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We describe a mild, ecofriendly, and straightforward two-step strategy for making core-shell Au@Ag bimetallic nanoparticles (BMNPs) for antibacterial nanomedicine and SERS imaging. The synthesis exploits the unique properties of the cationic polymeric cyclodextrin (PolyCD) as both reducing and stabilizing agent to obtain, monodispersed and stable Au@Ag BMNPs. PolyCD-driven protocol includes the synthesis of PolyCD-coated Au monometallic nanoparticles (MNPs) as a seed material for the subsequent growing of a silver shell. PolyCD was produced by polymerization of the azido modified βCD monomers with epichlorohydrin and subsequent reduction of azido derivative. The amino groups, as hydrochloride salts (one for CD ring), are pivotal for the formation of BMNPs in mild conditions. Nanoantibiotics and SERS-nanoTag were prepared by complexation of Au@Ag BMNPs with Linezolid (Lz) and 4-mercaptophenyl boronic acid, respectively. Au@Ag@Lz complexes showed a good antibacterial activity against all tested microorganisms including the methicillin resistant Staphylococcus aureus (MRSA).

In the last decade, nanotechnological progress has generated new opportunities to improve the safety and efficacy of conventional anticancer therapies. Compared with other carriers, graphene nanoplatforms possess numerous tunable functionalities for the loading of multiple bioactive compounds, although their biocompatibility is still a debated concern. Recently, we have investigated the modulation of genes involved in cancer-associated canonical pathways induced by graphene engineered with cyclodextrins (GCD). Here, we investigated the GCD impact on cells safety, the HEp-2 responsiveness to Doxorubicin (DOX) and the cancer-related intracellular signalling pathways modulated by over time exposure to DOX loaded on GCD (GCD@DOX). Our studies evidenced that both DOX and GCD@DOX induced p53 and p21 signalling resulting in G0/G1 cell cycle arrest. A genotoxic behaviour of DOX was reported via detection of CDK (T14/Y15) activation and reduction of Wee-1 expression. Similarly, we found a cleavage of PARP by DOX within 72 h of exposure. Conversely, GCD@DOX induced a late cleavage of PARP, which could be indicative of less toxic effect due to controlled release of the drug from the GCD nanocarrier. Finally, the induction of the autophagy process supports the potential recycling of DOX with the consequent limitation of its toxic effects. Together, these findings demonstrate that GCD@DOX is a biocompatible drug delivery system able to evade chemoresistance and doxorubicin toxicity.

Recognition and capture ofamyloidbeta (Aβ) is a challenging task for the early diagnosis of neurodegenerative disorders, such as Alzheimer’s disease. Here, we report a novel KLVFF-modified nanomagnet based on magneticnanoparticles(MNP) covered with a non-ionic amphiphilic β-cyclodextrin (SC16OH) and decorated with KLVFFoligopeptidefor the self-recognition of the homologous amino-acids sequence of Aβ to collect Aβ (1–42) peptide from aqueous samples. MNP@SC16OH and MNP@SC16OH/Ada-Pep nanoassemblies were fully characterized by complementary techniques both as solid powders and in aqueous dispersions. Single domain MNP@SC16OH/Ada-Pep nanomagnets of 20–40nm were observed by TEM analysis.DLSand ζ-potential measurements revealed that MNP@SC16OH nanoassemblies owned in aqueous dispersion ahydrodynamic radiusof about 150nm, which was unaffected by Ada-Pep decoration, while the negative ζ-potential of MNP@SC16OH (−40mV) became less negative (−30mV) in MNP@SC16OH/Ada-Pep, confirming the exposition of positively charged KLVFF on nanomagnets surface. The ability of MNP@SC16OH/Ada-Pep to recruit Aβ (1–42) in aqueous solution was evaluated by MALDI-TOF and compared with the ineffectiveness of undecorated MNP@SC16OH and VFLKF scrambled peptide-decorated nanoassemblies (MNP@SC16OH/Ada-scPep), pointing out theselectivityof KLVFF-decoratednanohybridtowards Aβ (1–42). Finally, the property of nanomagnets to extract Aβ inconditioned mediumof cells over-producing Aβ peptides was investigated as proof of concept of effectiveness of thesenanomaterialsas potential diagnostic tools.

The graphene road in nanomedicine still seems very long and winding because the current knowledge about graphene/cell interactions and the safety issues are not yet sufficiently clarified. Specifically, the impact of graphene exposure on gene expression is a largely unexplored concern. Herein, we investigated the intracellular fate of graphene (G) decorated with cyclodextrins (CD) and loaded with doxorubicin (DOX) and the modulation of genes involved in cancer-associated canonical pathways. Intracellular fate of GCD@DOX, tracked by FLIM, Raman mapping and fluorescence microscopy, evidenced the efficient cellular uptake of GCD@DOX and the presence of DOX in the nucleus, without graphene carrier. The NanoString nCounter&trade, platform provided evidence for 34 (out of 700) differentially expressed cancer-related genes in HEp-2 cells treated with GCD@DOX (25 &micro, g/mL) compared with untreated cells. Cells treated with GCD alone (25 &micro, g/mL) showed modification for 16 genes. Overall, 14 common genes were differentially expressed in both GCD and GCD@DOX treated cells and 4 of these genes with an opposite trend. The modification of cancer related genes also at sub-cytotoxic G concentration should be taken in consideration for the rational design of safe and effective G-based drug/gene delivery systems. The reliable advantages provided by NanoString&reg, technology, such as sensibility and the direct RNA measurements, could be the cornerstone in this field.

In this paper, two medusa-like ACyDs, modified at the primary rim bearing four (ACyD4) and eight carbons (ACyD8) acyl chain length, and one bouquet-like CyD, modified at primary side with thiohexyl and at secondary one with oligoethylene moiety (SC6OH), were investigated for their ability to assemble in nanostructures or to form hybrid dipalmitoylphosphatidylcholine (DPPC)/ACyDs systems. The lipophilicity of these molecules and the different preparation methods used in this study (thin layer evaporation and nanoprecipitation method) significantly affect the aggregation behaviour in aqueous medium. Except for the shortest medusa-like ACyD4, the other ACyDs formed stable nanoaggregates for at least 45 days. The effect of ACyDs on the thermotropic behaviour of DPPC liposomes was also studied by differential scanning calorimetry analysis, thus elucidating their interaction with liposomes to afford hybrid liposome/ACyDs systems. The medusa-like ACyD4 cannot be used to realize nanosystems because it quickly aggregates or it induces a complete destabilization of the liposomes. At the highest concentration investigated (0.01 molar fraction), both ACyD8 and SC6OH interacted with DPPC liposomes, forming ACyD/DPPC or SC6OH/DPPC hybrid vesicular carriers.

Nowadays, active targeting of nanotherapeutics is a challenging issue. Here, we propose a rational design of a ternary nanoassembly (SAP) composed of nonionic amphiphilic beta-cyclodextrins (amphiphilic CD) incorporating pheophorbide (Pheo) as a phototherapeutic and an adamantanyl-folic acid conjugate (Ada-FA) to target tumor cells overexpressing alpha-folate receptor (FR-alpha(+)). Dynamic light scattering and zeta-potential pointed out the presence of nanoassemblies bearing a negative surface charge (zeta = -51 mV). Morphology of SAP was investigated by atomic force microscopy and microphotoluminescence, indicating the presence of highly emissive near-spherical assemblies of about 280 nm in size. Complementary spectroscopic techniques such as ROESY-NMR, UV/vis and steady-state fluorescence revealed that the folic acid protrudes out of amphiphilic CD rims, prone for recognition with FR-alpha. Pheo was strongly loaded in the nanoassembly mostly in monomeric form, thus generating singlet oxygen (O-1(2)) and consequentely showing phototherapeutic action. SAP remained stable until 2 weeks in aqueous solutions. Stability studies in biologically relevant media pointed out the ability of SAP to interact with serum proteins by means of the oligoethylenglycole fringe, without destabilization. Release experiments demonstrated the sustained release of Pheo from SAP in environments mimiking physiological conditions (similar to 20% within 1 week), plausibly suggesting low Pheo leaking and high integrity of the assembly within 24 h, time spent on average to reach the target sites. Cellular uptake of SAP was confirmed by confocal microscopy, pointing out that SAP was internalized into the tumoral cells expressing FR-alpha more efficiently than SP. SAP showed improved phototoxicity in human breast MCF-7 cancer cells FR-alpha(+) (IC50 = 270 nM) with respect to human prostate carcinoma PC3 cells (IC50 = 700 nM) that express a low level of that receptor (FR-alpha(-)). Finally, an improved phototoxicity in FR-alpha(+) MCF-7 cells (IC50 = 270 nM) was assessed after treatment with SAP vs SP (IC50 = 600 nM) which was designed without Ada-FA as a targeting unit.

Magnetic nanoparticles (MNPs) are widely utilized in magnetic-field-assisted bio-separation, bio- interaction, imaging and drug delivery, due to their large surface area and easy manipulation by an external magnetic force. MNPs, stabilized with different capping agents and incorporating drugs, were designed as nanotheranostic. In this context, cyclodextrin-based MNPs offer a multipurpose chance in detection, therapy and imaging, since cyclodextrins (CDs) can strongly entrap in its cavity hydrophobic guests to optimize molecular recognition of biomarkers or for sustained therapeutic action in the site where they are directed with the help of the magnetic field and / or serving as contrast agents in magnetic resonance imaging (MRI) . Amphiphilic cyclodextrin (aCD) are efficaciously engaged to entrap and control deliver of drugs and diagnostic probes [1]. Here we propose MNP covered with aCD nanomagnets (aCD is heptakis (2-oligo(ethyleneoxide)-6-hexadecylthio-)-?- CD (SC16OH)) (MNP@SC16OH) and tailored with Adamantanil-(PEG)4-KLVFF (Ada-Pep) for recognition and detection of Amyloid-?(1-42) protein (A?(1-42)). MNP@SC16OH/Ada-Pep were prepared by hydration of an organic film of Ada-Pep with a dispersion of pre-made-up MNP@SC16OH. Hence, modified MNPs were isolated by magnetic-filed separation, centrifugation and fully characterized [2]. Furthermore, we investigated the ability of system to fish out A?(1-42) from samples prepared in aqueous solutions and analysed by MALDI-TOF MS. Our results indicate that in our experimental conditions the nanomagnets can perform an unbiased A?(1-42)-targeted fishing. Moreover the effect of nanomagnetes in delivery of anticancer drugs as sorafenib in hepatocellular carcinoma (HCC) cells as well as in in vitro enhancement of MRI relaxivity was investigated [3]. Altogether, results indicate the potential utilize of these nanomagnets based on cyclodextrins as therapeutic and imaging agents.

The development of functional supramolecular polymers, that readily self-assemble in aqueous media into structurally stable nanoconstructs with high drug loading capacity and controlled drug release ability under different environmental conditions, has recently attracted considerable attention as an efficient strategy to improve the efficiency of current drug delivery systems.1 Nanoscale polymer vehicles based on Hyaluronic Acid (HA) and poly-Cyclodextrin (CD) are very promising transport systems for delivering chemotherapeutic and biological drugs due to their aqueous solubility, low toxicity or immunity and supramolecular self-assembly ability after chemical modification. Here we describe the supramolecular nanoassemblies obtained by HA functionalized with ?-CD2 and by cationic-cyclodextrin polymer. Their drug binding abilities have been investigated by complementary spectroscopic techniques including UV-Vis, ?-potential and DLS, using acyclovir and diclofenac as model drugs.

Injectable hydrogels continue to gain interest as scaffolds for biomolecule/drug delivery and tissue engineering due to their potential for minimally invasive administration and tunability in properties. In recent years, they have seen a continueous advance and creativity in their design, fabrication and application areas. In order to maximize their resemblance with the cellular microenvironment they're made of biocompatible and versatile bio-polymers that can be modified by introducing various functional sites. Currently, we are exploring the best experimental conditions to obtain a hydrogel scaffold formed by the supramolecular interaction between different polymer networks (i.e. hyaluronic acid and a cationic poly-cyclodextrin) using a bifunctional adamantanyl cross- linker agent. Thus, the tridimensional interconnected nanoassemblies can incorporate, even thanks to the presence of CD cavities, therapeutic cargos (i.e. FANS), diagnostic probes, growth and adhesion factors, exosomes and other cell-derived materials

Osteoarthritis is one of the most widespread diseases worldwide, with a progressive damage to cartilage and bone. In this context, the choice of biocompatible materials mimicking the cellular microenvironment is of the utmost importance to develop new drug carriers. Cyclodextrins (CDs) and hyaluronic acid (HA) are promising candidates for intra-articular injection in the joint synovial fluid because of the high biocompatibility and effectiveness of HA, empowered by the presence of the CD units able to entrap therapeutic agents for the regenerative process. Nano and micro scale polymeric assemblies based on cationic ?-CD polymers (PolyCDNH3+ or PolyCDNR3+) and HA have been developed by using both supramolecular and/or covalent approaches. Supramolecular nanoassemblies made from PolyCDNH3+ were obtained by using a crosslinker bearing two terminal adamantane moieties. Spongy hydrogels based on PolyCDNR3+/HA were prepared through amide formation. The nanoassemblies were loaded with fluorescent probe, with diclofenac and were characterized by complementary spectroscopic techniques including 1H-NMR, UV-Vis, steady-state and time-resolved fluorescence, DLS and ?-potential measurement. Release profiles were investigated in vitro in media mimicking the physiological conditions to ensure control over time and efficacy. Biocompatibility studies were performed by placing primary human bone marrow-derived mesenchymal stromal cells in contact with the nanosystems and testing cell viability by WST-1 assay. With these premises, this study might open novel routes to exploit original CD-based nanobiomaterials for OA treatment.

In the past few years, extensive research has been done to develop proper drug delivery platforms that can deliver therapeutic agents to specific sites of the body or targeted cells, minimizing side effects. Similar to the microenvironment of soft tissues, hydrogels are a novel type of delivery platform with a 3D interconnected structure formed by physically or chemically cross-linked polymer networks. Drugs can be incorporated in the tridimensional scaffold and successfully vehiculated/administered into specific sites of the organism1. Hyaluronic acid (HA) is a high molecular weight negatively charged polysaccharide composed of repeating disaccharide units, which is abundant in the synovial fluid and extracellular matrix, but has also been found intracellularly. HA is involved in several biological processes such as the maintenance of the viscoelasticity of connective fluids, tissue hydration, morphogenesis and cell repair2. For these reasons it represents a valid biomaterial for tissue engineering as component of hydrogel platforms, thanks further to its good biocompatibility, biodegradability and non-immunogenicity. Currently, we are exploring the best experimental conditions to obtain a hydrogel scaffold formed by the interactions between an amphiphilic network (HA-TDA) and a cationic cyclodextrin polymer (Poly-CD). Once formed, the construct can potentially incorporate various therapeutic cargos (i.e. drugs, growth factors, exosomes, cell adhesion promoters) and diagnostic probes (i.e. fluorophores and magnetic nanoparticles), to be used as cell-laden material for bioprinting in regenerative medicine applications3. HA-TDA was synthesized by coupling of hydrophobic tetradecylamine (TDA) to hyaluronic acid (HA) in the presence of 2-chloro-4,6-dimethoxy-2,3,5-triazine (CDMT) and N-methylmorpholine (NMM). Complementary spectroscopic techniques such as UV-Vis, steady-state and time-resolved fluorescence, DLS and z-potential measurement have been used to investigate the interactions and to monitor the assembly between HA-TDA and Poly-CD at different mass ratios and the entrapment capability of HA@CD assembly.

In the development of new antibacterial therapeutic approaches to fight multidrug-resistant bacteria, antimicrobial photo dynamic therapy (aPDT) represents a well-known alternative to treat local infections caused by different microorganisms. Here we present a polypropylene (PP) fabric finished with citrate-hydroxypropyl-beta CD polymer (PP-CD) entrapping the tetra-anionic 5,10,15,20-tetrakis(4-sulfonatophenyl)-21H,23H-porphine (TPPS) as photosensitizer-eluting scaffold (PP-CD/TPPS) for aPDT. The concept is based on host-guest complexation of porphyrin in the cavities of CDs immobilized on the PP fibers, followed by its sustained and controlled delivery in release medium and simultaneous photoinactivation of microorganisms. Morphology of fabric was characterized by optical (OM) and scanning electron microscopies (SEM). Optical properties were investigated by UV-vis absorption, steady- and time-resolved fluorescence emission spectroscopy. X-ray photoelectron spectroscopy (XPS) and FT-IR revealed the surface chemical composition and the distribution map of the molecular components on the fabric, respectively. Direct O-1(2) determination allowed to assess the potential photodynamic activity of the fabric. Release kinetics of TPPS in physiological conditions pointed out the role of the CD cavity to control the TPPS elution. Photoantimicrobial activity of the porphyrin-loaded textile was investigated against both Gram-positive Staphylococcus aureus ATCC 29213 (S. aureus) and Gram-negative Pseudomonas aeruginosa ATCC 27853 (P. aeruginosa). Optical microscopy coupled with UV vis extinction and fluorescence spectra aim to ascertain the uptake of TPPS to S. aureus bacterial cells. Finally, PP-CD/TPPS fabric-treated S. aureus cells were photokilled of 99.98%. Moreover, low adhesion of S. aureus cells on textile was established. Conversely, no photodamage of fabric-treated P. aeruginosa cells was observed, together with their satisfying adhesion.

Complexes of cationic amphiphilic cyclodextrins heptakis[2-(ω-amino-oligo(ethylene glycol))-6-deoxy-6-hexadecylthio]-β-cyclodextrin and heptakis[2-(ω-amino-oligo(ethylene glycol))-6-deoxy-6-dodecylthio]-β-cyclodextrin with DNA were examined by small-angle X-ray scattering and dynamic as well as electrophoretic light scattering. The first cyclodextrin forms bilayer vesicles in water, which, in the presence of calf thymus DNA, transform to a multilamellar complex. In this complex, the DNA lies between the two polar layers of the cyclodextrin's protonated amino groups in alternation with the lipidic bilayers. The cyclodextrin with shorter lipid chains, in contrast, forms micelles in water, and electrostatic clustering of these about DNA does not affect their intrinsic structure. These results are relevant to the potential of such cyclodextrins in therapeutic gene delivery, showing that their self-assembly modes in isolation influence their complex formation with DNA and possibly their efficiency in promoting cell transfection.

Cyclodextrin are suitable host molecules especially used for drug entrapment and delivery. Our goals is to design and characterize biodegradable amphiphilic cyclodextrin able to host, deliver and especially target a drug in the sites of action. These carriers, have a size compatible with i.v. injection and posses high potential to optimize drug distribution in the body, and selectively deliver anticancer [1,2], photosensitiser for Photodynamic Therapy of Tumors (PDT) [3], metal nanoparticles [4], DNA for gene therapy [5 ] or combined dose of therapeutics [6] and /or diagnostic probe for theranostic [7].This multifunctional nanoconstructs can be engineered with stimuli-responsive probes i.e. pH, magnetic field, light , redox potential [8], or combined with nanoplatform based on graphene and/or MWCNT [9] to give dispositives for investigating cell behavior. Recent investigations and results will be here discussed.

The combination of conventional anticancer therapy with other treatment modalities such as photodynamic therapy (PDT) is paving the way to novel more effective treatment of solid tumors via light exposure. With this idea in mind, in this paper, nanoparticles (NPs) based on Heptakis (2-oligo(ethyleneoxide)-6-hexadecylthio-)-beta-CD (SC160H) for dual delivery of Zinc-Phthalocyanine (ZnPc) and Docetaxel (DTX) were developed pointing to their potential application as nanomedicine for the combined photodynamic and chemo-therapy of solid tumors. NPs prepared by the emulsion -solvent evaporation technique displayed a hydrodynamic diameter of congruent to 200 nm, a negative zeta potential (cAt 27 mV) and a satisfactory entrapment efficiency of both drugs at a specific mass ratio. On these bases, NPs containing DTX and ZnPc with theoretical loading of 5% and 0.2% respectively (ZnPc/DTX5-NPs) were selected for further investigations. The allocation of ZnPc and DTX into the colloid was investigated by complementary spectroscopic techniques. In particular, fluorescence emission studies showed the entrapment of ZnPc as a monomer in the carrier, with a low tendency to self -aggregate and consequently a fairly high propensity to photogenerate singlet oxygen. The interaction of SC160H with DTX, co-entrapped with ZnPc, was elucidated by 1H NMR and 2D ROESY, which suggested the presence of the chemotherapeutic in the hydrophobic portion of SC160H. ZnPc/DTX5-NPs were fairly stable in different biological relevant media within 24h. Finally, in vitro potential of the nanoassembly was evaluated in HeLa cancer cells by cell viability exploring both effects of DTX and ZnPc. Overall, results suggest the suitability of NPs based on SC16OH for delivering a combination of DTX with ZnPc to cancer cells, thus inducing photodynamic and antimitotic effects. (C) 2016 Elsevier B.V. All rights reserved.

Supplement to Biomacromolecules 2015, 16, 3784-3791 Abstract: Sorafenib (Sor), an effective chemiotherapeutic drug utilized against hepatocellular carcinoma (HCC), robustly interacts with nonionic amphiphilic cyclodextrin (aCD, SC6OH), forming, in aqueous solution, supramolecular complexes that behave as building blocks of highly water-dispersible colloidal nanoassemblies. SC6OH/Sor complex has been characterized by complementary spectroscopic techniques, such as UV-vis, steady-state fluorescence and anisotropy, resonance light scattering and 1H NMR. The spectroscopic evidences and experiments carried out in the presence of an adamantane derivative, which competes with drug for CD cavity, agree with the entrapment of Sor in aCD, pointing out the role of the aCD cavity in the interaction between drug and amphiphile. Nanoassemblies based on SC6OH/Sor display size of ~200 nm, negative zetapotential (? = -11 mV), and both maximum loading capacity (LC ~ 17%) and entrapment efficiency (EE ~ 100%). Kinetic release profiles show a slower release of Sor from nanoassemblies with respect to the free drug. SC6OH/Sor nanoassemblies have very low hemolytic activity and high efficiency in vitro in decreasing cell growth and viability of HCC cell lines, such as HepG2, Hep3B, and PLC/PRF/5, opening promising chances to their in vivo applications. PMID: 26528591

Amphiphilic beta-cyclodextrins have been synthesized bearing hexylthio, dodecylthio, and hexadecylthio chains at the 6-positions and glycosylthiocarbamoyl-oligo(ethylene glycol) units at the 2-positions. The glycosyl residues (alpha-D-mannosyl and beta-L-fucosyl) are intended for cell-targeting. Self-assembly of these new amphiphilic glycosylated cyclodextrins in water to form vesicles was investigated by dynamic light scattering and transmission electron microscopy. Selective binding of the hexylthio assemblies to a protein receptor (Lens culinaris lectin) was confirmed by fluorescence spectroscopy.

Sorafenib (Sor), an effective chemiotherapeutic drug utilized against hepatocellular carcinoma (HOC), robustly interacts with nonionic amphiphilic cyclodextrin (aCD, SC6OH), forming, in aqueous solution, supramolecular complexes that behave as building blocks of highly water-dispersible colloidal nanoassemblies. SC6OH/Sor complex has been characterized by complementary spectroscopic techniques, such as UV-vis, steady-state fluorescence and anisotropy, resonance light scattering and H-1 NMR. The spectroscopic evidences and experiments carried out in the presence of an adamantane derivative, which competes with drug for CD cavity, agree with the entrapment of Sor in aCD, pointing out the role of the aCD cavity in the interaction between drug and amphiphile. Nanoassemblies based on SC6OH/Sor display size of similar to 200 nm, negative zeta-potential (zeta = -11 mV), and both maximum loading capacity (LC similar to 17%) and entrapment efficiency (EE similar to 100%). Kinetic release profiles show a slower release of Sor from nanoassemblies with respect to the free drug. SC6OH/Sor nanoassemblies have very low hemolytic activity and high efficiency in vitro in decreasing cell growth and viability of HOC cell lines, such as HepG2, Hep3B, and PLC/PRF/5, opening promising chances to their in vivo applications.

A range of chemically modified amphiphilic cyclodextrins has been synthesized with the aim of providing versatile carrier and delivery systems for drug molecules. Amphiphilic cyclodextrins combine the properties of macrocyclic hosts and self-organizing amphiphiles An adequate balance between hydrophobic tails and hydrophilic heads is required for the preparation of equilibrium systems of amphiphilic cyclodextrins in acqueous solutions. In our case the introduction of hydrophilic oligo(ethylene glycol) onto the secondary side of heptakis(6-deoxy-6-alkylthio)-beta -cyclodextrins results in the formation of amphiphilic macrocycles with dramatically increased water solubility. In this paper we describe the properties of aqueous solutions of heptakis[6-alkylthio-6-deoxy-2-oligo(ethylene glycol)]-beta-cyclodextrins where alkyl is ethyl or hexyl. Our study compares three compounds with a different balance of hydrophobic alkyl substituents at C6 and hydrophilic oligo(ethylene glycol) substituents at C2.

Amphiphilic cyclodextrin (ACyD) provides water-soluble and adaptable nanovectors by modulating the balance between the hydrophobic and hydrophilic chains at both CyD sides. This work aimed to design nanoassemblies based on nonionic and hydrophilic ACyD (SC6OH) for the delivery of a poor-water-soluble organotin(IV)-porphyrin derivative [(Bu3Sn)4TPPS] to melanoma cancer cells. To characterize the porphyrin derivatives under simulated physiological conditions, a speciation was performed using complementary techniques. In aqueous solution (≤ 20 μM), (Bu3Sn)4TPPS primarily exists as a monomer (2 in Figure 1), as suggested by the low static anisotropy (ρ ≈ 0.02) with a negligible formation of porphyrin supramolecular aggregates. MALDI-TOF spectra indicate the presence of moieties (i.e., [(Bu3Sn)3TPPS](-)) that are derivatives of the monomeric species. Spectrofluorimetry coupled with potentiometric measurements primarily assesses the presence of the hydrolytic [(Bu3Sn)4TPPS (OH)4](4-) species under physiological conditions. Nanoassemblies of (Bu3Sn)4TPPS/SC6OH were prepared by dispersion of organic films in PBS at pH 7.4 and were investigated using a combination of spectroscopic and morphological techniques. The UV-vis and emission fluorescence spectra of the (Bu3Sn)4TPPS/SC6OH reveal shifts in the peculiar bands of the organotin(IV)-porphyrin derivative due to its interaction with the ACyD supramolecular assemblies in aqueous solution. The mean size was within the range of 100-120 nm. The ξ-potential was negative (-16 mV) for the (Bu3Sn)4TPPS/SC6OH nanoassemblies, with an entrapment efficiency of approximately 67%. The intracellular delivery, cytotoxicity, nuclear morphology and cell growth kinetics were evaluated via fluorescence microscopy on A375 human melanoma cells. The delivery of (Bu3Sn)4TPPS by ACyD with respect to free (Bu3Sn)4TPPS increases the internalization efficiency and cytotoxicity to induce apoptotic cell death and, at lower concentrations, changes the cellular morphology and prevents cell proliferation.

We have developed a supramolecular nanoassembly capable of inducing remarkable levels of cancer cell mortality through a bimodal action based on the simultaneous photogeneration of nitric oxide (NO) and singlet oxygen ((1)O(2)). This was achieved through the appropriate incorporation of an anionic porphyrin (as (1)O(2) photosensitizer) and of a tailored NO photodonor in different compartments of biocompatible nanoparticles based on cationic amphiphilic cyclodextrins. The combination of steady-state and time-resolved spectroscopic techniques showed the absence of significant intra- and interchromophoric interaction between the two photoactive centers embedded in the nanoparticles, with consequent preservation of their photodynamic properties. Photodelivery of NO and (1)O(2) from the nanoassembly on visible light excitation was unambiguously demonstrated by direct and real-time monitoring of these transient species through amperometric and time-resolved infrared luminescence measurements, respectively. The typical red fluorescence of the porphyrin units was essentially unaffected in the bichromophoric nanoassembly, allowing its localization in living cells. The convergence of the dual therapeutic action and the imaging capacities in one single structure makes this supramolecular architecture an appealing, multifunctional candidate for applications in biomedical research.

Nanoggregates of nonionic amphiphilic cyclodextrin (ACyD) modified with hydrophobic chains of intermediate length [(2-oligo-ethyleneoxide-6-hexylthio)-beta-CyD, SC6OH] were prepared by emulsification-diffusion method. They are able to entrap an isoflavone, genistein (Gen), and the complexed species are studied at different host/guest molar ratio. The increased isoflavone solubility in the presence of the aggregates of SC6OH is investigated by UV-Vis spectroscopy, whereas size, charge, and structure of aggregates and their complexes with Gen are measured by means of static and quasi-elastic light scattering, and electrophoretic mobility measurements. On the other hand, preparing samples by the conventional method used for liposomes (hydration of an organic film of SC6OH and sonication) gives rise to aggregates with different sizes and lower colloidal stability. It is shown that the improved stability in water of ACyD aggregates both in the absence and in the presence of Gen, obtained by emulsification-diffusion is due to the existence of nanodomains of organic solvent (R(H) congruent with 120 nm) which cannot be completely removed by evaporation and freeze-drying and in which host/guest complexes are contained. This result shows that residues of organic solvent from preparation step favor the colloidal stability of the aggregate, but their presence must be taken into account in designing systems for drug delivery.

The engineering of multifunctional nanoparticles carrying photosensitizer drugs (PS) and exposing binding groups for cellular receptors is of increasing interest in therapeutics and diagnostics applications. Natural and modified cyclodextrins (CDs) offer useful scaffolds to bind PS guests by supramolecular interactions. In particular, amphiphilic β-CDs, which form nanoaggregates of diverse shape and size according to the polarity of substituent groups on the rims, include in their different compartments as CD cavity, hydrophilic and hydrophobic portion, PS with different physicochemical properties. PS embedded in cationic amphiphilic CD nanoassemblies are effective in inducing photodynamic damage in cancer cells. For a carrier/PS system to be used in photodynamic therapy (PDT) or photodynamic diagnosis (PDD), the appropriate combination of the delivery characteristics with the preservation of the photodynamic activity of the PS is strictly required. Homogeneous multilayer films based on cationic amphiphilic β-CD entrapping anionic porphyrins can be constructed to exploit interfacial electrostatic interactions between the two components. The capability of CDs to generate restricted microenvironments for PS which can facilitate photoinduced energy transfer with suitable donor molecules was investigated for potential application in fluorescence diagnosis. Besides, recent findings suggest that PDT could represent a useful tool for properly addressing an alternative approach for killing pathogens and combating infections at a clinical level. Finally, modified CDs can bind gold nanoparticles, yielding hybrid organic/inorganic nanoparticles which were studied in water solution and after casting on solid substrates. These binary assemblies could further encapsulate PS or other conventional drugs, opening new intriguing routes on multimodal therapy.

The aim of this study was to develop nanoparticles made of the amphiphilic cyclodextrin heptakis (2- O -oligo(ethyleneoxide)-6-hexadecylthio-)-β-CD (SC16OH) entrapping docetaxel (Doc) and establish their in vivo potential. Doc-loaded SC16OH nanoparticles were prepared by the emulsion–solvent evaporation technique and fully characterized for size, zeta potential, amount of entrapped drug, release rate and degradation rate. Spherical vesicular nanoparticles displaying a hydrodynamic radius of about 95 nm which did not change upon storage as an aqueous dispersion, a negative zeta potential and entrapment efficiency of Doc very close to 100% were produced. DSC study highlighted the crystalline nature of SC16OH, unloaded and Doc-loaded SC16OH nanoparticles which resulted in their very slow dissolution during release stage and well-modulated release of entrapped Doc for about 8 weeks. Doc-loaded SC16OH nanoparticles were not hemolytic toward red blood cells as compared to a commercial Doc formulation (Taxotere ® ) which shows a dose-dependent toxicity. After exposure of HEp-2 cells to equivalent doses of free Doc and Doc-loaded SC16OH nanoparticles, superior cell killing and cell damage were observed for nanoparticles. Finally, cell damage was attributed to aberrant mitosis which was found to be significantly higher for HEp-2 cells treated with Doc-loaded SC16OH nanoparticles as compared to free Doc likely due to the ability of nanoparticles to slowly release the drug allowing prolonged cell arrest in mitosis. Taken together, these results highlights a great potential of nanoparticles based on SC16OH in solid tumors therapy.

Recent findings suggest that visible light-promoted photooxidative processes mediated by sensitizers of appropriate chemical structure could represent a useful tool for properly addressing the problem of the increasing occurrence of infectious diseases caused by multiantibiotic-resistant microbial pathogens. The monocationic meso-substituted porphyrin 5-[4-(1-dodecanoylpyridinium)]-10,15,20-triphenyl-porphine (TDPyP) complexed into supramolecular aggregates of cationic amphiphilic beta-cyclodextrin (SC(6)NH(2)) (mean diameter = 20 nm) appeared to be endowed with favorable properties to act as a photosensitizing agent, including a very high quantum yield (Phi(Delta) = 0.90) for the generation of the highly reactive oxygen species, singlet oxygen ((1)O(2)). Although the yield of (1)O(2) generation was comparable to that obtained after TDPyP incorporation into cationic unilamellar liposomes of N-[1-(2,3-dioleoyloxy)propyl]-N,N,N-trimethylammonium chloride (DOTAP) SC(6)NH(2)-bound TDPyP was more active than DOTAP-bound TDPyP in photosensitizing the inactivation of the Gram-positive methicillin-resistant bacterium Staphylococcus aureus (MRSA). At variance with DOTAP-bound TDPyP, photoactivated SC(6)NH(2)-bound TDPyP was efficient also in photokilling Gram-negative bacterial pathogens, such as Escherichia coli . These observations are in agreement with the well-known photobactericidal effect of positively charged porphyrin derivatives, which can be markedly enhanced after incorporation into carriers with multiple positive charges. In addition, transmission electron microscopy studies revealed that potentiation of the TDPyP-mediated photobactericidal effect by incorporation into SC(6)NH(2) is a consequence of the carrier's ability to promote an efficient crossing of the very tightly organized three-dimensional architecture of the bacterial outer wall by the embedded porphyrin so that a prompt interaction between the short-lived photogenerated (1)O(2) and the nearby targets, whose integrity is critical for cell survival, can take place.

The improvement of isoflavones bioavailability by complexation with chemically modified cyclodextrins (CyDs) has been exploited to analyse the drug/macrocycle binding affinity by a conventional method with new useful measures. Genistein (Gen) and daidzein (Daidz) were investigated in aqueous medium and in presence an amount of (2-hydroxypropyl)-beta-cyclodextrin (HP-beta-CyD) at different host/guest molar ratios. The solubility in pure water, approximately 3 x 10(-6)M for Gen and approximately 10 x 10(-6)M for Daidz, was obtained by distributing the of guest molecule between water and the organic solvent. The stoichiometric ratios and stability constants describing the extent of formation of the complexes have been determined by phase-solubility UV-vis measurements and confirmed by circular dichroism data. These results have implications in the determination of the carrier's capacity for the complexation of the drug in water solution.

The photodynamic activity of a carrier-sensitizer system consisting of heterotopic colloidal nanoparticles (diameter 100–1000 nm) of a cationic amphiphilic cyclodextrin, heptakis(2-ω-amino-O-oligo(ethylene oxide)-6-hexylthio)-β-CD (SC6CDNH2) encapsulating the anionic 5,10,15,20-tetrakis(4-sulfonatophenyl)-21H,23H-porphyrin (TPPS) is investigated by an interdisciplinary approach involving the combination of time-resolved absorption and emission techniques with in vitro studies on cultured tumor cells. In a range of TPPS:SC6CDNH2 molar ratios between 1:10 and 1:50 these nanoparticles preserve the photodynamic properties of the entrapped photoactive agent. In fact, the triplet state of TPPS is efficiently populated, very long-lived and, as a consequence, able to produce singlet oxygen (the essential species for the photodynamic action) with quantum yield comparable to the free TPPS. Photodynamic efficacy of the carrier/sensitizer system is proven by in vitro studies on tumor Hela cells treated with TPPS:SC6CDNH2 at different molar ratio, showing significant cells death upon illumination with visible light.

The interaction between the anionic 5,10,15,20-tetrakis(4-sulfonatophenyl)-21H,23H-porphyrin (TPPS) and cationic vesicles formed by heptakis(2-omega-amino-O-oligo(ethylene oxide)-6-hexylthio)-beta-cyclodextrin (SC6CDNH2) has been investigated in detail through a combination of elastic light scattering (ELS), quasi-elastic light scattering (QELS), zeta potential measurements, and time-resolved fluorescence anisotropy. ELS experiments provided the first structural characterization of these cationic vesicles both in the absence and in the presence of TPPS porphyrin, modeling the system as a spherical particle described by a single thin shell form factor. The structure of mixed hetero-aggregates is modulated by charge and size of the two components as function of different porphyrin/cyclodextrin (CD) molar ratios. At the limiting molar ratio studied, the absolute value of zeta potential (/zeta/ = 12.5 mV) seems to be a reference value for the formation of stable colloidal CD vesicular aggregates at thermodynamic equilibrium. New insights on the structure of these heterotopic colloids have been obtained by analysis of rotational correlation times at different molar ratios exploiting time-resolved fluorescence anisotropy experiments. At high porphyrin loads, the anisotropy decays behave as monoexponentials and the rotational correlation times (1-2 ns) together with the r(0) values close to zero suggest the presence of small amounts of TPPS embedded in a hydrophobic environment either in monomeric or in aggregated form. At the lower porphyrin/CD molar ratios, the anisotropy decays exhibit a double-exponential behavior showing a predominant component with a slow rotational correlation time (20-25 ns) and limiting anisotropy values of approximately 0.15. This component has been assigned to molecules that are more stabilized onto the CD vesicles, that is, porphyrins embedded into the oligo-ethylene "wall" of the CD vesicles. Scanning near-field optical microscopy of the samples evaporated on glass surfaces gave further insights on the morphology and optical properties of these systems, confirming the embedding of TPPS on the vesicles and evidencing the role of the solvent.

Amphiphilic beta-cyclodextrins with alkylthio chains at the primary-hydroxyl side and galactosylthio-oligo-(ethylene glycol) units at the secondary-hydroxyl side, which form nanoparticles and vesicles, show multivalent effects in their binding to lectin.

An emitting nanoassembly composed of a novel amphiphilic cyclodextrin functionalised with a covalently appended fluorophore and an anionic porphyrin internalizes effectively in tumor cells, allowing simultaneously the detection of carrier and photosensitiser.

The separation of three pairs of enantiomeric herbicides has been successfully achieved by capillary electrophoresis at two different pH values in the presence of cyclodextrin derivatives previously synthesized in our laboratory. Two of these derivatives constitute a new class of receptor, the hemispherodextrins, in which a trehalose capping moiety is bonded to beta-cyclodextrin. Because of their peculiar structure hemispherodextrins have very promising characteristics and the low receptor concentration required to achieve separation deserves particular interest.