DigitalUM :: Browsing by Subject "Tissue engineering"

Browsing by Subject "Tissue engineering"

Now showing 1 - 12 of 12

Open Access
Adipose stem cells and skeletal repair
(F. Hernández y Juan F. Madrid. Universidad de Murcia. Departamento de Biología Celular e Histología, 2013) Im, Gun-II
. Although adipose tissue has been considered a useless tissue, recent investigations have shown that it provides an abundant source of adult stem cells. Adipose stem cells (ASCs) can undergo rapid osteogenenic differentiation, which represents a promising option for bone tissue engineering and treating large bone defects. While bone marrow-derived stem cells have been more extensively studied for bone tissue engineering, a limitation exists in the harvested amount of bone marrow. As adipose tissue can provide a much greater number of adult stem cells without causing morbidity, it offers a good option as a cell source for bone tissue engineering. In this review, we discuss the definition of ASCs, the induction of osteogenic differentiation from ASCs, scaffolding materials for adipose bone tissue engineering, and in vivo models for future clinical applications.
Open Access
Advances in translational orthopaedic research with species-specific multipotent mesenchymal stromal cells derived from the umbilical cord
(Universidad de Murcia. Departamento de Biología Celular e Histología, 2021) Ramallo, Melina; Carreras Sánchez, Irene; López Fernández, Alba; Vélez, Roberto; Aguirre, Màrius; Feldman, Sara; Vives, Joaquim
Compliance with current regulations for the development of innovative medicines require the testing of candidate therapies in relevant translational animal models prior to human use. This poses a great challenge when the drug is composed of cells, not only because of the living nature of the active ingredient but also due to its human origin, which can subsequently lead to a xenogeneic response in the animals. Although immunosuppression is a plausible solution, this is not suitable for large animals and may also influence the results of the study by altering mechanisms of action that are, in fact, poorly understood. For this reason, a number of procedures have been developed to isolate homologous species-specific cell types to address preclinical pharmacodynamics, pharmacokinetics and toxicology. In this work, we present and discuss advances in the methodologies for derivation of multipotent Mesenchymal Stromal Cells derived from the umbilical cord, in general, and Wharton’s jelly, in particular, from medium to large animals of interest in orthopaedics research, as well as current and potential applications in studies addressing proof of concept and preclinical regulatory aspects.
Open Access
Cell viability evaluation of transdifferentiated endothelial-like cells by quantitative electron-probe X-ray microanalysis for tissue engineering
(Universidad de Murcia. Departamento de Biología Celular e Histología, 2015) Vico, Manuel; Rodríguez-Morata, Alejandro; Garzón, Ingrid; Campos, Fernando; Jaimes Parra, Boris; Pérez-Köhle, Barbara; Buján, Julia; Alaminos, Miguel; Sánchez-Quevedo, Mª Carmen
Development of an efficient vascular substitute by tissue engineering is strongly dependent on endothelial cell viability. The aim of this study was to evaluate cell viability of transdifferentiated endotheliallike cells (Tr-ELC) by using for the first time electron probe X-ray microanalysis (EPXMA), not only to accurately analyze cell viability by quantifying the intracellular ionic concentrations, but also to establish their possible use in vascular tissue engineering protocols. Human umbilical cord Wharton’s jelly stem cells (HWJSC) and endothelial cells from the human umbilical vein (HUVEC) were isolated and cultured. Transdifferentiation from HWJSC to the endothelial phenotype was induced. EPXMA was carried out to analyze HUVEC, HWJSC and Tr-ELC cells by using a scanning electron microscope equipped with an EDAX DX-4 microanalytical system and a solid-state backscattered electron detector. To determine total ion content, the peak-to-local-background (P/B) ratio method was used with reference to standards composed of dextran containing known amounts of inorganic salts. Our results revealed a high K/Na ratio in Tr-ELC (9.41), in association with the maintenance of the intracellular levels of chlorine, phosphorous and magnesium and an increase of calcium (p=0.031) and sulfur (p=0.022) as compared to HWJSC. Calcium levels were similar for HUVEC and Tr-ELC. These results ensure that transdifferentiated cells are highly viable and resemble the phenotypic and microanalytical profile of endothelial cells. Tr-ELC induced from HWJSC may fulfill the requirements for use in tissue engineering protocols applied to the vascular system at the viability and microanalytical levels.
Open Access
Comparison of the effect of cryopreservation protocols on the histology of bioengineered tissues
(Murcia : F. Hernández, 2009) Serrato, Deyanira; Nieto Aguilar, Renato; Garzon, Ingrid; Roda, Olga; Campos, Antonio; Alaminos, Miguel
The purpose of this study was to compare the effects of five different cryopreservation protocols on the histology of bioengineered tissues. Although several artificial tissues have been developed to the date by tissue engineering, classical histological analysis methods and techniques must be optimized for these new tissues with special properties. The results of this study showed that the use of volatile solutions (formaldehyde, glutaraldehyde, glacial acetic acid and acetone) was not able to prevent the formation of large ice crystals that, in turn, can alter the structure of the artificial tissues. However, preincubation of the tissues in different concentrations of a carbon hydrate (glucose, maltose or trehalose) resulted in a better preservation of the tissue structure. We conclude that the best protocol that allows for an efficient analysis of the bioengineered tissues with very few artifacts is preincubation of the tissues in 0.300M or 0.400M trehalose for 30 or 120 min prior to OCT (optimal cutting temperature) embedding and cryosectioning. For all those reasons, we recommend the use of a cryoprotective agent before OCT embedding of human artificial tissues.
Open Access
Engineering vascular grafts from decellularized plants: Advances and challenges
(Universidad de Murcia, Departamento de Histología e Histopatología, 2025) Merna Nick; Biología Celular e Histología
Small-caliber vascular grafts (<6 mm diameter) are critical for coronary and peripheral bypass surgeries, yet developing functional substitutes remains challenging. Autologous vessels are ideal but often unavailable or of poor quality. Synthetic grafts, such as expanded polytetrafluoroethylene (ePTFE) and Dacron, have high failure rates at small diameters due to thrombosis, intimal hyperplasia, and compliance mismatch. Tissue-engineered vascular grafts (TEVGs) aim to overcome these issues by providing a biocompatible scaffold with an endothelial lining. Decellularized plant tissues have recently gained attention as natural scaffolds for TEVGs due to their structural similarity to human vasculature. Leaves and stems provide an extracellular matrix (ECM) primarily composed of cellulose, which is biocompatible, porous, and non-thrombogenic. These scaffolds are cost-effective, scalable, and ethically uncontroversial. Decellularized parsley stems or leatherleaf leaves, for instance, can be recellularized with endothelial and smooth muscle cells (SMCs) to create small-diameter grafts that support endothelialization and withstand physiological pressures. Perfusion bioreactors further enhance the functionality of plant-based grafts by simulating physiological conditions. Pulsatile flow and pressure stimulate endothelial cell alignment, reducing thromb-ogenicity, while mechanical stimulation promotes SMC maturation and ECM deposition, improving graft strength and compliance. This review summarizes recent advances in plant-based vascular grafts and perfusion bioreactor conditioning, compares their performance to conven-tional grafts, and highlights remaining challenges. Decellularized plant scaffolds, with their inherent vascular architecture and biocompatibility, show promise as natural templates for small-caliber vascular grafts. However, further research is needed to address key challenges such as standardization, mechanical optimization, and long-term in vivo validation to facilitate their clinical application
Open Access
Membranes derived from human umbilical cord Wharton's jelly stem cells as novel bioengineered tissue-like constructs
(Universidad de Murcia. Departamento de Biología Celular e Histología, 2018) Jaimes Parra, B.D.; Garzon, I.; Carriel, V.; Durand Herrera, D.; Martín Piedra, M.A.; García, J.M.; Sánchez Quevedo, M.C.; Alaminos, M.; Campos, A.
Cell-derived matrices were recently described as novel biomaterials generated by human cells allowed to grow and synthetize their own extracellular matrix in culture. In the present work, we generated and evaluated a novel tissue-like substitute (WDM) consisting of a membrane derived from cultured human Wharton’s jelly stem cells. WDM were evaluated ex vivo and in vivo by histochemistry and immunohistochemistry for several mesenchymal cell markers and fibrillar and non-fibrillar extracellular matrix components. Results show that WDM were heterogeneous and consisted of dense cell-poor areas surrounded by cell-rich zones with abundant HWJSC. Histological analyses demonstrated that cell-poor areas were very rich in fibrillar and non-fibrillar extracellular matrix components such as collagen and proteoglycans, and cells in the WDM were highly viable and mostly PCNA-positive. HWJSC in the WDM expressed all markers of this cell type, including CD90, CD105, pan cytokeratin and CK8. In vivo analysis showed that the WDM was highly biocompatible and grafting this membrane in the muscle of laboratory rats was not associated to increased inflammation, necrosis, tumorigenesis or other side effects, while cells properly integrated at the damage site and showed high proliferation index. These results suggest that the structure and composition of the extracellular matrix of these novel WDM could reproduce the situation of native human tissues and that WDM implanted in vivo are highly biocompatible and rapidly integrate in the host tissues. For these reasons, we hypothesize that WDM could be used in regenerative medicine protocols.
Open Access
Mesenchymal stem cell - based tissue engineering strategies for repair of articular cartilage
(F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2014) Ahmed, Tamer A.E.; Hincke, Maxwell T.
Restoration of articular cartilage function and structure following pathological or traumatic damage is still considered a challenging problem in the orthopaedic field. Currently, tissue engineering-based reconstruction of articular cartilage is a feasible and continuously developing strategy to restore structure and function. Successful articular cartilage tissue engineering strategy relies largely on several essential components including cellular component, supporting 3D carrier scaffolding matrix, bioactive agents, proper physical stimulants, and safe gene delivery. Designing the right formulations from these components remain the main concern of the orthopaedic community. Utilization of mesenchymal stem cells (MSCs) for articular cartilage tissue engineering is continuously increasing compared to use of chondrocytes. Various sources of MSCs have been investigated including adipose tissue, amniotic fluid, blood, bone marrow, dermis, embryonic stem cells, infrapatellar fat pad, muscle, periosteum, placenta, synovium, trabecular bone, and umbilical cord. MSCs derived from bone marrow and umbilical cord are currently in different phases of clinical trials. A wide range of matrices have been investigated to develop tissue engineering - based strategies including carbohydrate-based scaffolds (agarose, alginate, chitosan/chitin, and hyaluronate), protein-based scaffolds (collagen, fibrin, and gelatin), and artificial polymers (polyglycolic acid, polylactic acid, poly(lacticco-glycolic acid), polyethylene glycol, and polycaprolactone). Collagen - based scaffolds and photopolymerizable PEG - based scaffolds are currently in different phases of clinical trials. TGF-ß1, TGF-ß3, BMP-2, and hypoxic environment are the recommended bioactive agents to induce optimum chondrogenesis of MSCs, while TGF-ß1, TGF-ß3, SOX-9, BMP-2, and BMP-7 genes are the best candidate for gene delivery to MSCs. Electromagnetic field and the combination of shear forces/dynamic compression are the best maturation-promoting physical stimulants.
Open Access
Mesenchymal stem cell-mediated treatment of oral diseases
(F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2014) Liu, Yi; Hu, Jingchao; Wang, Songlin
In the oral maxillofacial region, there are significant demands for repairing severe tissue defects caused by congenital malformations, oncologic resection, post-traumatic loss, and pathologic degenerative destruction such as periodontitis. Mesenchymal stem cells (MSCs) are adult stem cells whose multipotency has been investigated for therapeutic applications. This review highlights the main MSCs involved in the tissue regeneration of oral maxillofacial region and recent advances in dental MSCbased tissue regeneration and treatments in this region. MSCs isolated from oral maxillofacial sources have higher proliferation rates and are more capable of forming bone and dental tissues. Large animal models of oral diseases or defects were established and treated with MSCs. Miniature pigs or dogs more closely mimic disease in humans and provide a useful means for translating research into clinical applications. MSCs exert other beneficial effects, including immunomodulation and paracrine processes. The immunoregulatory properties of MSCs facilitate their application to oral diseases and tissue regeneration. Besides autologous MSCs being an excellent cell source for tissue engineering and regenerative medicine, allogeneic MSC-based treatment also provides a safe and effective therapeutic modality, the use of allogeneic MSCs in highly standardized clinical trials could lead to a better understanding of their real-life applications, which sheds light on potential clinical applications for treating oral diseases.
Open Access
Muscle-derived stem cells in tissue engineering: defining cell properties suitable for construct design
(Murcia : F. Hernández, 2005) Buján, J.; Pascual, G.; Corrales, C.; Gómez-Gil, V.; Rodríguez, M.; Bellón, J.M.
The terms construct or tissue equivalent refer to neotissue produced by tissue engineering techniques. The elements forming the construct are scaffolds on which cells are “recreated” to form an enginnered-tissue sensitive to certain cell signals. The ability of the cells to expand and differentiate on the scaffold is determined by properties such as fixation, adhesion, proliferation and migration. Among the cell types that seem to be most promising for designing constructs are tissue-residing, or adult, stem cells, which show two main features: a capacity to differentiate into many cell lineages and the power of self-renewal. These features make them good candidates for cell replacement therapies. Here, we report the identification, isolation and culture of muscle stem cells aimed at establishing the ideal culture in terms of defining when the cultured cell population would show optimal characteristics for transfer to the scaffold to obtain a particular construct. Stem cells harvested from the dorsal muscle of white New Zealand rabbits were cultured in vitro and characterized 5 to 14 days after the start of culture. Fibroblasts obtained from the same experimental animal served as controls. The stem cells were examined by light and scanning electron microscopy. For stem cell identification, we used the antibodies anti-m-cadherin, anti-CD34 and anti-Myf-5. The markers of muscle differentiation used were: antivimentin, anti-a-actin, anti-desmin and anti-myosin. The expression profiles of the different markers of muscle differentiation and TGFß1 in the cell cultures were confirmed by Western blotting. Proliferation rates were determined by monitoring tritiated thymidine incorporation. The thymidine incorporation rate was substantially higher for the population of undifferentiated cells than for control fibroblasts obtained from the same animal. During the first five days of culture, most cells were negative for all the markers examined, with the exception of m-cadherin, CD34 and Myf-5, although discrete signs of vimentin expression started to emerge. After 14 days of culture, the adult stem cells showed vimentin (94.2%) and desmin (33.8%) expression yet scarce labeling for myosin (16.2%) and a-actin (8.3%). Control fibroblasts showed intense labeling for vimentin (99.3%) and a-actin (62.2%), while less than 2% of the population expressed myosin (0.9%) and desmin (1.6%). After two weeks of culture, muscle-derived stem cells show good proliferative and adhesion properties as they initiate differentiation. These conditions seem ideal for obtaining the desired construct.
Open Access
Small molecule GSK-3 antagonists play a pivotal role in reducing the local inflammatory response, in promoting resident stem cell activation and in improving tissue repairing in regenerative dentistry
(Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2019) Tatullo, Marco; Makeeva, Irina; Rengo, Sandro; Rengo, Carlo; Spagnuolo, Gianrico; Codispoti, Bruna
Regenerative dentistry is attracting growing interest in the scientific community, mainly because of its translational and promising therapeutic approach. The latest research carried out by the scientific community are aimed at triggering the local cellular response, in order to induce a physiological self- repairing of damaged oral tissues. Such physiological processes mainly involve the activation of local stem cell populations: mesenchymal stem cells, in fact, retain the ability to proliferate and to differentiate towards functional mature elements, thus leading towards healing of damaged tissues. Glycogen Synthase Kinase-3 (GSK-3) is a key- regulator of the Wnt/β-catenin pathway; it phosphorylates β-catenin, that then is degraded in the cytosol. The activation of such signalling, mediated by Wnt ligand/receptor association, inhibits GSK-3, leading to translocation of β-catenin to the nucleus and to gene transcription. Selective inhibitors of GSK-3 have been linked to the activity of Wnt signalling and to the regeneration of injured tissues, including complex dental and oral structures. Small Molecule GSK-3 Antagonists are the most interesting class of molecules acting with a "Bystander effect": reducing local inflammation and local bone resorption and triggering the activity and differentiation of resident "sleeping" MSCs. The aim of this narrative topical review is to describe the current knowledge on the role of small molecule GSK-3 antagonists in regenerative dentistry, with strategic insights towards the translational applications in nanomaterials in dentistry and in dental repairing.
Open Access
Tissue-engineered biological dressing accelerates skin wound healing in mice via formation of provisional connective tissue
(Universidad de Murcia. Departamento de Biología Celular e Histología, 2018) Chermnykh, Elina S.; Kiseleva, Ekaterina V.; Rogovaya, Olga S.; Rippa, Aleksandra L.; Vasiliev, Andrey V.; Vorotelyak, Ekaterina A.
Despite recent advances in bioengineered therapies, wound healing remains a serious clinical problem. In acute full-thickness wounds, it is desirable to replace both the damaged dermis and epidermis in a single procedure. This approach requires appropriate properties of tissue-engineered dressings to support simultaneous regenerative processes in the dermis and epidermis while they are temporally separated in the natural wound healing process. In this study, a collagen-based scaffold inhabited by skin cells was employed. Its ability to stimulate the skin repair of full-thickness excisional splinting wounds in a murine model was evaluated in comparison with that of acellular collagen and commercially available gelatin porous sponge Spongostan®. The study showed that cell-based skin equivalent promoted the immediate filling of the wound bed and provided simultaneous reorganization of the dermal component into highly vascularized granulation-like tissue and rapid epithelialization, thus improving the quality of healing. Inflammation was delayed and less pronounced. In contrast, acellular collagen and especially Spongostan® failed to demonstrate similar results. The porous structure of Spongostan® prevented effective long-term epithelialization and impeded the formation of an adequate connective tissue at the wound bed.
Open Access
Use of nanoparticles in skeletal tissue regeneration and engineering
(Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2020) Filippi, Miriam; Born, Gordian; Flesch, Delphine Felder; Scherberich, Arnaud
Bone and osteochondral defects represent one of the major causes of disabilities in the world. Derived from traumas and degenerative pathologies, these lesions cause severe pain, joint deformity, and loss of joint motion. The standard treatments in clinical practice present several limitations. By producing functional substitutes for damaged tissues, tissue engineering has emerged as an alternative in the treatment of defects in the skeletal system. Despite promising preliminary clinical outcomes, several limitations remain. Nanotechnologies could offer new solutions to overcome those limitations, generating materials more closely mimicking the structures present in naturally occurring systems. Nanostructures comparable in size to those appearing in natural bone and cartilage have thus become relevant in skeletal tissue engineering. In particular, nanoparticles allow for a unique combination of approaches (e.g. cell labelling, scaffold modification or drug and gene delivery) inside single integrated systems for optimized tissue regeneration. In the present review, the main types of nanoparticles and the current strategies for their application to skeletal tissue engineering are described. The collection of studies herein considered confirms that advanced nanomaterials will be determinant in the design of regenerative therapeutic protocols for skeletal lesions in the future.

Browsing by Subject "Tissue engineering"

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