Solvent-casting and particulate leaching are widely used in the manufacturing of porous polymer scaffolds. Salt is the most commonly used particulate because it is easily available and very easy to handle. Gelatin particles are another candidate for this method because they are known as a material that enhances cell attachment and proliferation. In this study, we compared the biocompatibility of the two scaffolds made from either salt (salt scaffold) or gelatin particles (gelatin scaffold). Sieved particles of salt and gelatin (particle size ranging 100–180 um) were dispersed in a poly-lactic-co-glycolic acid (PLGA)/chloroform solution and cast in a Teflon container. The solvent was allowed to evaporate and residual amounts were removed by vacuum drying. The particles were allowed to leach out by immersion in warm water (40°C). Cultured chondrocytes (from knee cartilage) and smooth muscle cells (from bladder) were seeded on each scaffolds (5 × 106/cm2) and cultured for 3 weeks, and their proliferation was compared using hematoxylin and eosin staining. These results demonstrated that the gelatin scaffold showed better attachment of cells at the initial stage, and both cell types showed much better proliferation of cells during 3 months. The better performance of a gelatin scaffold also contributed to the better connection of pores at the same porosity.
1. Solvent casting
Solvent-casting and particulate-leaching techniques involve using a polymer
solution uniformly mixed with salt particles of a specific diameter. The solvent then
evaporates leaving behind a polymer matrix with salt particles embedded
throughout. The composite is immersed in water, where the salt leaches out to
produce a porous structure. Highly porous scaffolds with porosity values up to 93%
and average pore diameters up to 500 μm can be formed using this technique. A
disadvantage of this technique is that it can only be used to produce thin membranes
up to 3 mm thick.