Nanotechnology, especially nanofibers, has become attracted interest for tissue engineering application [1]. The large surface area to volume ratio is the unique properties of nanofibers, which consents cellular migration and proliferation in tissue engineering scaffolds [2]. The scaffold can be fabricated by several methods including solvent casting, particle leaching, phase separation, emulsion freeze drying, 3D-printing technique and many others [3]. However, the simplicity of electrospinning provides an advantage for nanofibrous scaffold construction [4]. Electrospinning is the most efficient method to fabricate continuous nanofibers from both synthetic and natural polymers. This method can produce polymer fibers with diameters ranging from micrometer down to nanometers [5]. Due to the most of extracellular matrix (ECM) of natural tissues is composed of a cross-linked network of collagen fibrils with diameter in the range from 15 µm down to 5 nm, which human cell deposit in and organize around these fibrils [6]. Thus, electrospinning technique has been interest for artificial m...
At the moment, the main objective for scientists and engineers is to develop surgery into a minimal invasive method and nanote...
Fiber is a threadlike material that can be found in a natural or manmade form. Natural fibers derive from various animals, plants and can even be produced by insects. These fibers have been in use since prehistoric times and are currently produced today. The most common natural fibers used are linen, wool, silk and cotton. They have been woven together to create fabrics for clothing and other items. A natural protein fiber, called wool, was discovered before 10,000 B.C.E. and woven into cloth by 1900 B.C.E. Wool comes from predominantly sheep but is also found in other animals such as, llamas, alpacas, camels and goats. Tribes in North Europe spun wool using a crude spindle, which is a stick with a stone or clay ring connected to the end to make yarn. They also made wool into cloth by weaving the thread in a criss cross style. Some humans 8,000 years ago had domesticated sheep specifically for the production of wool and other uses. In 4,000 B.C.E. the city of Babylon also known as the “Land of Wool”, had bought and sold woolen cloth which was important to their society. Over the years spinning and weaving machines were constantly improved like the spinning jenny built in 1767 with many spindles placed side to side allowing it to operate 120 spindles at once. Weaving wool became more machinery based rather than using the traditional manual weaving (“History of Wool”, n.d.). In order to create the fiber wool, there is a process of cutting the hair from the animal which is usually done manually by shearing specialist. After cutting, the sheared wool is cleaned and brushed to straighten out the fiber strands by hand. The wool is then placed into a carding machine where it goes through many bristled rollers and roved. The carding process separates the wool into small pieces and cooled in spools at the end of the machine. Soon the wool is spun into yarn and woven into cloth. Before this machinery process, many women known as spinsters took on the task of turn wool into cloth manually. Wool is commonly used to create sweater garments and coats for cool weather (“History of Fibers”, n.d.). The Fiber repels water well and fabric feels dry in damp or wet weather. A downside to wearing wool is that it attracts moths and carpet beetles that feed on the fabric.
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.
A group of polymer chains can be organised together in a fiber. How the polymer chains are put together is important, as it improves the properties of the material. The flexibility, strength and stiffness of Kevlar fiber, is dependent on the orientation of the polymer chains. Kevlar fiber is an arrangement of molecules, orientated parallel to each other. This orderly, untangled arrangement of molecules is described as a “Crystalline Structure”. A manufacturing process known as ‘Spinning’ is needed to achieve this Crystallinity structure. Spinning is a process that involves forcing the liquefied polymer solution through a ‘die’ (small holes).
Bone tissue engineering (BTE) plays an important role in treating bone diseases related to osteoporosis and other orthopedic treatments. Although several methods are used in orthopedic surgery, some bone transport methods such as autografting and allografting have a certain number of disadvantages. Both are expensive methods and they can be exposed to infections and diseases. Therefore, in stead of using these potential risky methods, bone tissue engineering process are used to treat in orthopedic treatments. In general, both tissue engineering and bone tissue engineering have major constituents including stem cells, scaffold, bioreactors and growth factors.
The granulation tissue formation stage of wound repair relies heavily on neovascularization, expanding the limits of O2 and nutrients diffusion in tissues through new blood vessel development. Vasculogenesis is the mechanism of new vessel formation by vascular progenitor cells instinctively self-assembling. However, the main focus of this article is angiogenesis, the augmentation of pre-existing blood vessels to yield new vessels. Angiogenesis is controlled by soluble factors released from the wound site such as vascular endothelial growth factor (VEGF) which activates human microvascular endothelial (HMVE) cells to begin sprouting and extending, forming the lumen within mature capillaries, and undergoing functional anastomosis. However, microenvrionmental signals also factor into the multistep process through the mechanical forces transmitted by extracellcular matrix (ECM) as physical interactions between cells and ECM modify cell shape and cytoskeletal structure. Furthermore, altering ECM elasticity, adhesivity, or topography, applying mechanical stress, or changing cell-generated traction force may also bring changes to capillary cell shape and function. Though regional variations of ECM mechanics and cell shape seem to mediate three-dimensional tissue pattern formations from neighboring cell growth and differentiation, the underlying mechanism that control gene transcription for angiogenic control through mechanical signals conveyed by ECM that assemble with growth factors still remain unknown.
Gels with low gelatin concentrations were fragile and had low mechanical strength. Concentration of gelatin was optimized to be 5% which satisfied the properties of an ideal scaffold for skin tissue engineering. Gelation does not occur in the absence of chemical cross-linker i.e. glutaraldehyde which indirectly indicates the absence of physical cross-linking in gelatin. The mechanical strength of the cryogels increased with increase in gelatin concentrations. It was observed that as the total concentration of polymer precursors was increased from 4% to 8%, glutaraldehyde requirement for synthesizing optimum cryogel decreased from 1.0% to 0.1% (Table 1.1). This result can be better explained by understanding the well studied aspect of cryogelation that in moderately-frozen solutions, dissolved substances concentrate in the regions of non-frozen solvent (un...
Over the last few years, there have been great advancements in the construction of self-healing skin. It is hoped in the future that it will be used for prosthetic limbs, skin on robots and potentially as phone screens that heal the cracks. However at the time, there are many complications and further developments necessary before the synthetic skin be used.
The term microgels are consists of two words and both these words have totally different meanings. The micro word is associated with the gel particle size. The word gel of microgel describes the swallon power of particles in suitable organic solvent [1]. So microgels contain very large molecular weight polymeric organization. Every particle of gel was existing as a particular polymer fragment. It is also define as colloidal scattering of gel molecules. The particle size of microgels should be lie from 10-1000nm [2]. The microgels plays an important role in the area of drug delivery[3]. The microgels also gains popularity in the field of nanotechnology and it enhanced day by day[4]. The greater change in their size is observed by varying the ionic strength or by applying the electric and magnetic field, by temperature and pH[5]. The particles of microgels are rounded and contains a water swallon polymeric organization [6].The amount of water for microgels are in the range from 10 to 90% which rely on the microgel diffusion chemistry. The
Yadav, P. R., & Tyagi, R. (2008). Biotechnology of animal tissues. New Delhi, IN: Discovery Publishing House.
The use of nanobots makes diagnostic procedures fast and more precise. This also leads to patient experience less invasive and more comfortable procedures. Nurses can implement effective interventions and the give better patient care.
...roduce stable electrically conductive bio-nano-composite tissue materials that have been used as temperature sensing elements. This is an exciting new area of scientific discovery. I am eager to read more about the benefits and possibilities that exist with this new biotech process.
In 1950s and 1960s first generation biomaterials were introduced that could be used inside the human body. There are certain requirements that were meant to be posses by a first generation biomaterials including biocompatibility and biofunctionality. These matrials don’t induce mutagenic effects as well. Dialysis tube that is made by cellulose acetate is an example of first generation biomaterials.
Polymers popularly coined as “plastics” have proved their importance in different areas like FMCG, pharma, automobiles, etc. Plastics are versatile materials with unique properties like high strength to weight ratio, good aesthetics; good Processability, balanced engineering properties and optimum cost led its entry into medical
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]