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1.
Biomaterials ; 310: 122627, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38823194

RESUMO

The pre-clinical animal models often fail to predict intrinsic and idiosyncratic drug induced liver injury (DILI), thus contributing to drug failures in clinical trials, black box warnings and withdrawal of marketed drugs. This suggests a critical need for human-relevant in vitro models to predict diverse DILI phenotypes. In this study, a porcine liver extracellular matrix (ECM) based biomaterial ink with high printing fidelity, biocompatibility and tunable rheological and mechanical properties is formulated for supporting both parenchymal and non-parenchymal cells. Further, we applied 3D printing and microfluidic technology to bioengineer a human physiomimetic liver acinus model (HPLAM), recapitulating the radial hepatic cord-like structure with functional sinusoidal microvasculature network, biochemical and biophysical properties of native liver acinus. Intriguingly, the human derived hepatic cells incorporated HPLAM cultured under physiologically relevant microenvironment, acts as metabolic biofactories manifesting enhanced hepatic functionality, secretome levels and biomarkers expression over several weeks. We also report that the matured HPLAM reproduces dose- and time-dependent hepatotoxic response of human clinical relevance to drugs typically recognized for inducing diverse DILI phenotypes as compared to conventional static culture. Overall, the developed HPLAM emulates in vivo like functions and may provide a useful platform for DILI risk assessment to better determine safety and human risk.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas , Fígado , Humanos , Doença Hepática Induzida por Substâncias e Drogas/patologia , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Fígado/efeitos dos fármacos , Fígado/patologia , Animais , Suínos , Impressão Tridimensional , Microfluídica/métodos , Modelos Biológicos , Avaliação Pré-Clínica de Medicamentos/métodos , Matriz Extracelular/metabolismo , Matriz Extracelular/efeitos dos fármacos , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Biomimética/métodos
2.
Indian J Anaesth ; 67(10): 893-900, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38044921

RESUMO

Background and Aims: Posterior-transversus abdominus plane (TAP) block and transversalis fascia plane (TFP) block have been used for postoperative analgesia following caesarean delivery. We compared the analgesic efficacy of the TAP vs TFP plane blocks in patients undergoing elective caesarean delivery. Methods: We randomised 90 women undergoing caesarean delivery under spinal anaesthesia to receive either a posterior-TAP (Group-TAP), TFP (Group-TFP) or no block (Group-C) postoperatively. The primary objective was the postoperative analgesic requirements. Secondary objectives were duration of analgesia, pain scores and infra-umbilical sensory loss, which were recorded at specific intervals for 24 h. Statistical analysis was carried out using Statistical Package for Social Sciences version 16.0 software. Results: The patients requiring one, two or nil rescue analgesics were comparable between the interventions and the control (P = 0.32). The duration of analgesia was longer in Group-TAP when compared to Group-C, 4.76 (1.2) vs. 6.89 (2.4); P < 0.001, whereas Group-TFP, 5.64 (2.1) h, was not significantly different from Group-C. The static pain score in Group-TAP was significantly less than that in Group-C at 4 h and beyond 12 h (P < 0.001), whereas Group-TFP was comparable with Group-C at all time points except at 4 h and 24 h (P = 0.002). Only Group-TAP demonstrated midline infraumbilical sensory loss. Conclusion: TAP and TFP blocks did not decrease the rescue analgesic requirement compared with the control group. The posterior-TAP block prolonged the duration of analgesia by 2 h, maintained the median static pain score at 0 beyond 12 h, and demonstrated sensory loss at the infraumbilical dermatomes.

3.
Biomater Adv ; 145: 213223, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36502549

RESUMO

Biomaterials composed of silk fibroin from both mulberry and non-mulberry silkworm varieties have been investigated for their utility in tissue engineering and drug delivery, but these studies have largely excluded any evaluation of host immune response. The present study compares the macrophage activation response towards mulberry (Bombyx mori, BM) and non-mulberry (Antheraea assamensis, AA) silk types, individually and as a blend (BA) in a partial thickness rat abdominal wall defect model and in vitro primary murine bone marrow-derived macrophage (BMDM) assay. Biologic materials composed of liver extracellular matrix (LECM) and small intestinal submucosa (SIS) ECM that are recognized for constructive tissue remodeling, and polypropylene mesh that is associated with pro-inflammatory macrophage phenotype activation are used as controls in the animal model. The AA silk graft shows a host response similar to SIS with few foreign body multinucleate giant cells, vascularization, high CD206 expression, and high M2-like: M1-like macrophage phenotype ratio. Exposure to AA silk degradation products in vitro induces a higher arginase: iNOS ratio in both naive BMDM and pro-inflammatory activated BMDM; and higher Fizz1: iNOS ratio in pro-inflammatory activated BMDM. These data suggest that the AA silk supports a pro-remodeling macrophage response with potential therapeutic applications.


Assuntos
Bombyx , Fibroínas , Mariposas , Animais , Camundongos , Ratos , Bombyx/metabolismo , Ativação de Macrófagos , Seda/metabolismo , Mariposas/metabolismo
4.
ACS Biomater Sci Eng ; 8(6): 2654-2663, 2022 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-35616246

RESUMO

Effective hemorrhage control is indispensable for life-threatening emergencies in defense fields and civilian trauma. During major injuries, hemostatic agents are applied externally to mimic and accelerate the natural hemostasis process. Commercially available topical hemostatic agents are associated with several limitations, e.g., burning sensation, necrosis, futile in severe injuries, and high costs of the products. In the present study, we developed silk fibroin fiber-based formulations and evaluated their use as a cost-effective potential hemostatic agent with shortened clotting time. Silk fiber-based powder was produced following the alkaline hydrolysis process, wherein Bombyx mori silk fibroin fibers were treated with sodium hydroxide (NaOH) solution that randomly chopped the silk microfibers. Physicochemical reaction parameters, e.g., reaction temperature, molarity of NaOH solution, and incubation time, were optimized to achieve the maximum yield of microfibers. The surface properties of alkaline hydrolyzed silk microfibers (AHSMf) were analyzed by field emission scanning electron microscopy and energy dispersive X-ray studies. The water uptake capacity of AHSMf and the change in pH and temperature (∼30 °C) during blood clotting were analyzed. Further, the hemostatic potential of AHSMf was evaluated by an in vitro whole blood clotting assay using both goat and human blood. The in vitro studies demonstrated a reduced blood clotting time (CT = 20-30 s), prothrombin time (PT = ∼27%), and activated partial thromboplastin time (APTT = ∼14%) in the presence of AHSMf when compared to silk hydrogel powder (devoid of NaOH). Thus, the developed AHSMf could be a promising material to serve as a potential hemostatic agent.


Assuntos
Fibroínas , Hemostáticos , Fibroínas/química , Fibroínas/farmacologia , Hemostáticos/química , Hemostáticos/farmacologia , Pós , Seda/química , Hidróxido de Sódio
5.
ACS Biomater Sci Eng ; 8(5): 2000-2015, 2022 05 09.
Artigo em Inglês | MEDLINE | ID: mdl-35452211

RESUMO

The utility of plant tissues as scaffolding materials has been gaining significant interest in recent years owing to their unique material characteristics that are ideal for tissue regeneration. In this study, the degradation and biocompatibility of natural cellulosic scaffolds derived from Borassus flabellifer (Linn.) (BF) immature endosperm was improved by chemical oxidation and surface functionalization processes. Briefly, thus obtained cellulosic scaffolds were sequentially processed via a detergent exchange decellularization process followed by sodium periodate mediated oxidation and organosilane-based surface modification using amino (NH2)-terminated 3-aminopropyltriethoxysilane (APTES) and methyl (CH3)-terminated octadecyltrichlorosilane (OTS). Post oxidation and surface functionalization, the scaffolds showed improved physiochemical, morphological, and mechanical properties. Especially, the swelling capacity, total porosity, surface area, degradation kinetics, and mechanical behavior of scaffold were significantly higher in modified scaffold groups. The biocompatibility analysis demonstrated excellent cellular adhesion, proliferation and differentiation of osteoblasts with an evident upregulation of mineralization. Subcutaneous implantation of these scaffolds in a rat model demonstrated active angiogenesis, enhanced degradation, and excellent biocompatibility with concomitant deposition of a collagen matrix. Taken together, the native cellulosic scaffolds post chemical oxidation and surface functionalization can exclusively integrate the potential properties of native soft tissue with ameliorated in vitro and in vivo support in bone tissue engineering for nonloading bearing applications.


Assuntos
Compostos de Organossilício , Alicerces Teciduais , Animais , Regeneração Óssea , Celulose/farmacologia , Ratos , Engenharia Tecidual , Alicerces Teciduais/química
6.
ACS Appl Mater Interfaces ; 14(8): 10167-10186, 2022 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-35171571

RESUMO

Bioengineering an in vitro liver model recapitulating the native liver microarchitecture consisting of parenchymal and non-parenchymal cells is crucial in achieving cellular crosstalk and hepatic metabolic functions for accurate hepatotoxicity prediction. Bioprinting holds the promise of engineering constructs with precise control over the spatial distribution of multiple cells. Two distinct tissue-specific liver extracellular matrix (ECM)-based bioinks with excellent printability and rheological attributes are formulated for supporting parenchymal and non-parenchymal cells. A physiologically relevant human vascularized liver model is bioprinted with a novel liver ECM-based bioink laden with human adipose mesenchymal stem cell-derived hepatocyte-like cells (HLCs), human umbilical vein endothelial cells (HUVECs), and human hepatic stellate cells (HHSCs) using an extrusion-based bioprinting approach and validated for hepatotoxicity assessment. The HLC/HUVEC/HHSC-laden liver model resembles native alternate cords of hepatocytes with a functional sinusoidal lumen-like network in both horizontal and vertical directions, demonstrating enhanced albumin production, urea synthesis, and cytochrome P450 (CPR) activity. Furthermore, the liver model is evaluated for drug toxicity assessment following 24 h exposure to different concentrations of (i) non-hepatotoxicants aspirin and dexamethasone, (ii) idiosyncratic hepatotoxicant trovafloxacin mesylate, and (iii) clinical hepatotoxicant acetaminophen and troglitazone. A follow-up cell viability and metabolic competence evaluation by estimating DNA concentration, lactate dehydrogenase activity, and CPR activity revealed a dose-dependent clinically relevant hepatotoxic response. These results corroborated that the developed clinically relevant vascularized liver model is affordable and would aid pharmaceutical companies in speeding up the drug development and provide a robust platform for hepatotoxicity screening.


Assuntos
Bioimpressão , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Bioimpressão/métodos , Avaliação Pré-Clínica de Medicamentos , Células Endoteliais , Humanos , Fígado , Impressão Tridimensional , Engenharia Tecidual/métodos , Alicerces Teciduais
7.
ACS Appl Mater Interfaces ; 13(43): 50744-50759, 2021 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-34664954

RESUMO

A hostile myocardial microenvironment post ischemic injury (myocardial infarction) plays a decisive role in determining the fate of tissue-engineered approaches. Therefore, engineering hybrid 3D printed platforms that can modulate the MI microenvironment for improving implant acceptance has surfaced as a critical requirement for reconstructing an infarcted heart. Here, we have employed a non-mulberry silk-based conductive bioink comprising carbon nanotubes (CNTs) to bioprint functional 3D vascularized anisotropic cardiac constructs. Immunofluorescence staining, polymerase chain reaction-based gene expression studies, and electrophysiological studies showed that the inclusion of CNTs in the bioink played a significant role in upregulating matured cardiac biomarkers, sarcomere formation, and beating rate while promoting cardiomyocyte viability. These constructs were then microinjected with calcium peroxide and IL-10-loaded gelatin methacryloyl microspheres. Measurements of oxygen concentration revealed that these microspheres upheld the oxygen availability for maintaining cellular viability for at least 5 days in a hypoxic environment. Also, the ability of microinjected IL-10 microspheres to modulate the macrophages to anti-inflammatory M2 phenotype in vitro was uncovered using immunofluorescent staining and gene expression studies. Furthermore, in vivo subcutaneous implantation of microsphere-injected 3D constructs provided insights toward the extended time frame that was achieved for dealing with the hostile microenvironment for promoting host neovascularization and implant acceptance.


Assuntos
Bioimpressão , Interleucina-10/metabolismo , Miócitos Cardíacos/efeitos dos fármacos , Peróxidos/farmacologia , Engenharia Tecidual , Alicerces Teciduais/química , Humanos , Imunomodulação , Interleucina-10/química , Microesferas , Miócitos Cardíacos/metabolismo , Nanotubos de Carbono/química , Oxigênio/análise , Oxigênio/metabolismo , Peróxidos/química , Seda/química , Células THP-1
8.
Adv Healthc Mater ; 10(19): e2100750, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34378360

RESUMO

Cell-free polymeric tissue-engineered vascular grafts (TEVGs) have shown great promise towards clinical translation; however, their limited bioactivity and remodeling ability challenge this cause. Here, a novel cell-free bioresorbable small diameter silk TEVG system functionalized with decellularized human Wharton's jelly (dWJ) matrix is developed and successfully implanted as interposition grafts into rabbit jugular vein. Implanted TEVGs remain patent for two months and integrate with host tissue, demonstrating neo-tissue formation and constructive remodeling. Mechanistic analysis reveals that dWJ matrix is a reservoir of various immunomodulatory cytokines (Interleukin-8, 6, 10, 4 and tumor necrosis factor alpha (TNF-α)), which aids in upregulating M2 macrophage-associated genes facilitating pro-remodeling behavior. Besides, dWJ treatment to human endothelial cells upregulates the expression of functional genes (cluster of differentiation 31 (CD31), endothelial nitric oxide synthase (eNOS), and vascular endothelial (VE)-cadherin), enables faster cell migration, and elevates nitric oxide (NO) production leading to the in situ development of endothelium. The dWJ functionalized silk TEVGs support increased host cell recruitment than control, including macrophages and vascular cells. It endows superior graft remodeling in terms of a dense medial layer comprising smooth muscle cells and elevates the production of extracellular matrix proteins (collagen and elastin). Altogether, these findings suggest that dWJ functionalization imitates the usefulness of cell seeding and enables graft remodeling.


Assuntos
Prótese Vascular , Geleia de Wharton , Animais , Células Endoteliais , Humanos , Imunomodulação , Veias Jugulares , Coelhos , Seda , Engenharia Tecidual
9.
ACS Appl Mater Interfaces ; 13(21): 24401-24421, 2021 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-34019382

RESUMO

Mimicking nativelike metabolic zonation is indispensable to develop an efficient bioartificial liver model, as it facilitates physiological cues, hepatocyte polarity, and phenotypic functions. The present study shows the first evidence of hepatocyte metabolic heterogeneity in an in vitro liver model encompassing liver extracellular matrix (ECM)-functionalized silk scaffolds (LECM-SF) by altering ECM proportion. Upon static culture, individual LECM-SF scaffold supports differential synthetic and metabolic functions of cultured primary neonatal rat hepatocytes (PNRHs), owing to discrete biophysical attributes. A single in vitro liver system comprising PNRHs seeded LECM-SF scaffolds assisting periportal to pericentral gradient functions is stacked and matured in a perfusion bioreactor to simulate oxygen gradient. The scaffold with high ECM supports periportal-specific albumin synthesis, urea secretion, and bile duct formation, albeit scaffold with low ECM supports pericentral-specific cytochrome P450 activity. Extensive physicochemical characterizations confirmed the stability and interconnected porous network of scaffolds, signifying cellular infiltration and bidirectional nutrient diffusion. Furthermore, scaffolds demonstrate minimal thrombogenicity, reduced foreign-body response, and enhanced pro-remodeling macrophage activation, supporting constructive tissue remodeling. The developed liver model with zone-specific functions would be a promising avenue in bioartificial liver and drug screening.


Assuntos
Adjuvantes Imunológicos/farmacologia , Órgãos Artificiais , Matriz Extracelular/metabolismo , Hepatócitos/citologia , Fígado/metabolismo , Mimetismo Molecular , Seda/metabolismo , Animais , Animais Recém-Nascidos , Ratos
10.
J Colloid Interface Sci ; 589: 438-452, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33485251

RESUMO

HYPOTHESIS: Modeling three-dimensional (3D) in vitro culture systems recapitulating spatiotemporal characteristics of native tumor-mass has shown tremendous potential as a pre-clinical tool for drug screening. However, their applications in clinical settings are still limited due to inappropriate recapitulation of tumor topography, culture instability, and poor durability of niche support. EXPERIMENTS: Here, we have fabricated a bio-active silk composite scaffold assimilating tunable silk from Bombyx mori and - arginine-glycine-aspartate (RGD) rich silk from Antheraea assama to provide a better 3D-matrix for breast (MCF 7) and liver (HepG2) tumoroids. Cellular mechanisms underlying physiological adaptations in 3D constructs and subsequent drug responses were compared with conventional monolayer and multicellular spheroid culture. FINDINGS: Silk composite matrix assists prolonged growth and high metabolic activity (Cytochrome P450 reductase) in breast and liver 3D-tumoroids. Enhanced stemness expression (Cell surface adhesion receptor; CD44, Aldehyde dehydrogenase 1) and epithelial-mesenchymal-transition markers (E-cadherin, Vimentin) at transcript and protein levels demonstrate that bio-active matrix-assisted 3D environment augmenting metastatic potential in tumoroids. Together, enhanced secretion of Transforming growth factor ß (TGFß), anchorage-independency, and colony-forming potential of cells in the 3D-tumoroids further corroborates the aggressive behavior of cells. Moreover, the multilayered 3D-tumoroids exhibit decreased sensitivity to some known anticancer drugs (Doxorubicin and Paclitaxel). In conclusion, the bio-active silk composite matrix offers an advantage in developing robust and sustainable 3D tumoroids for a high-throughput drug screening platform.


Assuntos
Antineoplásicos , Seda , Antineoplásicos/farmacologia , Ensaios de Triagem em Larga Escala , Esferoides Celulares , Alicerces Teciduais
11.
Indian J Orthop ; 54(3): 246-255, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32399142

RESUMO

BACKGROUND: Rowing is an Olympic sport gaining popularity in India and injuries are common in these athletes. Determinants of performance, injury risk and training are all interrelated in rowing. Injuries result from various risk factors including fitness issues and improper techniques. Rowers should have adequate leg extension strength and lumbo-pelvic coordination to produce and transmit power from the legs to the oar handle. Biomechanical analysis of the rowing stroke can help in preventing injuries and optimise technique for best performance. It involves a detailed and systematic observation of movement patterns to establish the quality of the movement and provide feedback to the rower about the key variables affecting performance and injury risk. Kinetics such as foot forces and kinematics such as key joint angles can be accurately measured by instrumented foot stretcher and three-dimensional motion capture. AIM: To do a detailed review of literature regarding the incidence and risk factors for rowing injuries and to get an insight on the role of biomechanics in its management. MATERIALS AND METHODS: Literature review was carried out with standard academic search engines and databases including Science Direct, PubMed and Google Scholar using keywords of relevance. A total number of 38 articles were analysed and results were collated to compile this review report. RESULTS: Lumbar spine is most commonly injured (up to 53%), followed by rib cage (9-10%) and shoulder and other anatomical areas. Rowers with a trunk-driven rowing action will have a lower hip:trunk score and carry a high injury risk. A player with lumbar injury will take a minimum of 3-4 months to recover. CONCLUSION: Rowing injuries are common. Regular screening of the rowing athletes by comprehensive fitness and biomechanics assessment will help in prevention of injuries. Rowers need to be tested for pain, strength, flexibility, reproducibility of rowing action with modified mechanics, coordination, fatigue level, explosive power, aerobic and anaerobic endurance. Early recognition of risk factors and timely intervention is the key aspect of a successful return to play.

12.
ACS Biomater Sci Eng ; 5(11): 6137-6151, 2019 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-33405667

RESUMO

Urokinase plasminogen activator (uPA) has been extensively used as a thrombolytic drug in cases of myocardial infarction, thromboembolism, and ischemic brain stroke. Media optimization and high-density perfusion culture are the decisive factors that facilitate enhanced urokinase production in a conditioned medium. In this study, we have aimed for a high-density perfusion culture of HT1080, a human fibrosarcoma cell line, by formulating optimal media for enhanced urokinase productivity. Four scaffold variants were fabricated from silk fibroin and microfibers of Bombyx mori (BM) and Antheraea assamensis (AA) and physico-chemically characterized. Field emission scanning electron microscopy studies revealed a heterogeneous distribution of pores with interconnected networks supporting cell infiltration, attachment, and long-term viability. AA-based fiber-reinforced scaffolds (ASAF) demonstrated superior mechanical strength, integral stability, and increased cell proliferation as compared to pure silk scaffolds. Media formulation was accomplished by limiting serum concentration (2% FBS) and supplementing with 20 µg/mL arginine and 20 ng/mL TGF-ß1 to retain the stationary phase of cells and augment the urokinase production. A perfusion bioreactor culture of HT1080-laden scaffolds in the presence of formulated media was performed for improving the production of urokinase, with a maximum activity of 432 U/L. Also, gene expression analysis revealed that the individual silk scaffolds have different effects on regulating the expression of plasminogen activator urokinase and plasminogen activator urokinase receptor. In brief, our results suggest that a perfusion bioreactor culture of HT1080-laden ASAF scaffolds in formulated media promotes an increased urokinase production, such that it can be further used as a novel 3D matrix platform for industrial production of the lifesaving uPA drug.

13.
J Tissue Eng Regen Med ; 12(3): e1559-e1570, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-28987032

RESUMO

Chronic cutaneous ulcers, a complex pathophysiological diabetic condition, represent a critical clinical challenge in the current diabetes mellitus pandemic. Consequently, there is a compelling need for bioactive dressings that can trigger healing processes for complete wound repair. Silk fibroin (SF), a natural protein polymer from mulberry and non-mulberry silkworms, has properties that support accelerated wound healing rate. SF from non-mulberry variety possesses additional cell-binding motifs (arginine, glycine, and aspartate), offering cell-material interactions. This study is aimed to investigate wound healing efficacy of dressings made up of various SF varieties blended with poly(vinyl alcohol) biopolymer in alloxan-induced diabetic rabbit model. The nanofibrous mats have been developed using electrospinning and functionalized with growth factors and LL-37 antimicrobial peptide for sustained delivery. Following post 14-day treatment, non-mulberry SF (NMSF)-based dressings healed the wounds faster, in comparison with their mulberry Bombyx mori SF, poly(vinyl alcohol), and control counterparts (p < .01). NMSF-based dressings also supported faster granulation tissue development, angiogenesis, and reepithelialization of wounds. Gene expression study of matrix metalloproteinases and collagen proteins affirmed higher extent of tissue remodelling during the repair process. Furthermore, there was organized extracellular matrix deposition (collagen type I, collagen type III, elastin, and reticulin) and higher wound breaking strength in NMSF compared with other groups after 4 weeks. These results validated the potential of NMSF-based bioactive dressings to regulate extracellular matrix deposition leading to faster and complete repair of chronic diabetic cutaneous wounds.


Assuntos
Diabetes Mellitus/patologia , Matriz Extracelular/metabolismo , Nanofibras/química , Álcool de Polivinil/química , Seda/química , Pele/patologia , Cicatrização , Animais , Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Materiais Biocompatíveis/farmacologia , Biofilmes/efeitos dos fármacos , Bombyx , Linhagem Celular , Modelos Animais de Doenças , Regulação da Expressão Gênica/efeitos dos fármacos , Tecido de Granulação/efeitos dos fármacos , Tecido de Granulação/patologia , Hemostasia/efeitos dos fármacos , Humanos , Nanofibras/ultraestrutura , Neovascularização Fisiológica/efeitos dos fármacos , Peptídeos/farmacologia , Coelhos , Reepitelização/efeitos dos fármacos , Pele/efeitos dos fármacos , Cicatrização/efeitos dos fármacos , Catelicidinas
14.
Acta Biomater ; 67: 167-182, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29223705

RESUMO

The creation of in vitro functional hepatic tissue simulating micro-environmental niche of native liver is a keen area of research due to its demand in bioartificial liver (BAL) and cell-based tissue engineering. Here, we investigated the potential of novel blend (BA) silk scaffold fabricated by blending mulberry (Bombyx mori, BM) silk fibroin with cell adhesion motif (RGD) rich non-mulberry (Antheraea assamensis, AA) silk fibroin, in generating a functional liver construct. Three-dimensional (3D) porous silk scaffolds (BM, AA and BA) were physico-chemically characterized and functionally evaluated using human hepatocarcinoma cells (HepG2) and primary neonatal rat hepatocytes. The growth and distribution of hepatocytes within the scaffolds were tracked by FESEM, alamar blue proliferation assay and live/dead staining. Hemocompatible BA scaffolds supported the formation of high density hepatocyte clusters, facilitating cell-matrix and cell-cell interactions. Blend scaffolds evinced enhanced liver-specific functions of cultured hepatocytes in terms of albumin synthesis, urea synthesis and cytochrome P450 enzyme activity over 21 days. Subcutaneous implantation of scaffolds demonstrated minimal macrophage infiltration in blend scaffolds. These findings substantiate that the integral property of blend (BA) scaffold offers a befitting environment by influencing spheroidal growth of hepatocytes with enhanced biological activity. Collectively, the present study provides a new 3D bio-matrix niche for growing functional liver cells that would have future prospects in BAL as well as regenerative medicine. STATEMENT OF SIGNIFICANCE: An end stage liver disease called cirrhosis perturbs the self-healing ability and physiological functions of liver. Due to the scarcity of healthy donors, a functional in vitro hepatic construct retaining the liver-specific functions is in great demand for its prospects in bioartificial liver (BAL) and cell-based tissue engineering. Physicochemical attributes of a matrix influence the behavior of cultured hepatocytes in terms of attachment, morphology and functionality. Mulberry and non-mulberry silk fibroin presents unique amino acid sequence with difference in hydrophobicity and crystallinity. Considering this, the present study focuses on the development of a suitable three-dimensional (3D) bioactive matrix incorporating both mulberry silk fibroin and cell adhesion motif (RGD) rich non-mulberry silk fibroin. Porous silk blend scaffolds facilitated the formation of hepatocyte clusters with enhanced liver-specific functions emphasizing both cell-cell and cell-matrix interactions. Hemocompatibility and integral property of blend scaffolds offers a biological niche for seeding functional liver cells that would have future prospects in biohybrid devices.


Assuntos
Hepatócitos/citologia , Fígado Artificial , Seda/farmacologia , Alicerces Teciduais/química , Albuminas/metabolismo , Animais , Animais Recém-Nascidos , Bombyx , Adesão Celular/efeitos dos fármacos , Agregação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Força Compressiva , Sistema Enzimático do Citocromo P-450/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Células Hep G2 , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Humanos , Inflamação/patologia , Teste de Materiais , Camundongos , Porosidade , Ratos Wistar , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície , Sus scrofa , Ureia/metabolismo
15.
Biofabrication ; 9(1): 015016, 2017 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-28000609

RESUMO

The study of breast cancer metastasis is limited due to poor knowledge of molecular progression of breast tumor and varied heterogeneity. For a better understanding of tumor metastasis, a reliable 3D in vitro model bridging the gap between 2D cultures and in vivo animal model studies is essential. Our study is focused on two key points: (i) designing a 3D microenvironment for studying metastasis and (ii) simulating the metastasis milieu by inducing epithelial to mesenchymal transition (EMT) and mesenchymal to epithelial transition (MET). An electrospun gelatin nanofiber matrix (EGNF) was fabricated using electrospinning and further dip coated with different concentrations of collagen to obtain surface complexity and mechanical properties, similar to connective tissues. Nanofiber matrices were physically characterized by Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), and field-emission scanning electron microscopy (FESEM). The FTIR, AFM, and FESEM results indicated the crosslinking and confirmed the presence of pores in the nanofiber matrices. Comparative studies on biocompatibility, cell attachment, and the proliferation of MCF-7 cells on EGNF and collagen coated gelatin nanofibrous matrix (CCGM) revealed higher cellular attachment and proliferation in CCGM. CCGM with human metastatic breast cancer cell line (MCF-7) was taken to study breast cancer metastasis using estrogen (induces EMT) and progesterone (induces MET) hormones for 24 h. Quantitative real-time PCR was used for quantifying the expression of metastasis related genes, and fluorescence microscopy for verifying the invasion of cells to the matrices. The expression of E-cadherin and matrix metalloproteinase 2 (MMP 2) confirmed the occurrence of EMT and MET. Live cell imaging and cellular attachment showed significant increase of cellular invasion in crosslinked 0.15% CCGM that serves as a suitable non-toxic, biocompatible, and affordable scaffold for studying breast cancer metastasis. Our findings suggested that CCGM can be used as a tissue-like 3D model for studying breast cancer metastatic events in vitro.


Assuntos
Técnicas de Cultura de Células/métodos , Colágeno/química , Gelatina/química , Nanofibras/química , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Caderinas/genética , Caderinas/metabolismo , Adesão Celular/efeitos dos fármacos , Técnicas de Cultura de Células/instrumentação , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Transição Epitelial-Mesenquimal , Estrogênios/farmacologia , Feminino , Humanos , Células MCF-7 , Metaloproteinase 2 da Matriz/genética , Metaloproteinase 2 da Matriz/metabolismo , Microscopia de Força Atômica , Microscopia Eletrônica de Varredura , Nanofibras/toxicidade , Metástase Neoplásica , Progesterona/farmacologia
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