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1.
Int J Biol Macromol ; 271(Pt 2): 132611, 2024 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-38797304

RESUMO

There is a growing demand for engineered bone tissues custom-designed to match the patient-specific defect size and in vitro models for studying bone diseases and/or drug screening. Herein, we propose a bioprinted bone tissue construct using SaOs-2 cells within alginate/gellan gum/hydroxyapatite inks. Different ink formulations were developed with varying hydroxyapatite content and then evaluated for viscoelasticity, printability, biomineralization properties, post-printing viability, proliferation, metabolic activity, and osteogenic phenotype of SaOs-2-encapsulated cells. Results indicate that ink formulations exhibit non-Newtonian shear-thinning behaviour, maintaining shape integrity and structural stability post-printing. Ink mineralization rates increase with the hydroxyapatite content, rendering them suitable for bone defect strategies. Post-printed cells in the developed constructs remain live, spreading, and metabolically active but do not proliferate. Osteogenic gene and protein expression, both early and late, show upregulation at day 7 relative to day 1, followed by downregulation at day 14. Lower hydroxyapatite content inks demonstrate up to fourfold upregulation in genes and proteins at most time points. Additionally, these constructs release calcium and phosphate at levels conducive to mineralization. Overall, the tissue-engineered miniaturized constructs not only meet the criteria for early-stage bone defect/fracture regeneration but also serve as a promising platform for drug screening and evaluating potential therapeutic treatments.

2.
Pharmaceutics ; 15(6)2023 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-37376110

RESUMO

Hydrogels based on natural polysaccharides can have unique properties and be tailored for several applications, which may be mainly limited by the fragile structure and weak mechanical properties of this type of system. We successfully prepared cryogels made of newly synthesized kefiran exopolysaccharide-chondroitin sulfate (CS) conjugate via carbodiimide-mediated coupling to overcome these drawbacks. The freeze-thawing procedure of cryogel preparation followed by lyophilization is a promising route to fabricate polymer-based scaffolds with countless and valuable biomedical applications. The novel graft macromolecular compound (kefiran-CS conjugate) was characterized through 1H-NMR and FTIR spectroscopy-which confirmed the structure of the conjugate, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA)-which mirrored good thermal stability (degradation temperature of about 215 °C) and, finally, gel permeation chromatography-size exclusion chromatography (GPC-SEC)-which proved an increased molecular weight due to chemical coupling of kefiran with CS. At the same time, the corresponding cryogels physically crosslinked after the freeze-thawing procedure were investigated by scanning electron microscopy (SEM), Micro-CT, and dynamic rheology. The results revealed a prevalent contribution of elastic/storage component to the viscoelastic behavior of cryogels in swollen state, a micromorphology with micrometer-sized open pores fully interconnected, and high porosity (ca. 90%) observed for freeze-dried cryogels. Furthermore, the metabolic activity and proliferation of human adipose stem cells (hASCs), when cultured onto the developed kefiran-CS cryogel, was maintained at a satisfactory level over 72 h. Based on the results obtained, it can be inferred that the newly freeze-dried kefiran-CS cryogels possess a host of unique properties that render them highly suitable for use in tissue engineering, regenerative medicine, drug delivery, and other biomedical applications where robust mechanical properties and biocompatibility are crucial.

3.
Am J Med Sci ; 365(6): 532-537, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36972734

RESUMO

BRAF and TERT oncogenes hotspot mutations are associated with a more aggressive outcome in thyroid carcinomas (TC). TERT promoter (pTERT) mutations (C228T and C250T) are related to cancer growth and reduced overall- and disease-free survivals in TC. We report a patient followed up for 8 years with a poorly differentiated thyroid carcinoma (PDTC) presenting an extremely aggressive course, who developed a large volume of metastases in a short period. Molecular analysis of the primary tumor revealed two pTERT mutations (C228T and C250T), and no BRAF V600E mutation. pTERT mutations C228T and C250T have been described as mutually exclusive, indicating that one mutation is enough for telomerase activation and exerts its action in thyroid tumorigenesis. This report describes both pTERT hotspot mutations in the same PDTC patient presenting a very aggressive course, even for PDTC, suggesting a relationship between the two events. However, more studies are needed to prove this causality.


Assuntos
Adenocarcinoma , Telomerase , Neoplasias da Glândula Tireoide , Humanos , Neoplasias da Glândula Tireoide/genética , Neoplasias da Glândula Tireoide/patologia , Mutação , Regiões Promotoras Genéticas/genética , Adenocarcinoma/genética , Proteínas Proto-Oncogênicas B-raf/genética , Telomerase/genética
4.
Pharmaceutics ; 14(11)2022 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-36365226

RESUMO

(1) Background: Peripheral nerve injuries represent a major clinical challenge. If nerve ends retract, there is no spontaneous regeneration and grafts are required to proximate the nerve ends and give continuity to the nerve. (2) Methods: GDNF-loaded NPs were characterized physicochemically. For that, NPs stability at different pH's was assessed, and GDNF release was studied through ELISA. In vitro studies are performed with Schwann cells, and the NPs are labeled with fluorescein-5(6)-isothiocyanate for uptake experiments with SH-SY5Y neural cells. (3) Results: GDNF-loaded NPs are stable in physiological conditions, releasing GDNF in a two-step profile, which is beneficial for nerve repair. Cell viability is improved after 1 day of culture, and the uptake is near 99.97% after 3 days of incubation. (4) Conclusions: The present work shows the efficiency of using CMCht/PAMAM NPs as a GDNF-release system to act on peripheral nerve regeneration.

5.
Bioact Mater ; 16: 403-417, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35415287

RESUMO

This study investigated the osteogenic performance of new brushite cements obtained from Li+-doped ß-tricalcium phosphate as a promising strategy for bone regeneration. Lithium (Li+) is a promising trace element to encourage the migration and proliferation of adipose-derived stem cells (hASCs) and the osteogenic differentiation-related gene expression, essential for osteogenesis. In-situ X-ray diffraction (XRD) and in-situ 1H nuclear magnetic resonance (1H NMR) measurements proved the precipitation of brushite, as main phase, and monetite, indicating that Li+ favored the formation of monetite under certain conditions. Li+ was detected in the remaining pore solution in significant amounts after the completion of hydration. Isothermal calorimetry results showed an accelerating effect of Li+, especially for low concentration of the setting retarder (phytic acid). A decrease of initial and final setting times with increasing amount of Li+ was detected and setting times could be well adjusted by varying the setting retarder concentration. The cements presented compressive mechanical strength within the ranges reported for cancellous bone. In vitro assays using hASCs showed normal metabolic and proliferative levels. The immunodetection and gene expression profile of osteogenic-related markers highlight the incorporation of Li+ for increasing the in vivo bone density. The osteogenic potential of Li-doped brushite cements may be recommended for further research on bone defect repair strategies.

6.
Chemosphere ; 299: 134307, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35339522

RESUMO

For the performance assessment of radioactive waste disposal, it is critical to predict the mobility of radionuclides in the geological barrier that hosts it. A key challenge consists of assessing the transferability of current knowledge on the retention properties deduced from model systems to in natura situations. The case of the redox-sensitive element uranium in the Callovo-Oxfordian clay formation (COx) is presented herein. Extensive experimental work was carried out with respect to parameters affecting uranium speciation (pH, PCO2, [Ca] and redox potential) with illite, COx clay fraction and raw COx claystone. The "bottom-up" approach implemented, with illite and montmorillonite as reactive phases, quantitatively explains the adsorption results of U(VI) and U(IV) on COx. While retention is high for U(IV) (Rd∼104 L kg-1), it remains very low for U(VI) (Rd∼4 L kg-1) due to the formation of soluble ternary Ca(Mg)-U(VI)-carbonate complexes. The applicability of the sorption model was then assessed by comparing predictive analyses with data characterizing the behavior of naturally-occurring U (<3 mg kg-1). The COx clay phase is the largest reservoir of naturally-occurring U (∼65%) but only a small fraction appears to be adsorbed (∼1%). Under representative site conditions (especially with respect to reducing conditions), we have concluded that ternary U(VI) complexes control U speciation in solution while U(IV) surface species dominate U adsorption, with Rd values > 70 L kg-1.


Assuntos
Urânio , Adsorção , Bentonita/química , Carbonatos , Argila , Urânio/análise
7.
Opt Express ; 30(1): 255-264, 2022 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-35201204

RESUMO

Epsilon near-zero photonics and surface polariton nanophotonics have become major fields within optics, leading to unusual and enhanced light-matter interaction. Specific dielectric responses are required in both cases, which can be achieved, e.g., via operation near a material's electronic or phononic resonance. However, this condition restricts operation to a specific, narrow frequency range. It has been shown that using a thin dielectric layer can adjust the dielectric response of a surface and, therefore, the operating frequency for achieving specific photonic excitations. Here, we show that a surface's optical properties can be tuned via the deposition/transference of ultra-thin layered van der Waals (vdW) crystals, the thicknesses of which can easily be adjusted to provide the desired response. In particular, we experimentally and theoretically show that the surface phonon resonance of a silica surface can be tuned by ∼50 cm-1 through the simple deposition of nanometer-thick exfoliated flakes of black phosphorus. The surface properties were probed by infrared nanospectroscopy, and results show a close agreement with the theory. The black phosphorus-silica layered structure effectively acts as a surface with a tunable effective dielectric constant that presents an infrared response dependent on the black phosphorus thickness. In contrast, with a lower dielectric constant, hexagonal boron nitride does not significantly tune the silica surface phonon polariton. Our approach also applies to epsilon near-zero surfaces, as theoretically shown, and to polaritonic surfaces operating at other optical ranges.

8.
Int J Oral Maxillofac Surg ; 51(3): 412-425, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34391592

RESUMO

The objective of this systematic review was to assess whether the use of topical anesthetics reduces the perception of pain during puncture and anesthetic infiltration. Twenty-two randomized controlled clinical trials, published in English on or before August 6, 2020, were found in the PubMed/MEDLINE, Scopus, and Cochrane Library databases. Risk of bias was determined for randomization and other issues. A total of 1029 patients were evaluated using parameters such as type of topical anesthetic, application site, and pain (measured on a scale). Some studies assessed more than one topical anesthetic. Seventeen of them showed a reduction in pain from needle puncture and four from infiltration. Meta-analyses for some results showed considerable statistical heterogeneity. Regarding pain during needle puncture of the maxilla, statistically significant differences were observed in the topical anesthetics group, in both the vestibular (P = 0.0002) and palatal (P = 0.005) region. This was different from the mandible, for which there was no statistically significant difference (P = 0.07). With regard to pain caused by anesthetic infiltration in the maxilla, there was no difference in the use of anesthetic in relation to the control group (P = 0.11). Given these findings, using topical anesthetics only relieves pain during needle puncture and in the maxilla. PROSPERO 2020: CRD42020206362.


Assuntos
Anestésicos Locais , Lidocaína , Anestésicos Locais/uso terapêutico , Humanos , Dor/etiologia , Dor/prevenção & controle , Medição da Dor/métodos , Percepção , Punções/efeitos adversos , Ensaios Clínicos Controlados Aleatórios como Assunto
9.
Bone ; 154: 116256, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34781047

RESUMO

Bone tissue engineering approaches have evolved towards addressing the challenges of tissue mimetic requirements over the years. Different strategies have been combining scaffolds, cells, and biologically active cues using a wide range of fabrication techniques, envisioning the mimicry of bone tissue. On the one hand, biomimetic scaffold-based strategies have been pursuing different biomaterials to produce scaffolds, combining with diverse and innovative fabrication strategies to mimic bone tissue better, surpassing bone grafts. On the other hand, biomimetic scaffold-free approaches mainly foresee replicating endochondral ossification, replacing hyaline cartilage with new bone. Finally, since bone tissue is highly vascularized, new strategies focused on developing pre-vascularized scaffolds or pre-vascularized cellular aggregates have been a motif of study. The recent biomimetic scaffold-based and scaffold-free approaches in bone tissue engineering, focusing on materials and fabrication methods used, are overviewed herein. The biomimetic vascularized approaches are also discussed, namely the development of pre-vascularized scaffolds and pre-vascularized cellular aggregates.


Assuntos
Engenharia Tecidual , Alicerces Teciduais , Materiais Biocompatíveis , Osso e Ossos , Osteogênese , Engenharia Tecidual/métodos
10.
J Mater Chem B ; 9(46): 9561-9574, 2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34761792

RESUMO

In bone tissue engineering, the development of advanced biomimetic scaffolds has led to the quest for biomotifs in scaffold design that better recreate the bone matrix structure and composition and hierarchy at different length scales. In this study, an advanced hierarchical scaffold consisting of silk fibroin combined with a decellularized cell-derived extracellular matrix and reinforced with carbon nanotubes was developed. The goal of the carbon nanotube-reinforced cell-derived matrix-silk fibroin hierarchical scaffolds is to harvest the individual properties of their constituents to introduce hierarchical capacity in order to improve standard silk fibroin scaffolds. The scaffolds were fabricated using enzymatic cross-linking, freeze modeling, and decellularization methods. The developed scaffolds were assessed for the pore structure and mechanical properties showing satisfying results to be used in bone regeneration. The developed carbon nanotube-reinforced cell-derived matrix-silk fibroin hierarchical scaffolds were shown to be bioactive in vitro and expressed no hemolytic effect. Furthermore, cellular in vitro studies on human adipose-derived stem cells (hASCs) showed that scaffolds supported cell proliferation. The hASCs seeded onto these scaffolds evidenced similar metabolic activity to standard silk fibroin scaffolds but increased ALP activity. The histological staining showed cell infiltration into the scaffolds and visible collagen production. The expression of several osteogenic markers was investigated, further supporting the osteogenic potential of the developed carbon nanotube-reinforced cell-derived matrix-silk fibroin hierarchical scaffolds. The hemolytic assay demonstrated the hemocompatibility of the hierarchical scaffolds. Overall, the carbon nanotube-reinforced cell-derived matrix-silk fibroin hierarchical scaffolds presented the required architecture for bone tissue engineering applications.


Assuntos
Materiais Biocompatíveis/química , Fibroínas/química , Nanotubos de Carbono , Células-Tronco/fisiologia , Engenharia Tecidual , Alicerces Teciduais , Proliferação de Células , Sobrevivência Celular , Humanos , Microscopia Eletrônica de Varredura
11.
Sci Rep ; 11(1): 19894, 2021 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-34615941

RESUMO

The collective dynamics of cells on surfaces and interfaces poses technological and theoretical challenges in the study of morphogenesis, tissue engineering, and cancer. Different mechanisms are at play, including, cell-cell adhesion, cell motility, and proliferation. However, the relative importance of each one is elusive. Here, experiments with a culture of glioblastoma multiforme cells on a substrate are combined with in silico modeling to infer the rate of each mechanism. By parametrizing these rates, the time-dependence of the spatial correlation observed experimentally is reproduced. The obtained results suggest a reduction in cell-cell adhesion with the density of cells. The reason for such reduction and possible implications for the collective dynamics of cancer cells are discussed.


Assuntos
Fenômenos Fisiológicos Celulares , Modelos Biológicos , Algoritmos , Adesão Celular , Linhagem Celular , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Células Cultivadas , Humanos
12.
Mater Sci Eng C Mater Biol Appl ; 129: 112413, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34579922

RESUMO

The scientific community has been doing significant efforts towards engineering new 3D bone models in recent years. Osteocytes are mechanosensitive cells that play significant roles in the maintenance of bone homeostasis. Currently, as far as we know, there are no 3D models that faithfully recapitulate a bone microenvironment capable of promoting the differentiation of osteoblasts towards osteocytes. Besides, in the existing models, the use of human cells does not prevail over the animal cell lines. For so, we propose a 3D model that may have important implications for ongoing efforts towards a better understanding of bone physiology and disease. The main aim of the current work was the promotion of an effective differentiation of osteoblasts into osteocytes by mean of using a 3D model composed of primary human osteoblasts (hOBs) cultured on Gellan Gum-Hydroxyapatite (GG-HAp) matrix under a long-term osteogenic culture. The results revealed that GG-HAp matrix stimulated a fast cell migration/entrapment, attachment, spreading, and mineralization. Moreover, the transition process from osteoblasts to osteocytes was confirmed by the expression of the osteogenic-related (ALP, Runx2, COL I, OC, OPN and OSX) and osteocyte-related (hPDPN) marker throughout the culture time. Overall, the developed 3D model holds a great promise for the treatment of various bone diseases, namely on diagnostic applications and for bone regeneration purposes.


Assuntos
Durapatita , Osteogênese , Animais , Diferenciação Celular , Humanos , Hidrogéis/farmacologia , Osteoblastos , Polissacarídeos Bacterianos
13.
J Mater Chem B ; 9(20): 4211-4218, 2021 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-33998627

RESUMO

Rheumatoid arthritis (RA) is an autoimmune and chronic inflammatory disease characterized by joint inflammation. Since the inflammatory condition plays an important role in the disease process, it is important to develop and test new therapeutic approaches that specifically target and treat joint inflammation. In this study, a human 3D inflammatory cartilage-on-a-chip model was established to test the therapeutic efficacy of anti-TNFα mAb-CS/PAMAM dendrimer NPs loaded-Tyramine-Gellan Gum in the treatment of inflammation. The results showed that the proposed therapeutic approach applied to the human monocyte cell line (THP-1) and human chondrogenic primary cells (hCH) cell-based inflammation system revealed an anti-inflammatory capacity that increased over 14 days. It was also possible to observe that Coll type II was highly expressed by inflamed hCH upon the culture with anti-TNF α mAb-CS/PAMAM dendrimer NPs, indicating that the hCH cells were able maintain their biological function. The developed preclinical model allowed us to provide more robust data on the potential therapeutic effect of anti-TNF α mAb-CS/PAMAM dendrimer NPs loaded-Ty-GG hydrogel in a physiologically relevant model.


Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Anticorpos Monoclonais/uso terapêutico , Materiais Biocompatíveis/uso terapêutico , Dendrímeros/uso terapêutico , Dispositivos Lab-On-A-Chip , Inibidores do Fator de Necrose Tumoral/uso terapêutico , Anti-Inflamatórios não Esteroides/síntese química , Anti-Inflamatórios não Esteroides/química , Anticorpos Monoclonais/química , Artrite Reumatoide/tratamento farmacológico , Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/química , Células Cultivadas , Dendrímeros/síntese química , Dendrímeros/química , Humanos , Hidrogéis/química , Inflamação/tratamento farmacológico , Nanopartículas/química , Polissacarídeos Bacterianos/química , Inibidores do Fator de Necrose Tumoral/síntese química , Inibidores do Fator de Necrose Tumoral/química , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Tiramina/química
14.
Mol Immunol ; 127: 203-211, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33011403

RESUMO

Cancer is a group of diseases involving disordered growth of abnormal cells with the potential to invade and spread to other parts of the body. Today, immunotherapy is the most efficient treatment, with fewer side effects. Notably, the employment of monoclonal antibodies to inhibit checkpoint proteins, such as CTLA-4, has caused much excitement among cancer immunotherapy researchers. Thus, in-depth analysis through quantum biochemistry and molecular dynamics simulations was performed to understand the complex formed by ipilimumab and its target CTLA-4. Our computational results provide a better understanding of the binding mechanisms and new insights about the CTLA-4: ipilimumab interaction, identifying essential amino acid residues to support the complex. Additionally, we report new interactions such as aromatic-aromatic, aromatic-sulfur, and cation-pi interactions to stabilize the CTLA-4:ipilimumab complex. Finally, quantum biochemistry analyses reveal the most important amino acid residues involved in the CTLA-4:ipilimumab interface, which were used to design synthetic peptides to inhibit CTLA-4. The computational results presented here provide a better understanding of the CTLA-4:ipilimumab binding mechanisms, and can support the development of alternative antibody-based drugs with high relevance in cancer immunotherapy.


Assuntos
Antineoplásicos/uso terapêutico , Antígeno CTLA-4/imunologia , Desenho de Fármacos , Imunoterapia , Ipilimumab/uso terapêutico , Neoplasias/imunologia , Neoplasias/terapia , Peptídeos/uso terapêutico , Antígeno CTLA-4/química , Eletricidade , Humanos , Ipilimumab/química , Simulação de Dinâmica Molecular , Peptídeos/química , Ligação Proteica , Proteólise , Termodinâmica
15.
J Mech Behav Biomed Mater ; 112: 103997, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32836095

RESUMO

Bone is a dynamic tissue with an amazing but yet limited capacity of self-healing. Bone is the second most transplanted tissue in the world and there is a huge need for bone grafts and substitutes which lead to a decrease in bone banks donors. In this study, we developed three-dimensional scaffolds based on Ti6Al4V, ZrO2 and PEEK targeting bone tissue engineering applications. Experimental mechanical compressive tests and finite element analyses were carried out to study the mechanical performance of the scaffolds. Overall, the scaffolds presented different hydrophilicity properties and a reduced elastic modulus when compared with the corresponding solid materials which can in some extension minimize the phenomenon of stress shielding. The ability as a scaffold material for bone tissue regeneration applications was evaluated in vitro by seeding human osteosarcoma (SaOS-2) cells onto the scaffolds. Then, the successful culture of SaOS-2 cells on developed scaffolds was monitored by assessment of cell's viability, proliferation and alkaline phosphatase (ALP) activity up to 14 days of culturing. The in vitro results revealed that Ti6Al4V, ZrO2 and PEEK scaffolds were cytocompatible allowing the successful culture of an osteoblastic cell line, suggesting their potential application in bone tissue engineering. Statement of Significance. The work presented is timely and relevant since it gathers both the mechanical and cellular study of non-degradable cellular structures with the potential to be used as bone scaffolds. This work allow to investigate three possible bone scaffolds solutions which exhibit a significantly reduced elastic modulus when compared with conventional solid materials. While it is generally accepted that the Ti6Al4V, ZrO2 and PEEK are candidates for such applications a further study of their features and their comparison is extremely important for a better understanding of their potential.


Assuntos
Regeneração Óssea , Engenharia Tecidual , Alicerces Teciduais , Osso e Ossos , Proliferação de Células , Módulo de Elasticidade , Humanos , Porosidade
16.
Adv Exp Med Biol ; 1230: 1-14, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32285361

RESUMO

Bone is a complex and highly dynamic tissue, which has been worldwide studied, from fundamental biology to tissue engineering fields. Even so, current in vitro models do not truly replicate the native bone tissue environment. For so, new and improved in vitro tissue models are necessary to obtain more reliable data, not only in a development point of view, but also to fasten the translation of new drugs into the clinics. In this reasoning, tissue-engineering strategies were applied to develop mimetic and three-dimensional (3D) microenvironments, which were associated with microfluidic devices for the development of more complex and realistic systems. Such devices mimic blood vessels that are present in the native tissue, thus enabling the study of complex biological mechanism as such as bone angiogenesis. More recently, 3D printing has been pursued to produce more intricate microfluidic devices and engineered tissues in a single step. The ability to print spatially controlled structures composed of different biomaterials, growth factors and cells caught the attention of scientists for the development of more efficient in vitro models. Additionally, it allows obtaining microfluidic devices and/or engineered tissues with the desired architecture within a small amount of time and with reduced costs. Recently, the use of high-resolution scanning boosted the production of patient-specific implants. Despite the difficulties associated with 3D printed structures that still need to be overcome, it has been proven to be a valuable tool to accomplish a new generation of 3D bioprinted bone-on-a-chip platforms.


Assuntos
Bioimpressão , Osso e Ossos , Dispositivos Lab-On-A-Chip , Modelos Biológicos , Impressão Tridimensional , Humanos , Técnicas In Vitro , Engenharia Tecidual
17.
Adv Exp Med Biol ; 1230: 161-171, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32285370

RESUMO

Cancer is considered the disease of the century, which can be easily understood considering its increasing incidence worldwide. Over the last years, nanotechnology has been presenting promising theranostic approaches to tackle cancer, as the development of nanoparticle-based therapies. But, regardless of the promising outcomes within in vitro settings, its translation into the clinics has been delayed. One of the main reasons is the lack of an appropriate in vitro model, capable to mimic the true environment of the human body, to test the designed nanoparticles. In fact, most of in vitro models used for the validation of nanoparticle-based therapies do not address adequately the complex barriers that naturally occur in a tumor scenario, as such as blood vessels, the interstitial fluid pressure or the interactions with surrounding cells that can hamper the proper delivery of the nanoparticles into the desired site. In this reasoning, to get a step closer to the in vivo reality, it has been proposed of the use of microfluidic devices. In fact, microfluidic devices can be designed on-demand to exhibit complex structures that mimic tissue/organ-level physiological architectures. Even so, despite microfluidic-based in vitro models do not compare with the reality and complexity of the human body, the most complex systems created up to now have been showing similar results to in vivo animal models. Microfluidic devices have been proven to be a valuable tool to accomplish more realistic tumour's environment. The recent advances in this field, and in particular, the ones enabling the rapid test of new therapies, and show great promise to be translated to the clinics will be overviewed herein.


Assuntos
Pesquisa Biomédica , Dispositivos Lab-On-A-Chip , Microfluídica , Nanopartículas , Neoplasias/patologia , Animais , Humanos , Neoplasias/irrigação sanguínea
18.
Nanomedicine ; 24: 102139, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31843662

RESUMO

The clinical translation of new cancer theranostic has been delayed by inherent cancer's heterogeneity. Additionally, this delay has been enhanced by the lack of an appropriate in vitro model, capable to produce accurate data. Nanoparticles and microfluidic devices have been used to obtain new and more efficient strategies to tackle cancer challenges. On one hand, nanoparticles-based therapeutics can be modified to target specific cells, and/or molecules, and/or modified with drugs, releasing them over time. On the other hand, microfluidic devices allow the exhibition of physiologically complex systems, incorporation of controlled flow, and control of the chemical environment. Herein, we review the use of nanoparticles and microfluidic devices to address different cancer challenges, such as detection of CTCs and biomarkers, point-of-care devices for early diagnosis and improvement of therapies. The future perspectives of cancer challenges are also addressed herein.


Assuntos
Microfluídica/métodos , Nanopartículas/química , Animais , Biomarcadores/sangue , Humanos , Neoplasias/sangue , Neoplasias/diagnóstico , Neoplasias/tratamento farmacológico , Neoplasias/terapia , Sistemas Automatizados de Assistência Junto ao Leito
19.
Materials (Basel) ; 12(11)2019 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-31195642

RESUMO

During the past two decades, tissue engineering and the regenerative medicine field have invested in the regeneration and reconstruction of pathologically altered tissues, such as cartilage, bone, skin, heart valves, nerves and tendons, and many others. The 3D structured scaffolds and hydrogels alone or combined with bioactive molecules or genes and cells are able to guide the development of functional engineered tissues, and provide mechanical support during in vivo implantation. Naturally derived and synthetic polymers, bioresorbable inorganic materials, and respective hybrids, and decellularized tissue have been considered as scaffolding biomaterials, owing to their boosted structural, mechanical, and biological properties. A diversity of biomaterials, current treatment strategies, and emergent technologies used for 3D scaffolds and hydrogel processing, and the tissue-specific considerations for scaffolding for Tissue engineering (TE) purposes are herein highlighted and discussed in depth. The newest procedures focusing on the 3D behavior and multi-cellular interactions of native tissues for further use for in vitro model processing are also outlined. Completed and ongoing preclinical research trials for TE applications using scaffolds and hydrogels, challenges, and future prospects of research in the regenerative medicine field are also presented.

20.
Materials (Basel) ; 12(13)2019 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-31252675

RESUMO

The development of bioactive and cell-responsive materials has fastened the field of bone tissue engineering. Gellan gum (GG) spongy-like hydrogels present high attractive properties for the tissue engineering field, especially due to their wide microarchitecture and tunable mechanical properties, as well as their ability to entrap the responsive cells. Lactoferrin (Lf) and Hydroxyapatite (HAp) are bioactive factors that are known to potentiate faster bone regeneration. Thus, we developed an advanced three-dimensional (3D) biomaterial by integrating these bioactive factors within GG spongy-like hydrogels. Lf-HAp spongy-like hydrogels were characterized in terms of microstructure, water uptake, degradation, and concomitant release of Lf along the time. Human adipose-derived stem cells (hASCs) were seeded and the capacity of these materials to support hASCs in culture for 21 days was assessed. Lf addition within GG spongy-like hydrogels did not change the main features of GG spongy-like hydrogels in terms of porosity, pore size, degradation, and water uptake commitment. Nevertheless, HAp addition promoted an increase of the pore wall thickness (from ~13 to 28 µm) and a decrease on porosity (from ~87% to 64%) and mean pore size (from ~12 to 20 µm), as well as on the degradability and water retention capabilities. A sustained release of Lf was observed for all the formulations up to 30 days. Cell viability assays showed that hASCs were viable during the culture period regarding cell-laden spongy-like hydrogels. Altogether, we demonstrate that GG spongy-like hydrogels containing HAp and Lf in high concentrations gathered favorable 3D bone-like microenvironment with an increased hASCs viability with the presented results.

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