M. Kantlehner et al., Surface coating with cyclic RGD peptides stimulates osteoblast adhesion and proliferation as well as bone formation, CHEMBIOCHEM, 1(2), 2000, pp. 107-114
The physiological inertness of synthetic implant materials often results in
insufficient implant integration and limited acceptance of implants in tis
sues. After implantation the implant surface is often separated from the su
rrounding healthy and regenerating tissues, for example by a fibrous capsul
e. To avoid this host-versus-graft reaction, a strong mechanical contact be
tween tissue and implant must be ensured. An enhance contact between graft
and the surrounding tissue can be provided by coating the implant with cell
-adhesive molecules. The highly active and alpha (nu)beta (3)- and alpha (n
u)beta (5)- integrin-selective peptide c(-RGDfk-) (f = D- phenylalanine) wa
s functionalized with various linker molecules containing an acrylamide end
group by using the lysine side chain of c(-RGDfk-). The acrylamide group c
an be used to bind the peptide covalently to poly(methyl methacrylate) (PMM
A) surfaces. The coated surfaces effectively bind to murine osteoblasts as
well as human osteoblasts in vitro when a minimum distance of 3.5 nm betwee
n surface and the constrained RGD sequence is provided. In contrast to oste
oblasts in cell suspension, surface-bound osteoblasts show no apoptosis but
proliferate by a factor of 10 over a 22 d period. Coating of inert implant
surfaces with highly active and alpha (nu)-selective peptides affords a ma
rked improvement in osteoblast binding over current technologies. In vivo s
tudies show that peptide-coated PMMA pellets implanted into the patella gro
ove of rabbits are integrated into the regenerating bone tissue faster and
more strongly than uncoated pellets.