CD-Ce6, as well as rosmarinic acid (RA)-boronic acid crosslinked shell. Compared with non-crosslinked counterpart, CPR displays better stability and enhanced tumor accumulation. Under laser irradiation, CPR generates plenty of ROS to damage tumor cells and induce immunogenic cell death. Mildly acidic TME partly cleaves the crosslinkers to dissociate antioxidant RAs from micelles, which together with Fc in CPR scavenge PDT-induced ROS in the TME. By contrast, under acidic lysosomal conditions, Fc catalyzes abundant H₂ O₂ in tumor cells to produce highly cytotoxic •OH, while RA continuously reduces ferroptosis-generated Fc⁺ into Fc, both to augment the PDT efficacy in tumor cells. CPR also remarkably hinders the epithelial-mesenchymal transition to prevent the lung metastasis.

Ensembles of carboxymethyl cyclodextrins on cationic liposomes as highly efficient nanocontainers for the delivery of hydrophobic compounds

The increase of payload is one of the key tasks in creation of nanocontainers for the delivery of bioactive substances (BAS). In this work the adsorption of anionic carboxymethyl cyclodextrins (CMCDs) on the surface of cationic liposomes was studied as mechanism of formation of capacious nanocontainers for the encapsulation and delivery of hydrophobic BAS. The formation and physico-chemical characteristics of complexes were studied by means of laser microelectrophoresis, dynamic light-scattering, conductometry and atomic force microscopy (AFM). As a model, bioactive molecule hydrophobic curcumin was chosen for the investigation. The encapsulation of curcumin was controlled by UV-Vis spectrometry. Interaction of CMCDs/liposomes complexes with model cell membranes was visualized by fluorescent microscopy. Finally, cytotoxicity of nanocontainers was studied by MTT-test. It was estimated that colloid stable complexes with net positive charge could contain up to 2.5÷5 CMCD molecules per one cationic lipid. Incorporation of curcumin in CMCDs does not change the character of interaction of oligosaccharides with liposomal membranes of individual liposome. CMCDs/liposomes complexes adsorb on model cell membranes without significant loss of CMCD molecules. This fact in addition to low cytotoxicity of cationic CMCDs/liposomes complexes demonstrates potential of their application as nanovehicles for the delivery of BAS.

High-Throughput and Efficient Intracellular Delivery Method via a Vibration-Assisted Nanoneedle/Microfluidic Composite System

Intracellular delivery and genetic modification have brought a significant revolutionary to tumor immunotherapy, yet existing methods are still limited by low delivery efficiency, poor throughput, excessive cell damage, or unsuitability for suspension immune cells, specifically the natural killer cell, which is highly resistant to transfection. Here, we proposed a vibration-assisted nanoneedle/microfluidic composite system that uses large-area nanoneedles to rapidly puncture and detach the fast-moving suspension cells in the microchannel under vibration to achieve continuous high-throughput intracellular delivery. The nanoneedle arrays fabricated based on the large-area self-assembly technique and microchannels can maximize the delivery efficiency. Cas9 ribonucleoprotein complexes (Cas9/RNPs) can be delivered directly into cells due to the sufficient cellular membrane nanoperforation size; for difficult-to-transfect immune cells, the delivery efficiency can be up to 98%, while the cell viability remains at about 80%. Moreover, the throughput is demonstrated to maintain a mL/min level, which is significantly higher than that of conventional delivery techniques. Further, we prepared CD96 knockout NK-92 cells via this platform, and the gene-edited NK-92 cells possessed higher immunity by reversing exhaustion. The high-throughput, high-efficiency, and low-damage performance of our intracellular delivery strategy has great potential for cellular immunotherapy in clinical applications.

Photothermally Triggered Melting and Perfusion: Responsive Colloidosomes for Cytosolic Delivery of Membrane-Impermeable Drugs in Tumor Therapy

Cell membrane barrier which dominates the therapeutic efficacy and systemic side effects is a major bottleneck in the field of drug delivery. Herein, a therapeutic system capable of photothermally triggered...

Redox/pH-Responsive 2-in-1 Chimeric Nanoparticles for the Co-Delivery of Doxorubicin and siRNA

The co-delivery of chemotherapy drugs and gene-suppressing small interfering RNA (siRNA) show promise for cancer therapy. The key to the clinical realization of this treatment model will be the development of a carrier system enabling the simultaneous delivery (“co-delivery” instead of combinatorial delivery) of chemotherapy and siRNA agents to cancer. In this study, a co-delivery system was developed from two individual components to form one integrated nanovehicle through a redox-sensitive thiol–disulfide bond for the synergistic delivery of chemotherapy and RNA silencing: doxorubicin (Dox)-loaded N,O-carboxymethyl chitosan (NOCC) complex with a thiolated hyaluronic acid (HA-SH) nanocarrier and dopamine (Dopa)-conjugated thiolated hyaluronic acid (SH-HA-Dopa)-coated calcium phosphate (CaP)-siRNA nanocarrier. The 2-in-1 chimeric nanoparticles (NPs) were structurally stable together in the storage environment and in the circulation. This smart system selectively releases Dox and siRNA into the cytosol. Furthermore, equipped with the tumor-targeting component HA, the co-delivery system shows specific targeting and high cellular uptake efficiency by receptor-mediated endocytosis. In summary, these dual-responsive (redox and pH), tumor-targeting smart 2-in-1 chimeric NPs show promise to be employed in functional co-delivery and tumor therapy.