Recombinant Human Platelet-derived Growth Factor Research Articles

Efficacy of topical recombinant human platelet-derived growth factor for treatment of diabetic lower-extremity ulcers: Systematic review and meta-analysis

ObjectiveRecombinant human platelet-derived growth factor (rhPDGF) is used topically in the treatment of diabetic lower-extremity ulcers. There have been few meta-analyses of the efficacy of rhPDGF in this treatment context. The aim of this study was to perform an updated systematic review and meta-analysis to assess the clinical efficacy of rhPDGF in the treatment of diabetic lower-extremity ulcers. MethodsWe searched the MEDLINE, Cochrane Library, EMBASE and Web of Knowledge databases up to April 30, 2014. Studies were identified and selected, and data were extracted by two independent reviewers. The primary efficacy outcome was complete healing rate. Adverse events were also assessed. The studies were evaluated for quality and publication bias. ResultsA total of 6 randomized controlled trials including 992 patients were selected from 173 identified studies. The studies compared rhPDGF treatment in the context of standard of care (SOC) to placebo or SOC alone. In the absence of study heterogeneity, a fixed-effects model was performed, and the combined odds ratio (OR) indicated a significantly greater complete healing rate in patients treated with rhPDGF compared to placebo or SOC alone. The ORs ranged from 0.58 to 2.77, with a combined OR of 1.53 (95% CI=1.14 to 2.04, p=0.004). A sensitivity analysis (leave-one-out method) indicated good study reliability, and a funnel plot with Egger test showed no publication bias. ConclusionThese results indicate that rhPDGF is efficacious in the treatment of diabetic lower-extremity ulcers.

Recombinant Human Platelet-Derived Growth Factor BB for Reconstruction of Human Large Extraction Site Defects

This study investigated the ability of growth factor-enhanced matrices combined with a tenting screw scaffolding system and resorbable membrane to regenerate large alveolar extraction site defects. Eight patients were randomized to treatment either with a bovine or equine matrix mixed in a ratio of 1.0 mL (0.3 mg/mL) recombinant human platelet-derived growth factor BB (rh-PDGF-BB) per gram of xenograft and allowed to absorb for 10 minutes. Tenting screws were used to provide additional support, and the growth factor-enhanced particulate matrix was incrementally placed and condensed into the defect and covered by a resorbable membrane. Reentry surgery after 5 months allowed for trephine core biopsies and implant placement. All sites healed well with evidence of bonelike hard tissue that was confirmed histologically as vital bone around the remaining graft particulate in both treatment groups. The results of this study demonstrate the capability of growth factor-enhanced matrices combined with tenting screws and a resorbable membrane to support the reconstruction of large extraction site defects.

Using Growth Factors in Human Extraction Sockets: A Histologic and Histomorphometric Evaluation of Short-Term Healing

Ridge preservation protocols reduce crestal remodeling after tooth extraction. There is insufficient evidence on bone grafting in combination with platelet-rich plasma (PRP) or recombinant human platelet-derived growth factor (rhPDGF-BB). The aim of this study is to evaluate healing of grafted and nongrafted sockets and the effect of PRP and rhPDGF-BB on early remodeling. Forty-one patients whose treatment plan included extraction of anterior or premolar teeth were randomized into four groups. Group 1: collagen plug (control). Group 2: mineralized freeze-dried bone allograft (FDBA)/β-tricalcium phosphate (β-TCP)/collagen plug. Group 3: FDBA/β-TCP/PRP/collagen plug. Group 4: FDBA/β-TCP/rhPDGF-BB/collagen plug. At 8 weeks, a core was harvested from the center of 41 sockets. Histomorphometric analysis took place. Differences were analyzed using one-way analysis of variance (ANOVA) or chi-square tests for continuous and categorical data. Pairwise comparisons were tested using least squares means. Spearman correlation coefficients were used to evaluate the relationship of bone growth with potential confounders. A P value < .05 was considered statistically significant. ANOVA did not indicate statistical significance in age, gender, smoking, ethnicity, or race distribution. Significant differences in tissue distribution were identified between groups and between different thirds of harvested core. More new bone and amorphous organic matrix was noted in the control group. In sites where bone graft was combined with growth factors, the amount of residual particles was less than in sites where bone graft was used alone. Inclusion of bone replacement graft suppressed new bone formation during early healing. Inclusion of PRP and rhPDGF-BB produced less residual bone graft material, indicating more rapid turnover of bone graft. All treatment modalities achieved a significant amount of new vital bone at 8 weeks postextraction.

A Comparative Evaluation of rhPDGF-BB + β-TCP and Subepithelial Connective Tissue Graft for the Treatment of Multiple Gingival Recession Defects in Humans

Today's patients are increasingly conscious of personal appearance, and much attention has been focused on denuded roots that are exposed during smiling. These concerns have given rise to numerous approaches for covering denuded root surfaces. Therefore, this study was undertaken to compare the effectiveness of recombinant human platelet-derived growth factor BB (rh-PDGF-BB) + β-tricalcium phosphate (β-TCP) and subepithelial connective tissue graft (SCTG) for the treatment of multiple gingival recession defects in humans. Thirty-six systemically healthy patients were randomly assigned to the PDGF, SCTG, and coronally positioned flap (CPF) groups. The PDGF and SCTG groups were treated with rhPDGF-BB + β-TCP and SCTG, respectively, while the CPF group was treated with a CPF alone. Clinical measurements including probing pocket depth (PPD), relative attachment level (RAL), and relative gingival margin level (RGML) were measured at baseline and at the 6-month follow-up. After 6 months, mean reduction in gingival recession in the PDGF and SCTG groups was 2.0 ± 0.6 mm and 2.6 ± 0.9 mm, respectively, whereas in the CPF group it was 1.7 ± 0.9 mm. The PDGF group showed mean root coverage of 87.7%, the SCTG group showed 91.3%, and the CPF group showed 68.6% at 6 months postsurgery. The combination of rhPDGF-BB and β-TCP represented a therapeutic combination that was effective in treating multiple gingival recession defects.

Reconstruction of the Narrow Ridge Using Combined Ridge Split and Guided Bone Regeneration with rhPDGF-BB Growth Factor–Enhanced Allograft

In clinical situations where the presence of severe horizontal ridge deficiencies precludes simultaneous implant placement and bone augmentation, a staged approach may be desirable to allow optimal implant placement. Numerous therapeutic options are available for the treatment of the horizontally deficient ridge. With advances in tissue engineering, the use of growth factors can significantly improve wound healing with more rapid bone formation and maturation. These case reports demonstrate a technique that enhances the predictability of horizontal bone gain with reduced surgical trauma and postoperative complications. Recombinant human platelet-derived growth factor BB (rhPDGF-BB) in combination with particulate allograft is used to stimulate the proliferation and migration of osteogenic cells. A ridge split technique with vertical bone incisions allows expansion and mobilization of the buccal plate, creating a space that will contain the particulate graft material. Decortication of the mobilized buccal plate will create pathways to allow cellular and vascular access for enhanced maturation. Additional graft material is placed lateral to the mobilized buccal plate to increase apical ridge width. The use of piezoelectric surgery enables a precise crestal bony incision in severely deficient ridge widths and aids in faster wound healing. This study discusses the technique and the recommended therapeutic considerations to ensure predictable regeneration of adequate bone for optimal implant placement in horizontally deficient ridges.

Vertical Ridge Augmentation of Atrophic Posterior Mandible Using Platelet-Derived Growth Factor: Two Case Reports

V ertical bone augmentation of the severely atrophic alveolar ridge remains a challenge in implant dentistry. Techniques such as onlay block graft, guided bone regeneration (GBR), distraction osteogenesis, and forced tooth eruption have been attempted by clinicians to achieve vertical bone gain on edentulous ridges. Nevertheless, some of these procedures are associated with unpredictable outcomes and undesirable complications. As an angiogenic, chemotactic, and mitogenic factor, recombinant human platelet-derived growth factor–BB (rhPDGF-BB) has recently been used in tissue engineering to regenerate osseous structures in various clinical settings. RhPDGF-BB has been demonstrated in human to facilitate bone growth with either cancellous allogenic block graft or a mixture of autogenous and xenogenic grafts for the reconstruction of localized ridge defects where the adjacent alveolar ridge has minimal vertical bone loss. For the posterior atrophic mandible, there is only 1 case report to date in human documenting the use of rhPDGF-BB with deproteinized bovine block for 3-dimensional ridge augmentation. In the current study, we outline a different approach to achieve bone augmentation on the edentulous alveolar ridge in human without the use of block grafts. The purpose of this report is to describe the combined use of rhPDGF-BB, titanium-reinforced expanded polytetrafluoroethylene (ePTFE) membrane, and particulate allogenic/xenogenic composite bone graft for vertical ridge augmentation on a severely atrophic posterior mandible in human.

Postextraction ridge preservation and augmentation with mineralized allograft with or without recombinant human platelet-derived growth factor BB (rhPDGF-BB): a consecutive case series.

In an attempt to reduce postextraction alveolar bone resorption, ridge preservation and augmentation procedures have become standard-of-care treatment following tooth removal. This consecutive case series compares histologic and histomorphometric bone regenerative findings at 4 months following grafting for ridge preservation and augmentation in intact sockets and sockets with buccal wall defects. Sites were treated with mineralized allograft alone (control) or in combination with 0.3 mg/mL recombinant human platelet-derived growth factor BB (rhPDGF-BB) (test). Sites were allowed to heal for 4 months and then re-entered for trephine core biopsy and implant placement. At the end of 4 months, the mean percent remaining mineralized allograft was statistically significantly less in the test group than in the control group. The difference in mean percent vital bone between the groups showed a strong trend toward greater bone formation for the test group (41.8%) compared to the control group (32.5%) at the end of 4 months. Addition of growth factor signaling molecules to current grafting procedures may lead to accelerated bone regeneration, making it possible to successfully place implants at earlier time points.

Growth Factor–Mediated Vertical Mandibular Ridge Augmentation: A Case Report

Posterior vertical alveolar ridge deficiencies are challenging defects to treat predictably and often require autogenous bone-harvesting procedures. Traditional treatment modalities, eg, guided bone regeneration, distraction osteogenesis, and autogenous grafts, present with a number of potential complications and limited success when used to restore vertical ridge height. Recent advances in recombinant growth factor technology may provide viable, alternative therapies for the treatment of significant alveolar ridge deficiencies. This proof-of-principle case report examines the utility and effectiveness of using a composite graft of freeze-dried bone allograft and recombinant human platelet-derived growth factor BB in conjunction with an overlying titanium mesh to regenerate well-vascularized bone in a significant posterior mandibular ridge defect prior to implant placement. The important role of the overlying periosteum as a possible key source of osteogenic cells during growth factor-enhanced regenerative procedures is emphasized.

High level expression, efficient purification and bioactivity assay of recombinant human platelet-derived growth factor AA dimer (PDGF-AA) from methylotrophic yeast Pichia pastoris

Platelet-derived growth factors (PDGFs) are important biochemical mediators regulating many physiological and pathophysiological processes, including promotion of the chemotactic recruitment and proliferation of cells involved in wound repair. Previously, homodimers of rhPDGF-AA protein were purified from Escherichia coli. However, eukaryotic proteins often contain posttranslational modifications, such as glycosylation, that are required for biological functions. In this study, an efficient method was established to purify a glycosylated rhPDGF-AA dimer from P. pastoris culture media by one step CM Sepharose ion exchange chromatography yielding about 20mg/L of over 95% highly purified rhPDGF-AA. Mass spectrometry analysis of the purified rhPDGF-AA displayed a molecular weight (MW) of 27,825.513Da, composed of a subunit with MW of 15,042.945Da and a subunit with MW of 12,904.374Da. The size difference is accounted for by differential glycosylation of the monomers. Biological activity of the rhPDGF-AA was confirmed by its ability to induce NIH/3T3 cells proliferation. The experimental procedure we have developed facilitates production of an active glycosylated rhPDGF-AA in large amounts for further research and drug development.

On a Quest to Dethrone the Long-Reigning King

Autograft is still regarded as the gold standard in bone-grafting, despite its well-appreciated limitations. The iliac crest has been the primary source of autologous bone, but other sites, such as the tibial metaphyses and the calcaneus, have also been commonly used. The techniques of autograft harvesting have recently evolved to include reamer-irrigator-aspirator (RIA) harvesting. RIA-harvested autograft can be used as stand-alone graft material or, for enhanced structural integrity, in combination with firmly packed cancellous graft. Both cancellous and RIA-harvested grafts have the distinction of being osteogenic, osteoinductive, and osteoconductive, all in their physiologic ratio. However, a need for additional surgical exposure, limited availability, and potential risks associated with graft harvesting have prompted a search for suitable autograft alternatives. The advent of recombinant human bone morphogenetic proteins (rhBMPs) generated optimism that the pursuit for an optimal alternative to autogenous bone graft had, at last, successfully ended. Bone morphogenetic proteins (BMPs) proved to be an extremely potent autograft substitute as evidenced by numerous preclinical and clinical studies. Although cleared by the U.S. Food and Drug Administration (FDA) for the highly selected orthopaedic indications, BMPs (rhBMP-2, rhBMP-7) have been extensively used off-label by many clinicians. However, the prevalent and serious adverse events associated with the on and off-label use of rhBMPs call for a revisiting of its clinical safety and efficacy1. The quest for an optimal bone graft alternative is, again, back on track. Recombinant human platelet-derived growth factor BB (rhPDGF-BB) has been introduced as another potent biologic graft substitute to stimulate cell proliferation, recruitment, and revascularization. Platelet-derived growth factor (PDGF) natively occurs as a dimeric polypeptide with A, B, C, or D chains, and …

A Novel Combined Surgical Approach to Vertical Alveolar Ridge Augmentation with Titanium Mesh, Resorbable Membrane, and rhPDGF-BB: A Retrospective Consecutive Case Series

The purpose of this case series was to report the clinical outcomes and histologic findings of vertical ridge augmentation using a combination of titanium mesh, resorbable collagen membrane, and recombinant human platelet-derived growth factor BB (rhPDGF-BB). Nineteen patients were included, and autogenous bone and anorganic bovine bone particles were used. The bone graft was mixed with rhPDGF-BB and loaded onto the bony defect up to the level of the adjacent alveolar crest. A pre-adapted titanium mesh was placed over the grafted region and covered with a resorbable collagen membrane, leaving no areas of the grafted region exposed. Seventeen patients exhibited good soft tissue healing. Postoperative flap dehiscence occurred relatively early in the healing period in one patient, whereas the covering collagen membrane was exposed during the later phase of the healing period in another. During reentry surgery for removal of the titanium mesh, three patients with favorable soft and hard tissue healing underwent bone biopsies for histologic evaluation of the augmented tissue just below the titanium mesh. The mean vertical height of augmented bone was 8.6 ± 4.0 mm. This report demonstrates the remarkable efficacy of guided bone regeneration using a combination of titanium mesh, resorbable collagen membrane, and rhPDGF for vertical ridge augmentation, thus expanding the indications for implant therapy and allowing recovery of the three-dimensional esthetic architecture in a severely absorbed alveolar ridge.

Horizontal Guided Bone Regeneration in the Posterior Maxilla Using Recombinant Human Platelet-Derived Growth Factor: A Case Report

This clinical case report describes and demonstrates the successful use of purified recombinant human platelet-derived growth factor in conjunction with autogenous bone, an organic bovine bone-derived mineral, and a barrier membrane to reconstruct severe alveolar bone defects. Significant horizontal bone regeneration was achieved in the posterior maxillary region. Three implants were placed into the newly formed ridge and demonstrated stable crestal bone after 36 months of loading.

A Histomorphometric Comparison of Bio-Oss Alone Versus Bio-Oss and Platelet-Derived Growth Factor for Sinus Augmentation: A Postsurgical Assessment

The purpose of this study was to assess vital bone formation at 4 to 5 months and 7 to 9 months following sinus augmentation with anorganic bovine bone matrix (ABBM) with and without recombinant human platelet-derived growth factor (rhPDGF). Twenty-four subjects received bilateral sinus elevation surgery with ABBM on one side and ABBM and rhPDGF on the contralateral side. Twelve patients had core sampling at 4 to 5 months and 12 patients at 7 to 9 months postoperatively. In subjects with cores taken at 4 to 5 months, mean vital bone, connective tissue, and residual graft were 11.8%, 54.1%, and 33.6%, respectively, with ABBM alone. Cores of sinuses filled with ABBM and rhPDGF showed mean 21.1% vital bone, 51.4% connective tissue, and 24.8% residual graft. Paired t test showed a statistically significant difference in vital bone. In cores taken at 7 to 9 months, the values for ABBM alone and ABBM + rhPDGF were 21.4% vs 19.5% vital bone, 28.4% vs 44.2% connective tissue, and 40.3% residual graft vs 35.5%. There was no statistically significant difference in vital bone at 7 to 9 months after surgery. Test and control groups showed clinically acceptable levels of vital bone both at 4 to 5 months and 7 to 9 months postsurgery. However, vital bone formation was significantly greater in the 4- to 5-month sections of ABBM + rhPDGF vs the Bio-Oss alone. In the 7- to 9-month specimens, this difference disappeared. More rapid formation of vital bone with the addition of rhPDGF may allow for earlier implant placement.

Platelet‐Derived Growth Factor Promotes Periodontal Regeneration in Localized Osseous Defects: 36‐Month Extension Results From a Randomized, Controlled, Double‐Masked Clinical Trial

Recombinant human platelet-derived growth factor (rhPDGF) is safe and effective for the treatment of periodontal defects in short-term studies up to 6 months in duration. We now provide results from a 36-month extension study of a multicenter, randomized, controlled clinical trial evaluating the effect and long-term stability of PDGF-BB treatment in patients with localized severe periodontal osseous defects. A total of 135 participants were enrolled from six clinical centers for an extension trial. Eighty-three individuals completed the study at 36 months and were included in the analysis. The study investigated the local application of β-tricalcium phosphate scaffold matrix with or without two different dose levels of PDGF (0.3 or 1.0 mg/mL PDGF-BB) in patients possessing one localized periodontal osseous defect. Composite analysis for clinical and radiographic evidence of treatment success was defined as percentage of cases with clinical attachment level (CAL) ≥2.7 mm and linear bone growth (LBG) ≥1.1 mm. The participants exceeding this composite outcome benchmark in the 0.3 mg/mL rhPDGF-BB group went from 62.2% at 12 months, 75.9% at 24 months, to 87.0% at 36 months compared with 39.5%, 48.3%, and 53.8%, respectively, in the scaffold control group at these same time points (P <0.05). Although there were no significant increases in CAL and LBG at 36 months among all groups, there were continued increases in CAL gain, LBG, and percentage bone fill over time, suggesting overall stability of the regenerative response. PDGF-BB in a synthetic scaffold matrix promotes long-term stable clinical and radiographic improvements as measured by composite outcomes for CAL gain and LBG for patients possessing localized periodontal defects ( ClinicalTrials.gov no. CT01530126).

Efficacy of Using PDGF and Xenograft With or Without Collagen Membrane for Bone Regeneration Around Immediate Implants With Induced Dehiscence‐Type Defects: A Microcomputed Tomographic Study in Dogs

Use of collagen membrane (CM) with xenograft and recombinant human platelet-derived growth factor (rhPDGF) in guided bone regeneration (GBR) is debatable. The aim of this microcomputed tomographic experiment was to assess the efficacy of using PDGF and xenograft (with or without CM) for GBR around immediate implants with dehiscence defects. Ten beagle dogs underwent atraumatic bilateral second and fourth premolar extractions from both arches. A standardized dehiscence defect (6 × 3 mm) was created on the buccal bone and immediate implants were placed in distal sockets in each site. Animals were randomly divided into three groups: 1) group 1, xenograft with rhPDGF was placed and covered with CM; 2) group 2, xenograft with rhPDGF was placed over the defects; and 3) group 3, four immediate implants were associated with dehiscence (controls). After 16 weeks, animals were sacrificed and jaw segments were assessed for buccal bone thickness (BBT), buccal bone volume (BBV), vertical bone height (VBH), and bone-to-implant contact (BIC) using microcomputed tomography. BBT was higher in group 2 (1.533 ± 0.89 mm) than group 1 (0.745 ± 0.322 mm) (P <0.001) and group 3 (0.257 ± 0.232 mm) (P <0.05). BBV was higher in group 2 (67.87 ± 19.83 mm(3)) than group 1 (42.47 ± 6.78 mm(3)) (P <0.05) and group 3 (19.12 ± 4.06 mm(3)) (P <0.001). VBH was higher in group 2 (6.36 ± 1.37 mm) than group 3 (0.00 ± 0.00 mm) (P <0.001). VBH was higher in group 1 (3.91 ± 2.68 mm) than group 3 (0.00 ± 0.00 mm) (P <0.05). BIC was higher in group 2 (67.25% ± 13.42%) than group 1 (36.25% ± 12.78%) (P <0.05) and group 3 (30.25% ± 7.27%) (P <0.01). GBR around immediate implants with dehiscence defects using PDGF and xenograft alone resulted in higher BBT, BBV, VBH, and BIC than when performed in combination with CM.

Effect of Implantation of Augment® Bone Graft on Serum Concentrations of Platelet-Derived Growth Factors: A Pharmacokinetic Study

Augment(®) Bone Graft is a bone graft substitute intended to be used as an alternative to autologous bone graft in the fusion of hindfoot and ankle joints. Augment(®) Bone Graft is a combination device comprised of beta-tricalcium phosphate (β-TCP) and recombinant human platelet-derived growth factor BB homodimer (rhPDGF-BB). This human pharmacokinetic study was undertaken to assess the effect of Augment(®) Bone Graft implantation on the serum concentration of platelet-derived growth factors (PDGFs). Under the terms of a Research Ethics Board-approved protocol, Augment(®) Bone Graft was implanted in patients (n = 7) undergoing hindfoot and ankle arthrodesis procedures requiring graft material. The control cohort of the study (n = 4) received autologous bone graft. The serum concentrations of PDGF isoforms AA, AB and BB in blood samples, obtained prior to and at ten time points (up to 7 days) after surgery, were measured using enzyme-linked immunosorbent assays (ELISA). The serum concentration of PDGF-BB did not vary significantly from baseline (median of the combined cohorts 3.89 ng/mL) throughout the course of the study. The serum concentrations of PDGF-AA, PDGF-AB and total PDGF did not deviate from their baseline values (medians of the combined cohorts were 2.87, 14.95 and 20.19 ng/mL for PDGF-AA, PDGF-AB and total PDGF, respectively) except for the last time point in which they were increased (medians for the combined cohorts were 4.71, 20.42 and 30.29 ng/mL for PDGF-AA, PDGF-AB and total PDGF, respectively). There were no differences between the two treatment groups with regard to changes in the serum concentrations of PDGF. None of the samples tested contained anti-PDGF-BB antibodies. Analysis of the data demonstrated that the serum concentrations of all three PDGF isoforms analysed were unaffected by implantation of Augment(®) Bone Graft.

Subepithelial Connective Tissue Graft with Growth Factor for the Treatment of Maxillary Gingival Recession Defect

Gingival recession is a challenging defect for clinicians to treat effectively. A number of recent systematic reviews have identified the connective tissue graft (CTG) in combination with coronally advanced flaps (CAFs) as the most consistently effective treatment for Miller Class I and II defects across all outcome measures. Recent advances in recombinant growth factor technology may provide opportunities for improved outcomes in conjunction with CAF + CTG procedures. In this prospective consecutive case series, recombinant human platelet-derived growth factor BB (rhPDGF-BB) was combined with CTGs for the treatment of Miller Class I or II gingival recession defects. Improved outcomes were seen for keratinized tissue gains and percent root coverage at 6 months postsurgery when compared to historic norms. All other outcome parameters appeared equivalent between the two treatment approaches. The addition of rhPDGF-BB appeared to improve early wound healing as well.

Stem cell therapy for critical limb ischemia: what can we learn from cell therapy for chronic wounds?

Although much progress has been made regarding our knowledge of stem cells and their potential applications for therapeutic angiogenesis, there has been less success with the clinical application of this knowledge to patients with critical limb ischemia (CLI). Patients with CLI often have chronic wounds and newer cell-based therapies for chronic wounds show interesting parallels to stem cell therapy for CLI. Several human-derived wound care products and therapies, including human neonatal fibroblast-derived dermis (Dermagraft®), bilayered bioengineered skin substitute (Apligraf®), recombinant human platelet-derived growth factor and autologous platelet-rich plasma may provide insight into the mechanisms through which differentiated cells can be used as therapy for chronic wounds, and, analogously, by which stem cells might function therapeutically in CLI.

Effect of recombinant human platelet-derived growth factor B on cat corneal endothelial cell viability mediated by adeno-associated virus.

To transduce recombinant human platelet-derived growth factor B(PDGF-B) gene adeno-associated virus(AAV) to in vitro cultured cat corneal endothelial cell (CEC) and observe the effect of the expressed PDGF-BB protein on the viability of cat CEC. Cat cornea endothelium was torn under microscope and rapidly cultivated in DMEM to form single layer CEC and the passage 2 endothelial cells were used in this study. The recombinant human PDGF-B gene AAV was constructed and transduced into cat CEC directly. Three groups were as following: blank control group, AAV control group and recombinant AAV group. At 24 hours, 48 hours, and 5 days after transduction, total RNA was extracted from the CEC by Trizol and the expression of PDGF-B gene was detected by fluorescence quantitative polymerase chain reaction. Viability of the transduced CEC was detected at 48 hours after transduction by MTT assay. Cell morphology was observed under inverted phase contrast microscope. With the torn endothelium culture technique, we rapidly got single layer cat CEC. At 24 hours, 48 hours and 5 days after transduction, fluorescence quantitative polymerase chain reaction showed there was no significant difference of the expressed PDGF-B gene mRNA between blank control group and AAV control group (P>0.05). In contrast, there were significant differences between two control groups and recombinant AAV group (P<0.05). MTT assay showed that in recombinant AAV group, the expressed PDGF-BB protein could promote the viability of cat CEC. Morphology observation showed at 48 hours after transduction, cells in CEC-AAV-PDGF-B group proliferated into bigger scales in regular triangle to hexagon shape with distinct boundary, while the number of cells was significantly less in the two control groups. The recombinant AAV-PDGF-B expresses biological active PDGF-BB protein in cat CECs, which promotes the viability and proliferation of cells.

A Comparative Study of Root Defect Coverage Using an Acellular Dermal Matrix With and Without a Recombinant Human Platelet‐Derived Growth Factor

The objective of this case series is to compare root defect coverage results and healing responses of bilateral recession defects treated with acellular dermal matrix (ADM) with and without recombinant human platelet-derived growth factor (rhPDGF). Seventeen patients with 40 bilateral gingival recession defects were compared. Each defect was ≥2 mm and treated with ADM and a coronally advanced flap. Using split-mouth design, the control-side ADM was hydrated in sterile saline, whereas the test-side ADM was hydrated in rhPDGF. The patients were evaluated at 1 week, 1 month, 3 months, and 6 months. Standardized measurements were taken preoperatively at 3 and 6 months. Healing was clinically assessed at 1 week and 1 month post-surgically. Both test and control groups showed significant gain in root defect coverage over the 6-month period for all individuals, with the test group showing a 69.0% gain and the control group showing a 76.7% gain. Patients divided into Miller Class I and Class III defects were also found to have a significant gain in root defect coverage over 6 months. The test group showed 84.1% gain, and the control group showed 84.7% gain for Miller Class I defects. For Miller Class III defects, the test group showed 51.5% gain, and the control group showed a 60.8% gain. One week after surgery, 35% of the test group showed better healing, whereas 15% of the control group showed better healing. One month after surgery, 20% of the test group showed better healing, whereas 15% of the control group showed better healing. Based on the results of this case series, there were no statistically or clinically significant differences in root defect coverage, keratinized tissue, clinical attachment level, or clinical healing for treatment of root recession with a coronally advanced flap and ADM with and without rhPDGF.