Hyper-Branched Cationic Cyclodextrin Polymers for Improving Plasmid Transfection in 2D and 3D Spheroid Cells

β-Cyclodextrin nanosponges for the ocular delivery of therapeutic Micro-RNA in a Mouse model of retinitis Pigmentosa: A proof of concept study

The exploitation of micro-RNA (miR) sequences as therapeutics has become highly attractive for the treatment of several diseases, including those still lacking effective cures such as retinitis pigmentosa (RP). Interestingly, miR-155-5p plays a role in photo-oxidative inflammation in wild-type mice and is up-regulated in rd10 mice showing peak rod degeneration, suggesting its inhibition by the corresponding anti-miR as a viable therapeutic strategy for RP. However, biomedical application of (anti-)miRs is limited by their oligonucleotide nature, suffering from low solubility and bioavailability along with a very low half-life in vivo due to enzymatic degradation. Thereby, the need for suitable delivery systems led to the development of various nanocarriers, including oligosaccharide-based polymers. In this context, we designed and prepared an innovative nanosponge (NS) with a β-cyclodextrin (β-CD) motif payload with a bridge-like molecule, the amphipathic adamantane derivative (ADM), able to establish strong interactions with both NS and the therapeutic miR, thereby delivering and eventually releasing it close to the active site. Through an in vivo study, we both validated the NS system as a useful tool for miR topical administration by eye drop formulation and the functional activity of anti-miR-155-5p in RP.

Multifunctional Polypeptide-Based Nanoconjugates for Targeted Mitochondrial Delivery and Nonviral Gene Therapy

Despite recent advances in nanomedicine, developing multifunctional nanocarriers capable of targeted subcellular delivery and efficient gene therapy remains a significant challenge. This study reports the design, synthesis, and evaluation of a novel multifunctional polypeptide-based nanoconjugate that addresses this gap using sequential delivery, combining mitochondrial targeting and nonviral gene therapy. We engineered a poly-l-ornithine-based, polyethylene glycol-modified carrier and introduced a novel custom-designed trivalent compound (TRV3) into the structure. TRV3, conjugated to the polypeptide carrier via a redox-sensitive disulfide linker, incorporates the well-described triphenylphosphonium moiety (TPP) for mitochondrial targeting and a Cy5 fluorophore as a model drug. The resulting nanoconjugate (C-TRV3-A) demonstrated efficient endosomal escape and mitochondrial localization. Leveraging the endosomolytic properties of C-TRV3-A, we explored its potential as a nonviral vector for gene therapy. After optimizing formulation stability using a VLC-3 anionic polypeptide coating, we developed plasmid DNA polyplexes that exhibited enhanced stability and transfection efficiency in basic and advanced triple-negative breast cancer cell culture models. This multifunctional polypeptide-based nanoconjugate represents a significant advance in the field, offering a chemically versatile platform for simultaneous subcellular targeting and gene delivery that may be used in targeted cancer treatments, among other pathologies.

Modulating exosomal communication between macrophages and melanoma cancer cells via cyclodextrin-based nanosponges loaded with doxorubicin

The cellular components of the tumor microenvironment (TME) comprise cancer cells and nonmalignant cells including stromal and immune cells. Exosomes are extracellular vesicles secreted by various types of cells that play a crucial role in intercellular communications within TME. The main goal of this study was to elucidate how exosomes of macrophage cells treated with doxorubicin (DOX) and DOX-loaded cyclodextrin-based nanosponges (DOX-CDNSs), affect melanoma cancer cell proliferation. For this aim, the exosomes of the murine macrophage cell line (RAW 264.7) were isolated and characterized after treating the cells with DOX and DOX-CDNSs. The results demonstrated that DOX-CDNSs at a treatment concentration of 1 µg/mL, were nontoxic for macrophages and remarkably toxic against cancer cells. However, DOX was nontoxic for both cell types at the same treatment concentration. DOX and DOX-CDNSs remarkably declined the viability of both cell types at higher concentrations (25 and 50 µg/mL). Intriguingly, the exosomes of DOX-CD-NSs treated macrophages promoted the viability of cancer cells at the treatment concentrations of 1, 20, and 40 µg/mL. While the exosomes of DOX-treated macrophages increased cell viability of cancer cells only at the lowest concentration. In conclusion, this study suggests that utilization of CD-NSs may augment the toxicity of DOX against cancer cells, while it could direct macrophages toward secreting exosomes that favor the growth of cancer cells.

Cationic Cyclodextrin-Based Carriers for Drug and Nucleic Acid Delivery

Cyclodextrins can serve as carriers for various payloads, utilizing their capacity to form unique host-guest inclusion complexes within their cavity and their versatile surface functionalization. Recently, cationic cyclodextrins have gained considerable attention, as they can improve drug permeability across negatively charged cell membranes and efficiently condense negatively charged nucleic acid due to electrostatic interactions. This review focuses on state-of-the-art and recent advances in the construction of cationic cyclodextrin-based delivery systems. First, we identified different cationic moieties that are commonly employed in the design of cyclodextrins with enhanced complexation ability. Subsequently, a wide range of cationic cyclodextrin-based drug delivery systems were analyzed with emphasis on chemistry, drug release profiles, and therapeutic outcomes. The evaluation of the delivery platforms was also based on the four major types of drugs, such as anticancer, anti-inflammatory, antibacterial, and antidiabetic agents. The delivery systems for nucleic acids were also summarized while focusing on their condensation ability, transfection efficiency, and biocompatibility in comparison to commercially available vectors such as PEI 25 kDa and lipofectamine 2000. Furthermore, we highlighted the potential of cationic cyclodextrins in constructing multimodal delivery systems for the simultaneous encapsulation of both drugs and nucleic acids. Finally, the challenges and limitations associated with cationic cyclodextrin setups were discussed.

Delineating effect of headgroup and preparation method on transfection versus toxicity of DNA-loaded lipid nanocarriers

Aim: To perform a parallel comparison of key parameters affecting the safety and efficiency of lipid-based nanovectors (i.e., complexing headgroups, composition and preparation method). Materials & methods: Various cationic and ionizable headgroups were screened for formulating lipoplexes with GFP-plasmid DNA. Ethanol injection and microfluidics were used to prepare nanoparticles with GFP-plasmid DNA complexed on the surface or within the interior of lipid bilayers. Results: Lipoplexes composed of sphingomyelin 102 exhibited the highest transfection efficiency given their higher cellular uptake in BRAF inhibitor-resistant melanoma cells. Lipid nanoparticles demonstrated acceptable transfection efficiency and high spheroid penetration while protecting plasmid DNA under simulated physiological conditions. Conclusion: Selecting the right complexing lipid and preparation method is critical for developing lipid nanocarriers to treat intractable diseases.

Harnessing graphene oxide nanocarriers for siRNA delivery in a 3D spheroid model of lung cancer

Gene therapy has been recently proposed as an effective strategy for cancer treatment. A significant body of literature proved the effectiveness of nanocarriers to deliver therapeutic agents to 2D tumour models, which are simple but not always representative of the in vivo reality. In this study, we analyze the efficiency of 3D spheroids combined with a minimally modified graphene oxide (GO)-based nanocarrier for siRNA delivery as a new system for cell transfection. Small interfering RNA (siRNA) targeting cluster of differentiation 47 (CD47; CD47_siRNA) was used as an anti-tumour therapeutic agent to silence the genes expressing CD47. This is a surface marker able to send a "don't eat me" signal to macrophages to prevent their phagocytosis. Also, we report the analysis of different GO formulations, in terms of size (small: about 100 nm; large: >650 nm) and functionalization (unmodified or modified with polyethylene glycol (PEG) and the dendrimer PAMAM), aiming to establish the efficiency of unmodified GO as a nanocarrier for the transfection of A549 lung cancer spheroids. Small modified GO (smGO) showed the highest transfection efficiency values (>90%) in 3D models. Interestingly, small unmodified GO (sGO) was found to be promising for transfection, with efficiency values >80% using a higher siRNA ratio (i.e., 3 : 1). These results demonstrated the higher efficiency of spheroids compared to 2D models for transfection, and the high potential of unmodified GO to carry siRNA, providing a promising new in vitro model system for the analysis of anticancer gene therapies.

Polyester urethane urea (PEUU) functionalization for enhanced anti-thrombotic performance: advancing regenerative cardiovascular devices through innovative surface modifications

Introduction: Thrombogenesis, a major cause of implantable cardiovascular device failure, can be addressed through the use of biodegradable polymers modified with anticoagulating moieties. This study introduces a novel polyester urethane urea (PEUU) functionalized with various anti-platelet deposition molecules for enhanced antiplatelet performance in regenerative cardiovascular devices. Methods: PEUU, synthesized from poly-caprolactone, 1,4-diisocyanatobutane, and putrescine, was chemically oxidized to introduce carboxyl groups, creating PEUU-COOH. This polymer was functionalized in situ with polyethyleneimine, 4-arm polyethylene glycol, seleno-L-cystine, heparin sodium, and fondaparinux. Functionalization was confirmed using Fourier-transformed infrared spectroscopy and X-ray photoelectron spectroscopy. Bio-compatibility and hemocompatibility were validated through metabolic activity and hemolysis assays. The anti-thrombotic activity was assessed using platelet aggregation, lactate dehydrogenase activation assays, and scanning electron microscopy surface imaging. The whole-blood clotting time quantification assay was employed to evaluate anticoagulation properties. Results: Results demonstrated high biocompatibility and hemocompatibility, with the most potent anti-thrombotic activity observed on pegylated surfaces. However, seleno-L-cystine and fondaparinux exhibited no anti-platelet activity. Discussion: The findings highlight the importance of balancing various factors and addressing challenges associated with different approaches when developing innovative surface modifications for cardiovascular devices.

Intratumoural Delivery of mRNA Loaded on a Cationic Hyper-Branched Cyclodextrin-Based Polymer Induced an Anti-Tumour Immunological Response in Melanoma

mRNA technology has demonstrated potential for use as an effective cancer immunotherapy. However, inefficient in vivo mRNA delivery and the requirements for immune co-stimulation present major hurdles to achieving anti-tumour therapeutic efficacy. Therefore, we used a cationic hyper-branched cyclodextrin-based polymer to increase mRNA delivery in both in vitro and in vivo melanoma cancer. We found that the transfection efficacy of the mRNA-EGFP-loaded Ppoly system was significantly higher than that of lipofectamine and free mRNA in both 2D and 3D melanoma cancer cells; also, this delivery system did not show cytotoxicity. In addition, the biodistribution results revealed time-dependent and significantly higher mEGFP expression in complexes with Ppoly compared to free mRNA. We then checked the anti-tumour effect of intratumourally injected free mRNA-OVA, a foreign antigen, and loaded Ppoly; the results showed a considerable decrease in both tumour size and weight in the group treated with OVA-mRNA in loaded Ppoly compared to other formulations with an efficient adaptive immune response by dramatically increasing most leukocyte subtypes and OVA-specific CD8+ T cells in both the spleen and tumour tissues. Collectively, our findings suggest that the local delivery of cationic cyclodextrin-based polymer complexes containing foreign mRNA antigens might be a good and reliable concept for cancer immunotherapy.

The Role of Cyclodextrin in the Construction of Nanoplatforms: From Structure, Function and Application Perspectives

Cyclodextrins (CyDs) in nano drug delivery systems have received much attention in pursuit of good compatibility, negligible toxicity, and improved pharmacokinetics of drugs. Their unique internal cavity has widened the application of CyDs in drug delivery based on its advantages. Besides this, the polyhydroxy structure has further extended the functions of CyDs by inter- and intramolecular interactions and chemical modification. Furthermore, the versatile functions of the complex contribute to alteration of the physicochemical characteristics of the drugs, significant therapeutic promise, a stimulus-responsive switch, a self-assembly capability, and fiber formation. This review attempts to list recent interesting strategies regarding CyDs and discusses their roles in nanoplatforms, and may act as a guideline for developing novel nanoplatforms. Future perspectives on the construction of CyD-based nanoplatforms are also discussed at the end of this review, which may provide possible direction for the construction of more rational and cost-effective delivery vehicles.