3D Bioplotter Research Papers

Three-dimensional (3D) printed hydrogel scaffolds enhanced with ceramics have shown potential applications for cartilage regeneration, but leaving biological and mechanical properties to be desired. This paper presents our study on the development of chitosan /alginate scaffolds with nano hydroxyapatite (nHA) by combining 3D printing and impregnating techniques, forming a hybrid, yet novel, structure of scaffolds for potential cartilage regeneration. First, we incorporated nHA into chitosan scaffold printing and studied the printability by examining the difference between the printed scaffolds and their designs. Then, we impregnated alginate with nHA into the printed chitosan scaffolds to forming a hybrid structure of scaffolds;…

Researchers have looked to cartilage tissue engineering to address the lack of cartilage regenerative capability related to cartilage disease/trauma. For this, a promising approach is extrusion-based three-dimensional (3D) printing technique to deliver cells, biomaterials, and growth factors within a scaffold to the injured site. This paper evaluates the printability of chitosan scaffolds for a cartilage tissue engineering, with a focus on identifying the influence of drying technique implemented before crosslinking on the improvement of chitosan printability. First, the printability of chitosan with concentrations of 8%, 10%, and 12% (w/v) was evaluated and 10% chitosan was selected for further studies. Then,…

Extrusion-based bioprinting of hydrogel scaffolds is challenging due to printing-related issues, such as the lack of capability to precisely print or deposit hydrogels onto three-dimensional (3D) scaffolds as designed. Printability is an index to measure the difference between the designed and fabricated scaffold in the printing process, which, however, is still under-explored. While studies have been reported on printing hydrogel scaffolds from one or more hydrogels, there is limited knowledge on the printability of hydrogels and their printing processes. This paper presented our study on the printability of 3D printed hydrogel scaffolds, with a focus on identifying the influence of…

Low-concentration hydrogels have favorable properties for many cell functions in tissue engineering but are considerably limited from a scaffold fabrication point of view due to poor three-dimensional (3D) printability. Here, we developed an indirect-bioprinting process for alginate scaffolds and characterized the potential of these scaffolds for nerve tissue engineering applications. The indirect-bioprinting process involves (1) printing a sacrificial framework from gelatin, (2) impregnating the framework with low-concentration alginate, and (3) removing the gelatin framework by an incubation process, thus forming low-concentration alginate scaffolds. The scaffolds were characterized by compression testing, swelling, degradation, and morphological and biological assessment of incorporated or…

Peripheral nerve tissue requires appropriate biochemical and physical cues to guide the regeneration process after injury. Bioprinted peptide-conjugated sodium alginate (PCSA) scaffolds have the potential to provide physical and biochemical cues simultaneously. Such scaffolds need characterisation in terms of printability, mechanical stability, and biological performance to refine and improve application in nerve tissue regeneration. In this study, it was hypothesized that 3D scaffold printed with low concentrated multiple PCSA precursor would be supportive for axon outgrowth. Therefore, a 2% (w/v) alginate precursor was conjugated with either arginine-glycine-aspartate (RGD) or tyrosine-isoleucine-glycine-serine-arginine (YIGSR) peptides, or a mixture of RGD and YIGSR (1:2)…

Three-dimensional (3D) bioplotting has been widely used to print hydrogel scaffolds for tissue engineering applications. One issue involved in 3D bioplotting is to achieve the scaffold structure with the desired mechanical properties. To overcome this issue, various numerical methods have been developed to predict the mechanical properties of scaffolds, but limited by the imperfect representation of one key feature of scaffolds fabricated by 3D bioplotting, i.e., the penetration or fusion of strands in one layer into the previous layer. This paper presents our study on the development of a novel numerical model to predict the elastic modulus (one important index…

Tissue scaffolds fabricated by three-dimensional (3D) bioprinting are attracting considerable attention for tissue engineering applications. Because the mechanical properties of hydrogel scaffolds should match the damaged tissue, changing various parameters during 3D bioprinting has been studied to manipulate the mechanical behavior of the resulting scaffolds. Crosslinking scaffolds using a cation solution (such as CaCl2) is also important for regulating the mechanical properties, but has not been well documented in the literature. Here, the effect of varied crosslinking agent volume and crosslinking time on the mechanical behavior of 3D bioplotted alginate scaffolds was evaluated using both experimental and numerical methods. Compression…