Vesicular gold assemblies based on host-guest inclusion and its controllable release of doxorubicin

Directional Self-Assembly of Nanoparticles Coated with Thermoresponsive Block Copolymers and Charged Small Molecules

Herein, we report the directional stimuli-responsive self-assembly of gold nanoparticles (AuNPs) coated with a thermoresponsive block copolymer (BCP), poly(ethylene glycol)-b-poly(N-isopropylacrylamide) (PEG-b-PNIPAM) and charged small molecules. AuNPs modified with PEG-b-PNIPAM possessing a AuNP/PNIPAM/PEG core/active/shell structure undergo temperature-induced self-assembly into one-dimensional (1D) or two-dimensional (2D) structures in salt solutions, with the morphology varying with the ionic strength of the medium. Salt-free self-assembly is also realized by modulating the surface charge by the codeposition of positively charged small molecules; 1D or 2D assemblies are formed depending on the ratio between the small molecule and PEG-b-PNIPAM, consistent with the trend observed with the bulk salt concentration. A series of charge-controlled self-assembly at various conditions revealed that the temperature-induced BCP-mediated self-assembly reported here provides an effective means for on-demand directional self-assembly of nanoparticles (NPs) with controlled morphology, interparticle distance, and optical properties, and the fixation of high-temperature structures.

Cyclodextrin-Based Arsenal for Anti-Cancer Treatments

Anti-cancer drugs are mostly limited in their use due to poor physicochemical and biopharmaceutical properties. Their lower solubility is the most common hurdle limiting their use upto their potential. In the recent years, the cyclodextrin (CD) complexation have emerged as existing approach to overcome the problem of poor solubility. CD-based nano-technological approaches are safe, stable and showed well in vivo tolerance and greater payload for encapsulation of hydrophobic drugs for the targeted delivery. They are generally chosen due to their ability to get self-assembled to form liposomes, nanoparticles, micelles and nano-sponges etc. This review paper describes a birds-eye view of the various CD-based nano-technological approaches applied for the delivery of anti-cancer moieties to the desired target such as CD based liposomes, niosomes, niosoponges, micelles, nanoparticles, monoclonal antibody, magnetic nanoparticles, small interfering RNA, nanorods, miscellaneous formulation of anti-cancer drugs containing CD. Moreover, the author also summarizes the various shortcomings of such a system and their way ahead.

Cyclodextrins-modified metallic nanoparticles for effective cancer therapy

Cancer, a disease of unknown origin is the second most common reason of death worldwide after heart attacks and therefore is a major threat to human beings. Currently, chemotherapy is the only approach for delivering anti-cancer drugs but shows severe systemic toxicities such as alopecia, loss of appetite, anemia, gastric irritation, neurotoxicity and nephrotoxicity. Additionally, chemotherapeutics fails to achieve the expected therapeutic outcome due to their limited solubility, in-vivo instability and lack of targeting efficiency. Encapsulating drugs in metallic nanoparticles like gold, silver and metal oxides (magnetic) help to overcome limitations of chemotherapy and transports anti-cancer drugs effectively at the targeted site due to the advantages such as optimal size, surface morphology, higher conductivity and in-vivo stability. Moreover, these metals can be triggered externally using NIR radiations or magnetic field thereby improving the drug release kinetics. Some frequently used chemotherapeutic agents such as doxorubicin, paclitaxel, methotrexate, etc. degrade rapidly due to their hydrophobic nature and show in-vivo instability. Cyclodextrin offers structural compatibility for encapsulating such hydrophobic drugs and improves their loading capacity, solubility and stability without showing any systemic toxicities. Therefore, researchers designed cyclodextrin-complexed metallic nanoparticles as a novel platform to overcome pitfalls of conventional chemotherapy like gastric irritation, hair loss, neurotoxicity, etc. This review article provides detail insight of metallic nanocarriers containing cyclodextrin-encapsulated anti-cancer agents for effective cancer therapy. It can be concluded that this novel approach holds a great potential for clinical application in cancer diagnosis, treatment with minimum toxicity and maximum efficacy.

Cyclodextrins and inorganic nanoparticles: Another tale of synergy

In this review, we summarize the recent research focused on the combination of inorganic nanoparticles and α-, β- and γ- cyclodextrins. Our intention is to highlight the most relevant publications on the synthesis of nanoparticle-cyclodextrin (NP-CD) nanohybrids, with CDs acting as reducing agents or through the post-synthetic modification of inorganic nanoparticles with CDs. We also discuss the new or enhanced properties that arise from the host-guest capabilities of the CDs and inorganic nanoparticles. Finally, we illustrate the potential applications of these materials in numerous research fields.

Advances of nanosystems containing cyclodextrins and their applications in pharmaceuticals

For many years, researchers have worked with supramolecular structures involving inclusion complexes with cyclodextrins. These studies have resulted in new commercially available drugs which have been of great benefit. More recently, studies using nanoparticles, including nanosystems containing cyclodextrins, have become a focus of academic research due to the versatility of the systems and their remarkable therapeutic potential. This review focuses on studies published between 2002 and 2018 involving nanosystems containing cyclodextrins. We consider the type of nanosystems, their importance in a health context, the physicochemical techniques used to show the quality of these systems and their potential for the development of novel pharmaceutical formulations. These have been developed in recent studies which have mainly been focusing on basic science with no clinical trials as yet being performed. This is important to note because it means that the studies do not include any toxicity tests. Despite this limitation, the characterization assays performed suggest that these new formulations may have therapeutic potential. However, more research is required to assess the efficacy and safety of these nanosystems.

Reactive Oxygen Species and Glutathione Dual Redox-Responsive Supramolecular Assemblies with Controllable Release Capability

A dual redox and biorelevant triggered supramolecular system is developed through noncovalent supramolecular inclusion interactions between the ferrocene (Fc) modified on camptothecin (CPT) and β-cyclodextrin (β-CD) at the end of methoxy polyethylene glycol (mPEG). With these two segments, a stable noncovalent supramolecular structure, i.e., mPEG-β-CD/Fc-CPT, can be formed, and then self-assembled into micellar structures in water. Interestingly, these supramolecular micelles showed uniform sphere structure, high and constant drug loading content, hyper-fast redox-responsive drug release, and exhibited equal cellular proliferation inhibition toward A549 cancer cells. The cytotoxicity evaluation of mPEG-β-CD also indicated good biocompatibility. In vivo results revealed the mPEG-β-CD/Fc-CPT nanoparticles had higher in vivo efficacy without side effects. It is anticipated this supramolecular complex may serve as a new kind of promising alternative for drug delivery systems.

Carbohydrate-based amphiphilic nano delivery systems for cancer therapy

Nanoparticles (NPs) are novel drug delivery systems that have been attracting more and more attention in recent years, and have been used for the treatment of cancer, infection, inflammation and other diseases. Among the numerous classes of materials employed for constructing NPs, organic polymers are outstanding due to the flexibility of design and synthesis and the ease of modification and functionalization. In particular, NP based amphiphilic polymers make a great contribution to the delivery of poorly-water soluble drugs. For example, natural, biocompatible and biodegradable products like polysaccharides are widely used as building blocks for the preparation of such drug delivery vehicles. This review will detail carbohydrate based amphiphilic polymeric systems for cancer therapy. Specifically, it focuses on the nature of the polymer employed for the preparation of targeted nanocarriers, the synthetic methods, as well as strategies for the application and evaluation of biological activity. Applications of the amphiphilic polymer systems include drug delivery, gene delivery, photosensitizer delivery, diagnostic imaging and specific ligand-assisted cellular uptake. As a result, a thorough understanding of the relationship between chemical structure and biological properties facilitate the optimal design and rational clinical application of the resulting carbohydrate based nano delivery systems for cancer therapy.

Tunable polymer brush/Au NPs hybrid plasmonic arrays based on host-guest interaction

The fabrication of versatile gold nanoparticle (Au NP) arrays with tunable optical properties by a novel host-guest interaction are presented. The gold nanoparticles were incorporated into polymer brushes by host-guest interaction between β-cyclodextrin (β-CD) ligand of gold nanoparticles and dimethylamino group of poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA). The gold nanoparticle arrays were prepared through the template of PDMAEMA brush patterns which were fabricated combining colloidal lithography and surface-initiated atom-transfer radical polymerization (SI-ATRP). The structure parameters of gold nanoparticle patterns mediated by polymer brushes such as height, diameters, periods and distances, could be easily tuned by tailoring the etching time or size of colloidal spheres in the process of colloidal lithography. The change of optical properties induced by different gold nanoparticle structures was demonstrated. The direct utilization of PDMAEMA brushes as guest avoids a series of complicated modification process and the PDMAEMA brushes can be grafted on various substrates, which broaden its applications. The prepared gold naoparticle arrays are promising in applications of nanosensors, memory storage and surface enhanced spectroscopy.

Nanoassemblies driven by cyclodextrin-based inclusion complexation

Nanoassemblies driven by cyclodextrin-based inclusion complexation as functional nanomaterials.