Autologous Platelet-Rich Plasma for the Treatment of Pattern Hair Loss

Update on Platelet-Rich Plasma and Platelet-Rich Fibrin for Dermatologic Surgery: Addressing Knowns and Unknowns

BACKGROUND

Autologous and allogeneic platelet-rich plasma (PRP) in addition to its derivatives, such as platelet-rich fibrin (PRF), are broadly accepted therapeutic approaches in orthopedics, otolaryngology, sports medicine, plastic surgery, and oral and maxillofacial surgery. However, the absence of expert consensus, standardized protocols, and varying outcomes pose challenges to their broader acceptance in cosmetic dermatology and dermatologic surgery.

OBJECTIVE

To offer a contemporary literature overview of PRP and PRF, focusing on fundamental aspects of the technology, diversity of commercially accessible systems, and shed light on present-day controversies within the field.

METHODS

A systemic review of PRP and PRF literature was conducted, utilizing search engine databases: Cochrane Database of Systematic Reviews, Embase, Ovid MEDLINE, and PubMed. Emphasis was placed on scrutinizing higher level-of-evidence articles, specifically randomized control trials, systematic reviews, and meta-analyses (Level 1A-2A), with particular emphasis on recent data that have not been well reviewed in other publications from January 2022 to May 2024.

RESULTS

An increasing body of literature affirms advantages of PRP products in dermatology, spanning wound care, facial rejuvenation, scar revision, and hair growth.

CONCLUSION

A foundational understanding of variation in preparation protocol, outcomes, and timing of administration is needed to better comprehend market dynamics, patient demand, and strategies for integrating PRP into dermatologic practice.

Concentrated growth factor therapy as cosmetic treatment in discoid lupus erythematosus

Discoid lupus erythematosus (DLE) is a disfigurement disease. The atrophic scar and hair loss of this disease are followed by cosmetic defects and profoundly impact psychological health. Concentrated growth factor (CGF) has been widely adopted in medical cosmetology. Here we report a 36-year-old female systemic lupus erythematosus patient with a 5-year history of alopecia in DLE, who was recommended for CGF therapy and experienced hair regrowth. We suggest that CGF may be an effective cosmetic treatment for DLE.

Potential application of PBM use in hair follicle organoid culture for the treatment of androgenic alopecia

Androgenic alopecia is a hereditary condition of pattern hair loss in genetically susceptible individuals. The condition has a significant impact on an individual's quality of life, with decreased self-esteem, body image issues and depression being the main effects. Various conventional treatment options, such as minoxidil, finasteride and herbal supplements, aim to slow down hair loss and promote hair growth. However, due to the chronic nature of the condition the financial cost of treatment for androgenic alopecia is very high and conventional treatment options are not universally effective and come with a host of side effects. Therefore, to address the limitations of current treatment options a novel regenerative treatment option is required. One promising approach is organoids, organoids are 3D cell aggregates with similar structures and functions to a target organ. Hair follicle organoids can be developed in vitro. However, the main challenges are to maintain the cell populations within the organoid in a proliferative and inductive state, as well as to promote the maturation of organoids. Photobiomodulation is a form of light therapy that stimulates endogenous chromophores. PBM has been shown to improve cell viability, proliferation, migration, differentiation and gene expression in dermal papilla cells and hair follicle stem cells. Therefore, photobiomodulation is a potential adjunct to hair follicle organoid culture to improve the proliferation and inductive capacity of cells.

Platelet-Rich Plasma for Androgenetic Alopecia: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Platelet-rich plasma (PRP) contains a variety of growth factors and has been widely used in maxillofacial surgery, orthopedics, plastic surgery, ophthalmology, and other fields. In recent years, with the increasing morbidity of androgenetic alopecia (AGA), the use of PRP has also increased. The objective of this article was to evaluate the efficacy and safety of PRP for AGA. We searched PubMed, Embase, Web of Science, and Cochrane Library, covering the databases from their earliest records until March 2022. We performed a systematic review and meta-analysis of randomized controlled trials (RCTs) to explore the effects of PRP for hair density, hair count, and hair diameter in AGA. Nine trials involving 238 patients were included. The meta-analysis showed that PRP for AGA increased hair density at 3 and 6 months with statistically significant differences compared with the placebo (P < .05). PRP also increased hair count and hair diameter compared with the baseline, but there was no significant difference compared with the placebo (P > .05). Two of the 7 studies reported adverse reactions. No serious adverse reactions were found. In conclusion, PRP is an effective and safe treatment for increasing the hair density in AGA. Trial registration: The systematic review was registered with PROSPERO (CRD42022362432).

Use of Activated Platelet-Rich Plasma (A-PRP) on Alopecia: A Systematic Review and Meta-Analysis

Alopecia affects perceptions of age, beauty, success, and adaptability. Hair loss can be caused by genetic, physiological, environmental, and immunologic factors. The current treatment for alopecia is varied. This systematic review and meta-analysis evaluates activated platelet rich plasma (A-PRP) for alopecia treatment. The objective of this review was to assess the clinical efficacy and safety of A-PRP injections in alopecia patients. We compared the safety, limitations, and outcomes of A-PRP use with those of previous research on alopecia. We searched PubMed, EMBASE, the Cochrane Database, and Google Scholar for relevant articles. We included all primary clinical studies involving patients that evaluated A-PRP. Twenty-nine articles, which included 864 patients, met the eligibility criteria and were analyzed for qualitative review. Our review found 27 studies that indicated A-PRP was significantly effective in treating alopecia, especially for improving hair density before and after therapy (n = 184, mean difference [MD] = 46.5, I2 = 88%, 95% CI: 29.63, 63.37, P < .00001), as well as when comparison was made between treatment and control groups (n = 88, MD = 31.61, I2 = 80%, 95% CI: 6.99, 56.22, P = .01), and of terminal hair density between treatment and control groups (n = 55, MD = 26.03, I2 = 25%, 95% CI: 8.08, 43.98, P = .004); hair counts after therapy (n = 85, MD = 12.79, I2 = 83%, 95% CI: -5.53, 31.12, P = .0006); promoting hair regrowth; folliculogenesis; reducing hair loss; combining with follicular unit extraction (FUE) surgery; and initiating the hair cycle. Two studies did not report significant results. This is the first systematic review and meta-analysis of A-PRP as a treatment option for alopecia. A-PRP appears to be a promising and safe method for treating alopecia.

LEVEL OF EVIDENCE: 4

Innovative Approaches and Advances for Hair Follicle Regeneration

Pathological hair loss (also known as alopecia) and shortage of hair follicle (HF) donors have posed an urgent requirement for HF regeneration. With the revelation of mechanisms in tissue engineering, the proliferation of HFs in vitro has achieved more promising trust for the treatments of alopecia and other skin impairments. Theoretically, HF organoids have great potential to develop into native HFs and attachments such as sweat glands after transplantation. However, since the rich extracellular matrix (ECM) deficiency, the induction characteristics of skin-derived cells gradually fade away along with their trichogenic capacity after continuous cell passaging in vitro. Therefore, ECM-mimicking support is an essential prelude before HF transplantation is implemented. This review summarizes the status of providing various epidermal and dermal cells with a three-dimensional (3D) scaffold to support the cell homeostasis and better mimic in vivo environments for the sake of HF regeneration. HF-relevant cells including dermal papilla cells (DPCs), hair follicle stem cells (HFSCs), and mesenchymal stem cells (MSCs) are able to be induced to form HF organoids in the vitro culture system. The niche microenvironment simulated by different forms of biomaterial scaffold can offer the cells a network of ordered growth environment to alleviate inductivity loss and promote the expression of functional proteins. The scaffolds often play the role of ECM substrates and bring about epithelial-mesenchymal interaction (EMI) through coculture to ensure the functional preservation of HF cells during in vitro passage. Functional HF organoids can be formed either before or after transplantation into the dermis layer. Here, we review and emphasize the importance of 3D culture in HF regeneration in vitro. Finally, the latest progress in treatment trials and critical analysis of the properties and benefits of different emerging biomaterials for HF regeneration along with the main challenges and prospects of HF regenerative approaches are discussed.

Melatonin promotes the development of the secondary hair follicles by regulating circMPP5

BACKGROUND

The quality and yield of cashmere fibre are closely related to the differentiation and development of secondary hair follicles in the skin of cashmere goats. The higher the density of secondary hair follicles, the higher the quality and yield of cashmere from the fleece. Development of secondary hair follicles commences in the embryonic stage of life and is completed 6 months after birth. Preliminary experimental results from our laboratory showed that melatonin (MT) treatment of goat kids after their birth could increase the density of secondary hair follicles and, thus, improve the subsequent yield and quality of cashmere. These changes in the secondary hair follicles resulted from increases in levels of antioxidant and expression of anti-apoptotic protein, and from a reduction in apoptosis. The present study was conducted to explore the molecular mechanism of MT-induced secondary hair follicle differentiation and development by using whole-genome analysis.

RESULTS

MT had no adverse effect on the growth performance of cashmere kids but significantly improved the character of the secondary hair follicles and the quality of cashmere, and this dominant effect continued to the second year. Melatonin promotes the proliferation of secondary hair follicle cells at an early age. The formation of secondary hair follicles in the MT group was earlier than that in the control group in the second year. The genome-wide data results involved KEGG analysis of 1044 DEmRNAs, 91 DElncRNAs, 1054 DEcircRNAs, and 61 DEmiRNAs which revealed that the mitogen-activated protein kinase (MAPK) signaling pathway is involved in the development of secondary hair follicles, with key genes (FGF2, FGF21, FGFR3, MAPK3 (ERK1)) being up-regulated and expressed. We also found that the circMPP5 could sponged miR-211 and regulate the expression of MAPK3.

CONCLUSIONS

We conclude that MT achieves its effects by regulating the MAPK pathway through the circMPP5 sponged the miR-211, regulating the expression of MAPK3, to induce the differentiation and proliferation of secondary hair follicle cells. In addition there is up-regulation of expression of the anti-apoptotic protein causing reduced apoptosis of hair follicle cells. Collectively, these events increase the numbers of secondary hair follicles, thus improving the production of cashmere from these goats.

An umbrella review of the use of platelet-rich plasma in the treatment of androgenetic alopecia

OBJECTIVE

To evaluate the efficacy of platelet-rich plasma (PRP) in the treatment of androgenetic alopecia, as well as establish an effective treatment protocol and optimal PRP preparation procedure.

METHODS

We searched the PubMed, Scopus, Embase, Cochrane, CNKI, and Wanfang databases from inception to October 29, 2021, using PROSPERO's International Prospective Register of Systematic Reviews (registration ID: CRD42022295921).

RESULTS

The original literature search revealed 215 reviews; after duplication removal, 89 papers were eliminated, 95 were eliminated after reading the titles and abstracts, and eventually, 28 articles were included after reading the complete text.

CONCLUSIONS

PRP treatment for androgenetic alopecia is effective, and we recommend the following: (1) a PRP volume of at least 0.05 ml/cm² , preferably 0.1 ml/cm² ; (2) at least three consecutive treatments at an interval of 1 month; (3) intensive therapy is beneficial and can be provided from 3 to 6 months after continuous treatment; (4) objective indicators such as hair diameter, hair count; (5) long-term follow-up.

Autologous Platelet-Rich Plasma (PRP) for Treating Androgenetic Alopecia: A Novel Treatment Protocol Standardized on 2 Cases

Platelet-rich plasma (PRP) treatment has emerged in recent years as a valuable, effective, and affordable treatment for androgenetic alopecia. Androgenetic alopecia is the most common type of alopecia, affecting both men and women, and is characterized by diminished hair follicles mainly pronounced in the frontal region and vertex. A considerable variety of PRP treatment regimens have been described so far, but there is no consensus on the standardization of PRP preparation or administration protocol. Our study was conducted on two patients to test the efficacy of a new PRP application protocol of only two treatments by using a combination of a PRP collecting device and a conventional kit. Efficacy of treatment was assessed after a 6-month follow-up by artificial intelligence (AI)-driven software on microscopic images of treated regions. An average number of hairs, cumulative hair thickness, and the number of follicular units increased in the vertex region of both patients by 30/59%, 35/53%, and 14/48%, respectively. The novel treatment regimen showed significant effectiveness in only six months.

The Impact of Autologous Platelet Concentrates on the Periapical Tissues and Root Development of Replanted Teeth: A Systematic Review

Introduction: In many cases, the replanted teeth may undergo resorption or ankyloses. Recent studies show that autologous platelet concentrates (APCs) may improve the outcomes of tooth replantation. The aim of this systematic review was to summarize and critically appraise the currently available literature on the use of APCs before tooth replantation. Methodology: An electronic search was conducted on the following research databases: PubMed/MEDLINE, ISI Web of Science, EMBASE and Scopus. The following medical subject heading (MeSH) keywords used were: ((tooth replantation) OR (replanted tooth) OR (teeth replantation) OR (replanted teeth)) AND ((autologous platelet concentrate) OR (platelet-rich plasma) OR (platelet-rich fibrin) OR (autologous platelet)). The studies’ data was extracted, and the research’ quality was rated using the CARE and ARRIVE protocols. Results: Ten case reports and three animal studies, one cell study and one study, which included both animal and in vitro experiments, were included in this review. In majority of the studies, APCs improved the outcomes of tooth replantation. However, there were various sources of bias in the most of the research, which may have influenced the results. Conclusions: Although majority of the studies indicate that APCs may improve outcomes of tooth replantation, majority of the studies contained numerous sources of bias. Additionally, the sample size of the included subjects is inadequate to predict the clinical efficacy of APCs in management of replanted teeth. Large-scale, multi-center and long-term studies are required to ascertain the efficacy of APCs in improve the outcomes of tooth replantation.

Platelet-Rich Plasma Treatment for Accelerated Androgenetic Alopecia Pattern Hair Loss After COVID-19 Infection: A Case Series

BACKGROUND

Hair-related manifestations such as alopecia areata or telogen effluvium were reported during COVID-19 disease. Accelerated hair loss with androgenetic alopecia (AGA) pattern or management has not been discussed before.

AIMS

This study aimed to examine the accelerated AGA pattern hair loss and management with PRP treatment.

MATERIALS AND METHODS

This study was designed prospectively and nine patients included to study confirmed PCR test for COVID-19 infection. Patients underwent platelet-rich plasma (PRP) injections for 4 sessions. Results were accessed with the hair pull test (HPT) and self-administered hair growth questionnaire (HGQ).

RESULTS

Nine patients were admitted with complaints of hair loss after an average of 220 ± 24.2 (min: 182 max: 264) day after recovery of COVID-19. Mean age of the patients was 33.8 ±8.4 years old (min: 26, max: 52). Six (66.7%) patients were male, and three (33.3%) of them were female. HPT score decreased to 6.0 ± 1.6 after the first PRP application (p = 0.007, CI 95%:2.7-5.2) and decreased to 1.2 ± 0.8 after the last PRP session (p = 0.008, CI 95%: 6.4-11.1). Five (55.5%) of the patients described the treatment as "very effective" after treatment with HGQ.

CONCLUSIONS

Accelerated hair loss associated with COVID-19 continues in long term and PRP treatment provides a satisfactory solution.

Extending the working properties of liquid platelet-rich fibrin using chemically modified PET tubes and the Bio-Cool device

OBJECTIVES

Platelet-rich fibrin (PRF) has been utilized in regenerative medicine as a concentration of autologous platelets and growth factors that stimulates tissue regeneration. More recently, liquid-PRF (also called injectable-PRF; i-PRF) has been brought to market utilizing PET plastic tubes. Due to new advances made in tube technology, the first aim of the present study was to investigate the liquid consistency of liquid-PRF utilizing both standard and chemically modified PET plastic tubes. Furthermore, it is well known that the conversion of PRF into a fibrin matrix is derived from the temperature-controlled enzymatic process that converts liquid fibrinogen and thrombin to solid fibrin. This study also investigated for the first time the use of a cooling device (Bio-Cool) to extend the liquid working properties of liquid-PRF.

MATERIALS AND METHODS

In total, 30 participants enrolled in this study. From each patient, four tubes of liquid-PRF were drawn, two standard white Vacuette tubes and two blue chemically modified hydrophobic tubes. Following centrifugation at 700 RCF-max for 8 min in a Bio-PRF horizontal centrifuge, one white and one blue tube were kept upright at room temperature, while the other white and blue tube were placed within the cooling device. Thereafter, the liquid-PRF layers were monitored over time until clotting occurred. Patient gender, age, and altitude above sea level (+ 5000 ft) were recorded and compared for clotting times.

RESULTS

The findings from the present study demonstrated that the chemically modified PET tubes performed 37% better than the control tubes (extended the working properties of liquid-PRF by over 20 min). Most surprisingly, tubes kept in the cooling device demonstrated an average of 90 min greater working time (270% improvement). While patients living at altitude did significantly improve the clotting ability of liquid-PRF, no differences were observed when comparing male vs female or younger vs older patients in liquid-PRF clotting times.

CONCLUSIONS

Cooling of blood following centrifugation represented a 270% improvement in working properties of liquid-PRF. Optimization of liquid-PRF tubes utilizing chemically modified hydrophobic PET tubes also delayed the clotting process by 37%. Patient gender and age had little relevance on liquid-PRF.

CLINICAL RELEVANCE

The present findings demonstrate for the first time that cooling of liquid-PRF is able to extend the working properties of liquid-PRF by over 90 min. Thus for clinicians performing longer clinical procedures, the cooling of blood may represent a viable strategy to improve the working time of liquid-PRF in clinical practice.

Platelet-rich plasma for androgenic alopecia: A randomized, placebo-controlled, double-blind study and combined mice model experiment

BACKGROUND

Platelet rich plasma (PRP) has been accepted as a potential therapy for treating androgenetic alopecia (AGA).

OBJECTIVE

To fully clarify the underling molecular mechanisms of PRP action on hair growth and promote its clinical applications.

METHODS

In this study, we used mice models and protein biochip to explore the specific mechanisms of PRP regulating hair growth. Then, we performed a randomized, placebo-controlled, double-blind, half-head study of 52 AGA patients to verify the therapeutic efficacy of PRP in Chinese AGA patients.

RESULTS

The results confirmed that PRP treatment boosted hair regrowth, accelerated hair cycling, and the effect sustained for more than one hair cycle in mice. Protein biochip evaluation confirmed remarkably upregulated β-Catenin, PDGF, and AKT signaling and repressed p53 signaling in PRP injection group. Clinically, mean hair count, density, diameter, and anagen hair ratio in PRP group showed a significant improvement at 6 month comparing to control side.

CONCLUSIONS

Overall, we elucidated the specific molecular mechanism of PRP action on hair growth and proved the therapeutic efficacy and safety of PRP in Chinese AGA patients.

A technical note on contamination from PRF tubes containing silica and silicone

Background

Platelet-rich fibrin (PRF) has been widely utilized in modern medicine and dentistry owing to its ability to rapidly stimulate neoangiogenesis, leading to faster tissue regeneration. While improvements over traditional platelet rich plasma therapies (which use chemical additives such as bovine thrombin and calcium chloride) have been observed, most clinicians are unaware that many tubes utilized for the production of ‘natural’ and ‘100% autologous’ PRF may in fact contain chemical additives without appropriate or transparent knowledge provided to the treating clinician. The aim of this overview article is therefore to provide a technical note on recent discoveries related to PRF tubes and describe recent trends related to research on the topic from the authors laboratories.

Methods

Recommendations are provided to clinicians with the aim of further optimizing PRF clots/membranes by appropriate understanding of PRF tubes. The most common additives to PRF tubes reported in the literature are silica and/or silicone. A variety of studies have been performed on their topic described in this narrative review article.

Results

Typically, PRF production is best achieved with plain, chemical-free glass tubes. Unfortunately, a variety of other centrifugation tubes commonly used for lab testing/diagnostics and not necessarily manufactured for human use have been utilized in clinical practice for the production of PRF with unpredictable clinical outcomes. Many clinicians have noted an increased variability in PRF clot sizes, a decreased rate of clot formation (PRF remains liquid even after an adequate protocol is followed), or even an increased rate in the clinical signs of inflammation following the use of PRF.

Conclusion

This technical note addresses these issues in detail and provides scientific background of recent research articles on the topic. Furthermore, the need to adequately select appropriate centrifugation tubes for the production of PRF is highlighted with quantitative data provided from in vitro and animal investigations emphasizing the negative impact of the addition of silica/silicone on clot formation, cell behavior and in vivo inflammation.

Alopecia areata: a review on diagnosis, immunological etiopathogenesis and treatment options

Patients suffering from alopecia areata (AA) can lose hair in focal regions, the complete scalp, including eyelashes and eyebrows, or even the entire body. The exact pathology is not yet known, but the most described theory is a collapse of the immune privilege system, which can be found in some specific regions of the body. Different treatment options, local and systemic, are available, but none of them have been proven to be effective in the long term as well for every treatment there should be considered for the possible side effects. In many cases, treated or non-treated, relapse often occurs. The prognosis is uncertain and is negatively influenced by the subtypes alopecia totalis and alopecia universalis and characteristics such as associated nail lesions, hair loss for more than 10 years and a positive familial history. The unpredictable course of the disease also makes it a mental struggle and AA patients are more often associated with depression and anxiety compared to the healthy population. Research into immunology and genetics, more particularly in the field of dendritic cells (DC), is recommended for AA as there is evidence of the possible role of DC in the treatment of other autoimmune diseases such as multiple Sclerosis and cancer. Promising therapies for the future treatment of AA are JAK-STAT inhibitors and PRP.

Evaluation of 24 protocols for the production of platelet-rich fibrin

Background

The aim of this study was to evaluate 24 protocols for the production of platelet rich fibrin (PRF) produced via horizontal centrifugation to better understand cell separation following protocols at various times and speeds.

Methods

All protocols were compared utilizing a recent method to quantify cells in PRF in 1 mL sequential layers pipetted from the upper layer downwards until all 10 mL were harvested. In total, 960 complete blood counts (CBCs) were investigated. Both solid and liquid-based PRF protocols were investigated following 24 protocols involving 6 relative centrifugal force (RCF) values (100, 200, 400, 700, 1000 and 1200g) at 4 centrifugation times (3, 5, 8 and 12 min).

Results

In general, platelets could more easily accumulate in the upper 4 layers when compared to leukocytes owing to their lower cellular density. Protocol time seemed to have a greater impact on the final cell layer separation when compared to the effect of speed. Protocols of greater than 8 min at 400g led to no leukocyte accumulation in the upper PRF layers (found specifically within the buffy coat). Protocols at or below 200g were unable to effectively accumulate platelets/leukocytes. The optimal centrifugation speed and time for solid-PRF ranged between 400 and 700g for 8 min. It was noted that variability in patient baseline platelet/leukocyte/erythrocyte counts (hematocrit) significantly affected cell layer separation. This finding was more pronounced at lower centrifugation speeds.

Conclusions

Within the investigated ranges, a protocol of 700g for 8 min presented the highest yield of platelets/leukocytes evenly distributed throughout the upper PRF layers.

Evaluation of platelet-rich plasma as a treatment for androgenetic alopecia: A randomized controlled trial

BACKGROUND

Platelet-rich plasma (PRP) shows promise as an androgenetic alopecia (AGA) treatment.

OBJECTIVE

To conduct a randomized placebo-controlled split-scalp study to investigate the effects of PRP on hair regrowth and thickness.

METHODS

Two 7.6-cm × 7.6-cm squares were tattooed on the scalps of 35 study participants with AGA. Areas were randomly assigned to intradermal injection with PRP or saline. Participants received 3 monthly treatment sessions with evaluation 3 months after the final treatment.

RESULTS

Hair density in the PRP-treated area was significantly increased compared with baseline at all visits. At the final assessment, hair density in PRP-treated areas increased from 151 ± 39.82 hairs/cm² at baseline to 170.96 ± 37.14 hairs/cm², a mean increase of approximately 20 hairs/cm² (P < .05). However, hair density in placebo-treated areas also increased from 151.04 ± 41.99 hairs/cm² to 166.72 ± 37.13 hairs/cm² (P < .05). There was no significant difference in hair density change between the 2 groups (P > .05). No serious adverse events were reported.

LIMITATIONS

Possible PRP diffusion due to split-scalp study design as well as microinjections causing microinjury to both sides.

CONCLUSION

PRP may have benefit in increasing hair density.

Improved growth factor delivery and cellular activity using concentrated platelet-rich fibrin (C-PRF) when compared with traditional injectable (i-PRF) protocols

OBJECTIVES

Several studies have recently demonstrated that only marginal improvements in platelet and leukocyte concentrations are achieved following standard injectable platelet-rich fibrin (i-PRF) protocols. Due to these previous findings, a novel harvesting technique was recently developed to collect higher concentrations of platelets/leukocytes specifically from the buffy coat layer (C-PRF) following faster centrifugation protocols. The aim of this study was to investigate the regenerative properties and effects on growth factor release and cellular activity of PRF collected through this novel harvesting technique compared to standard i-PRF protocols.

MATERIALS AND METHODS

The upper 1-ml layer collected through standard i-PRF protocols at low centrifugation speeds was compared with 1 mL of C-PRF collected from the buffy coat layer following high centrifugation protocols (3000×g for 8 min on a horizontal centrifuge) to specifically concentrate cells within the platelet/leukocyte-rich buffy coat layer. Thereafter, the expression of seven different growth factors, including PDGF-AA, PDGF-AB, PDGF-BB, TGF-β1, VEGF, IGF-1, and EGF, was characterized for up to 10 days. Then, gingival fibroblast biocompatibility was investigated at 24 h (live/dead assay); migration was investigated at 24 h; proliferation was investigated at 1, 3, and 5 days; and the expression of PDGF and TGF-β was investigated at 3 days. Collagen 1 immunostaining was also quantified at 14 days.

RESULTS

At all investigated time periods, a significant increase in growth factor release was observed in C-PRF. In particular, the release of PDGF-AA, TGF-β1, and EGF exhibited the highest increases when compared with that in i-PRF. While both i-PRF and C-PRF exhibited high biocompatibility and induced significantly higher fibroblast migration and proliferation when compared with that of the control tissue culture plastic group, C-PRF showed the greatest potential for cell migration and proliferation. Furthermore, C-PRF induced significantly higher mRNA levels of TGF-β and PDGF levels at 3 days and greater collagen 1 staining when compared with induced by i-PRF.

CONCLUSIONS

In the present study, it was found that C-PRF collected specifically from the buffy coat layer following higher centrifugation protocols exhibited an up to a threefold increase in growth factor release when compared with that exhibited by standard i-PRF. This significantly promoted higher gingival fibroblast migration, proliferation, gene expression, and collagen I synthesis.

CLINICAL RELEVANCE

The findings of the present study demonstrate that a more potent formulation of liquid platelet concentrate than that obtained from the upper plasma layer following a short and slow centrifugation protocol (i-PRF protocol) can be obtained for clinical use by specifically harvesting cells in the platelet- and leukocyte-rich buffy coat layer following an 8-min 3000×g centrifugation protocol (C-PRF protocol).

Investigation of optimum transplant and extraction density based on the data from the donor area of Chinese androgenetic alopecia patients: a multicenter, retrospective study

The rise in the incidence of androgenetic alopecia (AGA) in China has increased the inclination toward hair transplantation. To calculate the optimum density of hair follicles needed covering both the hairless area and the safe donor area (SDA), 119 male patients with AGA were recruited into this multicenter investigation. We evaluated the mean diameter and the number of hair follicles (HFs) and follicular units (FUs) in the SDA of AGA. The mean density of HFs was 137.45 ± 30.11 hair/cm² and the FUs was 76.82 ± 12.09 FUs/cm². The mean diameter of the hair was 0.97 ± 0.01 mm in the SDA. We obtained the decisive factors in the restoration of the scalp by building a geometric model and summarizing it in a new formula. This study showed that the length and direction of the hair play a vital role in restoring the bald area with hair transplantation. The density of 55.00 ± 10.00 hair/cm² (30.00 ± 5.00 FUs/cm²) for the transplanted area and no less than 106.88 hair/cm² (60.00 FUs/cm²) for SDA is regarded as an optimum parameter for hair transplantation of AGA.

Platelet-rich plasma and regenerative dentistry

Regenerative dentistry is an emerging field of medicine involving stem cell technology, tissue engineering and dental science. It exploits biological mechanisms to regenerate damaged oral tissues and restore their functions. Platelet‐rich plasma (PRP) is a biological product that is defined as the portion of plasma fraction of autologous blood with a platelet concentration above that of the original whole blood. A super‐mixture of key cytokines and growth factors is present in platelet granules. Thus, the application of PRP has gained unprecedented attention in regenerative medicine. The rationale underlies the utilization of PRP is that it acts as a biomaterial to deliver critical growth factors and cytokines from platelet granules to the targeted area, thus promoting regeneration in a variety of tissues. Based on enhanced understanding of cell signalling and growth factor biology, researchers have begun to use PRP treatment as a novel method to regenerate damaged tissues, including liver, bone, cartilage, tendon and dental pulp. To enable better understanding of the regenerative effects of PRP in dentistry, this review describes different methods of preparation and application of this biological product, and provides detailed explanations of the controversies and future prospects related to the use of PRP in dental regenerative medicine.

Comparison of platelet-rich fibrin (PRF) produced using 3 commercially available centrifuges at both high (~ 700 g) and low (~ 200 g) relative centrifugation forces

OBJECTIVES

Platelet-rich fibrin (PRF) has gained tremendous momentum in recent years as a natural autologous growth factor derived from blood capable of stimulating tissue regeneration. Owing to its widespread use, many companies have commercialized various centrifugation devices with various proposed protocols. The aim of the present study was to compare 3 different commercially available centrifuges at both high and low g-force protocols.

MATERIALS AND METHODS

PRF was produced on three commercially available centrifuges including the IntraSpin Device (IntraLock), the Duo Quattro (Process for PRF), and Salvin (Salvin Dental). Two separate protocols were tested on each machine including the original leukocyte and platelet-rich fibrin (L-PRF) protocol (~ 700 RCF max (~ 400 RCF clot) for 12 min) as well as the advanced platelet-rich fibrin (A-PRF+) protocol (~ 200 g RCF max (~ 130 g RCF clot) for 8 min). Each of the tested groups was compared for cell numbers, growth factor release, scanning electron microscopy (SEM) for morphological differences, and clot size (both weight and length/width).

RESULTS

The present study found that PRF clots produced utilizing the low-speed centrifugation speeds (~ 200 g for 8 min) produce clots that (1) contained a higher concentration of evenly distributed platelets, (2) secreted higher concentrations of growth factors over a 10 day period, and (3) were smaller in size. This was irrespective of the centrifugation device utilized and consistently observed on all 3 devices. The greatest impact was found between the protocols utilized (up to a 200%). Interestingly, it was further revealed that the centrifugation tubes used had a much greater impact on the final size outcome of PRF clots when compared to centrifugation devices. It was found that, in general, the Process for PRF tubes produced significantly greater-sized clots when compared to other commercially available tubes. The Salvin Dental tubes also produced significantly greater PRF clots when compared to the IntraLock tubes on each of the tested centrifugation devices.

CONCLUSIONS

The present study demonstrated the reproducibility of a scientific concept (reduction in RCF produces PRF clots with more evenly distributed cells and growth factors) utilizing different devices. Furthermore, (and until now overlooked), it was revealed for the first time that the centrifugation tubes are central to the quality production of PRF. Future research investigating tube characteristics thus becomes critically important for the future optimization of PRF.

CLINICAL RELEVANCE

This is the first study to reveal the marked impact of centrifugation tubes on the final production of PRF. Future study thus becomes markedly important to further optimize the quality of PRF-based matrices. It was further found that little variability existed between the centrifugation devices if optimized centrifugation protocols (lower centrifugation speeds) were utilized.

A novel method for harvesting concentrated platelet-rich fibrin (C-PRF) with a 10-fold increase in platelet and leukocyte yields

BACKGROUND AND OBJECTIVES

Liquid platelet rich fibrin (PRF; often referred to as injectable PRF) has been utilized as an injectable formulation of PRF that is capable of stimulating tissue regeneration. Our research group recently found that following standard L-PRF protocols (2700 RPM for 12 min), a massive increase in platelets and leukocytes was observed directly within the buffy-coat layer directly above the red blood cell layer. The purpose of this study was to develop a novel harvesting technique to isolate liquid PRF directly from this buffy coat layer and to compare this technique to standard i-PRF.

MATERIALS AND METHODS

Standard high g-force L-PRF and low g-force i-PRF protocols were utilized to separate blood layers. Above the red blood corpuscle layer, sequential 100-μL layers of plasma were harvested (12 layers total; i.e., 1.2 mL, which represents the total i-PRF volume), and 3 layers (3 × 100 μL) were harvested from the red blood cell layer to quantify blood cells. Each layer was then sent for complete blood count (CBC) analysis, and the cell numbers were quantified including red blood cells, leukocytes, neutrophils, lymphocytes, monocytes, and platelets. The liquid PRF that was directly collected from the buffy-coat layer following L-PRF protocols was referred to as concentrated PRF (C-PRF).

RESULTS

The i-PRF protocol typically yielded a 2- to 3-fold increase in platelets and a l.5-fold increase in leukocyte concentration from the 1- to 1.2-mL plasma layer compared to baseline concentrations in whole blood. While almost no cells were found in the first 4-mL layer of L-PRF, a massive accumulation of platelets and leukocytes was found directly within the buffy coat layer demonstrating extremely high concentrations of cells in this 0.3-0.5-mL layer (~ 20-fold increases). We therefore proposed harvesting this 0.3- to 0.5-mL layer directly above the red blood cell corpuscle layer as liquid C-PRF. In general, i-PRF was able to increase platelet numbers by ~ 250%, whereas a 1200-1700% increase in platelet numbers could easily be achieved by harvesting this 0.3-0.5 mL of C-PRF (total platelet concentrations of > 2000-3000 × 10⁹ cells/L).

CONCLUSION

While conventional i-PRF protocols increase platelet yield by 2-3-fold and leukocyte yield by 50%, we convincingly demonstrated the ability to concentrate platelets and leukocytes over 10-fold by harvesting the 0.3-0.5 mL of C-PRF within the buffy coat following L-PRF protocols.

CLINICAL RELEVANCE

Previous studies have demonstrated only a slight increase in platelet and leukocyte concentrations in i-PRF. The present study described a novel harvesting technique with over a 10-fold increase in platelets and leukocytes that can be further utilized for tissue regeneration.

Platelet-rich plasma activates AKT signaling to promote wound healing in a mouse model of radiation-induced skin injury

Background

The skin is impacted by every form of external radiation therapy. However, effective therapeutic options for severe, acute radiation-induced skin reactions are limited. Although platelet-rich plasma (PRP) is known to improve cutaneous wound healing, its effects in the context of high-dose irradiation are still poorly understood.

Methods

We investigated the regenerative functions of PRP by subjecting the dorsal skin of mice to local irradiation (40 Gy) and exposing HaCaT cells to gamma rays (5 Gy). The cutaneous benefits of PRP were gauged by wound size, histologic features, immunostains, western blot, and transepithelial water loss (TEWL). To assess the molecular effects of PRP on keratinocytes of healing radiation-induced wounds, we evaluated AKT signaling.

Results

Heightened expression of keratin 14 (K14) was documented in irradiated HaCaT cells and skin tissue, although the healing capacity of injured HaCaT cells declined. By applying PRP, this capacity was restored via augmented AKT signaling. In our mouse model, PRP use achieved the following: (1) healing of desquamated skin, acutely injured by radiation; (2) activated AKT signaling, improving migration and proliferation of K14 cells; (3) greater expression of involucrin in keratin 10 cells and sebaceous glands; and (4) reduced TEWL, strengthening the cutaneous barrier function.

Conclusions

Our findings indicate that PRP enhances the functions of K14 cells via AKT signaling, accelerating the regeneration of irradiated skin. These wound-healing benefits may have merit in a clinical setting.

Effect of Liquid Platelet-rich Fibrin and Platelet-rich Plasma on the Regenerative Potential of Dental Pulp Cells Cultured under Inflammatory Conditions: A Comparative Analysis

INTRODUCTION

Platelet-rich plasma (PRP) has been widely used in regenerative dentistry for over 2 decades. Nevertheless, previous studies have shown that its growth factor content is released over a short time period, and the application of anticoagulants limits its regenerative potential. Therefore, a second-generation platelet concentrate (liquid platelet-rich fibrin [PRF]) was developed without the use of anticoagulants and with shorter centrifugation times. The purpose of the present study was to compare the cellular regenerative activity of human dental pulp cells (hDPCs) when cultured with either liquid PRF or traditional PRP.

METHODS

The regenerative potential of hDPCs isolated from healthy human third molars (18-22 years, n = 5) was investigated in both normal and inflammatorylike conditions (lipopolysaccharide [LPS]) and assessed for their potential for dentin repair. The effects of liquid PRF and PRP were assessed for cellular migration, proliferation, and odontoblastic differentiation using a transwell assay, scratch assay, proliferation assay, alkaline phosphatase assay, alizarin red staining, and real-time polymerase chain reaction for genes encoding collagen type 1 alpha 1, dentin sialophosphoprotein, and dentin matrix protein 1, respectively. The effects of both platelet concentrates were also assessed for their ability to influence nuclear translocation of nuclear factor kappa B (p65) by immunofluorescence, and reverse-transcription polymerase chain reaction for genes encoding interleukin-1β, tumor necrosis factor alpha, and nuclear factor kappa B (p65) during an inflammatory condition.

RESULTS

Both PRP and liquid PRF increased the migration and proliferation of hDPCs when compared with the control group, whereas liquid PRF showed a notable significant increase in migration when compared with PRP. Furthermore, liquid PRF induced significantly greater alkaline phosphatase activity, alizarin red staining, and a messenger RNA expression of genes encoding collagen type 1 alpha 1, dentin sialophosphoprotein, and dentin matrix protein 1 when compared with PRP. When hDPCs were cultured with LPS to stimulate an inflammatory environment, a marked decrease in dentin-related repair was observed. When liquid PRF was cultured within this inflammatory environment, the reduced regenerative potential in this LPS-produced environment was significantly and markedly improved, facilitating hDPC regeneration. The messenger RNA expression of inflammatory markers including tumor necrosis factor alpha, interleukin-1β, and p65 were all significantly decreased in the presence of liquid PRF, and, furthermore, liquid PRF also inhibited the transport of p65 to the nucleus in hDPCs (suggesting a reduced inflammatory condition).

CONCLUSIONS

The findings from the present study suggest that liquid PRF promoted greater regeneration potential of hDPCs when compared with traditional PRP. Furthermore, liquid PRF also attenuated the inflammatory condition created by LPS and maintained a supportive regenerative ability for the stimulation of odontoblastic differentiation and reparative dentin in hDPCs.

Platelet-rich plasma as a site-targeted approach in wound healing: a molecular perspective

Wound healing remained an equation with multiple variables that experts in the medical field are trying to solve. The need to find an adjuvant that can quicken the healing process is increasing with every day, as longer wound healing times raise the risk of infections. Platelet-rich plasma is a promising tool promoting faster healing in a variety of wounds (thermal wounds, burn wounds, surgeries, etc.), as a series of studies present encouraging results in patients that received platelet-rich plasma treatment. The aim of this paper is to review and comment on the useful benefits and limitations of using platelet-rich plasma as an adjuvant strategy in wound healing, emphasizing on skin related wounds.

Platelet rich plasma for the management of hair loss: Better alone or in combination?

Platelet-rich plasma (PRP) and autologous protein-based treatments have recently emerged as a potential therapeutic approach for hair loss-related disorders including androgenetic alopecia and alopecia areata. The safety and efficacy of repeated intradermal injections of PRP has proved to promote hair growth in a number of randomized clinical trials. Biologically active proteins and cytokines released upon platelet activation have shown to induce folliculogenesis and activate the anagen growing phase of dormant bulbs. Interestingly, further studies have revealed that combining PRP with other hair loss-related products may enhance the final performance of the treatment. These synergistic approaches include Food and Drug Administration (FDA) approved drugs such as finasteride or minoxidil, bioactive macromolecules and cell-based therapies. Here, recent research involving alone or combined therapy with platelet-rich plasma for the management of hair loss-related disorders are outlined and future prospects are discussed.

Photobiomodulation therapy for androgenetic alopecia: A clinician's guide to home-use devices cleared by the Federal Drug Administration

The market for home-use photobiomodulation devices to treat androgenetic alopecia has rapidly expanded, and the Food and Drug Administration (FDA) has recently cleared many devices for this purpose. Patients increasingly seek the advice of dermatologists regarding the safety and efficacy of these hair loss treatments. The purpose of this guide was threefold: (1) to identify all home-use photobiomodulation therapy devices with FDA-clearance for treatment of androgenetic alopecia; (2) to review device design, features and existing clinical evidence; and (3) to discuss practical considerations of photobiomodulation therapy, including patient suitability, treatment goals, safety, and device selection. A search of the FDA 510(k) Premarket Notification database was conducted using product code "OAP" to identify all home-use devices that are FDA-cleared to treat androgenetic alopecia. Thirteen commercially available devices were identified and compared. Devices varied in shape, wavelength, light sources, technical features, price, and level of clinical evidence. To date, there are no head-to-head studies comparing the efficacy of these devices. Photobiomodulation therapy devices have an excellent safety profile and mounting evidence supporting their efficacy. However, long-term, high quality studies comparing these devices in diverse populations are lacking. As these devices become increasingly popular, dermatologists should be familiar with this treatment modality to add to their therapeutic armamentarium.

ABBREVIATIONS

AGA, androgenetic alopecia; FDA, Food and Drug Administration; IEC, International Electrotechnical Commission; LED, light-emitting diode; PBMT, photobiomodulation therapy.

Opening new horizons in regenerative dermatology using platelet-based autologous therapies

Biological therapeutic therapies are gaining the attention of scientists and medical doctors. Accumulating evidence suggests that blood-derived autologous therapies are safe and effective treatments for skin repair and wound healing. The fibrin network formed after plasmatic activation and the autologous growth factors released when platelets degranulate constitute a real biological medicine that has been shown to promote cell recruitment, stimulate new blood vessel formation, reduce inflammation as well as protect from local infections. This perspective highlights recent basic and clinical results published on blood-derived autologous therapies in the field of regenerative dermatology and discusses potential challenges and future prospects.

Behavior of Gingival Fibroblasts on Titanium Implant Surfaces in Combination with either Injectable-PRF or PRP

Various strategies have been employed to speed tissue regeneration using bioactive molecules. Interestingly, platelet concentrates derived from a patient's own blood have been utilized as a regenerative strategy in recent years. In the present study, a novel liquid platelet formulation prepared without the use of anti-coagulants (injectable-platelet-rich fibrin, i-PRF) was compared to standard platelet-rich plasma (PRP) with gingival fibroblasts cultured on smooth and roughened titanium implant surfaces. Standard PRP and i-PRF (centrifuged at 700 rpm (60× g) for 3 min) were compared by assays for fibroblast biocompatibility, migration, adhesion, proliferation, as well as expression of platelet-derived growth factor (PDGF), transforming growth factor-β (TGF-β), collagen1 (COL1) and fibronectin (FN). The results demonstrate that i-PRF induced significantly higher cell migration, as well as higher messenger RNA (mRNA) levels of PDGF, TGF-β, collagen1 and fibronectin when compared to PRP. Furthermore, collagen1 synthesis was highest in the i-PRF group. These findings demonstrate that liquid platelet concentrates can be formulated without the use of anticoagulants and present much translational potential for future research. Future animal and clinical trials are now necessary to further investigate the potential of utilizing i-PRF for soft tissue regenerative protocols in combination with various biomaterials.