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EN
Chitosan (Chi) is an extremely promising natural biopolymer with remarkable potency for the development of drug and vaccine delivery nanosystems. Various Chi derivatives are used to form nanoparticles (NPs) with unique properties. However, the efficacy of the therapy delivered by Chi NPs depends significantly on NP biodistribution in the body. The aim of this study was the analysis of biodistribution of NPs formed by succinoyl Chi and loaded with doxorubicin (SCNPDOX). We compared the distribution of free DOX and SCNP-DOX after intravenous (i.v.) and intranasal (i.n.) delivery into tumour-bearing mice. Distribution of DOX and SCNP-DOX was comparable after i.v. injection while they differed significantly after i.n. instillation.
EN
Chitosan is one of the most promising polymers for biomedical applications due to its unique properties, such as its biocompatibility, low toxicity, biodegradation, and the presence of reactive amino and hydroxyl groups. Analysis of physicochemical properties of chitosan and its derivatives is a time-consuming process and requires expensive equipment and large amounts of the sample. This paper proposes a method for express analysis of the molecular weight (MW), the degree of deacetylation (DD), the substitution degree (SD), and the charge of chitosan and its derivatives using agarose gel electrophoresis under acidic and neutral conditions with Coomassie staining. Positively charged chitosan samples required acidic Tris Acetate-EDTA (TAE) buffer to move in the gel. The electrophoretic mobility of chitosan depended on MW, DD, SD, and the chitosan charge. Based on the dependences obtained by the proposed method, the MW and DD of commercial chitosan samples were determined. Express analysis of chitosan and its derivatives in agarose gel can be used to monitor the reactions of chitosan modification and to analyse samples with unknown characteristics.
EN
An increase in the number and volume of surgical interventions leads to an increase in the frequency of postoperative adhesions. The development of the adhesion process in the abdominal cavity causes pain, a decrease in the quality of life of patients, a violation of the reproductive function of women as well as acute adhesion intestinal obstruction. Recently, polymer biomaterials, including those based on chitosan, have been widely used for the prevention of adhesions. Due to their biocompatibility and biodegradation ability, they do not require repeated operations to extract the material. It is believed that these materials act as barriers, physically separating the damaged surfaces. The molecular mechanism of their action is still poorly understood. In this review, the main mechanisms of adhesion formation, as well as ways to prevent them with the help of materials based on chitosan and its derivatives, are discussed
EN
In modern medicine, many diseases can be treated using gene therapy, which requires a DNA delivery system to prevent DNA from degradation and to transport it to the cells. Liposomal reagents are expensive for such a therapy and new inexpensive biodegradable DNA carriers are required. Chitosan (Ch) is a cationic polymer with promising potency for gene delivery. Some Ch derivatives have been shown to efficiently transfect mammalian cells in vitro. However, there are many inconsistencies in the literature concerning the effectiveness of Ch systems for in vivo gene transfer. The aim of this work was to develop a Ch-based vector for in vivo delivery of a large-size DNA fragment coding for the far-red fluorescent protein (RFP). Among several Ch derivatives, hexanoyl-Ch (HCh) with a molecular weight of 20 kDa effectively transfected cells in vitro. Intratumoural injection of polyplexes in colon and lung tumours resulted in local expression of RFP in tumours.
EN
Chitosan is a highly versatile biopolymer characterised by low toxicity, biocompatibility, and slow but complete biodegradation in the human body, possessing multiple reactive groups. One of the most well-known properties of positively charged chitosan derivatives is their ability to bind mucous membranes. The aim of this work was the analysis of mucoadhesion of unmodified 20 kDa chitosan and its hydrophobic (HC) and hydrophobic quaternised (QHC) derivatives in vitro and ex vivo. Unmodified chitosan formed large aggregates in vitro in keratinocyte and colon cell cultures and ex vivo in murine small intestine and muscle explants. At the same time, HC and especially QHC bound cells in vitro and ex vivo in a fine dotted manner, as evidenced by confocal microscopy. Such a pattern of hydrophobic derivatives distribution provides the possibility to develop mucoadhesive drug delivery systems with increased local drug release and improved chitosan biodegradation.
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