Assessment of cell proliferation in salt‐leaching using powder (SLUP) scaffolds with penetrated macro‐pores

Abstract

In this study, a salt-leaching using powder (SLUP) scaffold with penetrated macropores was proposed to enhance cell proliferation. A SLUP scaffold is a salt-leaching scaffold with an arbitrary pore configuration. Although SLUP scaffolds have several advantage over traditional salt-leaching scaffolds, the cell ingrowth might be poor compared with solid freeform fabrication scaffolds, which have well-interconnected pores. We therefore proposed SLUP scaffolds with penetrated macropores to assist the cell ingrowth. First, polycaprolactone (PCL) powders with a grain size of 63-100 lm and NaCl powders with a grain size of 100-180 lm were prepared. Next, a uniformly perforated mold was fabricated using an rapid prototyping (RP) system. Then, 500-, 820-, or 1200-lmdiameter needles were inserted into the holes of the RP mold. Subsequently, the mold was filled with a mixed powder of PCL/NaCl (30 : 70 vol %). The mold was then heated in the oven at 100 C for 30 min, and both the needles and the mold were removed from the PCL/NaCl mixture. Then, the PCL/NaCl mixture was soaked in DI water for 24 h to leach out NaCl particles and dried in a vacuum desiccator for 24 h. The porosity of fabricated scaffolds was calculated using a simple equation, and the compressive stiffness was measured using a universal testing machine. Moreover, each scaffold (10 3 10 3 10 mm 3 ) was seeded with 100,000 Saos-2 cells and cultured for 14 days. The cell proliferation characteristics were assessed using a CCK-8 assay at 1, 7, and 14 days for comparison with the control scaffolds, that is, the SLUP scaffolds with no penetrated macropores. V C 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40240.

Fabrication of scalable tissue engineering scaffolds with dual-pore microarchitecture by combining 3D printing and particle leaching

“…The random pore scaffolds were fabricated using salt leaching process as described previously [9,12]. 10 g of NaCl was mixed with 1 ml of water on a 100 mm plastic petri plate as described above.…”

“…Therefore, there is a need for a second type of porous structure, which can efficiently interconnects local random pores of the scaffold for better generation of large tissues under in vitro and in vivo conditions. Recently, studies using dual-pore scaffolds, comprising structured pores (channels) in combination with local random porous regions, have shown tremendous potential towards engineering of complex tissues with better cell proliferation due to improved nutrient and oxygen transport [3,[11][12][13][14][15][16]. A recent report also demonstrated that after transplantation of dual-porous scaffolds more cells from the host tissue infiltrated into the scaffolds due to its smart global pore architecture compared to random porous scaffolds, hence, enhancing integration of blood vessels in the host tissue [17].…”

“…Different approaches have been employed to fabricate dual-pore scaffolds for tissue engineering using both natural and synthetic polymers [3,[11][12][13][14][15]18,19]. For controlling the size and degree of porosity of the random pores as well as the mechanical properties of the scaffolds, the two major fabrication techniques have been freeze-drying [3,11,13,14,20] and salt leaching [11,12,16] process.…”

“…For controlling the size and degree of porosity of the random pores as well as the mechanical properties of the scaffolds, the two major fabrication techniques have been freeze-drying [3,11,13,14,20] and salt leaching [11,12,16] process. The published results have shown that freeze-drying cannot yield as large a range of pore dimensions as salt leaching, which can utilize salt crystals of various dimensions depending on the requirements.…”

“…Currently various solid freeform (SFF) fabrication techniques such as stereolithography based printing have been reported to fabricate 3D porous scaffolds with well controlled pore size, porosity and mechanical properties using photo-crosslinkable materials [21,22]. Sacrificial moulds from SFF fabrication [11] or metallic wires [3,12,16,19] have been implemented for the generation of structured pores. Automated SFF fabricated moulds have several advantages compared to metal wire based moulds that require choice of wire dimensions and time consuming manual assembly of a number of wires.…”