[Porous structures via microbubbling :Literature review only]

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Table of Contents

CHAPTER 2: LITERATURE REVIEW1

Introduction to Porous Structures1

Porous Materials4

Properties Of Porous Permeable Materials4

The Coefficient Of Pore Tortuosity5

Pore ??sizes6

Formation of Porous Structures Nanosized Materials7

Biomedical Engineering7

Biomechanics8

Implants (Hip Replacement)8

Synthesis of Scaffolds Of Tissue Engineering9

Drug Delivery13

Electro spinning14

Pore Structures and Micro Bubbling Discussed16

REFERENCES24

CHAPTER 2: LITERATURE REVIEW

Introduction to Porous Structures

Polymeric fibers, particles, membranes and porous scaffolds have attracted great interest in the recent research of biomedical engineering. The practical applications of these structures of biopolymers vary from wound dressing, drug delivery, and vascular grafts to tissue engineering scaffolds. An example of a porous polymeric structure used in tissue engineering. A majority of these, although not all, involve the use of three-dimensional polymeric scaffolds implanted at a tissue defect site to both replace the function of the tissue temporarily and help the body to regenerate or repair it. The scaffolds must therefore provide a suitable substrate for cell attachment, proliferation, and differentiated functions and, in certain cases, cell migration. Such applications place strict requirements on the physical and chemical properties of the specific polymeric scaffolds. The porous structure must provide space for cell to grow in and facilitate the transport of cells and nutrients to maintain normal cellular activities. The loss in mechanical properties of the reabsorb able polymer should match the temporal development of the strength in the native tissue. The polymer scaffolds can also serve as carriers for cells, growth factors, and/or other bio-molecular signals in order to obtain targeted and controlled release of these active ingredients.

A manufacturing process of porous structures is to form a dry mixture comprising a component providing primary separation capability, a component that provides capacity strengthening of green strength and a component that provides binding capacity and is selected from the group consisting thermoplastic polymers and thermosets, distribute the mixture on a suitable surface to have a desired thickness of the same; densify the mixture into the desired shape of the porous structure; removing densified porous structure of the surface, bundle the component that provides the ability primary separation melting the mixture at a temperature up to about 20C or greater than the melting point of any thermoplastic component to provide binding capacity. Porous structures according to the present invention comprise between about 70 and 90 parts by weight of a component providing primary separation capability between approximately one and 15 parts per weight of a component that provides capacity strengthening of green strength, and between about 8 and 20 parts by weight of a component that provides binding capacity and is selected from the group consisting of ...