title: Poly(L-lactide)acid/alginate composite membranes for guided tissue regeneration.
abstract: The barrier membranes for guided tissue regeneration (GTR) to treat bone defects have to satisfy the criteria of biocompatibility, cell-occlusiveness, space-making, tissue integration and clinical manageability. In this study a system constituted of a poly(L-lactide) acid (PLLA) asymmetric membrane combined with an alginate film was prepared. The PLLA membrane functions to both support the alginate film and separate the soft tissue; the alginate film is intended to act as potential vehicle for the growth factors to promote osteogenesis. The structural, morphological, and mechanical properties of the bilamellar membrane and its stability in culture medium were evaluated. Moreover, the feasibility of using the alginate membranes as controlled-release delivery vehicles of TGF-beta was monitored. Finally, the bacterial adhesion and permeability of Streptococcus mutans, selected for the high adhesive affinity, were monitored. The results showed that the surfaces of the alginate side, to be used in contact with the bone defect, were rougher than PLLA ones. When in contact with complete culture medium, the PLLA-alginate membrane retained its mechanical and structural properties for more than 100 days. Then, the degradation processes occurred but the membrane continued to be stable and manageable for 6 months. Growth factors such as TGF-beta can be incorporated into alginate membranes functioning as drug delivery vehicle, and retain the biological activity when tested in an in vitro model system. The obtained membrane acted as a barrier to the passage of S. mutans bacteria and showed to promote a lower bacterial adhesion with respect to commercial GTR membranes.
authors.affiliation: PASTIS-CNRSM S.C.p.A., Biomaterials Unit, SS 7 Appia km 7+300, 72100 Brindisi, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Milella
authors.forename: G
authors.initials: G
authors.lastname: Barra
authors.forename: P A
authors.initials: PA
authors.lastname: Ramires
authors.forename: G
authors.initials: G
authors.lastname: Leo
authors.forename: P
authors.initials: P
authors.lastname: Aversa
authors.forename: A
authors.initials: A
authors.lastname: Romito
mesh_terms: D000464:Alginates / Q000737:chemistry*; D000469:Alkaline Phosphatase / Q000378:metabolism; D001672:Biocompatible Materials / Q000737:chemistry* / Q000378:metabolism; D002151:Calorimetry; D002448:Cell Adhesion / Q000502:physiology; D048091:Guided Tissue Regeneration; D019344:Lactic Acid / Q000737:chemistry*; D008567:Membranes, Artificial; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D010006:Osteoblasts / Q000378:metabolism; D011091:Polyesters; D011108:Polymers / Q000737:chemistry*; D013295:Streptococcus mutans / Q000502:physiology; D013696:Temperature; D016212:Transforming Growth Factor beta / Q000737:chemistry / Q000378:metabolism; D014961:X-Ray Diffraction
chemical_list: D000464:Alginates; D001672:Biocompatible Materials; D008567:Membranes, Artificial; D011091:Polyesters; D011108:Polymers; D016212:Transforming Growth Factor beta; D019344:Lactic Acid; C033616:poly(lactide); D000469:Alkaline Phosphatase