scaffolds Dotaz Zobrazit nápovědu
Repopulace decelularizované tkáně buňkami je velmi nadějným směrem, kterým by se mohl řešit nedostatek tkání a orgánů pro transplantace, přičemž jaterní tkáňové inženýrství není výjimkou. Decelularizovaný jaterní skelet slouží jako ideální 3D prostředí pro recelularizaci, neboť je v něm zachována tkáňově specifická mikroarchitektura proteinů extracelulární matrix (ECM) s poziční informací jak pro osídlení novými buňkami, tak pro jejich migraci, růst a diferenciaci. Při použití autologních buněk by navíc nově konstruovaný štěp měl postrádat imunogenicitu v hostitelském organismu, bylo by tedy možné se kompletně vyhnout imunosupresi, která je v současnosti nutnou součástí terapie po transplantaci. Tento přehled uvádí příklady dosud provedených decelularizačních a repopulačních experimentů v játrech, přičemž upozorňuje na pokroky a poukazuje na výzvy, které je třeba řešit.
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.
- Klíčová slova
- decelularizace jater, depopulace jater,
- MeSH
- játra chemie MeSH
- lidé MeSH
- modely u zvířat MeSH
- prasata MeSH
- regenerativní lékařství metody MeSH
- tkáňové inženýrství * MeSH
- tkáňové podpůrné struktury MeSH
- transplantace jater MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- práce podpořená grantem MeSH
- přehledy MeSH
Tissue engineering (TE) and regenerative medicine are progressively developed areas due to many novel tissue replacements and implementation strategies. Increasing knowledge involving the fabrication of biomaterials with advanced physicochemical and biological characteristics, successful isolation and preparation of stem cells, incorporation of growth and differentiation factors, and biomimetic environments gives us a unique opportunity to develop various types of scaffolds for TE. The current strategies for soft tissue reconstitution or regeneration highlight the importance of novel regenerative therapies in cases of significant soft tissue loss and in cases of congenital defects, disease, trauma and ageing. Various types of biomaterials and scaffolds have been tested for soft tissue regeneration. The synthetic types of materials have gained great attention due to high versatility, tunability and easy functionalization for better biocompatibility. This article reviews the current materials that are usually the most used for the fabrication of scaffolds for soft TE; in addition, the types of scaffolds together with examples of their applications for the regenerative purposes of soft tissue, as well as their major physicochemical characteristics regarding the increased applicability of these materials in medicine, are reviewed.
- MeSH
- biokompatibilní materiály aplikace a dávkování metabolismus MeSH
- lidé MeSH
- polymery aplikace a dávkování metabolismus MeSH
- poranění měkkých tkání farmakoterapie metabolismus MeSH
- stárnutí účinky léků fyziologie MeSH
- tkáňové inženýrství metody trendy MeSH
- tkáňové podpůrné struktury * trendy MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
The scarcity of transplant allografts for diseased organs has prompted efforts at tissue regeneration using seeded scaffolds, an approach hampered by the enormity of cell types and complex architectures. Our goal was to decellularize intact organs in a manner that retained the matrix signal for differentiating pluripotent cells. We decellularized intact rat kidneys in a manner that preserved the intricate architecture and seeded them with pluripotent murine embryonic stem cells antegrade through the artery or retrograde through the ureter. Primitive precursor cells populated and proliferated within the glomerular, vascular, and tubular structures. Cells lost their embryonic appearance and expressed immunohistochemical markers for differentiation. Cells not in contact with the basement membrane matrix became apoptotic, thereby forming lumens. These observations suggest that the extracellular matrix can direct regeneration of the kidney, and studies using seeded scaffolds may help define differentiation pathways.
- MeSH
- buněčná diferenciace MeSH
- embryonální kmenové buňky cytologie MeSH
- financování organizované MeSH
- krysa rodu rattus MeSH
- kultivované buňky MeSH
- ledviny MeSH
- potkani Sprague-Dawley MeSH
- proliferace buněk MeSH
- tkáňové podpůrné struktury MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
Today, numerous studies have focused on the design of novel scaffolds for tissue engineering and regenerative medicine applications; however, several challenges still exist in terms of biocompatibility/cytocompatibility, degradability, cell attachment/proliferation, nutrient diffusion, large-scale production, and clinical translation studies. Greener and safer technologies can help to produce scaffolds with the benefits of cost-effectiveness, high biocompatibility, and biorenewability/sustainability, reducing their toxicity and possible side effects. However, some challenges persist regarding their degradability, purity, having enough porosity, and possible immunogenicity. In this context, naturally derived cellulose-based scaffolds with high biocompatibility, ease of production, availability, sustainability/renewability, and environmentally benign attributes can be applied for designing scaffolds. These cellulose-based scaffolds have shown unique mechanical properties, improved cell attachment/proliferation, multifunctionality, and enhanced biocompatibility/cytocompatibility, which make them promising candidates for tissue engineering applications. Herein, the salient developments pertaining to cellulose-based scaffolds for neural, bone, cardiovascular, and skin tissue engineering are deliberated, focusing on the challenges and opportunities.
Biodegradabilní stenty (bioresorbable vascular scaffolds, BVS) představují poslední významnou změnu přístupu v oblasti perkutánních koronárních intervencí. Idea poskytnout cévě pouze přechodnou oporu je lákavá zejména proto, že může pomoci překonat některé ze slabin současných metalických lékových stentů. Cílem tohoto přehledného článku je zasadit problematiku BVS do kontextu rychle se rozvíjejícího pole koronárních intervencí, poukázat na potenciální výhody a úskalí této technologie a shrnout dostupná preklinická i klinická data. Přestože v různých fázích vývoje je mnoho různých konceptů BVS, bližší pozornost je věnována pouze těm, které již získaly schválení ke klinickému užívání. Diskutovány jsou technologické aspekty, technika implantace a data z preklinických studií, klinických randomizovaných studií, registrů a metaanalýz.
Bioresorbable vascular scaffolds (BVS) represent the most recent substantial change in direction in the field of percutaneous coronary interventions. The idea of temporary scaffolding the vessel and disappearing thereafter is attractive as it can help overcome some of the current metallic drug-eluting stents limitations. The aim of this review article is to situate the technology of BVS in the context of the rapidly evolving domain of coronary interventions, to highlight its potential benefits and pitfalls and to summarize available evidence, both preclinical and clinical. Although many different concepts of BVS are currently in evolution, only those with certificate for clinical use are discussed in detail. This includes technological aspects, implantation techniques and results from existing preclinical studies, randomized trials, registries and meta-analyses.
Heat-treated polyacrylonitrile (HT-PAN), also referred to as black orlon (BO), is a promising carbon-based material used for applications in tissue engineering and regenerative medicine. To the best of our knowledge, no such complex bone morphology-mimicking three-dimensional (3D) BO structure has been reported to date. We report that BO can be easily made into 3D cryogel scaffolds with porous structures, using succinonitrile as a porogen. The cryogels possess a porous morphology, similar to bone tissue. The prepared scaffolds showed strong osteoconductive activity, providing excellent support for the adhesion, proliferation, and mitochondrial activity of human bone-derived cells. This effect was more apparent in scaffolds prepared from a matrix with a higher content of PAN (i.e., 10% rather than 5%). The scaffolds with 10% of PAN also showed enhanced mechanical properties, as revealed by higher compressive modulus and higher compressive strength. Therefore, these scaffolds have a robust potential for use in bone tissue engineering.
- MeSH
- akrylové pryskyřice chemie MeSH
- kosti a kostní tkáň MeSH
- lidé MeSH
- pevnost v tlaku MeSH
- poréznost MeSH
- tkáňové inženýrství MeSH
- tkáňové podpůrné struktury MeSH
- vysoká teplota MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Seriously compromised function of some organs can only be restored by transplantation. Due to the shortage of human donors, the need to find another source of organs is of primary importance. Decellularized scaffolds of non-human origin are being studied as highly potential biomaterials for tissue engineering. Their biological nature and thus the ability to provide a naturally-derived environment for human cells to adhere and grow highlights their great advantage in comparison to synthetic scaffolds. Nevertheless, since every biomaterial implanted in the body generates immune reaction, studying the interaction of the scaffold with the surrounding tissues is necessary. This review aims to summarize current knowledge on the immunogenicity of semi-xenografts involved in transplantation. Moreover, positive aspects of the interaction between xenogeneic scaffold and human cells are discussed, focusing on specific roles of proteins associated with extracellular matrix in cell adhesion and signalling.
In this study, a reproducible method of fabricating hierarchically 3D porous scaffolds with high porosity and pore interconnectivity is reported. The method is based on in-situ foaming of a dispersion of diisocyanate, polyol, water and hydroxyapatite (HA) to form a hard foamed HA/polyurethane composite which after heat treatment provided a bi-phase calcium phosphate scaffold. This technique, combining the advantages of polymer sponge and direct foaming methods, provides a better control over the macrostructure of the scaffold. A modification of the multi-scaled porous macrostructure of scaffolds produced by changing the ratio of input reactants and by sintering temperature was studied. The pore morphology, size, and distribution were characterized using a scanning electron microscope and mercury porosimetry. The pores were open and interconnected with multi-scale (from several nanometres to millimetres) sizes convenient for using in tissue engineering applications. The bioactivity was confirmed by growing an apatite layer on the surfaces after immersion in simulated body fluid. The material was biocompatible, as shown by using normal human adipose tissue-derived stem cells (ASC). When seeded onto the scaffolds, the ASC adhered and remained healthy while maintaining their typical morphology.
Current methods for assessing cell proliferation in 3D scaffolds rely on changes in metabolic activity or total DNA, however, direct quantification of cell number in 3D scaffolds remains a challenge. To address this issue, we developed an unbiased stereology approach that uses systematic-random sampling and thin focal-plane optical sectioning of the scaffolds followed by estimation of total cell number (StereoCount). This approach was validated against an indirect method for measuring the total DNA (DNA content); and the Bürker counting chamber, the current reference method for quantifying cell number. We assessed the total cell number for cell seeding density (cells per unit volume) across four values and compared the methods in terms of accuracy, ease-of-use and time demands. The accuracy of StereoCount markedly outperformed the DNA content for cases with ~ 10,000 and ~ 125,000 cells/scaffold. For cases with ~ 250,000 and ~ 375,000 cells/scaffold both StereoCount and DNA content showed lower accuracy than the Bürker but did not differ from each other. In terms of ease-of-use, there was a strong advantage for the StereoCount due to output in terms of absolute cell numbers along with the possibility for an overview of cell distribution and future use of automation for high throughput analysis. Taking together, the StereoCount method is an efficient approach for direct cell quantification in 3D collagen scaffolds. Its major benefit is that automated StereoCount could accelerate research using 3D scaffolds focused on drug discovery for a wide variety of human diseases.
Nanofibrous materials present unique properties favorable in many biomedicine and industrial applications. In this research we evaluated biodegradation, tissue response and general toxicity of nanofibrous poly(lactic acid) (PLA) and polycaprolactone (PCL) scaffolds produced by conventional method of electrospinning and using NanoMatrix3D® (NM3D® ) technology. Mass density, scanning electron microscopy and in vitro degradation (static and dynamic) were used for material characterization, and subcutaneous, intramuscular and intraperitoneal implantation - for in vivo tests. Biochemical blood analysis and histology were used to assess toxicity and tissue response. Pore size and fiber diameter did not differ in conventional and NM3D® PLA and PCL materials, but mass density was significantly lower in NM3D® ones. Scaffolds made by conventional method showed toxic effect during the in-vivo tests due to residual concentration of chloroform that released with material degradation. NM3D® method allowed cleaning scaffolds from residual solutions that made them nontoxic and biocompatible. Subcutaneous, intramuscular and intraperitoneal implantation of PCL and PLA NM3D® electrospun nanofibrous scaffolds showed their appropriate cell conductive properties, tissue and vessels formation in all sites. Thus, NM3D® PCL and PLA nanofibrous electrospun scaffolds can be used in the field of tissue engineering, surgery, wound healing, drug delivery, and so forth, due to their unique properties, nontoxicity and biocompatibility. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 2200-2212, 2018.
