Biology Project

Colleage of Engineering

Biology for engineers BIOL 341

FINAL COURSE PROJECT Instructor: Dr. Deena Ababneh

2021-2022

Heart biomedical applications Nada Ayed AlDosaru 2200005949 Fatimah Bsher Alnahdi 2200004600 Manar Muhammad AlHababi 2200004502 Khadijah Raed AlBasha 2200001510

Ventricular assist device (VAD) A ventricular assist device (VAD) — also known as a mechanical circulatory support device — is an implantable mechanical pump that helps pump blood from the lower chambers of your heart (the ventricles) to the rest of your body. A VAD is used in people who have weakened hearts or heart failure.

Although a VAD can be placed in the left, right or both ventricles of your heart, it is most frequently used in the left ventricle. When placed in the left ventricle it is called a left ventricular assist device (LVAD).

You may have a VAD implanted while you wait for a heart transplant or for your heart to become strong enough to effectively pump blood on its own. Your doctor may also recommend having a VAD implanted as a long-term treatment if you have heart failure and you're not a good candidate for a heart transplant.

The procedure to implant a VAD often requires open-heart surgery and has serious risks.

However, a VAD can be lifesaving if you have severe heart failure.

A left ventricular assist device (LVAD) is implanted in your chest. It helps pump blood from the left ventricle of your heart and on to the rest of your body. A control unit and battery pack are worn outside your body and are connected to the LVAD through a port in your skin. Also, it can be in the lower right heart chamber (right ventricular assist device, or RVAD) or both lower heart chambers (biventricular assist device, or BIVAD).

The doctor may recommend to have a VAD implanted if: I.

II.

III.

The patient waiting for a heart transplant. The patient may have a VAD implanted temporarily while he wait for a donor heart to become available. A VAD can keep blood pumping despite a diseased heart and will be removed when the new heart is implanted. It may also help improve the function of other organs in the body that may not be working properly and may improve other medical conditions. When a VAD is implanted while the patient waiting for a heart transplant, it's referred to as a "bridge to transplant."

The patient is not currently eligible for a heart transplant because of age or other conditions. A VAD may sometimes be implanted if the patient have heart failure, but he is not eligible for a heart transplant due to age or other medical conditions. This is called "destination therapy." In selected cases, the VAD may help improve the function of other organs that aren't working properly or improve other medical conditions that may be keeping him from being a candidate for a heart transplant. Generally, if the patient is older than age 65, he may not be eligible for heart transplantation. In that situation the VAD would be implanted as therapy for heart failure.

Heart's function can become normal again. If the heart failure is temporary, the doctor may recommend implanting a VAD until the heart is healthy enough to pump blood on its own again. This is referred to as "bridge to recovery."

Coronary Stents A coronary stent is a tiny, expandable mesh tube made of medical-grade stainless steel or cobalt alloy metal. It is an efficient invention that uses to open up a blood vessel that has a plaque blockage. Where materials collect in the walls of the arteries, such as fat, which leads to blockage and limit the amount of fresh blood that can reach the body.

A buildup of plaque in the arteries is a cause of coronary stent disease. The patients who suffer from narrowed arteries may notice warning symptoms, such as chest pain. If the artery is at risk of collapsing or becoming blocked again, doctors may recommend inserting a stent to keep it open.

There are several types of stents such as Bare-metal and Drug-Eluting Stents.

Bare-metal stents are tiny wire mesh tubes that help widen a clogged artery, but are not coated with a polymer or drugs to help prevent re-blockage of the artery. This type of stent may be used in patients who are allergic to either the polymer or drugs used in drug-eluting stents.

Drug-Eluting Stent is a bare-metal stent that has been coated with a polymer that gradually releases a drug over the time when re-blockage is most likely to happen. This helps reduce the chance of the artery becoming blocked again. There are two types of drug-eluting stents: 1-Permanent Polymer Drug-Eluting Stent. In this type of stent, the polymer stays on the stent permanently, even after all the drug has been released.

2-Bioabsorbable Polymer Drug-Eluting Stent. With this type of stent, the polymer and drug coating are fully absorbed by the body shortly after the drug has been fully released. This promotes better healing by eliminating long-term polymer exposure.

In short, coronary stenting can be safely performed in octogenarians with a high procedural success rate, low complication rate, and excellent 12-month outcome.

Total Artificial Heart (TAH) In some cases, heart failure occurs because of dysfunction of the ventricles, which lead to unable to pump the blood to the lungs and the body, and this is a big problem that needs to be solved, according to the difficulty to find a donor to perform a heart transplant, an artificial solution has been found, which is Total Artificial Heart (TAH).

Total Artificial Heart also called mechanical circulatory support is a device used to replace the damaged ventricles by this device. The device is include two parts left and right sides they simulate the left and right ventricles, also it has four valves to control blood flow as the normal heart, two valves are connected with the left and right atriums, and two with the major arteries, pulmonary artery and the aorta, then the (TAH) is connected to two wires that connected from the device inside the body to another device outside the body to charge and control it, now the (TAH) will be able work as the left and right ventricles and pump the blood to the lungs and the entire body.

For replace the ventricles with (TAH) a surgery is performed, where the patient is sleep and his heart is stopped and connect it to heart-lung bypass machine that works like the lungs, it works to load the blood with oxygen and return it to the heart during the replacement process. Only the ventricles will be removed, then the (TAH) will be placed The (TAH) is used only in cases of both left and right ventricles failure, but if the failure in just one side, then other device will be used, it also used for adults because it size is large and it doesn’t fit the children small bodies.

Heart-on-chip The heart-on-chip is a microfluidic chip for implanting microfluidics into a cell to create a microfluidic environment as it reproduces the mechanisms of the heart. Usually, made of a glass slide. Polydimethylsiloxane (PDMS) is mostly used as a polymeric material due to its desirable properties such as transparency and biocompatibility for the fabrication of microfluidic devices where on-chip core devices consist of several small chambers and microchannels printed on a layer of sealed polymer by bonding with another material. They are used for rapid drug testing and monitoring of heart cell interaction. Great care is taken to mimic the mechanisms of the heart in an artificial structure lined with live heart cells. Mechanical contractions, molecular transport, electrical activity, and specific responses to some pharmacological stimulus all have to be carefully designed and supervised in order to create a valuable model that simulates the main characteristics of the heart and is programmed to respond to continuous and discontinuous changes. The contraction movement is so important for the construction of a robust cardiac model that it is stimulated by a differentiated expansion pulse. To better understand how the chip works, cells are placed in a culture medium and within 13-15 days, muscle fibers (human induced stem cells) are formed. In addition, it stimulates beta adrenergic. In fact, adrenergic neurotransmitters are essential for regulating heart rate. As expected, they observed increased measured force and contraction speed after adding isoproterenol, known as adrenergic receptor agonists. And the cells inside the slide are stimulated by periodic mechanical stimulation to obtain better cell maturation. In the end, the research is continuing on the slide, but it has the potential for pharmaceutical and research applications, as it can reduce the cost. https://www.youtube.com/watch?v=5CgMoSJFtSQ&ab_channel=CNBioInnovations

resources 1.

Ventricular assist device (VAD) - Mayo Clinic. (2021). Retrieved 12 November 2021, from https://www.mayoclinic.org/tests-procedures/ventricular-assistdevice/about/pac-20384529

2.

Jason A. Cook, D. (2015). The total artificial heart. Retrieved 27 November 2021, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4703693/

3.

Metzger, M. (2021, June 21). Heart-on-chip | Technology review - Elveflow Microfluidics.

Elveflow. Retrieved November 27, 2021, from https://www.elveflow.com/microfluidicreviews/organs-on-chip-3d-cell-culture/heart-on-chip-microfluidic/

4.

Liu, H., Bolonduro, O. A., Hu, N., Ju, J., Rao, A. A., Duffy, B. M., Huang, Z., Black, L. D., & Timko, B. P. (2020). Heart-on-a-Chip Model with Integrated Extra- and Intracellular Bioelectronics for Monitoring Cardiac Electrophysiology under Acute Hypoxia. Heart-on-aChip Model with Integrated Extra- and Intracellular Bioelectronics for Monitoring Cardiac Electrophysiology, 20(4), 2585–2593. https://doi.org/10.1021/acs.nanolett.0c00076