Antibacterial effect of plasma rich in growth factors (PRGF®-Endoret®) against Staphylococcus aureus and Staphylococcus epidermidis strains

Use of regenerative medicine in the treatment of endometritis in mares: A systematic review and meta-analysis

Defining the optimal therapy for endometritis remains a significant challenge for clinicians. Given the public health threat posed by antibiotic resistance and the inconclusiveness of traditional therapies, regenerative medicine has been proposed as an alternative. The objective of this study was to conduct a comprehensive systematic review and meta-analysis, to investigate the efficacy of regenerative medicine products in the treatment of both post-breeding persistent and chronic degenerative endometritis (PBIE/CDE) in mares, following the PRISMA guidelines. This research could be a comprehensive scientific reference for determining appropriate treatments and clinical strategies. All studies exploring the use of regenerative medicine therapies (i.e., plasma products, autologous conditioned serum, mesenchymal stem cells MSCs, and MSC derivatives) in the treatment of PBIE/CDE were included, regardless of the specific protocol used, the evaluated outcomes, or the diagnostic method employed. Two authors independently gathered data and evaluated the risk of bias for each study. Treatment effects were assessed using risk ratios for dichotomous data, accompanied by 95 % confidence intervals. Data were aggregated utilizing the fixed-effects model. The quality of evidence for each outcome was evaluated using GRADE criteria. Eighteen studies were included in the systematic review, while fifteen trials were included in the meta-analysis. A sub-meta-analysis was conducted separately on platelet-derived products, as well as on MSCs and their derivatives. The results demonstrated an overall positive effect of regenerative therapies in treating PBIE/CDE, particularly those involving MSCs and their derivatives. The positive outcomes include an anti-inflammatory effect, characterized by reduced intrauterine fluid accumulation, neutrophils, and cytokine concentrations. Additionally, improvements in pregnancy, foaling, and embryo recovery rates have been observed in some cases. Despite the limited number of randomized controlled studies and the high variability among protocols, including the timing of treatment, type, and volume of products used, the use of regenerative products, especially MSCs and their derivatives, has promising results in terms of both efficacy and safety for treating PBIE/CDE in mares.

How to explain the beneficial effects of leukocyte- and platelet-rich fibrin

The survival of an organism relies on its ability to repair the damage caused by trauma, toxic agents, and inflammation. This process involving cell proliferation and differentiation is driven by several growth factors and is critically dependent on the organization of the extracellular matrix. Since autologous platelet concentrates (APCs) are fibrin matrices in which cells, growth factors, and cytokines are trapped and delivered over time, they are able to influence that response at different levels. The present review thoroughly describes the molecular components present in one of these APCs, leukocyte- and platelet-rich fibrin (L-PRF), and summarizes the level of evidence regarding the influence of L-PRF on anti-inflammatory reactions, analgesia, hemostasis, antimicrobial capacity, and its biological mechanisms on bone/soft tissue regeneration.

Effects of plasma rich in growth factors on wound healing in patients with venous ulcers

Introduction

Significant evidence suggests that plasma-rich in growth factors (PRGF) favor the repair of chronic wounds, enabling a rapid return to functionality. However, components of PRGF and their effects on persistent ulcers and epithelial tissues are not well characterized. The goals of this research were to analyze the biological properties of platelet-derived factors, to examine their effectiveness on healing of venous ulcers, and to establish a correlation with clinical and sociodemographic data.

Methods

For the preparation of PRGF, the centrifugation technique was used, obtaining a 100 % autologous and biocompatible blood sample that was treated with sodium citrate and calcium chloride. The patients were attended weekly at the outpatient clinic for nursing consultation and wound dressing changes, with PRGF application every 15 days. The treatment protocols are described, and follow-up results are reported.

Results

Initially, the patients' ulcers ranged in sizes from 4 to 84 cm2. After 12 weeks of treatment, there was a significant mean reduction of 46.2 % in ulcer area. At baseline, epithelial tissue was absent in all venous ulcers, but its presence grew significantly by the treatment period. However, the reduction of the area of the ulcers did not show significant correlation with the concentrations of the patient's growth factors.

Conclusions

Using the established protocol for PRGF isolating, it was possible to obtain a product with the presence of the six growth factors related to tissue regeneration and observed a positive response on wound healing following treatment of venous ulcers, with capacity to accelerate re-epithelialization and restore the skin functional integrity.

In Vitro Antimicrobial Properties and Their Mechanisms in Relation to Reactive Oxygen Species of Canine Platelet-Rich Fibrin

Platelet-rich fibrin (PRF), which has been shown to promote wound and bone regeneration, has demonstrated antimicrobial properties against periodontal pathogens. However, in veterinary medicine, no study has determined the antimicrobial effects of canine platelet-rich fibrin (cPRF). Therefore, this study aimed to determine the antimicrobial effect of cPRF against E. coli and S. pseudintermedius found in dogs' wounds and against the standard strain S. aureus. Additionally, the mechanism of the existing antibacterial activity of cPRF, which involves the formation of reactive oxygen species (ROS), was tested. Blood samples from six dogs were processed for cPRF. The antimicrobial properties of three groups (growth control, cPRF, and drug control) were evaluated at 0.5, 4, 8, and 24 h using a time-kill assay. The killing mechanisms involving ROS were evaluated using horseradish peroxidase (HRP) to suppress ROS production in PRF (PRF-SR). Subsequently, tests for antimicrobial properties and ROS generation were compared to those of the growth control and cPRF groups. The results showed that cPRF had significant antimicrobial properties against E. coli but no antimicrobial properties against S. pseudintermedius. After the ROS suppression, PRF-SR did not show an antimicrobial property against E. coli. Moreover, cPRF-treated bacteria exhibited significantly greater intracellular ROS than PRF-SR. In conclusion, canine PRF showed an antimicrobial effect against E. coli, and its antibacterial mechanism was related to releasing ROS.

Antimicrobial Activity of Plasma Rich in Platelets (PRP) on the Ocular Microbiota of Healthy Horses from Minas Gerais: In Vitro Study

In equine ophthalmology, ulcerative keratitis is among the most common conditions and, in general, arises as a consequence of some trauma suffered. Secondarily, subsequent contamination by pathogenic or resident bacteria of the horse's ocular microbiota may have undesirable consequences. Under physiological conditions, the normal microbiota coexists with the immune status of the host, serving as a barrier, ensuring the health of the ocular surface, and inhibiting the proliferation of pathogens. However, in the imbalance of immune barriers, the normal microbiota can become pathogenic and lead to infection, acting as an opportunistic agent. The present study aims to demonstrate the antimicrobial effect of platelet-rich plasma (PRP), its time of action, and its correlation with the concentration of its same components in vitro on Staphylococcus sciuri, a bacterium with high prevalence in the normal ocular microbiota of horses in the municipality of Minas Gerais. For the preparation of the PRP, eight adult Quarter Horse (QH) horses were used. The individual PRP was prepared by the double centrifugation protocol, and then, the PRPs were added to a pool, followed by testing their interaction in culture with Brain Heart Infusion (BHI) broth at different dilutions against five strains collected from different animals. After 3, 6, 12, and 18 hours, the colony formation units (CFU) count on a 5% horse blood agar plate was evaluated for each time point. Our study showed that Staphylococcus sciuri, the resident microorganism of the ocular conjunctival microbiota of horses, is more susceptible when compared to the standard strain "American Type Culture Collection" (ATCC-29213) Staphylococcus aureus, a pathogenic microorganism, which was used for the validation of our study. The antibacterial effect shown in this study was bacteriostatic for up to 6 hours. The most concentrated PRP dilutions, 1 : 1 and 1 : 2, were also most effective, suggesting that the antibacterial effect is volume dependent.

Adjunctive Plasma Rich in Growth Factors in the Treatment of Osteomyelitis and Large Odontogenic Cysts Prior to Successful Implant Rehabilitation: Case Report

Osteomyelitis of the jaws presents a clinical challenge to conventional treatment, often requiring multiple surgical interventions resulting in significant deformity and presenting significant problems to satisfactory rehabilitation. While benign odontogenic cysts, such as the radicular cyst, are generally predictably treated, they can cause significant localized bone destruction and thus can present significant problems in satisfactory rehabilitation. In this case report, patients were treated combining conventionally appropriate surgical debridement and oral antibiotics with adjunctive plasma rich in growth factors (PRGF). Patients showed a complete soft tissue and osseous regeneration to their pre-pathologic state, with successful implant rehabilitation. PRGF appears to be highly successful in minimizing or eliminating osseous deformities normally associated with conventional treatment of osteomyelitis of the jaw and treatment of large odontogenic cysts. Future trials must be performed to confirm these results in comparison to controls using conventional treatment alone.

Effect of advanced and injectable platelet-rich fibrins against Aggregatibacter actinomycetemcomitans in subjects with or without periodontal diseases

Background/purpose: Data for comparing effects of advanced platelet-rich fibrin (A-PRF+) and injectable platelet-rich fibrin (i-PRF) against Aggregatibacter actinomycetemcomitans (Aa) in subjects with differently periodontal conditions are scarce. This study aimed to compare the antimicrobial capacity of A-PRF+ and i-PRF obtained from subjects with or without periodontal diseases against the pathogenic bacteria Aa.

Materials and methods

The number of red blood cells, platelets, and white blood cells on the blood samples of 60 individuals, including healthy subjects (n = 20), patients with gingivitis (n = 20), and patients with periodontitis (n = 20), were analyzed before preparing A-PRF+ and i-PRF. In addition, the in vitro antibacterial effect of the two platelet concentrates was evaluated by using the agar diffusion test and a minimum inhibitory concentration (MIC) experiment.

Results

I-PRF exhibited a significantly better antibacterial effect than A-PRF+ within the gingivitis and periodontitis groups, with a more expansive zone of inhibition and a lower MIC. Among the studied groups, the A-PRF+ and i-PRF collected from the periodontitis group inhibited Aa significantly more compared with the gingivitis and healthy groups.

Conclusion

Although both A-PRF+ and i-PRF exhibited an antibacterial effect against Aa through the zone of inhibition and MIC tests, in the gingivitis and periodontitis groups, i-PRF exhibited better antibacterial activity than A-PRF+, and PRF products from the periodontitis group had greater effects against Aa than PRF products from the two other groups.

Stem cell and tissue engineering approaches in pressure ulcer treatment

CONTEXT

Pressure ulcers or injuries, arise from ischemic damage to soft tissues induced by unrelieved pressure over a bony prominence. They are usually difficult to treat with standard medical therapy and often they recur. In the search for better treatment options, promising alternative forms of treatment are today emerging. Within the field of regenerative medicine, ongoing research on advanced therapies seeks to develop medicinal products based on gene therapy, somatic cell therapy, tissue-engineering and combinations of these.

OBJECTIVE

The main objective is to perform an overview of experimental and clinical developments in somatic cell therapy and tissue engineering targeting the treatment of pressure injuries.

METHODS

Searching terms as "PRESSURE ULCER", "STEM CELL THERAPY", "TISSUE ENGINEERING" or "WOUND HEALING" were used in combination or alone, including publications refered to basic and clinical research and focusing on articles showing results obtained in a clinical context. A total of 80 references are cited, including 23 references published in the 3 last years.

RESULTS

The results suggest that this form of treatment could be an interesting option in patients with difficult-to-treat ulcers as spinal cord injury patients.

CONCLUSION

This field of regenerative medicine is very broad and further research is warranted.

Antimicrobial effect against Aggregatibacter actinomycetemcomitans of advanced and injectable platelet-rich fibrin from patients with periodontal diseases versus periodontally healthy subjects

Objectives

Advanced platelet-rich fibrin (A-PRF+) and injectable platelet-rich fibrin (i-PRF) have recently been developed and used in periodontal therapy. Few studies have contrasted the antibacterial effectiveness of these autologous materials derived from individuals with healthy gums, gingivitis, and periodontitis. This study aimed to compare the antimicrobial effects of these PRF materials against the periodontal pathogenic bacterium Aggregatibacter actinomycetemcomitans (Aa) in patients with different periodontal conditions.

Methods

Blood samples were collected from periodontally healthy individuals, patients with gingivitis, or patients with periodontitis to prepare A-PRF+ and i-PRF. The antibacterial capacity of these materials was evaluated through antibiofilm formation, biofilm susceptibility, and the time-kill assay over a 48-h period.

Results

A-PRF+ and i-PRF from each patient groups interfered with Aa's ability to form biofilm on the test tube surface, and the effect of i-PRF was significantly different among the patient groups. In contrast, these plasma preparation had a weak impact on mature biofilm. For products from the gingivitis and periodontitis groups, these effects were significantly stronger for i-PRF than A-PRF+ (p = 0.012 and p = 0.004, respectively). All plasma preparations inhibited Aa growth in the first 12 h after application, and i-PRF exhibited a significantly greater antimicrobial effect than A-PRF + at each time point.

Conclusion

A-PRF+ and i-PRF in all three patient groups could inhibit the growth of Aa in vitro, and i-PRF from patients with periodontitis exhibited a more significant effect than PRF from the other groups.

High-Throughput Proteomic Analysis of Human Dermal Fibroblast Response to Different Blood Derivatives: Autologous Topical Serum Derived from Plasma Rich in Growth Factors (PRGF) versus Leukocyte- and Platelet-Rich Plasma (L-PRP)

Platelet-rich plasma (PRP) is nowadays used in the treatment of different types of cutaneous lesions. However, different compositions can influence clinical outcomes. Among them, the inclusion of leukocytes is controversial. High-throughput proteomics techniques were used to analyze the proteins that are differentially expressed in human dermal fibroblasts (HDFs) after treatment for 24 h with two PRP types, autologous topical serum (Endoret serum—ES) derived from plasma rich in growth factors (PRGF) and leukocyte- and platelet-rich plasma (L-PRP). The identified proteins were then classified by both Gene Ontology and Ingenuity Pathway Analysis. The obtained results show that the compositions of ES and L-PRP differ in such a way that they induce different responses in HDFs. ES-treated HDFs overexpress growth factor-related proteins, leading to protein synthesis, cell proliferation and migration. By contrast, L-PRP treatment induces a response similar to that caused by proinflammatory molecules. These data could explain the contradictory clinical results obtained for the different types of PRP, especially with respect to their leukocyte contents.

Comparison effects of platelet-rich plasma on healing of infected and non-infected excision wounds by the modulation of the expression of inflammatory mediators: experimental research

INTRODUCTION

Microbial invasion in soft tissue is believed to cause infectious wounds and increase healthcare costs, anxiety, and distress. The current study was conducted to evaluate the effects of topical use of platelet-rich plasma (PRP) on infected wound-healing process in rats.

METHODS

Following the induction of a circular wound, the animals were divided into three groups, including (1) standard control: infected wounds treated with mupirocin (SDCL), (2) non-infected wounds treated with PRP (PRP), and (3) infected group in which the rats were infected with Staphylococcus epidermidis and Pseudomonas aeruginosa and treated with PRP (INF + PRP). To evaluate the effects of PRP on the wound-healing rate, total bacterial count, histopathological assessment, the serum concentrations of sialic acid, C-reactive protein, haptoglobin, and fibrinogen were assessed. Additionally, IL-1β, IL-6, TNF-α, IL-3, NF-κB, iNOS, PDGF, and EGF mRNA level expressions were assessed employing the qRT-PCR method.

RESULTS

The results indicated that topical application of PRP could significantly decrease total bacterial count, the level of C-reactive protein, and pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α) compared to the SDCL group. The administration of PRP also promoted re-epithelization rate by increasing the expression of EGF mRNA level.

CONCLUSION

We could recommend the use of PRP for the treatment of infected wounds owing to its efficiency in decreasing colonization of tissue bacteria, tissue inflammation, and stimulating wound heal-up.

Pain Relief and Antimicrobial Activity in Alveolar Osteitis after Platelet-Rich Fibrin Application—A Non-Randomized Controlled Study

The objective was to compare pain relief in alveolar osteitis achieved by the application of platelet-rich fibrin (PRF) and aspirin cones, and to assess the influence of both treatments on bacterial concentrations in post-extraction wounds. A split-mouth, single-center, non-randomized controlled trial was conducted in 30 patients. Pain relief was assessed using the visual analog scale at three time points (before, 24 h after, and 48 h after intervention). Bacterial concentrations were evaluated from cultures of swab samples collected at the three time points. A Wilcoxon matched-pairs signed-rank test was performed to detect differences in distributions of scalar variables between treatment with PRF and aspirin cones. Pain relief at 24 h and 48 h after treatment was significantly higher (p = 0.003) with PRF application than with aspirin cone placement. Additionally, PRF application caused a significantly higher reduction in aerobic bacteria concentration, an average increase, instead of a decrease, in lactic acid bacilli concentration in the first 24 h, and a significantly greater increase in streptococci concentration at 48 h follow-up. PRF provides better pain relief than aspirin cones in alveolar osteitis. Bacterial concentrations in the extraction wounds are consistent with the pain relief achieved after PRF or aspirin application.

Antibacterial Properties of Canine Platelet-Rich Plasma and Other Non-Transfusional Hemo-Components: An in vitro Study

This in vitro study was carried out to evaluate the potential antibacterial properties of canine non-transfusional hemo-components. Therapeutic formulations commonly used for regenerative medicine purposes (platelet-rich plasma, platelet gel, platelet lysate, fibrin glue), considering both leukocyte-rich and leukocyte-poor formulations, but also platelet-poor plasma and activating substances (thrombin, calcium gluconate), were tested to detect elements with potential antimicrobial properties. The antibacterial effect was tested on different bacterial strains (Staphylococcus aureus subspecies aureus, Staphylococcus cohnii subspecies cohnii, Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae subspecies pneumoniae) isolated from canine wounds and classified as susceptible, multidrug-, extensively, and pandrug-resistant bacteria toward a known panel of human and veterinary antibiotics. The evaluation was carried out by agar gel diffusion method (Kirby-Bauer) and micro-inhibition in broth using microplates and spectrophotometer reading. The study findings confirmed the hypothesized antibacterial properties of canine non-transfusional hemo-components. A more effective bacteriostatic effect was found against Gram-negative bacteria, drug-resistant too. The presence of leukocytes or platelets does not appear to be essential for the antibacterial effect. Further studies should be conducted to evaluate the exact mechanism of action of the antimicrobial activity. However, non-transfusional hemo-components could be a useful natural aid in controlling bacterial infections in dogs.

Combined therapy of ocular surface disease with plasma rich in growth factors and scleral contact lenses

PURPOSE

To review safety and efficacy of combined plasma rich in growth factors (PRGF) eye drops and scleral contact lens (SCL) therapy in patients with ocular surface disease.

METHODS

Patients with ocular surface disease of various etiologies were screened for at least 3 months of concurrent treatment with PRGF and SCL. Retrospective pre- and post-treatment measurements were collected, including patient satisfaction, severity and frequency of dry eye symptoms measured by a modified Symptom Assessment in Dry Eye (SANDE) questionnaire, visual acuity, and number of concurrent treatments.

RESULTS

26 patients with ocular surface disease were included in the study with 20 patients answering the questionnaire (77% response rate). There were no adverse events reported. Most patients thought the combined therapy was better than previous treatments and would recommend to others (80%, 90% respectively). SANDE scores significantly decreased after use of concurrent therapy. There was a small but significant decrease in the number of other concurrent treatments. Visual acuity was unchanged.

CONCLUSIONS

This retrospective cohort study found PRGF used in combination with SCL is safe and significantly decreases symptoms in patients with recalcitrant ocular surface disease.

Autologous platelet concentrates in oral surgery: protocols, properties, and clinical applications

Autologous platelet concentrates (APCs) are a relatively new phenomenon, with initial reports of their regenerative potential published as recently as 1998. Despite their relative infancy, a huge body of evidence exists in support of their capacity to promote osseous and soft tissue regeneration through the physiologic processes of platelet activation and subsequent growth factor release. APCs have transformed many areas of healthcare and are now considered an essential component of the surgical milieu. In this narrative review, we explore the evolution of autologous platelet therapies with a particular emphasis on their contemporary applications in oral surgery, which rather fittingly was the first specialty to report the regenerative potential of APCs.

Antimicrobial Effects of Equine Platelet Lysate

The development of antimicrobial resistant bacteria and the lack of novel antibiotic strategies to combat those bacteria is an ever-present problem in both veterinary and human medicine. The goal of this study is to evaluate platelet lysate (PL) as a biological alternative antimicrobial product. Platelet lysate is an acellular platelet-derived product rich in growth factors and cytokines that is manufactured via plateletpheresis and pooled from donor horses. In the current study, we sought to define the antimicrobial properties of PL on select gram-positive and gram-negative bacteria. Results from an end-point in vitro assay showed that PL did not support bacterial growth, and in fact significantly reduced bacterial content compared to normal growth media. An in vitro assay was then utilized to further determine the effects on bacterial growth dynamics and showed that all strains exhibited a slower growth rate and lower yield in the presence of PL. The specific effects of PL were unique for each bacterial strain: E. coli and P. aeruginosa growth was affected in a concentration-dependent manner, such that higher amounts of PL had a greater effect, while this was not true for S. aureus or E. faecalis. Furthermore, the onset of exponential growth was delayed for E. coli and P. aeruginosa in the presence of PL, which has significant clinical implications for developing a dosing schedule. In conclusion, our findings demonstrate the potential value of PL as a broad-spectrum antimicrobial that would offer an alternative to traditional antibiotics for the treatment of bacterial infection in equine species.

Short- and Long-Term Stability of Plasma Rich in Growth Factors Eye Drops

PURPOSE

To analyze whether plasma rich in growth factors (PRGFs) eye drops preserve their activity and biological properties after storage for 9 and 12 months at -20°C, and at 4°C, and at room temperature (RT) for 3 and 7 days in comparison to fresh samples (t0).

METHODS

PRGF eye drops were obtained from 6 healthy donors. Then, they were stored for 9 and 12 months at -20°C. At each time, different PRGF eye drops samples were thawed and maintained at RT or at 4°C for 3 and 7 days. Platelet-derived growth factor-AB, epidermal growth factor, transforming growth factor-β1, vascular endothelial growth factor, angiopoietin-1, and thrombospondin-1 were analyzed at each time and temperature of storage. In addition, the pH level, the microbial contamination, and the proliferative potential on primary human corneal stromal fibroblasts human keratocytes of each obtained PRGF eye drops were also evaluated.

RESULTS

All growth factor levels were preserved at each time and storage condition. No differences were observed on the human keratocytes proliferation after treatment with PRGF eye drops at any studied time or temperature. No microbial contamination was observed in any of the PRGF eye drops. Finally, the pH levels increased significantly after 9 and 12 months of storage at -20°C compared with t0.

CONCLUSIONS

PRGF eye drops can be stored for up to 12 months without reduction of the main growth factors and proteins and without any microbial contamination. Furthermore, the biological activity of the PRGF eye drops is maintained after storing for 3 and 7 days at 4°C or at RT.

Dentin Growth after Direct Pulp Capping with the Different Fractions of Plasma Rich in Growth Factors (PRGF) vs. MTA: Experimental Study in Animal Model

Background: This study aimed to evaluate the area of dentin growth in rabbit incisors after pulp capping with plasma rich in growth factors (PRGF) compared with mineral trioxide aggregate (MTA) by fluorescence. Methods: twenty-seven upper and lower incisors of rabbits were divided into 4 groups: poor PRGF (F1) (n = 9 teeth), rich PRGF (F2) (n = 8 teeth), ProRoot MTA (positive control, n = 5 teeth), and untreated (NC) (negative control, n = 5). Fluorochrome markers were injected 24 h before surgery and the day before euthanasia, 28 days after the vital pulp therapy (VPT). Two transverse cuts were performed to every tooth: the first cut (A), 1 mm incisal to the gingival margin, and the second cut (B), 5 mm apical to the first cut. The sections were assessed with histomorphometric evaluation by fluorescence microscopy, comparing the dentin area between fluorescence marks and the total mineralized area. Results: The higher percentage of dentin growth was observed in the F2 group (B = 63.25%, A = 36.52%), followed by F1 (B = 57.63%, A = 30,12%) and MTA (B = 38.64%, A = 15.74%). The group with lowest percentage of dentin growth was the NC group (B = 29.22%, A = 7.82%). Significant difference (p < 0.05) was found between F2 group and MTA, also statistically significant difference has been observed comparing dentin growth areas of NC group with F1 and F2 groups. Conclusions: The application of PRGF rich and poor fraction as a pulp capping material stimulated dentin formation more intensively than MTA and NC.

Progress in the use of plasma rich in growth factors in ophthalmology: from ocular surface to ocular fundus

Introduction: The use of blood derivatives and especially Plasma rich in growth factors (PRGF), for regenerative purposes has been a common trend along the last decades in the field of oral surgery, dermatology, orthopedics, and more recently in ophthalmology.Areas covered: PRGF is a type of platelet-rich plasma that is being explored for the treatment of ocular injuries. The present review article highlights 50 ophthalmology-related publications about the application of PRGF in the treatment of acute and chronic pathologies in ophthalmology as well as most relevant challenges and future prospects.Expert opinion: PRGF technology provides a wide range of formulations that can be used therapeutically in many different acute and chronic ocular pathologies. In addition to eye drops enriched with autologous growth factors, PRGF enables the preparation of both immunologically safe and fibrin-based formulations. Recent advances in the field have promoted PRGF storage for 12 months under freezing conditions, its daily use for 7 days at room temperature and the freeze-dried formulation. The thermally treated immunosafe formulation has shown promising clinical results for the treatment of several diseases such as Sjögren syndrome, graft versus host disease or cicatrizing conjunctivitis. In addition, several fibrin formulations have been preclinically evaluated and clinically incorporated as an adjuvant to ocular surface or glaucoma surgeries, dermal fat graft procedures, limbal stem cell expansion and retinal surgeries. The present review explores the latest scientific and clinical data, current challenges, and main prospects of this technology for the treatment of several ocular injuries.

Use of Plasma Rich in Growth Factors and ReGeneraTing Agent Matrix for the Treatment of Corneal Diseases

This study aimed to investigate the use of Plasma Rich in Growth Factors (PRGF) associated with tissue ReGeneraTing Agent (RGTA) drops for the treatment of noninfectious corneal ulcers. RGTA treatment was applied (one drop every two days); however, if ulcer closure was not achieved, PRGF eye drops treatment was added (four times/day). The time taken to reach the ulcer closure, the Best Corrected Visual Acuity (BCVA), intraocular pressure (IOP), Visual Analog Scale (VAS, in terms of frequency and severity of symptoms), and Ocular Surface Disease Index (OSDI) were evaluated. Seventy-four patients (79 eyes) were included, and the mean age was 56.8 ± 17.3 years. The neurotrophic corneal ulcer was the most frequent disorder (n = 27, 34.2%), mainly for herpes virus (n = 15, 19.0%). The time of PRGF eye drops treatment associated with the RGTA matrix was 4.2 ± 2.2 (1.5–9.0) months, and the follow-up period was 44.9 ± 31.5 months. The ulcer closure was achieved in 76 eyes (96.2%). BCVA, VAS and OSDI improved from the baseline (p < 0.001), and IOP remained unchanged (p = 0.665). RGTA and PRGF in noninfectious ulcers were effective and could be a therapeutic alternative for this type of corneal disease.

Clinical and Microbiological Outcomes Associated With Use of Platelet-Rich Plasma in Chronic Venous Leg Uclers: A Randomized Controlled Trial

PURPOSE

To evaluate the susceptibility profiles of Staphylococcus aureus and Pseudomonas aeruginosa strains identified in chronic venous ulcers treated with platelet-rich plasma (PRP) and petrolatum gauze or petrolatum gauze alone and to quantitatively evaluate the bacterial load and biofilm-forming capacities of the detected S. aureus and P. aeruginosa strains.

DESIGN

Randomized controlled trial.

SUBJECTS AND SETTING

The convenience sample included 36 participants; 18 were allocated to the PRP combined with the petrolatum gauze group, and 18 were allocated to the control group, which was treated with petrolatum gauze alone.

METHODS

Thirty-six patients presenting with chronic venous ulcers were consecutively randomized to the PRP group (n = 18) or the petrolatum gauze control group (n = 18). We followed participants for 3 months during treatment and collected swab cultures from their wounds during weeks 1, 6, and 12 or until the wounds healed. The samples were analyzed using mass spectrometry. Antimicrobial susceptibility tests were performed using disk diffusion.

RESULTS

P. aeruginosa was identified in 39 (39%) of 100 samples, and S. aureus was detected in only 10 (10%) samples collected over the study period. At the end of the 12-week treatment period, the wound infections reduced in both the PRP (P = .0078) and control groups (P = .01). The microorganisms were susceptible to most of the tested antimicrobials. The PRP did not increase the bacterial load in the wounds. All S. aureus strains identified showed biofilm-forming capacities and were classified as weak biofilm producers. All P. aeruginosa strains produced biofilm, with 17 strains being classified as weak, 14 as moderate, and 8 as strong biofilm producers.

CONCLUSIONS

The PRP plus petrolatum gauze did not increase bacteriological growth or the microbial load in chronic venous ulcers compared with petrolatum gauze alone and could be a considered as an advanced treatment option for these types of chronic wounds.

Three Manual Noncommercial Methods to Prepare Equine Platelet-Rich Plasma

In light of PRP's increasing popularity in veterinary practice, this study aimed to compare three manual methods to prepare and cool equine PRP. The blood of 18 clinically healthy mares was collected via venipuncture in a blood transfusion bag (method 1), blood tubes (method 2), and a syringe (method 3). In method 1, samples were double centrifuged; method 2 involved one centrifugation, and in method 3 the syringe was kept in an upright position to sediment for 4 h. After processing with three methods, PRP and platelet-poor plasma (PPP) were extracted and assessed for red (RBC) and white blood cell counts (WBC), platelet counts, and viability. In a subset of mares (n = 6), samples were processed with the three methods, and PRP was evaluated at 6 and 24 h postcooling at 5 °C. Method 1 resulted in the highest and method 3 in the lowest platelet concentration (p < 0.05), and the latter also had greater contamination with WBC than the others (p < 0.001). Platelet viability was similar across treatments (p > 0.05). Cooling for 24 h did not affect platelet counts in all methods (p > 0.05); however, platelet viability was reduced after cooling PRP produced by method 3 (p = 0.04), and agglutination increased over time in all methods (p < 0.001). The three methods increased (1.8-5.6-fold) platelet concentration in PRP compared to whole blood without compromising platelet viability. In conclusion, all three methods concentrated platelets and while cooling affected their viability. It remains unknown whether the different methods and cooling would affect PRP's clinical efficacy.

Dental Implants with a Calcium Ions-Modified Surface and Platelet Concentrates for the Rehabilitation of Medically Compromised Patients: A Retrospective Study with 5-Year Follow-Up

Background: Platelet concentrates are biological, autologous products obtained from the patient’s whole blood, consisting of a supraphysiological concentration of platelets and growth factors, that have proved beneficial in different applications in the medical and dental fields. They are used in several medical and dental applications to enhance tissue healing. Previous evidence shows that platelet concentrates may be beneficial in patients with compromised systemic conditions, in which the healing process is impaired. Aim: To evaluate the 5-year clinical outcome of implant treatment using acid-etched implants with calcium ions-modified surface in association with plasma rich in growth factors, in patients with systemic diseases of a different nature. Methods: Charts of 99 medically compromised patients, who had received a total of 224 dental implants from January 2013 to June 2013, were retrospectively evaluated. Patients were divided into four groups, according to their condition: diabetes (n = 39 patients), osteoporosis (n = 36), lupus erythematosus systemic (n = 5), rheumatoid arthritis (n = 19). The main outcomes were implant survival, marginal bone level (MBL) change and complications throughout follow-up. Results: Mean follow-up was 63.06 ± 1.90 months (range 60.1 to 66.4 months). In total, eight implants failed in 6 diabetic patients and 4 in 3 patients with rheumatoid arthritis. Overall 5-year implant survival was 94.6%. In total, 30 complications occurred in 24 patients, mostly transient, and no severe adverse event occurred. Overall MBL change was 0.45 ± 0.12 mm, with no significant differences among groups. Conclusions: In the present sample of medically compromised patients, rehabilitation with calcium ions-modified surface implants associated with plasma rich in growth factors proved to be a safe and effective treatment. The satisfactory results achieved after 5-year follow-up are comparable to those historically reported for healthy patients.

Intrauterine Blood Plasma Platelet-Therapy Mitigates Persistent Breeding-Induced Endometritis, Reduces Uterine Infections, and Improves Embryo Recovery in Mares

Microorganisms, including pathogenic or opportunistic bacteria and fungi, may gain access to the uterus during breeding, and infectious endometritis plays a major role in equine subfertility. This study aimed to assess the post-breeding inflammatory response, endometrial culture, and embryo recovery of mares susceptible to persistent breeding-induced endometritis (PBIE) treated with plasma-rich (PRP) or -poor (PPP) plasma. Mares (n = 12) susceptible to PBIE had three cycles randomly assigned to receive intrauterine infusions of lactate ringer solution (LRS, control), or autologous PRP or PPP pre- (−48 and −24 h) and post-breeding (6 and 24 h). Mares were bred with fresh semen from one stallion. Intrauterine fluid accumulation (IUF) and endometrial neutrophils were assessed every 24 h up to 96 h post-breeding. Uterine cytokines (Ilβ, IL6, CXCL8, and IL10) were evaluated before (0 h), 6, and 24 h post-breeding, and endometrial culture three and nine days after breed. Embryo flushing was performed 8 days post-ovulation. Data were analyzed with mixed model, Tukey’s post-hoc test, and multivariate regression. PRP treatment reduced endometrial neutrophils, post-breeding IUF, and pro-inflammatory cytokines when compared to control-assigned cycles, but not significantly different than PPP. Controls had a significantly higher percentage of positive bacterial cultures (33%) in comparison to PRP-assigned cycles (0%), whereas cycles treated with PPP were not significantly different from the other groups (25%). The PRP-assigned cycles had significantly greater embryo recovery rates (83%) than the control (33%), though not significantly different than PPP (60%). Plasma infusion reduced the duration and intensity of the post-breeding inflammatory response and improved embryo recovery in mares susceptible to PBIE. Platelets incrementally downregulate PBIE and appear to have a dose-dependent antimicrobial property.

Use of autologous plasma rich in growth factors fibrin membrane in the surgical management of ocular surface diseases

PURPOSE

To evaluate the safety and efficacy of the surgical use of autologous plasma rich in growth factors fibrin membrane (mPRGF) in improving corneal wound healing and regeneration in a variety of complex ocular surface defects.

METHODS

Chart review on 15 eyes of 14 included patients undergoing ocular surface intervention using intraoperative mPRGF at the Bascom Palmer Eye Institute and at the Instituto Oftalmológico Fernández-Vega was performed. Patients were grouped based on type of intervention or condition (penetrating keratoplasty, superficial keratectomy, neurotrophic or persistent corneal ulcers, and corneal perforation). Patients were followed for an average of 11 ± 5 months. Main outcomes measured were mPRGF dissolving time, best-corrected visual acuity, and evidence of any persistent epithelial defects, rejections, or complications.

RESULTS

All 15 eyes underwent successful placement of mPRGF. Average dissolving time for fibrin membrane was 21 ± 3 days. mPRGF resulted in total healing of the corneal defects in 13/15 (86.7%) of the treated eyes and partial healing in 2/15 (13.3%) eyes in which persistent epithelial defects were noted on follow-up. Visual acuity improvement was seen in 9/15 (60%) of the cases.

CONCLUSION

The use of autologous mPRGF in the healing and regeneration of the ocular surface is a secure and efficacious surgical option. Our data demonstrate that PRGF fibrin membrane should be contemplated as an important tool to optimize ocular surface regeneration in complex cases.

Plasma rich in growth factors versus Mitomycin C in photorefractive keratectomy

To evaluate the efficacy and safety of plasma rich in growth factors (PRGF) in photorefractive keratectomy (PRK) versus Mitomycin C (MMC).This is a comparative, longitudinal and retrospective case-control study (MMC vs PRGF), in patients with a spherical correction from -0.25 to -8.00 D and cylinder correction from -0.25 to -3.00. The uncorrected distance visual acuity (UDVA), refractive efficacy and safety indices, and changes in endothelial cell density were evaluated. The predictability was assessed with the postoperative manifest spherical equivalent.Forty-four patients (72 eyes) were treated with MMC and twenty-five patients (45 eyes) with PRGF. The final UDVA (LogMar) in MMC was 0.029 ± 0.065 and in PRGF it was 0.028 ± 0.048 (p = 0.383). The efficacy index for MMC was 0.98 ± 0.10 and 1.10 ± 0.46 for patients treated with PRGF (p = 0.062). The safety index for MMC was 1.03 ± 0.11 and 1.12 ± 0.46 (p = 0.158) for PRGF group. The change percentage of endothelial cell density was 0.9 ± 11.6 for MMC and 4.3 ± 13.1 for PRGF (p = 0.593). The predictability for MMC was 92.1% and for the PRGF was 91.9% (p = 0.976). Hyperemia, eye pain and superficial keratitis were observed in 11.1% of the MMC group; no adverse events were observed with the PRGF.The use of PRGF in PRK surgery is as effective as MMC. The PRGF shows a better safety profile than MMC for its intraoperative use in PRK.

An evaluation of the bacteriostatic effect of platelet-rich plasma

Chronic wounds are a considerable health burden with high morbidity and poor rates of healing. Colonisation of chronic wounds by bacteria can be a significant factor in their poor healing rate. These bacteria can develop antibiotic resistance over time and can lead to wound infections, systemic illness, and occasionally amputation. When a large number of micro-organisms colonise wounds, they can lead to biofilm formation, which are self-perpetuating colonies of bacteria closed within an extracellular matrix, which are poorly penetrated by antibiotics. Platelet-rich plasma (PRP) is an autologous blood product rich in growth factors and cytokines that are involved in an inflammatory response. PRP can be injected or applied to a wound as a topical gel, and there is some interest regarding its antimicrobial properties and whether this can improve wound healing. This study aimed to evaluate the in vitro bacteriostatic effect of PRP. PRP was collected from healthy volunteers and processed into two preparations: activated PRP-activated with calcium chloride and ethanol; inactivated PRP. The activity of each preparation against Staphylococcus aureus and Staphylococcus epidermis was evaluated against a control by three experiments: bacterial kill assay to assess planktonic bacterial growth; plate colony assay to assess bacterial colony growth; and colony biofilm assay to assess biofilm growth. Compared with control, both preparations of PRP significantly inhibited growth of planktonic S aureus and S epidermis. Activated PRP reduced planktonic bacterial concentration more than inactivated PRP in both bacteria. Both PRP preparations significantly reduced bacterial colony counts for both bacteria when compared with control; however, there was no difference between the two. There was no difference found between biofilm growth in either PRP against control or against the other preparation. This study demonstrates that PRP does have an inhibitory effect on the growth of common wound pathogens. Activation may be an important factor in increasing the antimicrobial effect of PRP. However, we did not find evidence of an effect against more complex bacterial colonies.

The Management of Postsurgical Wound Complications with Plasma Rich in Growth Factors: A Preliminary Series

BACKGROUND

Postsurgical wound complications constitute a relevant public health issue because of their frequency. There is growing evidence regarding platelet-based autologous therapies that support their use in promoting cutaneous regeneration.

OBJECTIVE

To provide preliminary data regarding the potential benefit of plasma rich in growth factors (PRGF) in the management of postsurgical wound complications.

DESIGN

Three patients suffering from poorly healing severe full-thickness wounds were treated with either one or a combination of different formulations derived from their own blood: autologous clot, fibrin membrane, injectable plasma, or topical ointment. Different treatment protocols are described, and follow-up results are reported.

RESULTS

Within 4 to 12 months, the treated wounds healed completely with no signs of infection, tissue necrosis, or functional impairment. No adverse events were reported.

CONCLUSION

Additional clinical trials with long-term follow-up periods and larger patient populations are needed to establish the efficacy of PRGF technology. However, these preliminary findings suggest that PRGF merits further randomized controlled studies exploring its capacity to accelerate re-epithelialization and restore functional integrity to cutaneous ulcers resulting from surgical complications.

Development and optimization of a personalized fibrin membrane derived from the plasma rich in growth factors technology

PURPOSE

To develop and characterize a new type of plasma rich in growth factors (PRGF) membrane for patients in which immune system is involved in the disease etiology.

METHODS

Blood from three healthy donors was collected to obtain the different fibrin membranes by PRGF technology. PRGF obtained volumes were activated and divided into two groups: PRGF membrane (mPRGF) obtained after incubation at 37 °C for 30 min (control); and is-mPRGF: mPRGF obtained after incubation for 30 min at 56 °C. The concentration of several growth factors, proteins, immunoglobulin E and the complement activity was determined in the different mPRGF. The proliferative potential of heat-inactivated mPRGF were assayed on keratocytes (HK) and conjunctival fibroblasts (HConF). In addition, morphological and physical features of the inactivated mPRGF were evaluated in contrast to the control mPRGF.

RESULTS

Heat-inactivation of the mPRGF preserves the content of most of the growth factors involved in the ocular wound healing while reducing drastically the content of IgE and the complement activity. The heat-inactivated mPRGF conserve the morphological and physical characteristics of the fibrin meshwork in comparison with the control mPRGF. Furthermore, no significant differences were found in the biological activity of the control mPRGF regarding the heat-inactivated mPRGF (is-mPRGF) in any of both ocular cell types evaluated.

CONCLUSIONS

The heat-inactivation of the PRGF membranes (is-mPRGF) reduces drastically the content of IgE and complement activity while preserving the content of most of the proteins and morphogens involved in ocular wound healing. Furthermore, the morphological and physical features of the immunosafe mPRGF were also preserved after heat-inactivation.

Application of platelet-rich plasma in traumatic bone infections

Introduction: Traumatic bone infection represents a clinical challenge for orthopedic surgeons. Traditional treatments include surgical debridement and antibiotic, but prolonged use of antibiotic may lead to colonization of resistant bacteria and other adverse reactions.Areas covered: Platelet-rich plasma (PRP), a biological product extracted from the peripheral blood of patients, has been widely used in the field of tissue repair in recent years. Because if its structural and antibacterial properties, PRP is an innovative option for the prevention and treatment of infections. This review assesses the recent scientific literature on PRP, specifically its in the treatment of infections. To this end, a literature review was conducted using the PubMed and Web of Science databases with the following keywords 'platelet-rich plasma (PRP)'; 'PRP AND traumatic bone infections'; 'PRP AND bone defect'; 'PRP AND antibiotics'; and 'PRP AND wound healing'.Expert opinion: This review focuses on the mechanism of action, preparation methods, clinical applications and other aspects related to PRP to provide a reference for its use in the treatment of traumatic bone infections, thereby enhancing the therapeutic effectiveness and improving the prognosis of patients.

Long-term stability of a novel platelet-rich plasma-based topical serum for cutaneous applications

BACKGROUND

Skin alterations are usually related to chronic diseases that demand sustained and long-term dosages; hence, it is pivotal that the stability of treatments is preserved. A novel storable and endogenous topical serum (ES) based on the patient's own blood has been recently developed.

AIMS

To investigate the long-term stability of the formulation and to provide preliminary data of its biologic potential.

METHODS

Samples from six donors were obtained and either used as fresh samples or cold-stored for 6 months. Physicochemical, rheological, and biological stability of the formulation was determined.

RESULTS

Endogenous topical serum maintained unaltered its organoleptic properties, viscosity, pH, spreadability index, and sterility. The growth factor content including TGFβ-I, EGF, PDGF-AB, HGF, and Ang-I showed no decrease. In contrast, ES showed lower levels of IGF-I once stored. Dermal fibroblasts showed no change in their proliferative activity.

CONCLUSION

Endogenous topical serum showed to maintain its physicochemical and biological properties after six months of storage. ES might reduce the frequency of blood extractions and would enable patients with chronic disorders to maintain a daily use of the product in a minimally invasive way.

Development and Optimization of Freeze-Dried Eye Drops Derived From Plasma Rich in Growth Factors Technology

Purpose

To investigate whether plasma rich in growth factors (PRGF) eye drops maintain their biological potential after a freeze drying process. The addition of a lyoprotectant like trehalose was also evaluated.

Methods

Blood from three healthy donors was collected to obtain eye drops by PRGF technology. The resultant eye drops were divided in four groups: PRGF, freeze-dried PRGF (PRGF lyo), and PRGF lyophilized mixed with 2,5% trehalose (PRGF lyo+2.5T) or 5% trehalose (PRGF lyof+5T). Chemical and biological characteristics were evaluated. Photorefractive keratectomy was performed on C57BL/6 mice which were divided in three treatment groups: control, PRGF, and PRGF lyo. Corneal wound healing and haze formation were evaluated macroscopically. Eyes were collected at 1, 2, 3, and 7 days after surgery, and were processed for histologic studies.

Results

The pH values of PRGF samples increased significantly after the lyophilization process. Osmolarity levels increased significantly in PRGF samples mixed with trehalose in comparison with PRGF samples without protectants. The freeze drying process maintained growth factors levels as well as the biological properties of PRGF eye drops even without the use of lyoprotectants. PRGF lyo treatment significantly decreased the re-epithelialization time and haze formation in photorefractive keratectomy-treated corneas regarding PRGF and control groups. Furthermore, the PRGF lyo group significantly decreased the number of smooth muscle actin-positive cells in comparison with the control group at each time of the study and at days 2 and 3 in the PRGF group.

Conclusions

The freeze drying process preserves the protein and growth factor content as well as the biological properties of PRGF eye drops, even without the use of protectants. Freeze-dried PRGF eye drops accelerate corneal tissue regeneration after photorefractive keratectomy in comparison with the control group.

Translational Relevance

Our study shows the feasibility to preserve the biological capability of PRGF eye drops as freeze-dried formulation, avoiding the addition of protectants.

Efficacy of growth factors for the treatment of peri-implant diseases: a systematic review and meta-analysis

OBJECTIVES

The aim of this study was to conduct a systematic review and meta-analysis on the efficacy of growth factors (GF) on clinical outcomes after treatment (surgical/non-surgical) of peri-implant diseases (peri-implant mucositis and peri-implantitis).

MATERIALS AND METHODS

A protocol was developed to answer the following focused question: Is there any difference for the use of GF for treatment of peri-implant diseases versus comparative GF treatment or without GF? Electronic database and manual searches were independently conducted to identify randomized controlled trials (RCTs). Publications were selected based on eligibility criteria and then assessed for risk-of-bias using the Cochrane Handbook. The primary outcome was probing depth (PD) and bleeding on probing (BOP) reduction along with changes in vertical defect depth (VDD). Changes in clinical attachment level, gingival recession, and plaque index, among others, were studied as secondary outcomes. Based on primary outcomes, random-effects meta-analysis was conducted.

RESULTS

A total of five RCTs were included. GF enhance the reduction of PD (standardized mean difference (SMD) = - 1.28; 95% confidence interval (CI) - 1.75, - 0.79; p = < 0.0001) and BOP (SMD = - 1.23; 95% CI - 1.70, - 0.76; p = < 0.0001) in the management of peri-implant mucositis. For the treatment of peri-implantitis, the use of GF yielded to significantly greater improvement in VDD (SMD = 0.68; 95% CI 0.22, 1.14; p = 0.004); however, there were no significant differences in terms of PD (SMD = 0.08; 95% CI - 1.08, 1.26; p = 0.887) and BOP (SMD = 0.211; 95% CI - 0.20, 0.63; p = 0.317). The overall risk of bias of the included studies was low to unclear.

CONCLUSION

The results of the present systematic review suggest that the addition of GF might enhance the outcomes in the treatment of peri-implant mucositis. However, there is a lack of evidence for supporting additional benefit of GF managing peri-implantitis.

CLINICAL RELEVANCE

Within the limitations of the current systematic review and based on the meta-analyses, (1) the addition of GF for the treatment peri-implant mucositis might be associated with better outcomes in terms of PD and BOP, and (2) an additional benefit of GF for the treatment peri-implantitis could not be determined on the basis of the selected evidence.

Plasma rich in growth factors (PRGF) in non-surgical periodontal therapy: a randomized clinical trial

The aim of this split mouth, double blinded, randomized clinical trial was to evaluate the clinical efficacy of use of Plasma rich in growth factors (PRGF) as an adjunct to scaling and root planing (SRP) in the treatment of periodontal pockets. Twenty six patients (15 males, 11 females) diagnosed with generalized periodontitis with Pocket Depth > 5mm and plaque index score < 1.5, were randomly allocated by using computer generated random sequence, into two groups, one treated with intra-pocket application of PRGF adjunct to SRP and other with SRP alone. The clinical outcomes like pocket depth (PD), relative attachment level (RAL) and sulcus bleeding index (SBI) were assessed at baseline, 3 months and 6 months. Twenty two patients (44 sites) were analyzed at the end of 6 month follow-up, using SPSS 20.0v software. There was a significant statistical difference observed between both the groups favouring SRP +PRGF group in terms of PD (p = 0.007) and RAL (p = 0.021) at the end of 6 month follow-up. Also there was a statistical significant difference (< 0.001) at all time points compared to baseline, for all parameters in intra-group comparison. Moreover, the sites with PD>4mm necessitating further treatment after 6-month follow-up were significantly lesser for SRP+PRGF group. The use of PRGF technology in non-surgical periodontal therapy, by single intra-pocket application in to periodontal pockets as an adjunct to SRP, in chronic periodontitis patients, was found to be effective in reduction of pocket depth and gain in clinical attachment level.

Stability of freeze-dried plasma rich in growth factors eye drops stored for 3 months at different temperature conditions

PURPOSE

The purpose of this study was to analyze the biological content and activity of freeze-dried plasma rich in growth factors eye drops after their storage at 4°C and at room temperature for 3 months with respect to fresh samples (time 0).

METHODS

Plasma rich in growth factors was obtained after blood centrifugation from three healthy donors. After platelet activation, the obtained plasma rich in growth factors eye drops were lyophilized alone or in combination with lyoprotectant (trehalose), then they were stored for 3 months at room temperature or at 4°C. Several growth factors were analyzed at each storage time and condition. Furthermore, the proliferative and migratory potential of freeze-dried plasma rich in growth factors eye drops kept for 3 months at different temperature conditions was evaluated on primary human keratocytes.

RESULTS

The different growth factors analyzed maintained their levels at each time and storage condition. Freeze-dried plasma rich in growth factors eye drops stored at room temperature or 4°C for 3 months showed no significant differences on the proliferative activity of keratocytes in comparison with fresh samples. However, the number of migratory human keratocytes increased significantly after treatment with lyophilized plasma rich in growth factors eye drops kept for 3 months compared to those obtained at time 0. No significant differences were observed between the freeze-dried plasma rich in growth factors eye drops whether mixed or not with lyoprotectant.

CONCLUSION

Freeze-dried plasma rich in growth factors eye drops preserve the main growth factors and their biological activity after storage at room temperature or 4°C for up to 3 months. Lyophilized plasma rich in growth factors eye drops conserve their biological features even without the use of lyoprotectants for at least 3 months.

Persistent Breeding-Induced Endometritis in Mares - a Multifaceted Challenge: From Clinical Aspects to Immunopathogenesis and Pathobiology

Post-breeding endometritis (i.e., inflammation/infection of the endometrium), is a physiological reaction taking place in the endometrium of mares within 48 hours post-breeding, aimed to clear seminal plasma, excess sperm, microorganisms, and debris from the uterine lumen in preparation for the arrival of an embryo. Mares are classified as susceptible or resistant to persistent breeding-induced endometritis (PBIE) based on their ability to clear this inflammation/infection by 48 hours post-breeding. Mares susceptible to PBIE, or those with difficulty clearing infection/inflammation, have a deficient immune response and compromised physical mechanisms of defense against infection. Molecular pathways of the innate immune response known to be involved in PBIE are discussed herein. The role of the adaptive uterine immune response on PBIE remains to be elucidated in horses. Advances in the pathobiology of microbes involved in PBIE are also revised here. Traditional and non-traditional therapeutic modalities for endometritis are contrasted and described in the context of clinical and molecular aspects. In recent years, the lack of efficacy of traditional therapeutic modalities, alongside the ever-increasing incidence of antibiotic-resistant microorganisms, has enforced the development of non-traditional therapies. Novel biological products capable of modulating the endometrial inflammatory response are also discussed here as part of the non-traditional therapies for endometritis.

Wound healing properties and antimicrobial activity of platelet-derived biomaterials

We analyzed the potential antibacterial effects of two different PdB against methicillin-resistant S. aureus and P. aeruginosa. The third-degree burn wound healing effects of PdB was also studied. Blood samples were obtained from 10 healthy volunteers and biological assays of the PdB were performed and the antimicrobial activity against MRSA and P. aeruginosa was determined using disk diffusion (DD), broth microdilution (BMD), and time-kill assay methods. 48 Wistar albino rats were burned and infected with MRSA. Two groups were injected PdB, the control groups were treated with plasma and received no treatment respectively. In the next step, the rats were euthanized and skin biopsies were collected and histopathologic changes were examined. The results of DD and BMD showed that both PdB performed very well on MRSA, whereas P. aeruginosa was only inhibited by F-PdB and was less susceptible than MRSA to PdBs. The time-kill assay also showed that F-PdB has an antibacterial effect at 4 hours for two strains. Histopathological studies showed that the treated groups had less inflammatory cells and necrotic tissues. Our data suggest that PdB may possess a clinical utility as a novel topical antimicrobial and wound healing agent for infected burn wounds.

Incorporating antibiotics into platelet-rich fibrin: A novel antibiotics slow-release biological device

BACKGROUND

The aim of the present in vitro study was to explore the possibility of using platelet-rich fibrin (PRF) as a local sustained released device for antibiotics.

MATERIALS AND METHODS

Platelet-rich fibrin was prepared with the addition of antibiotics (5 mg/ml metronidazole; 150 mg/ml clindamycin; 1 mU/ml penicillin) or saline prior to centrifugation, while collagen sponges served as control. PRFs anti-bacterial properties were examined in an anti-biogram assay with Staphylococcus aureus or Fusobacterium nucleatum at different time intervals after PRF preparation.

RESULTS

The addition of antibiotic solutions at volumes of 2 or 1 ml led to significant changes in PRF's physical properties, while the addition of 0.5 ml solution did not. PRF with saline showed minor anti-bacterial activity, while all PRFs with antibiotics showed significant anti-bacterial activity (p < 0.05). No differences were observed between raw (clot) and pressed (membrane) forms of PRF. Collagen sponges with and without antibiotics showed similar results to PRF. PRF and collagen sponges with antibiotics preserved their anti-bacterial properties 4 days after preparation.

CONCLUSIONS

Platelet-rich fibrin incorporated with antibiotics showed long-term anti-bacterial effect against F. nucleatum and S. aureus. This modified PRF preparation may be used to reduce the risk of post-operative infection in addition to the beneficial healing properties of PRF.

Successful pulp revascularization of an autotransplantated mature premolar with fragile fracture apicoectomy and plasma rich in growth factors: a 3-year follow-up

AIM

This case report demonstrates a positive outcome of the adjuvant use of fragile fracture (FF), which is a technique used to harvest dental pulp stem cells (DPSCs), and platelet-rich plasma (PRP) in a mandibular premolar (tooth 44) with a completely formed root that was transplanted into a surgically created socket and which maintained pulp vitality and function.

SUMMARY

After virtual surgical planning, a 3D tooth replica of tooth 44 was fabricated. A surgical socket was created in the position of tooth 14; then, tooth 44 was extracted and the root dentine was abraded using a turbine diamond bur 3 mm from the apex until a circular groove was prepared around the outer circumference of the root; and then, an FF was performed without damaging the pulp tissue. PRP was placed in the socket, after which the donor tooth was inserted in the recipient area. At 2 weeks post-treatment, orthodontic traction was applied. At 3-year follow-up, the tooth had adequate alignment and was asymptomatic. Response to pulp testing was positive, and the presence of pulp canal obliteration was observed as a sign of pulpal healing.

KEY LEARNING POINTS

Autotransplantation is a good alternative for replacing missing teeth, with repair of tissues and pulp revascularization. Revascularization of an autotransplanted mature tooth using the fragile fracture technique and PRP scaffold is a feasible option and might have positive effects on the long-term outcome of the procedure. Including completely formed teeth as donors in autotransplantation, maintaining vitality and their functions is an option that warrants further study.

Efficacy of plasma rich in growth factor used for dry socket management: a systematic review

Background

The main aim of this systematic review was to assess the dry socket management using plasma rich in growth factor (PRGF) in terms of pain relief, alveolar fossa healing, inflammation, the incidence of dry socket.

Material and Methods

PubMed, Cochrane Library, Elsevier Science Direct, China Biology Medicine (CBM), China National Knowledge Infrastructure (CNKI) and VIP database were searched for the related articles without language limitation. Two reviewers independently searched and evaluated relevant studies. This review has been registered in the website PROSPERO (CRD42018087252).

Results

28 articles were retrieved on PubMed and 98 on other electronic databases in the initial search. In the end, 4 randomized controlled trials (RCTs) were included, with a total of 139 patients enrolled. The descriptive results indicated that the use of PRGF may help reduce pain and inflammation after tooth extraction. To some extent, it is beneficial to the management of dry socket after extraction.

Conclusions

Quality assessment indicated all the included studies were judged to be at high risk of bias with low quality. Hence, it was impossible to make a recommendation for clinical use of PRGF based on the current evidence. Clearly, a multicenter clinical randomized controlled trial is needed urgent to evaluate the safety and efficacy of PRGF for dry socket management.

Key words:plasma rich in growth factor, PRGF, dry socket, systematic review.

Epidermal growth factor vs platelet-rich plasma: Activity against chronic wound microbiota

The objective was to evaluate Staphylococcus aureus and Pseudomonas aeruginosa colonisation of wounds treated with recombinant epidermal growth factor (EGF) and platelet-rich plasma (PRP); to analyse the susceptibility profiles of S. aureus and P. aeruginosa isolates from wounds treated with EGF and PRP; and to describe the presence of infection in EGF-treated and PRP-treated wounds. Experimental study was performed using clinical specimens collected with swabs. Patients were treated with PRP and EGF in the outpatient clinic of a university hospital. Forty-three isolates were obtained from 31 patients, 41.9% (13/31) of whom had been treated with EGF and 58.0% (18/31) with PRP. Ten of the 43 isolates were identified as S. aureus, 60.0% (6/10) of which were isolated from PRP-treated wounds. Among the 33 P. aeruginosa isolates, 66.6% (22/33) were isolated from PRP-treated wounds. Regarding antimicrobial susceptibility, only one strain isolated from an EGF-treated wound was identified as methicillin-resistant S. aureus (MRSA). Among the P. aeruginosa isolates, one obtained from a patient treated with EGF was multidrug-resistant. Patients treated with EGF had no infections during the follow-up period, and there was a significant difference between the 1st and 12th week in wound infection improvement in patients treated with PRP (P = .0078).

Spondylodiscitis due to Cutibacterium acnes following lumbosacral intradiscal biologic therapy: a case report

A 40-year-old woman with a history of chronic low back pain underwent a fluoroscopically guided intradiscal platelet-rich plasma injection (PRP) at the L5-S1 level. She subsequently developed progressive low back pain, night sweats and decreased ability to ambulate. Laboratory work-up revealed elevated acute phase reactants and imaging revealed L5-S1 intervertebral disc and vertebral end-plate abnormalities highly suggestive of spondylodiscitis. Computed tomography-guided aspiration and biopsy cultures grew Cutibacterium acnes and the patient was subsequently treated with intravenous antibiotics without surgical management. To the best of our knowledge, this is the first published case of lumbar spondylodiscitis following an intradiscal PRP injection, and brings to the forefront several clinically relevant issues including the antimicrobial effects of PRP, the role of C. acnes in spine infections and the ideal treatment protocol for intradiscal biologics in order to minimize morbidity and optimize functional outcomes.

Antimicrobial effects of various platelet rich concentrates-vibes from in-vitro studies-a systematic review

Aim

The aim of the current review was to outline the existing information related to antimicrobial properties of various platelet concentrates, as experimented in various in-vitro studies.

Background

One of the most interesting recent landmarks in the field of biological therapy has been the discovery that platelets, in addition to being capable of releasing hundreds of proteins and growth factors, can also release immunomodulatory agents with antimicrobial activity. Several international research groups have reported antimicrobial activities in both human platelets and other types of platelet rich plasma preparations.

Review Result

This review was carried-out pursuing a systematic approach. An electronic search was conducted on MEDLINE and GOOGLE SCHOLAR databases using suitable search terminologies. It included preclinical studies which assessed the antimicrobial activity of Autologous Platelet Concentrates(APC).Ten in-vitro studies and one animal study, which investigated APC effects on various microorganisms, were included. Almost in all the included in-vitro studies, it was found that complete breakdown of microbial load could not be achieved by any of the APC preparations but there occurred a reduction in the growth of microorganisms. Thus APCs displayed a bacteriostatic rather than bacteriocidal activity.The only animal study included in this review which had both in-vitro and in-vivo evaluation, also showed reduction of infection caused by different microorganisms.

Conclusion

Although the precise mechanism of synergy with microbial pathogens needs further validation, platelet concentrates proved to have antimicrobial properties.

Platelet-Rich Plasma for the Treatment of Tissue Infection: Preparation and Clinical Evaluation

IMPACT STATEMENT

The clinical application of platelet-rich plasma (PRP) has been widely studied for its effects on trauma or injury repair/regeneration, however the antibacterial property of PRP has been overlooked. Increasing evidence suggests PRP as a good antibacterial agent and that it could help prevent/treat tissue infection. This review emphasizes the importance of PRP's antibacterial property and summarizes the preclinical and clinical findings regarding the application of PRP in the prevention and treatment of wound and bone infection. The use of biocompatible PRP may be advantageous for tissue infection treatment due to its inherent antibacterial and healing promoting properties.

Antimicrobial Effect of Platelet-Rich Plasma against Porphyromonas gingivalis

Aim

The aim of our study was to evaluate whether there was a difference in antimicrobial effect between the PRP of healthy volunteers and that of patients with chronic periodontitis against P. gingivalis, which was fresh cultured from subgingival plaque.

Methods

Subgingival plaque of patients with moderate and severe chronic periodontitis was collected to isolate P. gingivalis. The PRP of four individuals with healthy periodontium and four patients with moderate and severe periodontitis were collected with a specific kit using a two-centrifuge procedure, and then, the antibacterial properties against P. gingivalis were tested, through their minimum inhibitory concentration (MIC), adhesion resistance assay, and biofilm susceptibility assay.

Results

P. gingivalis was successfully isolated from the subgingival plaque of the 21st patient. The round, smooth, and black colony appeared in the agar disk after 7–10 days of incubation under anaerobic conditions. Bacterial identification was performed by MALDI-TOF and confirmed by PCR. All PRP samples tested showed the ability to inhibit P. gingivalis growth. The MIC value (expressed as fraction of PRP) was 1/2, and PRP prevented P. gingivalis attachment on the disk surface. However, PRP did not have a strong effect on the suppression of P. gingivalis biofilm.

Conclusion

PRP of individuals with healthy periodontium and chronic periodontitis patients showed antibacterial properties against P. gingivalis. This material can become an adjunct to periodontal treatment.

Three-dimensional bone evaluation after surgical treatment with plasma rich in growth factors of Medication Related Osteonecrosis of the Jaw (MRONJ): A report of 3 cases

Introduction

Medication Related Osteonecrosis of the Jaw (MRONJ) is an adverse effect of antiresorptive and antiangiogenic agents that consists of progressive bone destruction in the maxillofacial area. The purpose of this study is to analyze the effect on bone volume of a surgical protocol using plasma rich in growth factors (PRGF) for successfully treating MRONJ.

Methods

Three patients were treated combining surgical debridement with PRGF. Cone bean computed tomography scans were taken prior to surgery and 12 months after to measure bone volume changes. Biopsies were taken for histology analysis during surgery.

Results

All patients showed a complete soft tissue and bone healing with pain, discomfort, and neural symptoms resolution for a follow up period of 30 months. A total of 12 to 30% of bone volume gain was found at 12 months after surgery.

Conclusions

PRGF in combination with surgery may be effective in treating MRONJ. Future trials must be performed to confirm these results, including bone volume analysis.

Antimicrobial and antibiofilm potential of injectable platelet rich fibrin-a second-generation platelet concentrate-against biofilm producing oral staphylococcus isolates

Injectable Platelet rich fibrin (i-PRF) is a platelet concentrate that has been extensively used for multiple medical purposes and is a valuable adjunct for the regeneration of damaged tissues in surgical procedures. The enriched bioactive substances in i-PRF are responsible for speeding the wound healing process. Infection of biofilm producing bacteria in surgical wounds is becoming a serious threat. Research in this field is focused on new strategies to fight infections and to reduce the healing time. The present study was aimed to evaluate the in vitro antimicrobial and antibiofilm effects of i-PRF against oral pathogenic biofilm producing staphylococcus bacteria isolated from patient with dental and oral abscess. The antibacterial activity of i-PRF, was determined through broth microdilution as minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). i-PRF exhibited bactericidal activity against both non biofilm and biofilm producing bacteria. i-PRF could be potential antimicrobial peptide used to combat postoperative infections caused by biofilm producing staphylococcus.