Fingernails and toenails are made of a tough protein called keratin and have many different parts. Nails can dry out, just like skin. They can also peel, break and be infected. Toe infections, for instance, can be caused or exacerbated by dirty socks, specific types of aggressive exercise, tight footwear, and walking unprotected in an unclean environment. Artificial nails, also known as fake nails, fashion nails, nail enhancements, or nail extensions, are coverings placed over fingernails as fashion accessories. Some artificial nails attempt to mimic the look of real fingernails as closely as possible, while other designs may deliberately stray in look from real fingernails. Artificial nails are made from a wide variety of materials.
The purpose of this dissertation is to analyze the effect of polyglutamic acid (PGA) on the recovery of defect of injured nails caused by artificial nail treatments. PGA is a polymer of the amino acid glutamic acid (GA). Gamma PGA (the form where the peptide bonds are between the amino group of GA and the carboxyl group at the end of the GA side chain) is a major constituent of the Japanese food natto. Gamma PGA is formed by bacterial fermentation. The scope of this dissertation included the electron microscopy analysis of nail plates and cross-sections before and after the treatments. In this study, I have shown that an artificial nail treatment produces very harmful effects although it was just once. PGA of three different molecular weights showed the positive effect on nail condition all together. Especially PGA with molecular weight of 5,000 Da (BLS 5) represents the best recovery effect. On the other hand, the control untreated group did not show the recovery appearance. For the term of use of PGA, 4 weeks was better than 2 weeks. The initial recovery rate (2 wk) is much faster than the latter one (4 wk). PGA effects were noticeable more on nail section than on nail plate according the SEM data. As a summary, PGA could be used as an ingredient in nail guard and mush work should be done before preparing the commercial product.