Biodegradable core-shell nanoassemblies for the delivery of docetaxel and Zn(II)-phthalocyanine inspired by combination therapy for cancer.

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(ε-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 60-100nm 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 610nm within a 45min 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 30min with a halogen lamp. After 72h, 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.

Conte C ，Ungaro F ，Maglio G ，Tirino P ，Siracusano G ，Sciortino MT ，Leone N ，Palma G ，Barbieri A ，Arra C ，Mazzaglia A ，Quaglia F ... -  《-》

Nanoassemblies based on non-ionic amphiphilic cyclodextrin hosting Zn(II)-phthalocyanine and docetaxel: Design, physicochemical properties and intracellular effects.

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-)-β-CD (SC16OH) 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 ≅ 200nm, a negative zeta potential (≅ -27mV) 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 SC16OH with DTX, co-entrapped with ZnPc, was elucidated by (1)H NMR and 2D ROESY, which suggested the presence of the chemotherapeutic in the hydrophobic portion of SC16OH. 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.

Conte C ，Scala A ，Siracusano G ，Sortino G ，Pennisi R ，Piperno A ，Miro A ，Ungaro F ，Sciortino MT ，Quaglia F ，Mazzaglia A ... -  《-》

In vitro anticancer activity of docetaxel-loaded micelles based on poly(ethylene oxide)-poly(epsilon-caprolactone) block copolymers: Do nanocarrier properties have a role?

In this paper we have investigated the behavior of core-shell poly(ethylene oxide)-poly(epsilon-caprolactone) (PEO-PCL) micelles derived from copolymers with linear triblock (TR) and 4-arm star-diblock (ST) architectures for the delivery of docetaxel (DTX). DTX was loaded inside micelles (DTX-TR(m) and DTX-ST(m)) with high efficiency and released slowly for more than two weeks. DTX-loaded micelles based on both copolymers had very similar properties in terms of mean size, zeta potential, loading ability and release rate in buffered saline. However, the stability of DTX-ST(m) was very poor in aqueous media with proteins resulting in a strong and progressive aggregation. We studied the effect of increasing concentrations of free DTX or DTX-loaded micelles on growth inhibition of human breast MCF-7 and MDA-MB468 and prostate PC3 and DU145 adenocarcinoma cell lines. DTX-loaded TR micelles induced cell growth inhibition similarly to free DTX whereas DTX-ST(m) showed lower cytotoxicity. On the other hand, by normalizing IC(50) values for the actual amount of DTX released from micelles in the medium, DTX-loaded ST micelles became more active than free DTX in all cell lines tested. Both free DTX and DTX-loaded TR micelles displayed a significantly lower cytotoxic activity in G(2)/M phase synchronized cells, whereas cytotoxicity of DTX-loaded ST micelles did not change. Cytotoxicity was related to micelle stability, uptake and release rate in cell culture media. Our results suggest that for a correct interpretation of cytotoxicity of nanocarriers, the evaluation of their behavior in biologically relevant conditions is of utmost importance to select proper systems for further in vivo testing.

Ostacolo L ，Marra M ，Ungaro F ，Zappavigna S ，Maglio G ，Quaglia F ，Abbruzzese A ，Caraglia M ... -  《-》

Zinc(II) phthalocyanine loaded PLGA nanoparticles for photodynamic therapy use.

Ricci-Júnior E ，Marchetti JM 《-》

Antitumor activity of PEGylated biodegradable nanoparticles for sustained release of docetaxel in triple-negative breast cancer.

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.

Palma G ，Conte C ，Barbieri A ，Bimonte S ，Luciano A ，Rea D ，Ungaro F ，Tirino P ，Quaglia F ，Arra C ... -  《-》