There have been several improvements to the US tissue banking industry over the past decade. Tissue banks had limited active government regulation until 1993, at which time the US Food and Drug Administration began regulatory oversight because of reports of disease transmission from allograft tissues. Reports in recent years of disease transmission associated with the use of allografts have further raised concerns about the safety of such implants. A retrospective review of allograft recall data was performed to analyze allograft recall by tissue type, reason, and year during the period from January 1994 to June 30, 2007. During the study period, more than 96.5% of all allograft tissues recalled were musculoskeletal. The reasons underlying recent musculoskeletal tissue recalls include insufficient or improper donor evaluation, contamination, recipient infection, and positive serologic tests. Infectious disease transmission following allograft implantation may occur if potential donors are not adequately evaluated or screened serologically during the prerecovery phase and if the implant is not sterilized before implantation.
"The BioCleanse® tissue sterilization process (RTI Biologics, Alachua, FL) is a non-thermal combination of mechanical and chemical processes that has been reported to inactivate or remove all sources of infectious disease transmission while not compromising the biomechanical and physiological properties of allograft bone and soft tissue [21, 22, 29, 34]. To date, there has not been a direct comparison of clinical outcomes via a randomized, prospective clinical trial with this type of sterilized allograft. "
[Show abstract][Hide abstract] ABSTRACT: PURPOSE: To compare the clinical outcomes of bone-patellar tendon-bone (BTB) allografts processed via a novel sterilization system with the traditional aseptically processed BTB allografts for anterior cruciate ligament (ACL) reconstruction. METHODS: A total of 67 patients undergoing ACL reconstruction at 6 independent investigation sites were randomized into one of two intervention groups, BioCleanse-sterilized or aseptic BTB allografts. Inclusion criteria included an acute, isolated, unilateral ACL tear, and exclusion criteria included prior ACL injury, multi-ligament reconstruction, and signs of degenerative joint disease. Post-op examiners and patients were blinded to graft type. Patients were evaluated at 6, 12, and 24 months. Clinical outcomes were compared using the IKDC, a KT-1000 knee arthrometer, level of effusion, and ranges of motion (ROM). RESULTS: After randomization, 24 patients received aseptic BTB allografts and 43 patients received BioCleanse-sterilized allografts. Significant improvement in IKDC scores (P < 0.0001) as well as KT-1000 results (P < 0.0001) was noted over the 24-month period for both groups. IKDC or KT-1000 results were not significantly different between groups at any time point. Active flexion ROM significantly improved from pre-op to 24-month follow-up (P < 0.0001) with no difference between groups at any time point. Active extension ROM did not differ significantly between the two groups. CONCLUSIONS: These results indicate that the sterilization process, BioCleanse, did not demonstrate a statistical difference in clinical outcomes for the BTB allograft at 2 years. The BioCleanse process may provide surgeons with allografts clinically similar to aseptically processed allograft tissue with the benefit of addressing donor-to-recipient disease. LEVEL OF EVIDENCE: II.
"have reported that scAAV-BMP2-coated allografts can heal defects comparably to autograft treatment, allograft treatment still poses some drawbacks, including the possibility of disease transmission (Mroz et al. 2008) and a lack of porosity throughout the cortices, thus limiting vascular invasion. Additionally, the nonporous cortical surfaces of allograft bone prohibit the uniform distribution of coated AAV particles (Yazici et al. 2008). "
[Show abstract][Hide abstract] ABSTRACT: Biomaterial scaffolds functionalized to stimulate endogenous repair mechanisms via the incorporation of osteogenic cues offer a potential alternative to bone grafting for the treatment of large bone defects. We first quantified the ability of a self-complementary adeno-associated viral vector encoding bone morphogenetic protein 2 (scAAV2.5-BMP2) to enhance human stem cell osteogenic differentiation in vitro. In two-dimensional culture, scAAV2.5-BMP2-transduced human mesenchymal stem cells (hMSCs) displayed significant increases in BMP2 production and alkaline phosphatase activity compared with controls. hMSCs and human amniotic-fluid-derived stem cells (hAFS cells) seeded on scAAV2.5-BMP2-coated three-dimensional porous polymer Poly(ε-caprolactone) (PCL) scaffolds also displayed significant increases in BMP2 production compared with controls during 12 weeks of culture, although only hMSC-seeded scaffolds displayed significantly increased mineral formation. PCL scaffolds coated with scAAV2.5-BMP2 were implanted into critically sized immunocompromised rat femoral defects, both with or without pre-seeding of hMSCs, representing ex vivo and in vivo gene therapy treatments, respectively. After 12 weeks, defects treated with acellular scAAV2.5-BMP2-coated scaffolds displayed increased bony bridging and had significantly higher bone ingrowth and mechanical properties compared with controls, whereas defects treated with scAAV2.5-BMP2 scaffolds pre-seeded with hMSCs failed to display significant differences relative to controls. When pooled, defect treatment with scAAV2.5-BMP2-coated scaffolds, both with or without inclusion of pre-seeded hMSCs, led to significant increases in defect mineral formation at all time points and increased mechanical properties compared with controls. This study thus presents a novel acellular bone-graft-free endogenous repair therapy for orthotopic tissue-engineered bone regeneration.
Cell and Tissue Research 06/2011; 347(3):575-88. DOI:10.1007/s00441-011-1197-3 · 3.57 Impact Factor
"no need for additional surgery, " off the shelf " availability, size of graft material). However, significant drawbacks such as worldwide donor shortage (Greenwald et al., 2001) and associated risk of disease transmission (Mroz et al., 2008) ensure that allografting is insufficient as a viable long-term approach to bone autografting. Focus has recently switched towards the use of alternative approaches to attempt to promote and facilitate the body's own bone tissue healing ability. "
[Show abstract][Hide abstract] ABSTRACT: There is an enduring and unmet need for a bioactive, load-bearing tissue-engineering scaffold, which is biocompatible, biodegradable and capable of facilitating and promoting osteogenesis when implanted in vivo. This study set out to develop a biomimetic scaffold by incorporating osteoinductive hydroxyapatite (HA) particles into a highly porous and extremely biocompatible collagen-based scaffold developed within our laboratory over the last number of years to improve osteogenic performance. Specifically we investigated how the addition of discrete quantities of HA affected scaffold porosity, interconnectivity, mechanical properties, in vitro mineralisation and in vivo bone healing potential. The results show that the addition of HA up to a 200 weight percentage (wt%) relative to collagen content led to significantly increased scaffold stiffness and pore interconnectivity (approximately 10 fold) while achieving a scaffold porosity of 99%. In addition, this biomimetic collagen-HA scaffold exhibited significantly improved bioactivity, in vitro mineralisation after 28 days in culture, and in vivo healing of a critical-sized bone defect. These findings demonstrate the regenerative potential of these biodegradable scaffolds as viable bone graft substitute materials, comprised only of bone’s natural constituent materials, and capable of promoting osteogenesis in vitro and in vivo repair of critical-sized bone defects.
European cells & materials 07/2010; 20. · 4.89 Impact Factor
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