Development and evaluation of orthopedic bioabsorbable implant products based on chitosan

Lígia Margarida Jorge de Figueiredo

Key information

Authors:

Lígia Margarida Jorge de Figueiredo (Lígia Margarida Jorge de Figueiredo)

Supervisors:

Maria Alexandra Sousa Rodrigues (Maria Alexandra Sousa Rodrigues)

Published in

02/16/2018

Abstract

Bioabsorbable implants play a very important role in orthopedics, due to their capability to degrade over time, avoiding the need for its removal after tissue repair and healing. However, there are still problems to solve such as the biocompatibility of the degradation products which can be addressed using chitosan. This natural occurring polymer has many advantages, such as its biodegradability and biocompatibility properties, and the promotion of tissue regeneration without causing inflammatory reactions. However, for orthopedic applications, chitosan has limited strength, an issue addressed in this thesis by blending chitosan with different groups of materials: plasticizers and ceramics. Hence, different concentrations of these materials were blended with chitosan to produce 3D dense products for orthopedic applications. The plasticizer (10% w/v glycerol) and ceramic (10% w/v glycerol + 10% w/w biphasic mixture of calcium phosphates) blends selected were based on their mechanical properties and ease of machining without breaking, thus allowing different geometries to the final application design. The selected blends were also compared based on the results of biological and sterilization tests; the degradation over 24 weeks and the osteoinduction behaviors were studied and the mechanical, physical, microstructural, chemical and cytotoxic properties were analyzed before and after the use of different sterilization methods