Porous scaffolds for bone tissue engineering: geometric characteristics, use requirements, materials and additive manufacturing methods

Materials with an internal porous structure that replace damaged bone and serve as scaffolds for regenerative processes are a fundamental tool in bone tissue engineering. In recent years, research has been carried out on the internal geometry that scaffolding must have in order to respond to specific requirements. The objective of this review is to show the biomaterials and additive manufacturing methods that are used in the manufacture of scaffolds, the main geometric characteristics of the cells that make up the cellular materials, the ways that these cells are distributed in space, among others. For the systematic review, the Google Scholar database was consulted. For this, the terms in English were used: bone tissue engineering scaffold geometric design. The inclusion criteria were that the documents were in English and had been published from 2018 onwards. The first 200 results were reviewed and those that were review articles were prioritized. The importance of pore size and porosity percentage was highlighted as the geometric properties that most influence the mechanical, biological and permeability properties of the scaffold. It shows how current research tends towards degradable biomaterials that can generate a response in the tissue that grows on them and the design of structures where the search for a required property guides the design of the scaffold through procedural or optimization methods, which represents a change compared to the study of one or more cells to establish if their properties conformed to what was required.