Living Reference Work Entry

Handbook of Sol-Gel Science and Technology

pp 1-42

Date: Latest Version

Biomaterials Obtained by Gelation

  • Alain C. PierreAffiliated withRetired, Institut de recherches sur la Catalyse et l’Environnement de Lyon, CNRS, UMR 5256, Retired, Université Claude Bernard Lyon 1, Université Claude Bernard Lyon 1 Email author 


Biomaterials play a crucial role to improve the quality of life of patients who need a medical implant. The present chapter is focused on those biomaterials which can be made by sol–gel processing and particularly on the developments achieved in the last decade. The chemistry involved in sol–gels permits to drastically improve the properties of biomaterials which are addressed here by order of increased sophistication. In a first section, traditional biomaterials and their synthesis by sol–gel are described. After a brief summary of the properties required for a biomaterial and of sol–gel processing, the materials addressed comprise the calcium phosphates, the so-called bioglasses based on sol–gel silica and their shaping as porous scaffolds, and the organic hydrogels. In a second section, the bioactivity tests applied to biomaterials, as well as the bioactivity mechanisms considered to operate in bioglasses, are summarized. A third section is focused on sol–gel TiO2 based biomaterials, while the next section is dedicated to sol–gel composites and hybrid organic–inorganic gels. The latter group includes a summary of the challenge to introduce calcium in hybrids. A last section concerns the highest present degree of sophistication aimed in biomaterials, which is the entrapment of bioactive molecules in the gels, such as growth factors. The aim is that such additives must be progressively delivered to the surrounding tissues during the lifetime of an implant, so as to improve its biocompatibility for a longer time span.