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- Abadpour, Shadab, et al.
(author)
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Adipose-Derived Stromal Cells Preserve Pancreatic Islet Function in a Transplantable 3D Bioprinted Scaffold
- 2023
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In: Advanced healthcare materials. - 2192-2640 .- 2192-2659. ; 12:32
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Journal article (peer-reviewed)abstract
- Intra-portal islet transplantation is currently the only clinically approved beta cell replacement therapy, but its outcome is hindered by limited cell survival due to a multifactorial reaction against the allogeneic tissue in liver. Adipose-derived stromal cells (ASCs) can potentially improve the islet micro-environment by their immunomodulatory action. The challenge is to combine both islets and ASCs in a relatively easy and consistent long-term manner in a deliverable scaffold. Manufacturing the 3D bioprinted double-layered scaffolds with primary islets and ASCs using a mix of alginate/nanofibrillated cellulose (NFC) bioink is reported. The diffusion properties of the bioink and the supportive effect of human ASCs on islet viability, glucose sensing, insulin secretion, and reducing the secretion of pro-inflammatory cytokines are demonstrated. Diabetic mice transplanted with islet-ASC scaffolds reach normoglycemia seven days post-transplantation with no significant difference between this group and the group received islets under the kidney capsules. In addition, animals transplanted with islet-ASC scaffolds stay normoglycemic and show elevated levels of C-peptide compared to mice transplanted with islet-only scaffolds. The data present a functional 3D bioprinted scaffold for islets and ASCs transplanted to the extrahepatic site and suggest a possible role of ASCs on improving the islet micro-environment.
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- Amoroso, Matteo, 1984, et al.
(author)
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Functional and morphological studies of in vivo vascularization of 3D-bioprinted human fat grafts
- 2021
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In: Bioprinting. - : Elsevier BV. - 2405-8866. ; 23
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Journal article (peer-reviewed)abstract
- Three-dimensional (3D) bioprinting offers the ability to design and biofabricate 3D structures based on autologous fat; however, the lack of vascularization in larger 3D-bioprinted constructs represents a limiting factor that hampers translation of this technology from bench to bedside. 3D bioprinting using microfractured fat mixed with nanocellulose–alginate hydrogel can promote vascularization through connections of fragments of vessels included in the fat. In this study, we determined the perfusion and diffusion characteristics of 3D-bioprinted fat constructs using magnetic resonance imaging (MRI) and assessed correlations between perfusion and angiogenesis within the printed constructs. Microfractured human fat from liposuction was printed with tunicate nanocellulose–alginate hydrogel, followed by transplantation of the constructs (10 × 10 × 3 mm) into nude mice that underwent longitudinal MRI for up to 99 days. Confirmation of vascularization was undertaken using immunohistochemical and histologic analyses. Before implantation, the constructs contained abundant fat tissue and fragments of human blood vessels (CD31+ and Ku80+), with subsequent in vivo MRI analysis following transplantation indicating low perfusion and suggesting their continued survival mainly by diffusion. Additionally, we observed a high diffusion coefficient (~2 × 10−3 mm2/s) that was preserved throughout the observation period. Following explantation, evaluation revealed that the constructs displayed preserved histology along with a mixture of human (Ku80+) and murine (Ku80−) erythrocyte-containing vessels. These results demonstrated successful interconnection of blood-vessel fragments from microfractured human fat via angiogenesis to form a vascular network with the host circulation, thereby confirming vascularization of the 3D-bioprinted fat constructs.
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- Apelgren, Peter, et al.
(author)
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Long-term in vivo integrity and safety of3D-bioprinted cartilaginous constructs
- 2021
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In: Journal of Biomedical Materials Research Part B-Applied Biomaterials. - : Wiley. - 1552-4973 .- 1552-4981. ; 109:1, s. 126-136
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Journal article (peer-reviewed)abstract
- Long-term stability and biological safety are crucial for translation of 3D-bioprinting technology into clinical applications. Here, we addressed the long-term safety and stability issues associated with 3D-bioprinted constructs comprising a cellulose scaffold and human cells (chondrocytes and stem cells) over a period of 10 months in nude mice. Our findings showed that increasing unconfined compression strength over time significantly improved the mechanical stability of the cell-containing constructs relative to cell-free scaffolds. Additionally, the cell-free constructs exhibited a mean compressive stress and stiffness (compressive modulus) of 0.04 +/- 0.05 MPa and 0.14 +/- 0.18 MPa, respectively, whereas these values for the cell-containing constructs were 0.11 +/- 0.08 MPa (p= .019) and 0.53 +/- 0.59 MPa (p= .012), respectively. Moreover, histomorphologic analysis revealed that cartilage formed from the cell-containing constructs harbored an abundance of proliferating chondrocytes in clusters, and after 10 months, resembled native cartilage. Furthermore, extension of the experiment over the complete lifecycle of the animal model revealed no signs of ossification, fibrosis, necrosis, or implant-related tumor development in the 3D-bioprinted constructs. These findings confirm the in vivo biological safety and mechanical stability of 3D-bioprinted cartilaginous tissues and support their potential translation into clinical applications.
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- Apelgren, Peter, et al.
(author)
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Skin Grafting on 3D Bioprinted Cartilage Constructs In Vivo
- 2018
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In: Plastic and Reconstructive Surgery - Global Open. - 2169-7574. ; 6:9
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Journal article (peer-reviewed)abstract
- Background: Three-dimensional (3D) bioprinting of cartilage is a promising new technique. To produce, for example, an auricle with good shape, the printed cartilage needs to be covered with skin that can grow on the surface of the construct. Our primary question was to analyze if an integrated 3D bioprinted cartilage structure is a tissue that can serve as a bed for a full-thickness skin graft. Methods: 3D bioprinted constructs (10x10x1.2mm) were printed using nanofibrillated cellulose/alginate bioink mixed with mesenchymal stem cells and adult chondrocytes and implanted subcutaneously in 21 nude mice. Results: After 45 days, a full-thickness skin allograft was transplanted onto the constructs and the grafted construct again enclosed subcutaneously. Group 1 was sacrificed on day 60, whereas group 2, instead, had their skin-bearing construct uncovered on day 60 and were sacrificed on day 75 and the explants were analyzed morphologically. The skin transplants integrated well with the 3D bioprinted constructs. A tight connection between the fibrous, vascularized capsule surrounding the 3D bioprinted constructs and the skin graft were observed. The skin grafts survived the uncovering and exposure to the environment. Conclusions: A 3D bioprinted cartilage that has been allowed to integrate in vivo is a sufficient base for a full-thickness skin graft. This finding accentuates the clinical potential of 3D bioprinting for reconstructive purposes.
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- Apelgren, Peter, et al.
(author)
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Vascularization of tissue engineered cartilage-Sequential in vivo MRI display functional blood circulation
- 2021
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In: Biomaterials. - : Elsevier BV. - 0142-9612 .- 1878-5905. ; 276
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Journal article (peer-reviewed)abstract
- Establishing functional circulation in bioengineered tissue after implantation is vital for the delivery of oxygen and nutrients to the cells. Native cartilage is avascular and thrives on diffusion, which in turn depends on proximity to circulation. Here, we investigate whether a gridded three-dimensional (3D) bioprinted construct would allow ingrowth of blood vessels and thus prove a functional concept for vascularization of bioengineered tissue. Twenty 10 x 10 x 3-mm 3Dbioprinted nanocellulose constructs containing human nasal chondrocytes or cell-free controls were subcutaneously implanted in 20 nude mice. Over the next 3 months, the mice were sequentially imaged with a 7 T small-animal MRI system, and the diffusion and perfusion parameters were analyzed. The chondrocytes survived and proliferated, and the shape of the constructs was well preserved. The diffusion coefficient was high and well preserved over time. The perfusion and diffusion patterns shown by MRI suggested that blood vessels develop over time in the 3D bioprinted constructs; the vessels were confirmed by histology and immunohistochemistry. We conclude that 3D bioprinted tissue with a gridded structure allows ingrowth of blood vessels and has the potential to be vascularized from the host. This is an essential step to take bioengineered tissue from the bench to clinical practice.
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- Säljö, Karin, 1981, et al.
(author)
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Long-term in vivo survival of 3D-bioprinted human lipoaspirate-derived adipose tissue: proteomic signature and cellular content
- 2022
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In: Adipocyte. - : Informa UK Limited. - 2162-397X .- 2162-3945. ; 11:1, s. 34-46
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Journal article (peer-reviewed)abstract
- Three-dimensional (3D)-bioprinted lipoaspirate-derived adipose tissue (LAT) is a potential alternative to lipo-injection for correcting soft-tissue defects. This study investigated the long-term in vivo survival of 3D-bioprinted LAT and its proteomic signature and cellular composition. We performed proteomic and multicolour flow cytometric analyses on the lipoaspirate and 3D-bioprinted LAT constructs were transplanted into nude mice, followed by explantation after up to 150 days. LAT contained adipose-tissue-derived stem cells (ASCs), pericytes, endothelial progenitor cells (EPCs) and endothelial cells. Proteomic analysis identified 6,067 proteins, including pericyte markers, adipokines, ASC secretome proteins, proangiogenic proteins and proteins involved in adipocyte differentiation and developmental morphogenic signalling, as well as proteins not previously described in human subcutaneous fat. 3D-bioprinted LAT survived for 150 days in vivo with preservation of the construct shape and size. Furthermore, we identified human blood vessels after 30 and 150 days in vivo, indicating angiogenesis from capillaries. These results showed that LAT has a favourable proteomic signature, contains ASCs, EPCs and blood vessels that survive 3D bioprinting and can potentially facilitate angiogenesis and successful autologous fat grafting in soft-tissue reconstruction.
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- Säljö, Karin, 1981, et al.
(author)
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Successful engraftment, vascularization, and In vivo survival of 3D-bioprinted human lipoaspirate-derived adipose tissue
- 2020
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In: Bioprinting. - : Elsevier BV. - 2405-8866. ; 17
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Journal article (peer-reviewed)abstract
- Autologous fat grafting is commonly used for correction of soft-tissue deformities, despite a high rate of graft resorption and nutrition-supply challenges. Three-dimensional (3D)-bioprinting techniques enable tailor-made architecture of grafts and promote vascularization. In recent years, the importance of adipose tissue-derived stromal/stem cells (ASCs) for graft survival has become evident. This study investigated the printability of mechanically processed lipoaspirate containing ASCs, as well as in vivo survival and neovascularisation of the 3D-bioprinted grafts. Human lipoaspirate-derived adipose tissue was 3D bioprinted in alginate/nanocellulose bioink, implanted into nude mice, and harvested at days 3, 7, and 30, respectively. The processed lipoaspirate showed high viability and good printability when combined with alginate/nanocellulose, and the 3D-bioprinted grafts contained intact vascular structures and a high density of mature adipocytes before and after engraftment. After 30 days in vivo, novel blood vessels were present on the graft surface, showing signs of angiogenesis into the graft, as well as vascularization in the centre of the tissue. Moreover, histologic and immunohistochemical characterisation confirmed the presence of potential ASCs during the first week in vivo. These results demonstrated that human lipoaspirate-derived adipose tissue showed high printability, survived 3D bioprinting and engraftment in vivo, and displayed macroscopic and microscopic evidence of vascularization.
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| 15. |
- Thayer, Patrick Scott, et al.
(author)
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Bioprinting of cartilage and skin tissue analogs utilizing a novel passive mixing unit technique for bioink precellularization
- 2018
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In: Journal of Visualized Experiments. - : MyJove Corporation. - 1940-087X. ; 2018:131
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Journal article (peer-reviewed)abstract
- Bioprinting is a powerful technique for the rapid and reproducible fabrication of constructs for tissue engineering applications. In this study, both cartilage and skin analogs were fabricated after bioink pre-cellularization utilizing a novel passive mixing unit technique. This technique was developed with the aim to simplify the steps involved in the mixing of a cell suspension into a highly viscous bioink. The resolution of filaments deposited through bioprinting necessitates the assurance of uniformity in cell distribution prior to printing to avoid the deposition of regions without cells or retention of large cell clumps that can clog the needle. We demonstrate the ability to rapidly blend a cell suspension with a bioink prior to bioprinting of both cartilage and skin analogs. Both tissue analogs could be cultured for up to 4 weeks. Histological analysis demonstrated both cell viability and deposition of tissue specific extracellular matrix (ECM) markers such as glycosaminoglycans (GAGs) and collagen I respectively.
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