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Hudson, MA, United States

Peterson D.R.,DRP Biomedical | Ohashi K.L.,Microvascular Tissues | Aberman H.M.,Advanced Biological Concepts | Piza P.A.,Golden Orthopedic | And 6 more authors.
Journal of Shoulder and Elbow Surgery

Background: A new scaffold design combined with a peptide growth factor was tested prospectively for safety and for improved tendon healing in sheep. Methods: The infraspinatus tendon was detached and then surgically repaired to the humerus using sutures and anchors in 50 adult sheep. The repairs in 40 of these sheep were reinforced with a scaffold containing F2A, a peptide mimetic of basic fibroblast growth factor. The sheep were examined after 8 or 26 weeks with magnetic resonance imaging, full necropsy, and histopathologic analysis. A second cohort of 30 sheep underwent surgical repair-20 with scaffolds containing F2A. The 30 shoulders were tested mechanically after 8 weeks. Results: The scaffold and F2A showed no toxicity. Scaffold-repaired tendons were 31% thicker than surgically repaired controls (P = .037) at 8 weeks. There was more new bone formed at the tendon footprint in sheep treated with F2A. Surgically repaired tendons delaminated from the humerus across 14% of the footprint area. The extent of delamination decreased to 1.3% with increasing doses of F2A (P = .004). More of the repair tissue at the footprint was tendon-like in the peptide-treated sheep. On mechanical testing, only 7 shoulders tore at the repair site. The repairs in the other 23 shoulders were already stronger than the midsubstance tendon at 8 weeks. Conclusions: The new scaffold and peptide safely improved tendon healing. © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Source

Hackett E.S.,Colorado State University | Harilal D.,Kensey Nash Corporation | Bowley C.,Kensey Nash Corporation | Hawes M.,Charter Preclinical Services | And 2 more authors.
Journal of Biomedical Materials Research - Part B Applied Biomaterials

Surgical mesh composed of extracellular matrix promotes healing of difficult soft tissue and orthopedic repairs in preclinical and clinical trials. In this study, a novel extracellular matrix prepared from porcine hydrated dermis was evaluated in an in vivo fascial defect model in sheep. Fascial defects were created, and then acutely repaired with surgical mesh. Healed surgical sites were evaluated grossly, histologically, and biomechanically at 6 and 12 weeks. Porcine hydrated dermis extracellular matrix performed favorably compared to negative control empty defects and native fascia, with minimal gross adhesion, low histologic inflammatory scores, and significantly greater tensile strength of the healing surgical site when compared with native fascia. © 2010 Wiley Periodicals, Inc. Source

Proffen B.L.,Harvard University | Perrone G.S.,Harvard University | Fleming B.C.,University of Rhode Island | Sieker J.T.,Harvard University | And 3 more authors.
Journal of Biomaterials Applications

Reconstituted extracellular matrix (ECM)-derived scaffolds are commonly utilized in preclinical tissue engineering studies as delivery vehicles for cells and growth factors. Translation into clinical use requires identifying a sterilization method that effectively removes bacteria but does not harm scaffold function. To determine effectiveness of sterilization and impact on ECM scaffold integrity and function, low-temperature ethylene oxide and 15 kGy electron beam irradiation techniques were evaluated. Scaffold sterility was assessed in accordance to United States Pharmacopeia Chapter 71. Scaffold matrix degradation was determined in vitro using enzymatic resistance tests and gel electrophoresis. Scaffold mechanics including elastic modulus, yield stress and collapse modulus were tested. Lastly, 14 Yorkshire pigs underwent ACL transection and bio-enhanced ACL repair using sterilized scaffolds. Histologic response of ligament, synovium, and lymph nodes was compared at 4, 6, and 8 weeks. Ethylene oxide as well as electron beam irradiation yielded sterile scaffolds. Scaffold resistance to enzymatic digestion and protein integrity slightly decreased after electron beam irradiation while ethylene oxide altered scaffold matrix. Scaffold elastic modulus and yield stress were increased after electron beam treatment, while collapse modulus was increased after ethylene oxide treatment. No significant changes in ACL dimensions, in vivo scaffold resorption rate, or histologic response of synovium, ligament, and lymph nodes with either terminal sterilization technique were detectable. In conclusion, this study identifies two methods to terminally sterilize an ECM scaffold. In vitro scaffold properties were slightly changed without significantly influencing the biologic responses of the surrounding tissues in vivo. This is a critical step toward translating new tissue engineering strategies to clinical trials. © SAGE Publications. Source

Proffen B.L.,Harvard University | Perrone G.S.,Harvard University | Fleming B.C.,University of Rhode Island | Sieker J.T.,Harvard University | And 4 more authors.
Journal of Orthopaedic Research

Extracellular matrix (ECM) scaffolds have been used to enhance anterior cruciate ligament (ACL) repair in large animal models. To translate this technology to clinical care, identifying a method which effectively sterilizes the material without significantly impairing in vivo function is desirable. Sixteen Yorkshire pigs underwent ACL transection and were randomly assigned to bridge-enhanced ACL repair - primary suture repair of the ACL with addition of autologous blood soaked ECM scaffold - with either (i) an aseptically processed ECM scaffold, or (ii) an electron beam irradiated ECM scaffold. Primary outcome measures included sterility of the scaffold and biomechanical properties of the scaffold itself and the repaired ligament at 8 weeks after surgery. Scaffolds treated with 15-kGy electron beam irradiation had no bacterial or fungal growth noted, while aseptically processed scaffolds had bacterial growth in all tested samples. The mean biomechanical properties of the scaffold and healing ligament were lower in the electron beam group; however, differences were not statistically significant. Electron beam irradiation was able to effectively sterilize the scaffolds. In addition, this technique had only a minimal impact on the in vivo function of the scaffolds when used for ligament healing in the porcine model. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. Source

Fournier E.,Mx Orthopedics | Devaney R.,Mx Orthopedics | Palmer M.,Mx Orthopedics | Kramer J.,Charter Preclinical Services | And 2 more authors.
Journal of Materials Engineering and Performance

The demand for hip and knee replacement surgery is substantial and growing. Unfortunately, most joint replacement surgeries will fail within 10-25 years, thereby requiring an arduous, painful, and expensive revision surgery. To address this issue, a novel orthopedic implant coating material ("eXalt") has been developed. eXalt is comprised of super elastic nitinol wire that is knit into a three-dimensional spacer fabric structure. eXalt expands in vivo to conform to the implantation site and is porous to allow for bone ingrowth. The safety and efficacy of eXalt were evaluated through structural analysis, mechanical testing, and a rabbit implantation model. The results demonstrate that eXalt meets or exceeds the performance of current coating technologies with reduced micromotion, improved osseointegration, and stronger implant fixation in vivo. © 2014 ASM International. Source

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