Effects of Collagen Microstructure on the Transport Properties of Vascularized Engineered Tissues

Author(s):  
Seungman Park ◽  
Catherine Whittington ◽  
Mervin C. Yoder ◽  
Sherry Voytik-Harbin ◽  
Bumsoo Han

When vascular perfusion is compromised within the body, a number of physiological phenomena can occur, including the progression of disease states (e.g. peripheral vascular disease), impaired wound healing, and organ/tissue transplant failure. Therefore, there is a need for an engineered tissue construct that promotes therapeutic vasculogenesis by enhancing the formation of functional, stabilized vessel networks that have the ability to integrate with the host vasculature. In order to restore tissue structure and function, a matrix-based delivery system, which combines a biopolymer and endothelial precursor cells, is necessary to ensure the localization and guidance of vessel formation and stabilization.

2016 ◽  
Vol 96 (3) ◽  
pp. 911-973 ◽  
Author(s):  
John P. M. White ◽  
Mario Cibelli ◽  
Laszlo Urban ◽  
Bernd Nilius ◽  
J. Graham McGeown ◽  
...  

Transient receptor potential vanilloid type 4 (TRPV4) is a calcium-permeable nonselective cation channel, originally described in 2000 by research teams led by Schultz ( Nat Cell Biol 2: 695 –702, 2000) and Liedtke ( Cell 103: 525–535, 2000). TRPV4 is now recognized as being a polymodal ionotropic receptor that is activated by a disparate array of stimuli, ranging from hypotonicity to heat and acidic pH. Importantly, this ion channel is constitutively expressed and capable of spontaneous activity in the absence of agonist stimulation, which suggests that it serves important physiological functions, as does its widespread dissemination throughout the body and its capacity to interact with other proteins. Not surprisingly, therefore, it has emerged more recently that TRPV4 fulfills a great number of important physiological roles and that various disease states are attributable to the absence, or abnormal functioning, of this ion channel. Here, we review the known characteristics of this ion channel's structure, localization and function, including its activators, and examine its functional importance in health and disease.


2019 ◽  
Vol 12 (5) ◽  
pp. 611-619 ◽  
Author(s):  
Onur Yilmaz ◽  
Baris Afsar ◽  
Alberto Ortiz ◽  
Mehmet Kanbay

AbstractThe endothelium is the largest organ in the body and recent studies have shown that the endothelial glycocalyx (eGCX) plays a major role in health and disease states. The integrity of eGCX is vital for homoeostasis and disruption of its structure and function plays a major role in several pathologic conditions. An increased understanding of the numerous pathophysiological roles of eGCX may lead to the development of potential surrogate markers for endothelial injury or novel therapeutic targets. This review provides a state-of-the-art update on the structure and function of the eGCX, emphasizing the current understanding of interorgan crosstalk between the eGCX and other organs that might also contribute to the pathogenesis of kidney diseases.


2020 ◽  
Vol 27 (3) ◽  
pp. 201-209
Author(s):  
Syed Saqib Ali ◽  
Mohammad Khalid Zia ◽  
Tooba Siddiqui ◽  
Haseeb Ahsan ◽  
Fahim Halim Khan

Background: Ascorbic acid is a classic dietary antioxidant which plays an important role in the body of human beings. It is commonly found in various foods as well as taken as dietary supplement. Objective: The plasma ascorbic acid concentration may range from low, as in chronic or acute oxidative stress to high if delivered intravenously during cancer treatment. Sheep alpha-2- macroglobulin (α2M), a human α2M homologue is a large tetrameric glycoprotein of 630 kDa with antiproteinase activity, found in sheep’s blood. Methods: In the present study, the interaction of ascorbic acid with alpha-2-macroglobulin was explored in the presence of visible light by utilizing various spectroscopic techniques and isothermal titration calorimetry (ITC). Results: UV-vis and fluorescence spectroscopy suggests the formation of a complex between ascorbic acid and α2M apparent by increased absorbance and decreased fluorescence. Secondary structural changes in the α2M were investigated by CD and FT-IR spectroscopy. Our findings suggest the induction of subtle conformational changes in α2M induced by ascorbic acid. Thermodynamics signatures of ascorbic acid and α2M interaction indicate that the binding is an enthalpy-driven process. Conclusion: It is possible that ascorbic acid binds and compromises antiproteinase activity of α2M by inducing changes in the secondary structure of the protein.


2020 ◽  
Vol 16 (1) ◽  
pp. 4-12
Author(s):  
Vandana Garg ◽  
Rohit Dutt

Background: Fever, is known as pyrexia, may occur due to infection, inflammation, or any tissue damage and disease states. Normally, the infected or damaged tissue initiates the enhanced formation of pro-inflammatory mediators like cytokines which further increases the synthesis of prostaglandin E2 (PgE2) near the hypothalamic area and thereby trigger the hypothalamus to elevate the body temperature. Objective: Antipyretics are the agents which reduce the elevated body temperature. The most commonly used antipyretic agent, paracetamol, may be fatal due to its side effects. Methods: In this review paper, Chemical Abstracts, Google Scholar, PubMed, and Science Direct were the sources for the published article to collect information regarding antipyretic activity. Results: This review compiles the antipyretic plants that may be useful to treat fever due to various diseases. Conclusion: These medicinal plants could be good alternatives for traditional allopathic antipyretics.


Author(s):  
Steven N. Dworkin

This book describes the linguistic structures that constitute Medieval or Old Spanish as preserved in texts written prior to the beginning of the sixteenth century. It emphasizes those structures that contrast with the modern standard language. Chapter 1 presents methodological issues raised by the study of a language preserved only in written sources. Chapter 2 examines questions involved in reconstructing the sound system of Old Spanish before discussing relevant phonetic and phonological details. The chapter ends with an overview of Old Spanish spelling practices. Chapter 3 presents in some detail the nominal, verbal, and pronominal morphology of the language, with attention to regional variants. Chapter 4 describes selected syntactic structures, with emphasis on the noun phrase, verb phrase, object pronoun placement, subject-verb-object word order, verb tense, aspect, and mood. Chapter 5 begins with an extensive list of Old Spanish nouns, adjectives, verbs, and function words that have not survived into the modern standard language. It then presents examples of coexisting variants (doublets) and changes of meaning, and finishes with an overview of the creation of neologisms in the medieval language through derivational morphology (prefixation, suffixation, compounding). The book concludes with an anthology composed of three extracts from Spanish prose texts, one each from the thirteenth, fourteenth, and fifteenth centuries. The extracts contain footnotes that highlight relevant morphological, syntactic, and lexical features, with cross references to the relevant sections in the body of the book.


Antioxidants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 486
Author(s):  
Valerio Ciccone ◽  
Shirley Genah ◽  
Lucia Morbidelli

The vascular endothelium consists of a single layer of squamous endothelial cells (ECs) lining the inner surface of blood vessels. Nowadays, it is no longer considered as a simple barrier between the blood and vessel wall, but a central hub to control blood flow homeostasis and fulfill tissue metabolic demands by furnishing oxygen and nutrients. The endothelium regulates the proper functioning of vessels and microcirculation, in terms of tone control, blood fluidity, and fine tuning of inflammatory and redox reactions within the vessel wall and in surrounding tissues. This multiplicity of effects is due to the ability of ECs to produce, process, and release key modulators. Among these, gasotransmitters such as nitric oxide (NO) and hydrogen sulfide (H2S) are very active molecules constitutively produced by endotheliocytes for the maintenance and control of vascular physiological functions, while their impairment is responsible for endothelial dysfunction and cardiovascular disorders such as hypertension, atherosclerosis, and impaired wound healing and vascularization due to diabetes, infections, and ischemia. Upregulation of H2S producing enzymes and administration of H2S donors can be considered as innovative therapeutic approaches to improve EC biology and function, to revert endothelial dysfunction or to prevent cardiovascular disease progression. This review will focus on the beneficial autocrine/paracrine properties of H2S on ECs and the state of the art on H2S potentiating drugs and tools.


Biology ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 287
Author(s):  
Yew Rong Kong ◽  
Yong Xin Jong ◽  
Manisha Balakrishnan ◽  
Zhui Ken Bok ◽  
Janice Kwan Kah Weng ◽  
...  

Oxidative stress is a result of disruption in the balance between antioxidants and pro-oxidants in which subsequently impacting on redox signaling, causing cell and tissue damages. It leads to a range of medical conditions including inflammation, skin aging, impaired wound healing, chronic diseases and cancers but these conditions can be managed properly with the aid of antioxidants. This review features various studies to provide an overview on how Carica papaya help counteract oxidative stress via various mechanisms of action closely related to its antioxidant properties and eventually improving the management of various oxidative stress-related health conditions. Carica papaya is a topical plant species discovered to contain high amounts of natural antioxidants that can usually be found in their leaves, fruits and seeds. It contains various chemical compounds demonstrate significant antioxidant properties including caffeic acid, myricetin, rutin, quercetin, α-tocopherol, papain, benzyl isothiocyanate (BiTC), and kaempferol. Therefore, it can counteract pro-oxidants via a number of signaling pathways that either promote the expression of antioxidant enzymes or reduce ROS production. These signaling pathways activate the antioxidant defense mechanisms that protect the body against both intrinsic and extrinsic oxidative stress. To conclude, Carica papaya can be incorporated into medications or supplements to help manage the health conditions driven by oxidative stress and further studies are needed to investigate the potential of its chemical components to manage various chronic diseases.


Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1449
Author(s):  
Cyril Quessada ◽  
Alexandra Bouscary ◽  
Frédérique René ◽  
Cristiana Valle ◽  
Alberto Ferri ◽  
...  

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by progressive and selective loss of motor neurons, amyotrophy and skeletal muscle paralysis usually leading to death due to respiratory failure. While generally considered an intrinsic motor neuron disease, data obtained in recent years, including our own, suggest that motor neuron protection is not sufficient to counter the disease. The dismantling of the neuromuscular junction is closely linked to chronic energy deficit found throughout the body. Metabolic (hypermetabolism and dyslipidemia) and mitochondrial alterations described in patients and murine models of ALS are associated with the development and progression of disease pathology and they appear long before motor neurons die. It is clear that these metabolic changes participate in the pathology of the disease. In this review, we summarize these changes seen throughout the course of the disease, and the subsequent impact of glucose–fatty acid oxidation imbalance on disease progression. We also highlight studies that show that correcting this loss of metabolic flexibility should now be considered a major goal for the treatment of ALS.


2005 ◽  
Vol 33 (2) ◽  
pp. 413-417 ◽  
Author(s):  
A.D. Metcalfe ◽  
M.W.J. Ferguson

Biomedical science has made major advances in understanding how cells grow into functioning tissue and the signalling mechanisms used to achieve this are slowly being dissected. Tissue engineering is the application of that knowledge to the building or repairing of organs, including skin, the largest organ in the body. Generally, engineered tissue is a combination of living cells and a supporting matrix. Besides serving as burn coverings, engineered skin substitutes can help patients with diabetic foot ulcers. Today, most of these ulcers are treated with an approach that includes antibiotics, glucose control, special shoes and frequent cleaning and bandaging. The results of such treatments are often disappointing and ineffectual, and scarring remains a major problem, mechanically, cosmetically and psychologically. Within our group we are attempting to address this by investigating novel approaches to skin tissue engineering. We are identifying novel therapeutic manipulations to improve the degree of integration between a tissue engineered dermal construct and the host by both molecular manipulation of growth factors but also by understanding and harnessing mechanisms of regenerative biology. For the purpose of this summary, we will concentrate primarily on the latter of these two approaches in that we have identified a novel mouse mutant that completely and perfectly regenerates skin and cartilaginous components following ear injury. This experimental animal will allow us to characterize not only novel genes involved in the regeneration process but also to utilize cells from such animals in artificial skin equivalents to assess their behaviour compared with normal cells. This approach should allow us to create a tissue-engineered substitute, which more closely resembles the normal regional microanatomy and physiology of the skin, allowing better integration to the host with minimal or no scarring.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Shanta Pandian ◽  
Kamal Narayan Arya ◽  
Dharmendra Kumar

Background. Balance and functional abilities are controlled by both sides of the body. The role of nonparetic side has never been explored for such skills.Objective. The objective of the present study was to examine the effect of a motor therapy program primarily involving the nonparetic side on balance and function in chronic stroke.Method. A randomized controlled, double blinded trial was conducted on 39 poststroke hemiparetic subjects (21, men; mean age, 42 years; mean poststroke duration, 13 months). They were randomly divided into the experimental group(n=20)and control group(n=19). The participants received either motor therapy focusing on the nonparetic side along with the conventional program or conventional program alone for 8 weeks (3 session/week, 60 minutes each). The balance ability was assessed using Berg Balance Scale (BBS) and Functional Reach Test (FRT) while the functional performance was measured by Barthel Index (BI).Result. After intervention, the experimental group exhibited significant(P<0.05)change on BBS (5.65 versus 2.52) and BI (12.75 versus 2.16) scores in comparison to the control group.Conclusion. The motor therapy program incorporating the nonparetic side along with the affected side was found to be effective in enhancing balance and function in stroke.


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