Fabrication and characterization of 3D scaffold using 3D plotting system

Abstract

In this paper, we design and fabricate a 3D scaffold using rapid prototyping (RP) technology for tissue engineering. The scaffold should have a three-dimensional interconnected pore network. We fabricate a polycaprolactone (PCL) scaffold with interconnecting pores and uniform porosity for cell ingrowth using a 3D plotting system. In order to keep the three dimensional shape under mechanical loading while implanted, we design an oscillating nozzle system to increase elastic modulus and yield strength of PCL strand. We characterize the influence of pore geometry, compressive modulus of the scaffold, elastic modulus and yield strength of the strand using SEM, dynamical mechanical analysis (DMA) and Nano-UTM. Finally the cell responses on scaffolds are observed. 3D scaffold, polycaprolatone (PCL), rapid prototyping (RP), oscillating nozzle, tissue engineeringCitation: Lee J-H, Park S-A, Park K E, et al. Fabrication and characterization of 3D scaffold using 3D plotting system. Chinese Sci Bull, 2010, 55: 94-98, A 3D scaffold for tissue regeneration is a supporting structure to hold cells in place. It should have a three-dimensional interconnected pore network for cell growth, nutrient delivery, and metabolic waste. And it also needs good mechanical properties to keep the three-dimensional shape under mechanical loading while implanted [1,2]. Conventional scaffold fabrication methods include solvent casting and particle leaching [3], gas foaming [4], melt molding [5], fiber meshes and fiber bonding [6,7], phase separation [8], and freeze drying [9,10]. But there are several limitations to the conventional scaffold fabrication methods. These methods cannot precisely control pore size, interconnection of pores, or pore geometry.In order to overcome these limitations, a rapid prototyping (RP) system has been proposed to solve these problems [1,2]. The RP system can control the pore size, pore geometry, and interconnection of pores in the scaffold. The scaffold fabricated by a RP system has a three-dimensional interconnected pore network, so it can transport more oxygen and nutrients deep into the scaffold. Metabolic waste can be easily transported within the interconnected pore network. There are a lot of methods for the fabrication of the RP scaffold, such as selective laser sintering (SLS) [11], fused deposition modeling (FDM) [12], stereolithography (SLA) [13], 3D printing [14] and 3D plotting [15]. As the 3D scaffold is a supporting structure, the mechanical properties of the scaffold are of great importance, especially for the field of bone tissue engineering. Some of the work has been done to analyze the mechanical properties of the 3D scaffold made by particle leaching method [16][17][18]. However, few studies have been done to characterize and improve the mechanical properties of the 3D scaffold made by an RP system.In this paper, we design and fabricate a 3D PCL scaffold using a PR system-3D plotter. In order to increase the elastic modulus and yield strength of the PCL strands in the

Fabrication of porous polycaprolactone/hydroxyapatite (PCL/HA) blend scaffolds using a 3D plotting system for bone tissue engineering

“…This study investigated the structural properties of hydroxyapatite scaffold for bone substitute replacement. We studied about the structural properties of the plotted scaffold compared to conventional fabrication, such as salt leaching in a previous study [22]. We found that the plotted scaffold had more open and interconnected pore structures to induce cell ingrowth within the scaffold than a salt leached scaffold.…”

Assessments for bone regeneration using the polycaprolactone SLUP (salt‐leaching using powder) scaffold

“…In this study, the in vitro and in vivo characteristics of SLUP, conventional salt‐leaching and 3D‐plotted scaffolds were characterized. The 3D‐plotted scaffold, which is a SFF scaffold, has excellent biological behavior compared with the salt‐leaching scaffold due to its increased pore interconnectivity because of its well‐defined geometry . Moreover, the 3D‐plotted scaffold was fabricated with a 500‐μm strand size and 1000‐μm distances between strands.…”

“…6, 8, 10(b) and 6, 8, 10(c)). The SLUP scaffold groups were compared with recently reported studies . Lee et al, Park et al, and Sun et al showed that even if the porosity of salt‐leaching scaffolds were higher than those of 3D‐plotted scaffolds, cell ingrowth rates on the salt‐leaching scaffolds were lower than those on the 3D‐plotted scaffolds due to the poorer pore interconnectivity of the salt‐leaching scaffold.…”

“…Lee et al, Park et al, and Sun et al showed that even if the porosity of salt‐leaching scaffolds were higher than those of 3D‐plotted scaffolds, cell ingrowth rates on the salt‐leaching scaffolds were lower than those on the 3D‐plotted scaffolds due to the poorer pore interconnectivity of the salt‐leaching scaffold. In other words, seeded cells proliferated only on the surfaces of the salt‐leaching scaffold without the observed ingrowth of the 3D‐plotted scaffolds . Lee et al also reported that new bone formations on MSTL scaffolds with relatively lower porosity (prepared via SFF methods) were better than those on GF/PL scaffolds with relatively higher porosity because the pore interconnectivity was better in the MSTL scaffolds .…”

Rapid Prototyping Assisted Scaffold Fabrication for Bone Tissue Regeneration

“…After 8weeks of incubation it was observed that chondrocytes started filling up the interconnected pores and were fully spread on the 3D plotted scaffold surface. It was concluded that 3D plotted scaffold supports the speedy tissue formation with cell attachment in short time (Hee et al, 2010). Demonstration of different cell sources that are currently used in bone tissue regeneration is shown on Table 2.…”