Editing Tissue engineering (section)

====Solvent casting and particulate leaching====
[[Solvent casting and particulate leaching]] (SCPL) allows for the preparation of structures with regular porosity, but with limited thickness. First, the polymer is dissolved into a suitable organic solvent (e.g. [[polylactic acid]] could be dissolved into [[dichloromethane]]), then the solution is cast into a mold filled with porogen particles. Such porogen can be an inorganic salt like [[sodium chloride]], crystals of [[saccharose]], [[gelatin]] spheres or [[Paraffin wax|paraffin]] spheres. The size of the porogen particles will affect the size of the scaffold pores, while the polymer to porogen ratio is directly correlated to the amount of porosity of the final structure. After the polymer solution has been cast the solvent is allowed to fully evaporate, then the composite structure in the mold is immersed in a bath of a liquid suitable for dissolving the porogen: water in the case of sodium chloride, saccharose and gelatin or an [[aliphatic]] solvent like [[hexane]] for use with paraffin. Once the porogen has been fully dissolved, a porous structure is obtained. Other than the small thickness range that can be obtained, another drawback of SCPL lies in its use of organic solvents which must be fully removed to avoid any possible damage to the cells seeded on the scaffold.