Decellularized bovine cotyledons may serve as biological scaffolds with preserved vascular arrangement

Abstract

Technically produced scaffolds are common to establish transplantable tissues for regenerative medicine, but also biological ones that are closer to the natural condition become of interest. Placentas are promising, because they represented available, complete organs with rich extracellular matrix (ECM) and well-developed vasculature that easily could build anastomoses to a host's organ. Only placentas from larger animal models such as the bovine meet the dimensions large enough for most organs but are not adequately described yet. We here studied the nature of the ECM in 27 natural and decellularized bovine cotyledons, that is, the fetal part of the placentomes, by means of histology, immunohistochemistry, and electron microscopy. Successful decellularization was done by perfusion with 0.01%, 0.1%, and 0.5% sodium dodecyl sulfate each and subsequent immersion in 1% Triton X-100, resulting in a removal of cells and DNA, whereas the structure of the allantochorionic surface and villi was preserved. Although some fibres disappeared, also the arrangement of the main ECM proteins was largely similar before and after decellularization: Along the larger vessels, a densely packed network of thick fibres occurred, organized in layers without cells or spaces in between. Collagen IV, fibronectin, and laminin contributed to those areas. In contrast, collagen I and III characterized the meshwork of medium-sized and thin fibres in the mesenchyme, respectively. In conclusion, decellularized bovine cotyledons indeed had characteristics of a biological scaffold and provide an interesting alternative to develop large-scale scaffolds with complex vascular architecture for tissue engineering purposes.

Optimization of Canine Placenta Decellularization: An Alternative Source of Biological Scaffolds for Regenerative Medicine

“…Recently, Barreto et al [2018] characterized bovine placentas as a tool for use as a biological scaffold, with possibilities of recellularization due to preservation of vascular structures in the decellularization process. Finally, we aim to standardize the decellularization protocol that preserves the characteristics and structure of the placental ECM and thereby establish the appropriate protocol for the recellularization of the placental ECM.…”

“…In addition, animal placentas can be collected from castration campaigns or after delivery, causing less ethical problems than those derived from other organs, since they are discarded [Hopper et al, 2003;Barreto et al, 2018]. Considering that the canine placenta is a discarded organ after delivery and it has important components of ECM such as collagen type I, type III, and type IV, laminin, and fibronectin, the placenta has become an interesting source for biological scaffolds, even more so because of its immunogenic, antibacterial, anti-inflammatory, and angiogenic properties and rich ECM [Hong, et al, 2010;Choi et al, 2013].…”

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“…Considerando inúmeras possibilidades, a bioengenharia de tecidos vem crescendo na área de produção de "scaffolds" biológicos naturais, de origem humana ou animal, com o intuito de serem empregados na medicina regenerativa (TSUCHIYA et al, 2014;KAKABADZE & KAKABADZE, 2015;BARRETO et al, 2017). A produção de "scaffolds" biológicos está diretamente relacionada com a descelularização de órgãos por inteiro ou fragmentos, preservando a estrutura do tecido, funcionalidade, arranjo vascular e a matriz extracelular (UYGUN et al, 2010;BARRETO et al, 2017).…”

“…E dependo da espécie, mantém arcabouço estrutural e complexo sistema vascular. Mesmo descelularizada, preserva as características da MEC (LEONEL et al, 2016;BARRETO et al, 2017;KAKABADZE et al, 2019).…”

“…O placentônio bovino, comparado com a placenta humana, tem tamanho razoável para enxertos, complexo sistema vascular com vasos grandes bem distribuídos e matriz extracelular preservada (BARRETO et al, 2017;KAKABADZE et al, 2019). Ainda produz com mais eficiência anastomoses após implantação, quando comparado à placenta humana (KAKABADZE; KAKABADZE, 2015).…”