Novel applications of platelet concentrates in tissue regeneration (Review)

Evaluating the efficacy of platelet-rich plasma on orthodontic tooth movement rate: A systematic review and meta-analysis

BACKGROUND

The main objective of this study was to evaluate the effect of autologous platelet-rich plasma (PRP) on acceleration of the orthodontic tooth movement and assess the evidence based on the available literature.

METHODS

The trial was registered and reported according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Electronic databases including PubMed, Cochrane, Scopus, Central Register of Controlled Trials, and Google Scholar were searched for randomized controlled studies of PRP on the rate of tooth movement. The search was restricted to articles published in English between January 2000 to 31 December 2023. The search was completed by two reviewers independently and the risk of bias was evaluated using the Cochrane Risk of Bias tool (RoB 2.0) and meta-analysis was performed. Grading of Recommendations Assessment, Development, and Evaluation (GRADE) was done to determine the certainty of evidence.

RESULTS

Thirteen studies were included in the systematic review and 10 were included in the quantitative analysis. A random-effects model for meta-analysis of seven studies evaluating the rate of canine retraction revealed a statistically significant increase in the rate of orthodontic tooth movement of 0.38 mm/month in 1 month (121 patients; 95% confidence interval [CI] 0.27-0.49; I2 = 35%; P < 0.001) which decreased to 0.09mm/month in the fourth month (80 patients; 95% CI 0.02-0.17; I2 = 0%; P < 0.02). Three studies that considered en masse retraction revealed a mean difference of 0.36mm over 3 months (40 patients; 95% CI -0.23 to 0.94; I2 = 74%; P < 0.23).

CONCLUSIONS

The study suggests that PRP application can accelerate tooth movement, but its effects decreased over 4 months. The results should be interpreted cautiously due to the study's inherent limitations.

Platelet Power: Revitalizing Endodontics With Scaffolds

This article provides an overview of a biologically based method for restoring damaged tooth structures and pulp tissues known as regenerative endodontics. It explores the concept of regenerative endodontics, its tissue engineering approach, and its application in maintaining vitality. The article discusses the significance of the factors affecting growth, scaffolds, and stem cells being the three tissue engineering components involved in the regeneration of pulp tissues. It also delves into the classification of scaffolds and the role of platelet-rich fibrin (PRF) and platelet-rich plasma (PRP) as biological scaffolds. The methodology section details the search process for relevant studies, and the review section presents research findings associated with PRF and its application in regeneration and repair of tissue. The article concludes by highlighting the potential of advanced PRF and injectable PRF in regenerative endodontics, with a focus on their impact on tissue regeneration and healing.

What can we learn from treatments of oral lichen planus?

Oral lichen planus (OLP), a T-lymphocyte-mediated disease of the oral mucosa, has a complex pathogenesis that involves a number of factors. The disease is characterized by recurrent episodes and requires continuous follow up, and there is no curative treatment available. Erosive lichen planus, among others, has a risk of malignant transformation and requires standardized treatment to control its progression. Different clinical subtypes of oral lichen planus require appropriate treatment. Pharmacological treatments are the most widely available and have the greatest variety of options and a number of novel pharmacological treatments are presented as highlights, including JAK enzyme inhibitors. The second is photodynamic therapy, which is the leading physiological treatment. In addition, periodontal treatment and psychological treatment should not be neglected. In this review, we briefly discuss the most recent developments in therapies for oral lichen planus after summarizing the most widely used clinical treatments, aiming to provide different proposals for future clinical treatment.

Recent Achievements in the Development of Biomaterials Improved with Platelet Concentrates for Soft and Hard Tissue Engineering Applications

Platelet concentrates such as platelet-rich plasma, platelet-rich fibrin or concentrated growth factors are cost-effective autologous preparations containing various growth factors, including platelet-derived growth factor, transforming growth factor β, insulin-like growth factor 1 and vascular endothelial growth factor. For this reason, they are often used in regenerative medicine to treat wounds, nerve damage as well as cartilage and bone defects. Unfortunately, after administration, these preparations release growth factors very quickly, which lose their activity rapidly. As a consequence, this results in the need to repeat the therapy, which is associated with additional pain and discomfort for the patient. Recent research shows that combining platelet concentrates with biomaterials overcomes this problem because growth factors are released in a more sustainable manner. Moreover, this concept fits into the latest trends in tissue engineering, which include biomaterials, bioactive factors and cells. Therefore, this review presents the latest literature reports on the properties of biomaterials enriched with platelet concentrates for applications in skin, nerve, cartilage and bone tissue engineering.

The Potential of Autologous Platelet-Rich Plasma Gel for Diabetic Foot Ulcer Care Among Older Adults: A Systematic Review and Meta-Analysis

Introduction

Poorly controlled diabetes mellitus can lead to the development of diabetic foot ulcers (DFU), which is a frequent complication in patients. However, several diabetes management guidelines for older adults do not mention the occurrence of DFUs. Nowadays, Autologous Platelet-Rich Gel (APG) is being used for treating diabetic ulcers. APG is an innovative platelet-derived product with many advantages, such as being low-cost, easy to produce, and readily available materials. Additionally, it does not lead to any rejection reaction.

Objective

This study aims to assess the safety and efficacy of APG as a novel treatment of DFU compared with standard treatment in older adult patients.

Methods

Randomized Controlled Trials (RCTs) were searched using PubMed, Cochrane, Google Scholar, Wiley, and PlosOne. The keywords have been arranged using the Boolean operator, including autologous platelet-rich gel, DFU, and elderly. The data was screened by inclusion and exclusion criteria. The final inclusion study was analyzed and synthesized by tabulation, clusterization, contextual and thematic approach, and assessed for risk of bias using ROB 2.0. Meta-analysis was conducted by using Review Manager 5.4 and the Mantel Haenszel method.

Results

Eight RCTs with 598 patients were eligible for the present analysis. Compared with standard care/conventional treatment, APG could significantly improve the healing wound in patients with diabetic foot ulcers (Relative risk (RR) 1.32, 95% confidence interval (CI) 1.22-1.57, p < 0.0001), shortened the healing time (Mean difference [MD] -16.97 days (95% CI: -32.64 to -1.29; p < 0.00001), shortened the length of hospital stay (MD= -20.11, 95% CI: -38.02, -2.20; p = 0.03), and amputation rate (MD= 0.36, 95% CI: 0.16, 0.84; p = 0.02).

Conclusion

APG treatment can better treat DFU in terms of duration of healing, wound healing, length of hospital stay, and amputation prevention than the standard treatment.

The Potential Therapeutic Effects of Platelet-Derived Biomaterials on Osteoporosis: A Comprehensive Review of Current Evidence

Osteoporosis is a chronic multifactorial condition that affects the skeletal system, leading to the deterioration of bone microstructure and an increased risk of bone fracture. Platelet-derived biomaterials (PDBs), so-called platelet concentrates, such as platelet-rich plasma (PRP) and platelet-rich fibrin (PRF), have shown potential for improving bone healing by addressing microstructural impairment. While the administration of platelet concentrates has yielded positive results in bone regeneration, the optimal method for its administration in the clinical setting is still debatable. This comprehensive review aims to explore the systemic and local use of PRP/PRF for treating various bone defects and acute fractures in patients with osteoporosis. Furthermore, combining PRP/PRF with stem cells or osteoinductive and osteoconductive biomaterials has shown promise in restoring bone microstructural properties, treating bony defects, and improving implant osseointegration in osteoporotic animal models. Here, reviewing the results of in vitro and in vivo studies, this comprehensive evaluation provides a detailed mechanism for how platelet concentrates may support the healing process of osteoporotic bone fractures.

The Effectiveness of Autologous Platelet Concentrates in the Clinical and Radiographic Healing after Endodontic Surgery: A Systematic Review

Regenerative techniques are increasingly applied in endodontic surgery, but different materials may have varying impacts on soft and hard tissue healing. This systematic review aims to evaluate the effectiveness of autologous platelet concentrates (APCs) in clinical and radiographic healing after endodontic surgery. The data for this systematic review were processed following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines for improving the reporting of systematic reviews and meta-analyses. A literature search was conducted until October 2023 on PubMed, Scopus, and Cochrane Databases. Randomized controlled trials and controlled clinical trials addressing the use of APCs in patients who presented persistent periapical lesions and needed periapical surgery were included. Dual publications, narrative reviews, systematic reviews, case series, questionnaires, animal studies, case reports, letters to the editor, in vitro studies, and abstracts were excluded. In total, the search resulted in 14 papers. Clinical and radiographical findings were reported, showing that when APCs were used, patients exhibited less pain and swelling and a greater reduction of apical radiolucency after 12 months follow-up on average. However, the moderate/high risk of bias of included studies and their high heterogeneity, do not allow one to draw definitive conclusions on the effectiveness of APC after endodontic surgery.

Reinforcement of colon anastomosis healing with leukocyte platelet-rich fibrin in rabbit model

AIM

This study investigated the regenerative efficacy of leukocyte platelet-rich fibrin (L-PRF) on colon anastomotic healing in rabbits.

MAIN METHODS

Thirty-six healthy male white New Zealand rabbits were subjected to complete transactions of the ascending colon. The rabbits were equally divided into two groups: the control group, where the transected colon ends were anastomosed by a simple interrupted suture pattern, and the L-PRF-treated group, in which L-PRF was wrapped entirely around the anastomotic line. The postoperative acute pain scale was assessed using the Bristol Rabbit Pain Scale before surgery and at each four-hour interval post-operatively. After euthanizing the rabbits, the adhesion degree score, anastomotic bursting pressure, and stenosis degree of the anastomotic colon were assessed, and histopathological examination at the 7th, 14th, and 28th days postoperatively.

KEY FINDINGS

Rabbits in both groups showed a significant increase in pain scores compared to baseline. Postoperatively, the L-PRF group exhibited significantly lower pain scores, adhesion scores, and stenosis degrees than the control group. However, the anastomotic bursting pressure was significantly higher in the L-PRF group. Re-epithelialization, polymorphonuclear neutrophil infiltration, granulation tissue formation, and collagen deposition scores were improved considerably in the L-PRF group compared to the control group. Immunostaining of growth factor expression was significantly lower in the control than in the L-PRF group.

SIGNIFICANCE

The L-PRF can augment collagen deposition, re-epithelialize the mucosa, promote angiogenesis, reduce adhesions, and diminish the stenosis degree scores. Therefore, it can be considered a promising aid in healing bowel anastomoses.

Alginate-gelatin hydrogel supplemented with platelet concentrates can be used as bioinks for scaffold printing

Background

Owing to the growing global demand for organ replacement and tissue regeneration, three-dimensional (3D) printing is widely recognized as an essential technology in tissue engineering. Biomaterials become a potential source of raw materials for printing ink by containing factors that promote tissue regeneration. Platelet concentrates are autologous biological products that are capable of doing that.

Objectives

This study was carried out to create bioinks capable of providing biological signals by combining gelatin-alginate with platelet concentrates.

Methods

This study combined platelet concentrates, including platelet-rich plasma (PRP) and platelet-rich fibrin (PRF), with gelatin and alginate to create bioinks. Bioink properties, including gelatinization and pH, were assessed before printing. After that, the scaffolds were done, and the growth factor (GF) release and cytotoxicity from these scaffolds were performed.

Results

Results showed that all the three bioinks, including alginate-gelatin (AG), alginate-gelatin-PRP (AGP), and alginate-gelatin-PRF (AGF) were gelatinized right at the end of bioink fabrication and had a pH around 7. The scaffolds from bioinks supplemented with platelet concentrates secreted GFs that remained for 12 d, and the extracts from them were not cytotoxic for the L929 cell line.

Conclusion

In summary, bioinks were made by combining AG with platelet concentrates and had properties suitable for creating scaffolds with cell-oriented grafts in the development of artificial tissues and organs.

Healing effects of autologous platelet gel and growth factors on cutaneous leishmaniasis wounds in addition to antimony; a self-controlled clinical trial with randomized lesion assignment

OBJECTIVE

Autologous platelet gel (APG) is used in most surgeries to treat a variety of tissue defects because of its healing factors composition. This randomized parallel clinical trial was conducted to investigate the healing effects of APG on cutaneous leishmaniasis (CL) wounds. Eighteen male patients with CL wounds were recruited and followed for two months. The patients had more than one cutaneous wound, one of which was examined as the control and the other one as the intervention wound. APG was applied to the intervention wounds once a week, up to eight times. The primary endpoint was wound healing which defined as complete epithelialization and tissue granulation. Other clinical evaluation criteria were assessment of the wound size, and histopathology analyses.

RESULTS

Of 18 patients, 15 patients completed the trial (83.3%, mean age 28 years). The use of APG on the wounds was associated with complete and faster healing in 66% of the wounds and partial healing in 34% of the wounds. During the study, none of the control wounds were completely healed. The wound area in the intervention cases showed a statistically significant decrease throughout the study (P < 0.01) compared with controls. Following treatment of CL lesions with APG, the inflammatory process in the epidermis and dermis were decreased significantly (P < 0.01) compared with controls.

CONCLUSION

Our preliminary results confirm the clinical healing improvement described in the literature for APG-GF treatment of chronic non-leishmania wounds via immunomodulation.

TRIAL REGISTRATION

IRCT, IRCT20190212042694N1. Registered 20 February 2019, https://en.irct.ir/trial/37522.

Effect of platelet concentrates for pain and symptom management in oral lichen planus: an evidence-based systematic review

BACKGROUND

Platelet Concentrate (PC) injection therapy has shown potential as a local therapy for oral lichen planus (OLP). However, its safety and efficacy have not yet been fully established. Our research compared the efficacy of PC with topical steroid treatment in alleviating pain and symptoms related to OLP. We aims to present evidence-based alternatives that dentists can use to improve patient outcomes while reducing potential side effects.

METHODS

We conducted a systematic search of five electronic databases up to April 2023, including Embase, Cochrane Central Register of Controlled Trials, PubMed, OVID Medline, and WanFang, to evaluate PCs' efficacy compared to topical corticosteroid therapy for OLP. The literature quality was assessed using the Cochrane ROB tool. A fixed-effects model was used to determine the Weighted Mean Difference (WMD) and Mean Difference (MD) at a 95% confidence interval (CI) for pain severity and other relevant clinical indicators.

RESULTS

The comparison between topical corticosteroid therapy and PCs showed no significant difference for pain relief (WMD = -0.07, CI = 95% -0.34 to 0.19), symptom improvement (MD = -0.21, CI = 95% -0.55 to 0.13), or the severity of included lesions measured by REU scores (MD = -0.25, CI = 95% -0.32 to 0.82).

CONCLUSIONS

Locally injected PC have been found efficient in managing oral lichen planus, indicating that they are a promising alternative option to steroid therapy for OLP patients, particularly those who have not responded favorably to steroid therapy. However, further research is needed to establish determining the recurrence rate and long-term adverse effects.

TRIAL REGISTRATION

The systematic review protocol has been registered in advance with the PROSPERO database (CRD42023415372).

Autologous platelet-rich fibrin promotes wound healing in cats

Street cats commonly present large skin wounds that pose significant challenges in veterinary practice. Platelet-rich fibrin (PRF) is a second-generation platelet concentrate increasingly used in humans to promote wound healing. Ease of use and clinical success in humans has prompted interest in using PRF in veterinary practice. However, until now, there is no reported study on the use of autologous PRF in feline wound management. This study evaluated the effect of application of autologous PRF in cats with naturally occurring cutaneous wounds. 16 cats with full-thickness cutaneous acute/subacute wounds were randomly allocated to PRF or Control (standard care) groups. Each cat was enrolled for 2 weeks. PRF was prepared according to previously described procedures. PRF was applied on Days 1 and 4 in addition to standard wound care. Wound size was measured using tracing planimetry. Wound surface area was calculated using SketchAndCalc^™ software on scanned tracing images. Average wound sizes at enrolment were 8.39 cm² (Control) (standard deviation (SD) 5.08 cm²) and 9.18 cm² (PRF) (SD 3.71 cm²) (range 2.42-15.97 cm²). By Day 14, the mean wound size for the Control group was 2.17 cm² (SD 1.52 cm²) and for the PRF was 0.62 cm² (SD 0.44 cm²) (p = 0.015). At Day 14, the PRF group showed mean 93.85% wound contraction with SD 3.66, while the control group showed mean 76.23% wound contraction with SD 5.30 (p = <0.0001). Based on the results, PRF could be further investigated to promote wound healing in cats as a low-risk and convenient adjunctive therapy.

Injectable platelet-rich fibrin with demineralized freeze-dried bone allograft compared to demineralized freeze-dried bone allograft in intrabony defects of patients with stage-III periodontitis: a randomized controlled clinical trial

Aim

The current randomized controlled clinical trial assessed the effect of injectable platelet-rich fibrin (I-PRF) combined with demineralized freeze-dried bone allograft (DFDBA) compared to DFDBA alone in the management of intrabony defects of stage-III periodontitis patients.

Methodology

Following sample size calculation, twenty stage-III periodontitis patients with ≥ 5 mm clinical attachment level (CAL)-loss and ≥ 3 mm intrabony defects were randomized into test (I-PRF + DFDBA; n = 10) and control (DFDBA; n = 10) groups. CAL (primary outcome), periodontal probing depth (PPD), gingival recession depth (GRD), full-mouth plaque scores (FMPS), full-mouth bleeding scores (FMBS), radiographic linear defect depth (RLDD), and bone fill (secondary outcomes) were examined at baseline, 3, 6, and 9 months post-surgically.

Results

I-PRF + DFDBA and DFDBA independently demonstrated significant intragroup CAL-gain, PPD-, and RLDD-reduction at 3, 6, and 9 months (p < 0.05), with no significant intergroup differences observed (p > 0.05). CAL-gain (mean ± SD) of 2.40 ± 0.70 mm and 2.50 ± 0.85 mm and PPD-reduction of 3.50 ± 1.18 mm and 2.80 ± 0.42 mm were demonstrated for I-PRF + DFDBA and DFDBA at 9 months respectively. Both groups showed significant intragroup RLDD improvement, with a RLDD of 3.58 ± 0.66 mm and 3.89 ± 1.57 mm for I-PRF + DFDBA and DFDBA at 9 months respectively. Stepwise linear regression analysis revealed that baseline RLDD and bone fill at 9 months were significant predictors of CAL (p < 0.05).

Conclusion

Within the present study’s limitations, DFDBA with or without I-PRF resulted in significant improvement in clinical and radiographic periodontal parameters in the surgical treatment of periodontal intrabony defects of stage-III periodontitis patients. Addition of I-PRF to DFDBA does not appear to significantly enhance the DFDBA’s reparative/regenerative outcomes.

Clinical relevance

Within the current study’s limitations, routinely adding I-PRF to DFDBA cannot be recommended to significantly improve DFDBA’s treatment outcomes in intrabony defects.

Injectable Platelet-Rich Fibrin and Microneedling—A Non-Surgical Approach for Gingival Augmentation: A Randomized Controlled Clinical Trial

Aim:

The present study aimed to assess the efficacy of combining microneedling (MN) and injectable platelet-rich fibrin (i-PRF) administration with i-PRF alone in augmenting the thickness of gingiva to manage thin periodontal phenotype.

Methodology:

The clinical trial involved 36 patients who were diagnosed with thin periodontal phenotype. They were randomized under two groups: MN + i-PRF versus i-PRF alone, carried out as a split-mouth trial. One quadrant was treated only with i-PRF delivery through the gingival sulcus, while the contralateral side was treated with MN and i-PRF in 3 sessions at 10-day intervals. The primary parameter measured was the thickness of the gingiva, at baseline and 3 months following therapy. Statistical analysis was performed using the Mann-Whitney U test. Wilcoxon’s signed ranking test for inter-group and intra-group analysis, respectively.

Results:

The study results showed a significantly greater increase in gingival thickness (GT) in sites where both MN and i-PRF injection was done, compared to i-PRF alone, with a p value of .04.

Conclusion:

Both treatment modalities showed improvement in GT, being a minimally invasive alternative for mucogingival surgery. Adjunctive MN was found to be more beneficial than i-PRF alone. However, further research should be carried out to address the drawbacks of the study and for a better understanding of this novel approach.

Effect of local injection of injectable platelet-rich fibrin on eruption rate of teeth (Rabbit animal model)

OBJECTIVE

This study aimed to evaluate the effect of the local injection of injectable platelet-rich fibrin (i-PRF) on the eruption rate of the teeth and evaluation of the effect of i-PRF on the number of odontoblast, cementoblast, osteoblast, osteocyte, and osteoclast cells.

MATERIALS AND METHODS

The samples consisted of 20 male albino rabbits and were divided randomly into the control group (5 rabbits) and i-PRF groups (15 rabbits) sub-divided into week 1, week 2, and week 3 sub-groups. The labial surface of lower right incisors was marked by drilling a hole at the level of the free gingival margin in the mid-line of each tooth with a small round bur, and the eruption rates were measured by measuring the distance from the most apical point of the free gingival margin and the center of the hole with a digital caliper. i-PRF was prepared by centrifuging autologous blood of each rabbit at 1000 rpm for 5 minutes; then the i-PRF layer was collected. The control group received no treatment, whereas i-PRF groups received i-PRF in the following manner: For week 1 groups, a single dose was given at 0 day; for week 2 groups, double doses were given at 0 and 7 days; and for week 3 groups, three doses were given at 0, 7, and 14 days. At the end of experiments for each group, animal scarification was performed, and histological steps were performed.

RESULTS

There was a significant increase in the rate of tooth eruption in i-PRF groups when compared to the control group, and the eruption rate was increased in 107.3%, 144.7%, and 167.5% for week 1, week 2, and week 3, respectively. Concerning the histological finding, the i-PRF groups gave rise to a higher number of odontoblast, cementoblast, osteoblast, osteocyte, and osteoclast cells with a significant difference when compared to the control groups (P ≤ 0.05).

CONCLUSIONS

Applying i-PRF significantly increased the rate of teeth eruption at all-time intervals. Platelet-rich fibrin injection can be an effective method for acceleration of teeth eruption.

Enhanced Bioactive Potential of Functionalized Injectable Platelet-Rich Plasma

Injectable platelet-rich fibrin (iPRF) is a frequently used platelet concentrate used for various medical purposes both in veterinary and human medicine due to the regenerative potential of hard and soft tissues, and also because of its antimicrobial effectiveness. This in vitro study was carried out to assess the cumulative antimicrobial and antibiofilm effect of iPRF functionalized with a multifunctional glycoprotein, human lactoferrin (Lf). Thus, the ability to potentiate cell proliferation was tested on keratinocytes and evaluated by the CCK8 test. The combinations of iPRF and Lf induced an increase in the proliferation rate after 24 h. The average cell viability of treated cultures (all nine variants) was 102.87% ± 1.00, and the growth tendency was maintained even at 48 h. The highest proliferation rate was observed in cultures treated with 7% iPRF in combination with 50 µg/mL of Lf, with an average viability of 102.40% ± 0.80. The antibacterial and antibiofilm activity of iPRF, of human lactoferrin and their combination were tested by agar-well diffusion (Kirby-Bauer assay), broth microdilution, and crystal violet assay against five reference bacterial strains. iPRF showed antimicrobial and antibiofilm potential, but with variations depending on the tested bacterial strain. The global analysis of the results indicates an increased antimicrobial potential at the highest concentration of Lf mixed with iPRF. The study findings confirmed the hypothesized enhanced bioactive properties of functionalized iPRF against both Gram-positive and Gram-negative biofilm-producing bacteria. These findings could be further applied, but additional studies are needed to evaluate the mechanisms that are involved in these specific bioactive properties.

Concentrated Growth Factors Combined with Lipopolysaccharide Stimulate the In Vitro Regenerative and Osteogenic Activities of Human Dental Pulp Stem Cells by Balancing Inflammation

Aim

We investigated the long-term effects of exposure to concentrated growth factors (CGFs) on the regenerative properties of dental pulp stem cells (DPSCs) in the presence and absence of lipopolysaccharide (LPS) as a proinflammatory agent.

Methods

DPSCs were cultured with CGF at different concentrations of LPS (0.1, 1, and 10 µg/ml) for 21 days. Then, using MTT and scratch assays, the cell viability and migration were examined. Osteogenic stimulation was evaluated by alkaline phosphatase (ALP) staining and Sirius Red staining, which determined the ALP activity and collagen levels, respectively. The expression levels of osteogenic markers were quantified using the qRT-PCR method. One-way analysis of variance (ANOVA) and Tukey's HSD test were used to analyze differences between groups.

Results

Long-term treatment of DPSCs with CGFs reduced LPS-induced cell death. Moreover, CGF and LPS (1 µg/ml), either in combination or alone, improved the DPSC migratory ability and caused a significant increase in osteogenic stimulation through the upregulation of collagen levels and ALP activity. Additionally, CGFs significantly upregulated RUNX2, DSPP, OCN, and OPN mRNA levels (as osteogenic markers), while LPS (1 µg/ml) only significantly increased OCN overexpression.

Conclusion

Our findings are evidence that CGF could be a promising agent to induce dentin-pulp complex healing in long-term chronic inflammation.

Use of CGF in Oral and Implant Surgery: From Laboratory Evidence to Clinical Evaluation

Edentulism is the condition of having lost natural teeth, and has serious social, psychological, and emotional consequences. The need for implant services in edentulous patients has dramatically increased during the last decades. In this study, the effects of concentrated growth factor (CGF), an autologous blood-derived biomaterial, in improving the process of osseointegration of dental implants have been evaluated. Here, permeation of dental implants with CGF has been obtained by using a Round up device. These CGF-coated dental implants retained a complex internal structure capable of releasing growth factors (VEGF, TGF-β1, and BMP-2) and matrix metalloproteinases (MMP-2 and MMP-9) over time. The CGF-permeated implants induced the osteogenic differentiation of human bone marrow stem cells (hBMSC) as confirmed by matrix mineralization and the expression of osteogenic differentiation markers. Moreover, CGF provided dental implants with a biocompatible and biologically active surface that significantly improved adhesion of endothelial cells on CGF-coated implants compared to control implants (without CGF). Finally, data obtained from surgical interventions with CGF-permeated dental implants presented better results in terms of optimal osseointegration and reduced post-surgical complications. These data, taken together, highlight new and interesting perspectives in the use of CGF in the dental implantology field to improve osseointegration and promote the healing process.

In Vitro and Ex Vivo Kinetic Release Profile of Growth Factors and Cytokines from Leucocyte- and Platelet-Rich Fibrin (L-PRF) Preparations

L-PRF is an autologous blood-derived biomaterial (ABDB) capable of releasing biologically active agents to promote healing. Little is known about its release profile of growth factors (GFs), cytokines, and MMPs. This study reported the in vitro and ex vivo release kinetics of GFs, cytokines, and MMPs from L-PRF at 6, 24, 72, and 168 h. The in vitro release rates of PDGF, TGF-β1, EGF, FGF-2, VEGF, and MMPs decreased over time with different rates, while those of IL-1β, IL-6, TNF-α, IL-8, and IL-10 were low at 6 h and then increased rapidly for up to 24 h and subsequently decreased. Of note, the release rates of the GFs followed first-order kinetics both in vitro and ex vivo. Higher rates of release were found ex vivo, suggesting that significant amounts of GFs were produced by the local cells within the wound. In addition, the half-life times of GFs locally produced in the wound, including PDGF-AA, PDGF-AB/BB, and VEGF, were significantly extended (p < 0.05). This work demonstrates that L-PRF can sustain the release of GFs and cytokines for up to 7 days, and it shows that the former can activate cells to produce additional mediators and amplify the communication network for optimizing the wound environment, thereby enhancing healing.

Biodegradable Microparticles for Regenerative Medicine: A State of the Art and Trends to Clinical Application

Tissue engineering and cell therapy are very attractive in terms of potential applications but remain quite challenging regarding the clinical aspects. Amongst the different strategies proposed to facilitate their implementation in clinical practices, biodegradable microparticles have shown promising outcomes with several advantages and potentialities. This critical review aims to establish a survey of the most relevant materials and processing techniques to prepare these micro vehicles. Special attention will be paid to their main potential applications, considering the regulatory constraints and the relative easiness to implement their production at an industrial level to better evaluate their application in clinical practices.

Efficacy of concentrated growth factor with low-level laser for the regeneration of interdental papilla defects

Gingival "black triangle" is common in clinical which due to interdental papilla recession. The cause of the loss of papilla is multi-factorial and it may be caused by the absorption of interdental alveolar bone or abnormal tooth position. Besides, it is a common complication after orthodontics and implant surgery. Recession of gingival papilla influences interdental plaque control, increasing food impaction and alveolar bone absorption, causing aesthetic and pronunciation problems. Thus, the way of reducing or eliminating the gingival "black triangle" has become one of the most essential problems for dentists. Concentrated growth factor (CGF) and low-level-laser therapy have been widely used, respectively, and CGF was considered as the only self-substance which has soft tissue regeneration function. This study aims to evaluate the efficacy of regenerating interdental papilla by Liquid phase concentrated growth factor (LPCGF) injection with low-level-laser therapy (LLLT).

The adjunctive effect of autologous platelet concentrates on orthodontic tooth movement: A systematic review and meta-analysis of current randomized controlled trials

OBJECTIVE

To evaluate the effectiveness of autologous platelet concentrates (APCs) as adjuncts on accelerating orthodontic tooth movement (OTM) of the human subjects undergoing orthodontic treatment and to critically appraise the available literature.

METHODS AND MATERIALS

Five electronic databases (PubMed, Scopus, Web of Science, Embase, and Cochrane Central Register of Controlled Trials) were searched from 2000 up to May 2021 to retrieve eligible randomized controlled trials (RCTs) investigating patients who underwent orthodontic treatment that involved OTM of maxillary and mandibular incisors and canines. All the enrolled cases were treated with APCs and had no local or systemic interfering factors. The quality of the included studies was assessed using the modified JADAD scale. The effect sizes were assessed using mean difference (MD). The heterogeneity analysis was conducted using (I²) statistic at α=0.10.

RESULTS

Finally, seven RCTs were included in the qualitative, and two RCTs were included in the quantitative analysis. The meta-analysis was performed regarding the effect of injectable platelet-rich fibrin (I-PRF) on the rate of canine tooth movement in millimeters at different intervals of the 1^st, 2^nd, and 3^rd months. In the 1^st month, I-PRF (WMD:0.12mm, CI95% -5.01 to 5.24, I²=90%) did not significantly affect OTM. In the 2^nd month, I-PRF (WMD:0.66mm, CI95% 0.60 to 0.73, I²=10%) significantly increased the OTM. However, in the 3^rd month, I-PRF did not significantly increase the OTM (WMD:0.54mm, CI95% -1.38 to 2.47, I²=67%).

CONCLUSIONS

According to the low certainty of evidence about this topic, providing a definite conclusion is not possible. However, applying I-PRF seems to be efficient in accelerating the OTM of the canines. Further high-quality studies with larger sample sizes will be indispensable to validate this conclusion.

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.

AIRMESS - Academy of International Regenerative Medicine & Surgery Societies: recommendations in the use of platelet-rich plasma (PRP), autologous stem cell-based therapy (ASC-BT) in androgenetic alopecia and wound healing

INTRODUCTION

Many investigations showed that platelet-rich plasma (PRP), human follicles stem cells (HFSCs), and adipose-derived stem cells (ASCs), considered autologous stem cell-based therapy (ASC-BT), are effective for hair regrowth (HR) in patients affected by androgenetic alopecia and for wound healing (WH). The aim of this article is to analyze the in vitro and in vivo impact of different PRP, HFSCs, and ASCs preparation methods on HR and in WH.

AREAS COVERED

The analyzed data intended to clarify the molecular mechanism in which PRP, HFSCs, and ASCs are involved, the clinical use and related indications, fully respecting the European rules. Comparative studies between different systems of PRP, HFSCs, and ASCs preparation revealed differences in terms of HR and WH.

EXPERT OPINION

Despite a lack of standardized protocols, there is convincing evidence with objective measurement modalities that display positive outcomes of ASC-BT in HR and WH.