Three-dimensional structures obtained by complexation of chitosan with other polysaccharides for application in vascular tissue engineering

Author(s)

Fernanda Carla Bombaldi de Souza

• Document type: Doctoral Thesis
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Engenharia Química
• Defense date: 2018-10-09

Examining board members

Angela Maria Moraes; Bradley D Olsen; Kamilla Swiech Antonietto; Roberto Dalto Fanganiello; Wirla Maria da Silva Cunha Tamashiro

• Advisor: Angela Maria Moraes; Diego Mantovani

Abstract

Cardiovascular diseases such as coronary artery and peripheral vascular diseases are the leading cause of death worldwide. Surgical interventions for the repair of damaged blood vessels are often necessary, including partial replacement of the vessel or use of vascular patches. There is a need for materials capable of acting effectively as vascular substitutes, especially in the case of small-caliber blood vessels (diameter smaller than 6 mm), since the materials regularly used often lead to postoperative complications and vessel reocclusion. Recent advances in the development of vascular substitutes are a consequence of tissue engineering approaches, with the culture of vascular cells on biodegradable scaffolds. Chitosan (Ch), a natural biocompatible polymer, is widely used in the production of scaffolds and its combination with other polysaccharides such as alginate (A) and pectin (P) contributes to the improvement of biomaterial properties. In this work, matrices with flat geometry were produced using chitosan of three different molar weights in combination with A or P in the presence or absence of the surfactant Kolliphor® P188 (K) and silicone gel Silpuran® 2130 A/B (S), and characterized to assess the influence of composition on matrix¿s properties. Additional characterizations were performed to validate their potential application as tissue-engineered vascular patches. The use of chitosan of high molar weight and pectin, in combination with S, resulted in materials with poroviscoelastic behavior and higher mechanical resistance when comparing all formulations tested. Ch-P matrices presented higher stability and better response to blood contact, due to the presence of platelets in the less advanced stages of activation and lower levels of thrombogenicity, as well as better adhesion, proliferation and greater viability of smooth muscle cells. Devices with tubular geometry prepared with Ch-P were successfully fabricated using a new methodology, resulting in homogeneous, stable and highly porous scaffolds. The use of collagen gel for entrapment of smooth muscle cells facilitated the introduction and homogeneous distribution of the cells in the three-dimensional tubular structure. The present study evidenced that the use of chitosan complexed with pectin, a combination still underexplored in tissue engineering, has the potential to be further investigated for this purpose. In addition, this study demonstrated that the three-dimensional structures obtained in different geometries are promising for the use in the reconstruction and regeneration of vascular tissues (AU)

• FAPESP's process: 13/26534-1 - Chitosan-based tissue engineered vascular grafts
• Grantee: Fernanda Carla Bombaldi de Souza
• Support Opportunities: Scholarships in Brazil - Doctorate