Pegylated bis-indolyl polyurethane dendrimer : Empty drug carrier with prominent anticancer activity

Blocked isocyanate-terminated, bioactive bis-indole based polyurethane dendrimers of generation G0 – G3 were subjected to urethane interchange reaction with poly(ethylene glycol) monomethyl ether; the reactions yielded corresponding PEGylated dendrimers. The structures of the PEGylated dendrimers were confirmed using spectroscopic and SEC-MALS techniques. The PDI of the polymers were found between 1.24 and 1.49 and these values were on par with 1.46 of poly(ethylene glycol) monomethyl ether used. All the PEGylated dendrimers were found to have a prominent cytotoxicity in human breast (MDA MB-231) and lung (A549) cancer cells. Based on the MTT, AO/EtBr staining and ROS assay results, PEGylated G2 and G3 dendrimers were further subjected to determination of apoptosis using protein markers; the pro-apoptotic markers BaX and caspase-3 were found up regulated and the anti-apoptotic marker Bcl-2 was down regulated. The results confirmed that the PEGylated bis-indolyl G3 polyurethane dendrimer – an empty drug carrier – itself had strong tendency to activate apoptosis type cell death in human cancer cells

Development of a novel smart carrier for drug delivery: Ciprofloxacin loaded vaterite/reduced graphene oxide/PCL composite coating on TiO2 nanotube coated titanium

In the field of orthopaedic implants, post-surgery infections and biocompatibility are the most challenging ob-stacles. Sustained and controlled antibiotic release is a key factor in novel drug delivery systems. A novel drug delivery system combined with vaterite microsphere, graphite oxide (GO), reduced graphene oxide (rGO) incorporated in a polycaprolactone (PCL) matrix on TiO2 nanotube coated Ti (TNT-Ti) is established. Anodiza-tion was employed to develop TiO2 nanotubular arrays on Ti. Ciprofloxacin hydrochloride (CPF-HCl) loaded vaterite microspheres were synthesized by in situ precipitation method. Deposition of vaterite/PCL, vaterite-GO/ PCL and vaterite-rGO/PCL composite coating on TNT-Ti was carried out by dip coating method. The composite coatings were characterized for their phase content, morphological features and functional groups. Among the three types of composite coatings, vaterite-rGO/PCL composite coating is found to be capable of encapsulating CPF-HCl to a level of 75.14 mu g. The drug release profile of CPF-HCl from the vaterite-rGO/PCL composite coating exhibits a controlled release amounting to only 35.02 % of release at the end of 120 h. The vaterite-rGO/PCL composite coating exhibits a low dissolution rate and possesses adequate bioactivity in HBSS and SBF solu-tions at 37?degrees C for 14 and 10 days, respectively. The in situ loaded CPF-HCL drug on vaterite microspheres, PCL polymer matrix and GO/rGO nanofillers does not affect the cytocompatibility and all the composite coatings supported cell viability and proliferation. The ability of vaterite-rGO/PCL composite coating to provide a slow and steady release of antibiotics with sufficient bioactivity and biocompatibility at the tissue implant interface makes it a promising for osteomyelitis infection of bone tissue implant materials