ABSTRACT
Kojic acid (KA), a fungal secondary metabolite, is commonly used in the cosmetic industry as a skin-whitening agent because of its ability to inhibit tyrosinase, the enzyme involved in melanin production. However, KA has shown poor depigmenting effects and becomes unstable after prolonged storage. Its use in cosmetics products has also been restricted due to its hydrophilic nature. To overcome these limitations, the structure of KA can be altered to form KA derivatives, such as KA ester (KAE), with improved chemical and biological properties. For instance, multiple studies have shown that KAE is more effective at inhibiting tyrosinase, is less toxic and more stable than KA, thus making it more beneficial. Aside from structural modification, nanotechnology applications such as nanoemulsion, and others have shown the ability to strengthen the efficacy of both KA and KAE by increasing skin permeability and delivering the drug more precisely to the targeted site with better controlled release rate. Therefore, the aim of this review article is to discuss the importance of modifying KA's chemical structure as well as the role of nanoemulsion, solid lipid nanoparticles (SLN), nanostructured lipid carrier (NLC), liposomes and ethosomes in improving topical delivery of KA and KAE for cosmetic and pharmaceutical applications.
ABSTRACT
Over the last decades, the strategy of using stem cells has gained a lot of attention in treating many diseases. Recently, DR was identified as one of the common complications experienced by diabetic patients around the world. The current treatment strategy needs to be addressed since the active progression of DR may lead to permanent blindness. Interestingly, varieties of stem cells have emerged to optimize the therapeutic effects. It is also known that stem cells possess multilineage properties and are capable of differentiating, expanding in vitro and undergoing genetic modification. Moreover, modified stem cells have shown to be an ideal resource to prevent the degenerative disease and exhibit promising effects in conferring the migratory, anti-apoptotic, anti-inflammatory and provide better homing for cells into the damaged tissue or organ as well promoting healing properties. Therefore, the understanding of the functional properties of the stem cells may provide the comprehensive guidance to understand the manipulation of stem cells making them useful for long-term therapeutic applications. Hence in this review the potential use and current challenges of genetically modified stem cells to treat DR will be discussed along with its future perspectives.
