RESUMO
Chronic respiratory diseases often necessitate lung transplantation due to irreversible damage. Organ engineering offers hope through stem cell-based organ generation. However, the crucial sterilization step in scaffold preparation poses challenges. This study conducted a systematic review of studies that analysed the extracellular matrix (ECM) conditions of decellularised lungs subjected to different sterilisation processes. A search was performed for articles published in the PubMed, Web of Sciences, Scopus, and SciELO databases according to the PRISMA guidelines. Overall, five articles that presented positive results regarding the effectiveness of the sterilisation process were selected, some of which identified functional damage in the ECM. Was possible concluded that regardless of the type of agent used, physical or chemical, all of them demonstrated that sterilisation somehow harms the ECM. An ideal protocol has not been found to be fully effective in the sterilisation of pulmonary scaffolds for use in tissue and/or organ engineering.
Assuntos
Matriz Extracelular , Pulmão , Esterilização , Alicerces Teciduais , Esterilização/métodos , Humanos , Engenharia Tecidual/métodos , AnimaisRESUMO
There are several reasons for skin damage, including genetic factors, disorders, acute trauma, hard-to-heal wounds, or surgical interventions. Whatever the cause, wounds have a substantial impact on people who experience them, their caregivers and the healthcare system. Advanced wound care products have been researched and developed, providing an opportunity for faster and more complete healing. Tissue engineering (TE) is a promising strategy that can overcome limitations when choosing a graft for a wound. Amniotic membrane is a highly abundant, readily available, and inexpensive biological tissue that does not raise ethical concerns, with many applications in different fields of TE and regenerative medicine. It has attractive physical characteristics, such as elasticity, rigidity and mechanical strength, among others. The effects can also be potentiated by association with other substances, such as hyaluronic acid and growth factors. This paper describes new perspectives involving the use of amniotic membranes.
Assuntos
Âmnio , Engenharia Tecidual , Cicatrização , Humanos , Âmnio/transplante , Ferimentos e Lesões/terapia , Medicina Regenerativa/métodosRESUMO
BACKGROUND: Tissue engineering seeks to improve, maintain, or replace the biological functions of damaged organs or tissues with biological substitutes such as the development of scaffolds. In the case of bone tissue, they must have excellent mechanical properties like native bone. OBJECTIVE: In this work, three geometric models were designed for scaffolds with different structure lattices and porosity that could be biomechanically suitable and support cell growth for trabecular bone replacement applications in tissue engineering and regenerative medicine to the proximal femur area. METHODS: Geometries were designed using computer-aided design (CAD) software and evaluated using finite element analysis in compression tests. Three loads were considered according to the daily activity: 1177 N for slow walking, 2060 N for fast walking, and 245.25 N for a person in a bipedal position. All these loads for an adult weight of 75 kg. For each of them, three biomaterials were assigned: two polymers (poly-glycolic acid (PGA) and poly-lactic acid (PLA)) and one mineral (hydroxyapatite (HA)). 54 tests were performed: 27 for each of the tests. RESULTS: The results showed Young's modulus (E) between 1 and 4 GPa. CONCLUSION: If the resultant E is in the range of 0.1 to 5 GPa, the biomaterial is considered an appropriate alternative for the trabecular bone which is the main component of the proximal bone. However, for the models applied in this study, the best option is the poly-lactic acid which will allow absorbing the acting loads.
Assuntos
Desenho Assistido por Computador , Análise de Elementos Finitos , Engenharia Tecidual , Alicerces Teciduais , Alicerces Teciduais/química , Humanos , Engenharia Tecidual/métodos , Durapatita/química , Módulo de Elasticidade , Bioimpressão/métodos , Poliésteres/química , Porosidade , Simulação por Computador , Materiais Biocompatíveis/química , Substitutos Ósseos/química , Ácido Poliglicólico/química , Impressão Tridimensional , Teste de Materiais , Osso e OssosRESUMO
Bone tissue engineering is a promising alternative to repair wounds caused by cellular or physical accidents that humans face daily. In this sense, the search for new graphene oxide (GO) nanofillers related to their degree of oxidation is born as an alternative bioactive component in forming new scaffolds. In the present study, three different GOs were synthesized with varying degrees of oxidation and studied chemically and tissue-wise. The oxidation degree was determined through infrared (FTIR), X-ray diffraction (XRD), X-ray photoelectron (XPS), and Raman spectroscopy (RS). The morphology of the samples was analyzed using scanning electron microscopy (SEM). The oxygen content was deeply described using the deconvolution of RS and XPS techniques. The latter represents the oxidation degree for each of the samples and the formation of new bonds promoted by the graphitization of the material. In the RS, two characteristic bands were observed according to the degree of oxidation and the degree of graphitization of the material represented in bands D and G with different relative intensities, suggesting that the samples have different crystallite sizes. This size was described using the Tuinstra-Koenig model, ranging between 18.7 and 25.1 nm. Finally, the bone neoformation observed in the cranial defects of critical size indicates that the F1 and F2 samples, besides being compatible and resorbable, acted as a bridge for bone healing through regeneration. This promoted healing by restoring bone and tissue structure without triggering a strong immune response.
Assuntos
Regeneração Óssea , Grafite , Engenharia Tecidual , Alicerces Teciduais , Grafite/química , Regeneração Óssea/efeitos dos fármacos , Engenharia Tecidual/métodos , Animais , Alicerces Teciduais/química , Nanoestruturas/química , Osso e Ossos/efeitos dos fármacos , Análise Espectral Raman , Oxirredução , Difração de Raios X , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Ratos , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
Bioactive and biodegradable scaffolds that mimic the natural extracellular matrix of bone serve as temporary structures to guide new bone tissue growth. In this study, 3D-printed scaffolds composed of poly (lactic acid) (PLA)-tricalcium phosphate (TCP) (90-10 wt.%) were modified with 1%, 5%, and 10 wt.% of ZnO to enhance bone tissue regeneration. A commercial chain extender named Joncryl was incorporated alongside ZnO to ensure the printability of the composites. Filaments were manufactured using a twin-screw extruder and subsequently used to print 3D scaffolds via fused filament fabrication (FFF). The scaffolds exhibited a homogeneous distribution of ZnO and TCP particles, a reproducible structure with 300 µm pores, and mechanical properties suitable for bone tissue engineering, with an elastic modulus around 100 MPa. The addition of ZnO resulted in enhanced surface roughness on the scaffolds, particularly for ZnO microparticles, achieving values up to 241 nm. This rougher topography was responsible for enhancing protein adsorption on the scaffolds, with an increase of up to 85% compared to the PLA-TCP matrix. Biological analyses demonstrated that the presence of ZnO promotes mesenchymal stem cell (MSC) proliferation and differentiation into osteoblasts. Alkaline phosphatase (ALP) activity, an important indicator of early osteogenic differentiation, increased up to 29%. The PLA-TCP composite containing 5% ZnO microparticles exhibited an optimized degradation rate and enhanced bioactivity, indicating its promising potential for bone repair applications.
Assuntos
Materiais Biocompatíveis , Regeneração Óssea , Fosfatos de Cálcio , Diferenciação Celular , Proliferação de Células , Células-Tronco Mesenquimais , Osteoblastos , Poliésteres , Impressão Tridimensional , Engenharia Tecidual , Alicerces Teciduais , Óxido de Zinco , Alicerces Teciduais/química , Fosfatos de Cálcio/química , Poliésteres/química , Regeneração Óssea/efeitos dos fármacos , Engenharia Tecidual/métodos , Células-Tronco Mesenquimais/citologia , Óxido de Zinco/química , Materiais Biocompatíveis/química , Diferenciação Celular/efeitos dos fármacos , Osteoblastos/citologia , Osteogênese/efeitos dos fármacos , Teste de Materiais , Osso e Ossos , Regeneração Tecidual Guiada/métodos , Humanos , Animais , Fosfatase Alcalina/metabolismo , Módulo de Elasticidade , Porosidade , Propriedades de SuperfícieRESUMO
In this study, a series of hydrogels were synthesized from chitosan(s) that was crosslinking with glutaraldehyde at different concentrations. Ascorbic acid in an acidic medium was used to facilitate non-covalent interactions. The chitosan(s) was obtained from shrimp cytoskeleton; while ascorbic acid was extracted from xoconostle juice. The hydrogel reaction was monitored by UV-vis spectroscopy (550 nm) to determine the reaction kinetics and reaction order at 60 °C. The hydrogels structures were characterized by NMR, FT-IR, HR-MS and SEM, while the degree of cross-linking was examined with TGA-DA. The extracellular matrices were obtained as stable hydrogels where reached maximum crosslinking was of 7 %, independent of glutaraldehyde quantity added. The rheological properties showed a behavior of weak gels and a dependence of crosslinking agent concentration on strength at different temperatures. The cytotoxicity assay showed that the gels had no adverse effects on cellular growth for all concentrations of glutaraldehyde.
Assuntos
Materiais Biocompatíveis , Quitosana , Hidrogéis , Engenharia Tecidual , Hidrogéis/química , Hidrogéis/síntese química , Materiais Biocompatíveis/química , Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/farmacologia , Quitosana/química , Quitosana/farmacologia , Quitosana/síntese química , Animais , Glutaral/química , Reologia , Reagentes de Ligações Cruzadas/químicaRESUMO
INTRODUCTION AND OBJECTIVES: There are different situations in which an extrahepatic bile duct replacement or substitute is needed, such as initial and localized stages of bile duct cancer, agenesis, stenosis, or bile duct disruption. MATERIALS AND METHODS: A prosthesis obtained by electrospinning composed of Poly (D,L-lactide-co-glycolide) (PGLA) - Polycaprolactone (PCL) - Gelatin (Gel) was developed, mechanical and biological tests were carried out to evaluate resistance to tension, biocompatibility, biodegradability, cytotoxicity, morphological analysis and cell culture. The obtained prosthesis was placed in the extrahepatic bile duct of 15 pigs with a 2-year follow-up. Liver function tests and cholangioscopy were evaluated during follow-up. RESULTS: Mechanical and biological evaluations indicate that this scaffold is biocompatible and biodegradable. The prosthesis implanted in the experimental model allowed cell adhesion, migration, and proliferation, maintaining bile duct permeability without altering liver function tests. Immunohistochemical analysis indicates the presence of biliary epithelium. CONCLUSIONS: A tubular scaffold composed of electrospun PGLA-PCL-Gel nanofibers was used for the first time to replace the extrahepatic bile duct in pigs. Mechanical and biological evaluations indicate that this scaffold is biocompatible and biodegradable, making it an excellent candidate for use in bile ducts and potentially in other tissue engineering applications.
Assuntos
Implantes Absorvíveis , Ductos Biliares Extra-Hepáticos , Gelatina , Poliésteres , Engenharia Tecidual , Alicerces Teciduais , Animais , Ductos Biliares Extra-Hepáticos/cirurgia , Engenharia Tecidual/métodos , Suínos , Teste de Materiais , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Proliferação de Células , Desenho de Prótese , Materiais Biocompatíveis , Movimento Celular , Adesão Celular , Fatores de Tempo , Testes de Função Hepática , NanofibrasRESUMO
BACKGROUND: Polymeric electrospun mats have been used as scaffolds in tissue engineering for the development of novel materials due to its characteristics. The usage of synthetic materials has gone in decline due to environmental problems associated with their synthesis and waste disposal. Biomaterials such as biopolymers have been used recently due to good compatibility on biological applications and sustainability. OBJECTIVE: The purpose of this work is to obtain novel materials based on synthetic and natural polymers for applications on tissue engineering. METHODS: Aloe vera mucilage was obtained, chemically characterized, and used as an active compound contained in electrospun mats. Polymeric scaffolds were obtained in single, coaxial and tri-layer structures, characterized and evaluated in cell culture. RESULTS: Mucilage loaded electrospun fibers showed good compatibility due to formation of hydrogen bonds between polymers and biomolecules from its structure, evidenced by FTIR spectra and thermal properties. Cell viability test showed that most of the obtained mats result on viability higher than 75%, resulting in nontoxic materials, ready to be used on scaffolding applications. CONCLUSION: Mucilage containing fibers resulted on materials with potential use on scaffolding applications due to their mechanical performance and cell viability results.
Assuntos
Aloe , Sobrevivência Celular , Gelatina , Mucilagem Vegetal , Poliésteres , Engenharia Tecidual , Alicerces Teciduais , Poliésteres/química , Engenharia Tecidual/métodos , Gelatina/química , Alicerces Teciduais/química , Sobrevivência Celular/efeitos dos fármacos , Aloe/química , Mucilagem Vegetal/química , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Teste de Materiais , Humanos , Membranas Artificiais , AnimaisRESUMO
Hybrid scaffolds that are based on PLA and PLA/PMMA with 75/25, 50/50, and 25/75 weight ratios and functionalized with 10 wt.% of bioglass nanoparticles (n-BG) were developed using an electrospinning technique with a chloroform/dimethylformamide mixture in a 9:1 ratio for bone tissue engineering applications. Neat PLA and PLA/PMMA hybrid scaffolds were developed successfully through a (CF/DMF) solvent system, obtaining a random fiber deposition that generated a porous structure with pore interconnectivity. However, with the solvent system used, it was not possible to generate fibers in the case of the neat PMMA sample. With the increase in the amount of PMMA in PLA/PMMA ratios, the fiber diameter of hybrid scaffolds decreases, and the defects (beads) in the fiber structure increase; these beads are associated with a nanoparticle agglomeration, that could be related to a low interaction between n-BG and the polymer matrix. The Young's modulus of PLA/PMMA/n-BG decreases by 34 and 80%, indicating more flexible behavior compared to neat PLA. The PLA/PMMA/n-BG scaffolds showed a bioactive property related to the presence of hydroxyapatite crystals in the fiber surface after 28 days of immersion in a Simulated Body Fluids solution (SBF). In addition, the hydrolytic degradation process of PLA/PMMA/n-BG, analyzed after 35 days of immersion in a phosphate-buffered saline solution (PBS), was less than that of the pure PLA. The in vitro analysis using an HBOF-1.19 cell line indicated that the PLA/PMMA/n-BG scaffold showed good cell viability and was able to promote cell proliferation after 7 days. On the other hand, the in vivo biocompatibility evaluated via a subdermal model in BALC male mice corroborated the good behavior of the scaffolds in avoiding the generation of a cytotoxic effect and being able to enhance the healing process, suggesting that the materials are suitable for potential applications in tissue engineering.
Assuntos
Cerâmica , Nanopartículas , Poliésteres , Polimetil Metacrilato , Engenharia Tecidual , Alicerces Teciduais , Engenharia Tecidual/métodos , Poliésteres/química , Polimetil Metacrilato/química , Alicerces Teciduais/química , Cerâmica/química , Cerâmica/farmacologia , Nanopartículas/química , Animais , Camundongos , Osso e Ossos/efeitos dos fármacos , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Humanos , Linhagem CelularRESUMO
Biosilica (BS) and spongin (SPG) from marine sponges are highlighted for their potential to promote bone regeneration. Moreover, 3D printing is introduced as a technology for producing bone grafts with optimized porous structures, allowing for better cell attachment, proliferation, and differentiation. Thus, this study aimed to characterize the BS and BS/SPG 3D printed scaffolds and to evaluate the biological effects in vitro. The scaffolds were printed using an ink containing 4 wt.% of sodium alginate. The physicochemical characteristics of BS and BS/SPG 3D printed scaffolds were analyzed by SEM, EDS, FTIR, porosity, evaluation of mass loss, and pH measurement. For in vitro analysis, the cellular viability of the MC3T3-E1 cell lineage was assessed using the AlamarBlue® assay and confocal microscopy, while genotoxicity and mineralization potential were evaluated through the micronucleus assay and Alizarin Red S, respectively. SEM analysis revealed spicules in BS, the fibrillar structure of SPG, and material degradation over the immersion period. FTIR indicated peaks corresponding to silicon oxide in BS samples and carbon oxide and amine in SPG samples. BS-SPG scaffolds exhibited higher porosity, while BS scaffolds displayed greater mass loss. pH measurements indicated a significant decrease induced by BS, which was mitigated by SPG over the experimental periods. In vitro studies demonstrated the biocompatibility and non-cytotoxicity of scaffold extracts. .Also, the scaffolds promoted cellular differentiation. The micronucleus test further confirmed the absence of genotoxicity. These findings suggest that 3D printed BS and BS/SPG scaffolds may possess desirable morphological and physicochemical properties, indicating in vitro biocompatibility.