Biological Effect Evaluation of Glutathione-Responsive Cyclodextrin-Based Nanosponges: 2D and 3D Studies

Cyclodextrin based nanoparticles for smart drug delivery in colorectal cancer

The advancement of colorectal cancer (CRC) prevention, detection, and treatment is essential to ensure that survivors live longer and higher-quality lives. The field of cancer detection and therapy has undergone a revolution with the development of nanotechnology for targeted drug delivery. The significant problems with the delivery of cancer drugs are their solubility, stability, and nonspecific distribution. There is a challenge that the acidic and enzymatic environment in the digestive tract will modify or destroy the medication or the active pharmaceutical ingredient. To overcome the problems, nanoparticles have been widely employed during the past several years to increase the specificity, selectivity, and controlled release of drug delivery systems. The site-specific and targeted delivery leads to reduce toxicity and side effects. With respect to the capability and utilization of cyclodextrin-based nanoparticles in different aspects of the tumour microenvironment and gut microbiota, a survey of current research papers was conducted via looking through databases including GoogleScholar, PubMed, Web of Science, and Scopus. This review aims to summarize cutting-edge nanoparticulate-based technologies and therapies for CRC.

Bioresponsive and multifunctional cyclodextrin-based non-viral nanocomplexes in cancer therapy: Building foundations for gene and drug delivery, immunotherapy and bioimaging

The interest towards application of nanomaterials in field of cancer therapy is that the drawbacks of conventional therapies including chemoresistance, radio-resistance and lack of specific targeting of tumor cells can be solved by nanotechnology. Cyclodextrins (CDs) are amphiphilic cyclic oligosaccharides that can be present in three forms of α-, β- and γ-CDs, and they can be synthesized from natural sources. The application of CDs in cancer shows an increasing trend due to benefits of these nanocomplexes in improving solubility and bioavailability of current bioactives and therapeutics for cancer. CDs are widely utilized in delivery of drugs and genes in cancer therapy, and by targeted delivery of these therapeutics into target site, they improve anti-proliferative and anti-cancer potential. The blood circulation time and tumor site accumulation of therapeutics can be improved using CD-based nanostructures. More importantly, the stimuli-responsive types of CDs including pH-, redox- and light-sensitive types can accelerate release of bioactive compound at tumor site. Interestingly, the CDs are able to mediate photothermal and photodynamic impact in impairing tumorigenesis in cancer, enhancing cell death and improving response to chemotherapy. In improving the targeting ability of CDs, their surface functionalization with ligands has been conducted. Moreover, CDs can be modified with green products such as chitosan and fucoidan, and they can be embedded in green-based nanostructures to suppress tumorigenesis. The internalization of CDs into tumor cells can occur through endocytosis and this can be clethrin-, caveolae- or receptor-mediated endocytosis. Furthermore, CDs are promising candidates in bioimaging, cancer cell and organelle imaging as well as isolating tumor cells. The main benefits of using CDs in cancer therapy including sustained and low release of drugs and genes, targeted delivery, bioresponsive release of cargo, ease of surface functionalization and complexation with other nanostructures. The application of CDs in overcoming drug resistance requires more investigation.

Nano-Enabled Antivirals for Overcoming Antibody Escaped Mutations Based SARS-CoV-2 Waves

This review discusses receptor-binding domain (RBD) mutations related to the emergence of various SARS-CoV-2 variants, which have been highlighted as a major cause of repetitive clinical waves of COVID-19. Our perusal of the literature reveals that most variants were able to escape neutralizing antibodies developed after immunization or natural exposure, pointing to the need for a sustainable technological solution to overcome this crisis. This review, therefore, focuses on nanotechnology and the development of antiviral nanomaterials with physical antagonistic features of viral replication checkpoints as such a solution. Our detailed discussion of SARS-CoV-2 replication and pathogenesis highlights four distinct checkpoints, the S protein (ACE2 receptor coupling), the RBD motif (ACE2 receptor coupling), ACE2 coupling, and the S protein cleavage site, as targets for the development of nano-enabled solutions that, for example, prevent viral attachment and fusion with the host cell by either blocking viral RBD/spike proteins or cellular ACE2 receptors. As proof of this concept, we highlight applications of several nanomaterials, such as metal and metal oxide nanoparticles, carbon-based nanoparticles, carbon nanotubes, fullerene, carbon dots, quantum dots, polymeric nanoparticles, lipid-based, polymer-based, lipid-polymer hybrid-based, surface-modified nanoparticles that have already been employed to control viral infections. These nanoparticles were developed to inhibit receptor-mediated host-virus attachments and cell fusion, the uncoating of the virus, viral gene expression, protein synthesis, the assembly of progeny viral particles, and the release of the virion. Moreover, nanomaterials have been used as antiviral drug carriers and vaccines, and nano-enabled sensors have already been shown to enable fast, sensitive, and label-free real-time diagnosis of viral infections. Nano-biosensors could, therefore, also be useful in the remote testing and tracking of patients, while nanocarriers probed with target tissue could facilitate the targeted delivery of antiviral drugs to infected cells, tissues, organs, or systems while avoiding unwanted exposure of non-target tissues. Antiviral nanoparticles can also be applied to sanitizers, clothing, facemasks, and other personal protective equipment to minimize horizontal spread. We believe that the nanotechnology-enabled solutions described in this review will enable us to control repeated SAR-CoV-2 waves caused by antibody escape mutations.

Surface Functionalised Parenteral Nanoemulsions for Active and Homotypic Targeting to Melanoma

Despite recent progressions in cancer genomic and immunotherapies, advanced melanoma still represents a life threat, pushing to optimise new targeted nanotechnology approaches for specific drug delivery to the tumour. To this aim, owing to their biocompatibility and favourable technological features, injectable lipid nanoemulsions were functionalised with proteins owing to two alternative approaches: transferrin was chemically grafted for active targeting, while cancer cell membrane fragments wrapping was used for homotypic targeting. In both cases, protein functionalisation was successfully achieved. Targeting efficiency was preliminarily evaluated using flow cytometry internalisation studies in two-dimensional cellular models, after fluorescence labelling of formulations with 6-coumarin. The uptake of cell-membrane-fragment-wrapped nanoemulsions was higher compared to uncoated nanoemulsions. Instead, the effect of transferrin grafting was less evident in serum-enriched medium, since such ligand probably undergoes competition with the endogenous protein. Moreover, a more pronounced internalisation was achieved when a pegylated heterodimer was employed for conjugation (p < 0.05).

Let’s Go 3D! New Generation of Models for Evaluating Drug Response and Resistance in Prostate Cancer

Prostate cancer (PC) is the third most frequently diagnosed cancer worldwide and the second most frequent in men. Several risk factors can contribute to the development of PC, and those include age, family history, and specific genetic mutations. So far, drug testing in PC, as well as in cancer research in general, has been performed on 2D cell cultures. This is mainly because of the vast benefits these models provide, including simplicity and cost effectiveness. However, it is now known that these models are exposed to much higher stiffness; lose physiological extracellular matrix on artificial plastic surfaces; and show changes in differentiation, polarization, and cell–cell communication. This leads to the loss of crucial cellular signaling pathways and changes in cell responses to stimuli when compared to in vivo conditions. Here, we emphasize the importance of a diverse collection of 3D PC models and their benefits over 2D models in drug discovery and screening from the studies done so far, outlining their benefits and limitations. We highlight the differences between the diverse types of 3D models, with the focus on tumor–stroma interactions, cell populations, and extracellular matrix composition, and we summarize various standard and novel therapies tested on 3D models of PC for the purpose of raising awareness of the possibilities for a personalized approach in PC therapy.

β-Cyclodextrin-Based Nanosponges Inclusion Compounds Associated with Gold Nanorods for Potential NIR-II Drug Delivery

This article describes the synthesis and characterization of two nanocarriers consisting of β-cyclodextrin-based nanosponges (NSs) inclusion compounds (ICs) and gold nanorods (AuNRs) for potential near-infrared II (NIR-II) drug-delivery systems. These nanosystems sought to improve the stability of two drugs, namely melphalan (MPH) and curcumin (CUR), and to trigger their photothermal release after a laser irradiation stimulus (1064 nm). The inclusion of MPH and CUR inside each NS was confirmed by field emission scanning electron microscopy (FE-SEM), Raman spectroscopy, Fourier transform infrared spectroscopy, (FT-IR) differential scanning calorimetry (DSC), transmission electron microscopy (TEM), and proton nuclear magnetic resonance (1H-NMR). Furthermore, the association of AuNRs with both ICs was confirmed by FE-SEM, energy-dispersive spectroscopy (EDS), TEM, dynamic light scattering (DLS), ζ-potential, and UV–Vis. Moreover, the irradiation assays demonstrated the feasibility of the controlled-photothermal drug release of both MPH and CUR in the second biological window (1000–1300 nm). Finally, MTS assays depicted that the inclusion of MPH and CUR inside the cavities of NSs reduces the effects on mitochondrial activity, as compared to that observed in the free drugs. Overall, these results suggest the use of NSs associated with AuNRs as a potential technology of controlled drug delivery in tumor therapy, since they are efficient and non-toxic materials.

Cyclodextrin-Based Nanosponges: Overview and Opportunities

Nanosponges are solid cross-linked polymeric nano-sized porous structures. This broad concept involves, among others, metal organic frameworks and hydrogels. The focus of this manuscript is on cyclodextrin-based nanosponges. Cyclodextrins are cyclic oligomers of glucose derived from starch. The combined external hydrophilicity with the internal hydrophobic surface constitute a unique “microenvironment”, that confers cyclodextrins the peculiar ability to form inclusion host‒guest complexes with many hydrophobic substances. These complexes may impart beneficial modifications of the properties of guest molecules such as solubility enhancement and stabilization of labile guests. These properties complemented with the possibility of using different crosslinkers and high polymeric surface, make these sponges highly suitable for a large range of applications. Despite that, in the last 2 decades, cyclodextrin-based nanosponges have been developed for pharmaceutical and biomedical applications, taking advantage of the nontoxicity of cyclodextrins towards humans. This paper provides a critical and timely compilation of the contributions involving cyclodextrins nanosponges for those areas, but also paves the way for other important applications, including water and soil remediation and catalysis.

The Effective Combination between 3D Cancer Models and Stimuli-Responsive Nanoscale Drug Delivery Systems

Stimuli-responsive drug-delivery systems (DDSs) have emerged as a potential tool for applications in healthcare, mainly in the treatment of cancer where versatile nanocarriers are co-triggered by endogenous and exogenous stimuli. Two-dimensional (2D) cell cultures are the most important in vitro model used to evaluate the anticancer activity of these stimuli-responsive DDSs due to their easy manipulation and versatility. However, some limitations suggest that these in vitro models poorly predict the outcome of in vivo studies. One of the main drawbacks of 2D cell cultures is their inadequate representation of the 3D environment’s physiological complexity, which sees cells interact with each other and the extracellular matrix (ECM) according to their specific cellular organization. In this regard, 3D cancer models are a promising approach that can overcome the main shortcomings of 2D cancer cell cultures, as these in vitro models possess many peculiarities by which they mimic in vivo tumors, including physiologically relevant cell–cell and cell–ECM interactions. This is, in our opinion, even more relevant when a stimuli-responsive DDS is being investigated. In this review, we therefore report and discuss endogenous and exogenous stimuli-responsive DDSs whose effectiveness has been tested using 3D cancer cell cultures.

Resveratrol and cyclodextrins, an easy alliance: Applications in nanomedicine, green chemistry and biotechnology

Most drugs or the natural substances reputed to display some biological activity are hydrophobic molecules that demonstrate low bioavailability regardless of their mode of absorption. Resveratrol and its derivatives belong to the chemical group of stilbenes; while stilbenes are known to possess very interesting properties, these are limited by their poor aqueous solubility as well as low bioavailability in animals and humans. Among the substances capable of forming nanomolecular inclusion complexes which can be used for drug delivery, cyclodextrins show spectacular physicochemical and biomedical implications in stilbene chemistry for their possible application in nanomedicine. By virtue of their properties, cyclodextrins have also demonstrated their possible use in green chemistry for the synthesis of stilbene glucosylated derivatives with potential applications in dermatology and cosmetics. Compared to chemical synthesis and genetically modified microorganisms, plant cell or tissue systems provide excellent models for obtaining stilbenes in few g/L quantities, making feasible the production of these compounds at a large scale. However, the biosynthesis of stilbenes is only possible in the presence of the so-called elicitor compounds, the most commonly used of which are cyclodextrins. We also report here on the induction of resveratrol production by cyclodextrins or combinatory elicitation with methyljasmonate in plant cell systems as well as the mechanisms by which they are able to trigger a stilbene response. The present article therefore discusses the role of cyclodextrins in stilbene chemistry both at the physico-chemical level as well as the biomedical and biotechnological levels, emphasizing the notion of "easy alliance" between these compounds and stilbenes.

Cyclodextrin Nanosponges Inclusion Compounds Associated with Gold Nanoparticles for Potential Application in the Photothermal Release of Melphalan and Cytoxan

This article describes the synthesis and characterization of β-cyclodextrin-based nano-sponges (NS) inclusion compounds (IC) with the anti-tumor drugs melphalan (MPH) and cytoxan (CYT), and the addition of gold nanoparticles (AuNPs) onto both systems, for the potential release of the drugs by means of laser irradiation. The NS-MPH and NS-CYT inclusion compounds were characterized using scanning electron microscopy (SEM), X-ray powder diffraction (XRPD), energy dispersive spectroscopy (EDS), thermogravimetric analysis (TGA), UV-Vis, and proton nuclear magnetic resonance (1H-NMR). Thus, the inclusion of MPH and CYT inside the cavities of NSs was confirmed. The association of AuNPs with the ICs was confirmed by SEM, EDS, TEM, and UV-Vis. Drug release studies using NSs synthesized with different molar ratios of β-cyclodextrin and diphenylcarbonate (1:4 and 1:8) demonstrated that the ability of NSs to entrap and release the drug molecules depends on the crosslinking between the cyclodextrin monomers. Finally, irradiation assays using a continuous laser of 532 nm showed that photothermal drug release of both MPH and CYT from the cavities of NSs via plasmonic heating of AuNPs is possible.