ABSTRACT
The aim of the study was to compare type I collagen-based and methacryloyl gelatin-based (GelMA) hydrogels by their ability to form hyaline cartilage in animals after subcutaneous implantation of scaffolds. Materials and Methods: Chondrocytes were isolated from the costal cartilage of newborn rats using 0.15% collagenase solution in DMEM. The cells was characterized by glycosaminoglycan staining with alcian blue. Chondrocyte scaffolds were obtained from 4% type I porcine atelocollagen and 10% GelMA by micromolding and then implanted subcutaneously into the withers of two groups of Wistar rats. Histological and immunohistochemical studies were performed on days 12 and 26 after implantation. Tissue samples were stained with hematoxylin and eosin, alcian blue; type I and type II collagens were identified by the corresponding antibodies. Results: The implanted scaffolds induced a moderate inflammatory response in both groups when implanted in animals. By day 26 after implantation, both collagen and GelMA had almost completely resorbed. Cartilage tissue formation was observed in both animal groups. The newly formed tissue was stained intensively with alcian blue, and the cells were positive for both types of collagen. Cartilage tissue was formed among muscle fibers. Conclusion: The ability of collagen type I and GelMA hydrogels to form hyaline cartilage in animals after subcutaneous implantation of scaffolds was studied. Both collagen and GelMA contributed to formation of hyaline-like cartilage tissue type in animals, but the chondrocyte phenotype is characterized as mixed. Additional detailed studies of possible mechanisms of chondrogenesis under the influence of each of the hydrogels are needed.
Subject(s)
Chondrocytes , Collagen , Animals , Rats , Swine , Rats, Wistar , Alcian Blue , Collagen/pharmacology , Ribs , Collagen Type IABSTRACT
In recent years, decellularized tissues have evolved into a new, full-fledged platform for the creation of tissue-engineered constructions. Extracellular matrix (ECM) of each tissue provides a unique tissue-specific microenvironment for resident cells with the structure and biochemical signaling required for their functioning. The decellularized ECM (dECM) has been established to influence cell differentiation. The review provides recent data on the composition and functions of the ECM, methods for obtaining decellularized tissues, and their application in tissue engineering depending on their physical form (scaffold, powder, or hydrogel). The effect of the matrix source, decellularization and sterilization techniques on dECM composition has been considered. Regulatory mechanisms of cell differentiation by the extracellular matrix are discussed. Differences in the protein composition of the native and decellularized materials are presented. Application of dECM in the bioink composition for regeneration of various tissues using bioprinting technologies is also considered. It has been concluded that successful application of dECM in tissue engineering and regenerative medicine requires a permanent and biologically suitable dECM source, optimized tissue decellularization protocols, improved mechanical properties of dECM-derived bioinks, and prevention of immunological reaction of the organism.
Subject(s)
Decellularized Extracellular Matrix , Tissue Engineering , Tissue Engineering/methods , Regenerative Medicine/methods , Extracellular Matrix/chemistry , Extracellular Matrix/metabolism , Hydrogels/analysis , Hydrogels/metabolism , Hydrogels/pharmacologyABSTRACT
During biofabrication, a tissue scaffold may require temporary support. The aim of this study was to develop an approach of human thyroid cartilage scaffold temporal support formation. The scaffold 3D-model was based on DICOM images. XY plane projections were used to form scaffold supporting part. To verify the technique, collagen hydrogel was chosen as the main scaffold component. Gelatin was applied for the supporting part. To test the applicability of the approach, a model of thyroid cartilage scaffold with the support was printed. The scaffold corresponded to a given model, although some discrepancy in geometry was observed during verification by computed tomography.
ABSTRACT
Experiments on F1(CBA×C57BL/6) mice with experimental metastatic melanoma B16 F10 showed that single intravenous injection of xenogeneic bone marrow mesenchymal stromal cells (BM-MSC) in a dose of 106 cells/mouse significantly increased 100-day survival rate of tumor-bearing animals. In contrast, administration of BM-MSC in a dose of 2×106 cells/ mouse reduced survival rates in comparison with the biocontrol (injection of B16 cells alone, 5×105 cells/mouse). This phenomenon can be related to in vivo participation of BM-MSC in reprogramming of resident tissue macrophages, including tumor microenvironment, towards pro- (M1) or anti-inflammatory (M2) phenotype. This is indirectly confirmed by the data on switching from activation to inhibition of ROS-producing activity of blood mononuclears and peritoneal macrophages in tumor-bearing mice in the test of luminol-dependent zymosaninduced chemiluminescence.
Subject(s)
Lung Neoplasms/therapy , Macrophages/immunology , Melanoma, Experimental/therapy , Mesenchymal Stem Cell Transplantation/methods , Mesenchymal Stem Cells/immunology , Skin Neoplasms/therapy , Administration, Intravenous , Animals , Cell Count , Cellular Reprogramming/genetics , Cellular Reprogramming/immunology , Female , Humans , Lung Neoplasms/immunology , Lung Neoplasms/mortality , Lung Neoplasms/secondary , Macrophages/pathology , Male , Melanoma, Experimental/immunology , Melanoma, Experimental/mortality , Melanoma, Experimental/secondary , Mesenchymal Stem Cells/cytology , Mice , Mice, Inbred C57BL , Mice, Inbred CBA , Reactive Oxygen Species/immunology , Reactive Oxygen Species/metabolism , Skin Neoplasms/immunology , Skin Neoplasms/mortality , Skin Neoplasms/pathology , Survival Analysis , Transplantation, Heterologous , Tumor Microenvironment/genetics , Tumor Microenvironment/immunologyABSTRACT
The study was carried out using compact neutron generators with a sealed tube operating in pulsed (neutron generator ING-031) and continuous (NG-14) modes. Neutron radiation was formed due to reaction T(d,n)(4)He. The average flow of 14-MeV neutrons was 6.6×10(9) ns(-1) for ING-031 and 1.2-1.6×10(10) n s(-1) for NG-14. Duration of an impulse was â¼1 ms and pulse frequency of 50 Hz. The gamma rays of (60)Со source with an average energy of 1.25 MeV were standard radiation. Biological efficacy was estimated using the clonogenic activity of mice melanoma B-16 cells. Comparison of biological effects of neutron irradiation in pulse and continuous modes showed no significant difference between them. RBE values of pulse (ING-031) and continuous (NG-14) neutron radiation were equal-in the range of 2.4-2.6. According to the clonogenic activity of melanoma B-16 cells no dose rate effect was observed within the studied range of neutrons doses and dose rates.
