new polymeric materials. Examples of that are hydrogels for controlled release of drugs. In this work, hydrogels of poly (N-2-vinil-pyrrolidone) (PVP) containing chitosan and clay nanoparticles were obtained and characterized to investigate chitosan influence on Glucantime drug delivery. The matrixes were crosslinked by gamma irradiation process with doses of 25 kGy. Hydrogels morphologies were observed by X Ray diffraction (DRX). Atomic Force Microscopy (AFM) and swelling kinetic at 22 °C to study the capacity of water retention and, finally, drug delivery tests were performed 'in vitro'. The system showed higher gel fraction for the matrix with 1.0% of clay and 0.5% of chitosan. In this case, besides the interactions of clay ions with PVP, there are interactions of chitosan amine group with PVP amide group. (author)
Etrych, Tomáš; Lucas, Henrike; Janoušková, Olga; Chytil, Petr; Mueller, Thomas; Mäder, Karsten
In the past several decades, nanosized drug delivery systems with various targeting functions and controlled drug release capabilities inside targeted tissues or cells have been intensively studied. Understanding their pharmacokinetic properties is crucial for the successful transition of this research into clinical practice. Among others, fluorescence imaging has become one of the most commonly used imaging tools in pre-clinical research. The development of increasing numbers of suitable fluorescent dyes excitable in the visible to near-infrared wavelengths of the spectrum has significantly expanded the applicability of fluorescence imaging. This paper focuses on the potential applications and limitations of non-invasive imaging techniques in the field of drug delivery, especially in anticancer therapy. Fluorescent imaging at both the cellular and systemic levels is discussed in detail. Additionally, we explore the possibility for simultaneous treatment and imaging using theranostics and combinations of different imaging techniques, e.g., fluorescence imaging with computed tomography. Copyright © 2016 Elsevier B.V. All rights reserved.
Assa, Farnaz; Jafarizadeh-Malmiri, Hoda; Ajamein, Hossein; Vaghari, Hamideh; Anarjan, Navideh; Ahmadi, Omid; Berenjian, Aydin
The potential of magnetic nanoparticles (MNPs) in drug delivery systems (DDSs) is mainly related to its magnetic core and surface coating. These coatings can eliminate or minimize their aggregation under physiological conditions. Also, they can provide functional groups for bioconjugation to anticancer drugs and/or targeted ligands. Chitosan, as a derivative of chitin, is an attractive natural biopolymer from renewable resources with the presence of reactive amino and hydroxyl functional groups in its structure. Chitosan nanoparticles (NPs), due to their huge surface to volume ratio as compared to the chitosan in its bulk form, have outstanding physico-chemical, antimicrobial and biological properties. These unique properties make chitosan NPs a promising biopolymer for the application of DDSs. In this review, the current state and challenges for the application magnetic chitosan NPs in drug delivery systems were investigated. The present review also revisits the limitations and commercial impediments to provide insight for future works.
Oliveira, Maria J.A.; Lugao, Ademar B.; Parra, Duclerc F.; Amato, Valdir S.
The current study of polymer science considers the area of biomedical application very important to establish developments in new polymeric materials. Examples of that are hydrogels for controlled release of drugs. In this work, hydrogels of poly (N-2-vinil-pyrrolidone) (PVP) containing chitosan and clay nanoparticles were obtained and characterized to investigate chitosan influence on Glucantime drug delivery. The matrixes were crosslinked by gamma irradiation process with doses of 25 kGy. Hydrogels morphologies were observed by X Ray diffraction (DRX). Atomic Force Microscopy (AFM) and swelling kinetic at 22 °C to study the capacity of water retention and, finally, drug delivery tests were performed 'in vitro'. The system showed higher gel fraction