Virginia Campani

Mir-34: A New Weapon Against Cancer?

The microRNA(miRNA)-34a is a key regulator of tumor suppression. It controls the expression of a plethora of target proteins involved in cell cycle, differentiation and apoptosis, and antagonizes processes that are necessary for basic cancer cell viability as well as cancer stemness, metastasis, and chemoresistance. In this review, we focus on the molecular mechanisms of miR-34a-mediated tumor suppression, giving emphasis on the main miR-34a targets, as well as on the principal regulators involved in the modulation of this miRNA. Moreover, we shed light on the miR-34a role in modulating responsiveness to chemotherapy and on the phytonutrients-mediated regulation of miR-34a expression and activity in cancer cells. Given the broad anti-oncogenic activity of miR-34a, we also discuss the substantial benefits of a new therapeutic concept based on nanotechnology delivery of miRNA mimics. In fact, the replacement of oncosuppressor miRNAs provides an effective strategy against tumor heterogeneity and the selective RNA-based delivery systems seems to be an excellent platform for a safe and effective targeting of the tumor.

In vivo activity of miR-34a mimics delivered by stable nucleic acid lipid particles (SNALPs) against multiple myeloma.

Multiple myeloma (MM) is a disease with an adverse outcome and new therapeutic strategies are urgently awaited. A rising body of evidence supports the notion that microRNAs (miRNAs), master regulators of eukaryotic gene expression, may exert anti-MM activity. Here, we evaluated the activity of synthetic miR-34a in MM cells. We found that transfection of miR-34a mimics in MM cells induces a significant change of gene expression with relevant effects on multiple signal transduction pathways. We detected early inactivation of pro-survival and proliferative kinases Erk-2 and Akt followed at later time points by caspase-6 and -3 activation and apoptosis induction. To improve the in vivo delivery, we encapsulated miR-34a mimics in stable nucleic acid lipid particles (SNALPs). We found that SNALPs miR-34a were highly efficient in vitro in inhibiting growth of MM cells. Then, we investigated the activity of the SNALPs miR-34a against MM xenografts in SCID mice. We observed significant tumor growth inhibition (p<0.05) which translated in mice survival benefits (p = 0.0047). Analysis of miR-34a and NOTCH1 expression in tumor retrieved from animal demonstrated efficient delivery and gene modulation induced by SNALPs miR-34a in the absence of systemic toxicity. We here therefore provide evidence that SNALPs miR-34a may represent a promising tool for miRNA-therapeutics in MM.

Nanocarriers for topical administration of resveratrol: A comparative study

The trans-resveratrol (t-res), a non-flavonoid polyphenol extracted from different plants, has recently earned interest for application on the skin for different applications. In this work, the potential of nanocarriers, namely transfersomes and ethanol-containing vesicles, to deliver t-res into/through the skin was investigated. Thus, transfersomes with different surfactants, namely polysorbate 80 (Tw80), sodium cholate (SC) and sodium deossicholate (SDC) and ethanol-containing vesicles with different lipid composition, namely soy phosphatidylcholine (SPC) and cholesterol (chol), encapsulating t-res were prepared and characterized. The nanocarriers had a mean diameter ranging between 83 and 116 nm with a high t-res encapsulation efficiency (≥ 70%). Moreover, cytotoxicity as well as the inhibition of production of reactive oxygen species (ROS) and lipid peroxidation, following incubation of H(2)O(2)-stimulated human keratinocyte (HaCaT) with t-res, as free or encapsulated into the nanocarriers, were investigated. Only blank nanocarriers containing Tw80 or ethanol were cytotoxic and led to increase of ROS, but this effect was not observed when using nanocarriers encapsulating t-res. Finally, permeation studies on porcine skin carried out on Franz diffusion cells, showed that only ethanol-containing vesicles based SPC were able to promote t-res permeation through the skin.

Transferrin-Conjugated SNALPs Encapsulating 2′-O-Methylated miR-34a for the Treatment of Multiple Myeloma

Stable nucleic acid lipid vesicles (SNALPs) encapsulating miR-34a to treat multiple myeloma (MM) were developed. Wild type or completely 2′-O-methylated (OMet) MiR-34a was used in this study. Moreover, SNALPs were conjugated with transferrin (Tf) in order to target MM cells overexpressing transferrin receptors (TfRs). The type of miR-34a chemical backbone did not significantly affect the characteristics of SNALPs in terms of mean size, polydispersity index, and zeta potential, while the encapsulation of an OMet miR-34a resulted in a significant increase of miRNA encapsulation into the SNALPs. On the other hand, the chemical conjugation of SNALPs with Tf resulted in a significant decrease of the zeta potential, while size characteristics and miR-34a encapsulation into SNALPs were not significantly affected. In an experimental model of MM, all the animals treated with SNALPs encapsulating miR-34a showed a significant inhibition of the tumor growth. However, the use of SNALPs conjugated with Tf and encapsulating OMet miR-34a resulted in the highest increase of mice survival. These results may represent the proof of concept for the use of SNALPs encapsulating miR-34a for the treatment of MM.

Nanocarriers to Enhance the Accumulation of Vitamin K1 into the Skin.

ABSTRACTPurposeVitamin K1 (VK1) is a molecule abundant in some species of leaf vegetables with beneficial effects in humans following administration on the skin. This work investigates the possibility to use formulations based on lipid vesicles, namely liposomes, transfersomes and ethosomes, suitable to be administered on the skin by nebulization and alternative to fat semisolid preparations present on the market.MethodsLipid vesicles encapsulating VK1 were prepared and characterized. Ex-vivo experiments on Franz cells were carried out to study the VK1 accumulation/permeation in/through the skin. Vesicles interaction with the skin was investigated by confocal laser scanning microscopy (CLSM) and attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy.ResultsAll developed carriers were stable following long-term storage and were not altered following nebulization. In ex-vivo experiments, vesicles with the highest deformability index, namely transfersomes and ethosomes, led to an enhanced VK1 accumulation/permeation into/through the skin. Interestingly, the nebulization of the vesicles led to a further increase of VK1 accumulation into the skin.ConclusionsIn conclusion, to achieve a local effect of VK1 on the skin, the topical nebulization of VK1-containing transfersomes could offer a good compromise between a high VK1 penetration into the skin and a limited permeation through it.

Development of a liposome-based formulation for vitamin K1 nebulization on the skin

Vitamin K1 (VK1) is a very lipophilic and photosensitive molecule contained in some vegetables. Recently, the use of VK1 on the skin has been proposed for different pharmaceutical or cosmeceutical applications. In this study, an innovative strategy for the administration of VK1 on the skin was proposed. In particular, to overcome the drawbacks associated with a VK1-containing fatty ointment available on the market, an aqueous formulation suitable to be administered by nebulization was developed. The use of liposomes encapsulating VK1 enabled issues due to the lipophilicity of VK1 to be overcome. Thus, different liposomal formulations, with different VK1 concentrations, were prepared and characterized in terms of size, zeta potential, VK1 encapsulation into liposomes, and stability of the formulations during storage. After a first phase of screening, the selected formulation was tested by a portable device for nebulization. No alteration of the vesicle characteristics following the liposome supply through the nebulizer was found. Finally, permeation studies were carried out on pig-excised skin in Franz cells and the newly developed formulation was compared to a marketed VK1-containing ointment. In this test, an enhanced VK1 accumulation into the skin was found when using nebulized liposomes. In conclusion, in order to administer VK1 on the skin, the newly developed formulation could be a valid alternative to the products available on the market today. In particular, the use of liposomes could facilitate the multiple administrations per day by aerosol, but also increase, compared to a semi-solid preparation, the accumulation of VK1 into the epidermis and dermis.

Lipid Nanoparticles to Deliver miRNA in Cancer.

MicroRNAs (miRNAs) are a class of post-transcriptional gene expression modulators. In the past two decades, over 1500 human miRNAs were discovered. These small non-coding RNAs regulate various biological processes, including cell growth, proliferation, differentiation, and cell death. Thus, miRNAs have been proposed as new therapeutical agents in different multifactorial diseases such as cancer. Since miRNAs therapies represent a great promise, many research studies have been focused on the development of delivery strategies to overcome miRNAs biopharmaceutical issues. Lipid delivery systems are undoubtedly the non-viral carriers most largely investigated due to their biocompatibility, biodegradability, easy production, low toxicity and immunogenicity, possibility to easily modify the carriers for targeting strategies. In this mini-review we provide a rapid and updated overview on the lipid delivery system currently used to deliver miRNAs, pointing out the progresses achieved in the optimization of these nanovectors, which led up to the first clinical trial.

Lipid Nanovectors to Deliver RNA Oligonucleotides in Cancer

The growing knowledge on the mechanisms of gene silencing and gene regulation by non-coding RNAs (ncRNA), mainly small interfering RNA (siRNA) and microRNA (miRNA), is providing a significant boost to the development of new therapeutic strategies for the treatment of cancer. However, the design of RNA-based therapeutics is hampered by biopharmaceutical issues, thus requiring the use of suitable delivery strategies. In this regards, lipid nanovectors have been successfully investigated to deliver RNA in different forms of cancer. Compared to other biomaterials, lipids offer advantages such as biocompatibility, biodegradability, easy production, low cost, limited toxicity and immunogenicity. The possibility to formulate these materials in the form of nanovectors allows overcoming biopharmaceutical issues associated to the therapeutic use of RNA, with the possibility to target tumors. This review takes stock of the main lipid nanovectors proposed to deliver ncRNA. For each considered delivery strategy, the rational design and the most meaningful in vitro and in vivo results are reported and discussed.

Chitosan-Based Polyelectrolyte Complexes for Doxorubicin and Zoledronic Acid Combined Therapy to Overcome Multidrug Resistance

This study aimed to develop nanovectors co-encapsulating doxorubicin (Doxo) and zoledronic acid (Zol) for a combined therapy against Doxo-resistant tumors. Chitosan (CHI)-based polyelectrolyte complexes (PECs) prepared by ionotropic gelation technique were proposed. The influence of some experimental parameters was evaluated in order to optimize the PECs in terms of size and polydispersity index (PI). PEC stability was studied by monitoring size and zeta potential over time. In vitro studies were carried out on wild-type and Doxo-resistant cell lines, to assess both the synergism between Doxo and Zol, as well as the restoring of Doxo sensitivity. Polymer concentration, incubation time, and use of a surfactant were found to be crucial to achieving small size and monodisperse PECs. Doxo and Zol, only when encapsulated in PECs, showed a synergistic antiproliferative effect in all the tested cell lines. Importantly, the incubation of Doxo-resistant cell lines with Doxo/Zol co-encapsulating PECs resulted in the restoration of Doxo sensitivity.

Chitosan Gel to Treat Pressure Ulcers: A Clinical Pilot Study

Chitosan is biopolymer with promising properties in wound healing. Chronic wounds represent a significant burden to both the patient and the medical system. Among chronic wounds, pressure ulcers are one of the most common types of complex wound. The efficacy and the tolerability of chitosan gel formulation, prepared into the hospital pharmacy, in the treatment of pressure ulcers of moderate severity were evaluated. The endpoint of this phase II study was the reduction of the area of the lesion by at least 20% after four weeks of treatment. Thus, 20 adult volunteers with pressure ulcers within predetermined parameters were involved in a 30 days study. Dressing change was performed twice a week at outpatient clinic upon chronic wounds management. In the 90% of patients involved in the study, the treatment was effective, with a reduction of the area of the lesion and wound healing progress. The study demonstrated the efficacy of the gel formulation for treatment of pressure ulcers, also providing a strong reduction of patient management costs.