RESUMO
Polyether ether ketone (PEEK) is considered the best alternative material for titanium for spinal fusion cage implants due to its low elasticity modulus and radiolucent property. The main problem of PEEK is its bioinert properties. Coating with hydroxyapatite (HA) showed very good improvement in bioactivity of the PEEK implants. However the existing methods for deposition of HA have some disadvantages and damage the PEEK substrate. In our previous study a new method for deposition of HA on PEEK was presented. In this study cell proliferation of mesenchymal stem cell and apatite formation in simulated body fluid (SBF) tests were conducted to probe the effect of this new method in improvement of the bioactivity of PEEK. The mesenchymal stem cell proliferation result showed better cells proliferation on the treated layer in comparison with untreated PEEK. The apatite formation results showed the growth of the HA on the treated PEEK but there was not any sight of the growth of HA on the untreated PEEK even after 2 weeks. The results showed the new method of the HA deposition improved the bioactivity of the treated PEEK in comparison with the bare PEEK.
RESUMO
Ciprofloxacin is mainly absorbed in the proximal areas of the gastrointestinal tract. The purpose of our study was production of floating-bioadhesive tablets to lengthen the stay of drug in its absorption area. Effervescent tablets were made using sodium carboxymethyl cellulose (CMC), hydroxypropyl methylcellulose (HPMC), polyacrylic acid (AA), polymetacrylic acid (MAA), citric acid, and sodium bicarbonate. Tablets with 5% effervescent base had longer lag time than 10%. The type of polymer had no significant effect on the floating lag time. All tablets floated atop the medium for 23-24 hr. Increasing CMC caused higher mucoadhesion than AA (p < 0.05). All formulations showed a Higuchi, non-Fickian release mechanism. Tablets with 10% effervescent base, 80% CMC/20% HPMC, or 80% AA /20% MAA seemed desirable.
