Photocrosslinkable starch-based polymers for ophthalmologic drug delivery

Abstract

a b s t r a c tThis study focused on the development and characterization of a starch-based polymer with urethane linkages to be used as a controlled drug delivery system for biomedical applications. Starch was modified with 2-isocyanatoethyl methacrylate in order to obtain a polymer containing carbon-carbon double bonds in its structure. This modified starch was then used to produce films by UV irradiation using Irgacure ® 2959 (CIBA) as the photoinitiator. The modified polymer was characterized by attenuated total reflectanceFourier transform infrared (ATR-FTIR) spectroscopy. The swelling capacity, in artificial lachrymal fluid (performed both at room temperature and physiological temperature), and water contact angles measurements were determined. The in vitro biodegradation in artificial lachrymal fluid supplemented with lysozyme was also studied. Scanning electronic microscopy (SEM) was used to characterize the morphology of the materials immediately after synthesis and after biodegradation. Timolol maleate and sodium flurbiprofen were immobilized by adsorption and their in vitro release profiles were followed spectroscopically.

pH-sensitive sodium alginate/poly(vinyl alcohol) hydrogel beads prepared by combined Ca2+ crosslinking and freeze-thawing cycles for controlled release of diclofenac sodium

“…Utilization of natural polymers for the design of drug delivery system has long been the subject of great interest during the past decades [1][2][3]. Sodium alginate (SA) is a polyanionic linear copolymer of 1,4-linked-␣-l-guluronic acid and ␤-d-mannuronic acid residues found in brown seaweeds.…”

Photo-irradiation paradigm: Mapping a remarkable facile technique used for advanced drug, gene and cell delivery

“…Often the formulation occurs by simple mixing of drug(s) with PRP before nanoassemblage and photo-irradiation process [11], however, some researchers load the candidate drug(s) after preparing the particles and before integrating them through photo-irradiation. For example, the photoirradiated hyaluronic acid nanoparticles loaded with paclitaxel that was reported by Yoon et al [158].…”

Photocrosslinkable Polymers for Biomedical Applications

“…These modifications allow us to improve some of their assets such as hemo and biocompatibility. It is also possible, by using radiation, to prepare crosslinked systems that may be used to encapsulate cells (Cruise et al, 1999;Hill et al, 1997;Li et al, 2006), proteins (Leach et al, 2005) or other compounds to be controlled delivered (Vieira et al, 2008;Tripodo et al, 2005). In the following sections a literature review in some of the possible applications of photocrosslikable polymers will be presented.…”

“…In order of overcoming this limitation biodegradable systems have been prepared based on several different polymers, namely: poly(lactic-co-glycolic acid) (Yasukawa et al, 2005); polycaprolactone (Shi et al, 2005); polyanhydrides (Leong et al, 1986) and poly(ortho esters) (Heller, 2005). In our research group, a starch-based polymer with urethane linkages to be used as a controlled drug delivery system for biomedical applications was developed (Vieira et al, 2008). Hydroxyl groups present on starch were modified with 2-isocyanatoethyl methacrylate (IEMA) in order to obtain a polymer containing carbon-carbon double bonds.…”