Fabrication of poly(lactic acid) scaffolds by a modified solvent casting/porogen leaching method

Abstract

Abstract:A modified solvent casting/particulate leaching (SC/PL) method was developed to fabricate thick three-dimensional poly(lactic acid) (PLA) scaffolds with controlled pore size and porosity, and much shorter processing time. The pasty mixture of PLA/CHCl 3 /NaCl was sealed in a Buchner funnel by a piston with a suction flask connected. A vacuum pump was used to facilitate the volatilization of solvent. The scaffolds were obtained by subsequent removal of NaCl in deionized water. The pore size within the scaffold was in good accordance with the particle size of NaCl (< 210, 210~310, 310~420 and 420~500 μm), all of which had more than 89 % of porosity, 1.95 ± 0.2 MPa of compressive modulus and non-cytotoxic to L929 cells. To demonstrate the applicability of the SC/VV/PL method, thick cylindrical and tubular porous scaffolds have been produced in this study. Compared with the traditional SC/PL without vacuum volatilization, the modified method, namely, solvent casting/vacuum volatilization/particulate leaching (SC/VV/PL) method, provide a more efficient way to fabricate thick scaffolds.

Challenges in the Characterization of Plasma-Processed Three-Dimensional Polymeric Scaffolds for Biomedical Applications

“…In addition, overall morphology and surface topography become important considerations in developing artificial materials that can constructively interact with biological molecules to create biomimetic systems such as with tissue regeneration. Although researchers have developed a host of methods to produce 3D polymeric scaffolds, ,,, significant inconsistencies in the formation process (i.e., each scaffold can have a different morphology and surface topography) can ultimately lead to poor interactions with biological species and/or device failure. For scaffolds produced in the porogen-leaching method employed here, the molding process introduces two morphologically different faces: one that is in contact with the Teflon mold and the other that is in contact with air/ethanol/water during the curing process.…”

“…Recently, researchers have focused on two biodegradable polymeric materials, poly( d , l -lactic acid) (P d , l LA) and poly(ε-caprolactone) (PCL) to create three-dimensional (3D) scaffolds for a range of biomedical applications, most notably tissue engineering. − Although the 3D structure nominally mimics the structural design of the extracellular matrix, it is critical that any 3D construct used in the development of artificial tissues also have the surface properties that provide the appropriate biological responses from proteins, cells, and other biofluids. , One of the major drawbacks to using either P d , l LA or PCL for tissue regeneration is that these polymers are naturally hydrophobic, which tends to inhibit cell adhesion and proliferation. One approach to modifying P d , l LA and PCL is to graft extracellular matrix components such as proteins (e.g., fibronectin) or smaller peptide sequences onto the surface of the polymer scaffold. ,, The presence of such bioactive ligands into the polymer structure can enhance cell adhesion and function.…”