Ceramics are known for their good biocompatibility, corrosion resistance, and high compression resistance. Drawbacks of ceramics include, brittleness, low fracture strength, difficult to fabricate, low mechanical reliability, lack of resilience, and high density. Polymer composite materials provide alternative choice to overcome many shortcomings of homogenous materials mentioned above. A lot of polymers are used in various biomedical applications; such as polyethylene (PE), polyurethane (PU), polytetrafluoroethylene (PTFE), polyacetal (PA), polymethylmethacrylate (PMMA), polyethylene terepthalate (PET), silicone rubber (SR), polysulfone (PS), poly(lactic acid) (PLA), and poly(glycolic acid) (PGA). Each type of material has its own posi­tive aspects that are particularly suitable for specific application. One of these appli­cations is an orthopedic implant. One of the major problems in orthopedic surgery is the mismatch of stiffness between the bone and metallic or ceramic implants. In the load sharing between the bone and implant, the amount of stress carried by each of them is directly related to their stiffness. In this respect, the use of low-modulus ma­terials such as polymers appears interesting; however, low strength associated with low modulus usually impairs their potential use. Since the fiber reinforced polymers, that is, polymer composite materials exhibit simultaneously low elastic modulus and high strength, they are proposed for several orthopedic applications 39. The mechani­cal properties of various polymers are shown in Table 2.5.39

When the diameters of polymer fiber materials are decreased from micrometers to submicrons or nanometers, there appear several amazing characteristics such as very large surface area to volume ratio, flexibility in surface functionalities and superior mechanical properties (stiffness and tensile strength) compared with any other known form of the material. A number of processing techniques such as draw­ing 40, template synthesis 41, phase separation 42, self-assembly 43, electrospinning 44, etc. have been used to prepare polymer nanofibers in recent years.

Cellulose, (C6H10O5)n, is the major component in the rigid cell walls in plants, a linear polysaccharide polymer with many glucose monosaccharide units. As an ac­etate ester of cellulose, cellulose acetate (CA) is a biodegradable polymer. CA scaf­folds have been used for growing “structurally mature” and “functionally compe­tent” cardiac cell networks 45. For ceramic-polymer hybrid systems, poor dispersion of ceramic powders in the polymer matrix and agglomeration of ceramic component has been a grave issue to the manufacturing of artificial scaffolds.

The use of nanotechnology has helped overcome these limitations. The synthe­sis of hybrid ceramic polymer nanofibers by means of electrospinning is a major breakthrough in biotechnology-related nanomanufacturing. Nanosized HAp pre­pared from eggshells and CA were combined to form novel hybrid 3D scaffolds mimicking the extracellular matrix (ECM) architecture.