Crosslinking with 405 nm is better for pancreatic islets than crosslinking with 365 nm UV light. Materials Pancreatic islets Porcine pancreas was digested with collagenase NB8 (Nordmark, S1745602) and then was cultured for 24 h in CMRL 1066 (Gibco, 21530-027) with 10% FBS (EUR X Molecular Biology Products, E5050-03), 100 IU/mL penicillin and 100 μg/mL streptomycin (Corning, 30-002-Cl) and 5 mM glucose (Sigma Aldrich, G8270), in 37˚C and 5% CO 2. Three cell lines were used for the study. Alpha cells αTC1.6-alphaTC1 Clone 6-alpha cell from pancreas of the Mus musculus diseased on adenoma. This cell line was a gift from A. Dobrzyń,
Background: 3D bioprinting is the future of constructing functional organs. Creating a bioactive scaffold with pancreatic islets presents many challenges. The aim of this paper is to assess how the 3D bioprinting process affects islet viability. Methods: The BioX 3D printer (Cellink), 600 μm inner diameter nozzles, and 3% (w/v) alginate cell carrier solution were used with rat, porcine, and human pancreatic islets. Islets were divided into a control group (culture medium) and 6 experimental groups (each subjected to specific pressure between 15 and 100 kPa). FDA/PI staining was performed to assess the viability of islets. Analogous studies were carried out on α-cells, β-cells, fibroblasts, and endothelial cells. Results: Viability of human pancreatic islets was as follows: 92% for alginate-based control and 94%, 90%, 74%, 48%, 61%, and 59% for 15, 25, 30, 50, 75, and 100 kPa, respectively. Statistically significant differences were observed between control and 50, 75, and 100 kPa, respectively. Similar observations were made for porcine and rat islets. Conclusions: Optimal pressure during 3D bioprinting with pancreatic islets by the extrusion method should be lower than 30 kPa while using 3% (w/v) alginate as a carrier.
SummaryStudies have shown beneficial effects of machine perfusion (MP) on early kidney function and long-term graft survival. The aim of this study was to investigate whether the type of perfusion device could affect outcome of transplantation of deceased donor kidneys. A total of 50 kidneys retrieved from 25 donors were randomized to machine perfusion using a flow-driven (FD) device (RM3; Waters Medical Inc) or a pressure-driven (PD) device (LifePort; Organ Recovery Systems), 24 of these kidneys (n = 12 pairs; 48%) were procured from expanded criteria donors (ECD). The primary endpoints were kidney function after transplantation defined using the incidence of delayed graft function (DGF), the number of hemodialysis sessions required, graft function at 12 months, and analyses of biopsy. DGF was similar in both groups (32%; 8/25). Patients with DGF in the FD group required a mean of 4.66 hemodialysis sessions versus 2.65 in the PD group (P = 0.005). Overall, 1-year graft survival was 80% (20/25) vs. 96% (24/25) in the FD and PD groups. One-year graft survival of ECD kidneys was 66% (8/12) in the FD group versus 92% (11/12) in the PD group. Interstitial fibrosis and tubular atrophy were significantly more common in the FD group -45% (5/11) vs. 0% (0/9) (P = 0.03) in PD group. There were no differences in creatinine levels between the groups. Machine perfusion using a pressure-driven device generating lower pulse stress is superior to a flow-driven device with higher pulse stress for preserving kidney function.
Type 1 diabetes (T1D) is characterized by the destruction of over 90% of the β-cells. C-peptide is a parameter for evaluating T1D. Streptozotocin (STZ) is a standard method of inducing diabetes in animals. Eight protocols describe the administration of STZ in mice; C-peptide levels are not taken into account. The aim of the study is to determine whether the STZ protocol for the induction of beta-cell mass destruction allows for the development of a stable in vivo mouse model for research into new transplant procedures in the treatment of type 1 diabetes. Materials and methods: Forty BALB/c mice were used. The animals were divided into nine groups according to the STZ dose and a control group. The STZ doses were between 140 and 400 mg/kg of body weight. C-peptide was taken before and 2, 7, 9, 12, 14, and 21 days after STZ. Immunohistochemistry was performed. The area of the islet and insulin-/glucagon-expressing tissues was calculated. Results: Mice who received 140, 160, 2 × 100, 200, and 250 mg of STZ did not show changes in mean fasting C-peptide in comparison to the control group and to day 0. All animals with doses of 300 and 400 mg of STZ died during the experiment. The area of the islets did not show any differences between the control and STZ-treated mice in groups below 300 mg. The reduction of insulin-positive areas in STZ mice did not exceed 50%. Conclusions: Streptozotocin is not an appropriate method of inducing a diabetes model for further research on transplantation treatments of type 1 diabetes, having caused the destruction of more than 90% of the β-cell mass in BALB/c mice.
Tissue engineering is a widely developing scientific field, which combines technological solutions with the biology of the living organism. Regenerative medicine that uses tools of tissue engineering offers alternative means of therapy enhancing damaged tissues or organs. One of the development directions of contemporary chemical engineering is the scientific description of novel technologies that will enable production of porous structures -with high utility for biomedical engineering. 3D printing is one of the most popular methods used to produce scaffolds for cell culture. Nowadays a research team, in which authors are currently working, is dealing with the problem of manufacturing 3D constructs that play the role of artificial organ, obtained via 3D bioprinting. In the current article we present the possibilities and limitations of 3D bioprinting method in the context of possible application of manufactured structures as fully functional organs.
StreszczenieInżynieria tkankowa stanowi dynamicznie rozwijającą się dziedzinę nauki łączącą rozwiązania techniki z biologią żywe-go organizmu. Medycyna regeneracyjna, korzystając z narzędzi inżynierii tkankowej, oferuje alternatywne podejście do terapii wspomagających odbudowę zniszczonych tkanek czy narządów. Jednym z kierunków rozwoju współczesnej inży-nierii chemicznej jest opracowanie nowoczesnych technologii umożliwiających wywarzanie struktur porowatych o wysokiej użyteczności w inżynierii biomedycznej. Wśród najbardziej popularnych metod wykorzystywanych do wytwarzania rusztowań do hodowli komórek jest technika druku 3D. Obecnie zespół badawczy, w którym pracują autorzy, opracowuje technikę wytwarzania za pomocą biodruku 3D konstruktów spełniających funkcję sztucznych narządów. W artykule przedstawiono zestawienie możliwości i ograniczeń omawianej metody biodruku 3D w kontekście możliwości zastosowania wytworzonych struktur jako funkcjonalnych sztucznych organów.
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