3D Printing of Bone-Mimetic Scaffold Composed of Gelatin/ß-Tri-Calcium Phosphate for Bone Tissue Engineering.

3D printed scaffolds composed of gelatin and ß-tri-calcium phosphate (ß-TCP) as a biomimetic bone material are fabricated, thereby providing an environment appropriate for bone regeneration. The Ca2+ in ß-TCP and COO- in gelatin form a stable electrostatic interaction, and the composite scaffold shows suitable rheological properties for bioprinting. The gelatin/ß-TCP scaffold is crosslinked with glutaraldehyde vapor and unreacted aldehyde groups which can cause toxicity to cells is removed by a glycine washing. The stable binding of the hydrogel is revealed as a result of FTIR and degradation rate. It is confirmed that the composite scaffold has compressive strength similar to that of cancellous bone and 60 wt% ß-TCP groups containing 40 wt% gelatin have good cellular activity with preosteoblasts. Also, in the animal experiments, the gelatin/ß-TCP scaffold confirms to induce bone formation without any inflammatory responses. This study suggests that these fabricated scaffolds can serve as a potential bone substitute for bone regeneration.

Effect of different particles on cell proliferation in polymer scaffolds using a solvent-casting and particulate leaching technique.

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 degrees C). Cultured chondrocytes (from knee cartilage) and smooth muscle cells (from bladder) were seeded on each scaffolds (5 x 10(6)/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.