Tiny technology proves big: a challenge at engineering, medicine and pharmaceutical sciences interface

Nano and microparticle drug delivery systems for the treatment of Brucella infections

Nano-based drug delivery systems are increasingly used for diagnosis, prevention and treatment of several diseases, thanks to several beneficial properties, including the ability to target specific cells or organs, allowing to reduce treatment costs and side effects frequently associated with chemotherapeutic medications, thereby improving treatment compliance of patients. In the field of communicable diseases, especially those caused by intracellular bacteria, the delivery of antibiotics targeting specific cells is of critical importance to maximize their treatment efficacy. Brucella melitensis, an intracellular obligate bacterium surviving and replicating inside macrophages is hard to be eradicated, mainly because of the low ability of antibiotics to enter these phagocityc cells . Although different antibiotics regimens including gentamicin, doxycycline and rifampicin are in fact used against the Brucellosis, no efficient treatment has been attained yet, due to the intracellular life of the respective pathogen. Nano-medicines responding to environmental stimuli allow to maximize drug delivery targeting macropages, thereby boosting treatment efficacy. Several drug delivery nano-technologies, including solid lipid nanoparticles, liposomes, chitosan, niosomes, and their combinations with chitosan sodium alginate can be employed in combination of antibiotics to successfully eradicate Brucellosis infection from patients.

Biodegradable and pH-Responsive Acetalated Dextran (Ac-Dex) Nanoparticles for NIR Imaging and Controlled Delivery of a Platinum-Based Prodrug into Cancer Cells

Nanoparticles (NPs) based on the biodegradable acetalated dextran polymer (Ac-Dex) were used for near-infrared (NIR) imaging and controlled delivery of a Pt^IV prodrug into cancer cells. The Ac-Dex NPs loaded with the hydrophobic Pt^IV prodrug 3 (Pt^IV/Ac-Dex NPs) and with the novel hydrophobic NIR-fluorescent dye 9 (NIR-dye 9/Ac-Dex NPs), as well as Ac-Dex NPs coloaded with both compounds (coloaded Ac-Dex NPs), were assembled using a single oil-in-water nanoemulsion method. Dynamic light scattering measurements and scanning electron microscopy images showed that the resulting Ac-Dex NPs are spherical with an average diameter of 100 nm, which is suitable for accumulation in tumors via the enhanced permeation and retention effect. The new nanosystems exhibited high drug-loading capability, high encapsulation efficiency, high stability in physiological conditions, and pH responsiveness. Drug-release studies clearly showed that the Pt^IV prodrug 3 release from Ac-Dex NPs was negligible at pH 7.4, whereas at pH 5.5, this compound was completely released with a controlled rate. Confocal laser scanning microscopy unambiguously showed that the NIR-dye 9/Ac-Dex NPs were efficiently taken up by MCF-7 cells, and cytotoxicity assays against several cell lines showed no significant toxicity of blank Ac-Dex NPs up to 1 mg mL^-1. The IC₅₀ values obtained for the Pt^IV prodrug encapsulated in Ac-Dex NPs were much lower when compared with the IC₅₀ values obtained for the free Pt^IV complex and cisplatin in all cell lines tested. Overall, our results demonstrate, for the first time, that Ac-Dex NPs constitute a promising drug delivery platform for cancer therapy.

Impact of semi-solid formulations on skin penetration of iron oxide nanoparticles

Background

This work aimed to provide useful information on the incidence of the choice of formulation in semi-solid preparations of iron-oxide nanoparticles (IONs). The appropriate analytical methods to assess the IONs physical stability and the effect of the semi-solid preparations on IONs human skin penetration were discussed. The physical stability of IONs (D_h = 31 ± 4 nm; ζ = −65 ± 5 mV) loaded in five semi-solid preparations (0.3% w/v), namely Carbopol gel (CP), hydroxyethyl cellulose gel (HEC), carboxymethylcellulose gel (CMC), cetomacrogol cream (Cet) and cold cream was assessed by combining DLS and low-field pulsed NMR data. The in vitro penetration of IONs was studied using human epidermis or isolated stratum corneum (SC).

Results

Reversible and irreversible IONs aggregates were evidenced only in HEC and CMC, respectively. IONs diffused massively through SC preferentially by an intercellular pathway, as assessed by transmission electron microscopy. The semi-solid preparations differently influenced the IONs penetration as compared to the aqueous suspension. Cet cream allowed the highest permeation and the lowest retained amount, while cold cream and CP favored the accumulation into the skin membrane.

Conclusion

Basic cutaneous semi-solid preparations could be used to administer IONs without affecting their permeation profile if they maintained their physical stability over time. This property is better discriminated by low-field pulsed NMR measurements than the commonly used DLS measurements.

Electronic supplementary material

The online version of this article (doi:10.1186/s12951-017-0249-6) contains supplementary material, which is available to authorized users.

Nanotechnological approaches for the effective management of psoriasis

Psoriasis is a chronic disorder with erythematous scaly patches, which typically affects the exposed surfaces of the body and scalp. Various factors such as bacterial infection, genetic and environmental factors, and immune disorders play an important role in causing psoriasis. Different types of psoriasis can be observed, such as guttate psoriasis, inverse psoriasis, pustular psoriasis, and psoriatic arthritis. Various ancient, topical, and systemic approaches have been used to control the disease, but have failed to achieve a complete reduction of the disease, besides causing toxic effects. Therefore, our main aim in this review article is to introduce the different advanced nanotechnological approaches for effective treatment of psoriasis.

Eudragit nanoparticles loaded with silybin: a detailed study of preparation, freeze-drying condition and in vitro/in vivo evaluation

The objective of this work was use of silybin nanoparticles in treatment of ulcerative colitis (UC). Eudragit RL PO nanoparticles loaded with silybin were produced using solvent-evaporation emulsification technique. Then, they were coated by Eudragit FS30D. Drug release was studied in different physiological environments. Colitis was induced by 4% of acetic acid in rats which received freeze-dried nanoparticles of silybin (75 mg/kg/day), dexamethasone (1 mg/kg/day), blank nanoparticles and normal saline orally for 5 days. Then macroscopic, histopathological evaluation and biochemical analysis, including myeloperoxidase (MPO) activity, tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) levels in colon tissues were determined using enzyme-linked immunosorbent assay (ELISA) kits. Macroscopic and histopathological scores were improved by the optimised nanoparticles. The optimised nanoparticles had a particle size of 109 ± 6 nm, zeta potential of 15.4 ± 2 mV, loading efficiency of 98.3 ± 12% and release efficiency of 40.8 ± 5.5% at 24 h. TNF-α, IL-6 and MPO activity were reduced significantly by nanoparticles compared to control group (p < 0.05).