Tissue Engineering Scaffold

Tissue engineering is an emerging interdisciplinary field that uses principles from engineering, biology and chemistry in an effort towards tissue regeneration. The main draw of tissue engineering is the regeneration of a patient’s own tissues and organs free from low biofunctionality and poor biocompatibility and serious immune rejection. As medical care continues to improve and life expectancy continues to grow, organ shortages become more problematic.(Manufacturing living things) According to organdonor.gov, a patient is added to the waiting list every 10 minutes and an average of 18 people die everyday waiting for an organ donation. The “nirvana” of tissue engineering is to replace the need for organ donation altogether. This could be achieved using scaffolding from

Rather than relying on surgical methods meant to replace these tissues, scientists are now beginning focus on new methods that actually allow the heart to repair and replace damaged tissue. In the June 29, 2006 edition of the journal entitled, Nature, Dr. Kathryn Ivey of the Gladstone Institute of Cardiovascular Disease explains, “the ability of circulating cells to produce factors that are sufficient to invoke cell survival or repair responses in damaged heart cells” remains a primary objective of research cardiologists. By manipulating synthetic compounds meant to catalyze the regeneration of tissue, the new experimental method of repairing heart muscles may be able to abandon surgical procedures altogether. While the vast majority of attention is being spent on the ability to use stem cell therapy to repair congenital heart defects, some scientists are exploring alternative possibilities in organisms like the

After a heart attack, the heart is unable to regenerate cardiac muscle cells known as myocytes which diminishes the heart’s pump function. The heart tries to heal itself by changing the damaged or dead heart muscle cells into scar tissue. However, the scar tissue cannot function as a muscle so it does not contribute to the cardiac contractile force. Overtime, this leads to a greater burden on the remaining viable heart muscle which eventually leads to heart failure. Current treatments such as autologous grafting and commercially available fillers incur donor-site morbidity and volume loss over time. Other transplantation therapies do not directly address the loss of cardiac myocytes, which leads to the drive for more research in cardiac regeneration.

As stated earlier, Gene therapy is the process in utilizing specific strategies to help change the expression of a mutated gene, while cell therapy injects healthy cells into a patient’s body for treatment of a particular disease. In the experiment, a lentiviral Egfp expression vector was custom made. The virus was created through cotransfection of HEK293T cells. The virus was then titrated by the Egfp expression three days after the transduction of the HeLa cells. The researchers injected the virus LV-Egfp into an organ explant culture to test the usefulness of gene transfer. To test the usefulness of cell therapy, researchers used freshly isolated neonatal rat ventricular cardiomyocytes were placed over the day old organ explant culture. The spontaneous beating was measured through the microelectrode measurements (den Haan et al.,

INTRODUCTION The heart is made of specialized tissue known as cardiac muscle. Cardiac muscle is made of myocardial cells which can be further divided into autorhythmic and contractile cells. The autorhythmic cells are composed of sinoatrial (SA) nodes and atrioventricular (AV) nodes. These nodes contain pacemaker cells that control heart rate by producing pacemaker potentials.

First and foremost, ischaemic heart disease is a condition in which blood flow and oxygen is restricted in the heart which can lead to heart attacks. When cardiac muscles are starved of oxygen and nutrients, they will die resulting in scarring since cardiac muscles are one of the least regenerative tissues in the human body. Scarring can eventually lead to complications, as scar tissues do not contract or pump as well as healthy cardiac muscle tissues. Dr Chong and his team has seek to treat this damage by implanting cardiomyocytes derived from human embryonic stem cells into the damaged area of the heart.

For my regenerative medicine report I chose 3D organ printing, also called 3D Bioprinting. More specifically, I focused on the 3D printing for Kidneys. 3D printing of organs works by using stem cells to create tissue that can be used to fix a part of an organ, or many tissues that can create a whole organ. (ed.ted.com) The printers, in collaboration with computer-assisted design, would print out ultra thin layers of tissue to be layered on top of one another to form organs. (asme.org) There are also 3D printers that were made that can print stem cells. (livescience.com) This way, instead of extracting totipotent embryonic stem cells, or having to settle for pluripotent adult ones, there can be stem cells that are still totipotent

The usage of cardiac-derived cells are considered as the most potential autologous cell source for cardiac repair as in a research done by Tang et al. (2013), there is a reduction in the size of the scar but has no significant improvement in cardiac functions as measured using left ventricular ejection function (LVEF).

It is nearly impossible for me to grasp the idea of what being truly disabled is like. There are far too many people around the world living day by day, with major struggles to accomplish the basic tasks of life because of their affliction. Through volunteering this past summer at Hartford Hospital, serving meals to destitute people at the South Park Inn Homeless Shelter and meeting disabled veterans at a Rangers Lead the Way fundraiser, I have seen first-hand, some of the problems and challenges of people with disability. Through these experiences and the insight gained from them, I believe that I am on a quest to enable the disabled around the world.

The worldwide incidence of bone disorders and conditions has trended steeply upward and is expected to double by 2020, especially in populations where aging is coupled with increased obesity and poor physical activity. Engineered bone tissue has been viewed as a potential alternative to the conventional use of bone grafts, due to their limitless supply and no disease transmission. However, bone tissue engineering practices have not proceeded to clinical practice due to several limitations or challenges. Bone tissue engineering aims to induce new functional bone regeneration via the synergistic combination of biomaterials, cells, and factor therapy. In this review, we discuss the fundamentals of bone tissue engineering, highlighting the current

A major goal of cardiac stem cell therapy is to transplant enough cells into the myocardium at the site of injury or infarction to maximize restoration of function. Several different approaches currently are being used to deliver stem cells. The intracoronary infusion involves the infusion of cells into a coronary artery, usually during a brief coronary occlusion produced by inflating a balloon at the tip of the catheter. This method of delivery offers several advantages: (1) it results in a much more uniform distribution of cells within the infarcted region, (2) it does not require specialized training or the purchase of specialized equipment, and (3) it is technically easier, more practical and widespread

Stem cell research into heart disease has shown some very promising results. The potential method in using stem cells to treat heart disease is by replacing all of the damaged heart tissue with healthy

The problem is after injury or myocardium infarction mammalian heart’s cardiomyocytes rarely divide which made it impossible for a resident cardiomyocyte proliferation. In result with this, an autologous stem-cell therapy is used. The first ever cell-based therapy done in an ischemic myocardium was the skeletal myoblast. Skeletal cells are myoblast and these can differentiate into myotubes and improve the ventricular function of the myocardium. However, injection of autologous skeletal myoblasts did not solve the problem and cannot fill the loss of cardiomyocytes resulting to an inefficiency. Another is the bone-marrow derived cells. In this field is where allogeneic transplantation takes place. A bone-marrow cells are taken from a willing and matched donor to the patient and these cells will be cultured and cultivated until it is ready for transplantation. It is proven to be effective and that these bone-marrow derived cells are progenitor cells that will regenerate cardiomyocytes in a mammalian

With development of genetically altered mice, there is intense interest in developing murine models to study mechanisms operative in cardiovascular disease. To study the effect of coronary artery occlusion and reperfusion on myocardium and the methods involved to perform such studies both acutely and chronically, Michael et al [64] developed the open chest mouse model using male FVB mice. LAD coronary artery was occluded permanently or for 30-60 min followed by reperfusion. It was suggested that, as compared with permanent occlusion there was a significant decrease in infarct size as a percentage of the area at risk in reperfusion. Infiltration of leukocytes into the ischemic region as well as contraction bands was found in re-perfused myocardium. With the help of this model the complex pathophysiology, area at risk, infarct size and cardiac function in mouse can be assessed. This model allows the induction of myocardial infarctions of varying degrees and long-term survival of mouse. It also allows studying the effect of the absence or over-expression of a gene product in the progression of injury and inflammation in ischemic reperfusion in a transgenic mouse.

Ever since I was a toddler, I’ve demonstrated my desire to help others. If there was a fellow toddler crying, I would share my toys in an attempt to calm them down. As I grew up, my desire to help others expanded from sharing toys to tutoring other students or providing service to the surrounding community. By the time college applications rolled around, I had also developed a love of science, in addition to my desire to be helpful. I found myself scanning the list majors that different colleges had to offer, eventually stumbling upon biomedical engineering. Initially, I knew very little about the field, assuming they mostly worked with prosthetics. However, as I did more research into the major, I learned biomedical engineers create devices beyond prosthetics, such as machines to replace a working heart or more efficient medical equipment. This major also allowed for the flexibility of attending medical school, another career aspiration I have had since I was little. So without hesitation, I was able to put biomedical engineering as my intended major on my college applications. It was not until I came to the University of Michigan that my confidence in my major began to waver. I asked myself, “Do I really know what biomedical engineers do? What concentration should I pursue if I also hope to attend medical school?” These were questions that floated in my mind until I interviewed Professor Zhen Xu Ph.D.