Design and fabrication of 3D‐plotted polymeric scaffolds in functional tissue engineering

Abstract

Regenerating the load‐bearing tissues requires 3D scaffolds that balance the temporary mechanical function with the biological requirements. In functional tissue engineering, designing scaffolds with biomimetic mechanical properties could promote tissue ingrowth since the cells are sensitive to their local mechanical environment. This work aims to design scaffolds that mimic the mechanical response of the biological tissues under physiological loading conditions. Poly(L‐lactide) (PLLA) scaffolds with varying porosities and pore sizes were made by the 3D‐plotting technique. The scaffolds were tested under unconfined ramp compression to compare their stress profile under load with that of bovine cartilage. A comparison between the material parameters estimated for the scaffolds and for the bovine cartilage based on the biphasic theory enabled the definition of an optimum window for the porosity and pore size of these constructs. Moreover, the finite element prediction for the stress distribution inside the scaffolds, surrounded by the host cartilaginous tissue, demonstrated a negligible perturbation of the stress field at the site of implantation. The finite element modeling tools in combination with the developed methodology for optimal porosity/pore size determination can be used to improve the design of biomimetic scaffolds. POLYM. ENG. SCI., 47:608–618, 2007. © 2007 Society of Plastics Engineers.

Physical and biological characteristics of nanohydroxyapatite and bioactive glasses used for bone tissue engineering

“…Additive manufacturing (AM) technologies have shown promise in developing scaffolds with rigorously controlled internal architectures and mechanical properties for tissue and organ regeneration [172][173][174]. However, viscosity constraint is a stumbling block for the majority of extrusion-based AM techniques [175,176].…”

Direct‐Write Assembly of Microperiodic Silk Fibroin Scaffolds for Tissue Engineering Applications

“…Rapid prototypingbased manufacturing techniques can be used to generate scaffolds having precisely controlled micro-and nanoscale architectures and highly interconnected pores using computer aided design/machining approaches. For example, stereolithography, selective laser sintering, and three-dimensional printing, [13][14][15][16][17][18][19] have been employed to deposit thermoplastic polymers in layer-by-layer approaches that result in 3D fibrous architectures with fiber diameters that range from 150-400 mm. These scaffolds are important in the field of tissue engineering, as they offer enhanced mass transfer of nutrients, oxygen and metabolic wastes due to the interconnected porous architecture compared to conventionally fabricated particle-leached porous scaffolds.…”

“…Importantly, these scaffolds contained feature sizes that were significantly smaller than those produced by other rapid prototyping techniques. [14][15][16][17][18][19] Initial investigations of the use of these direct-write scaffolds on human bone marrow-derived mesenchymal stem cells (hMSCs) was also assessed with a focus on chondrogenic differentiation. The scaffolds supported both cell adhesion and growth as well as enhanced chondrogenic differentiation based on increased glucosaminoglycan production compared to standard pellet culture.…”

Design and Dynamic Culture of 3D-Scaffolds for Cartilage Tissue Engineering

“…Subsequently, each scaffold was punched into discs of 4 mm of diameter and then immersed in water at 50 o C for up to 6 hours to extract the salt particles, air-dried for 24 hours and vacuum-dried for 48 hours to allow complete evaporation of the solvent/water. Determination of the plotting parameters, rheological characterization of the paste, and porosity measurements are based on previously published work [16].…”