A combination of platelet-derived and insulin-like growth factors enhances periodontal regeneration

Abstract The combination of platelet-derived growth factor (PDGF) and insulin-like growth factor one (IGF-1) has previously been shown to enhance repair of soft tissue wounds. Here we report initial observations following application of PDGF and IGF-1 to periodontitis-affected teeth in beagle dogs, 1 μg of PDGF and IGF-1 in an aqueous gel was applied to the root surfaces of test teeth following open flap debridement. Control sites received the gel alone. Block biopsies of the teeth and surrounding bone were taken 2 weeks after treatment. Histologic analyses of control specimens revealed a long junctional epithelial attachment, and no new bone or cementum formation. In contrast, growth factor treated sites exhibited significant amounts of new bone and cementum formation. A nearly continuous layer of osteoblasts lined the newly formed bone, and there was a dense cellular “front” at the coronal extent of the new bone. These preliminary results suggest that in vivo application of the combination of PDGF and IGF-1 may enhance regeneration of the periodontal structures.     

血小板衍生生长因子-BB与胰岛素样生长因子-Ⅰ联合应用对大鼠正畸牙牙周膜细胞整合素β3表达的影响

目的 观察血小板衍生生长因子-BB(PDGF-BB)与胰岛素样生长因子-Ⅰ(IGF-Ⅰ)联合应用对大鼠正畸牙压力侧牙周膜细胞(PDLCs)中整合素β<,3>蛋白表达的影响.方法 建立SD大鼠正畸牙移动模型,隔日于正畸牙颊侧牙龈黏膜下单独或联合注射10ng PDGF-BB及200ng IGF-Ⅰ,加力10d后处死大鼠,取...     

Platelet-derived and insulin-like growth factors stimulate regeneration of periodontal attachment in monkeys

Regeneration of cementum, ligament, bone and new attachment was achieved by introducing mixtures of recombinant human platelet-derived growth factor and insulin-like growth factor into debrided lesions of experimentally induced periodontitis in monkeys. This growth factor therapeutic regimen induced the regeneration of nearly 50% of the lost attachment within 4 weeks. New attachment in some cases included regeneration of horizontally resorbed interdental septa. These observations suggest that predictable, clinically significant gains in new attachment may be possible through the use of highly purified human recombinant growth factors delivered to debrided lesions of adult periodontitis in appropriate, inert carrier vehicles.     

Impaired early bone formation in periodontal fenestration defects in dogs following application of insulin-like growth factor (II). Basic fibroblast growth factor and transforming growth factor beta 1

Abstract. Effects of a topically applied growth factor combination on fibroblast migration, collagen fiber formation and bone regeneration were studied in standardized periodontal defects in 4 beagle dogs. Following elevation of facial mucoperiosteal flaps, fenestration defects, 3 mm in diameter, were made through the cortical bone and into the dentin of maxillary and mandibular teeth. Collagen sponges, impregnated with 200 ng insulin-like growth factor II, 20 ng basic fibroblast growth factor and 6 ng transforming growth factor beta 1 were fitted to defects randomly in right or left quadrants and the flaps repositioned and sutured. Contralateral control defects received the collagen with vehicle only. Experimental procedures were staggered to allow observations of healing 3, 7, 10, and 14 days after surgery. Histometric analysis showed no differences in fibroblast and collagen density between control and growth factor defects. Bone regeneration was significantly greater in control than in growth factor defects 10 and 14 days after surgery. The rate of healing generally appeared more affected by intra-dog variations or procedural variations than by the growth factor combination.     

Immunohistochemical detection of insulin-like growth factors, platelet-derived growth factor, and their receptors in ameloblastic tumors

BACKGROUND: To evaluate the roles of growth factors in oncogenesis and cytodifferentiation of odontogenic tumors, expression of insulin-like growth factors (IGFs), platelet-derived growth factor (PDGF), and their receptors was analyzed in ameloblastic tumors as well as in tooth germs. METHODS: Tissue specimens of 10 tooth germs, 47 ameloblastomas, and five malignant ameloblastic tumors were examined immunohistochemically with the use of antibodies against IGF-I, IGF-II, IGF-I receptor (IGF-IR), PDGF A-chain, PDGF B-chain, PDGF alpha-receptor, and PDGF beta-receptor. RESULTS: Immunohistochemical reactivity for IGFs, PDGF chains, and their receptors was detected predominantly in odontogenic epithelial cells near the basement membrane in tooth germs and in benign and malignant ameloblastic tumors. The expression levels of IGF-II and PDGF chains were significantly higher in ameloblastic tumors than in tooth germs. Malignant ameloblastic tumors showed higher reactivity for PDGF chains than benign ameloblastomas and higher reactivity for platelet-derived growth factor receptors than tooth germs. The expression levels of PDGF chains were significantly higher in follicular ameloblastomas than in plexiform ameloblastomas. Desmoplastic ameloblastomas showed higher expression of IGFs and IGF-IR when compared with other ameloblastoma subtypes. CONCLUSION: Expression of IGFs, PDGF, and their receptors in tooth germs and ameloblastic tumors suggests that these growth factor signals contribute to cell proliferation or survival in both normal and neoplastic odontogenic tissues. Expression of these molecules in odontogenic tissues possibly affects interactions with the bone microenvironment during tooth development and intraosseous progression of ameloblastic tumors. Altered expression of the ligands and receptors in ameloblastic tumors may be involved in oncogenesis, malignant potential, and tumor cell differentiation.     

血小板衍化生长因子-BB和碱性成纤维细胞生长因子对人牙周膜细胞增殖的影响

目的探讨重组人血小板衍生生长因子（rhPDGF）-BB和重组人碱性成纤维细胞生长因子（rh—bFGF）对人牙周膜细胞（PDLC）增殖的影响。方法原代培养人PDLC,应用甲噻唑四唑氮（MTT）比色和流式细胞仪检测rh-PDGF-BB和rh-bFGF单独及联合作用下细胞的增殖能力和增殖指数。结果rhPDGF-BB和rh-bFGF联合作用后,PDLC增殖能力提高,活性增强。其中,10μg&#183;L^-1的rhPDGF—BB加10μg&#183;L^-1的bFGF为最佳显效质量浓度,第3天为最佳显效时间。结论PDGF—BB和bFGF联合能更显著促进人PDLC的增殖并且具有明显的协同效应。     

An immunohistochemical study of matrix molecules associated with barrier membrane-mediated periodontal wound healing

Guided tissue regeneration (GTR) is a clinical procedure developed to facilitate periodontal regeneration by using barrier membranes to selectively promote the repopulation of a periodontal defect by periodontal ligament and bone cells at the expense of epithelial and gingival connective tissue cells. The aim of this study was to gain insight into the biological events occurring during membrane mediated periodontal wound healing by examining the immunohistochemical expression of a number of extracellular matrix components in tissues treated via the GTR technique. Experimental periodontal defects were created around the second premolar tooth in 4 dogs and wound closure was achieved by application of expanded polytetrafluoroethylene membranes around each tooth and flap positioning coronal to the cementoenamel junction. The dogs were sacrificed after a 4-wk healing period, block dissections of the part of the mandible containing the experimental tooth were obtained and paraffin sections were prepared. Using standard immunohistochemical techniques, the sections were stained with a monoclonal antibody against bone morphogenetic proteins 2 and 4 (BMP-2 and -4) and polyclonal antibodies against collagen I, collagen II, decorin, biglycan, bone sialoprotein, osteopontin and osteocalcin. Collagen I was predominantly localized within the regenerating bone, whereas collagen III staining was more abundant in the soft connective tissues of the defect. Decorin and biglycan staining was faint within the extracellular matrix of the regenerating defect, although both proteoglycans exhibited intense intracellular localization within some of the cells inhabiting the defect. The staining for BMP-2 and -4 was weak within the bone but strong within the extracellular matrix of the regenerating soft tissue. Osteopontin and bone sialoprotein were strongly localized in the regenerating bone and cementum found within the defect. Osteocalcin staining was present in both the regenerating and mature cementum and associated cementoblasts, and it was relatively weaker in the regenerating bone compared to the mature bone. The observed pattern of immunolocalization of the extracellular matrix macromolecules suggests that the heterogeneous cell population filling the GTR wound had created an environment that was conducive to periodontal regeneration.     

Immunolocalization of platelet-derived growth factor A and B chains and PDGF-α and β receptors in human gingival wounds

Platelet-derived growth factor (PDGF) is a polypeptide growth factor which has been implicated as a major mitogen involved in wound healing. The PDGF appears to promote periodontal regeneration; however, its distribution in gingival tissues is not known and how it participates in gingival wound healing is unclear. Using highly specific antibodies we have studied the distribution of PDGF A and B chains and α- and β-PDGF receptors in healing human gingival wounds. Wounds were created by making a 0.75 mm deep incision in the papilla of healthy human gingiva and biopsies were obtained from the same site after 8 h and 1, 3, 7, 14 and 21 d. Frozen sections were immunostained with affinity purified antibodies. The results showed that both epithelium and fibrin clot manifested positive immunostaining for anti-PDGF-A and B-chain antibodies. Staining was present in unwounded and wounded epithelia, and in the fibrin clot it appeared to be more intense for the PDGF-A chain. Blood vessels in connective tissue were also positive while other areas were largely negative. No significant staining was detectable in healthy tissues for anti-PDGF-α or -β receptor antibodies. However, the wound site began to manifest positive immunostaining for anti-β-receptor antibody after 3 d of healing, became maximal at 7d, and then decreased. Our data indicate, but do not prove, that gingival epithelium may be a source of PDGF A and B chains and that the A chain may have a more prominent role to play during early stages of healing. Expression of PDGF β-receptor appears later at the wound site, indicating that the PDGF B isomer may regulate later wound healing events.     

生长因子与牙周组织再生

促进功能性牙周组织再生,重建牙槽骨、牙骨质和牙周膜的生理结构是牙周病治疗的最终目的。生长因子在牙周组织再生过程中起着重要作用,本文就牙周组织再生中生长因子的作用及其临床应用、控释技术等作一综述。     

The combination of purified recombinant human platelet-derived growth factor-BB and equine particulate bone graft for periodontal regeneration

Background: The objective of this study is to evaluate the potential for periodontal regeneration of a critical‐sized defect with the application of recombinant human platelet‐derived growth factor (rhPDGF‐BB) combined with either a particulate equine or a β‐tricalcium phosphate (β‐TCP) matrix. Methods: Critical‐sized intrabony 2‐wall defects were created bilaterally on the distal surface of the second premolar and the mesial surface of the first molar in nine hounds. Twelve defects received rhPDGF‐BB/equine treatment, 12 defects received rhPDGF‐BB/β‐TCP treatment, and the remaining 12 sites served as sham‐surgery controls. The animals were sacrificed after a 10‐week healing period. Results: Clinical healing was uneventful without obvious signs of overt gingival inflammation. Histologic and histomorphometric analyses revealed statistically that there were differences among the three groups in terms of new bone formation (P <0.001). The amount of test material for both rhPDGF‐BB/equine and rhPDGF‐BB/β‐TCP groups was comparable, but the amount of newly formed bone was significantly higher (P <0.01) in favor of the rhPDGF‐BB/equine group. The amount of new cementum formed for the rhPDGF‐BB/equine group (4.8 ± 1.3 mm) was significantly higher (P =0.001) than the sham‐surgery control group (1.7 ± 1.9 mm). Conclusion: Both rhPDGF‐BB/equine and rhPDGF‐BB/β‐TCP have the potential to support the regeneration of the periodontal attachment apparatus.     

Periodontal repair in dogs: effect of rhBMP-2 concentration on regeneration of alveolar bone and periodontal attachment

The objective of this study was to evaluate the effect of recombinant human bone morphogenetic protein-2 (rhBMP-2) concentration on regeneration of alveolar bone and cementum, and on associated root resorption and ankylosis. Contralateral, critical size, supra-alveolar, periodontal defects were surgically produced and immediately implanted with rhBMP-2 in an absorbable collagen sponge (ACS) carrier in 8, young adult, male, beagle dogs. 6 animals received rhBMP-2/ACS (rhBMP-2 at 0.05, 0.10, or 0.20 mg/mL; total construct volume/defect approximately 4.0 mL) in contralateral defects following an incomplete block design. 2 animals received rhBMP-2/ACS (rhBMP-2 at 0 and 0.10 mg/mL) in contralateral defects (controls). The animals were euthanised at 8 weeks post-surgery and block sections of the defects were collected for histologic and histometric analysis. Supra-alveolar periodontal defects receiving rhBMP-2 at 0.05, 0.10, or 0.20 mg/ml exhibited extensive alveolar regeneration comprising 86%, 96%, and 88% of the defect height, respectively. Cementum regeneration encompassed 8%, 6%, and 8% of the defect height, respectively. Root resorption was observed for all rhBMP-2 concentrations. Ankylosis was observed in almost all teeth receiving rhBMP-2. Control defects without rhBMP-2 exhibited limited, if any, evidence of alveolar bone and cementum regeneration, root resorption, or ankylosis. Within the selected rhBMP-2 concentration and observation interval, there appear to be no meaningful differences in regeneration of alveolar bone and cementum. There also appear to be no significant differences in the incidence and extent of root resorption and ankylosis, though there may be a positive correlation with rhBMP-2 concentration.     

牛血小板衍化生长因子对人牙周膜成纤维细胞的生物学效应

目的：观察在牛血小板衍化生长因子作用下人牙周膜成纤维细胞ＤＮＡ和胶原蛋白合成的情况。方法：采用体外细胞培养技术和核素掺入法。结果：２０ｎｇ／ｍｌ～６０ｎｇ／ｍｌ牛血小板衍化生长因子可明显促进人牙周膜成纤维细胞ＤＮＡ合成，４０ｎｇ／ｍｌ浓度使细胞ＤＮＡ合成在２４ｈ达最高峰；对细胞的胶原蛋白合成无明显促进作用。结论：牛血小板衍化生长因子对人牙周膜成纤维细胞ＤＮＡ合成有促进作用，在牙周组织的创伤修复中可能起重要作用。     

生长因子在牙周组织再生中的有效释放方式

生长因子在牙周组织再生过程中起重要的作用,是组织修复的基本调节者,但其在体内半衰期短,直接应用达不到预期的效果。为此,国内外众多学者正致力于寻找一种能够使生长因子持续高效发挥作用的方法,其中,制备生长因子缓释微球,利用智能控释载体材料,使生长因子缓慢而持续地释放;采用基因工程技术,通过载体将生长因子的目的基因整合入目的细胞,也能使生长因子在细胞和组织中持续局限性地表达。这两种方法均有望解决生长因子不能有效发挥其生物学作用这一难题。本文就建立生长因子缓释和控释系统以及基因工程技术等研究进展作一综述。     

Effect of two delivery systems for recombinant human bone morphogenetic protein-2 on periodontal regeneration in vivo

Resorbable collagen membranes for guided tissue regeneration in periodontal therapy have shown promise but are not osteoinductive. As recombinant human bone morphogenetic protein-2 (rhBMP-2) is known to have an affinity for collagen, the use of this osteoinductive agent incorporated into a collagen vehicle may act as a suitable carrier to promote periodontal regeneration. The aim of this study was to investigate the effects of two different collagen delivery systems for rhBMP-2 in rat periodontal fenestration defects. Using the collagen membrane delivery system, 3 groups of adult Wistar rats which had surgical defects created on the right side of the mandible involving the removal of bone and exposure of the molar roots were treated with either rhBMP-2 in collagen membrane (BMPm) (n= 12 animals), or collagen membrane only (COLm) (n = 12), or were left untreated (UN) (n= 14). Using the collagen gel delivery system, surgical defects were treated with either rhBMP-2 incorporated in a collagen gel carrier (BMPg) (n = 5) or had collagen gel only (COLg) (n = 6). Animals were killed 10 d postoperatively and tissues processed for histology. New bone formation was significantly greater in BMPg compared with both BMPm and controls (p<0.05). However, new cementum formation was significantly greater in BMPm (721 ± 166 μm², mean ± SE) compared with COLm, COLg and UN (p<0.02) (190±44μm², 327±114 μm² and 172 ± 33 μm², respectively) and more than 1.5 times BMPg (451 ± 158 μm²). In conclusion, both carrier systems for rhBMP-2 significantly increased new bone formation compared with controls during the early stages of periodontal wound healing. However, the more slowly dissolving collagen membrane carrier system for rhBMP-2 produced significantly greater new cementum compared with the collagen gel carrier, suggesting that a more prolonged exposure of rhBMP-2 is required to increase cementogenesis.     

三维培养模型中胰岛素样生长因子-I对人牙周膜细胞增殖及碱性磷酸酶活性的影响

目的 了解胰岛素样生长因子-I(IGF-I)在三维培养条件下对人牙周膜细胞(hPDLCs)增殖及碱性磷酸酶(ALP)活性的影响.方法 通过组织块法分离培养hPDLCs.采用旋转细胞培养系统(RCCS)建立三维培养环境.将细胞分为4组,分别为阴性对照组、阳性对照组(三维培养组、IGF-I组)、实验组(三维培养加IGF-I...     

Effect of two delivery systems for recombinant human bone morphogenetic protein-2 on periodontal regeneration in vivo

Resorbable collagen membranes for guided tissue regeneration in periodontal therapy have shown promise but are not osteoinductive. As recombinant human bone morphogenetic protein-2 (rhBMP-2) is known to have an affinity for collagen, the use of this osteoinductive agent incorporated into a collagen vehicle may act as a suitable carrier to promote periodontal regeneration. The aim of this study was to investigate the effects of two different collagen delivery systems for rhBMP-2 in rat periodontal fenestration defects. Using the collagen membrane delivery system, 3 groups of adult Wistar rats which had surgical defects created on the right side of the mandible involving the removal of bone and exposure of the molar roots were treated with either rhBMP-2 in collagen membrane (BMPm) (n = 12 animals), or collagen membrane only (COLm) (n = 12), or were left untreated (UN) (n = 14). Using the collagen gel delivery system, surgical defects were treated with either rhBMP-2 incorporated in a collagen gel carrier (BMPg) (n = 5) or had collagen gel only (COLg) (n = 6). Animals were killed 10 d postoperatively and tissues processed for histology. New bone formation was significantly greater in BMPg compared with both BMPm and controls (p<0.05). However, new cementum formation was significantly greater in BMPm (721 ± 166 μm², mean ± SE) compared with COLm, COLg and UN (p<0.02) (190 ± 44 μm², 327±114 μm² and 172 ± 33 μm², respectively) and more than 1.5 times BMPg (451 ± 158 μm²). In conclusion, both carrier systems for rhBMP-2 significantly increased new bone formation compared with controls during the early stages of periodontal wound healing. However, the more slowly dissolving collagen membrane carrier system for rhBMP-2 produced significantly greater new cementum compared with the collagen gel carrier, suggesting that a more prolonged exposure of rhBMP-2 is required to increase cementogenesis.     

Effects of Delta12-prostaglandin J2 on bone regeneration and growth factor expression in rats

OBJECTIVES: Cyclopentenone prostaglandins have been shown to promote osteoblast differentiation in vitro. The aim of this study was to examine in a rat model the effects of local delivery of Delta(12)-prostaglandin J(2) (Delta(12)-PGJ(2)) on new bone formation and growth factor expression in (i) cortical defects and (ii) around titanium implants. MATERIAL AND METHODS: Standardized transcortical defects were prepared bilaterally in the femur of 28 male Wistar rats. Ten microliters of Delta(12)-PGJ(2) at 4 concentrations (10(-9), 10(-7), 10(-5) and 10(-3) mol/l) in a collagen vehicle were delivered inside a half-cylindrical titanium chamber fixed over the defect. Contralateral defects served as vehicle controls. Ten days after surgery, the amount of new bone formation in the cortical defect area was determined by histomorphometry and expression of platelet-derived growth factor (PDGF)-A and -B, insulin-like growth factor (IGF)-I/II, bone morphogenetic protein (BMP)-2 and -6 was examined by immunohistochemistry. In an additional six rats, 24 titanium implants were inserted into the femur. Five microliters of carboxymethylcellulose alone (control) or with Delta(12)-PGJ(2) (10(-5) and 10(-3) mol/l) were delivered into surgically prepared beds prior to implant installation. RESULTS: Delta(12)-PGJ(2) (10(-5) and 10(-3) mol/l) significantly enhanced new bone formation (33%, P<0.05) compared with control cortical defects. Delivery of Delta(12)-PGJ(2) at 10(-3) mol/l significantly increased PDGF-A and -B and BMP-2 and -6 protein expression (P<0.05) compared with control defects. No significant difference was found in IGF-I/II expression compared with controls. Administration of Delta(12)-PGJ(2) also significantly increased endosteal new bone formation around implants compared with controls. CONCLUSION: Local delivery of Delta(12)-PGJ(2) promoted new bone formation in the cortical defect area and around titanium implants. Enhanced expression of BMP-2 and -6 as well as PDGF-A and -B may be involved in Delta(12)-PGJ(2)-induced new bone formation.