PubMed · 10521941
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
1999. Aging and body composition.. https://pubmed.ncbi.nlm.nih.gov/10521941/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
Decellularized tissues provide biological cues owing to the wealth of structural and regulatory factors that promote angiogenesis, adipogenesis, and myogenesis and facilitate neurite outgrowth. Here, we demonstrated the advantages of decellularized adipose tissue (adipoECM) over defined collagen-based biomaterials for host tissue integration. Three batches of human adipose tissue were decellularized using a rapid decellularization protocol and analyzed using mass spectrometry. To assess the biological activity of the decellularized materials, adipoECM and a reference standard of care biomaterial (Integra®DRT, also containing collagen I and glycosaminoglycans) were implanted subcutaneously, but far from the wound bed (in anatomical potential spaces) of immunocompetent BALB/c mice. The mice were euthanized in the acute (1 day) and chronic (day 60) inflammatory reaction phases, followed by biomaterial excision and Masson’s trichrome immunohistofluorescence imaging of the paraffin-embedded specimens. Each batch of processed tissue passed a quality control check, showing a low level of donor genomic DNA, lack of nuclei, lipids, endotoxins, and bacterial contamination. Mass spectrometry revealed that all batches of decellularized tissue mainly contained collagen I and, to a lesser degree, collagen III, collagen IV, collagen V, laminin, fibrillin, fibronectin, tenascin, and elastin. No acute inflammatory reaction was observed in either material one day post-transplantation. At 60 days post-implantation, different cell types were detected in adipoECM specimens, whereas Integra®DRT remained acellular. Additional immunohistochemical staining of adipoECM revealed CD31-positive cells in the blood vessels. Mesenchymal (CD90 positive) and myeloid (CD14 positive) cells were also detected. Primary cell types involved in soft tissue healing and remodeling were found in the adipoECM-treated group. The ingrowth of blood vessels and mesenchymal cells confirmed the effective integration of adipoECM with host tissues. Our results demonstrate that decellularized adipose tissue implanted away from the wound bed possesses contextual biological activities that promote efficient integration with host tissues.
End product application is an important consideration when evaluating a material in an in vivo setting (Didisheim, Cardiovasc Pathol 1993;2:1S-2S). Small animal models allow high through-put evaluation of biocompatability. Previous preclinical evaluations have often used a rat subcutaneous model for the characterization of material-tissue interaction. Recent advances in genetic manipulation have provided mouse models with selective expression of a wide range of critical proteins. The rat model does not have many of the resources (i.e., knockouts, SCID, nude) that are present in mouse strains. The availability of these mice provides a resource to delineate the mechanisms regulating the healing associated with implants. However, before the mouse models can be used, they must be validated with respect to their ability to accurately assess tissue responses to materials. In this study the tissue responses after the implantation of expanded polytetrafluoroethylene (ePTFE) were compared between rat and mouse. Discs of ePTFE (30-microm internodal distance) were implanted in subcutaneous and epididymal fat tissue of rats (Sprague-Dawley) and mice (129-SVJ). After 5 weeks the samples were removed and evaluated for vascular density, inflammation, and fibrous encapsulation. No difference in the vessel density was observed within the peri-implant subcutaneous and adipose tissue or within the porous material. However, a significant difference was found in the number of activated macrophages and giant cells between these two species. Implants in the rat exhibited greater numbers of activated inflammatory cells in the peri-implant tissue. The data indicate that the mouse and rat provide a comparable model for evaluating angiogenesis and neovascularization associated with synthetic porous implants.
Articular cartilage exhibits little intrinsic repair capacity, and new tissue engineering approaches are being developed to promote cartilage regeneration using cellular therapies. The goal of this study was to examine the chondrogenic potential of adipose tissue-derived stromal cells. Stromal cells were isolated from human subcutaneous adipose tissue obtained by liposuction and were expanded and grown in vitro with or without chondrogenic media in alginate culture. Adipose-derived stromal cells abundantly synthesized cartilage matrix molecules including collagen type II, VI, and chondroitin 4-sulfate. Alginate cell constructs grown in chondrogenic media for 2 weeks in vitro were then implanted subcutaneously in nude mice for 4 and 12 weeks. Immunohistochemical analysis of these samples showed significant production of cartilage matrix molecules. These findings document the ability of adipose tissue-derived stromal cells to produce characteristic cartilage matrix molecules in both in vitro and in vivo models, and suggest the potential of these cells in cartilage tissue engineering.