Today, orthopaedics is still in search for the most reliable biomaterial for prosthesis. The biomaterial needs to have good longevity and other supporting properties in order to maintain low implant failure. An ideal metallic biomaterial should be biocompatible, has similar elastic modulus to that of bone, has excellent resistance to fatigue, corrosion, aseptic loosening, and wear, and has good bone-bonding ability. The success of an implant depends on many factors. Good osseointegration is one of the factors required to reduce the rate of loosening of implants and in order to increase the chance of osseointegration, high stability of implants and early healing process encouragement are needed.

As a steroid hormone, cortisol has a close relationship with the stress response, and therefore, can be used as a biomarker for early detection of stress. An electrochemical immunosensor is one of the most widely used methods to detect cortisol, with antibodies as its bioreceptor. Apart from conventional laboratory-based methods, the trend for cortisol detection has seemed to be exploiting antibodies and aptamers. Both can provide satisfactory performance with high selectivity and sensitivity, but they still face issues with their short shelf life. Molecularly imprinted polymers (MIPs) have been widely used to detect macro- and micro-molecules by forming artificial antibodies as bioreceptors. MIPs are an alternative to natural antibodies, which despite demonstrating high selectivity and a low degree of cross-reactivity, often also show a high sensitivity to the environment, leading to their denaturation. MIPs can be prepared with convenient and relatively affordable fabrication processes. They also have high durability in ambient conditions, a long shelf life, and the ability to detect cortisol molecules at a concentration as low as 2 ag/mL. By collecting data from the past five years, this review summarizes the antibody and aptamer-based amperometric sensors as well as the latest developments exploiting MIPs rather than antibodies. Lastly, factors that can improve MIPs performance and are expected to be developed in the future are also explained.

This paper presents the realisation of conductive matrices for application to tissue engineering research. We used poly(L-lactide (PLLA)), poly(ε-caprolactone) (PCL), and poly(lactide-coglycolide) (PLGA) as polymer matrix, because they are biocompatible and biodegradable. The conductive property was integrated to them by adding single wall carbon nanotubes (SWNTs) into the polymer matrix. Several SWNTs concentrations were introduced aiming to understand how they influence and modulate mechanical properties, impedance features and electric percolation threshold of polymer matrix. It was observed that a concentration of 0.3% was able to transform insulating matrix into conductive one. Furthermore, a conductive model of the SWNT/polymer was developed by applying power law of percolation threshold.