| The small leucine-rich proteoglycans (SLRP), prevalent in collagenous tissues, regulate collagen fibrillogenesis and provide a host of biochemical cues critical to tissue function and homeostasis. Tissue engineering designs to mimic the native extracellular matrix (ECM) may be enhanced by incorporating SLRPs; however, SLRPs must be purified from animal sources bearing low yields and lack of design control. Consequently, synthetic peptidoglycans, inspired by the native SLRP decorin, have been designed. The synthetic peptidoglycans contain a collagen-binding peptide attached to a glycosaminoglycan (GAG) and can be engineered with respect to the peptide sequence, number of attached peptides, and GAG identity, providing unique design control. The influence of peptidoglycans on collagen fibrillogenesis, fibril morphology, and viscoelastic properties of collagen gels are assessed. Peptidoglycans act similarly to the native SLRP decorin as they delay fibrillogenesis and decrease characteristic D-banded fibril diameter by inhibiting lateral aggregation of collagen monomer during fibril formation. In addition, the viscoelastic properties of collagen gels are enhanced by varying degrees when incorporating peptidoglycans. Application for tissue engineering is demonstrated as peptidoglycans are incorporated into collagen gels seeded with smooth muscle cells. This tailorable peptidoglycan design is expected to have versatile application in tissue engineering. |
