Tackling Ischemic Reperfusion Injury With the Aid of Stem Cells and Tissue Engineering

Ischemia is a severe condition in which blood supply, including oxygen (O), to organs and tissues is interrupted and reduced. This is usually due to a clog or blockage in the arteries that feed the affected organ. Reinstatement of blood flow is essential to salvage ischemic tissues, restoring O, and nutrient supply. However, reperfusion itself may lead to major adverse consequences. Ischemia-reperfusion injury is often prompted by the local and systemic inflammatory reaction, as well as oxidative stress, and contributes to organ and tissue damage. In addition, the duration and consecutive ischemia-reperfusion cycles are related to the severity of the damage and could lead to chronic wounds. Clinical pathophysiological conditions associated with reperfusion events, including stroke, myocardial infarction, wounds, lung, renal, liver, and intestinal damage or failure, are concomitant in due process with a disability, morbidity, and mortality. Consequently, preventive or palliative therapies for this injury are in demand. Tissue engineering offers a promising toolset to tackle ischemia-reperfusion injuries. It devises tissue-mimetics by using the following: (1) the unique therapeutic features of stem cells, i.e., self-renewal, differentiability, anti-inflammatory, and immunosuppressants effects; (2) growth factors to drive cell growth, and development; (3) functional biomaterials, to provide defined microarchitecture for cell-cell interactions; (4) bioprocess design tools to emulate the macroscopic environment that interacts with tissues. This strategy allows the production of cell therapeutics capable of addressing ischemia-reperfusion injury (IRI). In addition, it allows the development of physiological-tissue-mimetics to study this condition or to assess the effect of drugs. Thus, it provides a sound platform for a better understanding of the reperfusion condition. This review article presents a synopsis and discusses tissue engineering applications available to treat various types of ischemia-reperfusions, ultimately aiming to highlight possible therapies and to bring closer the gap between preclinical and clinical settings

Stem cells and tissue engineering in new tooth production

Tkivni inženjering matičnih stanica nova je disciplina na području stomatologije čija je težnja pronaći postupak kojim bi se umjetnim putem mogao stvoriti zub koji bi kao nadomjestak izgubljenom zubu u potpunosti zadovoljio sve estetske i funkcionalne kriterije. Matične stanice su stanice čija su dva svojstva ključna za upotrebu u tkivnom inženjeringu, a to su svojstvo neograničenog samoobnavljanja i diferencijacije. Postoje dva tipa matičnih stanica embrionalne izolirane iz blastociste embrija i odrasle matične stanice. Iako embrionalne stanice imaju puno veći diferencijacijski potencijal, njihova klinička upotreba nije moguća. Adultne matične stanice moguće je izolirati iz različitih tkiva ljudskog organizma pa tako razlikujemo i pet tipova adultnih matičnih stanica izoliranih iz dentalnih tkiva. Sam proces tkivnog inženjeringa osmišljen je kao oponašanje procesa organogeneze kroz epitelno-mezenhimalnu interakciju. Da bi se proizveo zubni zametak, neophodna je interakcija epitelnih i mezenhimalnih stanica uz uvjet da jedan od ta dva tipa stanica ima mogućnost inducirati nastajanje dentalnih tkiva, a drugi tip stanica na taj poticaj odgovoriti. Kroz istraživanja je pokazano da se pomoću embrionalnih stanica može proizvesti zub, no klinička praksa traži nova rješenja pa su do sada provedena ispitivanja s matičnim stanicama koštane srži, ali također i sa stanicama gingivalnog epitela, te keratinocita kao zamjene za epitelnu komponentu. Prekretnicu je također izazvalo otkriće induciranih pluripotentnih matičnih stanica čiji je diferencijacijski potencijal jednak embrionalnim matičnim stanicama.Stem cells tissue engineering is a new discipline in dentistry that aims to find the way to produce an artificial tooth as a perfect aesthetic and functional replacement for a lost tooth. Stem cells have two characteristics important for tissue engineering and these are self-renewal and differentiation. There are two types of stem cells: embryonal isolated from embryo blastocyst and adult stem cells. Although embryonal stem cells show better differentiation potential, their clinical use is not possible. It is possible to isolate adult stem cells from different human tissues, so there are five different types of dental adult stem cells. The tissue engineering process is actually the mimic of organogenesis through the epithelial mesenchymal interaction. To produce a dental germ, an interaction is necessary with the condition that one cell type can induce dental tissue production and second can respond to that initial signal. It has been shown that it is possible to produce a tooth using embryonal stem cells, but it is important to find new cell sources for clinical use. Experiments were made using bone narrow stem cells, gingival epithel cells, keratinocites as replacement for epithelial component. The big milestone was the finding of induced pluripotent stem cells that have differentiation potential just like embryonal cells

Dental Pulp Stem Cells and Tissue Engineering Strategies for Clinical Application on Odontoiatric Field

Recent advances in tissue engineering have drawn scientists to test the possibility of tooth engineering and regeneration. Tooth regeneration is normally referred to as the regeneration of the entire tooth or root that can be integrated into the jaw bone. This technology is still at its infancy and when it matures, it may be used to restore missing teeth and replace artificial dental implants When the tooth is damaged but still in a reparable condition, regeneration of parts of the tooth structure can prevent or delay the loss of the whole tooth. To engineer and regenerate a whole tooth, the cell source, tissue engineering strategies and specific scaffolds needed to be correct choose. Indeed, for example, to repair partly lost tooth tissues such as PDL, dentin, and pulp, one or two particular types of dental stem cells may be sufficient to fulfill the need. In light of such considerations, aim of the present chapter is to define the main strategies to isolate dental pulp stem cells, their characterisation and differentiation, tissue enngineering strategies and clinical applications for the creation of artificial tissue useful in odontoiatric field

Biodegradable Scaffolds for Gastric Tissue Regeneration

Tissue engineering has been viewed as a valid approach toward the partial or total replacement of defective tissues and organs. Recent advances in nanotechnology have made it possible to develop biocompatible materials at the micro- and nano-scales to be used as scaffolds for cellular growth and regeneration of defective tissues. Gastric mucosal lining is an example of soft tissues that are highly susceptible to damage due to various reasons including cancer or ulcer development. Current therapeutic approaches to these diseases have some limitations. This chapter describes the basis for development of a novel modality combining nanotechnology, stem cells, and tissue engineering for the replacement of defective gastric tissues using synthetic biocompatible scaffolds. These microfibrous scaffolds are seeded with gastric stem cells, which are studied for their proliferation and differentiation into functional gastric mucous cells

Understanding Regenerative Medicine and Its Position in Healthcare

Abstract: Regenerative medicine is an emerging field of the healthcare industry that has the potential to treat a myriad of health conditions. Induced pluripotent stem cells, human embryonic stem cells, and tissue engineering are a few of the treatment methods that may be delivered by healthcare professionals in personalized medicine. Food and Drug Administration (FDA) approval is necessary within the United States before any of these treatment options are available. Specific cellular therapies are currently undergoing clinical trials and it may be years before approval is acquired. The National Institute of Health is proactively working to ensure that healthcare policies, costs, regulations, protocols, and provisions are implemented to ensure that risks are minimized in the case of FDA approval. Regenerative rehabilitation will improve traditional healthcare delivery, increasing health, function, and quality of life for patients with a variety of conditions

Regenerative medicine: current research and perspective in pediatric surgery

The field of regenerative medicine, encompassing several disciplines including stem cell biology and tissue engineering, continues to advance with the accumulating research on cell manipulation technologies, gene therapy and new materials. Recent progress in preclinical and clinical studies may transcend the boundaries of regenerative medicine from laboratory research towards clinical reality. However, for the ultimate goal to construct bioengineered transplantable organs, a number of issues still need to be addressed. In particular, engineering of elaborate tissues and organs requires a fine combination of different relevant aspects; not only the repopulation of multiple cell phenotypes in an appropriate distribution but also the adjustment of the host environmental factors such as vascularisation, innervation and immunomodulation. The aim of this review article is to provide an overview of the recent discoveries and development in stem cells and tissue engineering, which are inseparably interconnected. The current status of research on tissue stem cells and bioengineering, and the possibilities for application in specific organs relevant to paediatric surgery have been specifically focused and outlined

Células tronco e engenharia tecidual: revisão de literatura / Stem cells and tissue engineering: a literature review

Com avanço da ciência e tecnologia juntamente associada ao conhecimento do potencial regenerativo de células tronco e seu uso na medicina regenerativa, esse trabalho tem como objetivo informar e esclarecer sobre o que é engenharia tecidual e onde podemos aplicar células tronco para pesquisas, assim como quais tipos de células possuem e sua caracterização. Esse trabalho é uma revisão de literatura