Effect of RGD coating on osteocompatibility of PLGA-polymer disks in a rat tibial wound

Abstract

Osteocompatibility of porous polylactic-glycolic acid (PLGA) disks coated with synthetic peptides was assessed in 5-mm diameter unicortical tibial osseous wounds in rats. The coatings consisted of various ratios of peptides including the tripeptide arginine-glycine-aspartic acid (RGD) and the inactive arginine-glycine-glutamic acid (RGE). When left empty, the tibial wounds healed spontaneously with proliferation of intramedullary woven bone within 1 week. The reactive bone was resorbed, and by 3 weeks, the cortical wound was healed with lamellar bone, and the medullary space was repopulated with marrow. When PLGA disks were implanted there was a delay in repair with reduced bone fill and no bone bridging at 3 weeks. When disks were coated with increasing amounts of RGD peptide, there was a biphasic effect on osteocompatibility and on osseous ingrowth. Evaluation at 10 days showed a dose-dependent increase, with 1.5-fold greater osteocompatibility (p < 0.05) and 1.6-fold more osseous ingrowth into the polymer (p < 0.01) than uncoated disks. With more RGD and with undiluted RGE, osteocompatibility and osseous ingrowth were the same as with uncoated disks. At 3 weeks, there were no significant differences among all the groups. These data indicate that RGD coating enhanced early stages of osteocompatibility and ingrowth.

Structure and function of RGD peptides involved in bone biology

“…Surface modification of polylactid films and structures with linear RGD peptides support bone marrow cell growth, differentiation and mineralization [101]. A healing wound model provided information about the positive influence of osteocompatibility and the negative inflammatory potential of a linear RGD peptide [102]. Our group developed a system to functionalize polymethylemethacrylate with cyclic RGD peptides.…”

Multifunctional Polymeric Nanostructures for Therapy and Diagnosis

“…Quantum dots (QDs) and polyrotaxanes (PRs) are two types of nanomaterials whose hybridization should, we hope, lead to nanostructures with these characteristics. One of the most important products of QDs in nanomedicine over current techniques is their ability to track cells in vivo easily and without the need to sacrifice animals [290][291][292].…”

Next Generation of Electrosprayed Fibers for Tissue Regeneration

“…Although a number of other materials generated using polymer chemistry, synthetic polymers do not possess a surface chemistry that is familiar to cells. Despite significant efforts to improve these limitations via co-polymerization 71 and grafting Arg-Gly-Asp peptides (necessary for cell adhesion), 72,73 recreating all the biological responses needs significant investigation.…”

“…Although a number of other materials generated using polymer chemistry, synthetic polymers do not possess a surface chemistry that is familiar to cells. Despite significant efforts to improve these limitations via co-polymerization 71 and grafting Arg-Gly-Asp peptides (necessary for cell adhesion), 72,73 recreating all the biological responses needs significant investigation.On the contrary, ECM components play a significant role in tissue remodeling under pathological conditions, and their role in diverse molecular mechanisms has been extensively studied in clinical samples. 74,75 However, the problem in using natural polymers is processing into different forms without chemical modifications.…”