Developments in nanotechnology and tissue engineering have provided promising ways to repair and replace damaged bone [3, 4]. Poly (sorbital sebacate adipate) (PSSA) is fully biodegradable, thermoplastic aliphatic polyester with biocompatibility and ecological safety. However, it has quite a few drawbacks, such as high elongations and very low thermal stability that prevent its larger commercial applications. The mechanical and thermal instability of PSSA elastomer prevents it from substituting the biodegradable nanomaterials in commercial products [3]. To overcome these drawbacks of PSSA, we have prepared PSSA nanocomposites with organically modified [4].
Human bone tissue is a nanocomposite with both organic and inorganic components. In particular, mineralized hydroxyapatite [Ca10(PO4)6(OH)2,] which is the main inorganic constituent in the bone extracellular matrix. Generally, a perfect tissue-engineered composite should assure several necessary criteria. It should be: biocompatible with biomimetic nanosurface structure and chemistry to minimize the local tissue response while maximizing cell growth and tissue integration; porous to allow cell passage and well-organized exchange of nutrients and wastes; biodegradable with a favorable degradation rate, allowing the composite to provide structural support for initial cell growth and then gradually degrade after new tissue formation; and possess appropriate mechanical properties to support tissue growth under native mechanical loads.[2,5–7].
Polymer nanocomposites are commonly defined as the combination of a polymeric matrix and fillers that have at least one dimension (i.e. length, width or In addition, PSSA/HAP composites have thickness) in the nanometer si...
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...tanding of their biological cell responses.
Here, we reported the synthesis of the SWCNTs-M-HAP/PSSA nanocomposites with varying amount of SWCNTs-M-HAP by hydrothermal insitu method. The friction coefficients of the SWCNTs-M-HAP composites were evaluated by UMT-2 friction tester. In particular, we discuss in detail the effect of several factors including SWCNTs-M-HAP content altering the mechanical, biological, thermal and structural properties of PSSA elastomer. For comparison, the friction coefficient of the pure PSSA elastomer was also investigated. We found that the addition of SWCNTs-M-HAP in composite can decrease the friction coefficient of the composite as compared with the pure PSSA. The friction coefficient of the composite gradually decreased with the increase of SWCNTs-M-HAP content in composite and increased with the increase in applied load.
Metal-on-metal hip resurfacing improves health related quality of life (1), post-operative function (2-5) and activity (6). Increasing number of hip resurfacing arthroplasties is being undertaken with good to excellent outcomes (4). Published reports show significant advantages of hip resurfacing as compared to total hip arthroplasty. Studies have shown improved gait parameters (7) and increased range of motion (8), but others have reported no difference when compared with standard hip arthroplasty (9, 10).
The are generally four kinds of substitute constituent utilized in THA that are metal-on-metal, metal-on-plastic, and ceramic on ceramic, ceramic on plastic. Types prosthesis utilized is reliant on the needs of patient and the procedure of the surgeon. All hip replacements allocate one thing in common: they contain a ball-and-socket joint. Which materials are utilized in the ball and in the socket, that jointly is shouted the “bearing” like a bearing in a car has the possible to alter the long-term durability of the combined replacement.
In orthopedic surgery, iliac bone graft which is commonly used for treatment nonunion or spinal fusion is contained multipotential stem cells or mesenchymal progenitor cells. These cells are found approximately 1 in 10,000 nucleated cells in the bone marrow. Friedenstein et al. (1970) reported that a rare population of cells was found by plastic-adherent ability (Friedenstein et al., 1970). These cells are capable of proliferation and mesenchymal lineages differentiation (Pittenger et al., 1999, Caplan, 1991). Unique antigens of MSCs (hMSCs) are controversy and the limited popularity of sorting cells techniques are not as widely used as gradient media in MSC isolation. Most MSC populations have been isolated by plastic adherent ability which is similar to that originally used by Friedenstein. Direct BM plating method is commonly used for cells from small animal (Lennon and Caplan, 2006, Nadri et al., 2007) but in human bone marrow, Density gradient centrifugation is the most commonly used method for isolating MSCs.
Alumina and zirconia ceramics have been widely used in orthopaedic hip replacements for the past 30 years. The advantage of using these was lower wear rates than those observed using polymers and metals. Because of the ionic bonds and chemical stability of ceramics, they are relatively biocompatible and therefore more preferable to use than metals and polymers. Alumina is most commonly used as a femoral head component instead of a metal in a hip prosthesis because this would reduce the polyethylene wear that is generated. Alumina is a desirable biomaterial to use in hard tissue implants because of characteristics like excellent wear resistance, high hardness, bio inert, low abrasion rate and good frictional behaviour. Furthermore, it has excellent surface finish as well as high fatigue streng...
Osteoporosis is a condition, which advances with age, resulting in fragile, weak bones due to a decrease in bone mass. Externally osteoporotic bone is shaped like normal bone, however it’s internal appearance differs. Internally the bone becomes porous due to a loss in essential minerals, including phosphate and calcium. The minerals are loss more quickly than they can be replaced and in turn cause the bones to become less dense and weak. The bones become prone to fracture, due to their weakness. Therefore the awareness of the disease tends to occur after a fracture has been sustained. The bones most commonly affected are the ribs, wrist, pelvis and the vertebrae.
Arthritis is a common thing in older individuals to acquire, especially in the hip and knee. These discoveries may lead to safer and more cost effective ways to replace bone after it has been compromised by things such as arthritis. Logically, it would be advantageous to create a structure with structure and properties similar to that of human bone to replace human bone. Recreating human bone is the next step in the timeline of artificial bone’s role in artificial bone replacement.
Lincoln Rhyme, former head of Central Investigation and Resource Division, is persuaded by Lon Selitto and his partner to help the kidnapping investigation. In the mean time, the "Bone Collector" abducts another victim.
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.
Osteoporosis, which means “porous bone, ” is a disease of weak and brittle bones.(nof 1) Osteoporosis makes bone mineral density loss. In a result, the possibility of fracture is increased because the bone is fragile. The size or volume of the bone is same, however, the mass of bone runs low on. This condition is the sympt...
Total Hip Replacement (THR) is a surgical procedure that relieves pain from most kinds of hip arthritis, thus helping to improve the quality of life for the majority of the patients that undergo the operation. Arthritis simply means "inflammation of a joint." Arthritis can occur in any joint in the body. The main symptom of arthritis is pain which usually worsens with activity and weight bearing. This pain may be relieved most of the time through rest. There are over 100 types of arthritis but less than a handful account for over than 95 percent of the hip replacements that are performed. Some of these include Osteoarthritis (causes deterioration of the cartilage and the growth of bone spurs), Rheumatoid arthritis and Osteonecrosis of the femoral head. Doctors suggest that before considering hip replacement surgery for arthritis that the patient tries a number of non-operative interventions. Your doctor may have you consider little things such as weight loss (most arthritis is caused due to the weight bearing on a joint), activity modification or even the use of a cane. Patients should consider THR when daily living activities become harder to accomplish due to the pain. These activities would include walking, climbing stairs or other moderate pastimes. Anti-inflammatory medications which will help reduce the inflammation from the arthritis and reduce your pain may also be prescribed by the patient's doctor.
The two controversial topics discussed below share a single goal: to enhance the quality of life of a human individual. The first topic, transhumanism, is a largely theoretical movement that involves the advancement of the human body through scientific augmentations of existing human systems. This includes a wide variety of applications, such as neuropharmacology to enhance the function of the human brain, biomechanical interfaces to allow the human muscles to vastly out-perform their unmodified colleagues, and numerous attempts to greatly extend, perhaps indefinitely, the human lifespan. While transhumanist discussion is predominantly a thinking exercise, it brings up many important ethical dilemmas that may face human society much sooner than the advancements transhumanism desires to bring into reality. The second topic, elective removal of healthy limbs at the request of the patient, carries much more immediate gravity. Sufferers of a mental condition known as Body Integrity Identity Disorder seek to put to rest the disturbing disconnect between their internal body image and their external body composition. This issue is often clouded by sensationalism and controversy in the media, and is therefore rarely discussed in a productive manner (Bridy). This lack of discussion halts progress and potentially limits citizens' rights, as legislation is enacted without sufficient research. The primary arguments against each topic are surprisingly similar; an expansion on both transhumanism and elective amputation follows, along with a discussion of the merit of those arguments. The reader will see how limits placed on both transhumanism and elective amputation cause more harm to whole of human society than good.
By definition, "osteoporosis, or porous bone, is a disease characterized by low bone mass and structural deterioration of bone tissue, leading to bone fragility and an increased risk of fractures of the hip, spine, and wrist" (National Institute of Health- Osteoporosis and Related Bone Diseases, 2012). Both Berarducci (2008) and Hansberger’s (2005) article note that osteoporosis is the most common disease of all bone disorders, affecting both men and women. The incidence of the disease is growing in the United States with almost 44 million affected Americans and an estimate incidence rate of 10 to 14 million by 2020. Deemed a "silent" epidemic, there is a low level of diagnosis, and even lower level of treatment. Walker (2010) supports Hansberger (2005) that the disease causes pain, depression, anxiety, loss of mobility, and ultimately fractures. It is crucial that Advanced Practice Nurses/Nurse Practitioners have a solid understanding of the disease and are able to identify risk factors, order the proper diagnostic testing, and treat their patients.
The human body endures a great deal of wear and injury during its lifetime. It is for this reason that the body has several tissues that are capable of regeneration. Bone is one of those tissues that receives extensive use so it is necessary that it is strong in order to carry out its functions; however, it will occasionally face injury. Although our bones are capable of regeneration, a new method would help the elderly and others that have a more difficult time healing after injury. I viewed a “TED Talk” lecture, which discussed a new way of regenerating bone with the help of our own bodies. Molly Stevens, the head of a biomaterials lab, presented “A New Way to Grow Bone” where she discussed a new technique called “in vivo bioreactor”. She also answered why this new procedure is beneficial. Researchers like Stevens are constantly trying to find innovative new techniques and they do this by asking questions. The question that Stevens presented in the video was an intriguing one: “Can we recreate the regeneration of bone on demand and transplant it?”.
Researchers from the University of Southampton propose that gels made from clay may administer the right environment that would stimulate stem cells to regenerate lost tissue such as cornea, bone, skin, heart, spinal cord, liver and pancreas. Clay particles attract molecules to bind together. Scientists propose that will be able to use the clays encouragement to get stem cells to grow new tissue. Researchers first approach is to regenerate bone lost to cancer or hip replacement failure. If researchers are successful, then stem cells can be brought to a whole other level. Stem cells could be applied to burn victims or to people suffering from diabetes or parkinson 's disease. Clay particles are what could be needed to stimulate the process at a particular point of injury. There are two major challenges for the purpose of basic stem based therapies. The first major challenge is being able to hold the stem cells at the right location. Researchers propose that clay particles gelled in water can injected into the body and held at the exact site of injury eliminating the need for surgery. Clay particles also interact with polymers which are used in scaffolds, which stem cells grow on. Researchers hope this will improve the scaffold’s strength to preserve the support at the site of injury until regeneration is done. The ability of clay to overcome these is huge(Life Science Weekly). Also
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