ALUMINA FIBERS IN ORTHOPEDICS IMPLANT:

Osteoblast Adhesion Application

Dr.Hasmaliza Mohamad Ruzainah Abdullah

School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang, Malaysia

Alumina (Al

2

O

3

)

Alumina

is an important engineering material for high temperature industries.

Properties :

 High strength and modulus.

 Resistance to attack by molten metals and non-oxide materials.

 Chemical inertness in both oxidizing and reducing atmosphere.

 Low thermal conductivity and good electrical insulation

Biomedical application of Al

2

O

3 • Dental Implant • Bone implant – Joint replacement: Knee prostheses, ankle – joint, shoulders and fingers.

– Implant adhesion: Osteoblast adhesion

Objectives

• To increase the activities of bone cells on the surface of material used in the design of orthopedic implants.

• Enhanced functions of osteoblasts

Previous study: •Frequently, problems with orthopaedic implants occur owing to either loosening of the implant, osseo-degradation of bone surrounding the implant or hypersensitivity of the patient to the particular metal •Hydroxyapatite-coated implants have been successful for the most part. It has been found that bone apposition on the surface of porous hydroxyapatite-coated implants is better than that on metallic porous coatings

Previous study: (cont..) • However, numerous problems are still encountered with these approaches. For example, the average lifetime of hydroxyapatite-coated implants needs improvement, owing to high solubility rates that can lead to degradation of the coating and loosening at the bone-hydroxyapatite interface

Present study: • Alumina fibers will use to increase the coating toughness • Electrospinning provides opportunities to manipulate and control surface area, fiber diameter, porosity and pore size of nanofiber matrices • Study the effect of various properties of alumina fibers on adhesion

Synthesis of the alumina fiber

sol – gel 

Electrospinning

 press  sinter The combination of sol-gel processing with electrospinning techniques will provides a versatile technique for producing ceramics nanofibers

EXPERIMENTAL PROCEDURE: Fibre

PREPARATION OF 0.5M AL.NITRATE

AQEOUS SOLUTION ADD SIMULTANOUSLY AL. ISOPROPOXIDE INTO 0.5M AL. NITRATE STIR VIGOROUSLY FOR 24 HRS AGE IN DRY OVEN ABOUT 50 C UNTIL GET CLEAR SOLUTION SLOW HEATING TO GET SPINNABLE SOL SPIN TO GET GEL FIBER CALCINATION FIBER ANALYSIS

SEM image of nanofibers

The aim of nanoscale alumina in osteoblast adhesion

• Nanofiber alumina (less than 100 nm in diameter) more closely simulates the physical geometry of hydroxyapatite crystals and collagen fibers in bone that osteoblasts are accustomed to interact to.

Advantages of alumina fibers in osteoblast adhesion:

• Increase the toughness of HAp coating • Give good adhesion to implant • Increase the degradation rate of HAp coating