According to the Centers for Disease Control (CDC), Traumatic Brain Injury (TBI) is the world’s leading major cause of death.[1] It was said that the peripheral nervous system (PNS) and central nervous system (CNS) injuries may result to temporary or permanent impairments of cognitive and physical functions.[1, 2] To repair these injuries is to rely on the ability to gain back the appropriate neuronal connectivity.[3] These functional impairments can be repaired with neural transplantation, such as allografts and autografts.[4] Autografts consist of tissue repair using autologous cell/tissue for transplantation.[5] However, the flaw for autografts is the loss of function at the donor site leading to multiple surgeries.[6] On top that, the materials can be limited and at times when patient still suffer from neuroma pain.[6] Allografts on the other hand, utilise tissue from the same species but different subject.[5] However, the disadvantages for allografts are the risk of disease transfer and the potential to cause an immune reaction.[5] Due to the disadvantages faced by autografts and allografts, biodegradable three- dimensional nanofibrous scaffold in tissue engineering (TE) is introduced for tissue regeneration as they show promising regenerative outcomes.[2, 6, 7]. To promote neural regeneration, the nanofibrous scaffold is design to provide the mechanical support for the transplanted cells, guidance cues for neurites and for the delivery of biomolecules.[2] Besides that, to promote neural regeneration the nanofibrous scaffolds shows 2 features that is well suited for CNS tissue engineering applications.[8] These two features are the highly porous structure, morphology and architecture of the fibre.[8] The highly porous struct... ... middle of paper ... ...trospinning are able to control the morphology and fibre diameter of the fibre providing the support that is able to mimic the ECM.[16] The following dissertation will discuss on the fabrication of electrospun PCL nanofibre for tissue regeneration. This is to address the limitation faced by current TE scaffold. As there are insufficient focus on the production of PCL nanofibres with surface morphology and even fibre diameters for the use for tissue regeneration. On top of that, biopolymer such as PCL has the ability to degrade over time and still produce the porous structure desired by the nanofibre.[17] Hence, to control the fabrication of PCL nanofibre, the effects of the electrospun parameters is studied in the following dissertation. On top of that, the dissertation will investigate the fabrication of electrospun PCL nanofibre scaffolds for tissue regeneration.
The brain is a complicated organ, containing an estimated 100 billion neurons and around 1,000 to 10,000 synapses for each of those neurons (1). This organ has the great responsibility of not only controlling and regulating the functions of the body but also sensing and perceiving the world around it. In humans, it is what we believe makes us the highly adaptive and intelligent organisms that we are, as well as give us our individuality. But with so many parts and connections to it, what happens when the brain's delicate circuitry is disrupted? We've all heard of brain damage, and its horrible results, whether is a news report on TV or science books. It seems that with trauma, disruption of blood supply, and disease; neurons and their connections could be destroyed and the organism's behavior exceedingly affected. Yet I've read about how people have overcome tremendous damage to their brains and gone on to function with very minimal handicaps.
Reconstruction using donor tissues will have two surgical sites and scars. Recovery takes a bit longer. But, they look more natural than implants. There is also no worries about implant ruptures or the need for future
...eal or repair themselves, but after a breakthrough in Spinal cord research, done on a rat, it was discovered that the spinal cord “can support the development of transplanted cells”. Several anesthetised rats were given spinal cord injuries and after about two weeks, scientists transplanted human nerve stem cells into their injured spinal cords. Three months after the rats were injected with the human nerve stem cells, the scientists found that some of the stem cells had developed into support cells instead of nerve cells, yet some had developed into mature nerve cells. After about six months, the scientists discovered to their disbelief not only did the human stem cells survive in the rats’ spinal cords, but they underwent mitosis at least twice, and there were three times the amount of human stem cells found in the rats than the amount that was injected initially.
Two treatment types are being studied for spinal cord injury: injection of an antagonist of the ATP-sensitive receptor P2X7 and transplantation of human embryonic stem cell derived oligodendrocyte progenitor cells. In the spinal cord, ATP can act as an excitatory neurotransmitter (Domercq et al,. 2009). ATP is released in excess for six hours after the initial damage. Most tissue damage happens after the main injury occurs, so finding a treatment that will slow the secondary injury down is a main interest for clinical treatment studies. Injecting a P2X7 antagonist that is sensitive to ATP into the region of the spinal cord that has been damaged has been found to slow down secondary injury (Peng et al., 2009). Also, demyelination of neurons can be found after spinal cord injury. Transplanting human embryonic stem cell derived oligodendrocyte progenitor cells into the damaged tissue has shown to help with remyelinating the neurons. Th...
...ty of these scaffolds in skin tissue engineering as most of the skin cells like fibroblasts, keratinocytes etc., are smaller in size when compared to the pores. Therefore cells migrate and proliferate freely on these scaffolds along with the production of extracellular matrix. Furthermore, large and interconnected porous network facilities the diffusion of nutrients together with efficient gaseous exchange and is important for cell survival. As we run the in vitro experiments in the presence of media it is important to understand the variation in the pore size and diameter when the scaffold absorbs water or any other liquid. Pore size of the gelatin cryogel was in the range of 10-100 µm in swollen state. As evident from the results obtained even after the absorption of water the matrices have large pore-size that favours effective cell proliferation and migration.
Organ development is the moving of an organ beginning with one body then onto the following or from an advocate site to another range on the individual's own specific body, to supplant the recipient's hurt or missing organ. Organs and tissues that are transplanted inside the same individual's body are called autografts. Transplants that are starting late performed among two topics of the same species are called allografts.
Around 8,000 people die every year waiting for an organ transplant because there is a shortage of human organs available. Xenotransplantation, the process of grafting or transplanting cells, tissue, or organs between two different species (non- human to human), could be a solution to increasing the donor list. Xenotransplants have been performed before, but with new technology, like regenerative medicine and stem cells research, emerging during the same time period, much of the attention and the funding support went to the other research because of the more promising future and less ethical problems (Cozzi 288). Some of the general public, scientists, and government agencies believe that with xenotransplants having so many ethical problems
After an injury, thanks to the mechanism of plasticity, reorganization of the sensory and motor systems occurs in multiple levels including the spinal cord, brainstem, thalamus and cortex (Chen, Cohen & Hallett, 2002). Furthermore, if the injury happens at a young age, the reorganization is even more extensive and determines a better recovery. Neuroplasticity and neurogenesis can still happen in adults, but they are less efficient and fast than in children. What happens after an hemispherectomy dramatically proves the resilience of the brain to extensive damage (Villablanca & Hovda, 2000). For example, “when an entire cerebral hemisphere is removed early postnatally in cats, the rest of the brain continues to grow and, in adulthood, the animals do not appear different from normal litter mates” (Villablanca & Hovda, 2000). Many experiments have been carried out to understand more about the consequences of hemispherectomies on the functional structure of the brain. Holloway, Gadian, Vargha-Khadem, Porter, Boyd and Connelly (2000) have studied the sensorimotor functions of the hemiplegic hand after hemispherectomy, and the results proved that all the patients with congenital disease had residual sensory function in the hand contralateral to the hemispherectomized side, while half of the patients had residual motor functions. In patients with acquired disease, 66% had residual sensory function while none
Many people say that everyone in the world has a twin. Today, science and technology has the ability to make this myth reality through the process of cloning. I am strongly against cloning for many reasons. People should not utilize cloning because it would destroy individuality and uniqueness, cause overpopulation, animal cruelty, it is against morals and ethics, and it violates many religious beliefs.
the brain where damage has occurred, producing the many types of neurons needed to replace the
An allograft is either bone, cartilage, tissue, ligament, tendon or any section of the skin that is donated from another person that is deceased. Allografts do contain osteoconductive scaffolds with minimal osteoinductive factors. A disadvantage of Allografts is the risk of bacterial contamination or the possibility of viral transmission diseases such as hepatitis and human immunodeficiency5. Jorgenson et al.6 Conducted a prospective analysis in lumbar fusion of allografts versus autografts in the same patient and concluded that an ethylene oxide-treated allograft is inferior to an autograft and should not be used for posterior lumbar fusions(Level II). Further, An et al.7conducted a prospective comparison of autografts and allografts for adult posterolateral lumbar spinal fusion and reported that autografts resulted in significantly greater bone density, followed by the mixture of autografts and allografts, frozen allografts, and freeze-dried allografts (Level II). These reports indicate that allografts alone were not able to achieve a sufficient fusion rate for posterior spinal fusion in the adult
I initially wanted to focus on the nerves located in the spinal cord so those who are paralyzed are not wheelchair bound for the rest of their lives. I soon realized if nerve pathways in the brain could be restored, then the same process could be applied to nerves in the spine. The reason why prosthetics are able to work is due to the fact that neural pathways in our peripheral nervous system (PNS), nerves that connect our limbs to the CNS, are able to regenerate on their own. These neurons are covered with Schwann cells that facilitate the regeneration of the axon, the part of the cell responsible for transmitting signals. Certain proteins located in the CNS, astrocytes and
SILICONE - A TRENDING BIOMATERIAL R.PERUMAL SAMI,rperumalsamirdftijk@gmail.com,C.LALITHA LAKSHMI,lalithamufc@gmail.com, T.LAKSHMI,nandhini2013@gmail.com . ABSTRACT: Silicone polymers are of relatively recent invention and commercial production was started in the 1940's. Shortly thereafter it was found that glass surfaces treated with silicone fluid delayed the clotting of blood. By the mid-1950s medical applications of silicones had greatly increased and many studies of the biological properties of these materials were undertaken. Silicones are one of the most widely used and one of the most studied of all artificial materials for medical applications and no discussion of biomaterials is complete without their inclusion.
1. What is the difference between a. and a. INTRODUCTION: The demands of artificial organs have been increasing in recent years. In the past, there was no modern medical equipment; also, if someone lost part of his body parts, they would probably die. These days with the advancement of technology, a person can live for a longer period.
"Artificial" tissue is grown-up from the patient's personal cells. However, when the harm is so dangerous that it is unbearable to use the patient's own cells, artificial tissue cells are grown. The trouble is in discovery a scaffold that the cells can grow and organize on. The features of the support must be that it is biocompatible; cells can adhere to the support, mechanically durable and recyclable. One successful support is a copolymer of lactic acid and glycolic acid.