4. Discussion Tissue engineering has become a novel technology to regenerate damaged tissues by combining biomaterials, cells and bioactive moieties such as the growth factors [41,42]. Myocardial tissue engineering has gained a special attention of research within the field of tissue engineering due to its clinical feasibility, and inefficiency of other methods for repairing infracted heart muscle. [3,8,43-45]. Natural and synthetic polymers have individual strengths and belnding them could produce scaffolds with complementary properties. Natural polymers possess high cytotropism due to good hydrophilicity with abundance of surface cell-recognition sites; however poor mechanical properties and fast degradation rate are the major drawbacks of these polymers. In contrast, synthetic polymers have desired mechanical properties and suffer from low hydrophilicity and lack functional groups within their structure which hinder cell affinity towards them. Recently electrospun scaffolds composed of a variety of natural and synthetic polymers have been used for myocardial tissue engineering [9,10,17,18,20,32,46,47]. Since highly stiff substrates prevent the contractile properties of cardiac cells, relatively elastic scaffolds could be beneficial to provide a suitable environment for regeneration of the myocardial tissue [14]. PEUU is a biodegradable, biocompatible and elastic polymer with suitable mechanical properties to better mimic the native myocardium. Therefore during this study, we synthesized PEUU and utilized PEUU for the fabrication of nanofibrous scaffolds by electrospinning. The presences of urethane, urea and amide groups in the structure of synthesized PEUU were demonstrated by FTIR and that the results confirmed that the cha... ... middle of paper ... ...us scaffolds were fabricated with weight ratios of 100:0, 50:50 and 70:30 by electrospinning process. Results of characterization demonstrated the appropriate structure of the synthesized PEUU. Incorporation of gelatin within PEUU produced composite nanofibers with smaller fiber diameters, increased hydrophilicity and degradation rate. Following the biodegradation study, PEUU/G 70:30 were found more suitable than the PEUU/G 50:50 scaffolds for performing cytocompatibility studies. The anisotropic properties of myocardium were mimicked by fabrication of aligned nanofibers. Mechanical measurement and DMA studies showed anisotropic properties of aligned nanofibrous scaffolds in both wet and dry condition. In vitro cell culture study showed more proliferation and integration of cardiomyocytes on PEUU/G 70:30 nanofibrous scaffolds compared to that on pure PEUU scaffolds.
In recent years, the type of futuristic technology that we see in movies is finally coming to life through this idea of superhuman abilities in bionic limbs that use artificial intelligence. The new developments and breakthroughs in prosthetics, changed what we thought would only be fictional into reality.
Pinto Reis C., Neufeld RJ., Ribeiro AJ., & Veiga F., 2006. Nanoencapsulation I. Method for preparation of drug-loaded polymeric nanoparticles. Nanomedicine: Nanotechnology, Biology and Medicine, 2, 9-21
Coronary artery disease is a heart disease characterized by narrow arteries and restricted blood flow in arteries and is the major cause of morbidity and mortality globally.[1] According to WHO estimation, 6.8% in men and 5.3% in women are affected globally.[2-4] Cardiovascular disease account for 29% of all deaths in Canada; of all the cardiovascular death, 54% and 23% was due to ischemic heart disease and heart attack, respectively. The total costs for heart disease and stroke were more than $20.9 billion every year. [5,6] With more than 1 artery impacted, multivessel coronary artery disease is more complex and more likely accompanied by other comorbidities including diabetes or high blood pressure; multivessel coronary artery disease usually is more difficult to deal with, has worse prognosis and cost more compared with single coronary artery disease. [7]
The development of the artificial heart began in the early 1950’s. The initial prototype, developed in 1970’s by the artificial developmental staff at the University of Utah, allowed 50 hours of sustained life in a sheep. Although this was called a success, the implantation of the artificial heart left the sheep in a weakened state. It wasn’t until late 1970’s and the early 1980’s where the improvement of the artificial heart actually received attention as a possible alternative to a heart transplant. The remodeled product of the early 1970’s did more than just the 50 hours of sustained life; it enabled the cow to live longer and to live a relatively normal life, with the exception of a machine attached to the animal.
Brendan Maher, in his article “How to Build a Heart” discusses doctor’s and engineer’s research and experimentation into the field of regenerative medicine. Maher talks about several different researchers in this fields. One is Doris Taylor, the director of regenerative medicine at the Texas Heart Institute in Houston. Her job includes harvesting organs such as hearts and lungs and re-engineering them starting with the cells. She attempts to bring the back to life in order to be used for people who are on transplant waiting lists. She hopes to be able to make the number of people waiting for transplants diminish with her research but it is a very difficult process. Maher says that researchers have had some successes when it comes to rebuilding organs but only with simples ones such as a bladder. A heart is much more complicated and requires many more cells to do all the functions it needs to. New organs have to be able to do several things in order for them to be used in humans that are still alive. They need to be sterile, able to grow, able to repair themselves, and work. Taylor has led some of the first successful experiments to build rat hearts and is hopeful of a good outcome with tissue rebuilding and engineering. Scientists have been able to make beating heart cells in a petri dish but the main issue now is developing a scaffold for these cells so that they can form in three dimension. Harold Ott, a surgeon from Massachusetts General Hospital and studied under Taylor, has a method that he developed while training. Detergent is pumped into a glass chamber where a heart is suspended and this detergent strips away everything except a layer of collagen, laminins, and other proteins. The hard part according to Ott is making s...
Children grow up watching movies such as Star Wars as well as Gattaca that contain the idea of cloning which usually depicts that society is on the brink of war or something awful is in the midsts but, with todays technology the sci-fi nature of cloning is actually possible. The science of cloning obligates the scientific community to boil the subject down into the basic category of morality pertaining towards cloning both humans as well as animals. While therapeutic cloning does have its moral disagreements towards the use of using the stem cells of humans to medically benefit those with “incomplete” sets of DNA, the benefits of therapeutic cloning outweigh the disagreements indubitably due to the fact that it extends the quality of life for humans.
When asked how he feels about the advancement of science to places that were once notions to be the job of the creator, Dr. Martin Luther King replies by saying, “Cowardice asks is it safe? Expedience asks is it political? Vanity asks is it popular? But the conscience asks is it right?”
These kinds of polymers have both some advantages and disadvantages. Although they are bioactive and biodegradable and provide high comppressive strength, Degradation of such polymers leads to undesired tissue response due to producing acid formation in degradation process. Metallic scaffolds are another method for bone repair and regenaration. They provide high compressive strength and enormous permanent strength. Metallic scaffolds are mainly made of titanium and talium metals. The main disadvantages of metallic scaffolds are not biodegradable and also discharge metal ions. Recent studies in metallic scaffolds mainly focus on biodegradable materials which can be used improve bioactivity of metals such as titanium.
... the usage of bioresorbable scaffold involves by selecting certain phenotype of cell and implants it on permeable substance before being implanted to the pulmonary position. The scaffold is presume to degenerate as the cells grow. The last approach involves constructing a mold for leaflets similar to the aortic shape using the collagen constructs (Vesely 2005).
A Comparison of the Chemical Structures and Production Methods of Silk and Artificial Silk Abstract Despite their seemingly similar exteriors, the chemical structures and production methods of natural silk and the artificial silks, rayon and nylon are quite different. Silk yarn, extracted from the.. from the cocoon of the Bombyx mori moth, is made up of fibroin molecules with beta-pleated. sheet of secondary structures. The fibroin molecules consist of crystalline fibers constructed of regularly paralleled, unfolded polypeptide chains of polyglycylalanine mixed with an amorphous. part.
Since human recognize the material, biomaterials have had initial development. As early as 3500 BC, the ancient Egyptians used sutures made of cotton fiber or horse hair, and in 16th century gold plate was used to repair jaw bone and ceramic materials were used to make dedendum, and so on. With the development of medicine and materials science, especially the success of the research and development of new materials, such as the rapid development of polymer materials in the 1940s provides a great opportunity for the research and application of biomaterials. It could be said that in addition to the brain and most
The future for the total artificial heart with respect to using polyurethanes comes in the form of thermoplastic polyurethane (TPU), also known as polyurethane elastomers that have molecular structures similar to that of human proteins. TPUs have slower protein absorption (protein absorption is the beginning of the blood clotting process) this makes TPUs ideal candidates in the manufacturing of the total artificial heart because it provides more adhesive strength and mimics certain elements within the body. Hence, biomedical polyurethanes can lead the way to eliminate some acute health challenges that the total artificial heart currently faces. By virtue of their range of properties, polyurethanes and their new applications will continue to play an important role in the future of the total artificial heart.
The field of bioprinting, using 3D printing technology for producing live cells with extreme accuracy, could be the answer to many of the problems we as humans face in the medical field. It could be the end to organ waiting lists and an alternative for organ transplants. In 3D printing technology lies the potential to replace the testing of new drugs on animals. However, the idea of applying 3 dimensional printing to the health industry is still quite new and yet to have a major impact. Manufacturing working 3D organs remains an enormous challenge, but in theory could solve major issues present today.
Nano materials have gained great attention with their high surface area and great reactivity. Nano scale synthesis is achieved by two ways: a top down approach (take a larger particles and scale them down), a bottom up (normally chemical synthesis). Because of the abundance of cellulose, a top down approach was selected, although; bottom-up approaches yield a more desirable product with the least amount of defects. The microcrystalline cellulose (Iα, Iβ) is then digested with sulfuric acid this specifically targets the amorphous regions breaking the polymer chain into oligomers on to the nano scale [5,8]. Depending on the concentration of acid will either yield cellulose nano fibrils (CNF’s) or, cellulose nano crystals (CNC’s). CNF’s though still on the micro scale in length are defined as their size in diameter of which ranges from 4-7nm in width [8,14]. Lyophilization aides in the self-assembly behavior as the cellulose begins to align chirally. There are four chiral carbons on each monomer unit of the nanocellulose (2,3,4,5) [1718], which align with chiral carbons from adjacent nanocellulose polymers. Due to the chiral, pneumatic alignment of the nanocellulose during sublimation, a uniform dispersion of cellulose is obtained throughout the polymer composites
The field of regenerative medicine encompasses numerous strategies, including the use of materials and de novo generated cells, as well as various combinations thereof, to take the place of missing tissue, effectively replacing it both structurally and functionally, or to contribute to tissue healing[29]