Recent advances in cyclodextrin delivery techniques

Advancements in application of chitosan and cyclodextrins in biomedicine and pharmaceutics: recent progress and future trends

The global community is faced with numerous health concerns such as cancer, cardiovascular and neurological diseases, diabetes, joint pain, osteoporosis, among others. With the advancement of research in the fields of materials chemistry and medicine, pharmaceutical technology and biomedical analysis have entered a new stage of development. The utilization of natural oligosaccharides and polysaccharides in pharmaceutical/biomedical studies has gained significant attention. Over the past decade, several studies have shown that chitosan and cyclodextrin have promising biomedical implications in background analysis, ongoing development, and critical applications in biomedical and pharmaceutical research fields. This review introduces different types of saccharides/natural biopolymers such as chitosan and cyclodextrin and discusses their wide-ranging applications in the biomedical/pharmaceutical research area. Recent research advances in pharmaceutics and drug delivery based on cyclodextrin, and their response to smart stimuli, as well as the biological functions of cyclodextrin and chitosan, such as the immunomodulatory effects, antioxidant, and antibacterial properties, have also been discussed, along with their applications in tissue engineering, wound dressing, and drug delivery systems. Finally, the innovative applications of chitosan and cyclodextrin in the pharmaceutical/biomedicine were reviewed, and current challenges, research/technological gaps, and future development opportunities were surveyed.

Multifunctionality of cyclodextrin-based polymeric nanoparticulate delivery systems for chemotherapeutics, combination therapy, and theranostics

As cancer being the most difficult disease to treat, different kinds of medications and therapeutic approaches have been prominently developed by scientists. For certain families of drugs, such as immuno-therapeutics or antibody-drug conjugates, efficient delivery systems are required during administration to protect the drugs from chemical degradation or biological inactivation. Delivery systems with the ability to carry different therapeutics or diagnostic agents or both, hold promising potential to tackle the abnormalities behind cancer. In this context, this review provides updated insights on how cyclodextrin-based polymeric nanosystems have become an effective treatment approach against cancer. Cyclodextrins (CDs) are natural oligosaccharides that are famously exploited in pharmaceutical research due to their exceptional quality of entrapping water-insoluble molecules inside their hydrophobic core and providing enhanced solubility with the help of their hydrophilic exterior. Combining the properties of CDs with polymeric nanoparticles (PNPs) brings out excellent versatile and tunable profiles, thanks to the submicron-sized PNPs. By introducing the significance of CD as a delivery system, a collective discussion on different binding approaches and release mechanisms of CD-drug complexation, followed by their characterization studies has been done in this review. Further, in light of recent studies, the article majorly focuses on conveying how promoting CD to a polymeric and nanoscale elevates the multifunctional advantages against cancer that can be successfully applied in combination therapy and theranostics. Moreover, CD-based delivery systems including CALAA-01, CRLX101, and CRLX301, have demonstrated improved tumor targeting, reduced side effects, and prolonged drug release in preclinical studies and clinical trials.

A Comprehensive Review on the Benefits and Problems of Curcumin with Respect to Human Health

Curcumin is the most important active component in turmeric extracts. Curcumin, a natural monomer from plants has received a considerable attention as a dietary supplement, exhibiting evident activity in a wide range of human pathological conditions. In general, curcumin is beneficial to human health, demonstrating pharmacological activities of anti-inflammation and antioxidation, as well as antitumor and immune regulation activities. Curcumin also presents therapeutic potential in neurodegenerative, cardiovascular and cerebrovascular diseases. In this review article, we summarize the advancements made in recent years with respect to curcumin as a biologically active agent in malignant tumors, Alzheimer’s disease (AD), hematological diseases and viral infectious diseases. We also focus on problems associated with curcumin from basic research to clinical translation, such as its low solubility, leading to poor bioavailability, as well as the controversy surrounding the association between curcumin purity and effect. Through a review and summary of the clinical research on curcumin and case reports of adverse effects, we found that the clinical transformation of curcumin is not successful, and excessive intake of curcumin may have adverse effects on the kidneys, heart, liver, blood and immune system, which leads us to warn that curcumin has a long way to go from basic research to application transformation.

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.

Exploration on the drug solubility enhancement in aqueous medium with the help of endo-functionalized molecular tubes: a computational approach

One major problem in the pharmaceutical industry is the aqueous solubility of newly developed orally administered drug candidates. More than 50% of newly developed drug molecules suffer from low aqueous solubility. The therapeutic effects of drug molecules are majorly dependent on the bioavailability and, in essence, on the solubility of the used drug molecules. Thus, enhancement of drug solubility of sparingly soluble drug molecules is a need of modern times. Considering the high importance of drug solubility, we have computationally shown the enhancement of drug solubility for seven class II (poorly water-soluble) drug molecules in a water medium. The uses of supramolecular macrocycles have immense importance in the same field. Thus, we have used two synthetic supramolecular receptors named host-1a and host-1b to enhance the water solubility of fluorouracil, albendazole, camptothecin, clopidogrel, indomethacin, melphalan, and tolfenamic acid drug molecules. Biomedical engagements of a supramolecular receptor commence with the formation of stable host-drug complexes. These complexations enhance the water solubility of drug molecules and sustain the release rate and bioavailability of drug molecules. Thus, in this work, we focus on the formation of stable host-drug complexes in water medium. Molecular dynamics simulation is applied to analyze the structural features and the energetics involved in the host-drug complexation process. The information obtained at the atomistic level helps us gain better insights into the key interactions that operate to produce such highly stable complexes. Thus, we can propose that these two supramolecular receptors may be used as drug solubilizing agents, and patients will benefit from this theragnostic application shortly.

Hydrogels: soft matters in photomedicine

Photodynamic therapy (PDT), a shining beacon in the realm of photomedicine, is a non-invasive technique that utilizes dye-based photosensitizers (PSs) in conjunction with light and oxygen to produce reactive oxygen species to combat malignant tissues and infectious microorganisms. Yet, for PDT to become a common, routine therapy, it is still necessary to overcome limitations such as photosensitizer solubility, long-term side effects (e.g., photosensitivity) and to develop safe, biocompatible and target-specific formulations. Polymer based drug delivery platforms are an effective strategy for the delivery of PSs for PDT applications. Among them, hydrogels and 3D polymer scaffolds with the ability to swell in aqueous media have been deeply investigated. Particularly, hydrogel-based formulations present real potential to fulfill all requirements of an ideal PDT platform by overcoming the solubility issues, while improving the selectivity and targeting drawbacks of the PSs alone. In this perspective, we summarize the use of hydrogels as carrier systems of PSs to enhance the effectiveness of PDT against infections and cancer. Their potential in environmental and biomedical applications, such as tissue engineering photoremediation and photochemistry, is also discussed.

CDI cross-linked β-cyclodextrin nanosponges of paliperidone: synthesis and physicochemical characterization

Paliperidone (PLP) is an antipsychotic drug indicated for treatment and management of schizophrenia. The current study demonstrates potential of PLP-loaded β-cyclodextrin-based nanosponges (CDNS) for solubility enhancement and prolonged release of PLP. The inclusion complexes of PLP with carbonyldiimidazole (CDI) cross-linked nanosponges were synthesized. The drug-loaded CDNS were characterized for particle size, zeta potential, encapsulation efficiency, stability study, in vitro drug release studies. The interaction of PLP with CDNS was ascertained by FTIR, DSC and PXRD studies. The particle size and zeta potential values were sufficient to obtain stable formulations. Solubility was significantly increased and in vitro drug release studies revealed prolonged release of PLP from the CDNS for 6 h. PXRD study revealed that the crystallinity of PLP was decreased due to complexation with the CDNS. Thus, cyclodextrin-based nanosponges represent a novel approach for solubility enhancement and improved dissolution of selected model drug PLP.

Gene delivery based on macrocyclic amphiphiles

Gene therapy, with an important role in biomedicine, often requires vectors for gene condensation in order to avoid degradation, improve membrane permeation, and achieve targeted delivery. Macrocyclic molecules are a family of artificial receptors that can selectively bind a variety of guest species. Amphiphilic macrocycles, particularly those bearing cationic charges and their various assemblies represent a new class of promising non-viral vectors with intrinsic advantages in gene condensation and delivery. The most prominent examples include amphiphilic cyclodextrins, calixarenes and pillararenes. Herein, we systemically reviewed reported assemblies of amphiphilic macrocycles for gene delivery and therapy. The advantages and disadvantages of each type of macrocyclic amphiphiles for gene delivery, as well as the perspectives on the future development of this area are discussed.

Cyclodextrin-Based Metal-Organic Frameworks (CD-MOFs) in Pharmaceutics and Biomedicine

Metal-organic frameworks (MOFs) show promising application in biomedicine and pharmaceutics owing to their extraordinarily high surface area, tunable pore size, and adjustable internal surface properties. However, MOFs are prepared from non-renewable or toxic materials, which limit their real-world applications. Cyclodextrins (CDs) are a typical natural and biodegradable cyclic oligosaccharide and are primarily used to enhance the aqueous solubility, safety, and bioavailability of drugs by virtue of its low toxicity and highly flexible structure, offering a peculiar ability to form CD/drug inclusions. A sophisticated strategy where CD is deployed as a ligand to form an assembly of cyclodextrin-based MOFs (CD-MOFs) may overcome real-world application drawbacks of MOFs. CD-MOFs incorporate the porous features of MOFs and the encapsulation capability of CD for drug molecules, leading to outstanding properties when compared with traditional hybrid materials. This review focuses on the inclusion technology and drug delivery properties associated with CD-MOFs. In addition, synthetic strategies and currently developed uses of CD-MOFs are highlighted as well. Also, perspectives and future challenges in this rapidly developing research area are discussed.

Polymeric Nanocarriers for the Delivery of Antimalarials

Malaria is an infectious disease caused by a protozoan parasite which is transmitted by female Anopheles mosquitoes around tropical and sub-tropical regions. Half of the world's population is at risk of being infected by malaria. This mainly includes children, pregnant women and people living with chronic diseases. The main factor that has contributed to the spread of this disease is the increase in the number of drug-resistant parasites. To overcome drug resistance, researchers have developed drug delivery systems from biodegradable polymers for the loading of antimalarials. The drug delivery systems were characterized by distinct features such as good biocompatibility, high percentage drug encapsulation, reduced drug toxicity and targeted drug delivery. In this review article, we highlight the various types of drug delivery systems developed from polymeric nanocarriers used for the delivery of antimalarials.

Supramolecular Complex of Ibuprofen with Larch Polysaccharide Arabinogalactan: Studies on Bioavailability and Pharmacokinetics

BACKGROUND AND OBJECTIVES

In the present work, pharmacological and pharmacokinetic properties of the supramolecular complex of non-steroid anti-inflammatory drug ibuprofen (IBU) with natural polysaccharide arabinogalactan (AG) were studied. The main goals of such complexation were the increase of ibuprofen's bioavailability and decrease its effective dose after oral administration.

METHODS

The complex with mass ratio as IBU:AG 1:10 was obtained by mechanochemical synthesis and characterized by water solubility, electron microscopy, differential scanning calorimetry, X-ray powder diffraction analysis and ¹H-nuclear magnetic resonance spectroscopy. Different animal models of pain and inflammation was used to investigate IBU:AG biological effects. Plasma concentration of IBU and its pharmacokinetic parameters were evaluated after oral introduction.

RESULTS

It was found that ibuprofen's effective analgesic and anti-inflammatory dose decreased twofold after its introduction as a complex with AG. The reason of this difference is due to the increase of ibuprofen concentration in rats' plasma: C _max of IBU at doses of 20 and 40 mg/kg was found as 0.088 and 0.132 μg/ml, whereas C _max of IBU in the complex form was 0.103 and 0.160 μg/ml, respectively.

CONCLUSIONS

Thus, we have shown that complexation of the IBU with AG results in its bioavailability increase, reduction of the effective dose and should decrease toxic side effects.

Potential therapeutic application of dendrimer/cyclodextrin conjugates with targeting ligands as advanced carriers for gene and oligonucleotide drugs

Despite the recent approval of some gene medicines and nucleic acid drugs, further improvement of delivery techniques for these drugs is strongly required. Several delivery technologies for these drugs have been developed, in other words, viral and two types of nonviral (lipofection and polyfection) vectors. Among the polyfection system, the potential use of various cyclodextrin (CyD) derivatives and CyD-appended polymers as carriers for gene and nucleic acid drugs has been demonstrated. The polyamidoamine dendrimer (G3) conjugates with α-CyD (α-CDE (G3)) have been reported to possess noteworthy properties as DNA and nucleic acid drugs carriers. This review will focus on the attempts to develop such cell-specific drug carriers by preparing polyethylene glycol, galactose, lactose, mannose, fucose and folic acid-appended α-CDEs as tissue and cell-selective carriers of gene and nucleic acid drugs.

Cyclodextrin polymers as nanocarriers for sorafenib

Polymeric nanoparticles based on cyclodextrins are currently undergoing clinical trials as new promising nanotherapeutics. In light of this interest, we investigated cyclodextrin cross-linked polymers with different lengths as carriers for the poorly water-soluble drug sorafenib. Both polymers significantly enhanced sorafenib solubility, with shorter polymers showing the most effective solubilizing effect. Inclusion complexes between sorafenib and the investigated polymers exhibited an antiproliferative effect in tumor cells similar to that of free sorafenib. Polymer/Sorafenib complexes also showed lower in vivo tissue toxicity than with free sorafenib in all organs. Our results suggest that the inclusion of sorafenib in polymers represents a successful strategy for a new formulation of this drug.

Cyclodextrins improving the physicochemical and pharmacological properties of antidepressant drugs: a patent review

INTRODUCTION

Depression is a serious mood disorder and is one of the most common mental illnesses. Despite the availability of several classes of antidepressants, a substantial percentage of patients are unresponsive to these drugs, which have a slow onset of action in addition to producing undesirable side effects. Some scientific evidence suggests that cyclodextrins (CDs) can improve the physicochemical and pharmacological profile of antidepressant drugs (ADDs). The purpose of this paper is to disclose current data technology prospects involving antidepressant drugs and cyclodextrins.

AREAS COVERED

We conducted a patent review to evaluate the antidepressive activity of the compounds complexed in CDs, and we analyzed whether these complexes improved their physicochemical properties and pharmacological action. The present review used 8 specialized patent databases for patent research, using the term 'cyclodextrin' combined with 'antidepressive agents' and its related terms. We found 608 patents. In the end, considering the inclusion criteria, 27 patents reporting the benefits of complexation of ADDs with CDs were included.

EXPERT OPINION

The use of CDs can be considered an important tool for the optimization of physicochemical and pharmacological properties of ADDs, such as stability, solubility and bioavailability.

Viscosity reduction of isotonic solutions of the photosensitizer TPCS2a by cyclodextrin complexation

Meso-tetraphenyl chlorin disulphonate (TPCS_2a) is a photosensitizer (PS) particularly developed and patented for use in the technology of photochemical internalization (PCI) against cancer. TPCS_2a is known to aggregate in aqueous media even at low concentrations (≥0.1 µM) and to form a high-viscosity network at clinically relevant concentrations (mM). The aim of this work was to evaluate the effect of two hydroxypropylated cyclodextrin derivatives of beta and gamma type, respectively i.e. HPβCD and HPγCD, on the aggregation and solubilization of TPCS_2a in isotonic solutions. Samples containing micromolar concentrations of TPCS_2a were studied spectrophotometrically, while samples containing a clinical relevant concentration (10 mM = 9 mg/ml) of TPCS_2a were evaluated by dynamic viscosity measurements. HPβCD was determined to be a more suitable solubilizer of TPCS_2a than HPγCD in aqueous media both in the absence and presence of salt. The complexation stoichiometry between TPCS_2a/HPβCD at micromolar to millimolar concentrations of TPCS_2a was determined to be 1:3 and 1:2 in the absence and presence of isotonic NaCl, respectively. The network of TPCS_2a (10 mM) was broken down in the presence of 3% w/v (= 20 mM) HPβCD, i.e. a 1:2 molar ratio between TPCS_2a and the cyclodextrin. Formation of the inclusion complex resulted in low viscosity samples both in water and in the presence of isotonic NaCl or phosphate buffered saline (PBS) at 25 °C and 37 °C.

A clue to unprecedented strategy to HIV eradication: "Lock-in and apoptosis"

Despite the development of antiretroviral therapy against HIV, eradication of the virus from the body, as a means to a cure, remains in progress. A “kick and kill” strategy proposes “kick” of the latent HIV to an active HIV to eventually be “killed”. Latency-reverting agents that can perform the “kick” function are under development and have shown promise. Management of the infected cells not to produce virions after the “kick” step is important to this strategy. Here we show that a newly synthesized compound, L-HIPPO, captures the HIV-1 protein Pr55^Gag and intercepts its function to translocate the virus from the cytoplasm to the plasma membrane leading to virion budding. The infecting virus thus “locked-in” subsequently induces apoptosis of the host cells. This “lock-in and apoptosis” approach performed by our novel compound in HIV-infected cells provides a means to bridge the gap between the “kick” and “kill” steps of this eradication strategy. By building upon previous progress in latency reverting agents, our compound appears to provide a promising step toward the goal of HIV eradication from the body.

Potential Use of Cyclodextrins as Drug Carriers and Active Pharmaceutical Ingredients

Cyclodextrins (CyDs) are extensively used in various fields, and especially have been widely utilized as pharmaceutical excipients and drug carriers in the pharmaceutical field. Owing to the multi-functional and biocompatible characteristics, CyDs can improve the undesirable properties of drug molecules. This review outlines the current application of CyDs in pharmaceutical formulations, focusing on their use as CyD-based drug carriers for several kinds of drugs. Additionally, CyDs have great potential as active pharmaceutical ingredients against various diseases with few side effects.

Inclusion Complexation of Etodolac with Hydroxypropyl-beta-cyclodextrin and Auxiliary Agents: Formulation Characterization and Molecular Modeling Studies

The present investigation was aimed to prepare inclusion complexes of a therapeutically important nonsteroidal anti-inflammatory drug, etodolac (ETD) with hydroxypropyl-beta-cyclodextrin (HP-β-CD) and to study the effect of l-arginine (l-Arg) as an auxiliary agent on the complexation efficiency of HP-β-CD to improve aqueous solubility and the dissolution property of ETD. The binary and ternary complexes were prepared by physical mixing, coevaporation, and spray drying methods. The complexes were characterized using differential scanning colorimetry (DSC), Fourier transform-infrared spectroscopy (FT-IR), and powder X-ray diffraction (PXRD) studies. The mechanism of inclusion interaction of guest and host was established through ¹H NMR, molecular docking, and molecular dynamics studies. On the basis of preliminary screening studies, l-Arg was found to be the most efficient auxiliary agent for the present research problem. The change in crystallinity of ETD was evident from DSC and PXRD studies which indicated the formation of new solid forms. A remarkable increase in apparent stability constant (K_c) and complexation efficiency (CE) of HP-β-CD was observed in the presence of l-Arg in ternary complexes with improvement in solubility and dissolution of ETD than binary complexes. However, inclusion complexes of ETD obtained by computational studies is in good correlation with the results obtained through experimental methods. More stable complex formation with l-Arg was confirmed by molecular simulation studies too. Thus, the present study led to the conclusion that the ternary complex of ETD-HP-β-CD-l-Arg could be an innovative approach to augment the solubility and dissolution behavior of ETD.

Self-Assembly PEGylation Retaining Activity (SPRA) Technology via a Host-Guest Interaction Surpassing Conventional PEGylation Methods of Proteins

Polyethylene glycol (PEG) modification (PEGylation) is one of the best approaches to improve the stabilities and blood half-lives of protein drugs; however, PEGylation dramatically reduces the bioactivities of protein drugs. Here, we present "self-assembly PEGylation retaining activity" (SPRA) technology via a host-guest interaction between PEGylated β-cyclodextrin (PEG-β-CyD) and adamantane-appended (Ad) proteins. PEG-β-CyD formed stable complexes with Ad-insulin and Ad-lysozyme to yield SPRA-insulin and SPRA-lysozyme, respectively. Both SPRA-proteins showed high stability against heat and trypsin digest, comparable with that of covalently PEGylated protein equivalents. Importantly, the SPRA-lysozyme possessed ca. 100% lytic activity, whereas the activity of the covalently PEGylated lysozyme was ca. 23%. Additionally, SPRA-insulin provided a prolonged and peakless blood glucose profile when compared with insulin glargine. It also showed no loss of activity. In contrast, the covalently PEGylated insulin showed a negligible hypoglycemic effect. These findings indicate that SPRA technology has potential as a generic method, surpassing conventional PEGylation methods for proteins.

Thermoresponsive supramolecular micellar drug delivery system based on star-linear pseudo-block polymer consisting of β-cyclodextrin-poly(N-isopropylacrylamide) and adamantyl-poly(ethylene glycol)

Chemotherapy is facing several limitations such as low water solubility of anticancer drugs and multidrug resistance (MDR) in cancer cells. To overcome these limitations, a thermoresponsive micellar drug delivery system formed by a non-covalently connected supramolecular block polymer was developed. The system is based on the host-guest interaction between a well-defined β-cyclodextrin (β-CD) based poly(N-isopropylacrylamide) star host polymer and an adamantyl-containing poly(ethylene glycol) (Ad-PEG) guest polymer. The structures of the host and guest polymers were characterized by ¹H and ¹³C NMR, GPC and FTIR. Subsequently, they formed a pseudo-block copolymer via inclusion complexation between β-CD core and adamantyl-moiety, which was confirmed by 2D NMR. The thermoresponsive micellization of the copolymer was investigated by UV-vis spectroscopy, DLS and TEM. At 37°C, the copolymer at a concentration of 0.2mg/mL in PBS formed micelles with a hydrodynamic diameter of ca. 282nm. The anticancer drug, doxorubicin (DOX), was successfully loaded into the core of the micelles with a loading level of 6% and loading efficiency of 17%. The blank polymer micelles showed good biocompatibility in cell cytotoxicity studies. Moreover, the DOX-loaded micelles demonstrated superior therapeutic effects in AT3B-1-N (MDR-) and AT3B-1 (MDR+) cell lines as compared to free DOX control, overcoming MDR in cancer cells.

Inclusion of terpenes in cyclodextrins: Preparation, characterization and pharmacological approaches

Terpenes constitute the largest class of natural products and are important resources for the pharmaceutical, food and cosmetics industries. However, due to their low water solubility and poor bioavailability there has been a search for compounds that could improve their physicochemical properties. Cyclodextrins (natural and derived) have been proposed for this role and have been complexed with different types of terpenes. This complexation has been demonstrated by using analytical techniques for characterizing complexes such as DSC, NMR, XRD, FTIR, and TGA. The formation of inclusion complexes has been able to improve drug characteristics such as bioavailability, solubility and stability; and to enhance biological activity and efficacy. This review shows strong experimental evidence that cyclodextrins improve the pharmacological properties of terpenes, and therefore need to be recognized as being possible targets for clinical use.

Aminocyclodextrin Oligomers as Protective Agents of Protein Aggregation

Over 30 different amyloid proteins and a number of corresponding protein-misfolding diseases have been identified. Among these is Alzheimer's disease, the most common neurodegenerative disorder. The treatment of these diseases is still a goal to reach and many molecules have been studied in this context. Among these, the cyclodextrins have shown interesting potential as agents against protein aggregation (antiaggregants). On the basis of this interest, we investigated the effect on protein aggregation of some oligomers of β-cyclodextrins. In particular, it was found that amino oligomers show good inhibition of β-amyloid aggregation in the micromolar concentration range. The presence of both a multicavity system and amino groups seems to be essential for preventing protein aggregation.

Cyclodextrins as Protective Agents of Protein Aggregation: An Overview

Cyclodextrins are extensively used in different fields (e.g., catalysis, chromatography, pharma, supramolecular chemistry, bioorganic chemistry, and bioinorganic chemistry), and their applications have been widely reviewed. Their main application in the field of pharmaceutical is as a drug carrier. This review overviews, for the first time, the use of cyclodextrins and their derivatives as antiaggregant agents in a number of proteins (e.g., amyloid-β, insulin, recombinant human growth hormone, prion protein, transthyretin, and α-synuclein) and some multimeric enzymes. There are many diseases that are correlated to protein misfolding and amyloid formation processes affecting numerous organs and tissues. There are over 30 different amyloid proteins and a number of corresponding diseases. Alzheimer's disease is the most common neurodegenerative disease. Treatment of these diseases is still a goal to reach, and many molecules are studied in this perspective. Cyclodextrins have also been studied, and they show great potential; as such, further studies could be very promising. This review aims to be a stimulus for the design of new cyclodextrin derivatives to obtain multifunctional systems with antiaggregant activity.

Cyclodextrin polymers as carriers for the platinum-based anticancer agent LA-12

Cyclodextrin-based drug nanocarriers look very promising for improving the cytotoxicity of LA-12.

Powering up the molecular therapy of RNA interference by novel nanoparticles

With more suitable for disease treatment due to reduced cellular toxicity, higher loading capacity, and better biocompatibility, nanoparticle-based siRNA delivery systems have proved to be more potent, higher specific and less toxic than the traditional drug therapy.

Cyclodextrins in pharmaceutical formulations II: solubilization, binding constant, and complexation efficiency

Cyclodextrins are cyclic oligosaccharides that have been recognized as pharmaceutical adjuvants for the past 20 years. The molecular structure of these glucose derivatives, which approximates a truncated cone, bucket, or torus, generates a hydrophilic exterior surface and a nonpolar interior cavity. Cyclodextrins can interact with appropriately sized drug molecules to yield an inclusion complex. These noncovalent inclusion complexes offer a variety of advantages over noncomplexed forms of a drug. Cyclodextrins are carbohydrates that are primarily used to enhance the aqueous solubility, physical chemical stability, and bioavailability of drugs. Their other applications include preventing drug-drug interactions, converting liquid drugs into microcrystalline powders, minimizing gastrointestinal and ocular irritation, and reducing or eliminating unpleasant taste and smell. Here, we focus on the solubilization of drugs by complexation, and discuss the determination and significance of binding constants for cyclodextrin complexes, and the determination of complexation efficiency and factors that influence it. We also make some general observations on cyclodextrin complexation and the use of cyclodextrins in solid, as well as parenteral, dosage forms.