title: A conductive nanostructured polymer electrodeposited on titanium as a controllable, local drug delivery platform.
abstract: Infection and inflammation associated with orthopedic implants can be life threatening, time consuming, and expensive, thus, motivating the development of a local drug delivery platform that could prevent such deleterious events. For this purpose, nanostructured polypyrrole (PPy) incorporating antibiotics and anti-inflammatory drugs (penicillin/streptomycin (P/S) or dexamethasone (Dex), respectively) were coated on commercially pure titanium through an easy to use electrochemical deposition method. As shown in our previous study, about 80% (compared with initial amount) of these incorporated drugs were released after electrical stimulation spanning five cycles (voltage was varied between -1 V and 1 V). In a further continuation of this work, nanostructured P/S incorporated PPy coatings on titanium were demonstrated to be bactericidal against Staphylococcus epidermis after 1 h, and when incorporated with Dex, inhibited macrophage (an inflammatory and immune response cell) growth after 8 and 13 h of in vitro culture. Moreover, nanostructured PPy-drug films coated on titanium enhanced osteoblast (bone forming cells) proliferation, while at the same time, suppressed fibroblast (fibrous tissue forming cells) proliferation for up to 5 days. After electrical stimulation, antimicrobial and anti-inflammatory-coated devices yielded lower bacteria colonies and macrophage growth compared with unincorporated-drug PPy films (controls). This study, thus, suggests that drug incorporated nanostructured PPy coatings on titanium are capable of effectively treating potential orthopedic implant infection and inflammation, and lays the foundation for the further development of local and controllable on-demand drug delivery coatings to improve orthopedic implant efficacy.
authors.affiliation: School of Engineering, Brown University, Providence, Rhode Island 02912, USA.
authors.forename: Sirinrath
authors.initials: S
authors.lastname: Sirivisoot
authors.forename: Rajesh A
authors.initials: RA
authors.lastname: Pareta
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Webster
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology; D000893:Anti-Inflammatory Agents / Q000737:chemistry / Q000494:pharmacology; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D003907:Dexamethasone / Q000737:chemistry / Q000494:pharmacology; D016503:Drug Delivery Systems; D004558:Electric Stimulation; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects; D006801:Humans; D008264:Macrophages / Q000166:cytology / Q000187:drug effects; D008422:Materials Testing; D051379:Mice; D041681:NIH 3T3 Cells; D049329:Nanostructures; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects; D010406:Penicillins / Q000737:chemistry / Q000494:pharmacology; D011108:Polymers / Q000737:chemistry*; D019736:Prostheses and Implants / Q000009:adverse effects; D011758:Pyrroles / Q000737:chemistry*; D013212:Staphylococcus epidermidis / Q000187:drug effects; D013307:Streptomycin / Q000737:chemistry / Q000494:pharmacology; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D000893:Anti-Inflammatory Agents; D020099:Coated Materials, Biocompatible; D010406:Penicillins; D011108:Polymers; D011758:Pyrroles; C067635:polypyrrole; D003907:Dexamethasone; D014025:Titanium; D013307:Streptomycin