Clizia Guccione

Essential Oils Loaded in Nanosystems: A Developing Strategy for a Successful Therapeutic Approach

Essential oils are complex blends of a variety of volatile molecules such as terpenoids, phenol-derived aromatic components, and aliphatic components having a strong interest in pharmaceutical, sanitary, cosmetic, agricultural, and food industries. Since the middle ages, essential oils have been widely used for bactericidal, virucidal, fungicidal, antiparasitical, insecticidal, and other medicinal properties such as analgesic, sedative, anti-inflammatory, spasmolytic, and locally anaesthetic remedies. In this review their nanoencapsulation in drug delivery systems has been proposed for their capability of decreasing volatility, improving the stability, water solubility, and efficacy of essential oil-based formulations, by maintenance of therapeutic efficacy. Two categories of nanocarriers can be proposed: polymeric nanoparticulate formulations, extensively studied with significant improvement of the essential oil antimicrobial activity, and lipid carriers, including liposomes, solid lipid nanoparticles, nanostructured lipid particles, and nano- and microemulsions. Furthermore, molecular complexes such as cyclodextrin inclusion complexes also represent a valid strategy to increase water solubility and stability and bioavailability and decrease volatility of essential oils.

Improving on Nature: The Role of Nanomedicine in the Development of Clinical Natural Drugs

Natural products have been used as a major source of drugs for millennia, and about half of the pharmaceuticals in use today are derived from natural products. However, their efficacy can be limited because of their low hydrophilicity and intrinsic dissolution rate(s), or physical/chemical instability. In addition, they can present scarce absorption, poor pharmacokinetics and bioavailability, scarce biodistribution, first-pass metabolism, trivial penetration and accumulation in the organs of the body, or low targeting efficacy. Novel nanoformulations based on drug delivery systems, namely nanoparticles, micelles, and vesicles, offer significant promise in overcoming these limitations. Nowadays, nanomedicine is crucial in developing appropriate therapeutic treatments of essential drugs, specifically antitumor and antiparasistic agents (i.e., Taxol, vincristine, camptothecin, doxorubicin, artemisinin) and other emerging molecules with pleiotropic functions (i.e., resveratrol, curcumin, salvianolic acid B, honokiol). Additionally, the number of nanoformulations developed with flavonoids, in particular rutin, quercetin, silymarin, and green tea catechins, is constantly increasing, and a significant number of publications have appeared in the last decade pertaining to nanoformulations based on extracts and essential oils. Most of these studies report very promising nanoformulations with sustained release and improved bioavailability at much lower doses than conventional preparations, and in many cases, also a better safety profile.

Combined HPLC-DAD–MS, HPLC–MSn and NMR spectroscopy for quality control of plant extracts: The case of a commercial blend sold as dietary supplement

The efficiency of 1D and 2D NMR spectroscopy along with HPLC-DAD-MS analyses in characterising the content of a dietary supplement is demonstrated. Experiments directly performed on a lyophilised sample of a commercial product gave details on the quality control of the product. The lack of the marker constituents of some of the declared plant species (Crataegus oxyacantha, Olea europea, Capsella bursa-pastoris and Fumaria officinalis) and the presence of banned adulterants, responsible for the strong antihypertensive effect of the supplement were established. The analyses proved the presence of indole alkaloids belonging to the group of Rauwolfia sp., such as ajmaline, reserpine and yohimbine. Quantitative HPLC analysis showed that the content of reserpine in the product was in the therapeutic range and therefore responsible for the collapses of the patients.

Albumin Nanoparticles for Brain Delivery: A Comparison of Chemical versus Thermal Methods and in vivo Behavior.

Human serum albumin nanoparticles (NPs) have gained considerable attention owing to their high loading capacity for various drugs and the fact that they are well tolerated. The aim of this work was to investigate two different methods to produce NPs without the use of organic solvents and to obtain useful drug‐delivery systems to cross the blood–brain barrier. NPs were obtained by coacervation, using both chemical and thermal cross‐linking processes. They were developed and optimized to target brain tissues after parenteral administration in healthy rats. Furthermore, their distribution, cellular uptake, and fate were investigated in vivo after intracerebral injection in healthy rats. The toxicity of the developed carriers was estimated by behavioral tests. All NPs were chemically and physically characterized by dynamic light scattering, transmission electron microscopy, and high‐performance liquid chromatography coupled with diode array and fluorimetric detectors. Their distribution and fate in the brain were evaluated by fluorescence microscopy. NPs were observed to be located in different brain tissues depending on the mode of injection, and did not induce an inflammatory response. Behavioral tests demonstrated no locomotor, explorative, or cognitive function impairment induced by the NPs.

Development of Blood-Brain Barrier Permeable Nanoparticles as Potential Carriers for Salvianolic Acid B to CNS

The blood-brain barrier hinders the passage of systemically delivered therapeutics and the brain extracellular matrix limits the distribution and durability of locally delivered agents. Drug-loaded nanocarriers represent a promising strategy to overcome these barriers and address specific drug delivery challenges due to their small size and versatile design. We synthetized [fluorescent poly(ethyl-cyanoacrylate) nanoparticles coated with Tween 80 by an emulsion polymerization method to target and reach the brain after intravenous and intraperitoneal administration. Nanoparticles were characterized in terms of dimensional analysis, polydispersity and zeta potential (ζ-potential), morphology, encapsulation efficacy, and loading capacity. After intracerebral injection in healthy rats, nanoparticles were distributed within the injected hemisphere and mainly interacted with microglial cells, presumably involved in their clearance by phagocytosis. Furthermore, nanoparticles were able to pass the blood-brain barrier after systemic administration in rats, and the lack of toxicity in C57/B6 mice chronically administered was highlighted. The data obtained helped to clarify the nanoparticles distribution, accumulation, fate, and toxicity into the brain. The selected nanoparticles may represent a biocompatible promising carrier to be further investigated as brain delivery systems. Salvianolic acid B from Salvia miltiorrhiza is a promising molecule in the protection of degeneration in several animal models by various biological mechanisms, but its poor chemical stability and low bioavailability limits its clinical application for central nervous system neuronal injury and degeneration. Nanoparticles were loaded with salvianolic acid B obtaining an encapsulation efficacy and loading capacities of 98.70 % ± 0.45 and 53.3 % ± 0.24, respectively. They were suitable for parental administration because their mean diameter was smaller than 300 nm, with a polydispersity of 0.04 ± 0.03, and a ζ-potential of - 8.38 mV ± 3.87. The in vitro release of salvianolic acid B from the nanoparticles was sustained and prolonged during 8 h, suitable for a promising clinical application.

Enhanced intra-cutaneous delivery of a Mn-containing antioxidant drug by high-frequency ultrasounds

This study was carried out to evaluate whether high-frequency ultrasounds, a commonly used aesthetic medicine treatment for skin rejuvenation, may enhance the penetration of the Mn-containing compound Mn(II)(Me2DO2A) (manganese(II) 4,10-dimethyl-1,4,7,10-tetraazacyclododecane-1,7-diacetate) biologically active as a superoxide anion scavenger, in the cutaneous layers of ex vivo human skin explants. Although its antioxidant properties are well known and the compound is basically not toxic in animal models, its trans-cutaneous permeation and its toxicological profile at a systemic level have not yet fully analyzed. Therefore, its possible penetration in the deep cutaneous layers was also evaluated. To this purpose, Mn(II)(Me2DO2A) was formulated as emulsion-gel, lipogel and hydrogel. These different formulations were also tested in combination with high-frequency ultrasounds (10-3500 Hz frequency modulation on a 5 MHz main frequency) used as physical permeation enhancers, delivered by a MedVisage™ device (General Project, Montespertoli, Italy) currently used for aesthetic medicine purposes. The permeation of the Mn-containing compound from the formulations was evaluated by inductively coupled plasma atomic emission spectrometry (ICP-AES) measurements of Mn in horizontal cryosections of the skin samples cut at different depths to separate the epidermis, papillary and reticular dermis, as well as by vertical Franz diffusion cells. The results show that the hydrogel formulation yielded the highest transepidermal delivery of Mn(II)(Me2DO2A) and that the application of ultrasounds (3 W, FM 100 Hz, 2×10 s) significantly enhanced its penetration into the epidermis and upper dermal layers. Of note, nearly undetectable amounts of Mn(II)(Me2DO2A) were detected in the reticular dermis and the Franz cell fluid. Although an in vivo confirmation of these results will be necessary, this method may allow to minimize undesired drug passage to the bloodstream and undesired delivery to non-target internal organs and avoiding its renal excretion and release into the environment.

Andrographolide-loaded nanoparticles for brain delivery: Formulation, characterisation and in vitro permeability using hCMEC/D3 cell line

Graphical abstract Figure. No Caption available. HighlightsAndrographolide was loaded into albumin and poly‐ethylcyanoacrylate nanoparticles.Size, zeta‐potential, polydispersity and morphology were investigated.Blood brain barrier permeability was assessed using in vitro cell based model.UPLC‐MS/MS method was developed and validated according to EMA/FDA guidelines.Albumin nanoparticles improved permeation maintaining the integrity of cell layer. Abstract Andrographolide (AG) is a major diterpenoid of the Asian medicinal plant Andrographis paniculata which has shown exciting pharmacological potential for the treatment of inflammation‐related pathologies including neurodegenerative disorders. Conversely, the low bioavailability of AG still represents a limiting factor for its use. To overcome these limitations, AG was loaded into human serum albumin based nanoparticles (HSA NPs) and poly ethylcyanoacrylate nanoparticles (PECA NPs). HSA NPs were prepared by thermal (HSAT AG NPs) and chemical cross‐linking (HSAC AG NPs), while PECA AG NPs were produced by emulsion‐polymerization. NPs were characterized in terms of size, zeta (&zgr;)‐potential, polydispersity, and release studies of AG. In addition, the ability of free AG and AG‐loaded in PECA and HSAT NPs to cross the blood‐brain barrier (BBB) was assessed using an in vitro BBB model based on human cerebral microvascular endothelial cell line (hCMEC/D3). For BBB drug permeability assays, a quantitative UPLC‐MS/MS method for AG in Ringer HEPES buffer was developed and validated according to international regulatory guidelines for industry. Free AG did not permeate the BBB model, as also predicted by in silico studies. HSAT NPs improved by two‐fold the permeation of AG while maintaining the integrity of the cell layer, while PECA NPs temporarily disrupted BBB integrity.

Lipid Nanocarriers for Oral Delivery of Serenoa repens CO2 Extract: A Study of Microemulsion and Self-Microemulsifying Drug Delivery Systems

The aim of this study was the development and characterization of lipid nanocarriers using food grade components for oral delivery of Serenoa repens CO2 extract, namely microemulsions (MEs) and self-microemulsifying drug delivery systems (SMEDDSs) to improve the oral absorption. A commercial blend (CB) containing 320 of S. repens CO2 extract plus the aqueous soluble extracts of nettle root and pineapple stem was formulated in two MEs and two SMEDDSs. The optimized ME loaded with the CB (CBM2) had a very low content of water (only 17.3%). The drug delivery systems were characterized by dynamic light scattering, transmission electron microscopy, and high-performance liquid chromatography (HPLC) with a diode-array detector analyses in order to evaluate the size, the homogeneity, the morphology, and the encapsulation efficiency. β-carotene was selected as marker for the quantitative HPLC analysis. Additionally, physical and chemical stabilities were acceptable during 3 wk at 4 °C. Stability of these nanocarriers in simulated stomach and intestinal conditions was proved. Finally, the improvement of oral absorption of S. repens was studied in vitro using parallel artificial membrane permeability assay. An enhancement of oral permeation was found in both CBM2 and CBS2 nanoformulations comparing with the CB and S. repens CO2 extract. The best performance was obtained by the CBM2 nanoformulation (~ 17%) predicting a 30 - 70% passive oral human absorption in vivo.