Adverse effects after biomaterial implantation

 

Adverse effect is similar to side effect but is more severe and undesirable. Biomaterials can cause adverse effect when implanted because of the toxicity and degradation. Examples of the effect are such, inflammation, toxicity and allergy. This paragraph is about an example of the adverse effects by titanium dioxide nanoparticles (TiO₂) and the method to avoid such effect.[4] TiO₂ is a next gen biomaterial and is broadly used in sunscreen. TiO₂ is used because it is absorbs huge amount of UV radiation due to its large surface area to volume ratio. But TiO₂ induces oxidative damage by its cytotoxicity. Because the absorbing UV lights generates reaction oxygen species (ROS). Together with the large surface area due to TiO₂ being a nanoparticle, this further increases the amount of ROS which is the origin of TiO₂’s adverse effect. Because ROS causes genetic damage and damage to cell functions after TiO₂ penetrating through cell membranes. In an experiment of incubating rutile TiO₂ with human dermal fibroblast for 6 days, images [4] below show that the cell area decreases along with the distortion in the morphology of cells.

The important thing to note is that actin fibres have become thinner and shortened. Actin controls cell division and so the cell number has decreased as a result of the implantation of TiO₂. It is showed in the charts that the higher the concentration of TiO_2, the lower the number of cells in the testing well. Therefore, the cell function of human dermal fibroblast is affected. To avoid the adverse effects, TiO₂ is coated with a dense polymer to stop itself from adhering and therefore penetrating through the cell membranes. Also, the coating traps the photoelectrons which suppresses the ROS production, meaning the actin fibres would not be affected in any form.