Solvent casting-particulate leaching method

In later work, PEO and PCL PUs were blended by simple mixing to form three-dimensional sponges using solvent cast/particulate leaching methods. 

In the second cases porous scaffolds were prepared by the solvent/casting particulate leaching method using DCM as a solvent and NaCl as porogen. After evaporation of the solvent the polymer with porogen was placed in distilled water and left to completely remove the porogen. 

Solvent-casting, particulate-leaching is a common method of creating porous foams. 

In addition to the chemical properties of the material, physical properties such as surface area for cell attachment are essential. Various methods of creating pores in these materials to increase sirrface area are used. Scaffolds formed using the different techniques, which include fiber bonding, solvent casting/particulate leaching, gas foaming and phase separation are known, which result in different porosity, pore size, and the promotion of tissue growth [127]. 

Fig. 4a, b. Scanning electron photomicrographs of amorphous poly(L-lactic acid) foams a 92% porosity and 30 pm median pore diameter b and 91% porosity and 94 pm median pore diameter. Prepared by a solvent-casting and particulate-leaching method [32] using 90 wt% sieved sodium chloride particles of size range between 0-53 pm and 106-150 pm, respectively... 

The lack of control over pore size is a major issue for methods such as fiber bonding, but solvent casting and particulate leaching (SC-PL) allows for fine control over pore... 

Solvent casting and particulate leaching (SC/PL) is a simple and commonly used method for fabricating scaffolds for tissue engineering. With an appropriate thermal treatment, porous constructs of synthetic biodegradable polymers can be prepared with specific porosity, surfaceivolume ratio, pore size and crystallinity for different applications. This method involves mixing water-soluble salt (e.g. sodium chloride, sodium citrate) particles into a polymer solution. The mixture is then cast into the mould of the desired shape. After the solvent is removed by evaporation or lyophilization, the salt particles are leached out to obtain a porous structure with the pore shape limited to the cubic crystal shape of the salt. Removal of soluble particles from the interior of a polymer matrix is difficult and limits the thickness of the films prepared to ca. 2 mm [293]. 

---