An examination of the thermorheological and drug release properties of zinc tetraphenylporphyrin-containing thermoresponsive hydrogels, designed as light activated antimicrobial implants

This study describes the thermorheological, mechanical and drug release properties of novel, light-activated antimicrobial implants. Hydrogels, based on N-isopropylacrylamide (NIPAA) and hydroxyethyl methacryl ate (HEMA) and either devoid of or containing zinc tetraphenylporphyrin, were prepared by free radical polymerisation and characterised using oscillatory rheometry and texture profile analysis. Drug release was studied at both 20 and 37 degrees C. Hydrogels containing NIPAA exhibited a sol-gel temperature (Tin), which increased as the proportion of HEMA increased and was

A review on the use of corneal implants for the treatment of presbyopia

In recent years there has seen an increased interest in refractive surgery for the correction of presbyopia. This can be attributed to a number of factors such as the increased demand from patients to have perfect vision without the need for glasses, spurred on by the success of high street refractive laser surgery. Also the World Health Organisation (WHO) estimated in 2005 that over a 1.04 billion people worldwide are affected by presbyopia (Holden et al. 2008). This vast number of people is valued as a potential market and is a huge enticement to the ophthalmic industry to try and develop devices and products to treat this condition. Recent advances in technology have renewed interest in the implantation of corneal inlays for surgical treatment of presbyopia. Dexl et al. (2011) suggest that the reason for this is the further development of biomaterial technology, advances in femtosecond laser and the need for a reversible presbyopic treatment.