Characterization of Photo-Cross-Linked Oligo[poly(ethylene glycol) fumarate] Hydrogels for Cartilage Tissue Engineering

Abstract

Photo-cross-linkable oligo[poly(ethylene glycol) fumarate] (OPF) hydrogels have been developed for use in tissue engineering applications. We demonstrated that compressive modulus of these hydrogels increased with increasing polymer concentration, and hydrogels with different mechanical properties were formed by altering the ratio of cross-linker/polymer in precursor solution. Conversely, swelling of hydrogels decreased with increasing polymer concentration and cross-linker/polymer ratio. These hydrogels are degradable and degradation rates vary with the change in cross-linking level. Chondrocyte attachment was quantified as a method for evaluating adhesion of cells to the hydrogels. These data revealed that cross-linking density affects cell behavior on the hydrogel surfaces. Cell attachment was greater on the samples with increased cross-linking density. Chondrocytes on these samples exhibited spread morphology with distinct actin stress fibers, whereas they maintained their rounded morphology on the samples with lower cross-linking density. Moreover, chondrocytes were photoencapsulated within various hydrogel networks. Our results revealed that cells encapsulated within 2-mm thick OPF hydrogel disks remained viable throughout the 3-week culture period, with no difference in viability across the thickness of hydrogels. Photoencapsulated chondrocytes expressed the mRNA of type II collagen and produced cartilaginous matrix within the hydrogel constructs after three weeks. These findings suggest that photo-cross-linkable OPF hydrogels may be useful for cartilage tissue engineering and cell delivery applications.

Peripheral Nerve Grafts and Chondroitinase ABC Application Improves Functional Recovery After Complete Spinal Cord Transection

“…The release profile can be tailored by changing the molecular weight of the polyethylene glycol, which changes the amount of crosslinking in the hydrogel [27].…”

Sustained Delivery of Dibutyryl Cyclic Adenosine Monophosphate to the Transected Spinal Cord Via Oligo [(Polyethylene Glycol) Fumarate] Hydrogels

“…22,23 The molecular weight of the poly(ethylene glycol) used in macromer formation controls the mechanical and degradation properties of the OPF hydrogels. 23,24 Potential applications of these hydrogels include bone tissue engineering, [24][25][26][27] scaffold material for marrow stromal cell attachment and differentiation, [28][29][30][31] cell encapsulation, 30,31 cartilage tissue engineering, 32 and the controlled release of various compounds. [33][34][35] Recent studies suggest applications in the nervous system using positively charged hydrogels.…”

Designing 3D Photopolymer Hydrogels to Regulate Biomechanical Cues and Tissue Growth for Cartilage Tissue Engineering

“…As such, photopolymerized hydrogels have been used as cell carriers for a number of tissue engineering applications including cartilage (14)(15)(16)(17)(18), bone (19)(20)(21), nerve (22), liver (23), and more recently for maintaining undifferentiated human embryonic stem cells in long term 3D cultures (24). Our research group is particularly interested in exploiting the gel architecture and chemistry of photopolymerized hydrogels to promote functional tissue growth for cartilage tissue engineering.…”