title: Host response to xenograft ECM implantation is not different between the shoulder and body wall sites in the rat model.
abstract: In the context of tendon and ligament repair, mechanical loading and the presence of joint synovial fluid are known to profoundly influence the form and function of the repair tissue and potentially the host response to biomaterials. Previously, we demonstrated that a xenograft extra cellular matrix (ECM) scaffold implanted in the rat shoulder elicited a unique host response from that seen in the body wall. However, the host response to xenografts implanted in shoulders with a tendon/capsule injury was not different from xenografts implanted in shoulders with no injury. In the current study, we hypothesized that varying clinically relevant surgical and environmental factors would introduce significant differences in host response to xenograft implantation at the shoulder. Contrary to our hypothesis, we found no significant differences in host response between any shoulder implantation conditions or between shoulder and body wall implantation in the rat model. These findings suggest that there is no advantage to using an orthotopic shoulder model to investigate the host response to rotator cuff scaffold materials in the rat model, and due to the insensitivity of its host response to various clinically relevant surgical conditions, may suggest that the rat does not provide a surrogate for directly translating the host response to biomaterials to the human application.
authors.affiliation: Department of Biomedical Engineering and the Orthopaedic Research Center, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA.
authors.forename: Diane R
authors.initials: DR
authors.lastname: Leigh
authors.forename: Mena
authors.initials: M
authors.lastname: Mesiha
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Baker
authors.forename: Esteban
authors.initials: E
authors.lastname: Walker
authors.forename: Kathleen A
authors.initials: KA
authors.lastname: Derwin
mesh_terms: D000818:Animals; D005109:Extracellular Matrix / Q000637:transplantation*; D005206:Fascia Lata / Q000637:transplantation; D006801:Humans; D008297:Male; D023421:Models, Animal; D051381:Rats; D011917:Rats, Inbred Lew; D012782:Shoulder / Q000502:physiology / Q000601:surgery*; D014183:Transplantation, Heterologous / Q000502:physiology*; D016474:Weight-Bearing