The Experts below are selected from a list of 37470 Experts worldwide ranked by ideXlab platform

Nureddin Ashammakhi - One of the best experts on this subject based on the ideXlab platform.

  • Tissue reactions to bioabsorbable ciprofloxacin releasing polylactide polyglycolide 80 20 screws in rabbits cranial bone
    Journal of Materials Science: Materials in Medicine, 2006
    Co-Authors: Johanna Tiainen, Ylermi Soini, Pertti Tormala, Timo Waris, Nureddin Ashammakhi, Esa Suokas, Minna Veiranto
    Abstract:

    The aim of this study was to assess Tissue reactions to bioabsorbable self-reinforced ciprofloxacin-releasing polylactide/polyglycolide (SR-PLGA) 80/20 screws in rabbits’ cranial bone. Two screws were implanted in each rabbit, one screw on either side of the sagittal suture (n = 28 rabbits). Animals were sacrificed after 2, 4, 8, 16, 24, 54 and 72 weeks, four animals per group. On histological examination the number of macrophages, giant cells, active osteoblasts and Fibrous Tissue layers were assessed and degradation of the screws was evaluated. At 2 weeks, the highest number of macrophages and giant cells were seen near the heads of the screws. After 4 and 8 weeks, the number of giant cells decreased but that of macrophages decreased from 16 weeks and on. Screws were surrounded by Fibrous Tissue capsule that progressively was growing in thickness by time. Active osteoblasts were seen around the shaft of the screws with the highest number seen at 4 weeks postoperatively. At 16 weeks, compact fragmentation of the screw heads was seen with macrophages seen inside the screw matrices. After 24 weeks, no polarization of the screws was seen. After one year, PLGA screws had been replaced by adipose Tissue, Fibrous Tissue and “foamy macrophages” which had PLGA particles inside them. After 1½ years, the amount of biomaterial remaining had decreased remarkably. The particles of biomaterial were inside “foamy macrophages.” Ciprofloxacin-releasing SR-PLGA 80/20 screws elicited a mild inflammatory reaction but did not interfere with osteoblast activity. No complications were seen when implanted in cranial bone of rabbit.

  • self reinforced polylactide polyglycolide 80 20 screws take more than 1 years to resorb in rabbit cranial bone
    Journal of Biomedical Materials Research Part B, 2004
    Co-Authors: Johanna Tiainen, Ylermi Soini, Pertti Tormala, Timo Waris, Nureddin Ashammakhi
    Abstract:

    The aim of this study was to assess Tissue reactions to bioabsorbable self-reinforced polylactide/polyglycolide (SR-PLGA) 80/20 miniscrews in rabbit cranial bone. One PLGA screw was implanted on one side and one titanium screw on the other side of the sagittal suture (n = 21). Three animals were sacrificed after 2, 4, 8, 16, 24, 54, and 72 weeks. In histological examination the numbers of macrophages, giant cells, active osteoblasts, and Fibrous Tissue layers were assessed and degradation of the bioabsorbable screws was evaluated. After 2 weeks, macrophages were seen near the heads of both screws. After 4 and 8 weeks, the bioabsorbable screws were surrounded by Fibrous Tissue. Osteoblastic activity and groups of several giant cells were seen. After 24 weeks, a significant change in the morphology of the PLGA screws had occurred. Osteoblastic activity and the amount of giant cells had decreased. After 1 year, some PLGA biomaterial was still present. PLGA screws had been replaced by adipose Tissue, Fibrous Tissue, and "foamy macrophages" that had PLGA particles inside them. After 1(1/2) years, the amount of biomaterial remaining had decreased remarkably. The particles of biomaterial were inside foamy macrophages. SR-PLGA 80/20 screws are biocompatible and have no clinically manifested complications when used in the cranial bone of rabbits. No contraindications as regards their clinical use in craniofacial surgery was found when these screws were studied in the cranial bones of rabbits.

Glenn D Prestwich - One of the best experts on this subject based on the ideXlab platform.

  • disulfide crosslinked hyaluronan gelatin sponge growth of Fibrous Tissue in vivo
    Journal of Biomedical Materials Research Part A, 2004
    Co-Authors: Steven D Gray, Glenn D Prestwich
    Abstract:

    The modification of hyaluronan (HA) and gelatin using dithiobis(propanoic dihydrazide) (DTP) has provided two thiolated macromolecular components of the extracellular matrix (ECM), specifically HA–DTPH and gelatin–DTPH. Blends of these thiolated ECM components were crosslinked in air to form hydrogels that were interpenetrating disulfide-crosslinked networks. Lyophilization of the hydrogels afforded sponge-like macroporous scaffolds suitable for cell attachment and proliferation. Increasing percentages of gelatin–DTPH (0, 25, 50, and 75%) were blended with HA–DTPH, and the resulting sponges were evaluated in vitro and in vivo as scaffolds for Tissue engineering by seeding with human tracheal scar (HTS) fibroblasts. While cells failed to attach and grow in HA-only sponges, the gelatin-modified HA sponges promoted cell adhesion, proliferation, and spreading in vitro. Optimal attachment and growth was observed with 50% gelatin–HA sponges. Cell attachment to the gelatin–HA sponge could be blocked by preincubation of cells with a soluble fibronectin peptide Gly-Arg-Gly-Asp (GRGD). Finally, HTS fibroblast-seeded gelatin–HA sponges were implanted into the flanks of nude mice and evaluated at 2 and 8 weeks postimplantation. The sponges were fully biocompatible and new Fibrous Tissue formed, gradually replacing the sponge-like scaffold. The gelatin–HA sponges act as synthetic, macroporous, covalent mimics of the ECM and constitute novel scaffolds for cell growth and Tissue augmentation. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 68A: 142–149, 2004

  • disulfide crosslinked hyaluronan gelatin sponge growth of Fibrous Tissue in vivo
    Journal of Biomedical Materials Research Part A, 2004
    Co-Authors: Yanchun Liu, Steven D Gray, Xiao Zheng Shu, Glenn D Prestwich
    Abstract:

    The modification of hyaluronan (HA) and gelatin using dithiobis(propanoic dihydrazide) (DTP) has provided two thiolated macromolecular components of the extracellular matrix (ECM), specifically HA-DTPH and gelatin-DTPH. Blends of these thiolated ECM components were crosslinked in air to form hydrogels that were interpenetrating disulfide-crosslinked networks. Lyophilization of the hydrogels afforded sponge-like macroporous scaffolds suitable for cell attachment and proliferation. Increasing percentages of gelatin-DTPH (0, 25, 50, and 75%) were blended with HA-DTPH, and the resulting sponges were evaluated in vitro and in vivo as scaffolds for Tissue engineering by seeding with human tracheal scar (HTS) fibroblasts. While cells failed to attach and grow in HA-only sponges, the gelatin-modified HA sponges promoted cell adhesion, proliferation, and spreading in vitro. Optimal attachment and growth was observed with 50% gelatin-HA sponges. Cell attachment to the gelatin-HA sponge could be blocked by preincubation of cells with a soluble fibronectin peptide Gly-Arg-Gly-Asp (GRGD). Finally, HTS fibroblast-seeded gelatin-HA sponges were implanted into the flanks of nude mice and evaluated at 2 and 8 weeks postimplantation. The sponges were fully biocompatible and new Fibrous Tissue formed, gradually replacing the sponge-like scaffold. The gelatin-HA sponges act as synthetic, macroporous, covalent mimics of the ECM and constitute novel scaffolds for cell growth and Tissue augmentation.

Steven D Gray - One of the best experts on this subject based on the ideXlab platform.

  • disulfide crosslinked hyaluronan gelatin sponge growth of Fibrous Tissue in vivo
    Journal of Biomedical Materials Research Part A, 2004
    Co-Authors: Steven D Gray, Glenn D Prestwich
    Abstract:

    The modification of hyaluronan (HA) and gelatin using dithiobis(propanoic dihydrazide) (DTP) has provided two thiolated macromolecular components of the extracellular matrix (ECM), specifically HA–DTPH and gelatin–DTPH. Blends of these thiolated ECM components were crosslinked in air to form hydrogels that were interpenetrating disulfide-crosslinked networks. Lyophilization of the hydrogels afforded sponge-like macroporous scaffolds suitable for cell attachment and proliferation. Increasing percentages of gelatin–DTPH (0, 25, 50, and 75%) were blended with HA–DTPH, and the resulting sponges were evaluated in vitro and in vivo as scaffolds for Tissue engineering by seeding with human tracheal scar (HTS) fibroblasts. While cells failed to attach and grow in HA-only sponges, the gelatin-modified HA sponges promoted cell adhesion, proliferation, and spreading in vitro. Optimal attachment and growth was observed with 50% gelatin–HA sponges. Cell attachment to the gelatin–HA sponge could be blocked by preincubation of cells with a soluble fibronectin peptide Gly-Arg-Gly-Asp (GRGD). Finally, HTS fibroblast-seeded gelatin–HA sponges were implanted into the flanks of nude mice and evaluated at 2 and 8 weeks postimplantation. The sponges were fully biocompatible and new Fibrous Tissue formed, gradually replacing the sponge-like scaffold. The gelatin–HA sponges act as synthetic, macroporous, covalent mimics of the ECM and constitute novel scaffolds for cell growth and Tissue augmentation. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 68A: 142–149, 2004

  • disulfide crosslinked hyaluronan gelatin sponge growth of Fibrous Tissue in vivo
    Journal of Biomedical Materials Research Part A, 2004
    Co-Authors: Yanchun Liu, Steven D Gray, Xiao Zheng Shu, Glenn D Prestwich
    Abstract:

    The modification of hyaluronan (HA) and gelatin using dithiobis(propanoic dihydrazide) (DTP) has provided two thiolated macromolecular components of the extracellular matrix (ECM), specifically HA-DTPH and gelatin-DTPH. Blends of these thiolated ECM components were crosslinked in air to form hydrogels that were interpenetrating disulfide-crosslinked networks. Lyophilization of the hydrogels afforded sponge-like macroporous scaffolds suitable for cell attachment and proliferation. Increasing percentages of gelatin-DTPH (0, 25, 50, and 75%) were blended with HA-DTPH, and the resulting sponges were evaluated in vitro and in vivo as scaffolds for Tissue engineering by seeding with human tracheal scar (HTS) fibroblasts. While cells failed to attach and grow in HA-only sponges, the gelatin-modified HA sponges promoted cell adhesion, proliferation, and spreading in vitro. Optimal attachment and growth was observed with 50% gelatin-HA sponges. Cell attachment to the gelatin-HA sponge could be blocked by preincubation of cells with a soluble fibronectin peptide Gly-Arg-Gly-Asp (GRGD). Finally, HTS fibroblast-seeded gelatin-HA sponges were implanted into the flanks of nude mice and evaluated at 2 and 8 weeks postimplantation. The sponges were fully biocompatible and new Fibrous Tissue formed, gradually replacing the sponge-like scaffold. The gelatin-HA sponges act as synthetic, macroporous, covalent mimics of the ECM and constitute novel scaffolds for cell growth and Tissue augmentation.

Johanna Tiainen - One of the best experts on this subject based on the ideXlab platform.

  • Tissue reactions to bioabsorbable ciprofloxacin releasing polylactide polyglycolide 80 20 screws in rabbits cranial bone
    Journal of Materials Science: Materials in Medicine, 2006
    Co-Authors: Johanna Tiainen, Ylermi Soini, Pertti Tormala, Timo Waris, Nureddin Ashammakhi, Esa Suokas, Minna Veiranto
    Abstract:

    The aim of this study was to assess Tissue reactions to bioabsorbable self-reinforced ciprofloxacin-releasing polylactide/polyglycolide (SR-PLGA) 80/20 screws in rabbits’ cranial bone. Two screws were implanted in each rabbit, one screw on either side of the sagittal suture (n = 28 rabbits). Animals were sacrificed after 2, 4, 8, 16, 24, 54 and 72 weeks, four animals per group. On histological examination the number of macrophages, giant cells, active osteoblasts and Fibrous Tissue layers were assessed and degradation of the screws was evaluated. At 2 weeks, the highest number of macrophages and giant cells were seen near the heads of the screws. After 4 and 8 weeks, the number of giant cells decreased but that of macrophages decreased from 16 weeks and on. Screws were surrounded by Fibrous Tissue capsule that progressively was growing in thickness by time. Active osteoblasts were seen around the shaft of the screws with the highest number seen at 4 weeks postoperatively. At 16 weeks, compact fragmentation of the screw heads was seen with macrophages seen inside the screw matrices. After 24 weeks, no polarization of the screws was seen. After one year, PLGA screws had been replaced by adipose Tissue, Fibrous Tissue and “foamy macrophages” which had PLGA particles inside them. After 1½ years, the amount of biomaterial remaining had decreased remarkably. The particles of biomaterial were inside “foamy macrophages.” Ciprofloxacin-releasing SR-PLGA 80/20 screws elicited a mild inflammatory reaction but did not interfere with osteoblast activity. No complications were seen when implanted in cranial bone of rabbit.

  • self reinforced polylactide polyglycolide 80 20 screws take more than 1 years to resorb in rabbit cranial bone
    Journal of Biomedical Materials Research Part B, 2004
    Co-Authors: Johanna Tiainen, Ylermi Soini, Pertti Tormala, Timo Waris, Nureddin Ashammakhi
    Abstract:

    The aim of this study was to assess Tissue reactions to bioabsorbable self-reinforced polylactide/polyglycolide (SR-PLGA) 80/20 miniscrews in rabbit cranial bone. One PLGA screw was implanted on one side and one titanium screw on the other side of the sagittal suture (n = 21). Three animals were sacrificed after 2, 4, 8, 16, 24, 54, and 72 weeks. In histological examination the numbers of macrophages, giant cells, active osteoblasts, and Fibrous Tissue layers were assessed and degradation of the bioabsorbable screws was evaluated. After 2 weeks, macrophages were seen near the heads of both screws. After 4 and 8 weeks, the bioabsorbable screws were surrounded by Fibrous Tissue. Osteoblastic activity and groups of several giant cells were seen. After 24 weeks, a significant change in the morphology of the PLGA screws had occurred. Osteoblastic activity and the amount of giant cells had decreased. After 1 year, some PLGA biomaterial was still present. PLGA screws had been replaced by adipose Tissue, Fibrous Tissue, and "foamy macrophages" that had PLGA particles inside them. After 1(1/2) years, the amount of biomaterial remaining had decreased remarkably. The particles of biomaterial were inside foamy macrophages. SR-PLGA 80/20 screws are biocompatible and have no clinically manifested complications when used in the cranial bone of rabbits. No contraindications as regards their clinical use in craniofacial surgery was found when these screws were studied in the cranial bones of rabbits.

Yanchun Liu - One of the best experts on this subject based on the ideXlab platform.

  • disulfide crosslinked hyaluronan gelatin sponge growth of Fibrous Tissue in vivo
    Journal of Biomedical Materials Research Part A, 2004
    Co-Authors: Yanchun Liu, Steven D Gray, Xiao Zheng Shu, Glenn D Prestwich
    Abstract:

    The modification of hyaluronan (HA) and gelatin using dithiobis(propanoic dihydrazide) (DTP) has provided two thiolated macromolecular components of the extracellular matrix (ECM), specifically HA-DTPH and gelatin-DTPH. Blends of these thiolated ECM components were crosslinked in air to form hydrogels that were interpenetrating disulfide-crosslinked networks. Lyophilization of the hydrogels afforded sponge-like macroporous scaffolds suitable for cell attachment and proliferation. Increasing percentages of gelatin-DTPH (0, 25, 50, and 75%) were blended with HA-DTPH, and the resulting sponges were evaluated in vitro and in vivo as scaffolds for Tissue engineering by seeding with human tracheal scar (HTS) fibroblasts. While cells failed to attach and grow in HA-only sponges, the gelatin-modified HA sponges promoted cell adhesion, proliferation, and spreading in vitro. Optimal attachment and growth was observed with 50% gelatin-HA sponges. Cell attachment to the gelatin-HA sponge could be blocked by preincubation of cells with a soluble fibronectin peptide Gly-Arg-Gly-Asp (GRGD). Finally, HTS fibroblast-seeded gelatin-HA sponges were implanted into the flanks of nude mice and evaluated at 2 and 8 weeks postimplantation. The sponges were fully biocompatible and new Fibrous Tissue formed, gradually replacing the sponge-like scaffold. The gelatin-HA sponges act as synthetic, macroporous, covalent mimics of the ECM and constitute novel scaffolds for cell growth and Tissue augmentation.