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1.
Nat Rev Urol ; 17(3): 162-175, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32024995

RESUMO

Hypospadias is a congenital malformation resulting from the disruption of normal urethral formation with varying global prevalence. Hypospadias repair, especially that of proximal hypospadias (in which reconstruction of a long urethra is necessary), remains a surgical challenge despite more than two decades of surgical technique development and refinement. The lack of tissue substitutes with mechanical and biological properties similar to those of native urethra is a challenge for which the field of tissue engineering might offer promising solutions. However, the use of tissue-engineered constructs in preclinical studies is still hindered by complications such as strictures or fistulae, which have slowed progression to clinical application. Furthermore, the generation of uniform tubular constructs remains a challenge. Exciting advances in the application of nanotechnology and 3D bioprinting to urethral tissue engineering might present solutions to these issues.


Assuntos
Hipospadia/terapia , Engenharia Tecidual/métodos , Procedimentos Cirúrgicos Urológicos Masculinos/métodos , Algoritmos , Animais , Ensaios Clínicos como Assunto , Humanos , Hipospadia/classificação , Masculino , Procedimentos Cirúrgicos Reconstrutivos , Transplante de Células-Tronco , Uretra/cirurgia
2.
Plast Reconstr Surg ; 145(2): 337e-347e, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31985634

RESUMO

BACKGROUND: Three-dimensionally-printed bioceramic scaffolds composed of ß-tricalcium phosphate delivering the osteogenic agent dipyridamole can heal critically sized calvarial defects in skeletally mature translational models. However, this construct has yet to be applied to growing craniofacial models. In this study, the authors implanted three-dimensionally-printed bioceramic/dipyridamole scaffolds in a growing calvaria animal model and evaluated bone growth as a function of geometric scaffold design and dipyridamole concentration. Potential adverse effects on the growing suture were also evaluated. METHODS: Bilateral calvarial defects (10 mm) were created in 5-week-old (approximately 1.1 kg) New Zealand White rabbits (n = 16 analyzed). Three-dimensionally-printed bioceramic scaffolds were constructed in quadrant form composed of varying pore dimensions (220, 330, and 500 µm). Each scaffold was coated with collagen and soaked in varying concentrations of dipyridamole (100, 1000, and 10,000 µM). Controls consisted of empty defects. Animals were killed 8 weeks postoperatively. Calvariae were analyzed using micro-computed tomography, three-dimensional reconstruction, and nondecalcified histologic sectioning. RESULTS: Scaffold-induced bone growth was statistically greater than bone growth in empty defects (p = 0.02). Large scaffold pores, 500 µm, coated in 1000 µM dipyridamole yielded the most bone growth and lowest degree of scaffold presence within the defect. Histology showed vascularized woven and lamellar bone along with initial formation of vascular canals within the scaffold lattice. Micro-computed tomographic and histologic analysis revealed patent calvarial sutures without evidence of ectopic bone formation across all dipyridamole concentrations. CONCLUSION: The authors present an effective pediatric bone tissue-engineering scaffold design and dipyridamole concentration that is effective in augmentation of calvarial bone generation while preserving cranial suture patency.


Assuntos
Regeneração Óssea/efeitos dos fármacos , Fosfatos de Cálcio/uso terapêutico , Dipiridamol/uso terapêutico , Fraturas Cranianas/cirurgia , Engenharia Tecidual/métodos , Tecidos Suporte , Animais , Dipiridamol/administração & dosagem , Modelos Animais de Doenças , Coelhos , Crânio/efeitos dos fármacos , Crânio/lesões , Fraturas Cranianas/tratamento farmacológico
3.
Life Sci ; 240: 117066, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31738881

RESUMO

Tissue engineering and the use of scaffolds have shown high therapeutic potentialities about male and female infertility. Nowadays, many couples are suffering from infertility problems. There are different causes for infertility including chemotherapy (for male and female), uterine injuries, and intrauterine adhesions. Extra-cellular matrix in tissue engineering provides a supportive medium for blood or lymphatic vessels making it a suitable substrate for cell implantation and growth. Dominant successes in this branch have been in use of patient-derived primary cells, these cells loaded in scaffolds and used to generate tissue for re-implantation. However, this method has limitations, because of the invasive nature of cell collection, also the cells patient-derived may be not healthy and become the source of disease. Therefore, use of stem cells, including embryonic stem (ES) cells, bone marrow mesenchymal stem cells (BM-MSCs) and umbilical cord-derived mesenchymal stem cells (UC-MSCs) have been considered. Cell/scaffold systems have a substantial role in fertility organs or agents repair or regeneration. This review summarizes the novel scaffold-based tissue engineering approaches to treat infertility.


Assuntos
Infertilidade Feminina/terapia , Infertilidade Masculina/terapia , Engenharia Tecidual/métodos , Tecidos Suporte , Animais , Feminino , Humanos , Masculino , Transplante de Células-Tronco Mesenquimais , Gravidez , Transplante de Células-Tronco
4.
J Orthop Res ; 38(2): 438-449, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31529713

RESUMO

The nucleus pulposus (NP) is composed of NP and notochord cell. It is a paucicellular tissue and if it is to be used as a source of cells for tissue engineering the cell number will have to be expanded by cell passaging. The hypothesis of this study is that passaged NP and notochordal cells grown in three-dimensional (3D) culture in the presence of transforming growth factor ß (TGFß) will show enhanced NP tissue formation compared with cells grown in the absence of this growth factor. Bovine NP cells isolated by sequential enzymatic digestion from caudal intervertebral discs were either placed directly in 3D culture (P0) or serially passaged up to passage 3 (P3) prior to placement in 3D culture. Serial cell passage in monolayer culture led to de-differentiation, increased senescence and oxidative stress and decreases in the gene expression of NP and notochordal associated markers and increases in de-differentiation markers. The NP tissue regeneration capacity of cells in 3D culture decreases with passaging as indicated by diminished tissue thickness and total collagen content when compared with tissues formed by P0 cells. Immunohistochemical studies showed that type II collagen accumulation appeared to decrease. TGFß1 or TGFß3 treatment enhanced the ability of cells at each passage to form tissue, in part by decreasing cell death. However, neither TGFß1 nor TGFß3 were able to restore the notochordal phenotype. Although TGFß1/3 recovered NP tissue formation by passaged cells, to generate NP in vitro that resembles the native tissue will require identification of conditions facilitating retention of notochordal cell differentiation. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:438-449, 2020.


Assuntos
Notocorda/citologia , Núcleo Pulposo/citologia , Engenharia Tecidual/métodos , Fator de Crescimento Transformador beta1 , Fator de Crescimento Transformador beta3 , Animais , Bovinos , Senescência Celular , Estresse Oxidativo , Cultura Primária de Células
5.
J Vasc Access ; 21(1): 110-115, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31169047

RESUMO

This study presents the initial 3-year results of the first in-human study of internal shunt restoration using completely autologous vascular grafts, "Biotubes," based on in-body tissue architecture. Biotubes (diameter, 6 mm; length, 7 cm) were prepared as autologous collagenous tubular tissues with approximately 0.5 mm wall thickness by embedding molds (two per patient), assembled with a silicone rod and a stainless steel pipe with many slits, into the patients' abdominal subcutaneous tissue for 2 months. Two female patients with end-stage renal disease were undergoing hemodialysis with a high probability of failure due to repeated stenosis every few months at the venous outflow regions over 1.5 years. Biotubes formed in both patients and were bypassed over the venous stenosis region of the arteriovenous shunt. After bypass with Biotubes without living cells, palpable thrill and typical turbulent flow pattern were observed by pulsed-wave Doppler. Follow-up angiography showed no signs of dilation or stenosis after implantation, and puncture could be performed easily without graft damage. In both cases, stenosis of Biotubes occurred after 3-4 months. In the first case, percutaneous transluminal angioplasty was not required for over 2 years after implantation even after the development of Biotube stenosis. In the second case, stenosis at the proximal anastomotic site of the Biotube became prominent, and percutaneous transluminal angioplasty was needed 7 months after implantation and then repeated at up to 2 years. This was the first human study successfully supporting the concept of internal shunt restoration for hemodialysis using an autologous Biotube.


Assuntos
Derivação Arteriovenosa Cirúrgica/instrumentação , Bioprótese , Implante de Prótese Vascular/instrumentação , Prótese Vascular , Falência Renal Crônica/terapia , Engenharia Tecidual/métodos , Feminino , Humanos , Falência Renal Crônica/diagnóstico , Pessoa de Meia-Idade , Desenho de Prótese , Diálise Renal , Resultado do Tratamento , Grau de Desobstrução Vascular
6.
Adv Exp Med Biol ; 1212: 57-70, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-30989589

RESUMO

Decellularized tissues are gaining popularity as scaffolds for tissue engineering; they allow cell attachment, proliferation, differentiation, and are non-immunogenic. Adipose tissue is an abundant resource that can be decellularized and converted in to a bio-scaffold. Several methods have been developed for adipose tissue decellularization, typically starting with freeze thaw cycles, followed by washes with hypotonic/hypertonic sodium chloride solution, isopropanol, detergent (SDS, SDC and Triton X-100) and trypsin digestion. After decellularization, decellularized adipose tissue (DAT) can be converted into a powder, solution, foam, or sheet to allow for convenient subcutaneous implantation or to repair external injuries. Additionally, DAT bio-ink can be used to 3D print structures that closely resemble physiological tissues and organs. Proteomic analysis of DAT reveals that it is composed of collagens (I, III, IV, VI and VII), glycosaminoglycans, laminin, elastin, and fibronectin. It has also been found to retain growth factors like VEGF and bFGF after decellularization. DAT inherently promotes adipogenesis when seeded with adipose stem cells in vitro, and when DAT is implanted subcutaneously it is capable of recruiting host stem cells and forming adipose tissue in rodents. Furthermore, DAT has promoted healing in rat models of full-thickness skin wounds and peripheral nerve injury. These findings suggest that DAT is a promising candidate for repair of soft tissue defects, and is suitable for breast reconstruction post-mastectomy, wound healing, and adipose tissue regeneration. Moreover, since DAT's form and stiffness can be altered by physicochemical manipulation, it may prove suitable for engineering of additional soft and hard tissues.


Assuntos
Tecido Adiposo/química , Proteômica , Engenharia Tecidual/métodos , Tecidos Suporte/química , Tecido Adiposo/citologia , Animais , Humanos , Mastectomia/métodos
7.
Adv Exp Med Biol ; 1212: 71-85, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-30707350

RESUMO

Decellularized organs and tissues are effectively utilized in a diversity of regenerative medicine purposes, and the decellularization approaches employed differ as broadly as the tissues/organs of concern. Biological scaffold substances formed by extracellular matrix (ECM) are mostly produced with methods that include decellularization of tissues. Conservation of the multifaceted arrangement and three-dimensional (3D) construction of the ECM is very wanted but it is documented that almost every approach of decellularization cause disturbance of the organization and possible forfeiture of surface organization and conformation. The competence of cell elimination from a tissue is reliant on the basis of the tissue and the precise physical, chemical, and enzymatic approaches that are utilized. Here, the most frequently applied and newly developed decellularization techniques are designated, organ engineering with decellularized scaffolds for different organs, recent knowledge in the field are explained.


Assuntos
Medicina Regenerativa , Engenharia Tecidual/métodos , Tecidos Suporte , Matriz Extracelular , Humanos , Medicina Regenerativa/métodos
8.
Rozhl Chir ; 98(10): 388-393, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31842567

RESUMO

Repopulation of decellularized tissue with cells is a very promising approach in tissue engineering, with liver tissue engineering not being an exception. Decellularized liver scaffolds can serve as an excellent 3D environment for recellularization as it maintain tissue-specific microarchitecture of ECM proteins with important spatial cues for cell adhesion, migration, growth and differentiation. Moreover, by using autologous cells the newly constructed graft should lack immunogenicity in the host organism and thus eliminate the need for immunosuppressive therapy in the post-transplant period. This review provides an overview of liver decellularization and repopulation experiments done so far while highlighting the advances as well as pin-pointing the challenges that remain to be solved.


Assuntos
Fígado/fisiologia , Engenharia Tecidual/métodos , Tecidos Suporte , Animais , Fenômenos Fisiológicos Celulares , Matriz Extracelular/fisiologia , Humanos , Fígado/citologia , Suínos
9.
Pharm Res ; 37(1): 8, 2019 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-31848830

RESUMO

PURPOSE: Microphysiological systems (MPS), also known as "organs-on-chips" or "tissue chips," leverage recent advances in cell biology, tissue engineering, and microfabrication to create in vitro models of human organs and tissues. These systems offer promising solutions for modeling human physiology and disease in vitro and have multiple applications in areas where traditional cell culture and animal models fall short. Recently, the National Center for Advancing Translational Sciences (NCATS) at the National Institutes of Health (NIH) and the International Space Station (ISS) U.S. National Laboratory have coordinated efforts to facilitate the launch and use of these MPS platforms onboard the ISS. Here, we provide an introduction to the NIH Tissue Chips in Space initiative and an overview of the coordinated efforts between NIH and the ISS National Laboratory. We also highlight the current progress in addressing the scientific and technical challenges encountered in the development of these ambitious projects. Finally, we describe the potential impact of the Tissue Chips in Space program for the MPS field as well as the wider biomedical and health research communities.


Assuntos
Engenharia Tecidual/métodos , Ausência de Peso , Animais , Humanos , Microfluídica , Voo Espacial , Estados Unidos
10.
Int J Nanomedicine ; 14: 6615-6630, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31695360

RESUMO

Background: Nanocomposites produced by reinforcement of polysaccharide matrix with nanoparticles are widely used in engineering of biomaterials. However, clinical applications of developed novel biomaterials are often limited due to their poor biocompatibility. Purpose: The aim of this work was to comprehensively assess biocompatibility of highly macroporous chitosan/agarose/nanohydroxyapatite bone scaffolds produced by a novel method combining freeze-drying with a foaming agent. Within these studies, blood plasma protein adsorption, osteoblast (MC3T3-E1 Subclone 4 and hFOB 1.19) adhesion and proliferation, and osteogenic differentiation of mesenchymal stem cells derived from bone marrow and adipose tissue were determined. The obtained results were also correlated with materials' surface chemistry and wettability to explain the observed protein and cellular response. Results: Obtained results clearly showed that the developed nanocomposite scaffolds were characterized by high biocompatibility and osteoconductivity. Importantly, the scaffolds also revealed osteoinductive properties since they have the ability to induce osteogenic differentiation (Runx2 synthesis) in undifferentiated mesenchymal stem cells. The surface of biomaterials is extremely hydrophilic, prone to protein adsorption with the highest affinity toward fibronectin binding, which allows for good osteoblast adhesion, spreading, and proliferation. Conclusion: Produced by a novel method, macroporous nanocomposite biomaterials have great potential to be used in regenerative medicine for acceleration of the bone healing process.


Assuntos
Regeneração Óssea , Osso e Ossos/fisiologia , Quitosana/química , Durapatita/química , Nanocompostos/química , Osteoblastos/citologia , Sefarose/química , Engenharia Tecidual/métodos , Tecidos Suporte/química , Adsorção , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Biomarcadores/metabolismo , Regeneração Óssea/efeitos dos fármacos , Osso e Ossos/efeitos dos fármacos , Adesão Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Cães , Feminino , Humanos , Células-Tronco Mesenquimais/citologia , Camundongos , Osteogênese/efeitos dos fármacos , Molhabilidade
11.
Eur J Histochem ; 63(3)2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31696691

RESUMO

Recently, the development and the application of 3D scaffold able to promote stem cell differentiation represented an essential field of interest in regenerative medicine. In particular, functionalized scaffolds improve bone tissue formation and promote bone defects repair. This research aims to evaluate the role of ascorbic acid (AS) supplementation in an in vitro model, in which a novel 3D-scaffold, bovine pericardium collagen membrane called BioRipar (BioR) was functionalized with human Gingival Mesenchymal Stem Cells (hGMSCs). As extensively reported in the literature, AS is an essential antioxidant molecule involved in the extracellular matrix secretion and in the osteogenic induction. Specifically, hGMSCs were seeded on BioR and treated with 60 and 90 µg/mL of AS in order to assess their growth behavior, the expression of bone specific markers involved in osteogenesis (runt-related transcription factor 2, RUNX2; collagen1A1, COL1A1; osteopontin, OPN; bone morphogenetic protein2/4, BMP2/4), and de novo deposition of calcium. The expression of COL1A1, RUNX2, BMP2/4 and OPN was evaluated by RT-PCR, Western blotting and immunocytochemistry, and proved to be upregulated. Our results demonstrate that after three weeks of treatment AS at 60 and 90 µg/mL operates as an osteogenic inductor in hGMSCs. These data indicate that the AS supplementation produces an enhancement of osteogenic phenotype commitment in an in vitro environment. For this reason, AS could represent a valid support for basic and translational research in tissue engineering and regenerative medicine.


Assuntos
Ácido Ascórbico/metabolismo , Colágeno Tipo I/metabolismo , Células-Tronco Mesenquimais/metabolismo , Pericárdio/metabolismo , Tecidos Suporte/química , Animais , Biomarcadores/metabolismo , Proteína Morfogenética Óssea 2/metabolismo , Proteína Morfogenética Óssea 4/metabolismo , Bovinos , Diferenciação Celular/fisiologia , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Gengiva/metabolismo , Humanos , Osteogênese/fisiologia , Osteopontina/metabolismo , Pericárdio/citologia , Medicina Regenerativa/métodos , Engenharia Tecidual/métodos
12.
Pharm Res ; 36(12): 183, 2019 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-31741058

RESUMO

Research conducted in microgravity conditions has the potential to yield new therapeutics, as advances can be achieved in the absence of phenomena such as sedimentation, hydrostatic pressure and thermally-induced convection. The outcomes of such studies can significantly contribute to many scientific and technological fields, including drug discovery. This article reviews the existing traditional microgravity platforms as well as emerging ideas for enabling microgravity research focusing on SpacePharma's innovative autonomous remote-controlled microgravity labs that can be launched to space aboard nanosatellites to perform drug research in orbit. The scientific literature is reviewed and examples of life science fields that have benefited from studies in microgravity conditions are given. These include the use of microgravity environment for chemical applications (protein crystallization, drug polymorphism, self-assembly of biomolecules), pharmaceutical studies (microencapsulation, drug delivery systems, behavior and stability of colloidal formulations, antibiotic drug resistance), and biological research, including accelerated models for aging, investigation of bacterial virulence , tissue engineering using organ-on-chips in space, enhanced stem cells proliferation and differentiation.


Assuntos
Simulação de Ausência de Peso/instrumentação , Simulação de Ausência de Peso/métodos , Ausência de Peso , Fatores Etários , Diferenciação Celular , Linhagem Celular , Proliferação de Células , Cristalização/instrumentação , Cristalização/métodos , Dimerização , Composição de Medicamentos/instrumentação , Composição de Medicamentos/métodos , Sistemas de Liberação de Medicamentos/instrumentação , Sistemas de Liberação de Medicamentos/métodos , Descoberta de Drogas/instrumentação , Descoberta de Drogas/métodos , Resistência Microbiana a Medicamentos , Humanos , Microfluídica/instrumentação , Microfluídica/métodos , Pesquisa Farmacêutica/instrumentação , Pesquisa Farmacêutica/métodos , Fenômenos Físicos , Proteínas/química , Voo Espacial , Engenharia Tecidual/instrumentação , Engenharia Tecidual/métodos
13.
Life Sci ; 239: 117070, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31751580

RESUMO

Doxorubicin (DOX) induced cardiotoxicity is a life-threatening side effect of chemotherapy and decreased cardiac function can present years after treatment. Despite the investigation of a broad range of pharmacologic interventions, to date the only drug shown to reduce DOX-related cardiotoxicity in preclinical studies and limited clinical trials is the iron chelating agent, dexrazoxane (DRZ), although the mechanisms responsible for DRZ mediated protection from DOX related cardiotoxicity remain unclear. Engineered cardiac tissues (ECTs) can be used for tissue repair strategies and as in vitro surrogate models to test cardiac toxicities and preventative countermeasures. Neonatal murine ECTs display cardiotoxicity in response to the environmental toxin, cadmium, and reduced cadmium toxicity with Zinc co-treatment, in part via the induction of the anti-oxidant Metallothionein (MT). We adapted our in vitro ECT model to determine the feasibility of using the ECT approach to investigate DOX-related cardiac injury and DRZ prevention. We found: (1) DOX induced dose and time dependent cell death in ECTs; (2) Zinc did not show protection from DOX cardiotoxicity; (3) MT overexpression induced by Zinc, low dose Cd pretreatment, or MT-overexpression (MT-TG) did not reduce ECT DOX cardiotoxicity; (4) DRZ reduced ECT DOX induced cell death; and (5) The mechanism of DRZ ECT protection from DOX cardiotoxicity was topoisomerase 2B (TOP2B) inhibition rather than reduced reactive oxygen species. Our data support the feasibility of ECTs as an in vitro platform technology for the investigation of drug induced cardiotoxicities including the role of TOP2B in DOX toxicity and DRZ mediated DOX toxicity prevention.


Assuntos
Cardiotoxicidade/metabolismo , Dexrazoxano/farmacologia , Miócitos Cardíacos/metabolismo , Animais , Animais Recém-Nascidos , Cardiotoxicidade/prevenção & controle , DNA Topoisomerases Tipo II/metabolismo , Dexrazoxano/metabolismo , Modelos Animais de Doenças , Doxorrubicina/toxicidade , Quelantes de Ferro/farmacologia , Metalotioneína/metabolismo , Camundongos , Camundongos Transgênicos , Miócitos Cardíacos/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Engenharia Tecidual/métodos
14.
Chem Asian J ; 14(24): 4837-4846, 2019 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-31756283

RESUMO

Three-dimensional (3D) scaffolds formed from natural biopolymers gelatin and chitosan that are chemically modified by galactose have shown improved hepatocyte adhesion, spheroid geometry and functions of the hepatocytes. Galactose specifically binds to the hepatocytes via the asialoglycoprotein receptor (ASGPR) and an increase in galactose density further improves the hepatocyte proliferation and functions. In this work, we aimed to increase the galactose density within the biopolymeric scaffold by physically blending the biopolymers chitosan and gelatin with an amphiphlic ß-galactose polypeptide (PPO-GP). PPO-GP, is a di-block copolymer with PPO and ß-galactose polypeptide, exhibits lower critical solution temperature and is entrapped within the scaffold through hydrophobic interactions. The uniform distribution of PPO-GP within the scaffold was confirmed by fluorescence microscopy. SEM and mechanical testing of the hybrid scaffolds indicated pore size, inter connectivity and compression modulus similar to the scaffolds made from 100 % biopolymer. The presence of the PPO-GP on the surface of the scaffold was tested monitoring the interaction of an analogous mannose containing PPO-GP scaffold and the mannose binding lectin Con-A. In vitro cell culture experiments with HepG2 cells were performed on GLN-GP and CTS-GP and their cellular response was compared with GLN and CTS scaffolds for a period of seven days. Within three days of culture the Hep G2 cells formed multicellular spheroids on GLN-GP and CTS-GP more efficiently than on the GLN and CTS scaffolds. The multicellular spheroids were also found to infiltrate more in GLN-GP and CTS-GP scaffolds and able to maintain their round morphology as observed by live/dead and SEM imaging.


Assuntos
Quitosana/química , Gelatina/química , Glicoproteínas/química , Hepatócitos/metabolismo , Polímeros/química , Propilenoglicóis/química , Tecidos Suporte/química , Animais , Módulo de Elasticidade , Galactosídeos/química , Células Hep G2 , Humanos , Hidrogéis/síntese química , Hidrogéis/química , Esferoides Celulares/metabolismo , Suínos , Engenharia Tecidual/métodos
15.
Nat Protoc ; 14(12): 3395-3425, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31705125

RESUMO

The extracellular matrix (ECM) is a major regulator of homeostasis and disease, yet the 3D structure of the ECM remains poorly understood because of limitations in ECM visualization. We recently developed an ECM-specialized method termed in situ decellularization of tissues (ISDoT) to isolate native 3D ECM scaffolds from whole organs in which ECM structure and composition are preserved. Here, we present detailed surgical instructions to facilitate decellularization of 33 different mouse tissues and details of validated antibodies that enable the visualization of 35 mouse ECM proteins. Through mapping of these ECM proteins, the structure of the ECM can be determined and tissue structures visualized in detail. In this study, perfusion decellularization is presented for bones, skeletal muscle, tongue, salivary glands, stomach, duodenum, jejunum/ileum, large intestines, mesentery, liver, gallbladder, pancreas, trachea, bronchi, lungs, kidneys, urinary bladder, ovaries, uterine horn, cervix, adrenal gland, heart, arteries, veins, capillaries, lymph nodes, spleen, peripheral nerves, eye, outer ear, mammary glands, skin, and subcutaneous tissue. Decellularization, immunostaining, and imaging take 4-5 d.


Assuntos
Matriz Extracelular/metabolismo , Imagem Tridimensional/métodos , Coloração e Rotulagem/métodos , Animais , Anticorpos/metabolismo , Matriz Extracelular/fisiologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Especificidade de Órgãos , Perfusão/métodos , Engenharia Tecidual/métodos , Tecidos Suporte/química
16.
S Afr Med J ; 109(8b): 34-39, 2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31662147

RESUMO

Bioprinting advances have revolutionised drug discovery and are set to disrupt biomedical research and medical application through the development of reproducible, fine-tuned functional 3D tissues and, eventually, whole organs. This intersectional bottom-up approach of additive manufacturing requires collaboration between tissue engineers, materials chemists, software and electrical engineers and medical practitioners for the software, hardware and wetware required by this disruptive technology. This review provides a current overview of the state of the art of bioprinting and the biomaterials/bioinks required, as well as the challenges and prospects for medical application in South Africa.


Assuntos
Bioimpressão/métodos , Impressão Tridimensional , Pesquisa Biomédica/métodos , Comportamento Cooperativo , Descoberta de Drogas/métodos , Humanos , África do Sul , Engenharia Tecidual/métodos
17.
J Physiol Pharmacol ; 70(3)2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31566194

RESUMO

Pelvic organ disorders affect up to one in four women in the United States. The prevalence of pelvic organ prolapse (POP) is increasing with each year, particularly in the setting of prolonged life expectancy and an aging population. Current treatment approaches, including polypropylene monofilaments are associated with numerous painful and worrisome side-effects. Therefore, scientists are looking for new solutions. A promising alternative to the current treatment is tissue engineering, which can be utilized to re-create support to the vagina and pelvic organs. Tissue engineering requires the use of three-dimensional scaffolds, derived from biocompatible materials. Chitosan is a natural polymer, obtained from shellfish exoskeletons. It is known for its biodegradability, lack of cytotoxicity and non-pyrogenicity. Due to the presence of free hydroxyl and amino groups, it may undergo various modifications. In this paper, we describe a new type of chitosan-based biomaterials, which can be used as a new alternative scaffold that may provide support to prolapse organs. The chitosan scaffold was obtained under microwave radiation using multifunctional amino and organic acids. We discuss the scaffold's characteristics, with an emphasis on its chemical structure and morphology. Fourier transform infrared spectroscopy (FT-IR) analysis confirmed cross-linking processes with preservation of free amino groups. Moreover, mechanical durability, the stability and swelling ability of the scaffolds in a simulated body fluid were investigated. All of the prepared scaffolds demonstrated very good antioxidant activity and biodegradability. Importantly, the biocompatibility of chitosan scaffolds was examined on human vaginal VK2/E6E7 cell line. No evidence of toxicity was documented, and the cells maintained their presence on the studied materials. These results allude to the lack of toxicity of the scaffolds, and indicate that chitosan-based scaffold should be further investigated in in vivo studies as they may be a promising alternative treatment to pelvic organ prolapse.


Assuntos
Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Quitosana/química , Prolapso de Órgão Pélvico/tratamento farmacológico , Antioxidantes/química , Antioxidantes/farmacologia , Linhagem Celular , Humanos , Micro-Ondas , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Engenharia Tecidual/métodos
18.
Tissue Cell ; 60: 25-32, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31582015

RESUMO

Due to morbidity and mortality of cardiovascular diseases around the globe, there has been an unmet clinical need for small caliber vascular grafts. Autologous vessels are still the gold standard for small caliber vascular grafts (<6 mm). In an attempt to develop a tissue-engineered vascular graft, several approaches have been pursued. One of the promising techniques is the use of acellular matrices offering a prospect of being able to meet the demand for small caliber vessels. Acellular matrices can ideally preserve the vascular wall complexity, biochemical properties, and bioactivity required for tissue regeneration and function. Various strategies have emerged to increase long term patency of acellular matrices including surface modification and pre-implantation cell seeding. This article reviews the most recent and relevant in vivo studies on acellular small caliber vascular grafts, which provides an outlook toward the preclinical potential of acellular extracellular matrices in vascular tissue engineering.


Assuntos
Prótese Vascular , Engenharia Tecidual/métodos , Animais , Matriz Extracelular , Humanos
19.
Carbohydr Polym ; 226: 115284, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31582083

RESUMO

Cellulose based microcarriers can be used in biomedical science as supports for cell adhesion and proliferation. However, to facilitate cell attachment to their surface, they require appropriate functional surface charge. Cell function such as adhesion and growth is increased on the modified surfaces with cationic and anionic groups. In this research, diethylaminoethyl cellulose was carboxymethylated to produce soluble multifunctional cellulose with simultaneous presence of cationic and anionic functional groups. Then, carboxymethylated diethylaminoethyl cellulose (CM-DEAEC) were produced by ionic crosslinking. Various instrumental techniques were applied to characterize the microcarriers. Biological tests were also performed to determine cell seeding efficiency, proliferation and attachment on microcarriers. Fabricated CM-DEAEC microcarriers had 1500-1800 µm diameter, +26.0 surface potential, 376% swelling behavior and 233 °C glass transition temperature respectively. The findings showed that CM-DEAEC microcarriers support cellular attachment and proliferation very well and hence are promising materials for cell therapy and tissue engineering applications.


Assuntos
Técnicas de Cultura de Células/métodos , DEAE-Celulose/análogos & derivados , Fibroblastos/citologia , Engenharia Tecidual/métodos , Adesão Celular , Proliferação de Células , Células Cultivadas , Humanos
20.
Nat Commun ; 10(1): 4491, 2019 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-31582751

RESUMO

Maintaining long-term euglycemia after intraportal islet transplantation is hampered by the considerable islet loss in the peri-transplant period attributed to inflammation, ischemia and poor angiogenesis. Here, we show that viable and functional islet organoids can be successfully generated from dissociated islet cells (ICs) and human amniotic epithelial cells (hAECs). Incorporation of hAECs into islet organoids markedly enhances engraftment, viability and graft function in a mouse type 1 diabetes model. Our results demonstrate that the integration of hAECs into islet cell organoids has great potential in the development of cell-based therapies for type 1 diabetes. Engineering of functional mini-organs using this strategy will allow the exploration of more favorable implantation sites, and can be expanded to unlimited (stem-cell-derived or xenogeneic) sources of insulin-producing cells.


Assuntos
Diabetes Mellitus Tipo 1/terapia , Células Epiteliais/metabolismo , Transplante das Ilhotas Pancreáticas/métodos , Organoides/transplante , Engenharia Tecidual/métodos , Âmnio/citologia , Animais , Sobrevivência Celular , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/terapia , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 1/induzido quimicamente , Células Epiteliais/transplante , Sobrevivência de Enxerto , Xenoenxertos/irrigação sanguínea , Xenoenxertos/metabolismo , Xenoenxertos/transplante , Humanos , Insulina/metabolismo , Ilhotas Pancreáticas/metabolismo , Camundongos , Camundongos SCID , Organoides/irrigação sanguínea , Organoides/metabolismo , Ratos , Ratos Sprague-Dawley , Medicina Regenerativa/métodos , Esferoides Celulares , Estreptozocina , Técnicas de Cultura de Tecidos/métodos , Transplante Heterólogo/métodos
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