Development of an Indirect Stereolithography Technology for Scaffold Fabrication with a Wide Range of Biomaterial Selectivity

Abstract

Tissue engineering, which is the study of generating biological substitutes to restore or replace tissues or organs, has the potential to meet current needs for organ transplantation and medical interventions. Various approaches have been attempted to apply three-dimensional (3D) solid freeform fabrication technologies to tissue engineering for scaffold fabrication. Among these, the stereolithography (SL) technology not only has the highest resolution, but also offers quick fabrication. However, a lack of suitable biomaterials is a barrier to applying the SL technology to tissue engineering. In this study, an indirect SL method that combines the SL technology and a sacrificial molding process was developed to address this challenge. A sacrificial mold with an inverse porous shape was fabricated from an alkali-soluble photopolymer by the SL technology. A sacrificial molding process was then developed for scaffold construction using a variety of biomaterials. The results indicated a wide range of biomaterial selectivity and a high resolution. Achievable minimum pore and strut sizes were as large as 50 and 65 mm, respectively. This technology can also be used to fabricate three-dimensional organ shapes, and combined with traditional fabrication methods to construct a new type of scaffold with a dual-pore size. Cytotoxicity tests, as well as nuclear magnetic resonance and gel permeation chromatography analyses, showed that this technology has great potential for tissue engineering applications.

Porogen Templating Processes: An Overview

“…In their process, the porogen templates were made of wax or other dissolvable thermoplastic materials by inkjet printing, and then used as an inverse mold for injection molding of polymer solution or melt. Similar processes have also been investigated by others [18][19][20][21]. These previous studies have been primarily focused on fabrication of biomédical scaffolds with well-defined porous stmctures.…”

“…Nevertheless, most resins used in SLA after curing cannot be easily removed by solvent extraction or other processes. To this end, Kang and Cho [18] recently applied an alkali-soluble photopolymer with a formulation previously developed by Liska et al [45] to SLA and used the resulting porogen template as a sacrificial mold for molding a variety of biomaterials including PLGA, PLLA, PCL, alginate, chitosan, and bone cement. Compared to conventional SFTF processes including SLA, ^-SLA can be orders of magnitude slower, and therefore applications to parts with large overall sizes must be justified by the overwhelming demand for high resolution.…”

Repairing rabbit radial defects by combining bone marrow stroma stem cells with bone scaffold material comprising a core-cladding structure

“…Bone tissue engineering primarily consists of three major factors. The bone scaffold material is the most critical factor in bone tissue engineering because it serves as a carrier of seed cells and active factors, and provides support for the formation of new bones (Kang and Cho, 2012;Paşcu et al, 2013). Proper structure, appropriate physical properties, and excellent biocompatibility are the most important requirements of an ideal bone scaffold material.…”

Comparison and analysis of different 3d printing techniques

“…Acrylic and epoxy resin polymer materials are commonly used in SLA technique. The cost of photo-curable resin materials are ranging from 80 dollars to 210 dollars per liter, which is a main barrier for implementing this technique [13]. The working principle of stereolithography (SLA) is shown in fig. 1 Figure 1 The Working Principle Of Stereolithography SLA…”