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1.
Eur Cell Mater ; 41: 245-268, 2021 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-33660785

RESUMO

Reconstruction of bone defects and compensation of deficient repair mechanisms represent important goals within the field of regenerative medicine and require novel safe strategies for translation into the clinic. A non-viral osteogenic gene therapeutic vector system ('hybrid vectors') was generated, combining an improved bone morphogenetic protein 2 (BMP2) gene cassette and single pro-osteogenic microRNAs (miR-148b-3p, miR-20-5p, miR-590b-5p), driven by the U6 promoter. The vectors were tested in vitro for their osteogenic differentiation potential in C2C12 and C3H/10T1/2 cell lines, using BMP2 alone as control. After confirming BMP2 expression and miRNA transcription, increased osteogenic differentiation was observed by all hybrid vectors, but most consistently by BMP2/miR-590-5p, using alkaline phosphatase enzyme activity assays and osteogenic marker mRNA quantitation, including runt-related transcription factor 2 (Runx2), collagen type 1 (Col1a1) and osteocalcin. To visualise target mRNAs of the respective miRNAs, next generation sequencing was performed, confirming down-regulation of mRNA targets of the hybrid vectors. Since the hybrid vector consisting of BMP2 and miR-590-5p showed the largest increase in osteogenic differentiation in vitro, this was tested in a mouse ectopic-bone model. Mineralisation was more than with BMP2 alone. The present study showed hybrid vectors as a novel non-viral gene therapeutic plasmid system for combining therapeutic effects of recombinant protein expression and miRNA transcription that did not add to the burden of the translation machinery, while improving the therapeutic efficacies. In vivo proof-of-principle in the context of bone regeneration suggested that such hybrid vectors will be applicable in a wide array of gene therapeutic strategies.


Assuntos
Proteína Morfogenética Óssea 2/genética , Regeneração Óssea/genética , Osso e Ossos/fisiologia , MicroRNAs/genética , Animais , Células CHO , Diferenciação Celular/genética , Linhagem Celular , Subunidade alfa 1 de Fator de Ligação ao Core/genética , Cricetulus , Regulação para Baixo/genética , Feminino , Camundongos , Osteoblastos/fisiologia , Osteocalcina/genética , Osteogênese/genética , RNA Mensageiro/genética
2.
EBioMedicine ; 64: 103196, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33483297

RESUMO

BACKGROUND: In spite of advances in the treatment of cartilage defects using cell and scaffold-based therapeutic strategies, the long-term outcome is still not satisfying since clinical scores decline years after treatment. Scaffold materials currently used in clinical settings have shown limitations in providing suitable biomechanical properties and an authentic and protective environment for regenerative cells. To tackle this problem, we developed a scaffold material based on decellularised human articular cartilage. METHODS: Human articular cartilage matrix was engraved using a CO2 laser and treated for decellularisation and glycosaminoglycan removal. Characterisation of the resulting scaffold was performed via mechanical testing, DNA and GAG quantification and in vitro cultivation with adipose-derived stromal cells (ASC). Cell vitality, adhesion and chondrogenic differentiation were assessed. An ectopic, unloaded mouse model was used for the assessment of the in vivo performance of the scaffold in combination with ASC and human as well as bovine chondrocytes. The novel scaffold was compared to a commercial collagen type I/III scaffold. FINDINGS: Crossed line engravings of the matrix allowed for a most regular and ubiquitous distribution of cells and chemical as well as enzymatic matrix treatment was performed to increase cell adhesion. The biomechanical characteristics of this novel scaffold that we term CartiScaff were found to be superior to those of commercially available materials. Neo-tissue was integrated excellently into the scaffold matrix and new collagen fibres were guided by the laser incisions towards a vertical alignment, a typical feature of native cartilage important for nutrition and biomechanics. In an ectopic, unloaded in vivo model, chondrocytes and mesenchymal stromal cells differentiated within the incisions despite the lack of growth factors and load, indicating a strong chondrogenic microenvironment within the scaffold incisions. Cells, most noticeably bone marrow-derived cells, were able to repopulate the empty chondrocyte lacunae inside the scaffold matrix. INTERPRETATION: Due to the better load-bearing, its chondrogenic effect and the ability to guide matrix-deposition, CartiScaff is a promising biomaterial to accelerate rehabilitation and to improve long term clinical success of cartilage defect treatment. FUNDING: Austrian Research Promotion Agency FFG ("CartiScaff" #842455), Lorenz Böhler Fonds (16/13), City of Vienna Competence Team Project Signaltissue (MA23, #18-08).


Assuntos
Cartilagem Articular/metabolismo , Matriz Extracelular/metabolismo , Lasers de Gás , Engenharia Tecidual/métodos , Alicerces Teciduais , Animais , Materiais Biocompatíveis , Biomarcadores , Bovinos , Adesão Celular , Diferenciação Celular , Condrogênese , Regeneração Tecidual Guiada/métodos , Humanos , Imuno-Histoquímica , Fenômenos Mecânicos , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Microtomografia por Raio-X
3.
Hernia ; 24(6): 1233-1243, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32096088

RESUMO

BACKGROUND: The interest in non-manipulated cells originating from adipose tissue has raised tremendously in the field of tissue engineering and regenerative medicine. The resulting stromal vascular fraction (SVF) cells have been successfully used in numerous clinical applications. The aim of this experimental work is, first to combine a macroporous synthetic mesh with SVF isolated using a mechanical disruption process, and to assess the effect of those cells on the early healing phase of hernia. METHODS: Human SVF cells combined with fibrin were used to coat commercial titanized polypropylene meshes. In vitro, viability and growth of the SVF cells were assessed using live/dead staining and scanning electron microscopy. The influence of SVF cells on abdominal wall hernia healing was conducted on immunodeficient rats, with a focus on short-term vascularization and fibrogenesis. RESULTS: Macroporous meshes were easily coated with SVF using a fibrin gel as temporary carrier. The in vitro experiments showed that the whole process including the isolation of human SVF cells and their coating on PP meshes did not impact on the SVF cells' viability and on their capacity to attach and to proliferate. In vivo, the SVF cells were well tolerated by the animals, and coating mesh with SVF resulted in a decrease degree of vascularity compared to control group at day 21. CONCLUSIONS: The utilization of SVF-coated mesh influences the level of angiogenesis during the early onset of tissue healing. Further long-term animal experiments are needed to confirm that this effect correlates with a more robust mesh integration compared to non-SVF-coated mesh.


Assuntos
Herniorrafia/métodos , Telas Cirúrgicas/normas , Animais , Produtos Biológicos , Modelos Animais de Doenças , Humanos , Masculino , Ratos , Ratos Nus
4.
Biomed Res Int ; 2019: 4250940, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30891456

RESUMO

The cyclic axial dynamisation of a stabilised fracture is intended to promote callus formation and bone healing. Most studies focused on biomechanical properties or the quantity of new bone formation. Far less is known about the quality of newly formed callus tissues, such as tissue distribution and arrangement within the callus. The aim of this current study was to investigate the effect of cyclic, axial dynamisation on the quantity and quality of callus in an established delayed fracture healing model. In 41 sheep transverse osteotomies with a gap size of 3 mm were stabilised with a unilateral external fixator. In 32 of these, fracture ends were axially stimulated with displacement amplitudes of 0.8 mm, 0.4 mm, 0.2 mm, or 0.0 mm, respectively, for six weeks. In the remaining 9 sheep of the control group, an additional external fixator was mounted to achieve almost total rigidity. Animal material originating from a past animal experiment was reanalysed in this study. Histological thin-ground sections were histomorphometrically analysed regarding the histological structure and composition of the defect region. A slight tendency towards an increase in size of total callus area, area of new bone (nB.Ar), and cartilage (Cg.Ar) was detected with increasing displacement amplitudes compared to the control group. At the anterior callus side nB.Ar and Cg.Ar were significantly larger than at the posterior side in all groups independent of treatment. Regarding the quality of callus, areas of very compact bone were predominant in the treatment groups whereas in the control group a slight shift to more porous bone was observed. No difference of callus compactness was observed between the anterior and the posterior side. The established method to assess the local compactness of callus areas is a useful tool to quantitatively determine the spatial distribution of new bone tissue within the callus. The application of this method in combination with biomechanical testing might reveal interesting relations between tissue distribution and bone strength that, with traditional histomorphometry, cannot be identified.


Assuntos
Calo Ósseo/patologia , Osteotomia , Ovinos/cirurgia , Animais , Densidade Óssea , Cartilagem/patologia , Modelos Animais de Doenças , Fixadores Externos , Feminino
5.
Eur Cell Mater ; 37: 113-133, 2019 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-30793275

RESUMO

The prerequisite for a successful clinical use of autologous adipose-tissue-derived cells is the highest possible regenerative potential of the applied cell population, the stromal vascular fraction (SVF). Current isolation methods depend on high enzyme concentration, lysis buffer, long incubation steps and mechanical stress, resulting in single cell dissociation. The aim of the study was to limit cell manipulation and obtain a derivative comprising therapeutic cells (microtissue-SVF) without dissociation from their natural extracellular matrix, by employing a gentle good manufacturing practice (GMP)-grade isolation. The microtissue-SVF yielded larger numbers of viable cells as compared to the improved standard-SVF, both with low enzyme concentration and minimal dead cell content. It comprised stromal tissue compounds (collagen, glycosaminoglycans, fibroblasts), capillaries and vessel structures (CD31+, smooth muscle actin+). A broad range of cell types was identified by surface-marker characterisation, including mesenchymal, haematopoietic, pericytic, blood and lymphatic vascular and epithelial cells. Subpopulations such as supra-adventitial adipose-derived stromal/stem cells and endothelial progenitor cells were significantly more abundant in the microtissue-SVF, corroborated by significantly higher potency for angiogenic tube-like structure formation in vitro. The microtissue-SVF showed the characteristic phenotype and tri-lineage mesenchymal differentiation potential in vitro and an immunomodulatory and pro-angiogenic secretome. In vivo implantation of the microtissue-SVF combined with fat demonstrated successful graft integration in nude mice. The present study demonstrated a fast and gentle isolation by minor manipulation of liposuction material, achieving a therapeutically relevant cell population with high vascularisation potential and immunomodulatory properties still embedded in a fraction of its original matrix.


Assuntos
Tecido Adiposo/citologia , Terapia Baseada em Transplante de Células e Tecidos , Adulto , Biomarcadores/metabolismo , Diferenciação Celular , Linhagem da Célula , Forma Celular , Sobrevivência Celular , Matriz Extracelular/metabolismo , Humanos , Neovascularização Fisiológica , Células Estromais/citologia , Transplante Autólogo
6.
Acta Biomater ; 86: 207-222, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30590183

RESUMO

Biomaterials currently in use for articular cartilage regeneration do not mimic the composition or architecture of hyaline cartilage, leading to the formation of repair tissue with inferior characteristics. In this study we demonstrate the use of "AuriScaff", an enzymatically perforated bovine auricular cartilage scaffold, as a novel biomaterial for repopulation with regenerative cells and for the formation of high-quality hyaline cartilage. AuriScaff features a traversing channel network, generated by selective depletion of elastic fibers, enabling uniform repopulation with therapeutic cells. The complex collagen type II matrix is left intact, as observed by immunohistochemistry, SEM and TEM. The compressive modulus is diminished, but three times higher than in the clinically used collagen type I/III scaffold that served as control. Seeding tests with human articular chondrocytes (hAC) alone and in co-culture with human adipose-derived stromal/stem cells (ASC) confirmed that the network enabled cell migration throughout the scaffold. It also guides collagen alignment along the channels and, due to the generally traverse channel alignment, newly deposited cartilage matrix corresponds with the orientation of collagen within articular cartilage. In an osteochondral plug model, AuriScaff filled the complete defect with compact collagen type II matrix and enabled chondrogenic differentiation inside the channels. Using adult articular chondrocytes from bovine origin (bAC), filling of even deep defects with high-quality hyaline-like cartilage was achieved after 6 weeks in vivo. With its composition and spatial organization, AuriScaff provides an optimal chondrogenic environment for therapeutic cells to treat cartilage defects and is expected to improve long-term outcome by channel-guided repopulation followed by matrix deposition and alignment. STATEMENT OF SIGNIFICANCE: After two decades of tissue engineering for cartilage regeneration, there is still no optimal strategy available to overcome problems such as inconsistent clinical outcome, early and late graft failures. Especially large defects are dependent on biomaterials and their scaffolding, guiding and protective function. Considering the currently used biomaterials, structure and mechanical properties appear to be insufficient to fulfill this task. The novel scaffold developed within this study is the first approach enabling the use of dense cartilage matrix, repopulate it via channels and provide the cells with a compact collagen type II environment. Due to its density, it also provides better mechanical properties than materials currently used in clinics. We therefore think, that the auricular cartilage scaffold (AuriScaff) has a high potential to improve future cartilage regeneration approaches.


Assuntos
Cartilagem da Orelha/fisiologia , Alicerces Teciduais/química , Animais , Bovinos , Diferenciação Celular , Senescência Celular , Condrócitos/citologia , Condrogênese , Colágeno Tipo II/metabolismo , Força Compressiva , DNA/metabolismo , Cartilagem da Orelha/ultraestrutura , Feminino , Glicosaminoglicanos/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Implantação de Prótese
7.
Hernia ; 22(6): 961-974, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30168006

RESUMO

BACKGROUND: Infectious complications following mesh implantation for abdominal wall repair appear in 0.7 up to 26.6% of hernia repairs and can have a detrimental impact for the patient. To prevent or to treat mesh-related infection, the scientific community is currently developing a veritable arsenal of antibacterial meshes. The numerous and increasing reports published every year describing new technologies indicate a clear clinical need, and an academic interest in solving this problem. Nevertheless, to really appreciate, to challenge, to compare and to optimize the antibacterial properties of next generation meshes, it is important to know which models are available and to understand them. PURPOSE: We proposed for the first time, a complete overview focusing only on the in vitro and in vivo models which have been employed specifically in the field of antibacterial meshes for hernia repair. RESULTS AND CONCLUSION: From this investigation, it is clear that there has been vast progress and breadth in new technologies and models to test them. However, it also shows that standardization or adoption of a more restricted number of models would improve comparability and be a benefit to the field of study.


Assuntos
Anti-Infecciosos/administração & dosagem , Herniorrafia , Modelos Animais , Modelos Biológicos , Telas Cirúrgicas , Infecção da Ferida Cirúrgica/prevenção & controle , Animais , Aderência Bacteriana , Bacteriólise , Biofilmes , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Humanos , Teste de Materiais
8.
J Tissue Eng Regen Med ; 12(6): 1352-1362, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29603903

RESUMO

A highly interesting source for adult stem cells is adipose tissue, from which the stromal vascular fraction (SVF)-a heterogeneous cell population including the adipose-derived stromal/stem cells-can be obtained. To enhance the regenerative potential of freshly isolated SVF cells, low-level light therapy (LLLT) was used. The effects of pulsed blue (475 nm), green (516 nm), and red (635 nm) light from light-emitting diodes applied on freshly isolated SVF were analysed regarding cell phenotype, cell number, viability, adenosine triphosphate content, cytotoxicity, and proliferation but also osteogenic, adipogenic, and proangiogenic differentiation potential. The colony-forming unit fibroblast assay revealed a significantly increased colony size after LLLT with red light compared with untreated cells, whereas the frequency of colony-forming cells was not affected. LLLT with green and red light resulted in a stronger capacity to form vascular tubes by SVF when cultured within 3D fibrin matrices compared with untreated cells, which was corroborated by increased number and length of the single tubes and a significantly higher concentration of vascular endothelial growth factor. Our study showed beneficial effects after LLLT on the vascularization potential and proliferation capacity of SVF cells. Therefore, LLLT using pulsed light-emitting diode light might represent a new approach for activation of freshly isolated SVF cells for direct clinical application.


Assuntos
Tecido Adiposo/citologia , Separação Celular , Terapia com Luz de Baixa Intensidade , Diferenciação Celular/efeitos da radiação , Sobrevivência Celular/efeitos da radiação , Feminino , Humanos , Pessoa de Meia-Idade , Neovascularização Fisiológica/efeitos da radiação , Células Estromais/citologia , Células Estromais/efeitos da radiação
9.
Biomaterials ; 167: 15-31, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29554478

RESUMO

The incidence of mesh-related infection after abdominal wall hernia repair is low, generally between 1 and 4%; however, worldwide, this corresponds to tens of thousands of difficult cases to treat annually. Adopting best practices in prevention is one of the keys to reduce the incidence of mesh-related infection. Once the infection is established, however, only a limited number of options are available that provides an efficient and successful treatment outcome. Over the past few years, there has been a tremendous amount of research dedicated to the functionalization of prosthetic meshes with antimicrobial properties, with some receiving regulatory approval and are currently available for clinical use. In this context, it is important to review the clinical importance of mesh infection, its risk factors, prophylaxis and pathogenicity. In addition, we give an overview of the main functionalization approaches that have been applied on meshes to confer anti-bacterial protection, the respective benefits and limitations, and finally some relevant future directions.


Assuntos
Parede Abdominal/cirurgia , Anti-Infecciosos/uso terapêutico , Materiais Biocompatíveis/uso terapêutico , Herniorrafia/efeitos adversos , Telas Cirúrgicas/efeitos adversos , Infecção da Ferida Cirúrgica/etiologia , Infecção da Ferida Cirúrgica/prevenção & controle , Animais , Anti-Infecciosos/administração & dosagem , Antibioticoprofilaxia/métodos , Materiais Biocompatíveis/administração & dosagem , Herniorrafia/métodos , Humanos , Cicatrização/efeitos dos fármacos
10.
J Tissue Eng Regen Med ; 12(2): 416-426, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28486783

RESUMO

One of the mainstays of facial rejuvenation strategies is volume restoration, which can be achieved by autologous fat grafting. In our novel approach, we treated the adipose tissue harvest site with extracorporeal shock wave therapy (ESWT) in order to improve the quality of the regenerative cells in situ. The latter was demonstrated by characterizing the cells of the stromal vascular fraction (SVF) in the harvested liposuction material regarding cell yield, adenosine triphosphate (ATP) content, proliferative capacity, surface marker profile, differentiation potential and secretory protein profile. Although the SVF cell yield was only slightly enhanced, viability and ATP concentration of freshly isolated cells as well as proliferation doublings after 3 weeks in culture were significantly increased in the ESWT compared with the untreated group. Likewise, cells expressing mesenchymal and endothelial/pericytic markers were significantly elevated concomitant with an improved differentiation capacity towards the adipogenic lineage and enhancement in specific angiogenic proteins. Hence, in situ ESWT might be applied in the future to promote cell fitness, adipogenesis and angiogenesis within the fat graft for successful facial rejuvenation strategies with potential long-term graft survival.


Assuntos
Tecido Adiposo/transplante , Tratamento por Ondas de Choque Extracorpóreas , Trifosfato de Adenosina/metabolismo , Adipogenia , Biomarcadores/metabolismo , Diferenciação Celular , Proliferação de Células , Sobrevivência Celular , Feminino , Humanos , Células Estromais/metabolismo
11.
J Tissue Eng Regen Med ; 12(1): e250-e260, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28084018

RESUMO

Gene-activated matrix (GAM)-based therapeutics for tissue regeneration are limited by efficacy, the lack of spatiotemporal control and availability of target cells, all of which impact negatively on their translation to the clinic. Here, an advanced ultrasound-responsive GAM is described containing target cells that facilitates matrix-assisted sonoporation (MAS) to induce osteogenic differentiation. Ultrasound-responsive GAMs consisting of fibrin/collagen hybrid-matrices containing microbubbles, bone morphogenetic protein BMP2/7 coexpression plasmids together with C2C12 cells were treated with ultrasound either in vitro or following parenteral intramuscular implantation in vivo. Using direct measurement for alkaline phosphatase activity, von Kossa staining and immunohistochemical analysis for osteocalcin expression, MAS-stimulated osteogenic differentiation was confirmed in the GAMs in vitro 7 days after treatment with ultrasound. At day 30 post-treatment with ultrasound, ectopic osteogenic differentiation was confirmed in vivo using X-ray microcomputed tomography and histological analysis. Osteogenic differentiation was indicated by the presence of ectopic bone structures in all animals treated with MAS. In addition, bone volumes in this group were statistically greater than those in the control groups. This novel approach of incorporating a MAS capability into GAMs could be exploited to facilitate ex vivo gene transfer with subsequent surgical implantation or alternatively provide a minimally invasive means of stimulating in situ transgene delivery for osteoinductive gene-based therapies. Copyright © 2017 John Wiley & Sons, Ltd.


Assuntos
Eletroporação/métodos , Matriz Extracelular/metabolismo , Regulação da Expressão Gênica , Terapia Genética , Osteogênese/genética , Sonicação , Ultrassom , Animais , Diferenciação Celular , Linhagem Celular , Sobrevivência Celular , Camundongos , Microtomografia por Raio-X
12.
Adv Drug Deliv Rev ; 129: 134-147, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29247766

RESUMO

Fibrin, a natural hydrogel, is the end product of the physiological blood coagulation cascade and naturally involved in wound healing. Beyond its role in hemostasis, it acts as a local reservoir for growth factors and as a provisional matrix for invading cells that drive the regenerative process. Its unique intrinsic features do not only promote wound healing directly via modulation of cell behavior but it can also be fine-tuned to evolve into a delivery system for sustained release of therapeutic biomolecules, cells and gene vectors. To further augment tissue regeneration potential, current strategies exploit and modify the chemical and physical characteristics of fibrin to employ combined incorporation of several factors and their timed release. In this work we show advanced therapeutic approaches employing fibrin matrices in wound healing and cover the many possibilities fibrin offers to the field of regenerative medicine.


Assuntos
Sistemas de Liberação de Medicamentos , Fibrina/metabolismo , Hidrogéis/farmacologia , Cicatrização/efeitos dos fármacos , Doença Aguda , Animais , Doença Crônica , Fibrina/química , Humanos , Hidrogéis/química , Hidrogéis/metabolismo
13.
Unfallchirurg ; 120(2): 176-178, 2017 Feb.
Artigo em Alemão | MEDLINE | ID: mdl-28083628

RESUMO

Basic research in traumatology supports the clinical outcome of patients in trauma care and tries to find science-based solutions for clinical problems. Furthermore, institutions for basic research in traumatology usually offer training in different skills, such as how to write a scientific paper, or practice in microsurgery or intubation. Two examples of clinically significant research topics are presented.


Assuntos
Pesquisa Biomédica/organização & administração , Modelos Organizacionais , Objetivos Organizacionais , Padrões de Prática Médica/organização & administração , Pesquisa Translacional Biomédica/organização & administração , Traumatologia/organização & administração , Alemanha
14.
Surg Endosc ; 31(12): 4973-4980, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-27800586

RESUMO

BACKGROUND: Adhesion formation remains an important issue in hernia surgery. Liquid agents were developed for easy and versatile application, especially in laparoscopy. The aim of this study was to compare the antiadhesive effect of fibrin sealant (FS, Artiss®), Icodextrin (ID, Adept®) and Polyethylene glycol (PEG, CoSeal®) alone and in combination and to evaluate the resulting effect on tissue integration of the mesh. METHODS: A total of 56 Sprague-Dawley rats were operated in open IPOM technique. A middleweight polypropylene mesh of 2 × 2 cm size was implanted and covered with 1: FS, 2: ID, 3: PEG, 4: FS + ID, 5: FS + PEG, 6: PEG + ID, 7: control group, uncovered mesh (n = 8 per treatment/control). Observation period was 30 days. Macroscopic and histological evaluation was performed. RESULTS: Severe adhesions were found in group 2 (ID), group 6 (PEG + ID) and the controls. Best results were achieved with FS alone or FS + ID. Mesh integration in the treatment groups was reduced in comparison with the control group. This is a new finding possibly relevant for the outcome of intraperitoneal mesh repair. Group 6 (PEG + ID) showed an impairment of tissue integration with <50 % of the mesh surface in seven samples. CONCLUSION: FS alone and in combination with ID yielded excellent adhesion prevention. ID alone did not show significant adhesion prevention after 30 days. Tissue integration of FS-covered meshes was superior to ID or PEG alone or combined. PEG did show adhesion prevention comparable to FS but evoked impaired tissue integration. So Artiss® is among the most potent antiadhesive agents in IPOM repair.


Assuntos
Hérnia Abdominal/cirurgia , Herniorrafia/métodos , Complicações Pós-Operatórias/prevenção & controle , Aderências Teciduais/prevenção & controle , Adesivos Teciduais/uso terapêutico , Animais , Adesivo Tecidual de Fibrina/uso terapêutico , Glucanos/uso terapêutico , Glucose/uso terapêutico , Herniorrafia/instrumentação , Icodextrina , Laparoscopia , Masculino , Polietilenoglicóis/uso terapêutico , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Telas Cirúrgicas , Aderências Teciduais/etiologia , Resultado do Tratamento
15.
Hernia ; 21(2): 305-315, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28012032

RESUMO

BACKGROUND: New biodegradable synthetic and biologic hernia implants have been promoted for rapid integration and tissue reinforcement in challenging repairs, e.g. at the hiatus or in contaminated wound fields. Interestingly, experimental data to support or falsify this assumption is scarce. METHODS: Synthetic (BioA®) and biologic implants (porcine and bovine collagen matrices Strattice® and Veritas®) have been tested in experimental onlay hernia repair in rats in observation periods of 30 and 60 days. The key outcome parameters were mesh integration and reinforcement of the tissue at the implant site over sutured and sealed defects as well as comparison to native abdominal wall. Macroscopic assessment, biomechanical analysis and histology with haematoxylin/eosin staining, collagen staining and van Willebrand factor staining for detection of neovascularization were performed. RESULTS: BioA® was well integrated. Although the matrices were already fragmented at 60 days follow-up, hernia sites treated with synthetic scaffolds showed a significantly enhanced tissue deflection and resistance to burst force when compared to the native abdominal wall. In porcine and bovine matrices, tissue integration and shrinkage were significantly inferior to BioA®. Histology revealed a lack of fibroblast ingrowth through mesh interstices in biologic samples, whereas BioA® was tightly connected to the underlying tissue by reticular collagen fibres. CONCLUSIONS: Strattice® and Veritas® yielded reduced tissue integration and significant shrinkage, prohibiting further biomechanical tests. The synthetic BioA® provides little inherent strength but reticular collagen remodelling led to an augmentation of the scar due to significantly higher burst force resistance in comparison to native tissue.


Assuntos
Hérnia Ventral/fisiopatologia , Herniorrafia/métodos , Hérnia Incisional/fisiopatologia , Telas Cirúrgicas , Cicatrização/fisiologia , Parede Abdominal/cirurgia , Implantes Absorvíveis , Animais , Materiais Biocompatíveis/administração & dosagem , Produtos Biológicos/administração & dosagem , Bovinos , Colágeno/administração & dosagem , Adesivo Tecidual de Fibrina , Hérnia Ventral/cirurgia , Hérnia Incisional/cirurgia , Masculino , Ratos , Ratos Sprague-Dawley , Suínos , Alicerces Teciduais
16.
Eur Cell Mater ; 31: 312-22, 2016 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-27215739

RESUMO

New regenerative materials and approaches need to be assessed through reliable and comparable methods for rapid translation to the clinic. There is a considerable need for proven in vitro assays that are able to reduce the burden on animal testing, by allowing assessment of biomaterial utility predictive of the results currently obtained through in vivo studies. The purpose of this multicentre review was to investigate the correlation between existing in vitro results with in vivo outcomes observed for a range of biomaterials. Members from the European consortium BioDesign, comprising 8 universities in a European multicentre study, provided data from 36 in vivo studies and 47 in vitro assays testing 93 different biomaterials. The outcomes of the in vitro and in vivo experiments were scored according to commonly recognised measures of success relevant to each experiment. The correlation of in vitro with in vivo scores for each assay alone and in combination was assessed. A surprisingly poor correlation between in vitro and in vivo assessments of biomaterials was revealed indicating a clear need for further development of relevant in vitro assays. There was no significant overall correlation between in vitro and in vivo outcome. The mean in vitro scores revealed a trend of covariance to in vivo score with 58 %. The inadequacies of the current in vitro assessments highlighted here further stress the need for the development of novel approaches to in vitro biomaterial testing and validated pre-clinical pipelines.


Assuntos
Materiais Biocompatíveis/farmacologia , Regeneração Óssea/efeitos dos fármacos , Teste de Materiais/métodos , Animais , Humanos , Camundongos , Ratos
17.
Eur Cell Mater ; 31: 191-204, 2016 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-26995192

RESUMO

Therapeutic compensation of deficient bone regeneration is a challenging task and a topic of on-going search for novel treatment strategies. One promising approach for improvement involves non-viral gene delivery using the bone morphogenetic protein-2 (BMP-2) gene to provide transient, local and sustained expression of the growth factor. However, since efficiency of non-viral gene delivery is low, this study focused on the improvement of a BMP-2 gene expression system, aiming for compensation of poor transfection efficiency. First, the native BMP-2 gene sequence was modified by codon optimisation and altered by inserting a highly truncated artificial intron (96 bp). Transfection of multiple cell lines and rat adipose-derived mesenchymal stem cells with plasmids harbouring the improved BMP-2 sequence led to a several fold increased expression rate and subsequent osteogenic differentiation. Additionally, comparing expression kinetics of elongation factor 1 alpha (EF1α) promoter with a state of the art CMV promoter revealed significantly higher BMP-2 expression when under the influence of the EF1α promoter. Results obtained by quantification of bone markers as well as osteogenic assays showed reduced sensitivity to promoter silencing effects of the EF1α promoter in rat adipose-derived mesenchymal stem cells. Finally, screening of several protein secretion signals using either luciferase or BMP-2 as reporter protein revealed no superior candidates for potential replacement of the native BMP-2 secretion signal. Taken together, by enhancing the exogenous BMP-2 expression system, low transfection efficiencies in therapeutic applications can be compensated, making safe non-viral systems even more suitable for tissue regeneration approaches.


Assuntos
Proteína Morfogenética Óssea 2/genética , Regeneração Óssea/genética , Terapia Genética/métodos , Osteogênese/genética , Engenharia Tecidual/métodos , Transfecção/métodos , Tecido Adiposo/citologia , Animais , Diferenciação Celular , Linhagem Celular , Sobrevivência Celular , Expressão Gênica/genética , Humanos , Masculino , Células-Tronco Mesenquimais/citologia , Camundongos , Fator 1 de Elongação de Peptídeos/genética , Regiões Promotoras Genéticas/genética , Ratos , Ratos Sprague-Dawley
18.
J Mater Sci Mater Med ; 27(2): 37, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26704554

RESUMO

Recent studies have demonstrated that combining cells with meshes prior to implantation successfully enhanced hernia repair. The idea is to create a biologic coating surrounding the mesh with autologous cells, before transplantation into the patient. However, due to the lack of a prompt and robust cell adhesion to the meshes, extensive in vitro cultivation is required to obtain a homogenous cell layer covering the mesh. In this context, the objective of this publication is to manufacture meshes made of silk fibres and to enhance the cytoadhesion and cytocompatibility of the biomaterial by surface immobilization of a pro-adhesive wheat germ agglutinin (lectin WGA). We first investigated the affinity between the glycoprotein WGA and cells, in solution and then after covalent immobilization of WGA on silk films. Then, we manufactured meshes made of silk fibres, tailored them with WGA grafting and finally evaluated the cytocompatibility and the inflammatory response of silk and silk-lectin meshes compared to common polypropylene mesh, using fibroblasts and peripheral blood mononuclear cells, respectively. The in vitro experiments revealed that the cytocompatibility of silk can be enhanced by surface immobilization with lectin WGA without exhibiting negative response in terms of pro-inflammatory reaction. Grafting lectin to silk meshes could bring advantages to facilitate cell-coating of meshes prior to implantation, which is an imperative prerequisite for abdominal wall tissue regeneration using cell-based therapy.


Assuntos
Materiais Biocompatíveis/síntese química , Terapia Baseada em Transplante de Células e Tecidos , Herniorrafia , Microtecnologia/métodos , Seda/química , Telas Cirúrgicas , Animais , Materiais Biocompatíveis/química , Bombyx , Terapia Baseada em Transplante de Células e Tecidos/instrumentação , Terapia Baseada em Transplante de Células e Tecidos/métodos , Herniorrafia/instrumentação , Herniorrafia/métodos , Humanos , Teste de Materiais , Camundongos , Células NIH 3T3 , Projetos Piloto , Seda/síntese química
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