Anna Maria Panico

In vitro retinoic acid release and skin permeation from different liposome formulations

The effect of including charged phospholipids (both negative and positive) and/or cholesterol in liposomal formulations on retinoic acid (RA) in vitro release and permeation through human stratum corneum and epidermis was studied. No significant difference in RA release was observed comparing the different liposomal formulations tested. On the contrary, positively charged liposomes provided significantly higher RA skin permeation compared to negatively charged vesicles which, in turn, showed RA permeation through the skin similar to that obtained from neutral liposomes. Furthermore, the inclusion of cholesterol in charged liposomes did not significantly affect RA skin permeation.

Characterization and in-vivo ocular absorption of liposome-encapsulated acyclovir.

The potential of liposomes as an in‐vivo ophthalmic drug delivery system for acyclovir was investigated.

Aminothiazole derivatives with antidegenerative activity on cartilage

A series of 2-dialkylamino-N-(4-substituted thiazolyl-2)acetamides and 3-dialkylamino-N-(4-substituted thiazolyl-2)propionamides were synthesized and evaluated for their anti-inflammatory activity. Encouraging results led us to investigate the effect of these compounds on NO production and GAGs release. Their effects were evaluated in vitro on the metabolism of pig cartilage, treated with IL-1beta. The amount of glycosaminoglycans (GAGs) and the production of nitric oxide (NO) in the culture medium were determined. The results, obtained, showed that all compounds, in the presence of IL-1beta, blocked the cartilage breakdown, with different behavior. A quantitative structure-activity relationship (QSAR) study was performed.

Quantitative determination of hydrophobic compound entrapment in dipalmitoylphosphatidylcholine liposomes by differential scanning calorimetry

In this paper the feasibility of determing the percentage of drug entrapment (PDE) in dipalmitoylphosphatidylcholine (DPPC) liposomes by using differential scanning calorimetry (DSC) was assessed. Three different lipophilic compounds, namely testosterone, vitamin E acetate and retinoic acid, were encapsulated in multilamellar liposomes and their PDE values were determined by DSC and by conventional separative techniques, such as dialysis and centrifugation. PDE values of testosterone, vitamin E acetate and retinoic acid determined by DSC analysis, applying Vant Hoff equation, were 6.3 ± 0.1, 68.9 ± 0.7 and 87.8 ± 0.6, respectively. Dialysis was performed at different time intervals, 3, 6, 9 and 12 h, on DPPC liposomes entrapping the compounds tested. The duration of the dialysis process strongly affected the quantification of testosterone incorporated in DPPC liposomes while it slightly influenced the determination of vitamin E acetate and retinoic acid PDE values. Centrifugation of DPPC liposomes entrapping the compounds tested was carried out at different rpm (6000, 9000 and 12000 rpm). No significant difference was observed comparing PDE values obtained centrifugating at different rpm. Comparing PDE values obtained by dialysis (at 9 and 12 h) and centrifugation for each compound with the corresponding PDE values determined by DSC, linear relationships were observed. These results suggest that DSC analysis could be regarded as a suitable technique for the quantitative determination of the percentage of hydrophobic compound entrapped in DPPC liposomes.

Heteroarylimino-4-thiazolidinones as inhibitors of cartilage degradation.

2-Benzo[d]thiazolyl- and 2-benzo[d]isothiazolyl-imino-5-benzylidene-4-thiazolidinone derivatives were investigated as potential metalloproteinases (MMPs) inhibitors and evaluated for their antidegenerative activity on human chondrocyte cultures stimulated by IL-1β, using an experimental model that reproduces the mechanisms involved in osteoarthritic (OA) diseases. Cell viability, the amount of glycosaminoglycans (GAGs) and the production of nitric oxide (NO) were measured. The most potent compound, 5-(4-methoxy-benzylidene)-2-(benzo[d]isothiazol-3-ylimino)-thiazolidin-4-one (4b), a MMP-13 inhibitor at nanomolar concentration (IC(50)=0.036 μM), could be considered as a lead compound for the development of novel clinical agents, inhibitors of cartilage degradation, for the treatment of OA.

Benzisothiazolyliminothiazolidin-4-ones with Chondroprotective Properties: Searching for Potent and Selective Inhibitors of MMP-13

Matrix metalloproteinase-13 (MMP-13) plays a key role in the degradation of type II collagen in cartilage and bone in osteoarthritis. Nonselective inhibition of different MMPs by the early inhibitors appears to be the reason for their toxicity and limited efficacy. Recent findings suggest that selective inhibition of MMP-13 could avoid toxicity and that non-zinc-chelating MMP inhibitors appear to be the most promising agents toward achieving selectivity, since the allosteric binding sites are not shared by different MMPs. Biochemical, histological and clinical models support this findings. [1b,3] Therefore, effective MMP-13 inhibition would be a novel, disease-modifying therapy for the treatment of osteoarthritis. Our recent efforts in the search for new agents with antidegenerative activity, as evaluated in human chondrocyte cultures stimulated by IL-1b, have resulted in the discovery of a series of heteroarylimino-4-thiazolidinones that significantly inhibit MMPs and other inflammatory mediators. Among these, a potent and selective MMP-13 inhibitor has been identified (MMP-13, IC50 = 0.036 mm ; MMP-3, IC50 >100 mm) based upon a 2-(benzo[d]isothiazol-3-ylimino)-5-(4-methoxybenzylidene)thiazolidin-4-one scaffold (1; Figure 1). The presence of the elec-

Benzo[d]isothiazol-3-yl-benzamidines: a Class of Protective Agents on Culture of Human Cartilage and Chondrocytes Stimulated by IL-1β

New derivatives of N‐benzo[d]isothiazol‐3‐yl‐benzamidine 6u2009a were synthesized as nonacidic anti‐inflammatory/antidegenerative agents. We investigated the influence of the amidines 6u2009a–j on the production of NO, PGE2, MMP‐3, COX‐2, ROS, and GAGs, key molecules involved in cartilage destruction in osteoarthritic diseases. The antidegenerative properties of the novel designed derivatives 6u2009b–j were improved with respect to N‐benzo[d]isothiazol‐3‐yl‐benzamidine 6u2009a. All of the compounds 6u2009a–j promoted the reduction of most of the IL‐1β‐induced harmful effects. Derivatives 6u2009d, 6u2009h, and 6u2009j were the most potent of all the tested compounds, particularly in the human chondrocyte culture model.

Nanostructured Lipid Carriers (NLC) as Vehicles for Topical Administration of Sesamol: In Vitro Percutaneous Absorption Study and Evaluation of Antioxidant Activity

Sesamol is a natural phenolic compound extracted from Sesamum indicum seed oil. Sesamol is endowed with several beneficial effects, but its use as a topical agent is strongly compromised by unfavorable chemical-physical properties. Therefore, to improve its characteristics, the aim of the present work was the formulation of nanostructured lipid carriers as drug delivery systems for topical administration of sesamol.Two different nanostructured lipid carrier systems have been produced based on the same solid lipid (Compritol® 888 ATO) but in a mixture with two different kinds of oil phase such as Miglyol® 812 (nanostructured lipid carrier-M) and sesame oil (nanostructured lipid carrier-PLUS). Morphology and dimensional distribution of nanostructured lipid carriers have been characterized by differential scanning calorimetry and photon correlation spectroscopy, respectively. The release pattern of sesamol from nanostructured lipid carriers was evaluated in vitro determining drug percutaneous absorption through excised human skin. Furthermore, an oxygen radical absorbance capacity assay was used to determine their antioxidant activity.From the results obtained, the method used to formulate nanostructured lipid carriers led to a homogeneous dispersion of particles in a nanometric range. Sesamol has been encapsulated efficiently in both nanostructured lipid carriers, with higher encapsulation efficiency values (>u200990u200a%) when sesame oil was used as the oil phase (nanostructured lipid carrier-PLUS). In vitro evidences show that nanostructured lipid carrier dispersions were able to control the rate of sesamol diffusion through the skin, with respect to the reference formulations.Furthermore, the oxygen radical absorbance capacity assay pointed out an interesting and prolonged antioxidant activity of sesamol, especially when vehiculated by nanostructured lipid carrier-PLUS.

Nanostructured lipid dispersions for topical administration of crocin, a potent antioxidant from saffron (Crocus sativus L.)

Crocin, a potent antioxidant obtained from saffron, shows anticancer activity in in vivo models. Unfortunately unfavorable physicochemical features compromise its use in topical therapy. The present study describes the preparation and characterization of nanostructured lipid dispersions as drug delivery systems for topical administration of crocin and the evaluation of antioxidant and antiproliferative effects of crocin once encapsulated into nanostructured lipid dispersions. Nanostructured lipid dispersions based on monoolein in mixture with sodium cholate and sodium caseinate have been characterized by cryo-TEM and PCS. Crocin permeation was evaluated in vitro by Franz cells, while the oxygen radical absorbance capacity assay was used to evaluate the antioxidant activity. Furthermore, the antiproliferative activity was tested in vitro by the MTT test using a human melanoma cell line. The emulsification of monoolein with sodium cholate and sodium caseinate led to dispersions of cubosomes, hexasomes, sponge systems and vesicles, depending on the employed emulsifiers. Permeation and shelf life studies demonstrated that nanostructured lipid dispersions enabled to control both rate of crocin diffusion through the skin and crocin degradation. The oxygen radical absorbance capacity assay pointed out an interesting and prolonged antioxidant activity of crocin while the MTT test showed an increase of crocin cytotoxic effect after incorporation in nanostructured lipid dispersions. This work has highlighted that nanostructured lipid dispersions can protect the labile molecule crocin from degradation, control its skin diffusion and prolong antioxidant activity, therefore suggesting the suitability of nanostructured lipid dispersions for crocin topical administration.

Development and in Vitro Evaluation of an Innovative "dietary Flavonoid Supplement" on Osteoarthritis Process

The aim of this study was to evaluate the antidegenerative effect in osteoarthritis damage of eriocitrin alone and eriocitrin formulated as innovative “dietary flavonoid supplement.” A complexation between eriocitrin and hydroxypropyl β-cyclodextrin by solubilization/freeze-drying method was performed. The complex in solution was evaluated by phase solubility studies and the optimal 1u2009:u20092 flavanone/cyclodextrin molar ratio was selected. Hydroxypropyl β-cyclodextrin was able to complex eriocitrin as confirmed by UV-Vis absorption, DSC, and FTIR studies. The complex formed increased the eriocitrin water solubility (from 4.1 ± 0.2u2009g·L−1 to 11.0 ± 0.1u2009g·L−1) and dissolution rate (from 37.0% to 100%) in 30u2009min. The in vitro studies exhibit the notion that eriocitrin and its complex inhibit AGEs in a similar manner because hydroxypropyl β-cyclodextrin does not interfere with the flavanone intrinsic property. Instead, the presence of cyclodextrin improves eriocitrin antioxidant stability maintaining a high fluorescence value until 8 hours with respect to the pure materials. Moreover, hydroxypropyl β-cyclodextrin showed moderate GAGs restoration acting synergistically with the complexed compound to maintain the structural chondrocytes integrity. The results point out that ERT/HP-betaCD complex possesses technological and biological characteristics able to obtain an easily soluble nutraceutical product, which reduces the degenerative and oxidative damage which occurs in osteoarthritis, and improve the patient compliance.