Concentrated growth factor promotes Schwann cell migration partly through the integrin β1-mediated activation of the focal adhesion kinase pathway

A randomized controlled clinical trial of concentrated growth factor combined with sodium hyaluronate in the treatment of temporomandibular joint osteoarthritis

OBJECTIVE

To investigate the effect of concentrated growth factor (CGF) combined with sodium hyaluronate (SH) on temporomandibular joint osteoarthritis (TMJOA).

METHODS

Sixty patients with TMJOA who were diagnosed by cone-beam computed tomography (CBCT) between March 2020 and March 2023 at the Stomatological Hospital of Xi'an Jiaotong University were randomly divided into a control group (n = 30) and an experimental group (n = 30). The patients in the experimental group were treated with CGF + SH, and those in the control group were treated with SH only. The visual analogue scale (VAS) score indicating pain in the temporomandibular joint (TMJ) area; the Helkimo Clinical Dysfunction Index (Di); and changes in condylar CBCT at the first visit and 2 weeks, 3 months and 6 months after treatment were recorded. The CBCT data of the patients in the experimental and control groups were collected, and the three-dimensional CBCT image sequences were imported into Mimics Medical 19.0 software in DICOM format for condylar reconstruction.

RESULTS

The VAS scores at 2 weeks, 3 months and 6 months after treatment were significantly lower in the experimental group than in the control group (P < 0.05), and the pain in the experimental group was significantly relieved. The Di was significantly lower in the experimental group than in the control group (P < 0.05), and the clinical function of the TMJ improved. After treatment, the CBCT score was significantly lower in the experimental group than in the control group (P < 0.05), and the condylar bone cortex was obviously repaired. Observation of the condylar bone cortex by three-dimensional reconstruction showed the same results as those obtained by CBCT.

CONCLUSION

CGF combined with SH is effective in the treatment of TMJOA and can improve muscle pain, TMJ pain, Impaired TMJ function, Impaired range of movement, Pain on movement of the mandible and promote bone repair.

THE REGISTRATION NUMBER (TRN)

ChiCTR2400082712.

THE DATE OF REGISTRATION

April 5, 2024.

Can concentrated growth factor prevent postoperative complications of impacted third molar surgery? A split-mouth randomized double-blind trial

OBJECTIVES

The purpose of the present study was to evaluate the effect of concentrated growth factor (CGF) on prevention of postoperative complications in the impacted third molar extraction.

MATERIALS AND METHODS

A total of 25 healthy patients with symmetrical bilaterally impacted third molars (50 extraction sites) were enrolled in this split-mouth, randomized, double-blind clinical trial. Third molar extractions were performed in both sites of the mandible at the same appointment. Randomization was performed using a coin toss to choose the test and control sites. CGF was placed in the extraction socket and the socket was sutured (test group), while the contralateral socket was only sutured (control group). Each patient acted as their own control. The primary outcome were pain assessed by visual analog scale (VAS) and facial swelling on the1st, 3rd and 7th postoperative days. The secondary outcomes were bone healing in extraction sockets through alveolar bone height (ABH) and alveolar bone density (ABD) evaluated by cone beam computed tomography (CBCT) immediately after extraction and in the 3rd and 6th months.

RESULTS

Twenty-five patients (12 female, 13 male; mean age 29.17) with bilateral impacted third molars participated in the study. A statistically significant reduction in pain was determined on the 3rd and 7th postoperative days in the CGF sites compared to the control sites while no statistically significant difference was found between the groups on the 1st postoperative day (3rd day, p = 0.009; 7th day, p = 0.039). There were no statistically significant differences in facial swelling and bone healing between the test and control groups at different time intervals, although the data obtained were slightly favoring the CGF group (p > 0.05). There were no serious adverse effects such as infection, alveolitis, paraesthesia, fracture through the follow-up period in all of the cases.

CONCLUSION

The study has demonstrated the effect of CGF on relieving the severity of pain after the third molar extraction.

CLINICAL RELEVANCE

Placement of CGF in the extraction socket could relieve postoperative pain and reduce patient discomfort after the third molar extraction. CGF is recommended during the third molar extraction due to its good biological effects, low cost and simple preparation procedures.

TRIAL REGISTRATION NUMBER

ChiCTR2300077819.

Dexamethasone and concentrated growth factors on peripheral nerve injury: A clinic-relevant animal study

BACKGROUND

Mandibular nerve injury is a common clinical condition that affects clinicians' management and patients' quality of life. In the literature, there are various effective treatments available. The primary purpose of this study was to determine and compare the effects of dexamethasone and concentrated growth factor (CGF) on regeneration in patients with nerve trauma that mimics clinical situations.

METHODS

In this study, 36 rats were divided into 3 groups: the control, dexamethasone and CGF groups. The inferior alveolar nerve was traumatized through the extraction socket after mandibular molar tooth extraction in each group.

RESULTS

The data showed a decrease in the control (4.5-4), dexamethasone (3-2), and CGF (4-3) groups according to the histological injury severity score (HISS) results. Compared with those in the other groups, the number of degenerative axons and edematous areas observed via histological examination were significantly lower in the CGF groups. Similarly, compared with those in the control group, the nNOS and Neurofilament-H positivity in the dexamethasone group on the 30th day (2,2 to 1,1 respectively) was significantly lower. The positivity of all the primary antibodies in the 3rd and 30th day CGF groups was significant compared than that in the dexamethasone 30th day group.

CONCLUSION

According to the results of the analysis of the immunohistopathological and HISS data, the CGF groups exhibited greater regeneration than did the dexamethasone groups.

Use of Concentrated Growth Factor (CGF) in Prosthetic-Guided Reconstruction on Two-Wall Bone Defect after Cystectomy: An Alternative to Traditional Regeneration

This clinical case report's objective was to describe an alternative technique executed to ensure bone regeneration after removing a cystic lesion in the upper jaw. The bone defect after the cystectomy was filled with autologous fibrin-rich clots containing concentrated growth factor (CGF). A 45-year-old female patient was presumed to have a cystic lesion with massive bone destruction on the vestibular and palatal walls between teeth 2.2 and 2.3. CGF was applied to fill the gap to promote the development of the bone. The tooth was asymptomatic and repair was still increasing steadily after a year, according to the results of the clinical and radiological follow-up assessment. This article describes a different way to treat a two-wall defect involving both the palatal and buccal bone, after removing a cystic lesion, with the use of CGF as an equivalent to the traditional use of autologous or heterologous bone. A promising substance for bone repair is CGF fibrin, which may encourage the growth of new bone in jaw deformities and promote bone tissue healing.

BDNF and Krox20 as Indicators of Platelet-rich Plasma-Induced Nerve Regeneration in a Neuropathic Orofacial Pain Model

OBJECTIVE

 Various growth factors contained in PRP can increase angiogenesis and cell proliferation, which plays an essential role in the process of neuroregeneration and peripheral nerve injury recovery. This study analyzed PRP effects in the neuro-regeneration of axonotmesis through brain-derived neurotrophic factor (BDNF) and Krox20 expressions.

MATERIALS AND METHODS

 Freeze-dried allogeneic platelet-rich plasma (PRP) were prepared from allogeneic sources. Forty-two Rattus norvegicus were divided into three groups: negative control group, positive control group (crushing infraorbital nerve) and treatment group (crushing infraorbital nerve without PRP injection). Each group was observed for fourteen and twenty-one days after injury. Infraorbital nerve tissue is isolated for indirect immunohistochemistry examination with BDNF and Krox20 antibodies. Data analysis was performed using One-Way ANOVA and Mann-Whitney tests with significant value as p < 0.05.

RESULTS

 The PRP group showed BDNF expression significantly higher than control positive groups, both observation days (p = 0.00). A higher Korx20 expression showed by the PRP group after 21 days than in the control positive groups (p = 0.002).

CONCLUSION

 PRP can potentially improve neuroregeneration of axonotmesis through increased BDNF and Krox20 expression on the twenty-one days after injury.

The therapeutic effect of concentrated growth factor gel on skin wounds with bone or tendon exposure

Treatment of soft tissue wounds with bone or tendon exposure remains a tough clinical challenge for surgeons. The current clinical approaches include various types of flap reconstruction and artificial dermis grafting as well as negative pressure wound therapy (NPWT), which are time-consuming and often result in graft failure or significant scarring. Concentrated growth factor (CGF) is a novel blood extract that contains many growth factors, platelets and fibrin to promote an orderly healing process. However, few reports have focused on wounds with bone or tendon exposure. We present a limited series and two specific cases of skin wound with bone or tendon exposed that received surgical debridement followed by CGF treatment. CGF appeared to facilitate wound closure effectively and also reduced scar formation. Our findings provide a novel therapeutic option for refractory wounds with bone or tendon exposure.

Effectiveness of concentrated growth factor and laser therapy on wound healing, inferior alveolar nerve injury and periodontal bone defects post-mandibular impacted wisdom tooth extraction: A randomized clinical trial

The extraction of wisdom teeth with mandibular impact frequently results in complications including damage to the inferior alveolar nerve (IAN) and malformations of the bone. The objective of this research endeavour was to assess the efficacy of low-level laser therapy and concentrated growth factor (CGF) in facilitating nerve recovery and wound healing in such instances. A total of thirty-one patients (mean age 27.52 ± 5.79 years) who presented with IAN injury after extraction were randomly assigned to one of three groups: control group (which received oral mecobalamin), CGF group (which received CGF gel applied to the extraction sockets) and laser group (which received low-level lasers (808 nm, 30 mW, 10 J/cm2 )) at the extraction site. Patients' recovery from IAN paresthesia was evaluated seven times over the course of 14 days utilizing visual analogue scale (VAS) and the pinprick test (PP). At multiple intervals following surgery, periodontal probing and bone level measurements were utilized to assess the recovery of both soft and hard tissues. The findings revealed that, compared with the control group, both the CGF and laser treatment groups exhibited a markedly greater improvement in VAS scores and wound healing of soft tissues, as well as in PP results (p < 0.001), indicating enhanced wound healing processes. Despite these improvements, there was no significant difference in wound healing outcomes between the CGF and laser groups. Notably, the CGF group showed a statistically significant improvement in healing bone defects at 30 and 90 days post-treatment compared with the control group (p = 0.003 and p = 0.004, respectively), underscoring its effectiveness in bone healing as a critical aspect of the overall wound healing process. However, in terms of other wound healing comparisons, no significant differences were observed. CGF and laser therapy significantly enhanced the healing of wounds, including soft tissue and bone recovery, in addition to accelerating the recovery of IAN injuries following mandibular wisdom tooth extraction. Although both treatments were equally effective in nerve recovery, CGF notably excelled in promoting bone healing, suggesting its pivotal role in comprehensive wound healing. This highlights that both CGF and laser therapy are viable options for not only nerve recovery but also for overall wound healing in such dental procedures.

Concentrated Growth Factor (CGF): The Newest Platelet Concentrate and Its Application in Nasal Hyaluronic Acid Injection Complications

BACKGROUND

Several cases of wounds caused by vascular compromise after facial cosmetic injection have been reported in recent years. How to promote wound healing, restore facial appearance, and avoid secondary injury in such patients have remained a clinical challenge. Our study was designed to assess the effect of concentrated growth factor (CGF) for repairing nasal wounds after nasal hyaluronic acid injection.

METHODS

Six women with nasal wounds after hyaluronic acid injection were enrolled from June 2019 to June 2022. The average time of the first CGF treatment from admission was 2-4 days. CGF gel was prepared from each patient's blood by using a Medifuge™ system. After debridement of the wound, the prepared CGF gel was applied on the wound surface, and the wound dressing was fixed to stabilize the CGF gel. The CGF treatment interval was 3-4 days.

RESULTS

The wound began to heal after the first CGF treatment. After 2-3 CGF treatments, the wound was almost completely healed. There was no deflection of the nasal columella, and nasal ventilation function was good. There was no obvious deformity in the appearance of the nose. After follow-up ranging from 2 months to 1 year, the appearance and function of the nose showed satisfactory recovery.

CONCLUSIONS

CGF has great potential in promoting wound healing and restoring the appearance after complications from nasal hyaluronic acid injection. The preparation of CGF gel is simple, and the clinical application is convenient and safe. In future, more clinical trials are needed to further prove the efficacy and safety of CGF in the treatment of wounds secondary to cosmetic injection.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors http://www.springer.com/00266 .

Clinical Effect Evaluation of Concentrated Growth Factor in Endodontic Microsurgery: A Cross-Sectional Study

INTRODUCTION

Concentrated growth factor (CGF) is the third-generation platelet concentrate product. This study aimed to evaluate whether the use of CGF during endodontic microsurgery had a positive influence on surgical outcomes.

METHODS

Fifty-four patients who underwent endodontic microsurgery from January 2017 to November 2021 were enrolled. They were assigned to the CGF and the control group according to whether CGF was used during the surgery and followed up at 6, 12, and 18 months post-surgery. Preoperative classification of the cases and follow-up radiographic outcomes were based on Kim's classification and Molven's criteria respectively and evaluated by two calibrated endodontists. Student t-test and Chi-square test were used to assess the baseline of two groups. Rank sum test was used to determine whether CGF had an impact on the surgical outcome.

RESULTS

Thirty-one patients (41 periapical lesion sites) were included in the CGF group, and twenty-three patients (26 periapical lesion sites) were included in the control group. The overall success rate of endodontic microsurgery was above 90%. The baseline of the two groups had no difference (P<0.05). In the CGF group, the success rate was always 100% in three follow-ups, while the success rate was 84.2%, 92.8%, and 90% respectively in the control group. The success rate between the CGF group and the control group was statistically significant in all three follow-up points (P<0.05).

CONCLUSIONS

The application of CGF during endodontic microsurgery might have a positive influence on surgical outcomes, thus, its prognosis. However, higher-grade evidence is needed to demonstrate its role.

Platelet-rich plasma promotes peripheral nerve regeneration after sciatic nerve injury

The effect of platelet-rich plasma on nerve regeneration remains controversial. In this study, we established a rabbit model of sciatic nerve small-gap defects with preserved epineurium and then filled the gaps with platelet-rich plasma. Twenty-eight rabbits were divided into the following groups (7 rabbits/group): model, low-concentration PRP (2.5–3.5-fold concentration of whole blood platelets), medium-concentration PRP (4.5–6.5-fold concentration of whole blood platelets), and high-concentration PRP (7.5–8.5-fold concentration of whole blood platelets). Electrophysiological and histomorphometrical assessments and proteomics analysis were used to evaluate regeneration of the sciatic nerve. Our results showed that platelet-rich plasma containing 4.5–6.5- and 7.5–8.5-fold concentrations of whole blood platelets promoted repair of sciatic nerve injury. Proteomics analysis was performed to investigate the possible mechanism by which platelet-rich plasma promoted nerve regeneration. Proteomics analysis showed that after sciatic nerve injury, platelet-rich plasma increased the expression of integrin subunit β-8 (ITGB8), which participates in angiogenesis, and differentially expressed proteins were mainly enriched in focal adhesion pathways. Additionally, two key proteins, ribosomal protein S27a (RSP27a) and ubiquilin 1 (UBQLN1), which were selected after protein-protein interaction analysis, are involved in the regulation of ubiquitin levels in vivo. These data suggest that platelet-rich plasma promotes peripheral nerve regeneration after sciatic nerve injury by affecting angiogenesis and intracellular ubiquitin levels.

Platelet-rich plasma loaded nerve guidance conduit as implantable biocompatible materials for recurrent laryngeal nerve regeneration

Vocal cord paralysis caused by recurrent laryngeal nerve (RLN) injury during thyroidectomy results in hoarseness, aspiration, and dyspnea. We evaluated the usefulness of nerve guidance conduits (NGCs) constructed from an asymmetric polycaprolactone (PCL)/Pluronic F127 porous membrane and filled with platelet-rich plasma (PRP) for functional RLN regeneration. We evaluated the proliferation and migration of Schwann cells (SCs) after PRP treatment in vitro. For the in vivo study, rabbits were divided into a non-loaded NGC group and a PRP-loaded NGC group. The left RLNs were resected and interposed with the NGCs. Functional and histological examinations of the vocal cords were performed. SC proliferation and migration increased in a PRP dose-dependent manner, with the PRP increasing the levels of neurotrophic factors, myelin-associated glycoprotein, and ERK. In vivo, the PRP group showed significantly better vocal cord mobility and less vocalis muscle atrophy than the non-loaded NGC group. Histologically, the ingrowth of nerve endings occurred more rapidly in the PRP group, and acetylcholinesterase, neurofilament, and S-100 expression in neural endings were significantly higher in the PRP group. Furthermore, transmission electron microscopy showed that myelinated axons were more tightly packed in the PRP group. This study shows that PRP-loaded NGCs provide a favorable environment for neural regeneration and suggests that this technique has therapeutic potential for promoting RLN recovery.

Effect of concentrated growth factor (CGF) on postoperative sequel of completely impacted lower third molar extraction: a randomized controlled clinical study

BACKGROUND

The surgical extraction of impacted third molars is one of the most common procedures in oral and maxillofacial surgery, which associated with several postoperative complications. The aim of this clinical trial was to estimate the implication of concentrated growth factor (CGF) on postoperative sequelae after the completely impacted lower third molar extraction.

MATERIALS AND METHODS

A total of 74 sides of 37 participants who had completely bilateral impacted lower third molars were enrolled in this split-mouth, randomized single‑blind, clinical trial. Surgical extraction was undertaken on both sides of the mandible. Randomization was achieved by opaque, sealed envelopes. The postoperative outcomes including wound healing, swelling and pain were clinically assessed at different-time intervals(1st, 3rd and 7th days). A p-value < 0.05 was considered statistically significant.

RESULTS

The wound healing index was significantly better in the test sides (P = 0.001). Regarding the facial swelling, the test sides had significantly less values than the control sides, particularly on the 1st (1.01 ± .57 vs. 1.55 ± .56) and 3rd days (1.42 ± 0.8 vs. 2.63 ± 1.2) postoperatively. Nonetheless, the swelling was disappeared within the 7th day in both sides. The pain scores of visual analog scale were no a statistically significant difference between both sides on the 1st day, meanwhile, the pain scores were significantly lower in the test sides compared with the control sides, especially on the 3rd (P = 0.001) and 7th days (P < 0.001) postoperatively.

CONCLUSION

The application of CGF following the surgical extraction of lower third molar has accelerated the healing of soft tissues as well as reduced postoperative sequelae such as swelling and pain. Therefore, the CGF could be promoted among clinicians during the lower third molar surgical extraction.

TRIAL REGISTRATION

This study was registered with the TCTR identification number TCTR20210325002 on 25/03/2021 at Thai Clinical Trials Register-Medical Research Foundation of Thailand (MRF). Also it was ethically approved from the institutional ethics committee at the Hospital of Stomatology, Xian Jiaotong University, Xian, China (No: 032), and has been conducted in accordance to the guidelines of the declaration of Helsinki. Written informed consent was obtained from all participants in the study.

Evaluation of Platelet-Rich Plasma Therapy for Peripheral Nerve Regeneration: A Critical Review of Literature

Peripheral nerve injury (PNI) is a common disease in clinic, and the regeneration process of peripheral nerve tissue is slow, and patients with PNI often suffer from the loss of nerve function. At present, related research on the mechanism of peripheral nerve regeneration has become a hot spot, and scholars are also seeking a method that can accelerate the regeneration of peripheral nerve. Platelet-rich plasma (PRP) is a platelet concentrate extracted from autologous blood by centrifugation, which is a kind of bioactive substance. High concentration of platelets can release a variety of growth factors after activation, and can promote the proliferation and differentiation of tissue cells, which can accelerate the process of tissue regeneration. The application of PRP comes from the body, there is no immune rejection reaction, it can promote tissue regeneration with less cost, it is,therefore, widely used in various clinical fields. At present, there are relatively few studies on the application of PRP to peripheral nerve regeneration. This article summarizes the literature in recent years to illustrate the effect of PRP on peripheral nerve regeneration from mechanism to clinical application, and prospects for the application of PRP to peripheral nerve.

Effect of concentrated growth factor on lower lip hypoesthesia after osseous genioplasty: a prospective, split-mouth, double-blind randomized controlled trial

Lower lip hypoesthesia is the most common complication following osseous genioplasty. Concentrated growth factor (CGF) has recently been shown to improve neural regeneration. The aim of this study was to evaluate the effect of concentrated growth factor on neurosensory recovery after osseous genioplasty. Patients who underwent osseous genioplasty between June 2017 and February 2020 were enrolled. CGF was applied to the mental nerve on one side. The treatment side was randomized, and the other side was considered as the control. Lower lip hypoesthesia was assessed preoperatively and postoperatively (1 week, 1, 3, 6, and 9 months) using the two-point discrimination test and a 10-point visual analogue scale (self-reported paresthesia). The assessor was blinded. Twenty-six female patients completed the study. At 1 and 3 months, both the mean two-point discrimination value and mean visual analogue scale score were significantly lower in the CGF group than in the control group (P < 0.001). At 3 months, the percentage of patients with lower lip hypoesthesia in the CGF group was significantly lower than that in the control group (P < 0.001). Both groups showed resolution of lower lip hypoesthesia at 6 months. Concentrated growth factor may accelerate the recovery of long-standing sensory nerve impairment following mental osteotomy.

Effects of platelet concentrates on implant stability and marginal bone loss: a systematic review and meta-analysis

Background

Osseointegration is essential for the success and stability of implants. Platelet concentrates were reported to enhance osseointegration and improve implant stability. The purpose of this review is to systematically analyze the effects of platelet concentrates on implant stability and marginal bone loss.

Methods

Two researchers independently performed searches in the following databases (last searched on 21 July 2021): MEDLINE (PubMed), Cochrane Library, EMBASE, and Web of Science. In addition, a manual search was carried out on references of relevant reviews and initially included studies. All randomized controlled trials (RCTs) and controlled clinical trials (CCTs) on the application of platelet concentrates in the implant surgery procedure were included. The risk of bias of RCTs and CCTs were assessed with a revised Cochrane risk of bias tool for randomized trials (RoB 2.0) and the risk of bias in non-randomized studies—of interventions (ROBINS-I) tool, respectively. Meta-analyses on implant stability and marginal bone loss were conducted. Researchers used mean difference or standardized mean difference as the effect size and calculated the 95% confidence interval. In addition, subgroup analysis was performed based on the following factors: type of platelet concentrates, method of application, and study design.

Results

Fourteen studies with 284 participants and 588 implants were included in the final analysis. 11 studies reported implant stability and 5 studies reported marginal bone level or marginal bone loss. 3 studies had high risk of bias. The meta-analysis results showed that platelet concentrates can significantly increase implant stability at 1 week (6 studies, 302 implants, MD 4.26, 95% CI 2.03–6.49, P < 0.001) and 4 weeks (8 studies, 373 implants, MD 0.67, 95% CI 0.46–0.88, P < 0.001) after insertion, significantly reduced marginal bone loss at 3 months after insertion (4 studies, 95 implants, mesial: MD − 0.33, 95% CI − 0.46 to − 0.20, P < 0.001; distal: MD − 0.38, 95% CI − 0.54 to − 0.22, P < 0.001). However, the improvement of implant stability at 12 weeks after insertion was limited (P = 0.10). Subgroup analysis showed that PRP did not significantly improve implant stability at 1 week and 4 weeks after insertion (P = 0.38, P = 0.17). Platelet concentrates only placed in the implant sites did not significantly improve implant stability at 1 week after insertion (P = 0.20).

Conclusions

Platelet concentrates can significantly improve implant stability and reduce marginal bone loss in the short term. Large-scale studies with long follow‐up periods are required to explore their long-term effects and compare effects of different types.

Trial registration

This study was registered on PROSPERO, with the Registration Number being CRD42021270214.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-021-01929-x.

Application of concentrated growth factor to autotransplantation with inflammation in recipient area

OBJECTIVE

The purpose of this study was to apply concentrated growth factor (CGF) to the transplanted area with inflammation, to observe the clinical effects of CGF on the inflammation area assisted by 3D printing technology.

METHODS

A total of 52 compromised mandibular first or second molar with chronic periapical lesions were transplanted with mature third molars. The patients were divided into CGF group (n = 26) and control group (n = 26) and transplanted into fresh extraction sockets with or without CGF. All the patients underwent clinical and radiographic examinations during the follow-up.

RESULTS

Average surgery and extra-oral time were 39 min (± 7.8) and 42 s (± 10.2). The success rates of CGF group and control group were 100% and 92.3% respectively. Most of the periapical lesions in CGF group healed completely within 3 months, which was significantly faster than control group. The initial stability of CGF group was better than control group immediately after operation, and the degree of pain in CGF group was lower than control group on the 1st and 3rd day after operation.

CONCLUSIONS

The application of CGF in recipient site with chronic periapical lesions can accelerate the regeneration of alveolar bone and the healing of inflammation, greatly shorten the healing period. Meanwhile, CGF help to reduce postoperative pain and reaction at the early stage of healing and increase the success rate of autogenous tooth transplantation (ATT). Additionally, the use of 3D printing model can greatly reduce the extra-oral time of donor teeth.

Analysis of CGF Biomolecules, Structure and Cell Population: Characterization of the Stemness Features of CGF Cells and Osteogenic Potential

Concentrated Growth Factors (CGF) represent new autologous (blood-derived biomaterial), attracting growing interest in the field of regenerative medicine. In this study, the chemical, structural, and biological characterization of CGF was carried out. CGF molecular characterization was performed by GC/MS to quantify small metabolites and by ELISA to measure growth factors and matrix metalloproteinases (MMPs) release; structural CGF characterization was carried out by SEM analysis and immunohistochemistry; CGF has been cultured, and its primary cells were isolated for the identification of their surface markers by flow cytometry, Western blot, and real-time PCR; finally, the osteogenic differentiation of CGF primary cells was evaluated through matrix mineralization by alizarin red staining and through mRNA quantification of osteogenic differentiation markers by real-time PCR. We found that CGF has a complex inner structure capable of influencing the release of growth factors, metabolites, and cells. These cells, which could regulate the production and release of the CGF growth factors, show stem features and are able to differentiate into osteoblasts producing a mineralized matrix. These data, taken together, highlight interesting new perspectives for the use of CGF in regenerative medicine.

Angiogenic Properties of Concentrated Growth Factors (CGFs): The Role of Soluble Factors and Cellular Components

Blood-derived concentrated growth factors (CGFs) represent a novel autologous biomaterial with promising applications in regenerative medicine. Angiogenesis is a key factor in tissue regeneration, but the role played by CGFs in vessel formation is not clear. The purpose of this study was to characterize the angiogenic properties of CGFs by evaluating the effects of its soluble factors and cellular components on the neovascularization in an in vitro model of angiogenesis. CGF clots were cultured for 14 days in cell culture medium; after that, CGF-conditioned medium (CGF-CM) was collected, and soluble factors and cellular components were separated and characterized. CGF-soluble factors, such as growth factors (VEGF and TGF-β1) and matrix metalloproteinases (MMP-2 and -9), were assessed by ELISA. Angiogenic properties of CGF-soluble factors were analyzed by stimulating human cultured endothelial cells with increasing concentrations (1%, 5%, 10%, or 20%) of CGF-CM, and their effect on cell migration and tubule-like formation was assessed by wound healing and Matrigel assay, respectively. The expression of endothelial angiogenic mediators was determined using qRT-PCR and ELISA assays. CGF-derived cells were characterized by immunostaining, qRT-PCR and Matrigel assay. We found that CGF-CM, consisting of essential pro-angiogenic factors, such as VEGF, TGF-β1, MMP-9, and MMP-2, promoted endothelial cell migration; tubule structure formation; and endothelial expression of multiple angiogenic mediators, including growth factors, chemokines, and metalloproteinases. Moreover, we discovered that CGF-derived cells exhibited features such as endothelial progenitor cells, since they expressed the CD34 stem cell marker and endothelial markers and participated in the neo-angiogenic process. In conclusion, our results suggest that CGFs are able to promote endothelial angiogenesis through their soluble and cellular components and that CGFs can be used as a biomaterial for therapeutic vasculogenesis in the field of tissue regeneration.

The effect of concentrated growth factor (CGF) in the surgical treatment of medication-related osteonecrosis of the jaw (MRONJ) in osteoporosis patients: a randomized controlled study

OBJECTIVES

The purpose of this present study was to evaluate the efficiency of the growth factors delivered by concentrated growth factor (CGF) on the healing process of osteoporotic patients with medication-related osteonecrosis of the jaws (MRONJ).

METHODS

This randomized controlled study was composed of osteoporotic female patients who were treated with oral bisphosphonates (BPs) and diagnosed with MRONJ. For the CGF group, each patient was treated with a local application of CGF at the surgical site after removing the necrotic bone, while the surgical area was primarily closed as traditional surgical therapy for the control group. The patients underwent clinical examinations for 6 months postoperatively to check the presence of infection and dehiscence.

RESULTS

Complete healing was achieved in 19 patients of 28 patients (mean age: CGF group, 73.57 ± 5.1; control group, 73.64 ± 5.49) diagnosed with MRONJ. There was no significant difference in post-op healing data between groups during healing periods (p > 0.05). In the CGF group (n = 14) in three cases, bone exposure without infection was detected, and one of them showed a recurrent infection. In the control group (n = 14) in six cases, bone exposure without infection was detected, and three of them also showed recurrent infection.

CONCLUSION

Although our results were not statistically significant, our findings suggest that the local application of CGF appears to be an effective approach to the surgical treatment of MRONJ in osteoporosis patients by improving tissue regeneration.

CLINICAL RELEVANCE

A specific treatment protocol to manage MRONJ is still controversial. This study justifies that CGF can be used in combination with surgical treatment.

Effect of concentrated growth factors on frequency of alveolar Osteitis following partially-erupted mandibular third molar surgery: a randomized controlled clinical study

Background

The aim of this prospective study was to assess the effectiveness of concentrated growth factors (CGF) in preventing the development of alveolar osteitis (AO) after the extraction of partially-erupted mandibular third molars.

Methods

Seventy patients (26 men and 44 women) 18 years or older (mean age 25.86; range 18–35) underwent 140 third molar extractions. All the patients presented with bilateral, partially-erupted mandibular third molars and underwent surgical extractions. In each case, one socket received CGF and the other served as a control. The predictor variable was the CGF application and the sides were categorized as ‘CGF’ and ‘non-CGF’. The outcome variable was the development of AO during the first postoperative week. Other study variables included age and gender. Data were analyzed using Cochran’s Q test with the significance level set at a P value less than 0.05.

Results

The overall frequency of AO was 11.4% for the control group. The frequency of AO in the CGF group was significantly lower than in the non-CGF group (p < 0.001).

Conclusions

Based on the results of this study, application of CGF fibrin gel may decrease the risk of AO development after mandibular third molar surgery.

Trial registration

This study was registered in ClinicalTrials.gov database on November 1, 2019 (ID: NCT04151147, retrospectively registered).

A Comprehensive Review of Concentrated Growth Factors and Their Novel Applications in Facial Reconstructive and Regenerative Medicine

BACKGROUND

Concentrated growth factors (CGFs) are the latest generation of platelet concentrates. The objective of developing CGF is to increase therapeutic efficacy. However, few studies have supported the superiority of CGF in composition and efficacy. The reconstruction and regeneration process is complicated and long term, whereas bioactivity of CGF is not durable. The purpose of this review is threefold. The first is to recommend more comparative studies between CGF and other platelet concentrates. The second is to constitute a continuous drug delivery system by combining CGF with other biomaterials. Finally, the novel use of CGF in facial regenerative and reconstructive medicine will be highlighted.

METHODS

A comprehensive review of literature regarding the use of CGF in facial regenerative and reconstructive medicine was performed. Based on the inclusion and exclusion criteria, a total of 135 articles were included.

RESULTS

The use of CGF involving facial rejuvenation, cartilage grafting, facial bone defects, facial peripheral nerve injury and wounding is reviewed. The reconstructive and regenerative principles lie in firm fibrin scaffolds and continuous in situ delivery of multiple growth factors.

CONCLUSIONS

CGF represents an advance in personalized medicine concept. However, the current scientific evidences about the use of CGF are limited. More basic and clinical studies should be conducted to understand the characteristics and clinical application of CGF.

LEVEL OF EVIDENCE V

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Therapeutic outcomes of non-grafted and platelet concentrations-grafted transcrestal maxillary sinus elevation (TSFE): a systematic review and meta-analysis

To evaluate and compare the stability, quantity and quality of bone augmentation at maxillary sinus elevation sites by non-grafted transcrestal sinus floor elevation (TSFE) and platelet concentration grafted transcrestal sinus floor elevation (PC-TSFE). A complete literature search was performed up to April 2019. Clinical controlled trials, retrospective cohort studies, and prospective cohort studies were selected based on inclusion criteria. The clinical outcomes were implant survival rate (ISR), marginal/crestal bone loss (MBL/CBL) and endo-sinus bone gain (ESBG). Meta‐analysis was conducted on these 1-year based values. Furthermore, another meta-analysis on 1-year ISR value was conducted among studies with different residual bone heights (RBH) within the non-grafted TSFE group. A total of 18 studies were included: 13 in TSFE group and 5 in PC-TSFE group. No significant differences were displayed between the 1-year ISR of TSFE (97%, 95%CI = 0.96–0.99) and PC-TSFE group (99%, 95%CI = 0.97–1.00). Among the various studies with different RBH within TSFE group, no significant differences in 1-year ISR were displayed. The 1-year MBL/CBL value of PC-TSFE group (0.73 mm, 95%CI = 0.43–1.13 mm) did not show significant difference as compared to TSFE group (0.60 mm, 95%CI = 0.10–1.10 mm). Furthermore, no significant enhancement was observed on 1-year ESBG value on PC-TSFE group (3.51 mm, 95%CI = 2.31–4.71 mm) in comparison with the TSFE group (2.87 mm, 95%CI = 2.18m–3.55 mm). Grafting platelet concentrations around dental implants at TSFE sites did not significantly enhance the adjacent bone regeneration. Moreover, TSFE was shown to be a reliable therapeutic option for implant sites that need simultaneous maxillary sinus augmentation, even under limited RBH.

Concentrated Growth Factors Extracted from Blood Plasma Used to Repair Nasal Septal Mucosal Defect After Rhinoplasty

BACKGROUND

To assess preliminarily the effect of concentrated growth factor (CGF) for repair of nasal septal mucosal defect after rhinoplasty.

METHODS

Ten women with mucosal defects of the nasal septum were enrolled from May 2017 to May 2018. Liquid and gel CGF was prepared from each patient's blood sample using a Medifuge system, including benchtop centrifuge. After debridement of the defect, the prepared liquid CGF was injected around the wound, and a membranous CGF film was applied to the surface. Vaseline gauze was used to pack the nostrils. All patients were treated with CGF at intervals from 3 to 5 days.

RESULTS

After 3 to 12 treatments, all the patients achieved successful repair of the nasal septal mucosal defect, with good appearance and function. During a follow-up of 3 to 6 months, no recurrence was observed.

CONCLUSION

CGF appeared to have great curative effect for patients with nasal septal mucosal defects after rhinoplasty. The procedure was easy to perform and should be considered worthwhile in clinical practice.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

In vitro and in vivo effects of concentrated growth factor on cells and tissues

This article reviews the biological outcome of the concentrated growth factor (CGF), a new platelet derivative used for tissue regeneration, in published articles related to the use of this product in basic and clinical studies. An electronic literature research using PubMed and SCOPUS was performed using combination of keywords: "concentrated growth factor" (OR "CGF"), AND "stem cells," AND "cells" OR "cell proliferation" OR "cell migration" OR "cell differentiation," AND "repair" OR "survival" OR "revitalization," AND "tissue" OR "bone." Forty-five articles that were published between 2012 and 2020 met the inclusion criteria. These studies have used CGF as fresh solid form, freeze-dried, membrane, extract, or exudate. Most studies demonstrate the positive effects of CGF in a dose-dependent manner under certain concentrations. Studies comparing CGF with other platelet concentrates, report lower efficiency, no statistically significant differences, or better results for CGF. Combination of CGF with stem cells and biomaterials significantly improves bone regeneration and the effect of allograft or collagen membrane is better than CGF alone. For a better examination of the biological outcomes of CGF, the standardization of CGF preparation regarding the choice of the test tube material for blood collection, the required volume of blood, the necessary count of platelets in CGF, and the most appropriate type of CGF are recommended.

The use of concentrated growth factor in dental implantology: A systematic review

In the era of evidence based dentistry, a well-documented consolidated data about improvements in dentistry is a necessity. Concentrated growth factor (CGF) is an emerging trend in periodontology and now in implant dentistry. Various studies have been published in the literature evaluating the effect of CGF on implant osseointegration, implant stability, survival rate, sinus augmentation, and peri-implant defects. However, no systematic review has yet been documented. The present systematic review, being first of its kind, aimed to evaluate the potential outcomes of employing CGF in implant treatment. A literature search was carried out in PubMed and Google scholar for articles published between 2001 and 2019, with various keywords such as "CGF," "dental implant," "bone regeneration," "CGF," and "osseointegration." The screening of studies was done according to PRISMA guidelines. A total of eleven studies were included in this review. Majority of the included studies pointed toward the beneficial effects of CGF in implant treatment. CGF was seen to promote osseointegration and enhance bone regeneration. Although more clinical studies are required to validate the potential merits of CGF in the long run, the preliminary results seem promising.

The Role of Platelet Concentrates in Facial Fat Grafting

Autologous fat grafting is increasingly being used as a method for the repair of facial soft tissue defects and facial rejuvenation, given its low risk of adverse effects and high efficacy. However, the unpredictability of graft retention is a limitation of this procedure. In addition, there is no standard procedure to date for autologous fat grafting. Different methods have been developed to increase the retention of grafted fat. For instance, platelet concentrates have been used to directly deliver bioactive factors to grafted fat. Platelet concentrates also provide incidental therapeutic benefits by enhancing the persistence of fat grafted in the face via the release of growth factors and cytokines. In this review, we describe current strategies for improving the survival of facial fat grafts, mainly focusing on the application of growth factors/cytokines and platelet concentrates to fat grafting.

Effect of autogenous growth factors released from platelet concentrates on the osteogenic differentiation of periodontal ligament fibroblasts: a comparative study

Background

Platelet concentrates have been used in tissue regeneration. The purpose of this study was to examine effects of growth factors released from leukocyte- and platelet-rich fibrin (L-PRF) and concentrated growth factor (CGF) on the osteogenic differentiation of periodontal ligament fibroblasts (PDLFs).

Methods

Leukocyte- and platelet-rich fibrins, CGFs and PDLFs were obtained from New Zealand rabbits. The release of basic fibroblast growth factor (bFGF), bone morphogenetic protein 2 (BMP-2) and transforming growth factor β1 (TGF-β1) from L-PRFs and CGFs was measured at 5 h and 1, 3, 5, 7 days, using the enzyme linked immunosorbent assay. The PDLFs were treated with exudates of L-PRF or CGF. After the treatment, cell counting kit-8 assay was performed at day 1, 3, 5 and 7. Alkaline phosphatase (ALP) assay and Western blotting were applied at day 7. Three blocking antibodies were used to neutralize the proteins of bFGF, BMP-2 and TGF-β1.

Results

Leukocyte- and platelet-rich fibrin and CGF showed different growth factor release pattern, but similar accumulated concentration of these growth factors. PDLFs proliferation was significantly promoted by both L-PRF and CGF at day 1, 3 and 7, and CGF group was superior to L-PRF group at day 1 and 3. Both L-PRF and CGF significantly enhanced PDLFs ALP activity and protein expression of osteogenic markers. The osteopontin level was higher in CGF group than in L-PRF group, but no significant differences were found between two groups for ALP activity. Three blocking antibodies significantly downregulated both L-PRF and CGF induced osteogenic markers expression.

Conclusion

Both CGF and L-PRF can promote the proliferation and osteogenic differentiation of PDLFs. The bFGF, BMP-2 and TGF-β1 are involved in both L-PRF and CGF induced osteogenic differentiation of PDLFs.

The role of concentrated growth factor on implant stability: A preliminary study

PURPOSE

The purpose of this preliminary study was to evaluate the effect of concentrated growth factor (CGF) on dental implant stability in type 2 bone using the resonance frequency analysis (RFA) device Smartpeg®.

METHODS

The researchers carried out a prospective cohort study on a sample group composed of 12 patients (mean age=67) who required dental implants. Implant socket preparation (with and without CGF) was the primary predictor variable. In each patient, two dental implants were inserted in the anterior mandible. For the test group, one dental implant socket was covered with CGF membrane, while the other socket was prepared conventionally for the control group. Implant stability, as measured by RFA, was the outcome variable. Measurements were taken using the Ostell device at the time of implant placement and at the 1st, 2nd and 4th weeks.

RESULTS

Mean implant stability quotients (ISQs) were 67.00±4.573 for the study group and 64.75±5.065 for the control group. The difference between the two groups was not statistically significant.

CONCLUSION

It was found that CGF did not provide beneficial effect on dental implant stability in the early healing period in type 2 bone.

Concentrated Growth Factors Can Inhibit Photoaging Damage Induced by Ultraviolet A (UVA) on the Human Dermal Fibroblasts In Vitro

BACKGROUND Photoaging is the main cause of extrinsic skin aging. Daily exposure to ultraviolet A (UVA) accelerates the process of photoaging. The present study aimed to understand the role of concentrated growth factors (CGF) on UVA irradiated human skin cells. MATERIAL AND METHODS We isolated and subcultured normal human dermal fibroblasts (NHDFs) from 6 different human dorsal skins and established photoaging models of NHDFs irradiated by UVA to detect the influence of CGF on fibroblasts in vitro. Three groups were examined: normal, cellular photoaging model (total dosages of 18J·cm--⁻²-), and cellular photoaging model plus CGF. In our study, we used the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay method to measure the cell viability. We also used reactive oxygen species (ROS) assay and superoxide dismutase (SOD) assay to measure respectively the amount of oxygen free radicals and antioxidative enzymes. We compared the migration rates among the photoaging model groups, the control groups, and the CGF-treated culture medium groups that were irradiated. RESULTS Our study results indicated that 5% CGF can reduce UVA-induced human skin fibroblasts damage significantly, improve the viability of NHDFs significantly, and largely decrease the UVA irradiation effect (P<0.05). The migration rates of the normal group and the UVA-irradiated NHDFs in the 5% CGF group had significantly increased migration rates (P<0.05), compared to the control medium group. The migration rates of the UVA-irradiated NHDFs in 5% CGF exceed those of the normal group. These results showed that 5% CGF could greatly promote cellular proliferation, migration, and SOD at the same time that the amounts of ROS were markedly decreased. CONCLUSIONS These experimental findings offer some important insights into CGF's capacity for scavenging ROS, improving SOD, and increasing migration rates in NHDFs irradiated by UVA.

Concentrated Growth Factors as an Ingenious Biomaterial in Regeneration of Bony Defects after Periapical Surgery: A Report of Two Cases

The overall success of a periapical surgery is assessed in terms of regeneration of functional periradicular tissues. The regenerative potential of platelets has been well documented. This article describes the use of concentrated growth factors (CGF), a new family of autologous platelet concentrates, as a sole material for bone regeneration after periapical surgery. 32- and 35-year-old female patients diagnosed with Ellis Class IV, an open apex in 11 with apical periodontitis in 11 and 12 and previously root canal-treated 31 and 41 with a chronic apical abscess, respectively, were managed with endodontic surgery. Subsequent to apicectomy and retrograde filling, the CGF fibrin block and membrane were used before suturing. There was uneventful healing during the immediate post-op and the subsequent follow-up periods. CGF is produced by a differential centrifugation process that results in the formation of a denser fibrin matrix richer in growth factors than those observed in PRF. Reasonable osseous healing was seen as early as 6-month follow-up, thereby recommending the use of CGF as an alternative to bone grafts and membranes in extensive periapical lesions to enhance bone regeneration and to decrease the healing time.

Effects of concentrated growth factor on proliferation, migration, and differentiation of human dental pulp stem cells in vitro

Concentrated growth factor, a novel autologous plasma extract, contained various growth factors which promoted tissue regeneration. In this study, we aimed to investigate the biological effects of concentrated growth factor on human dental pulp stem cells. The microstructure and biocompatibility of concentrated growth factor scaffolds were evaluated by scanning electron microscopy. Cell proliferation and migration, odontoblastic and endothelial cell differentiation potential were assessed after exposing dental pulp stem cells to different concentrations (5%, 10%, 20%, 50%, or 80%) of concentrated growth factor extracts. The results revealed that concentrated growth factor scaffolds possessed porous fibrin network with platelets and leukocytes, and showed great biocompatibility with dental pulp stem cells. Higher cell proliferation rates were detected in the concentrated growth factor–treated groups in a dose-dependent manner. Interestingly, in comparison to the controls, the low doses (<50%) of concentrated growth factor increased cell migration, alkaline phosphatase activity, and mineralized tissue deposition, while the cells treated in high doses (50% or 80%) showed no significant difference. After stimulating cell differentiation, the expression levels of dentin matrix protein-1, dentin sialophosphoprotein, vascular endothelial growth factor receptor-2 and cluster of differentiation 31 were significantly upregulated in concentrated growth factor–supplemented groups than those of the controls. Furthermore, the dental pulp stem cell–derived endothelial cells co-induced by 5% concentrated growth factor and vascular endothelial growth factor formed the most amount of mature tube-like structures on Matrigel among all groups, but the high-dosage concentrated growth factor exhibited no or inhibitory effect on cell differentiation. In general, our findings confirmed that concentrated growth factor promoted cell proliferation, migration, and the dental pulp stem cell–mediated dentinogenesis and angiogenesis process, by which it might act as a growth factor–loaded scaffold to facilitate dentin–pulp complex healing.

The use of fat grafting and platelet-rich plasma for wound healing: A review of the current evidence

Fat grafting is becoming a common procedure in regenerative medicine because of its high content of growth factors and adipose derived stem cells (ADSCs) and the ease of harvest, safety, and low cost. The high concentration of ADSCs found in fat has the potential to differentiate into a wide range of wound-healing cells including fibroblasts and keratinocytes as well as demonstrating proangiogenic qualities. This suggests that fat could play an important role in wound healing. However retention rates of fat grafts are highly variable due in part to inconsistent vascularisation of the transplanted fat. Furthermore, conditions such as diabetes, which have a high prevalence of chronic wounds, reduce the potency and regenerative potential of ADSCs. Platelet-rich plasma (PRP) is an autologous blood product rich in growth factors, cell adhesion molecules, and cytokines. It has been hypothesised that PRP may have a positive effect on the survival and retention of fat grafts because of improved proliferation and differentiations of ADSCs, reduced inflammation, and improved vascularisation. There is also increasing interest in a possible synergistic effect that PRP may have on the healing potential of fat, although the evidence for this is very limited. In this review, we evaluate the evidence in both in vitro and animal studies on the mechanistic relationship between fat and PRP and how this translates to a benefit in wound healing. We also discuss future directions for both research and clinical practice on how to enhance the regenerative potential of the combination of PRP and fat.

[An in vitro study of the angiogenic effects of concentrate growth factor on human umbilical vein endothelial cells]

OBJECTIVE

This study aimed to explore the effects of concentrate growth factor extracts (CGFe) on human umbilical vein endothelial cells (HUVECs) in vitro.

METHODS

Concentrate growth factor (CGF) were prepared from the peripheral blood of healthy donors, followed by CGFe. Four groups were designed based on cell culture medium, as follows: 2%CGFe, 5%CGFe, 10%CGFe, and control. The proliferation activity of HUVECs was detected by cell cycle and CCK-8 assays. The migration of HUVECs was detected by scratch assay. The mRNA expression levels of vascular endothelial growth factor (VEGF), chemokine receptor 4 (CXCR4), and platelet derived growth factor (PDGF) were examined by quantitative real time polymerase chain reaction (qRT-PCR).

RESULTS

Results of CCK-8 and cell cycle assays showed that CGFe promoted the proliferation capability of HUVECs in a dose-dependent manner, and the data had statistical significance among four groups (P<
0.05). The cell migration assay indicated that CGF accelerated wound closure in a dose-dependent manner after 12 h of culture (P<0.05). The results of qRT-PCR showed that CGF upregulated the expression levels of VEGF, CXCR4, and PDGF in HUVECs.

CONCLUSIONS

CGFe can promote the proliferation, migration, and angiogenic differentiation of HUVECs. Thus, CGF might be an appropriate cure for dental pulp revascularization.

Beneficial Effects of Concentrated Growth Factors and Resveratrol on Human Osteoblasts In Vitro Treated with Bisphosphonates

Bisphosphonates are primary pharmacological agents against osteoclast-mediated bone loss and widely used in the clinical practice for prevention and treatment of a variety of skeletal conditions, such as low bone density and osteogenesis imperfecta, and pathologies, such as osteoporosis, malignancies metastatic to bone, Paget disease of bone, multiple myeloma, and hypercalcemia of malignancy. However, long-term bisphosphonate treatment is associated with pathologic conditions including osteonecrosis of the jaw, named BRONJ, which impaired bone regeneration process. Clinical management of BRONJ is controversy and one recent approach is the use of platelet concentrates, such as Concentrated Growth Factors, alone or together with biomaterials or antioxidants molecules, such as resveratrol. The aim of the present study was to investigate the in vitro effects of Concentrated Growth Factors and/or resveratrol on the proliferation and differentiation of human osteoblasts, treated or not with bisphosphonates. Human osteoblasts were stimulated for 3 days in complete medium and for 21 days in mineralization medium. At the end of the experimental period, the in vitro effect on osteoblast proliferation and differentiation was evaluated using different techniques such as MTT, ELISA for the quantification/detection of osteoprotegerin and bone morphogenetic protein-2, immunohistochemistry for sirtuin 1 and collagen type I, and the Alizarin Red S staining for the rate of mineralization. Results obtained showed that Concentrated Growth Factors and/or resveratrol significantly increased osteoblast proliferation and differentiation and that the cotreatment with Concentrated Growth Factors and resveratrol had a protective role on osteoblasts treated with bisphosphonates. In conclusion, these data suggest that this approach could be promised in the clinical management of BRONJ.

Influence of Genetically Modified Human Umbilical Cord Blood Mononuclear Cells on the Expression of Schwann Cell Molecular Determinants in Spinal Cord Injury

Spinal cord injury (SCI) unavoidably results in death of not only neurons but also glial cells. In particular, the death of oligodendrocytes leads to impaired nerve impulse conduction in intact axons. However, after SCI, the Schwann cells (SCs) are capable of migrating towards an area of injury and participating in the formation of functional myelin. In addition to SCI, cell-based therapy can influence the migration of SCs and the expression of their molecular determinants. In a number of cases, it can be explained by the ability of implanted cells to secrete neurotrophic factors (NTFs). Genetically modified stem and progenitor cells overexpressing NTFs have recently attracted special attention of researchers and are most promising for the purposes of regenerative medicine. Therefore, we have studied the effect of genetically modified human umbilical cord blood mononuclear cells on the expression of SC molecular determinants in SCI.

Mutation of N-linked glycosylation in EpCAM affected cell adhesion in breast cancer cells

Epithelial cell adhesion molecule (EpCAM) expression is elevated in breast cancer tissue, and correlates with the cancer metastasis and cell adhesion. Although EpCAM glycosylation is supposed to be associated with its function, the contribution of N-glycosylation to its function remains unclear. Here we analyzed cell adhesion ability of EpCAM in breast cancer cells. The results showed that EpCAM expression was associated with cell adhesion and N-glycosylation mutation of EpCAM decreased adhesion capacity. N-glycosylation mutation of EpCAM was correlated with lower levels of integrin β1 and fibronectin. We also found that effect of N-glycosylation of EpCAM on cell adhesion was regulated via FAK/Akt/Gsk-3β/β-catenin signaling pathway, which further adjusted MMP2/9 expression and activities. Our studies identified the characteristics and function of EpCAM glycosylation sites on breast cancer cell adhesion. These data could potentially clarify molecular regulation of EpCAM by N-glycosylation and intensify our understanding of the utility of glycosylated EpCAM as a target for breast cancer therapy.

Platelet-rich plasma for regeneration of neural feedback pathways around dental implants: a concise review and outlook on future possibilities

Along with the development of new materials, advanced medical imaging and surgical techniques, osseointegrated dental implants are considered a successful and constantly evolving treatment modality for the replacement of missing teeth in patients with complete or partial edentulism. The importance of restoring the peripheral neural feedback pathway and thus repairing the lack of periodontal mechanoreceptors after tooth extraction has been highlighted in the literature. Nevertheless, regenerating the nerve fibers and reconstructing the neural feedback pathways around osseointegrated implants remain a challenge. Recent studies have provided evidence that platelet-rich plasma (PRP) therapy is a promising treatment for musculoskeletal injuries. Because of its high biological safety, convenience and usability, PRP therapy has gradually gained popularity in the clinical field. Although much remains to be learned, the growth factors from PRP might play key roles in peripheral nerve repair mechanisms. This review presents known growth factors contributing to the biological efficacy of PRP and illustrates basic and (pre-)clinical evidence regarding the use of PRP and its relevant products in peripheral nerve regeneration. In addition, the potential of local application of PRP for structural and functional recovery of injured peripheral nerves around dental implants is discussed.

Quantification of growth factors in different platelet concentrates

Concentrated growth factor (CGF), a new generation of platelet concentrate product, appears to have more abundant growth factors because of its special centrifugation process. However, there are few studies supporting this. This study was designed to evaluate the contents of major growth factors in CGF and compare them with those found in PRP (platelet-rich plasma) and PRF (platelet-rich fibrin). PRP, PRF, and CGF were obtained from the same samples of peripheral blood. Concentrations of five representative growth factors in platelets were measured with enzyme-linked immunosorbent assay (ELISA): platelet-derived growth factor-BB (PDGF-BB), transforming growth factor β-1 (TGF-β1), insulin-like growth factor-1 (IGF-1), vascular endothelial growth factor (VEGF), and basic fibroblast growth factor (bFGF). The results showed that the bFGF levels in CGF and PRF were significantly higher than that in activated PRP. For other growth factors, such as PDGF-BB, TGF-β1, IGF-1, and VEGF, the levels did not differ significantly among activated PRP, PRF, and CGF. Our findings extended the currently available data on the release and measurement of growth factors in CGF and other platelet gels. In future studies, we need more data to find the proper therapeutic doses for platelet concentrates suitable for different clinical applications.

Schwann cells genetically modified to express S100A4 increases GAP43 expression in spiral ganglion neurons in vitro

Schwann cells (SCs) have been reported as a possible source of neurotrophic support for spiral ganglion neurons (SGNs). This study was aimed to investigate whether S100A4 was contributed in the functional effects of SCs on SGNs. SCs were transfected with S100A4 vector or small interfering RNA (siRNA) against S100A4, and the transfection efficiency was verified by quantitative PCR (qPCR) and Western blot. The migration of transfected SCs was determined by Transwell assay, and the expression levels of vascular endothelial growth factor precursor (VEGF) and matrix metallopeptidase 9 (MMP-9) were measured by Western blot. Co-culture of either S100A4 overexpressed or suppressed SCs with SGNs, and the growth associated protein 43 (GAP43) expression in SGNs was detected by immunofluorescence (IF), qPCR and Western blot. The migration of SCs was significantly enhanced by S100A4 overexpression (P < 0.001), while was suppressed by S100A4 knockdown (P < 0.01). Further, the expressions of VEGF and MMP-9 were notably up-regulated by S100A4 overexpression, while were down-regulated by S100A4 knockdown. Moreover, co-culture with the S100A4 overexpressed SCs significantly increased the expression of GAP43 in SGNs (P < 0.01). As expected, co-culture with S100A4 knockdown SCs decreased GAP43 level (P < 0.05). S100A4 enhanced the migratory ability of SCs. SCs genetically modified to overexpress the S100A4 could up-regulate the GAP43 expression in SGNs.