| 1. |
- Amoroso, Matteo, 1984, et al.
(författare)
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Functional and morphological studies of in vivo vascularization of 3D-bioprinted human fat grafts
- 2021
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Ingår i: Bioprinting. - : Elsevier BV. - 2405-8866. ; 23
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Tidskriftsartikel (refereegranskat)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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| 2. |
- Martinez Avila, Hector, 1985, et al.
(författare)
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3D bioprinting of human chondrocyte-laden nanocellulose hydrogels for patient-specific auricular cartilage regeneration
- 2016
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Ingår i: Bioprinting. - : Elsevier BV. - 2405-8866. ; 1-2, s. 22-35
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Tidskriftsartikel (refereegranskat)abstract
- © 2016 Elsevier B.V.Auricular cartilage tissue engineering (TE) aims to provide an effective treatment for patients with acquired or congenital auricular defects. Bioprinting has gained attention in several TE strategies for its ability to spatially control the placement of cells, biomaterials and biological molecules. Although considerable advances have been made to bioprint complex 3D tissue analogues, the development of hydrogel bioinks with good printability and bioactive properties must improve in order to advance the translation of 3D bioprinting into the clinic. In this study, the biological functionality of a bioink composed of nanofibrillated cellulose and alginate (NFC-A) is extensively evaluated for auricular cartilage TE. 3D bioprinted auricular constructs laden with human nasal chondrocytes (hNC) are cultured for up to 28 days and the redifferentiation capacity of hNCs in NFC-A is studied on gene expression as well as on protein levels. 3D bioprinting with NFC-A bioink facilitates the biofabrication of cell-laden, patient-specific auricular constructs with an open inner structure, high cell density and homogenous cell distribution. The cell-laden NFC-A constructs exhibit an excellent shape and size stability as well as an increase in cell viability and proliferation during in vitro culture. Furthermore, NFC-A bioink supports the redifferentiation of hNCs and neo-synthesis of cartilage-specific extracellular matrix components. This demonstrated that NFC-A bioink supports redifferentiation of hNCs while offering proper printability in a biologically relevant aqueous 3D environment, making it a promising tool for auricular cartilage TE and many other biomedical applications.
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| 3. |
- Morales-Lopez, Alvaro, et al.
(författare)
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Impact of storage at different thermal conditions on surface characteristics of 3D printed polycaprolactone and poly(ε-caprolactone-co-p-dioxanone) scaffolds
- 2023
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Ingår i: Bioprinting. - : Elsevier B.V.. - 2405-8866. ; 33
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Tidskriftsartikel (refereegranskat)abstract
- Fused filament fabrication (FFF) is a commonly used method for producing three-dimensional scaffolds using synthetic, degradable polymers. However, there are several variables that must be considered when fabricating devices for clinical use, one of which is storage conditions after printing. While the academic community has examined the impact of FFF on mechanical and thermal properties, there has been less focus on how storage conditions would affect the surface texture of scaffolds. Our hypothesis was that the surface, thermal and physical properties of FFF scaffolds are significantly influenced by the storage conditions. We evaluated the surfaces of FFF poly (ε-caprolactone) (PCL) and poly (ε-caprolactone-co-p-dioxanone) (PCLDX) strands that were stored at 4 °C, 20 °C, and 37 °C for 28 days. We monitored surface texture, physical and thermal changes to understand the effect of storage on the strands. The implementation of scale-sensitive fractal analysis and feature parameters revealed that storage conditions at 37 °C increased the number of hills and dales, as well as the density of peaks and pits compared to 20 °C and 4 °C, for both materials. The feature roughness parameters for PCL had up to 90% higher values than those of PCLDX, which correlated with the physical and thermal properties of the materials. These differences may impact further surface-cell interaction, highlighting the need for further evaluation for faster clinical translation. Our findings emphasize the importance of considering storage conditions in the design and manufacture of FFF scaffolds and suggest that the use of feature roughness parameters could facilitate the optimization and tailoring the surface properties for specific applications. © 2023 The Authors
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| 4. |
- Säljö, Karin, 1981, et al.
(författare)
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Successful engraftment, vascularization, and In vivo survival of 3D-bioprinted human lipoaspirate-derived adipose tissue
- 2020
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Ingår i: Bioprinting. - : Elsevier BV. - 2405-8866. ; 17
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Tidskriftsartikel (refereegranskat)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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| 5. |
- Sämfors, Sanna, 1987, et al.
(författare)
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Design and biofabrication of a leaf-inspired vascularized cell-delivery device
- 2022
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Ingår i: Bioprinting. - : Elsevier BV. - 2405-8866. ; 26
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Tidskriftsartikel (refereegranskat)abstract
- We designed and biofabricated a channeled construct as a possible cell-delivery device that can be endothelialized to overcome size limitations due to oxygen diffusion. The channeled device mimicking a leaf was designed using computer-aided design software, with fluid flow through the channels visualized using simulation studies. The device was fabricated either by form casting using a custom 3D-printed plastic mold or by 3D-bioprinting using Pluronic F-127 as sacrificial ink to print the channels. The actual leaf was cast or bioprinted using hydrogel made from a mixture of tunicate cellulose nanofibers and alginate that was cross-linked in calcium chloride solution to allow a stable device. The resulting device was a 20 × 8 × 3 mm or 35 × 18 × 3 mm (length × width × height) leaf with one main channel connected to several side channels. Surface modification using periodate oxidation, followed by laminin bioconjugation, was performed to enhance endothelial cell adhesion in the channels. We subsequently used human umbilical vein endothelial cells to demonstrate the efficacy of the device for promoting endothelialization. These results indicated that the biofabricated device has great potential for use in tissue-engineering for various applications associated with the need of perfusable vasculature.
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| 6. |
- Tonda-Turo, C., et al.
(författare)
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Photocurable chitosan as bioink for cellularized therapies towards personalized scaffold architecture
- 2020
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Ingår i: Bioprinting. - : Elsevier. - 2405-8866. ; 18
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Tidskriftsartikel (refereegranskat)abstract
- Recent progresses in tissue engineering are directed towards the development of technologies able to provide personalized scaffolds recreating the defect shape in a patient specific manner. To achieve this ambitious goal, 3D bioprinting can be combined with a suitable bioink, able to create a physiological milieu for cell growth. In this work, a novel chitosan-based hydrogel was developed combining photocrosslinking and thermo-sensitive properties. Commercial chitosan (CS) was first methacrylated and then mixed with β-glycerol phosphate salt (β-GP) to impart a thermally induced phase transition. The absence of cytotoxic degradation products and the excellent biocompatibility of the developed hydrogel was confirmed through in vitro tests using different cell lines (NIH/3T3, Saos-2, SH-SY5Y). Cellularized 3D structures were obtained though 3D bioprinting technologies confirming the processability of the developed hydrogels and its unique biological properties.
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