Cell encapsulation unit) and N-acetyl-D-glucosamine (acetylated unit). It is derived from the N-deacetylation of chitin and has been used for several applications such as drug delivery, space-filling implants and in wound dressings. However, one drawback of this polymer is its weak mechanical properties and is thus often combined with other polymers such collagen to form a polymer with stronger mechanical properties for cell encapsulation applications. Agarose is a polysaccharide derived from seaweed used for nanoencapsulation of cells and the cell/agarose suspension can be modified to form microbeads by reducing the temperature during preparation. However, one drawback with the microbeads so obtained is
Insect Their muscles are able to contract multiple times for each single nerve impulse, allowing the wings to beat faster than would ordinarily be possible. Having their muscles attached to their exoskeletons is more efficient and allows more muscle connections; crustaceans also use the same method, though all spiders use hydraulic pressure to extend their legs, a system inherited from their pre-arthropod ancestors. Unlike insects, though, most aquatic crustaceans are biomineralized with calcium carbonate extracted from the water. The nervous system of an insect can be divided into a brain and a ventral nerve cord. The head capsule is made up