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This contribution reports the design, synthesis, photochemical properties and drug inclusion capability of two novel β-cyclodextrin (βCD) conjugates, βCD-NBFNO1 and βCD-NBFNO2, covalently integrating an N-nitroso amino-nitro-benzofurazan in the primary and secondary hydroxyl rims of the βCD scaffold, respectively through flexible spacers of different length. Both βCD conjugates are water-soluble and release nitric oxide (NO) under the input of either blue or green light, with quantum yields ΦNO (blue) = 0.13, 0.31 and ΦNO (green) = 0.007, 0.013 respectively, the former representing the largest values ever reported for nonmetal-containing NO donors activatable by visible light. The good contrast between the fluorescence green emission of the chromogenic moiety after and before the NO release permits the easy and in real-time quantification of the amount of NO generated, without the addition of external fluorescent agents. Despite the presence of the appendages, these βCD derivatives are also able to complex betaxolol, a β-blocker drug widely used for the reduction of the intraocular pressure, with binding constants Kb = 500 ± 50 and 1100 ± 100 M−1, respectively, without affecting the photochemical performances. In view of the well-known vasodilator properties of NO, the present βCD derivatives represent intriguing candidates for biopharmaceutical research studies addressed to combined therapeutic ocular applications.

Core-shell polymeric nanoparticles (NPs) made of either di-block or tri-block poly-e-caprolactone and polyethylene glycol copolymers, covalently integrating Rhodamine B in the core or the shell have been prepared and a green fluorescent NO photodonor entrapped therein. One- and two-photon fluorescence experiments demonstrate that effective Forster Resonance Energy Transfer (FRET) occurs exclusively in the di-block NPs having the Rhodamine in the core, accounting for a localization of the NO photoreleaser in the inner part of the polymeric nanocarrier. These di-block NPs are stable in the presence of human serum albumin and their cargo release NO under exclusive excitation with visible light. Two-photon imaging experiments carried out using 900 nm NIR light, demonstrate that the release of the NO photodonor can be monitored in biological tissue, herein human skin, and provide insights into the integrity and penetration depth of the NPs. Toxicity experiments performed on NCTC keratinocyte cell lines in the dark and upon visible light irradiation show good biocompatibility of the polymeric system that therefore has a great potential in light of the multifaceted therapeutic role of NO.

Polymer-based nanoparticles (NPs) with a cationic charge have emerged recently as a potent nanotool due to their unique ability to penetrate deeply inside tumor tissue and to interact preferentially with the plasma membrane of cancer cells. In this paper, we propose a general strategy to obtain biodegradable cationic NPs of poly(ϵ-caprolactone) (PCL) based on an amine terminated PCL (NH2-PCL4.2k) or its mixture with monomethoxypoly(ethylene glycol)-PCL (mPEG1k-PCL4k). Positively-charged NPs were obtained, switching to net negative values through adsorption of low molecular weight hyaluronan. NPs exposing both amine and PEG groups on the surface showed a larger fixed aqueous layer thickness as compared to fully PEGylated NPs, suggesting that PEG conformation/localization is affected by the presence of amino groups. The stability of the positively-charged NPs was affected by the presence of ions, while interaction with the human plasma protein pool indicated time-dependent protein corona formation imparting an overall negative charge. NP-induced haemolysis was low, while cytotoxicity against A549 and Calu-3 lung cancer cell lines was cell-specific as well as dose and time-dependent. Finally, the presence of amino groups greatly changed the in vivo biodistribution of the NPs in tumor-bearing mice (lung colonization of B16F10 cancer cells) allowing the amine/PEGylated NPs to accumulate mainly at the target organ. Overall, this study demonstrates that NPs with a mixed amine/PEGylated surface exhibit a peculiar biological identity that alters their interaction with the bioenvironment and are thus worthy of further investigation in the delivery of chemotherapeutics.

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.

In the last decades, nano-oncologicals bearing a polyethylene glycol (PEG) coating are being emerging as biomimetic devices able to drive their drug cargo to solid tumors through passive mechanisms. To improve selectivity toward cancer cells, nanocarriers decorated with the small ligand folate have been widely investigated. Nevertheless, a great challenge remains the effective exposition of folate on nanoparticles (NPs), which is a key prerequisite to ensure the correct binding to receptor and the following endocytic uptake. On these premises, in this study we propose a novel strategy to produce core-shell folate-targeted NPs based on diblock copolymers of poly(ε-caprolactone) (PCL) and PEG through the aid of (2-hydroxypropyl)-β-cyclodextrin (HPβCD). PCL4300-PEG2000 and PCL4300-PEG2000-Fol copolymers were synthesized, characterized and employed to produce NPs without and with HPβCD by a melting/sonication procedure. Colloidal properties of targeted NPs produced with HPβCD demonstrated a highly extended conformation of PEG chains in the shell, an enhanced interaction with a specific antibody against folate and a higher uptake in cells overexpressing folate receptor. Overall, these results suggest that proper manipulation of PEG shell conformation through HPβCD can represent a novel non-covalent strategy to modify shell features.

Background Peptide based vaccines may suffer from limited stability and inefficient delivery to professional antigen-presenting cells (APCs), such as dendritic cells (DCs). In order to overcome such limitations, several types of biodegradable nanoparticles (NPs) have been developed as carrier system for antigens. The present study describes for the first time the extensive biological characterization of cationic NPs made of poly (D,L-lactide-co-glycolide) (PLGA) and polyethylenimine (PLGA/PEI) as delivery system for protein/peptide antigens, with potential in therapeutic cancer vaccine development. Results Flow cytometry as well as confocal laser scanning microscopy (CLSM) showed that PLGA/PEI NPs are more readily taken up than PLGA NPs by both human CD14+ monocytes and mouse Hepa 1–6 hepatoma cell line. No signs of toxicity were observed in either cellular setting. Sequential image acquisition by TEM showed an intracellular apical localization for PLGA NPs and a perinuclear localization for PLGA/PEI NPs. Both NPs showed a clathrin-dependent as well as a caveolin-dependent internalization pathway and, once in the cells, they formed multivesicular endosomes (MVE). Finally, an ex vivo priming experiment showed that PLGA/PEI NPs are comparable to PLGA NPs in delivering a non-self antigen (i.e., ovalbumin - OVA) to immature dendritic cells (imDCs), which matured and induced autologous naïve CD4+ T cells to differentiate to memory (i.e., central memory and effector memory) cells. Such a differentiation was associated with a Th1 phenotype suggesting a downstream activation and amplification of a CD8+ T cell cytotoxic response. The same OVA antigen in a soluble form was unable to induce maturation of DCs, indicating that both NP formulations provided an intrinsic adjuvanting effect combined to efficient antigen delivery. Conclusions Our study represents the first report on side-by-side comparison of PLGA and PLGA/PEI NPs as strategy for protein antigen delivery. PLGA/PEI NPs are superior for cellular uptake and antigen delivery as compared to PLGA NPs. Such an evidence suggests their great potential value for vaccine development, including therapeutic cancer vaccines. Electronic supplementary material The online version of this article (doi:10.1186/s13046-015-0231-9) contains supplementary material, which is available to authorized users.

The aim of this work was to investigate the potential of small nanoparticles (NPs) made of a poly(ethylene glycol)-poly(ε-caprolactone)-amphiphilic diblock copolymer (PEG-. b-PCL, PEG. =. 2. kDa and PCL. =. 4.2. kDa) as drug carrier system through the skin. Zinc(II) phthalocyanine (ZnPc), selected as lipophilic and fluorescent model molecule, was loaded inside NPs by a melting/sonication procedure. Loaded NPs with a hydrodynamic diameter around 60. nm, a slightly negative zeta potential and a ZnPc entrapment dependent on polymer/ZnPc ratio were obtained. Spectroscopic investigations evidenced that ZnPc was entrapped in monomeric form maintaining its emission properties. The transport of ZnPc through porcine ear skin was evaluated on Franz-type diffusion cells after treatment with different vehicles (water or PEG 0.4. kDa) containing free ZnPc or ZnPc-loaded NPs without and with (2-hydroxypropyl)-β-cyclodextrin (HPβCD) as permeation enhancer. Independently of the sample tested, ZnPc was transported in the skin without reaching receptor compartment. On the other hand, ZnPc was found in the skin in large amount and also in the viable epidermis when delivered through NPs associated with HPβCD, especially in conditions limiting water evaporation. Fluorescence images of skin samples after 24. h of permeation were in line with ZnPc dosage in the skin and demonstrated the ability of NPs covalently tagged with rhodamine to penetrate the skin and to locate in the intercellular spaces. Insight into skin chemical properties upon application of NPs by confocal Raman spectroscopy demonstrated that HPβCD caused an alteration of water profile in the skin, highly reducing the degree of hydration at stratum corneum/viable epidermis interface which can promote NP transport. Taken together, these results highlight PEG-. b-PCL NPs coupled with HPβCD as a novel vehicle for the skin delivery of highly lipophilic compounds paving the way to several applications.

Background Novel polymeric nanoparticles (NPs) specifically designed for delivering chemotherapeutics in the body and aimed at improving treatment activity and selectivity, cover a very relevant area in the field of nanomedicine. Here, we describe how to build a polymer shell of Hyaluronan (HA) and Polyethyleneimine (PEI) on biodegradable NPs of poly(lactic-co-glycolic) acid (PLGA) through electrostatic interactions and to achieve NPs with unique features of sustained delivery of a docetaxel (DTX) drug cargo as well as improved intracellular uptake. Results A stable PEI or HA/PEI shell could be obtained by careful selection of layering conditions. NPs with exquisite stability in salt and protein-rich media, with size and surface charge matching biological requirements for intravenous injection and endowed with sustained DTX release could be obtained. Cytotoxicity, uptake and activity of both PLGA/PEI/HA and PLGA/PEI NPs were evaluated in CD44(+) (A549) and CD44(−) (Calu-3) lung cancer cells. In fact, PEI-coated NPs can be formed after degradation/dissociation of the surface HA because of the excess hyaluronidases overexpressed in tumour interstitium. There was no statistically significant cytotoxic effect of PLGA/PEI/HA and PLGA/PEI NPs in both cell lines, thus suggesting that introduction of PEI in NP shell was not hampered by its intrinsic toxicity. Intracellular trafficking of NPs fluorescently labeled with Rhodamine (RHO) (RHO-PLGA/PEI/HA and RHO-PLGA/PEI NPs) demonstrated an increased time-dependent uptake only for RHO-PLGA/PEI/HA NPs in A549 cells as compared to Calu-3 cells. As expected, RHO-PLGA/PEI NP uptake in A549 cells was comparable to that observed in Calu-3 cells. RHO-PLGA/PEI/HA NPs internalized into A549 cells showed a preferential perinuclear localization. Cytotoxicity data in A549 cells suggested that DTX delivered through PLGA/PEI/HA NPs exerted a more potent antiproliferative activity than free DTX. Furthermore, DTX-PLGA/PEI NPs, as hypothetical result of hyaluronidase-mediated degradation in tumor interstitium, were still able to improve the cytotoxic activity of free DTX. Conclusions Taken together, results lead us to hypothesize that biodegradable NPs coated with a PEI/HA shell represent a very promising system to treat CD44 overexpressing lung cancer. In principle, this novel nanocarrier can be extended to different single drugs and drug combinations taking advantage of the shell and core properties. Electronic supplementary material The online version of this article (doi:10.1186/s12951-015-0088-2) contains supplementary material, which is available to authorized users.

In the attempt to develop novel concepts in designing targeted nanoparticles for combination therapy of cancer, we propose here CD44-targeted hyaluronan-decorated double-coated nanoparticles (dcNPs) delivering the lipophilic chemotherapeutic docetaxel (DTX) and an anionic porphyrin (TPPS4). dcNPs are based on electrostatic interactions between a negative DTX-loaded nanoscaffold of poly(lactide-co-glycolide), a polycationic shell of polyethyleneimine entangling negatively-charged TPPS4 and finally decorated with hyaluronan (HA) to promote internalization through CD44 receptor-mediated endocytosis. DTX/TPPS4-dcNPs, prepared through layer-by-layer deposition, showed a hydrodynamic diameter of around 180 nm, negative zeta potential and efficient loading of both DTX and TPPS4. DTX/TPPS4-dcNPs were freeze-dried with trehalose giving a powder that could be easily dispersed in different media. Excellent stability of dcNPs in specific salt- and protein-containing media was found. Spectroscopic behavior of DTX/TPPS4-dcNPs demonstrated a face-to-face arrangement of the TPPS4 units in non-photoresponsive H-type aggregates accounting for an extensive aggregation of the porphyrin embedded in the shell. Experiments in MDA-MB-231 cells overexpressing the CD44 receptor demonstrated a 9.4-fold increase in the intracellular level of TPPS4 delivered from dcNPs as compared to free TPPS4. Light-induced death increased tremendously in cells that had been treated with a combination of TPPS4 and DTX delivered through dcNPs as compared with free drugs, presumably due to efficient uptake and co-localization inside the cells. In perspective, the strategy proposed here to target synergistic drug combinations through HA-decorated nanoparticles seems very attractive to improve the specificity and efficacy of cancer treatment.

With the aim to find novel therapeutical approaches for triple-negative breast cancer (TNBC) treatment, we have developed a powder for i.v. injection based on cyclodextrins and docetaxel (DTX)-loaded polyethyleneglycol-poly(epsilon-caprolactone) nanoparticles (DTX-NPs). Nanoparticles are designed to concentrate at tumor level by enhanced permeability and retention effect and release drug cargo at a sustained rate in the blood and in tumor interstitium. DTX-NPs of around 70 nm, shielding proteins and allowing a sustained DTX release for about 30 days, were produced by melting sonication technique. DTX-NPs were associated to hydroxypropyl-β-cyclodextrin to give a powder for injection with excellent dispersibility and suitable for i.v. administration. DTX-NPs were as efficient as free DTX in inhibiting cell growth of MDA-MB231 cells, even at low concentrations, and displayed a comparable in vivo antitumor efficacy and better survival in a TNBC animal model as compared with DTX commercial formulation (Taxotere®). In conclusion, PEGylated biodegradable DTX-NPs highlighted their potential in the treatment of aggressive TNBC providing a foundation for future clinical studies.

A β-cyclodextrin nanosponge cross-linked with pyromellitic dianhydride (βNS-PYRO) is reported for the first time as multifunctional ingredient in semisolid formulations for drug delivery to the skin. The role of βNS-PYRO on solubilization and stabilization of the photosensitizer benzoporphyrin-derivative monoacid ring A (BPDMA) and all-trans retinoic acid (atRA) as well as its effect on skin permeation of diclofenac (DIC) was investigated. Aqueous solutions, gels, and cream-gels were prepared from mixtures of βNS-PYRO with a conventional gelling agent at specific ratios. The incorporation of BPDMA in βNS-PYRO water solutions prevented its aggregation and gave kinetically stable complexes with high photostability and singlet oxygen generation upon irradiation. atRA incorporated in the βNS-PYRO-containing gel demonstrated a remarkable stability as compared with the formulation without βNS-PYRO, resulting in an eightfold increase of its lifetime. Skin permeation studies highlighted that βNS-PYRO in gels and cream-gels containing DIC significantly decreased the amount of drug permeated through the skin while increasing its amount in stratum corneum and viable epidermis. Overall, swellable βNS-PYRO turns to be a multifunctional coingredient with potential in topical monophasic and biphasic formulations to stabilize light-sensitive drugs and to localize the action of highly penetrating drugs in the external layers of skin.

The aim of this work is to obtain poly(ethylene glycol) (PEG) (hydrophilic)-poly(epsilon-caprolactone) (PCL) (hydrophobic) block copolymers with different architectures to point out the influence of this parameter on the water self-assembly behavior. The key role in the copolymer synthesis is played by a click chemistry strategy based on Huisgen cycloaddition, between the alkyne and azide terminal groups of different polymeric segments. The obtained copolymers are characterized by NMR, Fourier transform IR (FTIR) spectroscopy, differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD), and size-exclusion chromatography (SEC) techniques. In an aqueous environment, the hydrophilic and hydrophobic blocks of the amphiphilic copolymers form the corona and the core of the nanoaggregates, respectively, giving different morphologies as a function of the copolymer architecture. Furthermore, dynamic light scattering (DLS), transmission electron microscopy (TEM), and zeta potential measurements reveal promising features as nanocarriers of lipophilic molecules.

Due to their poor solubility and propensity to aggregate in aqueous media, therapeutic application of several photosensiting agents, such as phthalocyanines, in photodynamic therapy (PDT) of solid tumors is severely hampered. With the aim to propose a novel nanotechnological approach, in this paper biodegradable nanoassemblies based on heptakis (2-oligo(ethyleneoxide)-6-hexadecylthio-)-??-CD (SC16OH) and zinc-phthalocyanine (ZnPc) were developed and tested. Nanoassemblies, prepared by the emulsion???solvent evaporation technique, displayed a hydrodynamic diameter around 200 nm, a negative zeta potential and a satisfactory entrapment efficiency of ZnPc. Steady-state and time resolved fluorescence emission spectroscopy studies showed the entrapment of ZnPc as a monomer in the carrier, with a low tendency to self-aggregate and consequently a fairly good propensity to generate singlet oxygen after photoactivation. The interaction of ZnPc with SC16OH was elucidated by 1H-NMR, which suggested the formation of complexes between drug and both hydrophobic and hydrophilic moieties of the amphiphile. Finally, in vitro potential of the nanoassembly was evaluated in HeLa cells by following cellular uptake and photobiological activity. Overall, results suggest the suitability of the nanoassembly based on SC16OH for delivering ZnPc to cancer cells, thus inducing photodynamic anticancer effects.

Combination therapies for cancer aim to exploit either additive or synergistic effects arising from the action of two species with the final goal to maximize the therapeutic efficacy. In this work, we develop multifunctional nanoparticles (NPs) for co-delivery of the conventional anticancer drug docetaxel (DTX) and the second generation photosensitizer zinc-phthalocyanine (ZnPc) as potential dual carrier system for the combination of chemotherapy and photodynamic therapy (PDT). Biodegradable and amphiphilic block copolymers based on poly(epsilon-caprolactone) (PCL=B) and poly(ethylene oxide) (PEO=A), with AB and ABA architectures, were assembled in "core-shell" NPs and loaded with both DTX and ZnPc employing the melting/sonication method. Hydrodynamic diameters within the range 60-100 nm and low polydispersity indexes were obtained. Zeta potential was negative for all the formulations and unaffected by drug encapsulation. Concerning drug loading ability of NPs, the entrapment efficiency was related to initial ZnPc/DTX ratio. Steady-stationary and time-resolved emission fluorescence measurements pointed out the embedding of monomeric ZnPc in the NPs, excluding the presence of ZnPc self-supramolecular oligomers. The release of DTX was biphasic whereas ZnPc remained mainly associated with NPs. Singlet oxygen generation was observed when ZnPc-loaded NPs were irradiated at 610 nm within a 45 min time range, despite that ZnPc was not released in the medium. Stability of NPs in the presence of serum proteins and plasma was excellent and no toxicity toward red blood cells was found. NPs cytotoxicity was evaluated in HeLa cells irradiated for 30 min with a halogen lamp. After 72 h, viability of cells treated with ZnPc/DTX-loaded NPs strongly decreased as compared to NPs loaded only with DTX, thus showing a combined effect of both DTX and ZnPc. Superior antitumor activity of ZnPc/DTX-loaded NPs as compared to DTX-loaded NPs was confirmed in an animal model of orthotopic amelanotic melanoma, thus pointing to the application of PEO-PCL NPs in the combined chemo-photodynamic therapy of cancer. (C) 2013 Elsevier B.V. All rights reserved.