Textile Scaffold Presentation

“Textile Scaffolds For Tissue Engineering”: 

“Textile Scaffolds For Tissue Engineering” A Seminar On

PowerPoint Presentation: 

Use of textile structures in a medical field is not recent because sutures, which for centuries have been used for closure of wound or incision, or fundamentally textile structures. Due to recent advancements in textile engineering and bio-medical research the use of textiles in surgery is growing. They are routinely used to supplement or replace the functions of living tissues of the human body. Soft tissue replacement or implants such as vascular graft, skin grafts, hernia patches and artificial ligaments are made of textile filaments Moreover polymers reinforced with textiles, called polymer composite materials, are also considered in hard tissue replacements, spine rods, intervertebral disks and spin cages. Introduction

Scaffolds??: 

Scaffolds??

Scaffolds for Tissue Engineering: 

Scaffolds for Tissue Engineering Cells are isolated from the patient’s body, and expanded in a petridish in laboratory. Once we have enough number of cells, they can be seeded on a polymeric scaffold material, and cultured in vitro in a bioreactor or incubator. When the construct is matured enough, then it can be implanted in the area of defect in patient’s body.

The scaffolds are three dimensional, porous structures encourage cell attachment, proliferation and migration through an interconnected network of pores. Scaffolds are artificial devices, designed to act as templates for attached cells and newly formed tissues. : 

The scaffolds are three dimensional, porous structures encourage cell attachment, proliferation and migration through an interconnected network of pores. Scaffolds are artificial devices, designed to act as templates for attached cells and newly formed tissues. Scaffolds

How do the Scaffold work?: 

How do the Scaffold work?

What are Scaffolds made of ??: 

What are Scaffolds made of ??

PowerPoint Presentation: 

Natural materials such as Collagen, Elastin, Keratin, Silk, Chitin ,Fibroin,Chitosan and Mussel Proteins. Synthetic materials The non degradable materials such as Polyethylene , PTFE etc. Synthetic bio degradable polymer such as Polyester, Poly anhydride , Poly Orthoesters, Polyphosphazenes, etc. Poly(L-lactic acid) (PLLA) / polyethylene glycol(PEG) mixed solutions were successfully electro spun into micro or nano fibrous polymer mates , Poly(lactic-glycolic acid) (PGLA) ,CNT(carbon nano tubes) etc.

Why is Nanofibrous Scaffolds preferred?: 

Why is Nanofibrous Scaffolds preferred?

Nanofibrous Vs Microfibrous Scaffolds : 

Nanofibrous Vs Microfibrous Scaffolds

Synthesis of Tissue Engineering Scaffolds: 

Synthesis of Tissue Engineering Scaffolds A number of different methods have been described for preparing porous structure to be employed as tissue engineering scaffolds. Nanofiber Self-Assembly Solvent Casting & Particulate Leaching (SCPL) Gas Foaming Emulsification/Freeze-drying Thermally Induced Phase Separation (TIPS) Electro spinning Currently, two methods, phase separation and electro spinning have been used to prepare the nanofiber with diameters ranging from 100 to 900 nm .

Thermally Induced Phase Separation (TIPS): 

Thermally Induced Phase Separation (TIPS) In phase separation ,procedure requires the use of a solvent with a low melting point that is easy to sublime. For example dioxane could be used to dissolve polylactic acid, then phase separation is induced through the addition of a small quantity of water. A polymer-rich and a polymer-poor phase are formed. Following cooling below the solvent melting point and some days of vacuum-drying to sublime the solvent, a porous scaffold is obtained.

Electro spinning: 

Electro spinning In a typical electro spinning set-up, a solution is fed through a spinneret and a high voltage is applied to the tip. The buildup of electrostatic repulsion within the charged solution, causes it to eject a thin fibrous stream. A mounted collector plate or rod with an opposite or grounded charge draws in the continuous fibers, which arrive to form a highly porous network. A typical electro spinning set-up only requires a high voltage power supply (up to 30 kV), a syringe, a flat tip needle and a conducting collector. Schematic of the electro spinning process

Scaffold Structural Design Parameters: 

Scaffold Structural Design Parameters For a scaffold to function effectively It must possess the optimum structural parameters, conducive to the cellular activities leading to new-tissue formation These include cell penetration and migration into the scaffold, cell attachment onto the scaffold substrate, cell spreading and proliferation and cell orientation.

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Porosity for cell migration Balance between surface hydrophilicity and hydrophobicity for cell attachment Mechanical properties comparable to natural tissue to withstand natural loading conditions Degradation capability so that it gets completely reabsorbed after implantation Nontoxic by products 3D matrix. Scaffolds should have the following characteristics:

PowerPoint Presentation: 

Scaffold Function Scaffold Design Parameter Non inflammatory or non toxicity in vivo Biocompatible, non-Toxic and non-carcinogenic. To assist in the growth of 3-d tissue & organs 3-d scaffold of specific shape. To promote cell proliferation and migration leading to tissue growth throughout the scaffold. Optimum pore size to allow for cell penetration, with high porosity & interconnectivity between pores. To allow for the movement of nutrients and waste in & out of the scaffold. High porosity and interconnectivity between pores. The scaffold may degrade to leave only natural tissue. Rate of degradation to match the rate of tissue formation. Support for developing tissue and withstand in vivo forces. Scaffold should have mechanical properties of developing tissue. Basic Functions of Scaffold

Applications of Scaffolds: 

Applications of Scaffolds A knitted Poly(lactic-glycolic acid) (PGLA) scaffold seeded with bone marrow stem cells. A micro braided tube was successfully used as a nerve guide growth conduit in regenerating a 10mm nerve gap with a 90% success rate. A multi layer-knitted PGLA and Polycaprolactone (PCL) co-fiber as also been used for skin tissue generation, Heart valve, Tendons and Ligaments. A woven polyethyleneterephthalate (PET) textile rolled into a cylinder was successfully used for dynamic hepatocyte cell culture. A composite tube made of braided PGLA coated with a porous PLA-PCL copolymer has been used for blood vessel regeneration, with its elasticity adjusted to mimic the native blood vessel. Application of electro spun poly( l -lactic) acid (PLLA) nanofibrous scaffold seeded with chondrocytes for cartilage tissue engineering.

PowerPoint Presentation: 

Application

Conclusion : 

Conclusion Scaffolds are a boon to Mankind Textile structure are particularly attractive to tissue engineering because of their ability to tailor a broad spectrum of scaffolds with a wide range of properties. Further systematic study is necessary to design a optimal scaffold for each tissue applications. Textile scaffolds are extreamly versatile and therefore ideal for encouraging cells to recreate tissue geometry. They are easily adapted to meet different cell requirements which will be an emerging trend in Medical Textiles.

Thank You : 

Thank You