title: Investigation of thermal degradation with extrusion-based dispensing modules for 3D bioprinting technology.
abstract: Recently, numerous three-dimensional (3D) bioprinting systems have been introduced for the artificial regeneration of tissues. Among them, the extrusion-based dispensing module is the most widely used because of the processability it gives various biomaterials. The module uses high forces and temperature to dispense materials through a micro-nozzle. Generally, the harsh conditions induce thermal degradation of the material in the dispensing procedure. The thermal degradation affects the properties of the materials, and the change of the properties should be carefully controlled, because it severely affects the regeneration of tissues. Therefore, in this research, the relationship between the dispensing module and the thermal degradation of material was investigated. Extrusion-based dispensing modules can be divided into the syringe type (ST) and filament type (FT) based on working principles. We prepared a poly lactic-co-glycolic acid (PLGA) scaffold with the two methods at various time points. Then, the characteristics of the printed scaffolds were assessed by measuring molecular weight (M w), glass transition temperature (T g), in vitro degradation, compressive modulus, and cytocompatibility. The results showed that the PLGA scaffold with the FT dispensing module maintained its properties regardless of printing time points. In contrast, severe thermal degradation was observed in the scaffold group prepared by the ST dispensing module. Consequentially, it was obvious that the FT dispensing module was more suitable for producing scaffolds without severe thermal degradation.
authors: Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), San 31, Hyoja-dong, Nam-gu, Pohang, Gyungbuk 790-784, Korea.
authors: Hyungseok
authors: H
authors: Lee
authors: James J
authors: JJ
authors: Yoo
authors: Hyun-Wook
authors: HW
authors: Kang
authors: Dong-Woo
authors: DW
authors: Cho
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D019245:Compressive Strength; D004867:Equipment Design; D004868:Equipment Failure; D019544:Equipment Failure Analysis; D019344:Lactic Acid / Q000737:chemistry*; D008422:Materials Testing; D008970:Molecular Weight; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D066330:Printing, Three-Dimensional / Q000295:instrumentation*; D013696:Temperature; D013814:Thermal Conductivity; D023822:Tissue Engineering / Q000295:instrumentation*; D054457:Tissue Scaffolds; D044366:Transition Temperature
chemical_list: D001672:Biocompatible Materials; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid