RESUMO
Retinitis pigmentosa, or RP, is a group of inherited retinal degenerations involving progressive loss of photoreceptor cells- rods and cones- ultimately causing severe vision loss and blindness. RP, although a very common ailment, continues to be an incurable disease with little to be done medically. However, with the breakthroughs in gene therapy and stem cell transplantation in recent years, a new door has been opened to the treatment of RP. This narrative review summarizes the pathomolecular mechanisms of RP, focusing on the genetic and molecular abnormalities that lead to the process of retinal degeneration. In this section, we talk about the current theories of how RP develops, gene mutations, oxidative stress, and inflammation. We also delve into new therapeutic approaches such as gene therapy, stem cell transplantation and genome surgery, which are designed to either replace or repair the damaged photoreceptors to restore vision and ultimately enhance the life of the RP patient. Another topic covered is the obstacles and research frontiers of these revolutionary treatments. This article is intended to give a complete overview of the molecular processes of RP and the promising treatment strategies that could change the way this devastating disease is treated.
RESUMO
This article presents an analysis of the influence of heat treatment on chitosan nanocomposite film. A series of samples comprising: pure chitosan film, chitosan film embedded with nanocrystalline cellulose (NCC), chitosan film crosslinked with tannic acid and chitosan film with a blend of NCC and tannic acid were heat treated using a convection oven. Fourier-transform-infrared spectroscopy (FTIR) and X-ray diffraction test (XRD) shows the changes in chemical interaction of the heat treated films. The heat treated films show significant improvements in moisture absorption. Tensile strength and Young's Modulus were increased up to 7MPa and 259MPa, respectively when the samples were subjected to heat treatment. For the NCC particles, a transmission electron microscope (TEM) was used to inspect the structural properties of cellulose particle in suspension form.