Nanojel içeren pH'a duyarlı kompozit hidrojel sisteminin kontrollü ılaç salımı için kullanımı

In this study, both ultraviolet (UV) and visible-light have been used for the synthesis of novel hybrid pH responsive systems composed of poly(methacrylic acid-grafted-ethylene glycol), P(MAA-g-EG), and acryloyl group modified-cholesterol-bearing pullulan (CHPOA) nanogels. The system developed here has been utilized for controlled delivery of an anticonvulsant model drug pregabalin (PGB). The hydrophilic P(MAA-g-EG) network allows for pH dependent release of a loaded therapeutic agent, where CHPOA nanogel allows for the loading of a protein or hydrophobic drug into its structure. The hybrid hydrogels were synthesized under both UV and visible light, where bulk and surface initiated photopolymerization approaches were used. Bulk polymerized hydrogels were obtained through suspension of photoinitiator within the prepolymer solution, where uniform permeability properties were achieved for the synthesized pH responsive gel network. Surface initiated photo-polymerization was based on adsorption of photoinitiator onto an underlying substrate, where pH responsive hybrid gels with crosslink density gradients were obtained. Covalently attached nanogel within P(MAA-g-EG) hydrogel was characterized by Field Emission- Scanning Electron Microscope (FE-SEM). Swelling and release studies were carried out at pH 2.2 and 7.4 to mimic the physiological conditions in stomach and small intestine. Dynamic and reversible swelling experiments demonstrated higher swelling ratio profiles for visible light cured composite hydrogels. In addition, hybrid hydrogels incorporated with 5% nanogel, or synthesized with bulk photopolymerization demonstrated higher swelling. PGB release profiles at neutral pH demonstrated similarities for altered nanogel concentrations within the composite network. Biocompatibility of the hybrid network was also characterized using HeLa cell line in vitro. This approach for multifunctional membranes could be utilized for incorporation of specific molecules such as drug or protein with specific functionalities, so that sequential molecule delivery in response to specific stimuli could be achieved.