The influence of spatial distribution on add-on therapy of designed Ca-Alg/CS MEMs system

Progress in the Development of Chitosan Based Insulin Delivery Systems: A Systematic Literature Review

Diabetes mellitus is a chronic disease that is considered a worldwide epidemic, and its control is a constant challenge for health systems. Since insulin had its first successful use, scientists have researched to improve the desired effects and reduce side-effects. Over the years, the challenge has been to increase adherence to treatment and improve the quality of life for diabetics by developing an insulin delivery system. This systematic review (SR) analyses experimental articles from 1998 to 2018 related to the development of the chitosan/insulin delivery system (CIDS). Automated support: Start tool was used to perform part of these activities. The search terms “insulin”, “delivery or release system”, and “chitosan” were used to retrieve articles in PubMed, Science Direct, Engineering Village, and HubMed. A total of 55 articles were selected. The overview, phase, model, way of administration, and the efficiency of CIDS were analyzed. According to SR results, most of the articles were published from 2010 onwards, representing 72.7% of the selected papers, and research groups from China publicized 23.6% of the selected articles. According to the SR, 51% of the studies were carried out in vivo and 45% in vitro. Most of the systems were nanoparticle based (54.8%), and oral administration was proposed by 60.0% of the selected articles. Only 36.4% performed loaded capacity and encapsulation efficiency assays, and 24 h (16.4%), 12 h (12.7%), and 6 h (11.0%) were the most frequent insulin release times. Chitosan’s intrinsic characteristics, which include biodegradability, biocompatibility, adhesiveness, the ability to open epithelial tight junctions to allow an increase in the paracellular transport of macromolecular drugs, such as insulin, and the fact that it does not result in allergic reactions in the human body after implantation, injection, topical application or ingestion, have contributed to the increase in research of CIDS over the years. However, the number of studies is still limited and the use of an alternative form of insulin administration is not yet possible. Thus, more studies in this area, aiming for the development of an insulin delivery system that can promote more adherence to the treatment and patient comfort, are required.

Bioactive nanoparticle embedded microcapsules for improving the efficacy of type I diabetes therapy

In order to overcome the side effects of pancreatic transplantation and insulin injection treatment for type I diabetes, we established a drug delivery system employing nanoparticle embedded microcapsules (NEMs). The system co-encapsulated chitosan nanoparticles with γ-aminobutyric acid and β-TC-6 cells for combined drug and cell therapy in diabetes mellitus (DM). The NEMs, which were formed via high-voltage electrostatic method, had an excellent sphericity with a smooth surface. The average size NEM was 245.52 ± 22.00 μm, which indicated a good size for cell encapsulation. Haemolysis rate of NEMs at concentrations of 100, 200 or 300 mg/mL were all below 5%. Relative viability rates of L929 cells with the same concentrations at 24, 48 or 72 h were all above 80%. We implanted bioactive NEMs into type 1 DM mice to evaluate the effect of the combined therapy. The level of blood glucose in the group receiving the combined therapy decreased during the first 2 weeks of treatment. During the next week, the level of blood glucose stayed in a safe range. Body weight continuously increased during the postoperative period after combined therapy group. Oral glucose tolerance test (OGTT) performed after 24 d showed that the level of blood glucose combined therapy reached the maximum peak of 13.04 mmol/L, lower than 16.56 mmol/L for the cell therapy group. This primary study indicated that microencapsulation technology and combined therapy are promising for the treatment of type I diabetes mellitus.