Biocompatible polymeric implants for controlled drug delivery produced by MAPLE

• Published in: Applied surface science 2011-10, Vol.257 (24), p.10780-10788
• Main Authors: Paun, Irina Alexandra, Moldovan, Antoniu, Luculescu, Catalin Romeo, Dinescu, Maria
• Format: Article
• Language: English
• Subjects: Biocompatibility; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Drug delivery; Exact sciences and technology; MAPLE; Physics; Polymers; Thin films
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2011.07.097

► Implants consisting of indomethacin coated with polymeric films were produced by MAPLE. ► The implants were tested in vitro in conditions close to those encountered inside the body. ► The implants containing PEG:PLGA films exhibit enhanced biocompatibility. ► The implants containing PEG:PLGA films offer prolonged release rates of the drug. ► The drug release is controlled by a diffusion mediated mechanism (Higuchi's model). Implants consisting of drug cores coated with polymeric films were developed for delivering drugs in a controlled manner. The polymeric films were produced using matrix assisted pulsed laser evaporation (MAPLE) and consist of poly(lactide-co-glycolide) (PLGA), used individually as well as blended with polyethylene glycol (PEG). Indomethacin (INC) was used as model drug. The implants were tested in vitro (i.e. in conditions similar with those encountered inside the body), for predicting their behavior after implantation at the site of action. To this end, they were immersed in physiological media (i.e. phosphate buffered saline PBS pH 7.4 and blood). At various intervals of PBS immersion (and respectively in blood), the polymeric films coating the drug cores were studied in terms of morphology, chemistry, wettability and blood compatibility. PEG:PLGA film exhibited superior properties as compared to PLGA film, the corresponding implant being thus more suitable for internal use in the human body. In addition, the implant containing PEG:PLGA film provided an efficient and sustained release of the drug. The kinetics of the drug release was consistent with a diffusion mediated mechanism (as revealed by fitting the data with Higuchi's model); the drug was gradually released through the pores formed during PBS immersion. In contrast, the implant containing PLGA film showed poor drug delivery rates and mechanical failure. In this case, fitting the data with Hixson–Crowell model indicated a release mechanism dominated by polymer erosion.