RESUMEN
Regenerative repair of the vascular system is challenging from the perspectives of translational medicine and tissue engineering. There are fundamental hurdles in front of creating bioartificial arteries, which involve recaputilation of the three-layered structure under laboratory settings. Obtaining and maintaining smooth muscle characteristics is an important limitation, as the transdifferentiated cells fail to display mature phenotype. This study aims to shed light on the smooth muscle differentiation of human adipose stem cells (hASCs). To this end, we first acquired hASCs from lipoaspirate samples. Upon characterization, the cells were induced to differentiate into smooth muscle (SM)-like cells using a variety of inducer combinations. Among all, TGFß1/BMP4 combination had the highest differentiation efficiency, based on immunohistochemical analyses. hSM-like cell samples were compared to hASCs and to the positive control, human coronary artery-smooth muscle cells (hCA-SMCs) through gene transcription profiling. Microarray findings revealed the activation of gene groups that function in smooth muscle differentiation, signaling pathways, extracellular modeling and cell proliferation. Our results underline the effectiveness of the growth factors and suggest some potential variables for detecting the SM-like cell characteristics. Evidence in transcriptome level was used to evaluate the TGFß1/BMP4 combination as a previously unexplored effector for the smooth muscle differentiation of adipose stem cells.
Asunto(s)
Adipocitos/citología , Diferenciación Celular , Células Madre Mesenquimatosas/citología , Miocitos del Músculo Liso/citología , Transcriptoma , Adipocitos/efectos de los fármacos , Adipocitos/metabolismo , Proteína Morfogenética Ósea 4/farmacología , Células Cultivadas , Femenino , Regulación del Desarrollo de la Expresión Génica , Humanos , Células Madre Mesenquimatosas/efectos de los fármacos , Células Madre Mesenquimatosas/metabolismo , Persona de Mediana Edad , Miocitos del Músculo Liso/efectos de los fármacos , Miocitos del Músculo Liso/metabolismo , Factor de Crecimiento Transformador beta/farmacologíaRESUMEN
Regenerative medicine is an interdisciplinary field that aims to regenerate the lost or diseased tissues through the combinational use of cells, biomolecules and/or biomaterials. Injectable biomaterials have been comprehensively evaluated for use in this field for their prominent properties, such as ease of handling, providing a better integration of the native tissue by filling irregular defects and having controllable chemical and physical properties. This class of biomaterials can be developed from natural or synthetic origin materials, decellularized matrices or from combinations of materials to form composites. Injectable biomaterials enable minimally invasive approach when compared with traditional open surgeries, which can reduce the cost, and speed up the recovery time for the patients. Cells, growth factors and/or bioactive molecules can be effectively delivered to the target tissue using injectable biomaterials, making them desirable for a number of clinical applications. This chapter gives an overview on injectable biomaterials and their clinical applications in soft, hard, and cardiovascular tissue regeneration.
Asunto(s)
Materiales Biocompatibles , Medicina Regenerativa/tendencias , Humanos , Regeneración , Ingeniería de TejidosRESUMEN
CMC and CMC-PVA were blended either with type I collagen, BSA or CS to obtain biocompatible membranes for evaluation as potential hepatocyte culture substrates. Pure and modified forms of CMC showed distinct surface, mechanical, and cell attachment properties. While the hydrophilicity decreased, the mechanical stability and the porosity of CMC membranes increased after blending. Serum proteins were adsorbed by all types of membranes. Among eight membranes tested, collagen-modified CMC was found to be a suitable membrane material for hepatocyte culture, in terms of mechanical and cell interaction properties.
Asunto(s)
Carboximetilcelulosa de Sodio/química , Hepatocitos/citología , Hígado Artificial , Ensayo de Materiales , Alcohol Polivinílico/química , Animales , Técnicas de Cultivo de Célula , Supervivencia Celular , Células Cultivadas , Hepatocitos/enzimología , Masculino , Microscopía de Fuerza Atómica , Ratas , Suero , Espectroscopía Infrarroja por Transformada de Fourier , Agua/químicaRESUMEN
In this study, we synthesized poly(N-vinylcaprolactam)-g-collagen (PNVCL-g-Col) by grafting collagen with carboxyl group-terminated thermosensitive PNVCL-COOH. The resulting biopolymer was evaluated for its structural, thermal, and rheological properties. Aqueous solutions of PNVCL-g-Col exhibited a temperature-dependent phase transition around human physiological temperature (at â¼38.5 °C), and temperature-dependent tunability. PNVCL-g-Col exhibited temperature-dependent release of the model drugs, lidocaine hydrochloride and bovine serum albumin. Thus, PNVCL-g-Col biopolymer may have wide potential use in various biomedical applications, including controlled release and tissue engineering.
Asunto(s)
Caprolactama/análogos & derivados , Colágeno/química , Portadores de Fármacos/química , Portadores de Fármacos/síntesis química , Polímeros/química , Temperatura , Animales , Caprolactama/química , Bovinos , Técnicas de Química Sintética , Liberación de Fármacos , Humanos , Lidocaína/química , Reología , Albúmina Sérica Bovina/química , Agua/químicaRESUMEN
Encapsulation techniques have the potential to protect hepatocytes from cryoinjury. In this study, we comparatively evaluated the viability and metabolic function of primary rat hepatocytes encapsulated in calcium alginate microbeads, in chitosan tripolyphosphate beads, and in three-layered alginate-chitosan-alginate (ACA) microcapsules, before and after cryopreservation at -80°C and in liquid nitrogen (LN2) for 1 and 3 months. Findings demonstrated that LN2 was atop of -80°C in regard to preservation of viability (> 90%) and hepatic functions. LN2-cryopreserved hepatocytes encapsulated in ACA microcapsules retained metabolic function post-thawing, with > 90% of the albumin, total protein and urea syntheses activities, and > 80% of oxidative function.
Asunto(s)
Alginatos/farmacología , Cápsulas/química , Quitosano/farmacología , Criopreservación , Hepatocitos/efectos de los fármacos , Albúminas/biosíntesis , Alginatos/química , Animales , Supervivencia Celular/efectos de los fármacos , Células Inmovilizadas , Quitosano/análogos & derivados , Sistema Enzimático del Citocromo P-450/metabolismo , Congelación , Ácido Glucurónico/química , Ácido Glucurónico/farmacología , Hepatocitos/citología , Hepatocitos/metabolismo , Ácidos Hexurónicos/química , Ácidos Hexurónicos/farmacología , Hígado Artificial , Masculino , Nitrógeno , Fosforilación Oxidativa , Cultivo Primario de Células , Ratas , Ratas Wistar , Urea/metabolismoRESUMEN
The objective of this study was to develop an engineered rat hyaline cartilage by culturing articular chondrocytes on three-dimensional (3D) macroporous poly(DL-lactic-co-glycolic acid) (PLGA) sponges under chondrogenic induction and microgravity bioreactor conditions. Experimental groups consisted of 3D static and dynamic cultures, while a single cell monolayer (2D) served as the control. The effect of seeding conditions (static vs. dynamic) on cellularization of the scaffolds was investigated. MTT assay was used to evaluate the number of viable cells in each group at different time points. Formation of a hyaline-like cartilage was evaluated for up to 4 weeks in vitro. While 2D culture resulted in cell sheets with very poor matrix production, 3D culture was in the favor of tissue formation. A higher yield of cell attachment and spatially uniform cell distribution was achieved when dynamic seeding technique was used. Dynamic culture promoted cell growth and infiltration throughout the sponge structure and showed the formation of cartilage tissue, while chondrogenesis appeared attenuated more towards the outer region of the constructs in the static culture group. Medium supplemented with TGF-beta 1 (5 ng/ml) had a positive impact on proteoglycan production as confirmed by histochemical analyses with Alcian blue and Safranin-O stainings. Formation of hyaline-like tissue was demonstrated by immunohistochemistry performed with antibodies against type II collagen and aggrecan. SEM confirmed higher level of cellularization and cartilage tissue formation in bioreactor cultures induced by TGF-beta 1. The data suggest that PLGA sponge inside rotating bioreactor with chondrogenic medium provides an environment that mediates isolated rat chondrocytes to redifferentiate and form hyaline-like rat cartilage, in vitro.
Asunto(s)
Cartílago Articular , Ingeniería de Tejidos , Factor de Crecimiento Transformador beta1 , Animales , Materiales Biocompatibles , Reactores Biológicos , Cartílago Articular/citología , Cartílago Articular/crecimiento & desarrollo , Cartílago Articular/metabolismo , Procesos de Crecimiento Celular , Movimiento Celular/efectos de los fármacos , Condrogénesis/efectos de los fármacos , Colágeno Tipo II/biosíntesis , Colágeno Tipo II/metabolismo , Inmunohistoquímica , Microscopía Electrónica de Rastreo , Polímeros , Proteoglicanos/biosíntesis , Proteoglicanos/metabolismo , Ratas , Técnicas de Cultivo de Tejidos , Factor de Crecimiento Transformador beta1/farmacología , IngravidezRESUMEN
In this study, chitosan [(1 --> 4) linked 2-amino-2-deoxy-beta-D-glucopyranose] beads were prepared by interacting this polycation (> 90% deacetylated) with the tripolyphosphate (TPP) polyanion. The resulting chitosan-TPP beads (C) were modified either by coating with sodium alginate (CA) or by cross-linking with glutaraldehyde (CGA). The in vitro degradation of C beads was found to be faster than its CA and CGA counterparts. C beads degraded faster at pH 6.5, compared to pH 7.4 conditions. At pH 7.4, about 41%, 37% and 10% of dry mass loss after 12 months was determined for C, CA and CGA, respectively. At pH 6.5, the dry mass loss of CA and CGA after the same period of time was found to be 73% and 37%, respectively. However, C beads completely degraded at pH 6.5 after 8 months of in vitro incubation. The in vivo biodegradation experiments were performed on Wistar rats (n = 24) for a duration of 6 months. No sign of fibrotic capsule formation was observed around any of the implanted beads at 2 and 6 months post-transplantation. At 2 months, the in vivo-degradation was slow-going and the beads in all groups were intact; CGA beads had more tissue reaction than C and CA beads at this time point. While the C beads had almost completely degraded after 6 months, the biodegradation process in CA and CGA beads was progressing. Histomorphometric analysis revealed that the in vivo biodegradation was in the order of C (approximately 85%) > CA (approximately 50%) > CGA (approximately 25%) after 6 months. Neovascularization was observed at the vicinity of the bead implants close to major blood vessels, both at 2 and 6 months time-points.