Potential of Hydrogels Based on Poly(Ethylene Glycol) and Sebacic Acid as Orthopedic Tissue Engineering Scaffolds

Abstract

In this study, the bioactive effects of poly(ethylene glycol) (PEG) sebacic acid diacrylate (PEGSDA) hydrogels with or without RGD peptide modification on osteogenic differentiation and mineralization of marrow stromal cells (MSCs) were examined. In a separate experiment, the ability of PEGSDA hydrogel to serve as a delivery vehicle for bone morphogenetic protein 2 (BMP-2) was also investigated. As a scaffold, the attachment and proliferation of MSCs on PEGSDA hydrogel scaffolds with and without RGD peptide modification was similar to the control, tissue culture polystyrene. In contrast, cells were barely seen on unmodified PEG diacrylate (PEGDA) hydrogel throughout the culture period for up to 21 days. Osteogenic phenotypic expression such as alkaline phosphatase (ALP) of MSCs as well as mineralized calcium content were significantly higher on PEGSDA-based hydrogels than those on the control or PEGDA hydrogels. Potential use of PEGSDA scaffold as a delivery vehicle of osteogenic molecules such as BMP-2 was also evaluated. Initial burst release of BMP-2 from PEGSDA hydrogel scaffold (14.7%) was significantly reduced compared to PEGDA hydrogel scaffold (84.2%) during the first 3 days of a 21-day release period. ALP activity of an osteoblast was significantly higher in the presence of BMP-2 released from PEGSDA hydrogel scaffolds compared to that in the presence of BMP-2 released from PEGDA scaffolds, especially after 6 days of release. Overall, PEGSDA hydrogel scaffolds without further modification may be useful as orthopedic tissue engineering scaffolds as well as local drug carriers for prolonged sustained release of osteoinductive molecules.

Evaluation of Multifunctional Polysaccharide Hydrogels with Varying Stiffness for Bone Tissue Engineering

“…Despite these advantages, the use of hydrogels is associated with a number of limitations. This includes a limited ability to induce mineralization, 8,9 potential for bacterial infection, 2,10 dissimilarity to host tissue (together with poor cell proliferation and attachment), 11 and a low mechanical modulus to support tissue regeneration. 12,13 Another major impediment for using hydrogels in bone tissue engineering is poor or nonexistent growth and proliferation of endothelial cells in the newly forming tissue, 14 which potentially can lead to delayed delivery of nutrients to mineralized bone and its cellular constituents.…”

Improved intervention of atherosclerosis and cardiac hypertrophy through biodegradable polymer-encapsulated delivery of glycosphingolipid inhibitor

“…To overcome these impediments, in this study we examined whether using an order of magnitude lower dose of polymer-encapsulated D-PDMP interferes with GSL biosynthesis with sufficient efficacy to reverse pre-existing atherosclerosis and whether this approach could be extended to treat cardiac hypertrophy in vivo . To accomplish these goals we successfully exploited the versatile ability of SA-PEG polymers, which have been used for the controlled release of the cancer drug etoposide [32], carbohydrate-based drug candidates [14], and growth factors [33] to encapsulate the glycosyltransferase inhibitor D-PDMP (Fig. 1).…”

Hybrid collagen-based hydrogels with embedded montmorillonite nanoparticles

“…The isopropyl group [-CH (CH 3 )] of poly(Nisopropylacrylamide) absorption band appears at 1388 cm −1 . On top of that, the crosslinking and polymeric network formation were evidenced by the presence of absorption band at 1731 cm −1 , attributed to C_O functional group of the crosslinker agent [28].…”