Design a bioreactor that can replicate the in vivo loading conditions Essay

Design a bioreactor that can replicate the in vivo loading conditions experienced by bone cells in the body - Essay Example It is followed by the dedifferentiation of the cells. This process produces only a minimal concentration of the cells. Hence the use of micro carrier cultures is done for the well-mixed bioreactor systems. The defects in the skeleton system are a big impediment to the normal functioning of the human system. The autogenous bone transplantation is practiced for the bone replacement so far. (Schieker, 2006).This method has increased risk of surgery and post operative morbidality to the patients. This method also has the disadvantage of limited quantity and the secondary operational procedure costs. The calcium phosphate ceramics is widely used for the production of the bone supplement. The hydroxyapatites of the calcium phosphate ceramics have considerable clinical use because of their chemical and relvant crystallographic structures to bone. The cell based therapy aims at developing the 3D biohybrid structure of a scaffold and cultured cells. The bioreactors that are established for th e microbes and mammalian cultures are not suitable for the 3D structure constructs. Hence the need for a tissue specific bioreactor design arose. To restore back the skeleton function, the bone tissue engineering is used. The production of tissue engineered piece of spongy bone is one of the challenging fields in bone tissue engineering. The three key elements of bone tissue engineering are osteogenic progenitor cells, osteoinductive growth factors and osteoconductive matrices. Osteoblasts are the differentiated cells that arise from the osteoprogenitor cells. These cells are very mobile and they change the shape and size according to the matrix of the bone. These cells appear with in the vascular tissue. These cells are responsible for the synthesis and the secretion of the organic matrix of the bone. Bone remodeling and the bone reformation are the two types of the tissue engineering processes that can are possible with the osteoblast cells.

Effects Of Organic Waste Pollution On The Natural Environment Essay

Effects Of Organic Waste Pollution On The Natural Environment - Essay Example Water cycle that consist of material flow on earth’s surface to water masses are some of the causes of water pollution as the flows collect materials into water bodies and are vulnerable to intentional pollution through domestic and industrial waste disposal. This paper discusses environmental effects of organic waste pollution and reviews an article that uses toxicology to investigate the impacts of water pollution on the natural environment. Effects of organic waste pollution on the natural environment Organic discharge into water bodies has varying effects on the environment. One of the effects of organic pollution is the disintegration of organic matter to changed odour and taste of water. Effects of continuous degradation are accumulation of compounds such as hydrogen sulphide and mercaptans and this leads to gradual increase in changed odour and taste of water that may not be suitable for sensitive flora and fauna. Organic pollutants also destabilize oxygen concentration in water masses. Many factors lead to this shift from equilibrium of water concentration. Processes of organic components of water such as photosynthesis and respiration uses oxygen and may change oxygen concentration in water. Photosynthesis may increase concentration beyond its equilibrium while respiration may reduce the level of concentration. Anaerobic respiration and oxidation of organic pollutants are other factors that can reduce oxygen concentration in water. ... Insufficient oxygen in water may also cause death of aquatic animals. Such deaths further leads to accumulation of organic compounds in water and worsen the problem with oxygen concentration. Death of plants and animals in the water bodies also generate aesthetic effect besides increasing water turbidity (Goel 2006, p 116- 120). Organic pollution also affects levels of production of aquatic plants and animals. As the pollutants begin to invade water bodies, aquatic plants and animals benefits from nutrients that the organic pollutants may contain and this leads to high rates of photosynthesis and respiration among other processes. Increased concentration of organic pollutants however have adverse effects on aquatic lives as respiration rates increase and this leads to aesthetic effect and instability in oxygen concentration. Accumulation of organic pollutants also increases concentration of chemical compounds such as hydrogen sulphide and ammonia, chemicals that have adverse effects on some plant and animal species such as phytoplankton. High levels of organic pollution are also a threat to biodiversity. At normal water conditions, without organic pollutants, all aquatic plants, and animals are able to survive and their populations are constant. High levels of pollution however threaten the lives and less tolerant plants and animals die. Some plants and animals may however be tolerant and survive the harsh conditions due to the pollution. Consequently, aquatic life will consist of the tolerant species that may only be few. Loss of biodiversity from the pollution can also be permanent, unless artificial measures such as reintroduction of the extinct species upon resumption of normal condition in the polluted aquatic environment. Organic