Based on decellularisation and cleaning processes of trabecular bone and fibrocartilage, an osteochondral allograft has been developed. The chemical process, established thanks to bone and fibrocartilage data, included an efficient viroinactivation step. The raw material was a tibial plateau collected during knee arthroplasty, cut in cylinders strictly selected (>2mm cartilage height and total height between 10 and 16mm). The grafts were freeze-dried and gamma sterilised.Background
Material
The objective was to evaluate the benefit that could be obtained in terms of pain and efficacy with processed segmental allografts on 20 patients in meniscal repair treatment. Segmental meniscal allografts were extracted from tibial plateaux during total knee arthroplasties on lateralised osteoarthritis and selected on macroscopic integrity criteria. They underwent decellularisation and deproteinisation processes to obtain a sterile collagenous matrix with glycosaminoglycans removal. Under arthroscopy, the grafts (50mm length) were fixed at the posterior horn and at the meniscosynovial wall. The main evaluation criterion was the IKDC subjective knee score evolution. Secondary criteria were the meniscus morphology (Magnetic Resonance Imaging after 12 months) and the recellularisation (biopsy after 1 year).Background
Methods
Meniscal tears are among the most common knee injuries. To preserve as much as possible the joint, partial and total meniscal replacements are necessary. To combine the biocompatibility and mechanical resistance of meniscus allograft with the disponibility of synthetic substitutes, an acellular, viroinactivated and sterile scaffold with well-preserved structure has been developed based on PHOENIX process. Human menisci were collected from living donors undergoing total knee arthroplasty. They underwent chemical treatments, freeze-drying and gamma irradiation. Decellularisation of menisci and preservation of the matrix structure were explored by histological studies. Meniscal scaffold ultrastructure was analysed by scanning electron microscopy. Biomechanical studies were also conducted. Scaffold viroinactivation was investigated by viral clearance studies. Finally, the allografts were cultured for 4 weeks with Mesenchymal Stem Cells (CSM); cells viability and proliferation were assessed histologically and by confocal microscopy following stainings.Background
Methods
Amniotic membrane (AM) and amnion/chorion foetal membranes (ACM) are mainly composed of collagen & laminin layers and constitute relatively new materials to the dental market. They have proven effective for periodontal treatments such as Guided Tissue Regeneration (GTR) [1–3]. Based on our expertise in the field of lyophilisation & securisation of human bone allograft (Phoenix® process), we aimed to develop our own process applied to ACM and to control its Human placentas were donated under informed consent. ACM were separated from placenta and processed with a proprietary AMTRIX (TBF) Process. Resulting product was called ACMTRIX. The effectiveness of ACMTRIX in GTR was evaluated using an
Empty defect (2 animals), ACMTRIX apposed onto the defect (4 animals), 3 Bone substitutes (allogenic – mineralized cortical bone powder (Phoenix®); demineralized cancellous bone powder mixed with hydroxyapatite and demineralized bone matrix (DBM) cancellous block) filled in the defect and covered by ACMTRIX (4 animals). One animal per study group was sacrificed after 8 weeks, all others after 8 weeks. Evaluations were performed by: macroscopic observations, X Ray micro-CT, and histological analysis. For all groups using ACMTRIX, no major sign of inflammation were observed macroscopically and histologically. Moreover, bone tissue was already mature from 8 weeks and bone filling was slight to moderate. The higher mean rate of mineralization was obtained for the group associating DBM cancellous block + ACMTRIX. Although a xenogenic material, ACMTRIX was very well integrated without significant inflammatory reaction compared to empty defect and fully integrated in subcutaneous area. The mineralization was superior with DBM cancellous block probably thanks to the stabilization of the material in the defect. Used alone, ACMTRIX has no osteogenic potential. In conclusion, ACMTRIX has the potential to function as barrier for GTR and the unique properties associated with this material can augment its potential as a matrix for periodontal regeneration.
