title: Graphene-based electroresponsive scaffolds as polymeric implants for on-demand drug delivery.
abstract: Stimuli-responsive biomaterials have attracted significant attention in the field of polymeric implants designed as active scaffolds for on-demand drug delivery. Conventional porous scaffolds suffer from drawbacks such as molecular diffusion and material degradation, allowing in most cases only a zero-order drug release profile. The possibility of using external stimulation to trigger drug release is particularly enticing. In this paper, the fabrication of previously unreported graphene hydrogel hybrid electro-active scaffolds capable of controlled small molecule release is presented. Pristine ball-milled graphene sheets are incorporated into a three dimensional macroporous hydrogel matrix to obtain hybrid gels with enhanced mechanical, electrical, and thermal properties. These electroactive scaffolds demonstrate controlled drug release in a pulsatile fashion upon the ON/OFF application of low electrical voltages, at low graphene concentrations (0.2 mg mL(-1) ) and by maintaining their structural integrity. Moreover, the in vivo performance of these electroactive scaffolds to release drug molecules without any "resistive heating" is demonstrated. In this study, an illustration of how the heat dissipating properties of graphene can provide significant and previously unreported advantages in the design of electroresponsive hydrogels, able to maintain optimal functionality by overcoming adverse effects due to unwanted heating, is offered.
authors.affiliation: Nanomedicine Lab, Faculty of Life Sciences, University College London, London, WC1N 1AX, UK; Faculty of Medical & Human Sciences and National Graphene Institute, University of Manchester, M19 9PT, UK.
authors.forename: Ania
authors.initials: A
authors.lastname: Servant
authors.forename: Veronica
authors.initials: V
authors.lastname: Leon
authors.forename: Dhifaf
authors.initials: D
authors.lastname: Jasim
authors.forename: Laura
authors.initials: L
authors.lastname: Methven
authors.forename: Patricia
authors.initials: P
authors.lastname: Limousin
authors.forename: Ester Vazquez
authors.initials: EV
authors.lastname: Fernandez-Pacheco
authors.forename: Maurizio
authors.initials: M
authors.lastname: Prato
authors.forename: Kostas
authors.initials: K
authors.lastname: Kostarelos
mesh_terms: D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000737:chemistry / Q000633:toxicity; D004317:Doxorubicin / Q000737:chemistry / Q000633:toxicity; D004337:Drug Carriers / Q000737:chemistry*; D004560:Electricity; D006108:Graphite / Q000737:chemistry*; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D051379:Mice; D037742:Nanotubes, Carbon / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D011109:Polymethacrylic Acids / Q000737:chemistry; D012867:Skin / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D013395:Sucrose / Q000737:chemistry / Q000378:metabolism; D013814:Thermal Conductivity
chemical_list: D000903:Antibiotics, Antineoplastic; D004337:Drug Carriers; D037742:Nanotubes, Carbon; D011108:Polymers; D011109:Polymethacrylic Acids; C030613:polymethacrylic acid; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D013395:Sucrose; D006108:Graphite; D004317:Doxorubicin
keywords: electrical activation; graphene; implants; nanocarbons; nanomaterials; nanomedicine; polymers