| 1. |
- Amoroso, Matteo, 1984, et al.
(författare)
-
Functional and morphological studies of in vivo vascularization of 3D-bioprinted human fat grafts
- 2021
-
Ingår i: Bioprinting. - : Elsevier BV. - 2405-8866. ; 23
-
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.
|
|
| 2. |
- Apelgren, Peter, et al.
(författare)
-
Vascularization of tissue engineered cartilage-Sequential in vivo MRI display functional blood circulation
- 2021
-
Ingår i: Biomaterials. - : Elsevier BV. - 0142-9612 .- 1878-5905. ; 276
-
Tidskriftsartikel (refereegranskat)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.
|
|
| 3. |
- Chaudhary, Shilpi, et al.
(författare)
-
Adsorption of 3-(triethoxysilyl)propionitrile on a rutile TiO2(110) surface : An X-ray photoelectron spectroscopy study
- 2020
-
Ingår i: DAE Solid State Physics Symposium 2019. - : AIP Publishing. - 1551-7616 .- 0094-243X. - 9780735420250 ; 2265
-
Konferensbidrag (refereegranskat)abstract
- The adsorption of 3-(triethoxysilyl)propionitrile (TESP) on a reduced rutile TiO2(110) surface has been investigated using synchrotron-based X-ray photoelectron spectroscopy in ultrahigh vacuum (UHV). We have studied TESP adsorption on two surface preparation of rutile TiO2 (110) to explore the role of surface defects. In the first preparation, the adsorption of TESP was studied on reduced TiO2 (110) surface at room temperature. In the second experiment TESP was adsorbed on the oxygen-treated TiO2 surface to quench the oxygen vacancies generated by UHVannealing of the TiO2 crystal. The molecular footprints of the TESP molecules confirms the adsorption on both types of TiO2(110) surfaces. In the case of the reduced surface, temperature-dependent XPS measurements show the thermal stability of TESP molecules up to 600 °C. The comparison of the nitrogen and carbon lineshapes for both preparations suggests different adsorption geometries on the reduced and oxygen-dosed surfaces. To the best of our knowledge, the UHV preparations and measurements of TESP adsorption on rutile TiO2 (110) in the present study are reported for the first time.
|
|
