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Successful therapeutic strategies for wound healing rely on proper vascularization while inhibiting fibrosis. However, scaffolds designed for skin tissue engineering generally lack the biochemical cues that can enhance their vascularization without inducing fibrosis. Therefore, the objective of this work is to incorporate platelet‐rich plasma (PRP), a natural source of angiogenic growth factors, into a gelatin methacrylate (GelMA) hydrogel, yielding a bioink that can subsequently be used to 3D print a novel regenerative scaffold with defined architecture for skin wound healing. A PRP‐activated bioink is successfully 3D printed, and the resulting scaffolds present similar structural, rheological, and mechanical properties compared to GelMA‐only scaffolds. Furthermore, 3D printed PRP‐activated scaffolds facilitate controlled release of PRP‐derived growth factors for up to 14 days, presenting superior angiogenic potential in vitro (e.g., tubulogenesis assay) and in vivo (chick chorioallantoic membrane) compared to GelMA‐only scaffolds, while not inducing a myofibroblastic phenotype in fibroblasts (e.g., α‐smooth muscle actin expression). This disruptive technology offers the opportunity for a patient's autologous growth factors to be incorporated into a tailored 3D‐printed scaffold in theatre prior to implantation, as part of a single‐stage procedure, and has potential in other tissue engineering applications in which enhanced vascularization with limited fibrosis is desired. [ABSTRACT FROM AUTHOR]

Commercial cell-based skin regenerative products are highly expensive, carry the risk of rejection and require a long cell culture period to manufacture. This work describes the synthesis of bilayer films from poly(globalide) (PGl) and regenerated cellulose nanofibers (rCNFs) and their use as a cell-free scaffold to support keratinocyte attachment and proliferation. The method is simple, eco-friendly (as the cellulose precursor is obtained from agricultural waste) and of low cost. The rCNFs were produced by acid hydrolysis and PGl was obtained via enzymatic ring-opening polymerization. The bilayer films were synthesized by layer-by-layer casting at ambient temperature. All the films showed a well-defined interface between PGl and cellulose. The produced rCNF/PGl bilayer films showed cell metabolic activity far superior in comparison with pristine PGl regarding the keratinocyte growth, which illustrates the potential use of these materials in skin tissue engineering., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

There are several pathologies associated with the peritoneum, such as mesothelioma and peritonitis. Moreover, the peritoneum is widely used in ultrafiltration procedures, i.e., peritoneal dialysis, presenting advantages over hemodialysis. On the other hand, ultrafiltration failure may lead to dialysis-induced fibrosis and hypervolemia. Therefore, the pathophysiological study of this tissue is of extreme biomedical importance. Studies investigating the biology of the cells dwelling in the peritoneum wall provide evidence of their plasticity and progenitor features. For instance, both mesothelial and submesothelial cells present characteristics similar to mesenchymal stem cells, including osteogenic and adipogenic differentiation potential, support of extramedullary hematopoiesis, modulation of inflammatory responses, and regulation of tumor progression. Indeed, the participation of each cell type in peritoneal pathological and physiological phenomena is still under debate, especially regarding a possible differentiation pathway connecting these peritoneal cells. The primary aim of this review is to raise this discussion. In order to do so, we will firstly provide an overview of the peritoneum anatomy, histology, and ontology, and finally we will address how a better understanding of peritoneal cell biology may contribute to future cell therapy and tissue engineering approaches., (© 2017 S. Karger AG, Basel.)

In cartilaginous tissues, perichondrium cambium layer may be the source of new cartilage. Human nasal septal perichondrium is considered to be a homogeneous structure in which some authors do not recognize the perichondrium internal zone or the cambium layer as a layer distinct from adjacent cartilage surface. In the present study, we isolated a chondrogenic cell population from human nasal septal cartilage surface zone. Nasoseptal chondrogenic cells were positive for surface markers described for mesenchymal stem cells, with exception of CD146, a perivascular cell marker, which is consistent with their avascular niche in cartilage. Although only Sox-9 was constitutively expressed, they also revealed osteogenic and chondrogenic, but not adipogenic, potentials in vitro, suggesting a more restricted lineage potential compared to mesenchymal stem cells. Interestingly, even in absence of chondrogenic growth factors in the pellet culture system, nasoseptal chondrogenic cells had a capacity to synthesize sulfated glycosaminoglycans, large amounts of collagen type II and to a lesser extent collagen type I. The spontaneous chondrogenic potential of this population of cells indicates that they may be a possible source for cartilage tissue engineering. Besides, the pellet culture system using nasoseptal chondrogenic cells may also be a model for studies of chondrogenesis., (Copyright © 2011 Elsevier B.V. All rights reserved.)