Effect of Concentrated Growth Factor (CGF) on the Promotion of Osteogenesis in Bone Marrow Stromal Cells (BMSC) in vivo

The effect of human umbilical cord mesenchymal stem cells combined with concentrated growth factor on repairing necrotic pulp caused by dental caries

This study investigated the impact of combining human umbilical cord mesenchymal stem cells (hUC-MSCs) with concentrated growth factor (CGF) on regenerating necrotic pulp. Ten-month-old male Bama miniature pigs were divided into control and caries groups. The experimental teeth were randomly divided into three groups: caries untreated, Ca(OH)2, and engineering dental pulp-like tissue (EDPT). hUC-MSCs and CGF scaffold were combined to construct EDPT, and the histological structure was observed. Odontoblasts and dental pulp cells were counted in each group. The results showed that hUC-MSCs adhered firmly to the porous mesh CGF scaffold, grew vigorously, and stretched sufficiently. In the EDPT group, odontoblasts in the root canal were arranged neatly, and predentin was formed. The odontoblast and dental pulp cell counts in the EDPT group were statistically significant compared to the caries untreated and Ca(OH)2 groups. The hUC-MSCs-CGF could successfully repair necrotic pulp in animals with dental caries.

3D-printed biomimetic bone scaffold loaded with lyophilized concentrated growth factors promotes bone defect repair by regulation the VEGFR2/PI3K/AKT signaling pathway

This study investigates the effects of concentrated growth factors (CGF) and bone substitutes on the proliferation and differentiation of bone marrow mesenchymal stem cells (BMSCs), as well as the development of a novel 3D-printed biomimetic bone scaffold. Based on the structure of cancellous bone, 3D-printed bionic bone with sustainable release of growth factors and Ca2+ was prepared. Using BMSCs and EA.hy926 in co-culture with the bionic bone scaffold, experimental results demonstrate that this bionic structural design enhances cell proliferation and adhesion, and that the bionic bone possesses the ability to promote bone and vascular regeneration directly. Transcriptomics, western blot analysis, and flow cytometry are employed to investigate the effects of CGF and Ca2+ on the signaling pathways of BMSCs. The study reports that vascular endothelial growth factor (VEGF) released by CGF activated VEGFR2 on BMSCs, leading to Ca2+ influx and activation of the PI3K/AKT signaling pathway, thereby influencing osteogenesis. Animal experiments confirm the ability of the bionic bone to promote osteogenesis in vivo, and its unique degradation pattern accelerates the in vivo repair of bone defects. In conclusion, this study presents a novel biomimetic strategy and, for the first time, explores the potential mechanism by which VEGF and Ca2+ regulate BMSCs differentiation through the VEGFR2/PI3K/AKT signaling pathway. These insights offer a new perspective for the development of innovative bone substitute materials.

Effect of platelet-rich fibrin and concentrated growth factor on the regenerative potential of human-induced pluripotent stem cells: A comparative analysis

Background

Platelet-rich fibrin (PRF) has been used, while concentrated growth factor (CGF) has recently evolved as a bioscaffold in regenerative endodontics.

Aims

This study aimed to evaluate the effect of PRF and CGF on the proliferation, migration, and differentiation of human-induced pluripotent stem cells (hiPSCs).

Materials and Methods

CGF and PRF were fabricated from voluntarily donated human blood, and a conditioned medium was prepared. HiPSCs were isolated and cultivated on a conditioned medium for 12 days. The proliferation rate was analyzed using a trypan blue assay on days 9, 10, and 11. The migratory rate was evaluated using a wound healing assay after 24, 48, and 72 h. For assessing the differentiation of hiPSCs, various markers with quantitative real-time polymerase chain reactions on day 12 were used.

Results

Mesenchymal phenotypic transition was seen with an increase in proliferation rate in the PRF group more than in the CGF group on day 9, along with the differentiation of cells with an increase in osteoblastic markers on day 12 in both groups. The migratory capacity of cells was significantly increased in the CGF and PRF groups, with a greater increase in the CGF group.

Conclusions

CGF and PRF extend the duration of growth factor activity and enhance cell proliferation and osteogenic differentiation, with hiPSCs serving as a bioscaffold with high regenerative potential.

Bone Regeneration Facilitated by Autologous Bioscaffold Material: Liquid Phase of Concentrated Growth Factor with Dental Follicle Stem Cell Loading

The application of bioengineering techniques for achieving bone regeneration in the oral environment is an increasingly prominent field. However, the clinical use of synthetic materials carries certain risks. The liquid phase of concentrated growth factor (LPCGF), as a biologically derived material, exhibits superior biocompatibility. In this study, LPCGF was employed as a tissue engineering scaffold, hosting dental follicle cells (DFCs) to facilitate bone regeneration. Both in vivo and in vitro experimental results demonstrate that this platform significantly enhances the expression of osteogenic markers in DFCs, such as alkaline phosphatase (ALP), runt-related transcription factor 2 (Runx2), and type I collagen (Col1a1). Simultaneously, it reduces the expression of inflammation-related genes, particularly interleukin-6 (IL-6) and interleukin-8 (IL-8), thereby alleviating the negative impact of the inflammatory microenvironment on DFCs. Further investigation into potential mechanisms reveals that this process is regulated over time by the WNT pathway. Our research results demonstrate that LPCGF, with its favorable physical characteristics, holds great potential as a scaffold. It can effectively carry DFCs, thereby providing an optimal initial environment for bone regeneration. Furthermore, LPCGF endeavors to closely mimic the mechanisms of bone healing post-trauma to facilitate bone formation. This offers new perspectives and insights into bone regeneration engineering.

The effect of platelet-rich fibrin, platelet-rich plasma, and concentrated growth factor in the repair of full thickness rotator cuff tears

BACKGROUND

Rotator cuff lesions rank among the prevalent causes of shoulder pain. Combining surgical interventions with growth factors, scaffolds, and stem cell therapies can effectively decrease the likelihood of rotator cuff repair recurrence. Platelet-rich plasma (PRP), platelet-rich fibrin (PRF), and concentrated growth factor (CGF), isolated from blood and rich in growth factors, have a critical role in cell migration, cell proliferation, and angiogenesis during the tissue regeneration process. Investigations have further substantiated the beneficial impact of PRP and PRF on the biomechanical and histologic attributes of the tendon-bone interface. We aimed to investigate the effectiveness of CGF compared with PRF and PRP in the repair of rotator cuff lesions as a new treatment strategy.

METHODS

Incision was performed on both shoulder regions of 21 adult rabbits. After 8 weeks, both shoulders of the rabbits were repaired by suturing. PRF and CGF were administered to 2 separate groups along with the repair. Tissues were collected for biomechanical measurements and histologic evaluations.

RESULTS

Histologically, CGF, PRF, and PRP showed similar results to the healthy control group. The level of improvement was significant in the PRF and PRP groups. In the PRF group, the distribution of Ki67 (+), CD31 (+), and CD34 (+) cells was determined intensely in the tendon-bone junction regions. Apoptotic cells increased significantly in the repair group compared with the healthy group, whereas fewer apoptotic cells were found in the PRF-, PRP-, and CGF-applied groups. In the biomechanical results, no statistical difference was recorded among the groups.

CONCLUSION

The use of PRF, PRP, and CGF in rotator cuff repair shows promise in shortening the treatment period and preventing the recurrence of rotator cuff lesions.

Plasma Rich in Growth Factors in Bone Regeneration: The Proximity to the Clot as a Differential Factor in Osteoblast Cell Behaviour

The osteogenic differentiation process, by which bone marrow mesenchymal stem cells and osteoprogenitors transform into osteoblasts, is regulated by several growth factors, cytokines, and hormones. Plasma Rich in Growth Factors (PRGF) is a blood-derived preparation consisting of a plethora of bioactive molecules, also susceptible to containing epigenetic factors such as ncRNAs and EVs, that stimulates tissue regeneration. The aim of this study was to investigate the effect of the PRGF clot formulation on osteogenic differentiation. Firstly, osteoblast cells were isolated and characterised. The proliferation of bone cells cultured onto PRGF clots or treated with PRGF supernatant was determined. Moreover, the gene expression of Runx2 (ID: 860), SP7 (ID: 121340), and ALPL (ID: 249) was analysed by one-step real-time quantitative polymerase chain reaction (RT-qPCR). Additionally, alkaline phosphatase (ALPL) activity determination was performed. The highest proliferative effect was achieved by the PRGF supernatant in all the study periods analysed. Concerning gene expression, the logRGE of Runx2 increased significantly in osteoblasts cultured with PRGF formulations compared with the control group, while that of SP7 increased significantly in osteoblasts grown on the PRGF clots. On the other hand, despite the fact that the PRGF supernatant induced ALPL up-regulation, significantly higher enzyme activity was detected for the PRGF clots in comparison with the supernatant formulation. According to our results, contact with the PRGF clot could promote a more advanced phase in the osteogenic process, associated to higher levels of ALPL activity. Furthermore, the PRGF clot releasate stimulated a higher proliferation rate in addition to reduced SP7 expression in the cells located at a distant ubication, leading to a less mature osteoblast stage. Thus, the spatial relationship between the PRGF clot and the osteoprogenitors cells could be a factor that influences regenerative outcomes.

Osteogenesis or Apoptosis-Twofold Effects of Zn2+ on Bone Marrow Mesenchymal Stem Cells: An In Vitro and In Vivo Study

Zinc (Zn) is a bioabsorbable metal that shows great potential as an implant material for orthopedic applications. Suitable concentrations of zinc ions promote osteogenesis, while excess zinc ions cause apoptosis. As a result, the conflicting impacts of Zn2+ concentration on osteogenesis could prove to be significant problems for the creation of novel materials. This study thoroughly examined the cell viability, proliferation, and osteogenic differentiation of rat bone marrow mesenchymal stem cells (rBMSCs) cultured in various concentrations of Zn2+ in vitro and validated the osteogenesis effects of zinc implantation in vivo. The effective promotion of cell survival, proliferation, migration, and osteogenic differentiation of bone marrow mesenchymal stem cell (BMSCs) may be achieved at a low concentration of Zn2+ (125 μM). The excessively high concentration of zinc ions (>250 μM) not only reduces BMSCs' viability and proliferation but also causes them to suffer apoptosis due to the disturbed zinc homeostasis and excessive Zn2+. Moreover, transcriptome sequencing was used to examine the underlying mechanisms of zinc-induced osteogenic differentiation with particular attention paid to the PI3K-AKT and TGF-β pathways. The present investigation elucidated the dual impacts of Zn2+ microenvironments on the osteogenic characteristics of rBMSCs and the associated processes and might offer significant insights for refining the blueprint for zinc-based biomaterials.

Novel Applications of Concentrated Growth Factors in Facial Rejuvenation and Plastic Surgery

Concentrated growth factor (CGF), which is a third-generation platelet concentrate product, exhibits good potential for repair and regeneration of soft and hard tissues, and has gradually attracted attention in the field of cosmetic plastic surgery. The purpose of this review is to summarize the application and research of CGF in the field of facial rejuvenation and plastic surgery. A comprehensive review of the literature about the applications of CGF in facial rejuvenation and plastic surgery was conducted in PubMed, Ovid MEDLINE, and Web of Science. According to the inclusion and exclusion criteria, a total of 22 articles were included in this review. In recent years, CGF has been applied in many aspects in the field of facial rejuvenation and plastic surgery, including skin photoaging, repairment of soft-tissue defects, rhinoplasty, hair loss, autologous fat transplantation, and scars. In addition, no significant adverse reactions have been reported so far. CGF is rich in high-concentration growth factors, which has great potential and application prospects in facial rejuvenation and plastic surgery. However, the applications of CGF still have some problems, such as the mechanism, time of decomposition, and long-term efficacy and safety, which are needed to be resolved in future.

A pH-neutral bioactive glass empowered gelatin-chitosan-sodium phytate composite scaffold for skull defect repair

The ideal skull defect repairing material should have good biocompatibility and mechanical properties, and contribute to osteogenesis. In this study, we designed and fabricated biodegradable, bioactive and mechanically robust porous scaffolds composed completely of biological materials. We used a gelatin-chitosan blend as the matrix, sodium phytate instead of toxic glutaraldehyde for cross-linking, and the pH-neutral bioactive glass (PSC) to improve biological activity and mechanical properties. The chitosan-gelatin-30%PSC/sodium phytate composite scaffold avoided the problems of high toxicity in conventional cross-linking agents with glutaraldehyde, the poor mechanical support of the pure chitosan or gelatin scaffold, and the mismatch of the degradation rate with bone repair, becoming a promising new candidate for skull defect repair.

Efficacy of concentrated growth factor (CGF) in the surgical treatment of oral diseases: a systematic review and meta-analysis

BACKGROUND

Concentrated growth factor (CGF), a new autologous platelet concentrate, has been widely investigated to the adjunctive treatment of oral diseases. This study aims to evaluate the efficacy of CGF in the surgical treatment of oral diseases.

METHODS

MEDLINE, Web of Science, Scopus, Cochrane, and EMBASE databases were searched up to July 2023. Only randomized clinical trials were included. The methodologic quality was evaluated by the Cochrane Risk of Bias Tool. RevMan 5.4 software was used for data analysis.

RESULTS

In the treatment of periodontal intrabony defects, bone graft combined with CGF was significantly superior to bone graft (P < 0.01), with mean intrabony defect depth reduction of 1.41 mm and mean clinical attachment level gain of 0.55 mm. In the regenerative surgery of furcation defects, the effect of CGF group was significantly better than control group (P < 0.0001), with mean probing depth reduction of 0.99 mm, vertical bone gain of 0.25 mm, and horizontal bone gain of 0.34 mm. CGF combined with coronally advanced flap (CAF) was more effective than CAF alone (mean keratinized tissue width increase of 0.41 mm, mean gingival thickness increase of 0.26 mm, P < 0.00001), but less effective than connective tissue graft (CTG) combined with CAF (mean root coverage difference of -15.1%, mean gingival thickness difference of -0.5 mm, P < 0.0001). In the alveolar ridge preservation, additional use of CGF reduced horizontal bone resorption by 1.41 mm and buccal vertical bone resorption by 1.01 mm compared to control group (P < 0.0001). The VAS score of CGF group was significantly lower than that of the control group at the 1st and 7th day after oral surgery (P < 0.0001).

CONCLUSIONS

CGF can exert a positive adjunctive effect for the regenerative surgery of periodontal intrabony defects, furcation defects, and alveolar ridge preservation procedure. CGF combined with CAF has a better therapeutic effect on gingival recession compared to CAF alone, although it is not as effective as CTG combined with CAF. CGF could promote postoperative healing and pain relief in oral surgery within a week. There is currently not enough evidence to support the clinical benefits of CGF in other oral surgeries.

Effect of calcium carbonate nanoparticles, silver nanoparticles and advanced platelet-rich fibrin for enhancing bone healing in a rabbit model

This study aimed to evaluate the efficacy of calcium carbonate nanoparticles (CCNPs) to induce new bone formation in a critical size segmental bone defect in rabbit's radius when used alone, combined with silver nanoparticles (AgNPs) as a paste, or as a composite containing CCNPs, AgNPs, and advanced platelet-rich fibrin (A-PRF). Thirty-six adult apparently healthy male New Zealand White rabbits aging from 5 to 6 months and weighting 3.5 ± 0.5 kg were used. The animals were divided into four groups; control group, CCNPs group, CCNPs/AgNPs paste group, and CCNPs/AgNPs/A-PRF composite group. The animals were investigated at 4, 8, and 12 weeks post-implantation in which the healing was evaluated using computed tomographic (CT) and histopathological evaluation. The results revealed that CCNPs/AgNPs paste and CCNPs/AgNPs/A-PRF composite has a superior effect regarding the amount and the quality of the newly formed bone compared to the control and the CCNPs alone. In conclusion, addition of AgNPs and/or A-PRF to CCNPs has reduced its resorption rate and improved its osteogenic and osteoinductive properties.

Incidence and risk factors for surgical site infection after medial opening-wedge high tibial osteotomy using a locking T-shape plate

Medial opening-wedge high tibial osteotomy (MOWHTO) is a well-established surgical method for treatment of isolated medial compartment osteoarthritis with varus deformity, but the surgical outcomes may be compromised by surgical site infection (SSI). This study aimed to investigate the incidence and the risk factors for SSI after MOWHTO. This retrospective study included consecutive patients who underwent MOWHTO for isolated medial compartment osteoarthritis with varus deformity in two tertiary referral hospitals from January 2019 and June 2021. Patients who developed SSI within 12 months of surgery were identified by inquiring the medical records for index hospitalisation, notes of after-discharge outpatient visits, or records of readmission for treatment of SSI. Univariate comparisons were performed to detect the differences between SSI and non-SSI groups, and multivariate logistic regression analysis was used to identify the independent risk factors. Six hundred sixteen patients with 708 procedures were included and 30 (4.2%) cases of SSI occurred, with 0.6% rate for deep SSI and 3.6% for superficial. Univariate analyses showed significant difference between groups in terms of morbidity obesity (≥32 kg/m2 ) (20.0% vs 8.9%), comorbid diabetes (26.7% vs 11.1%), active smoking (20.0% vs 6.3%), time from admission to operation (5.2 ± 4.0 vs 4.1 ± 3.0), size of osteotomy ≥12 mm (40.0% vs 20.0%), type of bone grafting and lymphocyte count (2.1 ± 0.5 vs 1.9 ± 0.6). However, in the multivariate analysis, only active smoking (OR, 3.4; 95% CI, 1.4-10.2), size of osteotomy ≥12 mm (OR, 2.8; 95% CI, 1.3-5.9) and allogeneic/artificial vs no bone grafting (OR, 2.4; 95% CI, 1.0-10.8) remained significant. SSI was not uncommon after MOWHTO, but the majority was superficial. The identified three independent factors, including smoking, size of osteotomy ≥12 mm and allogeneic/artificial bone grafting would help risk assessment and stratification, target risk factor modification and clinical surveillance, and inform patient counselling.

Alveolar ridge preservation in post-extraction sockets using concentrated growth factors: a split-mouth, randomized, controlled clinical trial

Aim

The aim of this clinical trial was to assess the impact of autologous concentrated growth factor (CGF) as a socket-filling material and its ridge preservation properties following the lower third molar extraction.

Materials and methods

A total of 60 sides of 30 participants who had completely symmetrical bilateral impacted lower third molars were enrolled. The primary outcome variables of the study were bone height and width, bone density, and socket surface area in the coronal section. Cone beam computed tomography images were obtained immediately after surgery and three months after surgery as a temporal measure. Follow-up data were compared to the baseline using paired and unpaired t-tests.

Results

CGF sites had higher values in height and width when compared to control sites (Buccal wall 32.9 ± 3.5 vs 29.4 ± 4.3 mm, Lingual wall 25.4 ± 3.5 vs 23.1 ± 4 mm, and Alveolar bone width 21.07 ± 1.55vs19.53 ± 1.90 mm, respectively). Bone density showed significantly higher values in CGF sites than in control sites (Coronal half 200 ± 127.3 vs -84.1 ± 121.3 and Apical half 406.5 ± 103 vs 64.2 ± 158.6, respectively). There was a significant difference between both sites in the reduction of the periodontal pockets.

Conclusion

CGF application following surgical extraction provides an easy, low-cost, and efficient option for alveolar ridge preservation. Thus, the use of CGF by dentists during dental extractions may be encouraged, particularly when alveolar ridge preservation is required.

Clinical trial registration

TCTR identification, TCTR20221028003.

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.

Concentrated growth factor combined with iRoot BP Plus promotes inflamed pulp repair: an in vitro and in vivo study

BACKGROUND

Platelet concentrates combined with calcium silicate cements may promote reparative dentin formation. However, few studies have reported their effect on dental pulp inflammation. This study aimed to evaluate the effects of concentrated growth factor (CGF) combined with iRoot BP Plus on inflammatory human dental pulp stem cells (hDPSCs) in vitro and inflamed pulp in rats in vivo.

METHODS

The proliferation of LPS-stimulated hDPSCs treated with 50% CGF with/without 25% iRoot BP Plus was evaluated using Cell Counting Kit-8 on days 1, 4 and 7. The expression of genes associated with inflammation on day 1 and differentiation on day 14 was analysed by real-time polymerase chain reaction. The exposed pulp of rat maxillary molars was injected with 10 mg/mL LPS and directly capped with CGF membrane with/without iRoot BP Plus extract for 1, 7 and 28 days. The teeth were subjected to histologic analyses and immunohistochemistry.

RESULTS

The proliferation rates of the inflammatory hDPSCs after the combination treatment were significantly higher than those after the other treatments on days 4 and 7 (P < 0.05). IL-1β, IL-6, and TNF-α levels were increased in inflammatory hDPSCs but decreased after treatment with CGF combined with iRoot BP Plus extract, whereas IL-4 and IL-10 showed the opposite expression patterns. Expression of the odontogenesis-related genes OCN, Runx2, and ALP was dramatically enhanced by combined treatment with CGF and iRoot BP Plus extract. In rat pulp, the average inflammation scores of the CGF and CGF-iRoot BP Plus groups significantly decreased in comparison with those of the LPS group (P < 0.05), and the CGF-iRoot BP Plus group had more reparative dentin than the CGF and BP groups. Immunohistochemical staining showed fewer M1 macrophages on day 1 and more M2 macrophages on day 7 in the CGF-iRoot BP Plus group than in the other groups.

CONCLUSIONS

The combination of CGF and iRoot BP Plus showed a synergistic effect on anti-inflammatory potential and promoted greater pulp healing than CGF or iRoot BP Plus alone.

Efficacy of concentrated growth factor combined with grafting materials vs. grafting materials alone for the treatment of periodontal intrabony defects: a systematic review and meta-analysis

Background

Concentrated growth factor (CGF) is a novel biomaterial that can effectively promote tissue growth, but it is uncertain whether adding CGF can product additional effects in the periodontal tissue growth. The purpose of this meta-analysis was to assess the efficacy of CGF combined with grafting materials versus grafting materials alone for the treatment of periodontal intrabony defects.

Methods

The PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure (CNKI), China Biology Medicine Disc (CBM), Wanfang, and VIP databases were searched from inception date to June 2022. The inclusion criteria were: (I) randomized controlled trials (RCTs) comparing CGF combined with grafting materials with the single use of grafting materials for the treatment of periodontal intrabony defects, (II) studies providing outcomes of probing depth (PD) and clinical attachment loss (CAL). The literature searches and screening, data extraction, and quality assessment were performed by two reviewers, respectively. The Cochrane bias risk assessment tool was used to assess the quality of the literature. Meta-analysis was performed using Stata 15.0.

Results

A total of 8 randomized controlled trials (RCTs) were obtained, including 150 intrabony defect sites in the combination groups and 153 sites in the control groups. Meta-analysis showed that the combination groups was more effective than the control groups in PD [weighted mean difference (WMD) =-0.73, 95% confidence interval (CI): -0.94, -0.51, P=0.005], CAL (WMD =-0.56, 95% CI: -0.94, -0.19, P=0.003), and bone filling (BF) (WMD =-0.43, 95% CI: -0.65, -0.21, P=0.001), but the difference was not statistically significant between two groups in the change of gingival recession (REC) (WMD =-0.15, 95% CI: -0.44, 0.14, P=0.312). One study presented a high risk of bias due to lost follow-up, and the rest were unclear risk of bias.

Conclusions

For the treatment of periodontal intrabony defects, our meta-analysis showed that CGF combined with grafting materials was more effective than the use of grafting materials alone. However, the findings should be interpreted with caution due to the average quality of RCTs.

Histological examination of the effect of concentrated growth factor (CGF) on healing outcomes after maxillary sinus floor augmentation surgery

A double-blind clinical trial was conducted to examine the effect of concentrated growth factor (CGF), a new generation of platelet derivatives, on the healing outcome of maxillary sinus floor augmentation during maxillary sinus lift surgery. The study included 9 patients referred to the Tabriz University, Faculty of Dentistry, aged 30-80 years, with bilateral posterior partial edentulous or edentulous maxilla who underwent the procedure using a split-mouth technique. After lifting the Schneiderian membrane, bovine xenograft was randomly applied on one side (for example, left maxillary sinus) and CGF on the other side (for example, right maxillary sinus). Results from alizarin red and hematoxylin-eosin staining methods showed that the percentage of bone formed in the CGF group (112.41±26.34% and 96.16±24.49%, respectively) was significantly higher than in the control group (64.99±24.96% and 60.16±16.39%, respectively) (P<0.05). In addition, after 6 months, the amount of residual graft material in the control group (xenograft) was significantly higher than in the CGF group (P<0.05). These findings demonstrate that the use of CGF during open sinus lift surgery is reliable for the placement of dental implants.

Random and aligned electrostatically spun PLLA nanofibrous membranes enhance bone repair in mouse femur midshaft defects

Long-segment bone defects are a common clinical challenge and abstract biomaterials are a promising therapy. Poly-L-lactic acid (PLLA) nanofibrous membranes prepared by electrostatic spinning have a good bone repair potential. However, there are random and aligned surface morphologies of electrostatic spun PLLA nanofibrous membranes, which can affect the migration, proliferation, and differentiation ability of cells. The role of surface morphology in the repair of long bone defects in vivo is currently unknown. In this study, random and aligned electrostatically spun PLLA nanofibrous membranes were prepared, characterised, and implanted into a femur midshaft defect mouse model. The ability of electrostatically spun PLLA nanofibrous membranes to enhance bone repair was tested using X-ray photography, high-resolution micro-computed tomography (micro-CT), and pathological section specimens. The results showed that both random and aligned electrostatically spun PLLA nanofibrous membranes enhanced bone regeneration at bone defects, but the aligned ones exhibited superior results. These results provide a theoretical basis for engineering the surface morphology of bone repair materials.

Incidence and risk factors for surgical site infection following volar locking plating (VLP) of unstable distal radius fracture (DRF)

PURPOSE

Volar locking plating (VLP) is the mainstay of treatment for distal radius fracture (DRF) but may be compromised by postoperative surgical site infection (SSI). This study aimed to identify the incidence and the risk factors for SSI following VLP of DRF.

METHODS

This retrospective study identified consecutive patients who underwent VLP for closed unstable DRFs in our institution between January 2015 and June 2021. Postoperative SSI was identified by inquiring the medical records, the follow-up records or the readmission medical records for treatment of SSI. The potential factors for SSI were extracted from the medical records. Univariate and multivariate logistic regression analyses were performed to identify the independent factors.

RESULTS

There were 930 patients included, and 34 had an SSI, representing an incidence of 3.7% (95% CI 2.4-4.9%). Patients with an SSI had threefold extended hospitalization stay (44.1 ± 38.2 versus 14.4 ± 12.5 days) as did those without. In univariate analysis, 18 variables were tested to be statistically different between SSI and non-SSI group. In multivariate analysis, 6 factors were identified as independently associated with SSI, including sex (male vs. female, OR 3.5, p = 0.014), ASA (III and IV vs. I, OR 3.2, p = 0.031), smoking (yes vs. no, OR 2.4, p = 0.015), bone grafting (OR 4.0, p = 0.007), surgeon volume (low vs. high, OR 2.7, p 0.011) and operation at night-time (vs. day-time, OR 7.8, p < 0.001).

CONCLUSION

The postoperative SSI of VLP of DRF was not uncommon, and the factors identified in this study, especially those modifiable, would help identify individual SSI risk, target clinical surveillance and inform patient counseling.

Risk Factors for Complications following Volar Locking Plate (VLP) Fixation of Unstable Distal Radius Fracture (DRF)

Objective

To evaluate the incidence and risk factors for complications following volar locking plate (VLP) fixation of unstable distal radius fracture (DRF).

Methods

This retrospective study identified patients who underwent VLP fixation of unstable DRF between 2017 and 2020 with a minimum 12-month follow-up assessments. By reviewing electronic medical records and follow-up notes, patients were categorized complication or noncomplication group. Differences in variables were detected by using univariate analyses, and independent factors were identified using multivariate logistic regression analysis.

Results

During this study period, 423 patients were included, and 63 (rate, 14.9%) complications in 58 patients were documented. Wound infection (17, 4.0%) was most common, followed in decreasing frequency by carpal tunnel syndrome (13, 3.1%), tendon rupture/irritation (10, 2.4%), complex regional pain syndrome (8, 1.9%), and plate/screw-related complications (5, 1.7%). In the univariate analyses, 18 variables were found to be significantly different (p < 0.05). Logistic regression analysis identified 5 independent factors, including being male (OR, 3.5; p = 0.014), type C fracture (vs. type A, OR: 2.7, and p = 0.035), general anesthesia (vs. regional, OR: 2.4, and p = 0.045), bone grafting (OR, 6.3; p < 0.001), and surgery performed by less experienced surgeons (OR, 3.1; p = 0.003). The goodness-of-fit of the final model was acceptable.

Conclusions

These factors will help surgeons individualize and stratify the risk of complications and help patients for risk counselling; especially, an informed clinical decision targeting those modifiable factors (anesthesia mode, bone grafting, and surgeon experience) can be considered, when indicated.

Challenges and tissue engineering strategies of periodontal guided tissue regeneration

Periodontitis is a chronic infectious oral disease with a high prevalence rate in the world, and is a major cause of tooth loss. Nowadays, people have realized that the local microenvironment that includes proteins, cytokines, and extracellular matrix has a key influence on the functions of host immune cells and periodontal ligament stem cells during a chronic infectious disease such as periodontitis. The above pathological process of periodontitis will lead to a defect of periodontal tissues. Through the application of biomaterials, biological agents, and stem cells therapy, guided tissue regeneration (GTR) makes it possible to reconstruct healthy periodontal ligament tissue after local inflammation control. To date, substantial advances have been made in periodontal guided tissue regeneration. However, the process of periodontal remodeling experiences complex microenvironment changes, and currently periodontium regeneration still remains to be a challenging feat. In this review, we summarized the main challenges in each stage of periodontal regeneration, and try to put forward appropriate biomaterial treatment mechanisms or potential tissue engineering strategies that provide a theoretical basis for periodontal tissue engineering regeneration research.

Concentrated Growth Factors Promote hBMSCs Osteogenic Differentiation in a Co-Culture System With HUVECs

Osteogenesis is a complex physiologic process that occurs during bone regeneration. This process requires several growth factors that act on bone marrow-derived mesenchymal stem cells (BMSCs). Concentrated growth factor (CGF) is a new-generation platelet-rich derivative that is an appealing autologous material for application in tissue repair and bone regenerative medicine because it contains a variety of fibrin and growth factors. In this study, the effects of CGF on the proliferation and osteogenic differentiation of hBMSCs and human umbilical vein endothelial cells (HUVECs) were explored with in vitro cell co-culture experiments. HBMSCs and HUVECs were directly co-cultured at the ratio of 1:2 under different concentrations (0, 2, 5, 10, 20%) of CGF for 7 days. Alkaline phosphatase (ALP) staining and quantitative reverse transcription polymerase chain reaction were used to detect the effects of CGF on the expression of osteogenic genes (ALP, osteocalcin [OCN], type I collagen [COL-1], Runt-related transcription factor 2 [RUNX2]) and connexin 43 (CX43). RNA sequencing was used to explore potential regulated genes and signaling pathways that affect the osteogenesis of co-cultured hBMSCs exposed to CGF. The results showed higher expressions of ALP, COL-1, RUNX2, OCN, and CX43 in the direct co-culture group containing 10% CGF compared to the direct co-culture group without CGF and the indirect co-culture group. In summary, 10% CGF can significantly promote osteogenesis in hBMSCs directly co-cultured with HUVECs. Intercellular communication between the direct co-culture of hBMSCs and HUVECs through CX43 may be one of the main regulatory mechanisms.

Magnetostrictive alloys: Promising materials for biomedical applications

Magnetostrictive alloys have attracted increasing attention in biomedical applications because of the ability to generate reversible deformation in the presence of external magnetic fields. This review focuses on the advances in magnetostrictive alloys and their biomedical applications. The theories of magnetostriction are systematically summarized. The different types of magnetostrictive alloys and their preparation methods are also reviewed in detail. The magnetostrictive strains and phase compositions of typical magnetostrictive alloys, including iron based, rare-earth based and ferrite materials, are presented. Besides, a variety of approaches to preparing rods, blocks and films of magnetostriction materials, as well as the corresponding methods and setups for magnetostriction measurement, are summarized and discussed. Moreover, the interactions between magnetostrictive alloys and cells are analyzed and emphasis is placed on the transduction and transformation process of mechanochemical signals induced by magnetostriction. The latest applications of magnetostrictive alloys in remote microactuators, magnetic field sensors, wireless implantable devices and biodegradable implants are also reviewed. Furthermore, future research directions of magnetostrictive alloys are prospected with focus on their potential applications in remote cell actuation and bone repair.

Evaluation of the efficacy of concentrated growth factor along with bovine-derived xenograft and collagen membrane in the treatment of Degree II mandibular molar furcation defect – A clinicoradiographic study

Background:

The ultimate goal of furcation defect therapy is furcation closure via periodontal regeneration. However, the process of periodontal regeneration is affected by the regenerative environment of signaling molecules and growth factors due to which consistent findings of complete furcation closure could not be attained. In this study, we have evaluated the use of concentrated growth factor (CGF) which provides sustained release growth factors in conjunction with bovine-derived xenograft anorganic bovine bone (ABB) in guided tissue regeneration (GTR) of Degree II mandibular molar furcation defect.

Materials and Methods:

Twenty patients with Degree II mandibular molar furcation defects were selected for the study. Each group consisted of 10 patients and a total of 10 sites were treated in each group. The control sites were treated with GTR and ABB, while the experimental sites received CGF mixed with ABB along with GTR. Clinical parameters recorded were Plaque Index, Gingival Index, vertical probing depth, and horizontal probing depth measured at baseline and 6 months. Radiographic parameters such as the vertical height of defect, horizontal depth of defect, and percentage of vertical and horizontal bone fill were recorded at baseline and 6 months.

Results:

All the parameters recorded showed a significant reduction from baseline to 6 months in both the groups. Significantly higher vertical and horizontal bone fill was observed in the experimental group as compared to the control group.

Conclusion:

The use of CGF showed a positive additive efficacy in enhancing the events of periodontal regeneration in the treatment of Degree II mandibular molar furcation defect.

Mesenchymal stem cells prevent ovariectomy-induced osteoporosis formation in mice through intraosseous vascular remodeling

Mesenchymal stem cells (MSCs) can promote osteogenesis and are a promising therapy for postmenopausal osteoporosis. However, the relationship between improved intraosseous microcirculation and increased bone mass induced by MSCs in postmenopausal osteoporosis remains unclear. After the primary MSCs were characterized, they were transplanted into ovariectomized mice. MSCs transplantation enhanced the trabecular number, trabecular bone volume/total volume, and trabecular bone mineral density in ovariectomized mice. To determine the role of MSCs in vascular repair, mice were subjected to femoral artery ligation. Through laser speckle flowmetry, vascular perfusion and femoral trabecular bone and cortical bone analyses, we determined the effects of MSCs in promoting intraosseous angiogenesis and preventing osteoporosis in mice. MSCs effectively prevented postmenopausal osteoporosis development, which is associated with the involvement of MSCs in reestablishment of microcirculation within the skeleton.

The periosteum: a simple tissue with many faces, with special reference to the antler-lineage periostea

Periosteum is a thin membrane covering bone surfaces and consists of two layers: outer fibrous layer and inner cambium layer. Simple appearance of periosteum has belied its own complexity as a composite structure for physical bone protection, mechano-sensor for sensing mechanical loading, reservoir of biochemical molecules for initiating cascade signaling, niche of osteogenic cells for bone formation and repair, and "umbilical cord" for nourishing bone tissue. Periosteum-derived cells (PDCs) have stem cell attributes: self-renewal (no signs of senescence until 80 population doublings) and multipotency (differentiate into fibroblasts, osteoblasts, chondrocytes, adipocytes and skeletal myocytes). In this review, we summarized the currently available knowledge about periosteum and with special references to antler-lineage periostea, and demonstrated that although periosteum is a type of simple tissue in appearance, with multiple faces in functions; antler-lineage periostea add another dimension to the properties of somatic periostea: capable of initiation of ectopic organ formation upon transplantation and full mammalian organ regeneration when interacted with the covering skin. Very recently, we have translated this finding into other mammals, i.e. successfully induced partial regeneration of the amputated rat legs. We believe further refinement along this line would greatly benefit human health.

An evaluation of allogeneic freeze-dried concentrated growth factors biocompatibilityin vitroandin vivo

This study evaluated the biocompatibility of allogeneic freeze-dried concentrated growth factors (AFD-CGFs)in vitroandin vivo.For thein vitroexperiments, bone marrow stem cells (BMSCs) were cultured in 10% fresh allogeneic concentrated growth factors (CGFs). AFD-CGF solution was used as the experimental group, and Dulbecco's modified Eagle medium was used as control. Transmission electron microscopy (TEM) showed that the cell ultrastructure was unchanged, and membranes were intact. Scanning electron microscopy, cell counting kit-8, and quantitative polymerase chain reaction indicated that BMSCs and differentiation were unchanged between AFD-CGFs versus control groups (allp> 0.05). Alkaline phosphatase activity was higher in CGF groups (peaked at 14 d) than in the control group. Regarding thein vivoexperiments, four beagles were used for surgery and the rest as controls. Beagles were sacrificed at 2 weeks to observe acute response and membrane absorption; at 12 weeks for wound healing and chronic damage to the liver. According to general observations and histology, the CGFs of all groups were absorbed 2 weeks afterin vivoimplantation. No sign of intolerance was observed. Histology showed a slight increase in immune cells appearing in the implantation area after 2 weeks. However, no or very few inflammatory and immune cells were detected 3 months after the operation. Based on the hematoxylin and eosin staining and TEM results, the ultrastructure of the liver tissue was unchanged. In general, the results suggest that AFD-CGFs are biocompatible and may be a promising option for tissue healing.

Concentrated growth factor regulates the macrophage-mediated immune response

Concentrated growth factor (CGF) is a promising regenerative material that serves as a scaffold and adjunct growth factor for tissue engineering. The host immune response, particularly macrophage activity, plays a critical role in injury repair and tissue regeneration. However, the biological effect of CGF on the immune response is not clear. To enrich the theoretical groundwork for clinical application, the present study examined the immunoregulatory role of CGF in macrophage functional activities in vitro. The CGF scaffold appeared as a dense fibrin network with multiple embedded leukocytes and platelets, and it was biocompatible with macrophages. Concentrated bioactive factors in the CGF extract enhanced THP-1 monocyte recruitment and promoted the maturation of suspended monocytes into adherent macrophages. CGF extract also promoted THP-1 macrophage polarization toward the M2 phenotype with upregulated CD163 expression, as detected by cell morphology and surface marker expression. A cytokine antibody array showed that CGF extract exerted a regulatory effect on macrophage functional activities by reducing secretion of the inflammatory factor interleukin-1β while inducing expression of the chemokine regulated on activation, normal T cell expressed and secreted. Mechanistically, the AKT signaling pathway was activated, and an AKT inhibitor partially suppressed the immunomodulatory effect of CGF. Our findings reveal that CGF induces a favorable immune response mediated by macrophages, which represents a promising strategy for functional tissue regeneration.

CGF Membrane Promotes Periodontal Tissue Regeneration Mediated by hUCMSCs through Upregulating TAZ and Osteogenic Differentiation Genes

Concentrated growth factor (CGF) membranes are widely used in basic and clinical research of soft and hard tissue regeneration, but its effect on periodontal tissue regeneration is less studied. This study explored the role of CGF membranes in periodontal tissue regeneration mediated by human umbilical cord mesenchymal stem cells (hUCMSCs). HUCMSCs and human periodontal ligament fibroblasts (HPLFs) were extracted and identified by microscope and flow cytometry. The effects of the extracted CGF membrane on cell viability, osteogenic differentiation ability, osteopontin (OPN) expression, alkaline phosphatase (ALP) content, and osteogenic differentiation-related genes (Runt-related transcription factor 2 (RUNX2); osteocalcin (OCN); ALP), Tafazzin (TAZ) expression, and nuclear transfer were examined by MTT assay, alizarin red staining, immunofluorescence, enzyme-linked immunosorbent assay (ELISA), quantitative real-time polymerase chain reaction (qRT-PCR), and Western blot. Rescue experiments were performed to examine the effects of TAZ transfection and cell coculture. In the identified hUCMSCs (positive expressions of CD29, CD44, CD146, and CD105), overexpressed TAZ (pc-TAZ) enhanced the promotive effect of CGF membrane on cell viability, cell cycle, mineralization, ALP content and expressions of OPN, TAZ and osteogenic differentiation-related genes, and nuclear transfer. However, silencing TAZ showed opposite effects. The coculture of hUCMSCs and HPLFs further promoted the basic biological functions of HPLFs by upregulating osteogenic differentiation-related genes and COL-1 but downregulated MMP1 expression. Pc-TAZ could enhance the effect of CGF membrane on promoting periodontal tissue regeneration. CGF membrane promoted periodontal tissue regeneration through upregulating TAZ and osteogenic differentiation-related genes.

Promoting effect of rapamycin on osteogenic differentiation of maxillary sinus membrane stem cells

Background

Stem cells located in the maxillary sinus membrane can differentiate into osteocytes. Our study aimed to evaluate the effect of rapamycin (RAPA) on the osteogenic differentiation of maxillary sinus membrane stem cells (MSMSCs).

Methods

Colony-forming unit assay, immunophenotype identification assay, and multi-differentiation assay confirmed characteristics of MSMSCs obtained from SD rats. Transmission electron microscopy (TEM) and flow cytometry (FCM) identified the initial autophagic level of MSMSCs induced by RAPA. Real-time quantitative PCR (qPCR) evaluated subsequent autophagic levels and osteogenic differentiation. Alkaline phosphatase (ALP) activity assay and alizarin red staining (ARS) evaluated subsequent osteogenic differentiation. We performed a histological examination to clarify in vivo osteogenesis with ectopic bone mass from BALB/c nude mice.

Results

MSMSCs possessed an active proliferation and multi-differentiation capacity, showing a phenotype of mesenchymal stem cells. The autophagic level increased with increasing RAPA (0, 10, 100, 1,000 nM) and decreased over time. ALP activity and calcium nodules forming in four RAPA-treated groups on three-time points (7, 14, 21 d) showed significant differences. Col1a1, Runx2, and Spp1 expressed most in 100 nM RAPA group on 7 and 14 d. Osteogenesis-related genes except for Ibsp expression between four groups tended to be consistent on 21 d. 100 nM and 10 nM RAPA-treated groups showed more bone formation in vivo.

Conclusion

RAPA can promote osteogenic differentiation of MSMSCs, indicating a possible relationship between osteogenic differentiation and autophagy.

Use of PRP, PRF and CGF in Periodontal Regeneration and Facial Rejuvenation-A Narrative Review

Growth factors (GFs) play a vital role in cell proliferation, migration, differentiation and angiogenesis. Autologous platelet concentrates (APCs) which contain high levels of GFs make them especially suitable for periodontal regeneration and facial rejuvenation. The main generations of APCs presented are platelet-rich plasma (PRP), platelet-rich fibrin (PRF) and concentrated growth factor (CGF) techniques. The purpose of this review is to provide the clinician with an overview of APCs' evolution over the past decade in order to give reliable and useful information to be used in clinical work. This review summarizes the most interesting and novel articles published between 1997 and 2020. Electronic and manual searches were conducted in the following databases: Pubmed, Scopus, Cochrane Library and Embase. The following keywords were used: growth factors, VEGF, TGF-b1, PRP, PRF, CGF and periodontal regeneration and/or facial rejuvenation. A total of 73 articles were finally included. The review then addresses the uses of the three different techniques in the two disciplines, as well as the advantages and limitations of each technique. Overall, PRP is mainly used in cases of hard and soft tissue procedures, while PRF is used in gingival recession and the treatment of furcation and intrabony defects; CGF is mainly used in bone regeneration.

Application of a New Type of Natural Calcined Bone Repair Material Combined with Concentrated Growth Factors in Bone Regeneration in Rabbit Critical-Sized Calvarial Defect

Purpose

This study is aimed at investigating bone regeneration in critical-sized defects in rabbit calvarium using a novel nano- (n-) hydroxyapatite hybrid scaffold with concentrated growth factors (CGFs).

Methods

Twenty-four male adult rabbits were chosen to establish a critical-sized bone defect model and randomly divided into two groups. Two defects of 15 mm diameter each were created in the parietal bone of each animal. Group A had n-hydroxyapatite hybrid scaffold placed in the experimental defect on the right, and the left defect was unfilled as blank. Group B had hydroxyapatite hybrid scaffold mixed with CGF placed in the right defect and CGF on the left. Six animals in each group were sacrificed after 6 and 12 weeks. Cone-beam computed tomography system scanning and hematoxylin and eosin (HE) staining were used to detect osteogenesis within the defects.

Results

The treatment with n-hydroxyapatite hybrid scaffold along with CGF resulted in a significantly higher amount of new bone at 6 and 12 weeks compared to the treatment with CGF alone and the controls. No apparent inflammation and foreign body reaction were observed through HE staining.

Conclusions

The new synthesized n-hydroxyapatite hybrid scaffold and CGF can be applied for bone defect regeneration to promote the process to a certain extent.

Concentrated Growth Factors (CGF) Induce Osteogenic Differentiation in Human Bone Marrow Stem Cells

Bone regeneration is a complex process regulated by several factors that control overlapping biological processes, coordinating interactions among distinct cell populations. There is a great interest in identifying new strategies for inducing osteogenesis in a safe and efficient manner. Concentrated Growth Factor (CGF) is an autologous blood derived product obtained by centrifugation of venous blood following the procedure set on the Silfradent device. In this study the effects of CGF on osteogenic differentiation of human Bone Marrow Stem Cells (hBMSC) in vitro have been investigated; hBMSC were cultured with CGF or osteogenic medium, for 21 days. The osteogenic differentiation was evaluated measuring alkaline phosphatase (ALP) enzyme activity, matrix mineralization by alizarin red staining and through mRNA and protein quantification of osteogenic differentiation markers by Real-time PCR and Western blotting, respectively. The treatment with CGF stimulated ALP activity and promoted matrix mineralization compared to control and seems to be more effective than osteogenic medium. Also, hBMSC lost mesenchymal markers and showed other osteogenic features. Our study showed for the first time that CGF alone is able to induce osteogenic differentiation in hBMSC. The application of CGF on hBMSC osteoinduction might offer new clinical and biotechnological strategies in the tissue regeneration field.

Autologous Concentrated Growth Factors Combined with Topical Minoxidil for the Treatment of Male Androgenetic Alopecia: A Randomized Controlled Clinical Trial

Background: Minoxidil (MXD) is an U.S. Food and Drug Administration-approved drug for the topical treatment of androgenetic alopecia (AGA) with minor side effects, but its hair growth (HG) effect is unsatisfactory. Methods: A double-blinded within-subjects randomized clinical trial was conducted on 16 male AGA patients who showed limited improvement after MXD treatment. Eligible participants received three concentrated growth factor (CGF) injections on half of the scalp and the placebo on the other side at 4-week intervals, and MXD was applied twice daily on both sides throughout the follow-up period. The primary endpoint was the HG ratio at V4. The secondary endpoints included the HG ratios at V2, V3, and V5; hair density and T/V ratio at V2, V3, V4, and V5; Global Aesthetic Improvement Scale (GAIS) scores at V4 and V5; and participant satisfaction at V4. Results: Each group included 16 subjects; each half of the scalp was randomly assigned to the MXD+CGF or MXD group. The HG ratio at V4 was higher in the MXD+CGF group than in the MXD group. The MXD+CGF group had significant improvements in hair density, HG ratio, and T/V ratio compared with the MXD group over the follow-up period. The GAIS scores and participant satisfaction were higher in the MXD+CGF group than in the MXD group. Unexpectedly, the MXD+CGF treatment hastened HG, which was sustained for 3 months after discontinuation. No severe adverse events occurred. Conclusions: The combined treatment of MXD and CGF is safe and more efficient for AGA patients. Combining CGF can expedite the potency of MXD and provide patients with fast and lasting HG.

Concentrated growth factor inhibits UVA-induced photoaging in human dermal fibroblasts via the MAPK/AP-1 pathway

Ultraviolet (UV) radiation-induced photoaging is one of the contributors to skin aging. UV light triggers oxidative stress, producing a large number of matrix metalloproteinases (MMPs) and degrading the extracellular matrix in skin cells, thereby causing a series of photoaging symptoms. Concentrated growth factor (CGF) is a leukocyte- and platelet-rich fibrin biomaterial that plays a protective role in the occurrence and development of skin photoaging. In the present study, we investigated the underlying mechanism of CGF in the UVA-induced photoaging of human dermal fibroblasts (HDFs). A primary culture of HDFs was isolated from normal human facial skin. The cells were treated with CGF following UVA radiation. Proliferation of cells was detected using MTT assay, followed by measurement of reactive oxygen species (ROS) using immunofluorescence assay and flow cytometry. The mRNA and protein expression levels of P38, c-Jun, and MMP-1 were detected using real-time polymerase chain reaction and Western blot, respectively. CGF was found to improve cell viability by inhibiting the production of ROS and reducing oxidative damage. In addition, there was lower expression of p38 and c-Jun at the mRNA and protein levels following CGF treatment, thus resulting in the inhibition of MMP-1 expression. Our results suggest that CGF could protect HDFs against UVA-induced photoaging by blocking the P38 mitogen-activated protein kinase/activated protein-1 (P38MAPK/AP-1) signaling pathway. These findings provide a new clinical strategy for the prevention of skin photoaging.

In vitro and in vivo evaluation of the pH-neutral bioactive glass as high performance bone grafts

Osteogenic and angiogenic properties are two most valued factors for bone grafting materials. Biomedical materials with synergistic promotion effects on these two properties would be highly desirable. In this study, we showed that a recently developed pH-neutral bioactive glass (PSC) possessed such characteristics. Compared to two classical biomaterials, 45S5 bioactive glass and beta-tricalcium phosphate (β-TCP), PSC markedly improved BMSCs' proliferation, migration and mineralization as well as their osteogenic and angiogenic differentiation. In vivo, PSC showed better performance on inducing bone regeneration than both 45S5 and β-TCP, as featured by elevated bone mineral density (BMD) and new bone areas. PSC also significantly promoted new blood vessels formation compared with those in control groups. Furthermore, we revealed that PSC induced osteogenic and angiogenic differentiation of BMSCs through the PI3K/Akt/HIF-1α pathway, which had not been reported before. This synergistic effect of the PI3K/Akt/HIF-1α pathway on osteogenesis and angiogenic differentiation of BMSCs suggested that biomedical materials may promote new bone formation through multiple signal pathways, thus shedding light on the future development of materials with better performance.

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.

A compound of concentrated growth factor and periodontal ligament stem cell-derived conditioned medium

The aim of this study was to determine the in vitro effect of a compound of concentrated growth factor (CGF) and periodontal ligament stem cell-derived conditioned medium (PDLSCs-CM) as a potential product for future applications in periodontal tissue regeneration. Isolated PDLSCs were characterized using flow cytometry and differentiation into osteoblasts and adipocytes cells. PDLSCs-CM and CGF were prepared and lyophilized. To determine the optimal concentration of the CGF-CM compound, the proliferation of PDLSCs after exposure to a wide range of different concentrations of CGF, CM, or their combination (CGF + CM) was investigated by methyl thiazol tetrazolium assay. Successful isolation of PDLSCs was confirmed by high expression of mesenchymal surface markers and differentiation into osteoblasts and adipocytes. PDLSCs showed higher proliferation in the 6.25 mg/mL concentration of CM and 94 μg/mL concentration of CGF. High concentrations of CGF and CM markedly inhibited the proliferation of PDLCs (p < 0.05). The exposure of PDLSCs to the compound of 10% CM + 90% CGF significantly increased the cell proliferation (p < 0.05). The results showed that CGF, CM, or their combination exert a proliferative effect on cells at a certain concentration. Further investigation on the synergistic effect of this compound may approve its application for periodontal regeneration.

Astragalus saponin IV promotes osteogenic differentiation of bone marrow mesenchymal stem cells via miR-21/NGF/BMP2/Runx2 pathway

BACKGROUND

Astragalus saponin IV(AS- IV) extracted from tranditional Chinese medicine Radix Astragali Mongolici, which had been reported to have medicinal properties in treating several types of diseases. This study aimed at investigating the biological functions of AS-IV on bone marrow mesenchymal cells(BMSCs) differentiation, therefore, seeking for a better application of AS-IV on fracture or other orthopedic disorders.

METHODS

AS-IV was co-incubated with BMSCs in vitro to testify whether it can influence the proliferation and differentiation of BMSCs. Cell proliferation activity was detected by Cell Counting Kit-8 (CCK-8), while its differentiation promoting capibility was obtained by alkaline phosphatase (ALP) activity assay and Alizarin red S staining. Besides, differentiation protein markers of preosteoblast was detected by western blots. Neuron growth factor antagonists (NGFA) and microRNA-21 (miR-21) inhibitors were co incubated with AS-IV to search the regulatory pathways it activated in BMSCs.

RESULTS

AS-IV incubation boosted the proliferation of BMSCs, and accelerated the differentiating direction into preosteoblasts. Runx2, OPN, BMP2, OCN proteins were up regulated after AS- IV treatment. MiR-21/NGF/BMP2/Runx2 pathway can participate the biological effects of AS- IV on BMSCs.

CONCLUSION

AS- IV might be used as a therapeutic agent for bone fracture or other orthopedic disorders.

Allogenic Bone Graft Enriched by Periosteal Stem Cell and Growth Factors for Osteogenesis in Critical Size Bone Defect in Rabbit Model: Histopathological and Radiological Evaluation

Background & Objective:

This study aimed to investigate the effect of decellularized allogeneic bone graft enriched by periosteal stem cells (PSCs) and growth factors on the bone repair process in a rabbit model, which could be used in many orthopedic procedures.

Methods:

In this experimental study, a critical size defect (CSD) (10 mm) was created in the radial diaphysis of 40 rabbits. In group A, the defect was left intact with no medical intervention. In group B, the defect was filled by a decellularized bone graft. In group C, the defect was implanted by a decellularized bone graft enriched with platelet growth factors. In group D, the defect was treated by a decellularized bone graft seeded by periosteal mesenchymal stem cells (MSCs). Also, in group E, the defect was filled by a decellularized bone graft enriched with platelet growth factors and periosteal MSCs. Radiological evaluation was done on the first day and then in the second, fourth, and eighth weeks after the operation. The specimens were harvested on the 28th and 56th postoperative days and evaluated for histopathological criteria.

Results:

The radiologic and microscopic analysis of the healing process in bone defects of the treated groups (C, D, and E) revealed more advanced repair criteria than those of groups A and B significantly (P<0.05).

Conclusion:

Based on this study, it appears that implantation of concentrated PSCs in combination with growth factors and allogeneic cortical bone graft is an effective therapy for the repair of large bone defects.

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.

The Effect of Concentrated Growth Factor on Calvarial Bone in Diabetic Healing

The aim of this study was to evaluate the effect of Concentrated Growth Factor (CGF) on bone healing in diabetic rat model. Experimental diabetes was induced in 24 male Sprague-Dawley rats by streptozotocin. Twenty-four animals served as healthy controls. The animals were divided into 4 subgroups; empty bone defect, grafting with xenogenous graft (Geno-os, OsteoBiol, Turin-Italy), CGF administration, and combined application of the CGF with the xenogenous graft in critical-sized defects in the calvaria of the rats. The diabetic group was given 4 units of Neutral Protamin Hagedorn per day. After 6 weeks, all animals were sacrificed and bone healing was histologically and histomorphometrically analyzed, and the evaluation revealed that the new bone formation in diabetic animals was significantly lower than in healthy group (P: 0.001, P: 0.023). In both groups, the highest rate of ossification was observed in the combined use of xenogenous graft and CGF. When the new bone formation was examined in the graft and CGF group, no significant difference was found between control and diabetic group (P = 0.562; P > 0.05). In conclusion, in patients with diabetes mellitus, combination therapy of CGF with graft is expected to contribute positively to the healing of bone defect.

A novel approach to regenerate bone loss in an adolescent using concentrated growth factors: One-year follow-up

Destructive periodontal diseases are rare occurrences in the paediatric population. Moreover, the regenerative potential of the periodontal tissues and supporting structures of teeth is even rare, once irreversible damage has occurred. The aim of this paper is to discuss the regeneration of alveolar bone defect in a 14-year-old using concentrated growth factors (CGF). Following crown removal, scaling, debridement and site preparation, CGF was placed and secured in one-walled defect in the mesial side of the lower right permanent molar. The crown was replaced on to the tooth and the patient was followed up at 1, 3, 6, 9 and 12 months for clinical and radiographic evaluation. After 12 months, the radiographic evaluation revealed the defect to be filled with alveolar bone and probing pocket depth had reduced significantly. Thus, CGF can be an effective agent and can act as a potential scaffold for periodontal regeneration in adolescents with bone loss.

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.

Use of concentrate growth factors gel or membrane in chronic wound healing: Description of 18 cases

Treating chronic skin wounds in patients with diabetes, bed sores, or stasis dermatitis is typically a time-consuming and costly process, and the outcome is not always promising. Concentrated growth factor (CGF) obtained from the autologous venous blood of patients via fractional centrifugation is employed for producing a CGF gel or membrane that can be applied to expedite self-regeneration of skin wounds. In this case report, we presented the results from 18 patients with chronic skin wounds treated with a CGF gel or membrane produced from autologous venous blood. Noticeable granulation tissue and regenerated epidermal coverage were observed in 16 patients who received CGF treatment over various time courses, thereby demonstrating the significant therapeutic effects of CGF treatment in overall wound healing. The other two patients with stasis ulcers in their calves failed to respond to the treatment because of the comorbidity of iliac vein thrombosis. In addition, by culturing HaCaT keratinocytes using CGF membrane as the foundation, we observed that HaCaT cells attached to the CGF membrane migrated and proliferated to form an epithelium-like structure. Comprehensively, the clinical results infer that CGF gel can expedite the regeneration of the soft tissue at the wound, whereas CGF membrane may facilitate its marginal re-epithelialisation. The combination of the two can promote autologous regeneration of both deep and superficial wounds effectively and safely.

Local supplementation with plant-derived recombinant human FGF2 protein enhances bone formation in critical-sized calvarial defects

Numerous studies have demonstrated the advantages of plant cell suspension culture systems in producing bioactive recombinant human growth factors. This study investigated the biological activity of recombinant basic human fibroblast growth factor (rhFGF2) protein produced by a plant culture system to enhance new bone formation in a bone defect mouse model. The human FGF2 cDNA gene was cloned into a plant expression vector driven by the rice α-amylase 3D promoter. The vector was introduced into rice calli (Oryza sativa L. cv. Dongjin), and the clone with the highest expression of rhFGF2 was selected. Maximum accumulation of rhFGF2 protein (approximately 28 mg/l) was reached at 13 day post-incubation. Male C57BL/6 mice underwent calvarial defect surgery and the defects were loaded with absorbable collagen sponge (ACS) only (ACS group) or ACS impregnated with 5 μg of plant-derived rhFGF2 (p-FGF2) protein or E. coli-derived rhFGF2 (e-FGF2) protein. Similar to the effects of e-FGF2, local delivery with p-FGF2 enhanced bone healing in the damaged region to higher levels than the ACS group. Exogenous addition of p-FGF2 or e-FGF2 exhibited similar effects on proliferation, mineralization, and osteogenic marker expression in MC3T3-E1 cells. Together, the current findings support the usefulness of this plant-based expression system for the production of biologically active rhFGF2.

Concentrated growth factor promotes proliferation, osteogenic differentiation, and angiogenic potential of rabbit periosteum-derived cells in vitro

OBJECTIVE

The aim of this research is to investigate the effects of concentrated growth factor (CGF) on the proliferation, osteogenic differentiation, and angiogenic potential of rabbit periosteum-derived cells (PDCs) in vitro.

METHODS

PDCs were isolated from the femoral and tibial periosteum of rabbits and cultured with or without CGF membranes or CGF conditioned media. Scanning electron microscopy (SEM) was used for the structural characterization. Cell Counting Kit-8 assay was used to measure cell proliferation. Alkaline phosphatase (ALP) activity of PDCs was also measured. Immunohistochemistry was used to detect the expression of CD34. Enzyme-linked immunosorbent assay (ELISA), quantitative real-time PCR (qPCR), and Western blot were used to evaluate the secretion and expression levels of osteogenic differentiation markers (bone morphogenetic protein-2, type I collagen, osteocalcin) and angiogenesis markers (vascular endothelial growth factor, basic fibroblast growth factor) in supernatants and PDCs at days 3, 7, 14, and 21.

RESULTS

The SEM analysis showed a dense three-dimensional fibrin network in CGF, and CGF membranes were covered by PDCs with elongated or polygonal morphological features. Compared with the control group, CGF significantly promoted the proliferation of PDCs during the experimental period (p < 0.05). Immunohistochemistry revealed that PDCs were dispersedly distributed among the CGF substrates, and CD34-positive cells were also present. Moreover, CGF significantly increased the ALP activity and upregulated the expression and secretion of osteogenic differentiation and angiogenesis markers in PDCs at days 3, 7, 14, and 21 (p < 0.05).

CONCLUSION

CGF can increase the proliferation and promote the osteogenic differentiation and angiogenic potential of PDCs in vitro. These results indicate that CGF can be used as a new therapeutic means for biotechnological and clinical applications.