Evaluation of the co-encapsulation of curcumin and polymeric nanoparticles containing mesalazine in retrograded starch microparticles intended for colon-specific release

• Grant number: 21/02871-5
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: August 01, 2023
• End date: November 25, 2025
• Field of knowledge: Health Sciences - Pharmacy - Pharmaceutical Technology
• Principal Investigator: Marlus Chorilli
• Grantee: Amanda Letícia Polli Silvestre
• Host Institution: Faculdade de Ciências Farmacêuticas (FCFAR). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil
• Associated scholarship(s): 23/13044-8 - Evaluation of the anti-inflammatory activity of mucoadhesive sodium alginate and chitosan nanoparticles containing mesalazine in a 3D model of multilayer intestinal inflammation, BE.EP.DR

Abstract

Inflammatory bowel diseases (IBD) are chronic inflammations characterized by ulceration and hemorrhage in the mucosa of the gastrointestinal tract (GIT), mainly in the colonic region. They don't have a well-established cause; however, genetic, immunological, and environmental factors can generate greater susceptibility to this disease. IBDs are characterized by periods of remission and relapses and cause various uncomfortable symptoms and pain to the patient, which can lead to more severe clinical conditions and a greater probability for the development of colorectal cancer. The drug of choice for the treatment of mild to moderate IBD is mesalazine (MLZ), an anti-inflammatory that belongs to the class of aminosalicylates. Despite having a different mechanism of action, curcumin (CUR), a natural molecule derived from the Curcuma longa plant, has a well-known anti-inflammatory property and has been widely studied for the treatment of IBD and as a possible strategy in the synergistic treatment for colon release. specific. However, CUR and MLZ have limitations, such as the low solubility and bioavailability of CUR, inactivation of MLZ after absorption in the upper portions of the GIT, so that a part of the drug does not reach the colonic region, impacting the therapeutic effect. Therefore, several strategies have been considered to targeting drugs for the colon, such as the use of prodrugs, the development of pH and/or time-dependent systems, as well as those activated by the colonic microbiota. Among the reported approaches, the development of systems activated by the colonic microbiota has been the most reliable strategy to release drugs in the affected colon. An example of a material that undergoes specific digestion by the enzymes of the colonic microbiota is retrograded starch (AR), a modified starch that escapes digestion in the upper portions of the GIT, being digested only upon reaching the colon, which is why it can be considered an excellent strategy for the development of carriers for colon-specific release. In this sense, the co-encapsulation of CUR and polymeric nanoparticles (NPs) containing MLZ in AR microparticles (MP) is a more relevant and safer strategy for the local treatment of IBD. Besides, the use of micro/nanostructured systems protects against enzymatic action, light, and pH to overcome the limitations of drugs and enhance the therapeutic effect. The present study aims to evaluate the co-encapsulation of CUR and Chitosan NPs (QS) and sodium alginate (AS) containing MLZ in MP of AR intended for colon-specific release. The NPs and MPs will be characterized in terms of size, polydispersity, zeta potential, and shape by scanning electron microscopy. Analytical methodologies will be validated for quantification and determination of the encapsulation efficiency of CUR and MLZ in nano and microstructured systems, which will also be evaluated regarding the thermal profile by differential scanning calorimetry and thermogravimetry. The final system (MP_AR / P-CUR / NPs_MLZ) will be submitted to in vitro release studies and in vitro and in vivo biological tests to prove the performance and effectiveness of the proposed system. It is hoped, therefore, to obtain a system that provides stability for drugs and that allows the targeting of the release of CUR and NPs_MLZ in the affected colon, in order to offer a synergistic and more effective therapy for patients affected by IBD, also contributing to preventing recurrences and the risk of colorectal cancer. (AU)