Search

Osteosarcoma (OSA) is a bone cancer that affects both humans and animals, with dogs being particularly vulnerable. Standard therapy is often limited by multidrug resistance (MDR), primarily due to the overexpression of P-glycoprotein (P-gp), which expels drugs from the cells, reducing their efficacy. To overcome this challenge, drug delivery systems (DDS) and P-gp modulators have been explored. However, developing DDS that selectively target cancer cells remains difficult, with many current options lacking efficiency. Our research group has recently developed an innovative type of nanoparticle with a lipid core and a calcium phosphate shell (CaP-NPs), which enhances the uptake of doxorubicin (DOXO) in OSA cells. In this study, we loaded a lipophilic ester of doxorubicin (C12DOXO) and curcumin (CURC), a natural P-gp modulator, into CaP-NPs and co-incubated them into human and canine OSA cell lines, including DOXO-resistant cells. The results demonstrated a significant reduction in viability in human OSA cells. Additionally, the combination treatment led to a further increase in C12DOXO retention when cells were also treated with the P-gp inhibitor verapamil, indicating enhanced efficacy against MDR mechanisms. Notably, canine OSA cells exhibited a distinct response pattern, suggesting the presence of species-specific differences that warrant further investigation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Several semisynthetic, low-cardiotoxicity doxorubicin (DOXO) conjugated have been extensively described, considering the risk of cytotoxicity loss against resistant tumor cells, which mainly present drug efflux capacity. Doxorubicin 14-[4-(4-phenyl-5-thioxo-5H-[1,2]dithiol-3-yl)]-benzoate (H 2 S-DOXO) was synthetized and tested for its ability to overcome drug resistance with good intracellular accumulation. In this paper, we present a formulation study aimed to develop naked and decorated H 2 S-DOXO-loaded lipid nanoparticles (NPs). NPs prepared by the "cold dilution of microemulsion" method were decorated with hyaluronic acid (HA) to obtain active targeting and characterized for their physicochemical properties, drug entrapment efficiency, long-term stability, and in vitro drug release. Best formulations were tested in vitro on human-sensitive (MCF7) and human/mouse DOXO-resistant (MDA-MDB -231 and JC) breast cancer cells, on human (U-2OS) osteosarcoma cells and DOXO-resistant human/mouse osteosarcoma cells (U-2OS/DX580/K7M2). HA-decoration by HA-cetyltrimethyl ammonium bromide electrostatic interaction on NPs surface was confirmed by Zeta potential and elemental analysis at TEM. NPs had mean diameters lower than 300 nm, 70% H 2 S-DOXO entrapment efficiency, and were stable for almost 28 days. HA-decorated NPs accumulated H 2 S-DOXO in Pgp-expressing cells reducing cell viability. HA-decorated NPs result in the best formulation to increase the inter-cellular H 2 S-DOXO delivery and kill resistant cells, and therefore, as a future perspective, they will be taken into account for further in vivo experiments on tumor animal model.

Chitosan is an excipient which has been studied thoroughly in research works thanks to its positive characteristics such as muco-adhesiveness and ability to open epithelial-tight-junctions. In this article, lipophilic stearoyl chitosan (ST-CS) was synthetized in order to anchor this polymer to lipid nanoparticles and prepare ST-CS-coated nanoparticles (ST-CS-NP) using the microemulsion cold dilution technique. Curcumin (CURC) was used as model drug. CURC-ST-CS-NP were characterized by dimensional analysis, zeta potential, drug entrapment, drug release; tested in vitro on Human Umbilical Vein Endothelial Cell (HUVEC) cells to study its cytotoxicity and on human pancreatic cancer cells (PANC-1) to determine inhibition ability; tested in rats to determine CURC blood profiles and biodistribution. CURC-ST-CS-NP had mean diameters in the range 200⁻400 nm and CURC entrapment up to 73%. These systems did not show cytotoxicity on HUVEC cells at all tested dilutions and revealed to be more effective than free CURC solution on PANC-1 cells at 5 and 10 µM CURC. Blood profile studies evidenced as CURC entrapment in NP prolonged the permanence of drug in the systemic circulation compared to CURC solution due to a certain stealth property of NP, probably attributable to hydrophilic chitosan coating. Biodistribution studies showed a smaller CURC concentration in RES organs when CURC-ST-CS-NP were administered.

Floxuridine is a very effective drug with high potency in the treatment of various tumors but its utility is limited by its low efficiency of cellular uptake. In order to improve the floxuridine efficiency of cellular uptake, lipophilic prodrug of floxuridine (3',5'-distearoyl-5-fluoro-2'-deoxyuridine) was synthetized and loaded into behenic acid nanoparticles produced by fatty acid coacervation technique. Generally, spherical shaped SLN with mean diameters below 300 nm were obtained. Distearoyl-floxuridine was loaded in SLN with high entrapment efficiency (from 70.8 to 82.8%). In Vitro cytotoxicity studies on different human cancer cell lines (M14, HT-29 and MDA-MB231) were performed in order to test the ability of distearoyl-floxuridine-SLN to inhibit the cancer cell growth. In MTT test distearoyl floxuridine SLN showed a greater efficacy than floxuridine on all cancer cell lines revealing an efficiency about 100 times higher. Also clonogenic assay showed a higher cytotoxicity of distearoyl-floxuridine-SLN compared to floxuridine but the difference between the formulations was only about 10 times. In conclusion, SLN proved to be a promising vehicle to increase the floxuridine efficacy in cancer therapy.

Aim: Methotrexate-loaded biocompatible nanoparticles were tested for preliminary efficacy in glioma treatment., Materials & Methods: Behenic acid nanoparticles, prepared by the coacervation method, were loaded with the ester prodrug didodecylmethotrexate, which was previously tested in vitro against glioblastoma human primary cultures. Nanoparticle conjugation with an ApoE mimicking chimera peptide was performed to obtain active targeting to the brain., Results & Conclusion: Biodistribution studies in healthy rats assessed the superiority of ApoE-conjugated formulation, which was tested on an F98/Fischer glioma model. Differences were observed in tumor growth rate (measured by MRI) between control and treated rats. In vitro tests on F98 cultured cells assessed their susceptibility to treatment, with consequent apoptosis, and allowed us to explain the apoptosis observed in glioma models.

Doxorubicin (DOXO) lauroyl ester and amide were proposed as lipophilic derivatives and entrapped in SLNs. DOXO derivatives-loaded SLNs were spherical shaped, had 200-300 nm mean diameters and showed 80-94% w/w drug entrapment efficiencies. The effect of DOXO derivatives-loaded SLNs and free DOXO on cell growth was examined by MTT and colony-forming assays on four different tumour cell lines: a pancreatic, CFPAC-1, a lung, A549, and two ovarian, A2780 and A2780res (DOXO-resistant). The results obtained with MTT and colony-forming assay show that although DOXO displayed an inhibition of cell proliferation greater or similar to DOXO lauroyl amide-loaded SLNs on all cell types, the effect induced by DOXO lauroyl ester-loaded SLNs was higher and concentration-dependent, and it was the only one maintained at 10(-5 )mM concentration. Only DOXO lauroyl ester-loaded SLNs were able to induce a 40% inhibitory effect on A2780 res cell line up to 10(-4 )mM concentration.

Glioblastoma, the most common primary brain tumor in adults, has an inauspicious prognosis, given that overcoming the blood-brain barrier is the major obstacle to the pharmacological treatment of brain tumors. As neoangiogenesis plays a key role in glioblastoma growth, the US Food and Drug Administration approved bevacizumab (BVZ), an antivascular endothelial growth factor antibody for the treatment of recurrent glioblastoma in patients whose the initial therapy has failed. In this experimental work, BVZ was entrapped in solid lipid nanoparticles (SLNs) prepared by the fatty-acid coacervation technique, thanks to the formation of a hydrophobic ion pair. BVZ activity, which was evaluated by means of four different in vitro tests on HUVEC cells, increased by 100- to 200-fold when delivered in SLNs. Moreover, SLNs can enhance the permeation of fluorescently labelled BVZ through an hCMEC/D3 cell monolayer-an in vitro model of the blood brain barrier. These results are promising, even if further in vivo studies are required to evaluate the effective potential of BVZ-loaded SLNs in glioblastoma treatment.

Central nervous system disorders are already prevalent and steadily increasing among populations worldwide. However, most of the pharmaceuticals present on world markets are ineffective in treating cerebral diseases, because they cannot effectively cross the blood brain barrier (BBB). Solid lipid nanoparticles (SLN) are nanospheres made from biocompatible solid lipids, with unique advantages among drug carriers: they can be used as vehicles to cross the BBB. This review examines the main aspects surrounding brain delivery with SLN, and illustrates the principal mechanisms used to enhance brain uptake of the delivered drug., (Copyright © 2014 Elsevier B.V. All rights reserved.)

The major obstacle to glioblastoma pharmacological therapy is the overcoming of the blood-brain barrier (BBB). In literature, several strategies have been proposed to overcome the BBB: in this experimental work, solid lipid nanoparticles (SLN), prepared according to fatty acid coacervation technique, are proposed as the vehicle for doxorubicin (Dox), to enhance its permeation through an artificial model of BBB. The in vitro cytotoxicity of Dox-loaded SLN has been measured on three different commercial and patient-derived glioma cell lines. Dox was entrapped within SLN thanks to hydrophobic ion pairing with negatively charged surfactants, used as counterions. Results indicate that Dox entrapped in SLN maintains its cytotoxic activity toward glioma cell lines; moreover, its permeation through hCMEC/D3 cell monolayer, assumed as a model of the BBB, was increased when the drug was entrapped in SLN. In conclusion, SLN proved to be a promising vehicle for the delivery of Dox to the brain in glioblastoma treatment., (© 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.)

Several topical products contain nanometric TiO2 (nano-TiO2), which is a useful and safe component that absorbs UV light and does not cross skin barrier. However, nano-TiO2 may impregnate the first layer of the skin (stratum corneum, SC) and generate free radicals, even under low UV irradiation. These properties, largely dependent on TiO2 surface chemistry, may modulate the transdermal drug permeation. To investigate how TiO2 surface properties affect drug permeation, amphotericin in two different media, in the presence of three differently coated samples, was applied on skin and the flux measured. The naked, but not the coated, nano-TiO2 showed enhancer property, with a fourfold increase of the drug flux. Only the positively-charged, naked TiO2 strongly adhered to and altered the SC structure. The oxidative potential towards formate anion and linoleic acid was assessed and a molecular mechanism to elucidate increased skin permeability proposed. To enhance the drug permeation, both a surface charge-driven adhesion and an oxidative disorganization of the SC lipids are required. By modulating TiO2 surface charge (coating) and its oxidative potential (crystalline phase), the enhancer effect of nano-TiO2 may be tuned and turned up or down when transdermal penetration of drug has to be favored or impaired., (Copyright © 2014 Elsevier B.V. All rights reserved.)

FMOC-isocyclosporine A, a fluorescent labeled cyclosporine A, was encapsulated in solid lipid nanoparticles (SLN) prepared by the coacervation technique, and its anti-inflammatory activity was evaluated. The anti-inflammatory activity of the fluorescent labelled molecule, measured as inhibition of TNF-α secretion, is similar to the native one. SLN were compared to commercial formulations, through measurement of cytokine release and drug uptake in rat peripheral blood mononuclear cells. Drug-loaded SLN inhibit TNF-α secretion in a lower extent than commercial formulations, probably due to a lower uptake by the cells, but the increase of IL-10 secretion caused by the lipid matrix itself makes this formulation interesting for its anti-inflammatory activity.

Curcumin (CU) loaded solid lipid nanoparticles (SLNs) of fatty acids (FA) were prepared with a coacervation technique based on FA precipitation from their sodium salt micelles in the presence of polymeric non-ionic surfactants. Myristic, palmitic, stearic, and behenic acids, and different polymers with various molecular weights and hydrolysis grades were employed as lipid matrixes and stabilisers, respectively. Generally, spherical-shaped nanoparticles with mean diameters below 500 nm were obtained, and using only middle-high hydrolysis, grade-polymer SLNs with diameters lower than 300 nm were produced. CU encapsulation efficiency was in the range 28-81% and highly influenced by both FA and polymer type. Chitosan hydrochloride was added to FA SLN formulations to produce bioadhesive, positively charged nanoparticles. A CU-chitosan complex formation could be hypothesised by DSC analysis, UV-vis spectra and chitosan surface tension determination. A preliminary study on HCT-116 colon cancer cells was developed to evaluate the influence of CU-loaded FA SLNs on cell viability.

A method to produce solid lipid nanoparticles (SLN) from W/O/W multiple emulsions was developed applying the solvent-in-water emulsion-diffusion technique. Insulin was chosen as hydrophilic peptide drug to be dissolved in the acidic inner aqueous phase of multiple emulsions and to be consequently carried in SLN. Several partially water-miscible solvents with low toxicity were screened in order to optimize emulsions and SLN composition, after assessing that insulin did not undergo any chemical modification in the presence of the different solvents and under the production process conditions. SLN of spherical shape and with mean diameters in the 600-1200 nm range were obtained by simple water dilution of the W/O/W emulsion. Best results, in terms of SLN mean diameter and encapsulation efficiencies, were obtained using glyceryl monostearate as lipid matrix, butyl lactate as a solvent, and soy lecithin and Pluronic F68 as surfactants. Encapsulation efficiencies up to 40% of the loaded amount were obtained, owing to the actual multiplicity of the system; the use of multiple emulsion-derived SLN can be considered a useful strategy to encapsulate a hydrophilic drug in a lipid matrix.