PubMed Health⌕ Search

PubMed · 15918401

Periodontics--tissue engineering and the future.

Abstract

Periodontics has a long history of utilizing advances in science to expand and improve periodontal therapies. Recently the American Academy of Periodontology published the findings of the Contemporary Science Workshop, which conducted state-of-the-art evidence-based reviews of current and emerging areas in periodontics. The findings of this workshop provide the basis for an evidence-based approach to periodontal therapy. While the workshop evaluated all areas of periodontics, it is in the area of tissue engineering that the most exciting advances are becoming a reality.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Gordon L Douglass. 2005. Periodontics--tissue engineering and the future.. https://pubmed.ncbi.nlm.nih.gov/15918401/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Cell type-specific effect of hypoxia and platelet-derived growth factor-BB on extracellular matrix turnover and its consequences for lung remodeling.

Hypoxia is associated with extracellular matrix remodeling in several inflammatory lung diseases, such as fibrosis, chronic obstructive pulmonary disease, and asthma. In a human cell culture model, we assessed whether extracellular matrix modification by hypoxia and platelet-derived growth factor (PDGF) involves the action of matrix metalloproteinases (MMPs) and thereby affects cell proliferation. Expression of MMP and its activity were assessed by zymography and enzyme-linked immunosorbent assay in human lung fibroblasts and pulmonary vascular smooth muscle cells (VSMCs), and synthesis of soluble collagen type I was assessed by enzyme-linked immunosorbent assay. In both cell types, hypoxia up-regulated the expression of MMP-1, -2, and -9 precursors without subsequent activation. MMP-13 was increased by hypoxia only in fibroblasts. PDGF-BB inhibited the synthesis and secretion of all hypoxia-dependent MMP via Erk1/2 mitogen-activated protein (MAP) kinase activation. Hypoxia and PDGF-BB induced synthesis of soluble collagen type I via Erk1/2 and p38 MAP kinase. Hypoxia-induced cell proliferation was blocked by antibodies to PDGF-BB or by inhibition of Erk1/2 but not by the inhibition of MMP or p38 MAP kinase in fibroblasts. In VSMCs, hypoxia-induced proliferation involved Erk1/2 and p38 MAP kinases and was further increased by fibroblast-conditioned medium or soluble collagen type I via Erk1/2. In conclusion, hypoxia controls tissue remodeling and proliferation in a cell type-specific manner. Furthermore, fibroblasts may affect proliferation of VSMC indirectly by inducing the synthesis of soluble collagen type I.

Becaplermin↗

Chondroitin sulfate A chains enhance platelet derived growth factor-mediated signalling in fibrosarcoma cells.

Platelet derived growth factor is involved in the autocrine growth stimulation of malignant cells, the stimulation of angiogenesis and the recruitment and regulation of tumor fibroblasts. PDGF has been shown to physically interact with glycosaminoglycans which are abundant in the fibrosarcoma cell microenvironment. Aim of the present study was to examine the effects of glycosaminoglycans on the mitogenic function of platelet derived growth factor in two human fibrosarcoma cell lines (B6FS, HT1080). For this purpose exogenously added glycosaminoglycans, regulators of endogenous glycosaminoglycan synthesis (sodium chlorate as selective inhibitor and beta-D-xyloside as a stimulator) and specific glycosidases to cleave cell-associated glycosaminoglycans, were utilized. Platelet derived growth factor demonstrated a growth stimulating effect on B6FS, whereas no effect was evident on HT1080 fibrosarcoma cells. Beta-D-xyloside had no effect on the basal level or the platelet derived growth factor-induced cell proliferation, whereas sodium chlorate severely reduced the basal level of proliferation in both cell lines. Significant co-stimulatory effects of chondroitin sulfate A in combination with platelet derived growth factor BB on the growth of HT1080 and B6FS cells were found. The co-stimulatory effect of chondroitin sulfate A was not due to transcriptional up regulation of platelet derived growth factor receptors genes, but rather to more efficient signalling of tyrosine kinase receptors. In conclusion, this study shows that chondroitin sulfate A can enhance the mitogenic activity of platelet-derived growth factor in fibrosarcoma cells utilizing a pathway which involves tyrosine kinases. This result introduces a new modulating role for chondroitin sulfate in signalling pathways critical for cancer growth.

Becaplermin↗

Nano-fibrous scaffold for controlled delivery of recombinant human PDGF-BB.

The localized and temporally controlled delivery of growth factors is key to achieving optimal clinical efficacy. In sophisticated tissue engineering strategies, the biodegradable scaffold is preferred to serve as both a three-dimensional (3-D) substrate and a growth factor delivery vehicle to promote cellular activity and enhance tissue neogenesis. This study presents a novel approach to fabricate tissue engineering scaffolds capable of controlled growth factor delivery whereby growth factor containing microspheres were incorporated into 3-D scaffolds with good mechanical properties, well-interconnected macroporous and nano-fibrous structures. The microspheres were uniformly distributed throughout the nano-fibrous scaffold and their incorporation did not interfere the macro-, micro-, and nanostructures of the scaffold. The release kinetics of platelet-derived growth factor-BB (PDGF-BB) from microspheres and scaffolds was investigated using poly(lactic-co-glycolic acid) (PLGA50) microspheres with different molecular weights (6.5 and 64kDa, respectively) and microsphere-incorporated poly(l-lactic acid) (PLLA) nano-fibrous scaffolds. Incorporation of microspheres into scaffolds significantly reduced the initial burst release. Sustained release from several days to months was achieved through different microspheres in scaffolds. Released PDGF-BB was demonstrated to possess biological activity as evidenced by stimulation of human gingival fibroblast DNA synthesis in vitro. The successful generation of 3-D nano-fibrous scaffold incorporating controlled-release factors indicates significant potential for more complex tissue regeneration.

Becaplermin↗