Temperature-driven processing techniques for manufacturing fully interconnected porous scaffolds in bone tissue engineering

Abstract

The development of structures with a predefined multiscale pore network is a major challenge in designing tissue engineering (TE) scaffolds. To address this, several strategies have been investigated to provide biocompatible, biodegradable porous materials that would be suitable for use as scaffolds, and able to guide and facilitate the cell activity involved in the generation of new tissue regeneration. This study seeks to provide an overview of different temperature-driven process technologies for developing scaffolds with tailored porosity, in which pore size distribution is strictly defined and pores are fully interconnected. Here, three-dimensional (3D) porous composite scaffolds based on poly(epsilon-caprolactone) (PCL) were fabricated by thermally induced phase separation (TIPS) and by melt co-continuous polymer blending (MCPB). The combination of these processes with a salt leaching technique enables the establishment of bimodal porosity within the polymer network. This feature may be exploited in the development of substrates with fully interconnected pores, which can be used effectively for tissue regeneration. Various combinations of the proposed techniques provide a range of procedures for the preparation of porous scaffolds with an appropriate combination of morphological and mechanical properties to reproduce the requisite features of the extracellular matrix (ECM) of hard tissues such as bone.

Biodegradable Microparticles and Nanoparticles by Electrospraying Techniques

“…These features make this polymer an ideal biocompatible material for several applications including drugdelivery systems and tissue graft substitutes (18). In the past, the application of PCL in drug delivery was limited because its degradation and resorption kinetics are considerably slower than those of other aliphatic polyesters, due to its hydrophobic character and high crystallinity, thus directing it by preference to use for hard tissue regeneration (19,20). More recently, PCL has been successfully used in the preparation of longterm implantable devices loaded with anticancer drugs (e.g., tamoxifen).…”

Bio-safe processing of polylactic-co-caprolactone and polylactic acid blends to fabricate fibrous porous scaffolds for in vitro mesenchymal stem cells adhesion and proliferation

“…TIPS represents one of the most versatile techniques suitable to prepare porous scaffolds composed of polymeric fibers with 100-500 nm size range [11,25,38]. Indeed, TIPS can be applied to a large variety of synthetic and natural polymers, whereas fibers morphology and density can be adjusted by simply changing the polymeric solution composition and the thermal history [25,38].…”

“…Indeed, TIPS can be applied to a large variety of synthetic and natural polymers, whereas fibers morphology and density can be adjusted by simply changing the polymeric solution composition and the thermal history [25,38].…”

Application of 3D printing technology in bone tissue engineering

“…Numerous conventional techniques including solvent casting with particulate leaching, fiber bonding, membrane lamination, freeze drying, and gas foaming were developed to fabricate porous scaffolds [33,34]. Although these techniques applicable to the preparation of porous scaffolds, but incapable of precisely controlling pore size, geometry and pore interconnectivity, the appearance is also unable to fully fit the defected bone tissues and therefore cannot be adapted to fabricate personalized scaffolds [35].…”