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A novel star-shaped amphiphilic copolymer based on three poly(lactide)-block-poly(ethylene glycol) (PLA-PEG) terminal arms extending from a glycerol multifunctional core was newly synthesized and decorated with the tumor-targeting ligand cyclic-RGDyK peptide (Arg-Gly-Asp-D-Tyr-Lys) to be eventually formulated in polymeric micelles incorporating a suitable anticancer drug (i.e., Docetaxel, DTX; drug loading 16 %, encapsulation efficiency 69 %). The biological profile of unloaded micelles (RGD-NanoStar) was studied on Human Adipose-derived Mesenchymal Stem Cells (Ad-MSCs) as health control, pointing out the absence of toxicity. Surprisingly, an unprecedented effect on cell viability was exerted by RGD-NanoStar, comparable to that of the free DTX, on tumoral MDA-MB 468 Human Breast Adenocarcinoma cells, specifically starting from 48 h of culture (about 40 % and 60 % of dead cells at 48 and 72 h, respectively, at all tested concentrations). RGD-NanoStar reduced the cell viability also of tumoral U87 Human Glioblastoma cells, compared to cells only, at 72 h (about 25 % of dead cells) demonstrating a time-dependent effect exerted by the highest concentrations. The effects of DTX-loaded micelles (RGD-NanoStar/DTX) on U87 and MDA-MB 468 cell lines were evaluated by MTT, cell morphology analysis, and scratch test. A compromised cell morphology was observed without significant difference between DTX-treated and RGD-NanoStar/DTX - treated cells, especially in U87 cell line. Although no apparent benefit emerged from the drug incorporation into the nanosystem by MTT assay, the scratch test revealed a statistically significant inhibition of tumoral cell migration on both cell lines, confirming the well-known role of DTX in inhibiting cell movements even when loaded on polymeric micelles. Specifically, only 43 μm distance was covered by U87 cells after 30 h culture with RGD-NanoStar/DTX (30 μg/mL) compared to 73 μm in the presence of free DTX at the same concentration; more interestingly, a total absence of MDA-MB 468 cell movements was detected at 30 h compared to about 50 μm distance covered by cells in the presence of free DTX (10 μg/mL). The stronger inhibitory activity on cell migration of RGD-NanoStar/DTX compared to the free drug in both cell lines at 30 h attested for a good ability of the drug-loaded nanocarrier to reduce tumor propagation and invasiveness, enhancing the typical effect of DTX on metastatization.

Functionalized carbon nanotubes (CNTs) have been proposed in the last years as vectors for delivery of biomolecules, proteins and DNA into various cells. In this study, a new multiwalled carbon nanotube β-cyclodextrin platform (MWCNT-CD) modified with branched polyethylenimine (PEI) and doped with Rhodamine (Rhod), MWCNT-CD-PEI-Rhod, was designed and investigated as drug delivery system. The drug binding abilities of MWCNT-CD-PEI-Rhod towards Cidofovir (Cid) and DNA plasmid encoding enhanced green fluorescence protein (pCMS-EGFP) were investigated by complementary spectroscopic techniques. MWCNT-CD-PEI-Rhod showed no significative cytotoxicity and an excellent ability to entrap and delivery Cid. The present study broadens the spectrum of biological evaluation by investigating platform-treatment induced cellular response such as antiviral activity, transfection properties, cellular uptake, internalization mechanisms and cellular localization. The mechanism of cellular uptake was elucidated monitoring the dependence of intracellular red fluorescence from the assembly concentration, time and presence of specific uptake inhibitors. The biological results indicated that MWCNT-CD-PEI-Rhod loaded with Cid and/or pCMS-EGFP crossed the cell membrane via clathrin-dependent pathway and co-localized in lysosomal compartment. However, no green fluorescent protein expression of pCMS-EGFP was detected, whereas the efficient escape of Cid from lysosome and the release close to nuclear region prompted the antiviral activity.

We report a hybrid nanoassembly based on gold colloids decorated with a new thiolated amphiphilic cyclodextrin complexing dopamine (AuNPs@SC16SH/DA). The novel amphiphilic β-cyclodextrin SC16SH, bearing on average one thiol group at the end of an oligoethylene glycol chain per CyD unit, was obtained in a multi-step synthesis and fully characterized by NMR spectroscopy and MALDI analysis. The AuNPs@SC16SH hybrid assembly was prepared by mixing AuNPs and SC16SH in aqueous solution and investigated by UV/Vis and TEM measurements. The AuNPs@SC16SH/DA supramolecular assembly, bearing both thiol-stabilized gold nanoparticles and the neurotransmitter dopamine, has been conceived as stimuli-responsive delivery system able to control the release of dopamine upon proper stimuli. Two redox functionalities (i.e. the Au-S bond and the redox behaviour of dopamine) have been exploited to detach SC16SH/DA complex from the AuNPs@SC16SH/DA progenitor platform, using dithiothreitol (DTT), and to detect the complex by cyclic voltammetry (CV). Following, dopamine was finally released from the SC16SH/DA assembly upon treatment with Brij® S20 and the free dopamine was monitored by CV. Overall, our hybrid nanoassemblies turned out to be able to release dopamine, upon combined action of redox and digestion agents in medium emulating biological environment.

Graphene and its multifunctional derivatives may offer passive targeting toward tumor sites and could be designed as drug delivery systems. Surface modifications of graphene materials convey specific biological activity to themselves and improve their biocompatibility. Herein we report the conjugation of Silibinin, a flavonoid employed mainly as hepatoprotective and anticancer agent, to a graphene modified nanoplatform. The cytotoxicity of the new platform has been evaluated on human mesenchymal stem cells and the anticancer effects have been studied on a human osteosarcoma cell line. Our graphene nanoplatform did not show any cytotoxicity even at high concentration (1000 μg/ml) and Silibinin grafted onto graphene maintained its antiproliferative activity.

Nowadays, novel less-expensive nanoformulations for in situ-controlled and safe delivery of photosensitisers (PSs) against opportunistic pathogens in body-infections areas need to be developed. Antimicrobial photodynamic therapy (aPDT) is a promising approach to treat bacterial infections that are recalcitrant to antibiotics. In this paper, we propose the design and characterization of a novel nanophototherapeutic based on the trade cyclodextrin CAPTISOL® (sulfobutylether-beta-cyclodextrin, SBE-βCD) and 5,10,15,20-tetrakis(1-methylpyridinium-4-yl)porphine tetrakis(p-toluenesulfonate) (TMPyP) to fabricate efficient biocompatible systems for aPDT. Spherical nanoassemblies of about 360 nm based on CAPTISOL®/TMPyP supramolecular complexes with 1:1 stoichiometry and apparent equilibrium binding constant (Kb ≅ 1.32 × 105 M−1) were prepared with entrapment efficiency of ≅ 100% by simple mixing in aqueous media and freeze-drying. These systems have been characterized by complementary spectroscopy and microscopy techniques. Time resolved fluorescence pointed out the strong interaction of porphyrin monomer within nanoassemblies (τ2 ≅ 11 ns with an amount of ca 90%) and scarce self-aggregation of porphyrins have been observed. Singlet oxygen comparative determination (ϕΔ CAPTISOL®/TMPyP = 0.58) assessed their photodynamic potential. Release and photostability studies have been carried out under physiological conditions pointing out the role of CAPTISOL® to sustain porphyrin release for more than 2 weeks and to protect PS from photodegradation. Finally, photoantimicrobial activity of nanoassemblies vs free porphyrin have been investigated against Gram-negative P. aeruginosa, E. coli and Gram-positive S. aureus. The proposed nanosystems were able to photokill both Gram-positive and -negative bacterial cells similarly to TMPyP at MBC90 = 6 µM of TMPyP and at 42 J/cm2 light dose. However, with respect to the less selective free TMPyP in biological sites, nanoassemblies exhibit sustained release properties and a higher photostability thus optimizing the PDT effect at the site of action. These results can open routes for in vivo translational studies on nano(photo)drugs and nanotheranostics based on less expensive formulations of CD and PS.

Specific recognition of cell-targeting systems as host-carriers modified with receptor targeting groups, is a major ambition in the application of supramolecular science to medicine and life science. Genistein (Gen), an isoflavone belonging to the class of phytoestrogens, is of great interest because it has been considered as potential remedy for many kinds of disease. In this work, Genistein in aqueous medium and in the presence of an host nanocarrier as amphiphilic cyclodextrin (CyD) modified in the upper rim with oligoethylene hydroxyl groups [(2-oligo(ethyleneoxide)-6-hexylthio)-β-CyD, SC6OH] at 1:1 molar ratio, has been firstly investigated by UV–vis measurements coupled with circular dichroism data, in order to characterize the drug/macrocycle binding affinity through the formation of the complex. Furthermore, FTIR–ATR technique has been used to detect the complex formation in solid phase and to characterize the functional groups responsible of the solid Gen/SC6OH complex stability. The infrared absorbance spectra of the complex, collected in a wide range of wavenumber and around the physiological temperature, have been analysed and compared with the spectra of the pure compounds and their physical mixture. By monitoring the most significant changes in the shape and position of the absorbance bands of the Gen functional groups, we showed that the formation and/or modification of polar bonds play the main role in the interaction of the drug with the amphiphilic CyD. From the results, Gen is shown to be entangled in SC6OH nanoaggregates, establishing hydrogen bonding with the hydrophilic PEG chains.