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Chiral J-aggregates of meso-tetrakis(4-sulfonatophenyl)porphyrin (TPPS[Formula: see text] have been obtained in ethanol solution triggered by addition of both enantiomeric forms of tartaric acid. A detailed spectroscopic investigation has been performed on aggregates obtained by a well-defined mixture protocol of reactants. Our findings show as both aggregation process and induced supramolecular chirality essentially depend on the concentration of the reactants. Contrary to what occurs in aqueous solution, TPPS4 in ethanol solution shows: (i) at low porphyrin concentration, an aggregation behavior characterized by a L-tartaric acid threshold whereas the D-tartaric does not work even at high concentrations, so revealing an enantiomeric discrimination; (ii) at high porphyrin concentration, a large kinetic discrimination of D- vs. L-enantiomer.

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

The development of new biocompatible delivery systems enabling controlled release of phototherapeutic agents is one of the most active areas in the field of nanomedicine. Antimicrobial photodynamic therapy (aPDT) is a promising approach to treat bacterial infections that are recalcitrant to antibiotics. Following our previous investigation on nanophototherapeutics [1], here we propose the design and characterization of a novel photosensitizing nanosystem based on the marketed cyclodextrin CAPTISOL® (sulphobutylether-beta-cyclodextrin, SBE-beta-CD) to fabricate efficient biocompatible system for aPDT. Firstly, interaction studies were carried out in order to investigate the complexation between CAPTISOL® with the tetracationic water soluble meso-tetrakis(N-methylpyridinium- 4-yl)porphine (TMPyP). Nanocomplexes based on CAPTISOL® and TMPyP (NanophotoCapitsol) were prepared in aqueous media and characterized by complementary spectroscopy and microscopic techniques such as UV/vis, fluorescence spectroscopy, AFM and scanning-near field optical luminescence (SNOL), thus investigating complex stoichiometry, stability constant, photophysical and morphological properties. Furthermore, size and z- potential were measured by Dynamic Light Scattering and Electrophoretic Light Scattering. Release and stability studies were performed in physiological conditions pointing out the role of CAPTISOL® to sustain the photosensistizer release. Finally, photoantimicrobial activity of the NanophotoCapitisol vs free porphyrin were investigated against Gram-negative Pseudomonas aeruginosa ATCC 27853, showing as the proposed nanosystems can control the time-release of porphyrin to photokill Gram-negative bacterial cells.

The importance of nanomaterials for science and technology has highly increased in the last year paving the way to the development of novel and smart formulations to overcome the limitations of organic chromophores, and significantly accelerate their clinical translation. Cyclodextrins (CDs) improve the biocompatibility of nanodelivery systems, and therefore their use, exploiting a supramolecular approach, can improve the design and applications of functional delivery systems. Aim of this work was to design a novel photosensitizing nanosystem based on CAPTISOL® (sulphobutylether-beta-cyclodextrin, SBE-beta-CD) with the tetracationic water soluble meso-tetrakis(N-methylpyridinium- 4-yl)porphine (TMpyP), as photosensitizer, for photodynamic antimicrobial therapy (PAT) able to promote internalization in cell/bacterial with biocompatible nanoformulations. PAT mechanism involves a photosensitizer (PS), bound to the colonized surface, which is promoted to its excited singlet state (1PS) by shining light on its absorption bands. This species evolves to the triplet state (3PS) that can decay by transferring energy to the surrounding oxygen and molecular components. These systems were studied with complementary techniques such as UV-Vis, steady-state and time resolved fluorescence spectroscopy and characterized to elucidate size and z-potential. The stoichiometry and the stability constant of the CAPTISOL®/TMpyP complex were calculated with the continuous variation method (Job's plot).

One of the most used strategies to achieve drug active targeting on solid tumours relies on the functionalization of carrier system with folate group as ligand for the folate receptor (FR-?). Targeted PDT treatment implies selective accommodation of a photosensitiser (PS) in tumour sites and the subsequent irradiation generates the cytotoxic singlet oxygen (1O2). Here we report nanoassemblies based on amphiphilic cyclodextrin carrier (aCD, SC6OH),1,2 entrapping pheophorbide (Pheo) as PS and tailored with folate-adamantanyl (Ada-Fol). ROESY on SC6OH/Ada-Fol points out the exposition of Fol outside the amphiphile and the strong interaction of Ada with CD cavity. SC6OH@Ada-Fol/Pheo nanoassemblies were investigated by complementary techniques such as UV-Vis, steady-state fluorescence and characterized to elucidate size, drug loading and to get insight on the PS aggregation behaviour. The nanosystem showed an hydrodynamic radius of ??300 nm, Z-potential of ??-50 mV, Pheo loading and entrapment efficiency of ??5% and ??86%, respectively. Pheo was retained for ??2 weeks in PBS (pH=7.4) at 37°C. In order to verify the targeting properties, we evaluated in vitro the effectiveness of nanoasseblies on cell growth in cell lines expressing different levels of FR-? (MCF-7 cells high expression; PC3 cells low expression). Our data indicate that the nanoassembly, upon red-light irradiation, inhibits cell proliferation depending on FR-? expression.

A new porphyrin bearing four R or S hydrogenated citronellal units directly bound to the meso positions of the porphyrin ring was synthesized and fully characterized through MALDI-TOF, NMR, UV/Vis absorption, and fluorescence emission spectroscopies. Both enantiomers exhibit a monomeric nature in a series of organic solvents. Acting on the polarity of the solvent, i.e., increasing the amount of water in mixture with acetone, aggregation occurs, as revealed by UV/Vis absorption, fluorescence emission, and resonance light scattering. The occurrence of both H- and J-type aggregates was suggested by fluorescence lifetime measurements. In contrast to the monomeric species, these aggregates exhibit CD spectra reflecting the chirality of the building blocks. AFM microscopy shows that micrometer ribbon-like structures form by the casting solution of these porphyrins in acetone/water onto a glass surface.