Study of Physical and Degradation Properties of 3D-Printed Biodegradable, Photocurable Copolymers, PGSA-co-PEGDA and PGSA-co-PCLDA

Abstract

As acrylated polymers become more widely used in additive manufacturing, their potential applications toward biomedicine also raise the demand for biodegradable, photocurable polymeric materials. Polycaprolactone diacrylate (PCLDA) and poly(ethylene glycol) diacrylate (PEGDA) are two popular choices of materials for stereolithography (SLA) and digital light processing additive manufacturing (DLP-AM), and have been applied to many biomedical related research. However, both materials are known to degrade at a relatively low rate in vivo, limiting their applications in biomedical engineering. In this work, biodegradable, photocurable copolymers are introduced by copolymerizing PCLDA and/or PEGDA with poly(glycerol sebacate) acrylate (PGSA) to form a network polymer. Two main factors are discussed: the effect of degree of acrylation in PGSA and the weight ratio between the prepolymers toward the mechanical and degradation properties. It is found that by blending prepolymers with various degree of acrylation and at various weight ratios, the viscosity of the prepolymers remains stable, and are even more 3D printable than pure substances. The formation of various copolymers yielded a database with selectable Young’s moduli between 0.67–10.54 MPa, and the overall degradation rate was significantly higher than pure substance. In addition, it is shown that copolymers fabricated by DLP-AM fabrication presents higher mechanical strength than those fabricated via direct UV exposure. With the tunable mechanical and degradation properties, the photocurable, biodegradable copolymers are expected to enable a wider application of additive manufacturing toward tissue engineering.

Poly(Glycerol Sebacate) in Biomedical Applications—A Review of the Recent Literature

“…However, this could lead in some polymers to physical entanglements and chain extension when cross‐linked via radical polymerization, limiting their applications in further processing steps. [ 62 ]…”

Recent Advances in Regenerative Tissue Fabrication: Tools, Materials, and Microenvironment in Hierarchical Aspects

“…[ 162,163 ] PEGDA has a low in vivo biodegradability, so a copolymer of PEGDA with poly(glycerol sebacate) acrylate (PGA) increases the degradation rate significantly compared with PEGDA without any modification. [ 164 ] PCL has an essential structure for bone tissue engineering and has good biocompatibility and nontoxicity for medical implant purposes. [ 138,165 ] The good mechanical properties (high strength) and the large biodegradation rate of PCL allow its use for bone fabrication in tissue engineering (Figure 5A).…”

Review of Polymeric Materials in 4D Printing Biomedical Applications

“…The main characteristic of 4D printing lies in the shape-shifting capabilities of a 3D printed static object. Shape variations in 4D printed objects can be induced by different external stimuli to cause programmed shrinkage, expansion or folding of the printed objects [7,8]. The main difference between 3D and 4D printing lies in the shape changing material (SCM) used, which is the advanced material that exhibits specific changes in response to external conditions.…”