scholarly journals A biomimetic engineered bone platform for advanced testing of prosthetic implants

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Martina Sladkova-Faure ◽  
Michael Pujari-Palmer ◽  
Caroline Öhman-Mägi ◽  
Alejandro López ◽  
Hanbin Wang ◽  
...  
Keyword(s):  
Calcium Deposition ◽  
Animal Testing ◽  
Scientific Validity ◽  
Matrix Deposition ◽  
Prosthetic Implants ◽  
Gene Expression Matrix ◽  
Biomimetic Scaffolds ◽  
Resolution Imaging ◽  
Preclinical And Clinical Studies

AbstractExisting methods for testing prosthetic implants suffer from critical limitations, creating an urgent need for new strategies that facilitate research and development of implants with enhanced osseointegration potential. Herein, we describe a novel, biomimetic, human bone platform for advanced testing of implants in vitro, and demonstrate the scientific validity and predictive value of this approach using an assortment of complementary evaluation methods. We anchored titanium (Ti) and stainless steel (SS) implants into biomimetic scaffolds, seeded with human induced mesenchymal stem cells, to recapitulate the osseointegration process in vitro. We show distinct patterns of gene expression, matrix deposition, and mineralization in response to the two materials, with Ti implants ultimately resulting in stronger integration strength, as seen in other preclinical and clinical studies. Interestingly, RNAseq analysis reveals that the TGF-beta and the FGF2 pathways are overexpressed in response to Ti implants, while the Wnt, BMP, and IGF pathways are overexpressed in response to SS implants. High-resolution imaging shows significantly increased tissue mineralization and calcium deposition at the tissue-implant interface in response to Ti implants, contributing to a twofold increase in pullout strength compared to SS implants. Our technology creates unprecedented research opportunities towards the design of implants and biomaterials that can be personalized, and exhibit enhanced osseointegration potential, with reduced need for animal testing.

Electromagnetic field in Alzheimer’s disease: a literature review of recent preclinical and clinical studies

2020 ◽  
Vol 17 ◽  
Author(s):  
Reem Habib Mohamad Ali Ahmad ◽  
Marc Fakhoury ◽  
Nada Lawand
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Neurodegenerative Disorder ◽  
In Vivo Studies ◽  
Key Factors ◽  
Potential Benefits ◽  
Preclinical And Clinical Studies ◽  
The Brain

: Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by the progressive loss of neurons leading to cognitive and memory decay. The main signs of AD include the irregular extracellular accumulation of amyloidbeta (Aβ) protein in the brain and the hyper-phosphorylation of tau protein inside neurons. Changes in Aβ expression or aggregation are considered key factors in the pathophysiology of sporadic and early-onset AD and correlate with the cognitive decline seen in patients with AD. Despite decades of research, current approaches in the treatment of AD are only symptomatic in nature and are not effective in slowing or reversing the course of the disease. Encouragingly, recent evidence revealed that exposure to electromagnetic fields (EMF) can delay the development of AD and improve memory. This review paper discusses findings from in vitro and in vivo studies that investigate the link between EMF and AD at the cellular and behavioural level, and highlights the potential benefits of EMF as an innovative approach for the treatment of AD.

scholarly journals Real-time monitoring of liver fibrosis through embedded sensors in a microphysiological system

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Hafiz Muhammad Umer Farooqi ◽  
Bohye Kang ◽  
Muhammad Asad Ullah Khalid ◽  
Abdul Rahim Chethikkattuveli Salih ◽  
Kinam Hyun ◽  
...  
Keyword(s):  
Cell Culture ◽  
Liver Fibrosis ◽  
Real Time ◽  
Hepatic Fibrosis ◽  
Transforming Growth Factor ◽  
Cell Monolayer ◽  
Embedded Sensors ◽  
Matrix Deposition ◽  
Tgf Β1

AbstractHepatic fibrosis is a foreshadowing of future adverse events like liver cirrhosis, liver failure, and cancer. Hepatic stellate cell activation is the main event of liver fibrosis, which results in excessive extracellular matrix deposition and hepatic parenchyma's disintegration. Several biochemical and molecular assays have been introduced for in vitro study of the hepatic fibrosis progression. However, they do not forecast real-time events happening to the in vitro models. Trans-epithelial electrical resistance (TEER) is used in cell culture science to measure cell monolayer barrier integrity. Herein, we explored TEER measurement's utility for monitoring fibrosis development in a dynamic cell culture microphysiological system. Immortal HepG2 cells and fibroblasts were co-cultured, and transforming growth factor β1 (TGF-β1) was used as a fibrosis stimulus to create a liver fibrosis-on-chip model. A glass chip-based embedded TEER and reactive oxygen species (ROS) sensors were employed to gauge the effect of TGF-β1 within the microphysiological system, which promotes a positive feedback response in fibrosis development. Furthermore, albumin, Urea, CYP450 measurements, and immunofluorescent microscopy were performed to correlate the following data with embedded sensors responses. We found that chip embedded electrochemical sensors could be used as a potential substitute for conventional end-point assays for studying fibrosis in microphysiological systems.

The Use of Biomarkers as Alternatives to Current Animal Tests on Food Chemicals

1998 ◽  
Vol 26 (4) ◽  
pp. 421-480
Author(s):  
Krys Bottrill
Keyword(s):  
Animal Studies ◽  
Developmental Toxicity ◽  
Reproductive Toxicity ◽  
In Vitro Test ◽  
Animal Testing ◽  
Dietary Biomarkers ◽  
Recent Developments ◽  
Mechanistic Basis ◽  
The Three Rs

Recent developments in biomarkers relating to the interrelationship of diet, disease and health were surveyed. Most emphasis was placed on biomarkers of deleterious effects, since these are of greatest relevance to the subject of this review. The area of greatest activity was found to be that relating to biomarkers of mutagenic, genotoxic and carcinogenic effects. This is also one of the major areas of concern in considerations of the beneficial and deleterious effects of dietary components, and also the area in which regulatory testing requires studies of the longest duration. A degree of progress has also been made in the identification and development of biomarkers relating to certain classes of target organ toxicity. Biomarkers for other types of toxicity, such as immunotoxicity, neurotoxicity, reproductive toxicity and developmental toxicity, are less developed, and further investigation in these areas is required before a comprehensive biomarker strategy can be established. A criticism that recurs constantly in the biomarker literature is the lack of standardisation in the methods used, and the lack of reference standards for the purposes of validation and quality control. It is encouraging to note the growing acknowledgement of the need for validation of biomarkers and biomarker assays. Some validation studies have already been initiated. This review puts forward proposals for criteria to be used in biomarker validation. More discussion on this subject is required. It is concluded that the use of biomarkers can, in some cases, facilitate the implementation of the Three Rs with respect to the testing of food chemicals and studies on the effects of diet on health. The greatest potential is seen to be in the refinement of animal testing, in which biomarkers could serve as early and sensitive endpoints, in order to reduce the duration of the studies and also reduce the number of animals required. Biomarkers could also contribute to establishing a mechanistic basis for in vitro test systems and to facilitating their validation and acceptance. Finally, the increased information that could result from the incorporation of biomarker determinations into population studies could reduce the need for supplementary animal studies. This review makes a number of recommendations concerning the prioritisation of future activities on dietary biomarkers in relation to the Three Rs. It is emphasised, however, that further discussions will be required among toxicologists, epidemiologists and others researching the relationship between diet and health.

Comparative Evaluation of In Vitro and In Vivo Assays for the Detection of Avian Infectious Bronchitis Virus as a Contaminant of Live Poultry Vaccines

1998 ◽  
Vol 26 (5) ◽  
pp. 629-634
Author(s):  
Emiliana Falcone ◽  
Edoardo Vignolo ◽  
Livia Di Trani ◽  
Simona Puzelli ◽  
Maria Tollis
Keyword(s):  
Infectious Bronchitis Virus ◽  
Serological Response ◽  
Avian Infectious Bronchitis Virus ◽  
Animal Testing ◽  
Rt Pcr ◽  
Pcr Assay ◽  
In Vivo Test ◽  
Infectious Bronchitis

A reverse transcriptase polymerase chain reaction (RT-PCR) assay specific for identifying avian infectious bronchitis virus (IBV) in poultry vaccines, and the serological response to IBV induced by the inoculation of chicks with a Newcastle disease vaccine spiked with the Massachusetts strain of IBV, were compared for their ability to detect IBV as a contaminant of avian vaccines. The sensitivity of the IBV-RT-PCR assay provided results which were at least equivalent to the biological effect produced by the inoculation of chicks, allowing this assay to be considered a valid alternative to animal testing in the quality control of avian immunologicals. This procedure can easily be adapted to detect a number of contaminants for which the in vivo test still represents the only available method of detection.

scholarly journals Functional regeneration and repair of tendons using biomimetic scaffolds loaded with recombinant periostin

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yu Wang ◽  
Shanshan Jin ◽  
Dan Luo ◽  
Danqing He ◽  
Chunyan Shi ◽  
...  
Keyword(s):  
Progenitor Cell ◽  
Transcriptional Profiling ◽  
Collagen Scaffold ◽  
Defect Model ◽  
Tendon Regeneration ◽  
Biomimetic Scaffolds ◽  
Functional Regeneration

AbstractTendon injuries disrupt the balance between stability and mobility, causing compromised functions and disabilities. The regeneration of mature, functional tendons remains a clinical challenge. Here, we perform transcriptional profiling of tendon developmental processes to show that the extracellular matrix-associated protein periostin (Postn) contributes to the maintenance of tendon stem/progenitor cell (TSPC) functions and promotes tendon regeneration. We show that recombinant periostin (rPOSTN) promotes the proliferation and stemness of TSPCs, and maintains the tenogenic potentials of TSPCs in vitro. We also find that rPOSTN protects TSPCs against functional impairment during long-term passage in vitro. For in vivo tendon formation, we construct a biomimetic parallel-aligned collagen scaffold to facilitate TSPC tenogenesis. Using a rat full-cut Achilles tendon defect model, we demonstrate that scaffolds loaded with rPOSTN promote endogenous TSPC recruitment, tendon regeneration and repair with native-like hierarchically organized collagen fibers. Moreover, newly regenerated tendons show recovery of mechanical properties and locomotion functions.

scholarly journals New Endeavors of (Micro)Tissue Engineering: Cells Tissues Organs on-Chip and Communication Thereof

2021 ◽  
pp. 1-15
Author(s):  
Haysam M.M.A.M. Ahmed ◽  
Liliana S. Moreira Teixeira
Keyword(s):  
Tissue Engineering ◽  
Food Additives ◽  
Market Potential ◽  
Model Systems ◽  
Human Model ◽  
Human Stem Cells ◽  
Animal Testing ◽  
Preclinical Research ◽  
On Chip

The development of new therapies is tremendously hampered by the insufficient availability of human model systems suitable for preclinical research on disease target identification, drug efficacy, and toxicity. Thus, drug failures in clinical trials are too common and too costly. Animal models or standard 2D in vitro tissue cultures, regardless of whether they are human based, are regularly not representative of specific human responses. Approaching near human tissues and organs test systems is the key goal of organs-on-chips (OoC) technology. This technology is currently showing its potential to reduce both drug development costs and time-to-market, while critically lessening animal testing. OoC are based on human (stem) cells, potentially derived from healthy or disease-affected patients, thereby amenable to personalized therapy development. It is noteworthy that the OoC market potential goes beyond pharma, with the possibility to test cosmetics, food additives, or environmental contaminants. This (micro)tissue engineering-based technology is highly multidisciplinary, combining fields such as (developmental) biology, (bio)materials, microfluidics, sensors, and imaging. The enormous potential of OoC is currently facing an exciting new challenge: emulating cross-communication between tissues and organs, to simulate more complex systemic responses, such as in cancer, or restricted to confined environments, as occurs in osteoarthritis. This review describes key examples of multiorgan/tissue-on-chip approaches, or linked organs/tissues-on-chip, focusing on challenges and promising new avenues of this advanced model system. Additionally, major emphasis is given to the translation of established tissue engineering approaches, bottom up and top down, towards the development of more complex, robust, and representative (multi)organ/tissue-on-chip approaches.

scholarly journals A Preclinical Evaluation of the Antitumor Activities of Edible and Medicinal Mushrooms: A Molecular Insight

2017 ◽  
Vol 17 (2) ◽  
pp. 200-209 ◽  
Author(s):  
Thomson Patrick Joseph ◽  
Warren Chanda ◽  
Arshad Ahmed Padhiar ◽  
Samana Batool ◽  
Shao LiQun ◽  
...  
Keyword(s):  
Side Effects ◽  
Biological Activities ◽  
Genetic Alterations ◽  
In Vivo Models ◽  
Medicinal Mushrooms ◽  
Chemotherapy Drugs ◽  
Development Of Resistance ◽  
Preclinical And Clinical Studies

Cancer is the leading cause of morbidity and mortality around the globe. For certain types of cancer, chemotherapy drugs have been extensively used for treatment. However, severe side effects and the development of resistance are the drawbacks of these agents. Therefore, development of new agents with no or minimal side effects is of utmost importance. In this regard, natural compounds are well recognized as drugs in several human ailments, including cancer. One class of fungi, “mushrooms,” contains numerous compounds that exhibit interesting biological activities, including antitumor activity. Many researchers, including our own group, are focusing on the anticancer potential of different mushrooms and the underlying molecular mechanism behind their action. The aim of this review is to discuss PI3K/AKT, Wnt-CTNNB1, and NF-κB signaling pathways, the occurrence of genetic alterations in them, the association of these aberrations with different human cancers and how different nodes of these pathways are targeted by various substances of mushroom origin. We have given evidence to propose the therapeutic attributes and possible mode of molecular actions of various mushroom-originated compounds. However, anticancer effects were typically demonstrated in in vitro and in vivo models and very limited number of studies have been conducted in the human population. It is our belief that this review will help the research community in designing concrete preclinical and clinical studies to test the anticancer potential of mushroom-originated compounds on different cancers harboring particular genetic alteration(s).

scholarly journals Adiponectin inhibits leptin signalling via multiple mechanisms to exert protective effects against hepatic fibrosis

2011 ◽  
Vol 440 (3) ◽  
pp. 385-395 ◽  
Author(s):  
Jeffrey A. Handy ◽  
Ping P. Fu ◽  
Pradeep Kumar ◽  
Jamie E. Mells ◽  
Shvetank Sharma ◽  
...  
Keyword(s):  
Hepatic Fibrosis ◽  
Leptin Receptor ◽  
Tyrosine Phosphatase ◽  
Janus Kinase ◽  
Protective Effects ◽  
Wild Type ◽  
Matrix Deposition ◽  
Matrix Metalloproteinase 1 ◽  
Expression And Activity

Adiponectin is protective against hepatic fibrosis, whereas leptin promotes fibrosis. In HSCs (hepatic stellate cells), leptin signals via a JAK2 (Janus kinase 2)/STAT3 (signal transducer and activator of transcription 3) pathway, producing effects that enhance ECM (extracellular matrix) deposition. SOCS-3 (suppressor of cytokine signalling-3) and PTP1B (protein tyrosine phosphatase 1B) are both negative regulators of JAK/STAT signalling, and recent studies have demonstrated a role for adiponectin in regulating SOCS-3 expression. In the present study we investigate mechanisms whereby adiponectin dampens leptin signalling and prevents excess ECM production. We treated culture-activated rat HSCs with recombinant adiponectin, leptin, both or neither, and also treated adiponectin knockout (Ad−/−) and wild-type mice with leptin and/or carbon tetrachloride (CCl4) or saline. We analyse JAK2 and Ob-Rb (long form of the leptin receptor) phosphorylation, and PTP1B expression and activity. We also explore potential mechanisms through which adiponectin regulates SOCS-3–Ob-Rb association. Adiponectin inhibits leptin-stimulated JAK2 activation and Ob-Rb phosphorylation in HSCs, whereas both were increased in Ad−/− mice. Adiponectin stimulates PTP1B expression and activity in vitro, whereas PTP1B expression was lower in Ad−/−mice than in wild-type mice. Adiponectin also promotes SOCS-3–Ob-R association and blocks leptin-stimulated formation of extracellular TIMP-1 (tissue inhibitor of metalloproteinases-1)–MMP-1 (matrix metalloproteinase-1) complexes in vitro. These results suggest two novel mechanisms whereby adiponectin inhibits hepatic fibrosis: (i) by promoting binding of SOCS-3 to Ob-Rb, and (ii) by stimulating PTP1B expression and activity, thus inhibiting JAK2/STAT3 signalling at multiple points.

scholarly journals Gastric Inhibitory Polypeptide as an Endogenous Factor Promoting New Bone Formation after Food Ingestion

2006 ◽  
Vol 20 (7) ◽  
pp. 1644-1651 ◽  
Author(s):  
Katsushi Tsukiyama ◽  
Yuichiro Yamada ◽  
Chizumi Yamada ◽  
Norio Harada ◽  
Yukiko Kawasaki ◽  
...  
Keyword(s):  
Bone Formation ◽  
Intracellular Signaling ◽  
Gastric Inhibitory Polypeptide ◽  
Calcium Deposition ◽  
High Turnover ◽  
Blood Calcium ◽  
Gut Hormone ◽  
High Turnover Osteoporosis ◽  
Meal Ingestion

Abstract Calcium plays a fundamental role as second messenger in intracellular signaling and bone serves as the body’s calcium reserve to tightly maintain blood calcium levels. Calcium in ingested meal is the main supply and inadequate calcium intake causes osteoporosis and bone fracture. Here, we describe a novel mechanism of how ingested calcium is deposited on bone. Meal ingestion elicits secretion of the gut hormone gastric inhibitory polypeptide (GIP) from endocrine K cells in the duodenum. Bone histomorphometrical analyses revealed that bone formation parameters in the mice lacking GIP receptor (GIPR−/−) were significantly lower than those of wild-type (GIPR+/+) mice, and that the number of osteoclasts, especially multinuclear osteoclasts, was significantly increased in GIPR−/− mice, indicating that GIPR−/− mice have high-turnover osteoporosis. In vitro examination showed the percentage of osteoblastic cells undergoing apoptosis to be significantly decreased in the presence of GIP. Because GIPR−/− mice exhibited an increased plasma calcium concentration after meal ingestion, GIP directly links calcium contained in meal to calcium deposition on bone.

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