Provided herein is a method of forming medical device that includes RGD attached to the device via a spacer compound. The method comprises providing a spacer compound comprising a hydrophobic moiety and a hydrophilic moiety, grafting or embedding the spacer compound to the surface layer of the polymer to cause the hydrophobic moiety to be grafted to or embedded within the surface layer of polymer, and attaching a chemo-attractant to the hydrophilic moiety.