Rapamycin-based inhaled therapy for potential treatment of COPD-related inflammation: production and characterization of aerosolizable nano into micro (NiM) particles

Our paper describes the production and characterization of inhalable microparticles loaded with nanoparticles for the lung administration of rapamycin (Rapa). In detail, core-shell lipid/polymer hybrid nanoparticles loaded with Rapa (Rapa@Man-LPHNPs) were produced with mean size of about 128 nm and slightly negative ζ potential (-13.8 mV). A fluorescent graft polyaspartamide-poly(lactic-co-glycolic acid) copolymer (PHEA-g-RhB-g-PLGA) for use as the polymeric core was obtained by nanoprecipitation, while an appropriate mixture of DPPC and mannosylated phospholipid (DSPE-PEG2000-Man) was used to provide the macrophage-targeting lipid shell. The successful formation of Rapa@Man-LPHNPs was confirmed by TEM and DSC analyses. The loaded drug (4.3 wt% of the total weight) was slowly released from the polymeric core and protected from hydrolysis, with the amount of intact drug after 24 h of incubation in the medium being equal to 74 wt% (compared to 40% when the drug is freely incubated at the same concentration). To obtain a formulation administrable by inhalation, Rapa@Man-LPHNPs were entrapped inside PVA : LEU microparticles by using the nano into micro (NiM) strategy, specifically by spray drying (SD) in the presence of a pore-forming agent. In this way, NiM particles with geometric and theoretical aerodynamic diameters equal to 4.52 μm and 3.26 μm, respectively, were obtained. Furthermore, these particles showed optimal nebulization performance, having an FPF and an MMAD equal to 27.5% and 4.3 μm, respectively.

Cholesterol-Inulin Conjugates for Efficient SN38 Nuclear Delivery: Nanomedicines for Precision Cancer Therapy

Simple Summary

Severe limitations of conventional chemotherapy including unspecific biodistribution both at the tissue and cell organelle level have led to the necessity of developing precise and personalized therapeutic strategies. Accordingly, nanomedicine has aroused increased attention due to the versatility and precision of nano-sized drug delivery systems. One of the main advantage offered by well-designed nanoplatforms is the possibility to load, stabilize, and deliver (also at intracellular level) hydrophobic anticancer drugs, whose clinical use is strongly affected by their lower bioavailability. In this overview, the synthesis of polymeric nano-sized core-shell micelle-like nanostructures is a promising delivery strategy for hydrophobic drugs due to their excellent drug loading efficacy, stability in aqueous media, and versatile design. On these grounds, we developed stable and biodegradable inulin-based micelles for the delivery of SN38, chosen as a powerful poorly water-soluble anticancer drug. We designed an amphiphilic polysaccharide hydrophobized by partial functionalization with thiocholesterol moieties (INU-Cys-TC) via disulfide redox-sensitive bridges. We demonstrated that INU-Cys-TC can self-assemble into micelles at low concentration, encapsulating a high amount of SN38 (INU-Cys-TC@SN38) to be released in a sustained fashion. INU-Cys-TC@SN38 has proven to be capable of entering cancer and normal cells, releasing their payload, especially inside cell nuclei, where SN38 can act, providing the maximum inhibition of its molecular target. However, due to a different cell localization, INU-Cys-TC@SN38 was much more toxic for cancer cells, improving the SN38 selectivity, precision, and enhancing its anticancer effect not only toward colorectal cells, but also for breast cancer cells. This is a good example of drug repurposing due to innovative environment-sensitive delivery strategies.

Abstract

An amphiphilic inulin-thiocholesterol conjugate (INU-Cys-TC) was strategically designed as a biodegradable core-shell nanocarrier of 7-ethyl-10-hydroxy-camptothecin (SN38) to enhance its solubility and stability in aqueous media, thus exploiting its brilliant anticancer effect. INU-Cys-TC was designed to have the hydrophilic inulin backbone (external shell) partially functionalized with hydrophobic thiocholesterol moieties (internal core) through a biodegradable disulfide bond due to cysteamine bridges. Thiocholesterol moieties impair redox-sensitive self-assembling abilities, yielding to nano-sized micelles in aqueous media capable of efficiently encapsulating a high amount of SN38 (DL = 8.1%). Micelles (INU-Cys-TC@SN38) were widely characterized, demonstrating an effective and stable delivery strategy to overcome the poor water-solubility of SN38. SN38-loaded micelles showed a gradual and prolonged release of SN38 over time, and a cell- and time-dependent cytotoxicity. In particular, we show that micelles efficiently deliver SN38 inside cell nuclei, and, compared to normal cell lines, they can also enter cancer cells by endo-lysosomes, where a complete degradation can occur releasing the drug payload. Overall, the proposed micelles appear potentially effective as nanomedicines for precision cancer therapies of colorectal and breast cancer, thus improving the SN38 therapeutic index and extending its use in a huge plethora of cancers.

Inhalable Formulation Based on Lipid-Polymer Hybrid Nanoparticles for the Macrophage Targeted Delivery of Roflumilast

Here, novel lipid–polymer hybrid nanoparticles (LPHNPs), targeted to lung macrophages, were realized as potential carriers for Roflumilast administration in the management of chronic obstructive pulmonary disease (COPD). To achieve this, Roflumilast-loaded fluorescent polymeric nanoparticles, based on a polyaspartamide-polycaprolactone graft copolymer, and lipid vesicles, made from 1,2-dipalmitoyl-sn-glycero-3-phosphocholine and 1,2-distearoyl-sn-glycero-phosphoethanolamine-N-(polyethylene glycol)-mannose, were properly combined using a two-step method, successfully obtaining Roflumilast-loaded hybrid fluorescent nanoparticles (Man-LPHFNPs@Roflumilast). These exhibit colloidal size and a negative ζ potential, 50 wt % phospholipids, and a core–shell-type morphology; they slowly release the entrapped drug in a simulated physiological fluid. The surface analysis also demonstrated their high surface PEG density, which confers mucus-penetrating properties. Man-LPHFNPs@Roflumilast show high cytocompatibility toward human bronchial epithelium cells and macrophages and are uptaken by the latter through an active mannose-mediated targeting process. To achieve an inhalable formulation, the nano-into-micro strategy was applied, encapsulating Man-LPHFNPs@Roflumilast in poly(vinyl alcohol)/leucine-based microparticles by spray-drying.

Highly Homogeneous Biotinylated Carbon Nanodots: Red-Emitting Nanoheaters as Theranostic Agents toward Precision Cancer Medicine

Very recent red-emissive carbon nanodots (CDs) have shown potential as near-infrared converting tools to produce local heat useful in cancer theranostics. Besides, CDs seem very appealing for clinical applications combining hyperthermia, imaging, and drug delivery in a single platform capable of selectively targeting cancer cells. However, CDs still suffer from dramatic dot-to-dot variability issues such that a rational design of their structural, optical, and chemical characteristics for medical applications has been impossible so far. Herein, we report for the first time a simple and highly controllable layer-by-layer synthesis of biotin-decorated CDs with monodisperse size distribution, well established polymeric shell thickness, and degree of surface functionalization, endowed with strong red luminescence and the ability to convert NIR light into heat. These CDs, henceforth named CDs-PEG-BT, consist of a carbonaceous core passivated with biotin-terminated PEG₂₀₀₀ chains, which we demonstrate as active targeting groups to recognize cancer cells. The CDs-PEG-BT are designed to efficiently incorporate a high amount of anticancer drugs such as irinotecan (16-28%) and to act as NIR-activated nanoheaters capable of triggering local hyperthermia and massive drug release inside tumors, thus provoking sudden and efficient tumor death. The potential of the irinotecan-loaded CDs-PEG-BT (CDs-PEG-BT@IT) in fluorescence imaging was studied on 2D cultures and on complex 3D spheroids mimicking in vivo tumor architectures, showing their capability of selectively entering cancer cells through biotin receptors overexpressed in cell membranes. The efficient anticancer effect of these CDs was thoroughly assessed on multicellular 3D spheroids and patient organoids (tumor-on-a-dish preclinical models) to predict the drug response in humans in view of personalized medicine applications. CDs-PEG-BT@IT have a smart combination of properties, which pave the way to their real-world use as anticancer theranostic agents for image-guided photothermal applications.

Nanoreactors for the multi-functionalization of poly-histidine fragments

Water-soluble MBHA derivatives self-assemble to generate aggregates showing reactive core–shell architectures.

SPIONs embedded in polyamino acid nanogels to synergistically treat tumor microenvironment and breast cancer cells

The extremely complex tumor microenvironment (TME) in humans is the major responsible for the therapeutic failure in cancer nanomedicine. A new concept of disease-driven nanomedicine, henceforth named "Theranomics", which attempts to target cancer cells and TME on the whole, represents an attractive alternative. Herein, a nanomedicine able to co-deliver doxorubicin and a tumor suppressive proteolytic protein such as collagenase-2 was developed. We successfully obtained superparamagnetic nanogels (SPIONs/Doco@Col) via the intermolecular azide-alkyne Huisgen cycloaddition. We demonstrated that a local ECM degradation and remodeling in solid tumors by means of collagenase-2 could enhance tumor penetration of nanomedicines and the in situ sustained release of the drug payload throughout 3-D tumor spheroids up to the core (parenchyma), thus enabling a synergistic and efficient anticancer effect toward highly invasive breast tumors. We illustrate that SPIONs/Doxo@Col is also capable of reducing the invasivity of cancer cells.

Densely PEGylated Polybenzofulvene Brushes for Potential Applications in Drug Encapsulation

The technique of grafting side chains onto a linear polymeric backbone is commonly used to confer to the new polymeric material with desired properties, such as tunable solubility, ionic charge, biocompatibility, or specific interactions with biological systems. In this paper, two new polybenzofulvene backbones were assembled by spontaneous polymerization of the appropriate benzofulvene monomers (4,6-PO-BF3k and 4',6-PO-BF3k) bearing two clickable propargyloxy groups in different positions of the 3-phenylindene scaffold. Poly-4,6-PO-BF3k and poly-4',6-PO-BF3k were grafted with monomethyl oligo(ethylene glycol) (MOEG) to prepare two new polybenzofulvene brushes (i.e., poly-4,6-MOEG-9-TM-BF3k and poly-4',6-MOEG-9-TM-BF3k) by means of a "grafting onto" approach, that were characterized from the point of view of their macromolecular features, aggregation liability, and in a preliminary evaluation of biocompatibility. The obtained results make these PEGylated polybenzofulvene brushes (PPBFB) derivatives potentially useful as nanocarriers for nanoencapsulation and delivery of drug molecules.

Photothermal Ablation of Cancer Cells Using Folate-Coated Gold/ Graphene Oxide Composite

OBJECTIVE

A new tumor targeted polymer-coated gold/graphene hybrid has been developed for achieving simultaneously thermoablation and chemoterapy of folate receptor-positive cancer cells.

METHODS

The gold/graphene hybrid was prepared by depositing gold nanospheres onto graphene oxide and coating it with an inulin-folate conjugate. Paclitaxel was loaded by sonication. The hybrid was characterized by UV-Vis spectroscopy, DSC analysis and SEM microscopy. The cytotoxicity, thermoablation and anticancer activity were evaluated in vitro on MCF-7 and 16 HBE.

RESULTS

In vitro tests showed that the paclitaxel-loaded hybrid improved the effectiveness of the drug especially after photothermal treatments.

CONCLUSION

On the whole, while gold/graphene composite provided an excellent time-dependent photothermal effect, the loading of paclitaxel allowed a suitable chemotherapy, thus killing cancer cells both via a selective laser beam thermoablation and hyperthermia-triggered chemotherapy.

Near-Infrared Light Responsive Folate Targeted Gold Nanorods for Combined Photothermal-Chemotherapy of Osteosarcoma

Folate-targeted gold nanorods (GNRs) are proposed as selective theranostic agents for osteosarcoma treatment. An amphiphilic polysaccharide based graft-copolymer (INU-LA-PEG-FA) and an amino derivative of the α,β-poly(N-2-hydroxyethyl)-d,l-aspartamide functionalized with folic acid (PHEA-EDA-FA), have been synthesized to act as coating agents for GNRs. The obtained polymer-coated GNRs were characterized in terms of size, shape, zeta potential, chemical composition, and aqueous stability. They protected the anticancer drug nutlin-3 and were able to deliver it efficiently in different physiological media. The ability of the proposed systems to selectively kill tumor cells was tested on U2OS cancer cells expressing high levels of FRs and compared with human bronchial epithelial cells (16HBE) and human dermal fibroblasts (HDFa). The property of the nanosystems of efficiently controlling drug release upon NIR laser irradiation and of acting as an excellent hyperthermia agent as well as Two Photon Luminescence imaging contrast agents was demonstrated. The proposed folate-targeted GNRs have also been tested in terms of chemoterapeutic and thermoablation efficacy on tridimensional (3-D) osteosarcoma models.

Enhanced adhesion and in situ photothermal ablation of cancer cells in surface-functionalized electrospun microfiber scaffold with graphene oxide

The physicochemical characteristics of a biomaterial surface highly affect the interaction with living cells. Recently, much attention has been focused on the adhesion properties of functional biomaterials toward cancer cells, since is expected to control metastatic spread of a tumor, which is related to good probability containing the progression of disease burden. Here, we designed an implantable poly(caprolactone)-based electrospun microfiber scaffold, henceforth PCL_MF-GO, to simultaneously capture and kill cancer cells by tuning physicochemical features of the hybrid surface through nitrogen plasma activation and hetero-phase graphene oxide (GO) covalent functionalization. The surface immobilization of GO implies enhanced cell adhesion and proliferation, promoting the selective adhesion of cancer cells, even if allowing cancer associated fibroblast (CAFs) capture. We also display that the functionalization with GO, thanks to the high near-infrared (NIR) absorbance, enables the discrete photothermal eradication of the captured cancer cells in situ (≈98%).

Double-Network-Structured Graphene Oxide-Containing Nanogels as Photothermal Agents for the Treatment of Colorectal Cancer

Here, we reported the production of hyaluronic acid/polyaspartamide-based double-network nanogels for the potential treatment of colorectal carcinoma. Graphene oxide, thanks to the huge aromatic surface area, allows to easily load high amount of irinotecan (33.0% w/w) and confers to the system hyperthermic properties when irradiated with a near-infrared (NIR) laser beam. We demonstrate that the release of antitumor drug is influenced both by the pH of the external medium and the NIR irradiation process. In vitro biological studies, conducted on human colon cancer cells (HCT 116), revealed that nanogels are uptaken by the cancer cells and, in the presence of the antitumor drug, can produce a synergistic hyperthermic/cytotoxic effect. Finally, 3D experiments demonstrate that it is possible to conduct thermal ablation of solid tumors after the intratumoral administration of nanogels.

Smart Inulin-Based Polycationic Nanodevices for siRNA Delivery

The advances of short interfering RNA (siRNA) mediated therapy provide a powerful option for the treatment of many diseases by silencing the expression of targeted genes including cancer development and progression. Inulin is a very simple and biocompatible polysaccharide proposed by our groups to produce interesting delivery systems for Nucleic Acid Based Drugs (NABDs), such as siRNA, either as polycations able to give polyplexes and polymeric coatings for nanosystems having a metallic core. In this research field, different functionalizing groups were linked to the inulin backbone with specific aims including oligoamine such as Ethylendiammine (EDA), Diethylediamine (DETA), Spermine, (SPM) etc. In this contribution the main Inulin-based nanodevices for the delivery of siRNA have been reported, analysed and compared with particular reference to their chemical design and structure, biocompatibility, siRNA complexing ability, silencing ability.

Polyaminoacid–doxorubicin prodrug micelles as highly selective therapeutics for targeted cancer therapy

An amphiphilic copolymer carrying high-dose doxorubicin (21% on a weight basis), PHEA–EDA–P,C–Doxo, was prepared by coupling doxorubicin with a biocompatible polyaminoacid through a pH-sensitive spacer.

Hyaluronan-coated polybenzofulvene brushes as biomimetic materials

A polybenzofulvene brush was enveloped by means of nona(ethylene glycol) arms into hyaluronan shells.

Development of a simple, biocompatible and cost-effective Inulin-Diethylenetriamine based siRNA delivery system

Small interfering RNAs (siRNAs) have the potential to be of therapeutic value for many human diseases. So far, however, a serious obstacle to their therapeutic use is represented by the absence of appropriate delivery systems able to protect them from degradation and to allow an efficient cellular uptake. In this work we developed a siRNA delivery system based on inulin (Inu), an abundant and natural polysaccharide. Inu was functionalized via the conjugation with diethylenetriamine (DETA) residues to form the complex Inu-DETA. We studied the size, surface charge and the shape of the Inu-DETA/siRNA complexes; additionally, the cytotoxicity, the silencing efficacy and the cell uptake-mechanisms were studied in the human bronchial epithelial cells (16HBE) and in the hepatocellular carcinoma derived cells (JHH6). The results presented here indicate that Inu-DETA copolymers can effectively bind siRNAs, are highly cytocompatible and, in JHH6, can effectively deliver functional siRNAs. Optimal delivery is observed using a weight ratio Inu-DETA/siRNA of 4 that corresponds to polyplexes with an average size of 600nm and a slightly negative surface charge. Moreover, the uptake and trafficking mechanisms, mainly based on micropinocytosis and clatrin mediated endocytosis, allow the homogeneous diffusion of siRNA within the cytoplasm of JHH6. Notably, in 16 HBE where the trafficking mechanism (caveolae mediated endocytosis) does not allow an even distribution of siRNA within the cell cytoplasm, no significant siRNA activity is observed. In conclusion, we developed a novel inulin-based siRNA delivery system able to efficiently release siRNA in JHH6 with negligible cytotoxicity thus opening the way for further testing in more complex in vivo models.

Self-organized environment-sensitive inulin–doxorubicin conjugate with a selective cytotoxic effect towards cancer cells

An inulin-based copolymer bearing high dose doxorubicin (18.45 % w/w), INU-EDA-P,C-DOXO, was prepared by coupling doxorubicin with inulin though citraconylamide bridge used as pH sensitive spacer. Its smart and selective anticancer effect was proved.

Polybenzofulvene derivatives bearing dynamic binding sites as potential anticancer drug delivery systems

A polybenzofulvene brush is functionalized with a synthetic receptor capable of interacting with doxorubicin.

Polyaspartamide-doxorubicin conjugate as potential prodrug for anticancer therapy

PURPOSE

To synthesize a new polymeric prodrug based on α,β-poly(N-2-hydroxyethyl)(2-aminoethylcarbamate)-d,l-aspartamide copolymer bearing amine groups in the side chain (PHEA-EDA), covalently linked to the anticancer drug doxorubicin and to test its potential application in anticancer therapy.

METHODS

The drug was previously derivatized with a biocompatible and hydrophilic linker, leading to a doxorubicin derivative highly reactive with amino groups of PHEA-EDA. The PHEA-EDA-DOXO prodrug was characterized in terms of chemical stability. The pharmacokinetics, biodistribution and cytotoxicity of the product was investigated in vitro and in vivo on human breast cancer MCF-7 and T47D cell lines and NOD-SCID mice bearing a MCF-7 human breast carcinoma xenograft. Data collected were compared to those obtained using free doxorubicin.

RESULTS

The final polymeric product is water soluble and easily hydrolysable in vivo, due to the presence of ester and amide bonds along the spacer between the drug and the polymeric backbone. In vitro tests showed a retarded cytotoxic effect on tumor cells, whereas a significant improvement of the in vivo antitumor activity of PHEA-EDA-DOXO and a survival advantage of the treated NOD-SCID mice was evidenced, compared to that of free doxorubicin.

CONCLUSIONS

The features of the PHEA-EDA-DOXO provide a potential protection of the drug from the plasmatic enzymatic degradation and clearance, an improvement of the blood pharmacokinetic parameters and a suitable body biodistribution. The data collected support the promising rationale of the proposed macromolecular prodrug PHEA-EDA-DOXO for further potential development and application in the treatment of solid cancer diseases.

Amphiphilic inulin graft co-polymers as self-assembling micelles for doxorubicin delivery

This paper reports the synthesis and characterization of a new amphiphilic inulin graft copolymer able to self-assemble in water into a micelle type structure and to deliver the anticancer model drug doxorubicin. For this aim, inulin was chemically modified in the side chain with primary amine groups (INU-EDA) and these were used as reactive moieties for the conjugation of poly ethylene glycol 2000 and succinyl-ceramide. The CMC of obtained amphiphilic inulin derivatives (INU-ceramide and INU-ceramide-PEG₂₀₀₀) was measured by means of fluorescence analysis using pyrene as the fluorescent probe. The obtained micelles were characterized by DLS and AFM analysis and the ability to release the loaded doxorubicin was studied in different media. Finally the cytotoxicity profile on both cancer (HCT116) and normal (16 HBE) cell lines and in vitro ability to deliver the drug into cancer cells were evaluated.

Polymeric nanocarriers for magnetic targeted drug delivery: preparation, characterization, and in vitro and in vivo evaluation

In this paper the preparation of magnetic nanocarriers (MNCs), containing superparamagnetic domains, is reported, useful as potential magnetically targeted drug delivery systems. The preparation of MNCs was performed by using the PHEA-IB-p(BMA) graft copolymer as coating material through the homogenization-solvent evaporation method. Magnetic and nonmagnetic nanocarriers containing flutamide (FLU-MNCs) were prepared. The prepared nanocarriers have been exhaustively characterized by dynamic light scattering (DLS), transmission electron microscopy (TEM), and magnetic measurements. Biological evaluation was performed by in vitro cytotoxicity and cell uptake tests and in vivo biodistribution studies. Magnetic nanocarriers showed dimensions of about 300 nm with a narrow size distribution, an amount of loaded FLU of 20% (w/w), and a superparamagnetic behavior. Cell culture experiments performed on prostate cancer cell line LNCaP demonstrated the cytotoxic effect of FLU-MNCs. In vivo biodistribution studies carried out by the application of an external magnetic field in rats demonstrated the effect of the external magnet on modifying the biodistribution of FLU-MNCs. FLU-MNCs resulted efficiently internalized by tumor cells and susceptible to magnetic targeting by application of an external magnetic field. The proposed nanocarriers can represent a very promising approach to obtain an efficient magnetically targeted anticancer drug delivery system.

Montmorillonite nanodevices for the colon metronidazole delivery

The adsorption profiles of the antibiotic metronidazole (MNE) into the K10-montmorillonite (MMT-K10) clay and the subsequent release have been investigated as a function of pH and MNE/MMT-K10 ratio, in order to evaluate the potential of the MNE/MMT-K10 hybrids as controlled drug delivery system. The adsorption mechanism has been first elucidated by performing complementary equilibrium and kinetic studies and through the X-ray diffractometry (XRD) characterization of the obtained composite materials. The gathered results allowed us to propose a mechanism consisting of a multi-step pathway involving the neutral and the cationic form of the drug, which interact with different sites of the clay surfaces, i.e. the interlayer region and the faces of the lamella. In a second step the drug release kinetics has been studied under physiological pH mimicking conditions simulating the oral drug administration and delivery. For the sake of comparison the commercial formulation has also been employed for the release studies. The investigation of the release profiles and the comparison with the commercial formulation of the drug reveal that the new-tailor made formulation could be fruitful exploited for successfully prolonged the action of drug in the desired site.

Cell uptake enhancement of folate targeted polymer coated magnetic nanoparticles

Dual targeted drug delivery systems represent a potential platform for developing efficient vector to tumor sites. In this study we evaluated a folate- and magnetic-targeted nanocarriers based on 10 nm iron oxide nanodomais coated with the properly synthesized and characterized folic acid (FA)-functionalized amphiphilic copolymer PHEA-PLA-PEG-FA. FA was chemically conjugated to one end of diamino-polyethylene glycol of 2000 Da, in order to ensure its exposition on the polymer coated magnetic nanoparticles (MNPs-FA). The prepared nanoparticles have been exhaustively characterized by different methods, including DLS, SEM, FT-IR and magnetic measurements. Magnetic nanoparticles showed dimension of about 37 nm with a narrow size distribution and a characteristic superparamagnetic behaviour. The lack of cytotoxicity of MNPs-FA and MNPs was assessed both on MCF7 cells, used as a model tumor cell line, and on 16HBE, used as normal human cell model, by evaluating cell viability using MTS assay, while the preferential internalization of MNPs-FA into tumor cells rather that into normal cells was confirmed by the quantization of internalized iron oxide. Uptake studies were also performed in the presence of a permanent magnet in order to verify the synergistic effect of magnetic field in enhancing the internalization of magnetic nanoparticles. Finally, real-time confocal microscopy experiments were carried out to further confirmed that FA ligand enhances the MNPs-FA accumulation into cancer cell cytoplasm.