Principles and Methods of Preparation of Platelet-Rich Plasma: A Review and Author's Perspective

Platelet-Rich Plasma as an Orthobiologic: Clinically Relevant Considerations

Platelet-rich plasma (PRP) is an autologous blood-derived product processed to concentrate platelets and the associated growth factors. PRP has been shown to be relatively well-tolerated and safe to use for a number of conditions in humans, equines, and canines. There are multiple commercial systems that have been validated for canine use. These systems use a variety of methodologies to produce a PRP product. However, PRP products have been shown to differ greatly between systems. Further study is needed to fully elucidate optimal component concentrations for various indications.

Efficacy of autologous platelet-rich plasma in the treatment of vitiligo : A 10- patient prospective study

INTRODUCTION

Vitiligo is an autoimmune disorder characterised by loss of epidermal melanocytes. It has cosmetic and psychosocial impact. The objective of this paper is to evaluate the interest of platelet-rich-plasma (PRP) in the treatment of vitiligo.

MATERIAL AND METHODS

We conducted a prospective study between January 2019 to September 2021.

RESULTS

Our descriptive study included 10 patients followed-up for vitiligo refractory to conventional therapies. The mean age was 36,2 years. Sex ratio was 0,25. Prior to PRP treatment, vitiligo was stable in all cases. The mean number of PRP sessions received by our patients was 2,6 (1-6). A visible improvement of lesions was obtained after a mean of 1,5 sessions. 40% of patients had obtained repigmentation of more than 50% for at least one lesion. An improvement of more than 75% (grade 4) was noted in 2 cases after a mean duration of 5,5 sessions. 40% of patients had obtained repigmentation of more than 50% for at least one lesion. A percentage of improvement between 50 and 74% (grade 3) was obtained for 2 patients. Four patients had an improvement of less than 25% (grade 1) after a mean of 1,75 sessions. There was no recurrence of depigmentation after a mean follow-up of 6 months (1 to 24 months).

CONCLUSION

Our series proves the benefit of PRP in the treatment of vitiligo. It is a safe and promising option for stable lesions in different body sites with few side effects.

Autologous lipoaspirate as a new treatment of vulvar lichen sclerosus: A review on literature

Lichen sclerosus (LS) is a chronic inflammatory dermatosis that mostly affects the genital and anal skin areas. Symptoms may vary from pruritis and pain to sexual dysfunction; however, LS can also be asymptomatic. LS occurs at all ages and in both sexes. Approximately 5% of all women affected by vulvar LS will develop vulvar squamous cell carcinoma. Topical treatment is safe but less effective resulting in chronic course in most patients, who suffer from persistent itching and pain. In severe cases of therapy-resistant LS, there is no adequate treatment. Fat grafting is a novel regenerative therapy to reduce dermal fibrosis. The therapeutic effect of adipose tissue grafts for LS is already investigated in various pioneering studies. This review provides an overview of these studies and the putative mechanisms-of-action of fat grafting to treat LS.

Hamizul MHA, Khairul Bariah AAN, Wan Kamarul Zaman WS, Nordin F. Regenerative Medicine Therapy in Malaysia: An Update

Regenerative medicine is a field in medicine that relates to the ability to correct congenital anomalies and to repair or replace tissues and organs that have been destroyed by age, disease, or trauma. To date, promising preclinical and clinical data supported the possibility of using regenerative medicine to treat both chronic diseases and acute insults, as well as maladies affecting a wide range of organ systems and contexts, such as dermal wounds, cardiovascular diseases and traumas, cancer treatments, and more. One of the regenerative medicine therapies that have been used widely is stem cells. Stem cells, especially mesenchymal and hematopoietic stem cells, play an important role in treating chronic diseases, such as leukemia, bone marrow, autoimmune disease, and urinary problems. Despite considerable advancements in stem cell biology, their applications are limited by ethical concerns about embryonic stem cells, tumor development, and rejection. Nevertheless, many of these constraints, are being overcome, which could lead to significant advancements in disease management. This review discusses the current developments and advancements of regenerative medicine therapy (RMT) advancements in Malaysia compared to other Asian countries. The limitations in the application of RMT are also highlighted.

Comparison of the effect on the ovarian reserve of modern methods of treatment of endometrioid cysts

OBJECTIVE

To compare the efficacy and safety of autologous platelet-rich plasma (PRP) therapy in laparoscopy and transvaginal sclerotherapy for the treatment of endometrioid cysts for maintaining ovarian reserve.

METHODS

The study included 71 women under age 35 years with primary and secondary infertility. Twenty women underwent sclerotherapy of endometrioid cysts followed by autologous PRP injection into ovarian tissue, and 21 underwent laparoscopic cyst removal by stripping followed by autologous PRP injection. The control group consisted of 30 women who underwent laparoscopic cystectomy by stripping without autologous PRP injection. We assessed ovarian reserve for all patients before surgery as well 3 and 6 months after surgery by measuring serum anti-Müllerian hormone (AMH) levels and calculating antral follicle count using ultrasound.

RESULTS

In the control group, AMH levels had decreased significantly at 3 and 6 months post-surgery, whereas levels in laparoscopy and PRP group remained almost unchanged from initial levels. In the sclerotherapy group, we observed a tendency towards increased AMH levels, but it was not statistically significant when compared with initial results. Follicle count changes were similar to AMH patterns.

CONCLUSION

In this study, sclerotherapy in combination with PRP therapy for ovarian endometriomas was associated with improved measures of ovarian reserve, and the combination of laparoscopic excision of the endometrioma with PRP therapy facilitated ovarian reserve preservation.

Evaluation of a Standardized Protocol for Plasma Rich in Growth Factors Obtention in Cats: A Prospective Study

Introduction

Platelet-rich plasma (PRP) is an autologous plasma with platelet (PLT) concentration above that of whole blood (WB). PLTs contain growth factors (GFs) that promote tissular repair.

Objectives

To determine and compare the concentrations of PLT, red blood cells (RBC) and white blood cells (WBC) between WB samples, PRP and platelet poor plasma (PPP) samples; and to analyze the concentrations of platelet-derived growth factor BB (PDGF-BB) and transforming growth factor β1 (TGF-β1) in the PRP and PPP of healthy adult cats using a standardized protocol with PRGF®-Endoret® characteristics.

Material and Methods

WB was collected from 30 cats. PRP was obtained following three centrifugation protocols using PRGF®-Endoret® technology: 255, 260, and 265 g for 10 min each. The cellular components, RBC, WBC, PLT, and the concentrations of PDGF-BB and TGF-β1 in the PRP and PPP fractions were determined for each protocol.

Results

PLTs in the PRP fraction were statistically higher than WB, with no statistical differences between PPP and WB. In PRP fraction, PLT concentration was increased 1.4 times on average at 255 g; 1.3 times at 260 g and, 1.5 times at 265 g without statistical differences among them. The mean platelet volume (MPV) was significantly higher in WB compared to PRP and PPP fractions without significant differences between protocols. Compared to WB, the number of RBCs and WBCs was reduced by 99% and by more than 95% in PRP and PPP respectively, without significant differences between protocols. PDGF-BB concentrations were statistically higher in PRP than in PPP fractions, however, TGF-ß1 concentrations did not vary between fractions at 260 g. Comparing the three protocols within PRP and PPP fractions, no differences in PDGF-BB and TGF-ß1 concentrations were observed.

Clinical Relevance

The study shows scientific evidence regarding the obtention of PRP in cats using the PRGF®-Endoret® technology for the quantification of PDGF-BB and TGF-ß1. At 265 g for 10 min, PLT concentration was increased 1.5 times with unnoticeable erythrocytes and leukocytes in the samples. These results clearly show that the PRGF®-Endoret® methodology is suitable to obtain PRP in cats. Further studies are needed to determine the clinical efficacy of the obtained PGRF in the treatment of different pathologies in cats.

PRP Versus Standard of Care for Venous leg Ulcers: A Systematic Review and Meta-Analysis of Prospective Comparative Studies

Venous leg ulcers (VLUs) are chronic and recalcitrant lower limb wounds that affect millions of patients annually, severely reducing their quality of life, and causing a significant burden on the health care system. Recently, Platelet rich plasma (PRP) has been used to improve healing of VLUs. This systematic review aimed at evaluating the effectiveness of PRP versus the standard of care commonly used to treat VLUs. Ten prospective studies (8 randomized) met the inclusion criteria comprising 451 patients with 527 VLUs. Results were as follows: a) the weighted Odds Ratio (OR) of the mean healing rate was 2.84 (95% CI = 1.160 to 5.056, I2 = 41.4%, p = 0.0004), b) the mean healed ulcer areas were 79.2 ± 19% for the PRP group and 51.7 ± 36% for the control group (p = 0.007) in favor of the PRP group, and c) the weighted infection OR showed no significant difference between both groups. Additionally, negative correlations were found between healing rate and duration of VLUs and initial size of the ulcers. This meta-analysis demonstrated significant beneficial effects of PRP versus standard of care on healing rate, reduction in surface, and reduction in healing time of VLUs. Infection and other complications were similar to standard of care. Therefore, our analytical data would support the use of PRP as a safe and effective treatment for VLUs.

Evaluation of the safety and efficacy of platelet-rich plasma in the treatment of female patients with chronic telogen effluvium: A randomised, controlled, double-blind, pilot clinical trial

BACKGROUND

Chronic telogen effluvium is characterised by diffuse loss of hair of the scalp. One of the emerging lines of treatment is platelet-rich plasma. However, not much of published data exist.

AIMS

A pilot study was conducted on chronic telogen effluvium patients to evaluate the efficacy and safety of platelet-rich plasma, and to compare two different methods of platelet-rich plasma preparation.

METHODS

The study included 30 female patients with chronic telogen effluvium. Patients were randomised into three groups: Group (1): Special platelet-rich plasma tubes centrifuged at 3500 rpm; Group (2): Ordinary laboratory tubes centrifuged at 1000 rpm; Group (3): Normal saline as a placebo. Patients' evaluation was done with visual analog scale, hair pull test, trichoscopy, photos, satisfaction questionnaire, and safety. All patients received four monthly sessions. Patients were evaluated one month and three months after the last session.

RESULTS

The hair pull test,visual analogue scale, and patient satisfaction results showed a statistically significant difference between group 1 vs. group 3 and group 2 vs.group 3 at one and three months after the sessions, while there was no difference between group1 vs. group 2. Trichoscopy results (baseline, one and three months after treatment) showed a significant increase in hair density and thickness in the frontal area, temporal area, and the vertex in groups 1 and 2 only. There was no statistically significant difference between the three groups with regards to side effects.

LIMITATIONS

The sample size was small with ten patients in each group. Furthermore, the follow-up of patients was for only three months.

CONCLUSIONS

Platelet-rich plasma could be considered as a promising therapy for patients with chronic telogen effluvium with an excellent safety profile. The ordinary laboratory low-cost tubes might be a reliable alternative to the expensive special platelet-rich plasma kits tubes. The trial registry number is PACTR202006539654415.

Treatment of Androgenetic Alopecia Using PRP to Target Dysregulated Mechanisms and Pathways

Androgenetic alopecia (“AGA”) is the most prevalent type of progressive hair loss, causing tremendous psychological and social stress in patients. However, AGA treatment remains limited in scope. The pathogenesis of androgenetic alopecia is not completely understood but is known to involve a hair follicle miniaturization process in which terminal hair is transformed into thinner, softer vellus-like hair. This process is related to the dysregulation of the Wnt/β-catenin signaling pathway, which causes premature termination of the anagen growth phase in hair follicles. Historically used for wound healing, platelet rich plasma (“PRP”) has recently been at the forefront of potential AGA treatment. PRP is an autologous preparation of plasma that contains a high number of platelets and their associated growth factors such as EGF, IGF-1, and VEGF. These factors are known to individually play important roles in regulating hair follicle growth. However, the clinical effectiveness of PRP is often difficult to characterize and summarize as there are wide variabilities in the PRP preparation and administration protocols with no consensus on which protocol provides the best results. This study follows the previous review from our group in 2018 by Cervantes et al. to analyze and discuss recent clinical trials using PRP for the treatment of AGA. In contrast to our previous publication, we include recent clinical trials that assessed PRP in combination or in direct comparison with standard of care procedures for AGA such as topical minoxidil and/or oral finasteride. Overall, this study aims to provide an in-depth analysis of PRP in the treatment of AGA based on the evaluation of 17 recent clinical trials published between 2018 and October 2021. By closely examining the methodologies of each clinical trial included in our study, we additionally aim to provide an overall consensus on how PRP can be best utilized for the treatment of AGA.

Ovarian reserve parameters and IVF outcomes in 510 women with poor ovarian response (POR) treated with intraovarian injection of autologous platelet rich plasma (PRP)

The aim of the current study was to characterize ovarian reserve parameters and IVF outcomes in women with a history of poor ovarian response (POR) treated with intraovarian injection of autologous platelet rich plasma (PRP). Reproductive age women (N=510; age range 30-45yo) diagnosed with POR based on Poseidon criteria were included in the study. PRP treatment resulted in higher AFC, higher serum AMH, lower serum FSH, and a higher number of mature oocytes and cleavage and blastocyst stage embryos. After PRP injection, 22 women (4.3%) conceived spontaneously, 14 (2.7%) were lost to follow up, and 474 (92.9%) attempted IVF. Among women who attempted IVF, 312 (65.8%) generated embryos and underwent embryo transfer, 83 (17.5%) achieved a pregnancy, and 54 (11.4%) achieved sustained implantation/live birth (SI/LB). In total, of the 510 women with POR and mean age of 40.3, PRP resulted in improvement of ovarian reserve parameters, a pregnancy rate of 20.5% and SI/LB rate of 12.9%. Our findings suggest that PRP treatment may be considered in women with POR. For wider clinical application, its clinical efficacy will need to be demonstrated in prospective randomized clinical trials.

Profiling the Murine Acute Phase and Inflammatory Responses to African Snake Venom: An Approach to Inform Acute Snakebite Pathology

Snake envenoming causes rapid systemic and local effects that often result in fatal or long-term disability outcomes. It seems likely that acute phase and inflammatory responses contribute to these haemorrhagic, coagulopathic, neurotoxic, nephrotoxic and local tissue destructive pathologies. However, the contributory role of acute phase/inflammatory responses to envenoming is under-researched and poorly understood—particularly for envenoming by sub-Saharan African venomous snakes. To provide data to help guide future studies of human patients, and to explore the rationale for adjunct anti-inflammatory medication, here we used an in vivo murine model to systematically assess acute phase and inflammatory responses of mice to ten African snake venoms. In addition to investigating snake species-specific effects of venom on the cardiovascular system and other key organs and tissues, we examined the response to intravascular envenoming by acute phase reactants, including serum amyloid A, P-selectin and haptoglobin, and several cytokines. Venoms of the spitting (Naja nigricollis) and forest (N. melanoleuca) cobras resulted in higher acute phase and inflammatory responses than venoms from the other cobras, mambas and vipers tested. Naja nigricollis venom also stimulated a 100-fold increase in systemic interleukin 6. Thin blood films from venom-treated mice revealed species-specific changes in red blood cell morphology, indicative of membrane abnormalities and functional damage, lymphopenia and neutrophil leukocytosis. Our ex vivo assays with healthy human blood treated with these venoms identified that N. nigricollis venom induced marked levels of haemolysis and platelet aggregation. We conclude that African snake venoms stimulate very diverse responses in this mouse model of acute systemic envenoming, and that venoms of the African cobras N. nigricollis and N. melanoleuca, in particular, cause marked inflammatory and non-specific acute phase responses. We also report that several African snake venoms cause haemolytic changes. These findings emphasise the importance of understanding acute responses to envenoming, and that further research in this area may facilitate new diagnostic and treatment approaches, which in turn may lead to better clinical outcomes for snakebite patients.

Platelet Rich Plasma and Its Use in Hair Regrowth: A Review

Platelet rich plasma (PRP) was described as a small volume of plasma containing higher concentrations of platelets than those found in peripheral blood and initially used as a transfusion product for treatment of thrombocytopenia. To date, it was discovered that there are several growth factors and cytokines that can accelerate wound healing and tissue regeneration, leading to a wider range of applications in the medical field, such as in sport medicine, regenerative medicine, and aesthetic medicine. Several studies have shown that PRP can be used effectively for treatment of hair loss. Although it has been widely used, the exact mechanism of action of PRP is still not fully elucidated. In this article, we aim to review and update current information on the definition, classification, mechanism of action, clinical efficacy in hair regrowth, and adverse events of PRP.

Autologous platelet gel improves outcomes in tubularized incised plate repair of hypospadias

BACKGROUND

hypospadias is one of the most widespread male congenital anomalies, occurring in 1:250 to 1:300 live births. Several repair techniques have been developing to improve the outcomes.

PURPOSE

a randomized prospective controlled study was adopted to evaluate effectiveness of autologous platelet gel in healing promotion and improving the outcomes of hypospadias repair.

METHODS

thirty children who aged between 6 months and 12 years were recruited and subdivided into two groups; group A had tubularized incised plate (TIP) repair with autologous platelet gel application and group B had TIP repair without autologous platelet gel.

RESULTS

there was no significant difference in duration of operation between both groups. All patients in groups A and B had slit-like meatus shape in the distal glans. While all those of group A had one urine stream, yet only 11 of group B had one. There were complications that happened exclusively in group B such as spray stream (27%) and fistula (20%). Whereas other complications occurred insignificantly more in group B than in A including meatal stenosis (53 versus 27%), glans dehiscence, (20 versus 7%), bleeding (33 versus 13%), infection (33 versus 27%), edema (27% versus13), respectively. The incidence of skin necrosis was equal in both groups.

CONCLUSION

autologous platelet gel usage in TIP hypospadias repair can be a reliable technique to promote wound healing, and to limit of postoperative surgical complications.

Complementary roles of serotonergic and cholinergic systems in decisions about when to act

Decision-making not only involves deciding about which action to choose but when and whether to initiate an action in the first place. Macaque monkeys tracked number of dots on a screen and could choose when to make a response. The longer the animals waited before responding, the more dots appeared on the screen and the higher the probability of reward. Monkeys waited longer before making a response when a trial’s value was less than the environment’s average value. Recordings of brain activity with fMRI revealed that activity in dorsal raphe nucleus (DRN)—a key source of serotonin (5-HT)—tracked average value of the environment. By contrast, activity in the basal forebrain (BF)—an important source of acetylcholine (ACh)—was related to decision time to act as a function of immediate and recent past context. Interactions between DRN and BF and the anterior cingulate cortex (ACC), another region with action initiation-related activity, occurred as a function of the decision time to act. Next, we performed two psychopharmacological studies. Manipulating systemic 5-HT by citalopram prolonged the time macaques waited to respond for a given opportunity. This effect was more evident during blocks with long inter-trial intervals (ITIs) where good opportunities were sparse. Manipulating systemic acetylcholine (ACh) by rivastigmine reduced the time macaques waited to respond given the immediate and recent past context, a pattern opposite to the effect observed with 5-HT. These findings suggest complementary roles for serotonin/DRN and acetylcholine/BF in decisions about when to initiate an action.

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Both immediate context and wider environment influence decisions about when to act

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DRN and 5-HT mediate the influence of wider environment

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BF and ACh mediate the influence of immediate context

Human platelet lysates stimulate in vitro proliferation of human endometrial cells from patients with a history of recurrent implantation failure

OBJECTIVE

To optimize and compare the isolation of platelet-rich plasma (PRP) and its cryopreserved derivative, platelet lysate (PL), to a commercial human platelet lysate (HPL) product PLUS and investigate their proliferative stimulation on primary human endometrial cells in vitro.

DESIGN

Basic research.

SETTING

Academic fertility center.

PATIENT(S)

Three healthy blood donors and eight patients with a history of recurrent implantation failure.

INTERVENTIONS(S)

Stimulated proliferation of isolated primary endometrial epithelial cells and endometrial stromal cells in vitro with autologous and nonautologous HPL (PLUS; Compass Biomedical).

MAIN OUTCOME MEASURE(S)

Platelet-derived growth factor BB homodimer protein content in isolated PRP/PL and commercial HPL and endometrial epithelial cell and endometrial stromal cell proliferation after 24- or 48-hour stimulation with PL (measured by metabolic activity and Ki67 expression).

RESULT(S)

To optimize and compare the isolation of autologous PRP/PL, three double-centrifugation protocols were assessed by flow cytometry for platelet yield (CD45^-CD41⁺CD61⁺) and platelet-derived growth factor BB homodimer protein content by enzyme-linked immunosorbent assay. Cryopreserved PL, especially isolated by our fastest protocol, contained higher protein concentrations and, thus, was optimal for experimental flexibility compared with fresh PRP. The autologous and commercial PLs displayed comparable immune and growth factor content and stimulation of cell proliferation in vitro.

CONCLUSION(S)

Our results provide the groundwork for the isolation and use of HPL to stimulate endometrial growth. Furthermore, commercial PL consistently stimulated cell proliferation and may allow standardization of clinical treatment for recurrent implantation failure.

Role of Triple Injection Platelet-Rich Plasma for Osteoarthritis Knees: A 2 Years Follow-Up Study

PURPOSE

To assess the clinical outcomes of intra-articular Platelet-rich plasma (PRP) injection in knee osteoarthritis (OA) at 2 year follow-up.

METHODS

This was a prospective interventional study. 68 cases (105 knees) with Kellgren-Lawrence (KL) grades I, II and III knee OA received 3 intra-articular injections of PRP 1 month apart. The cases were followed up for 2-years. Outcomes were measured using Western Ontario and McMaster Universities Arthritis Index (WOMAC) score and Visual analog scale (VAS) scores.

RESULTS

The mean age was 51.7 years. 18 knees had KL grade I, 55 had grade II and 32 had grade III OA. The mean pre-treatment VAS score decreased significantly at 1 year (mean difference - 5.3, p = 0.003) and 2 year follow-up (mean difference - 6, p = 0.007). The mean pre-treatment WOMAC score decreased significantly at 1 year (mean difference - 45.9, p = 0.011) and at 2 year (mean difference - 52.4, p = 0.009). The WOMAC and VAS scores improved significantly from baseline to final follow-up across all KL grades (p = 0.001 and 0.001, 0.009 and 0.007, 0.021 and 0.017 for WOMAC and VAS across KL grade I, II and III, respectively). There was no significant differences in WOMAC and VAS scores between three KL grades at final follow-up (p = 0.17 and 0.09, respectively), although the baseline scores had significant difference (p = 0.001 for both VAS and WOMAC) with worse scores in higher KL grades. The variables like age, sex, BMI, KL grade, baseline VAS and baseline WOMAC did not predict the final VAS and WOMAC scores.

CONCLUSION

Triple injection of intra-articular PRP given one month apart significantly relieves the symptoms of knee OA till 2 years in KL grade I, II and III. The improvement in symptoms at 2-year follow-up did not differ across different KL grades.

Clinical evaluation of efficacy of intralesional platelet-rich plasma injection versus 1064 nm long-pulsed Neodymium:YAG laser in the treatment of inflammatory acne vulgaris in adolescent and post-adolescent patients: a prospective randomized split-face comparative study

Large numbers of local and systemic therapies are available for acne treatment. Common oral or topical retinoids, antibiotics, or keratolytics are used but sometimes are inconvenient, and side effects caused by these conventional therapies prompted a search for effective and safe treatments. This study aimed to evaluate the efficacy of intralesional platelet-rich plasma injection versus 1064 nm long-pulsed Nd:YAG laser in the treatment of moderate inflammatory acne vulgaris in both adolescents and post-adolescent patients. This split-face comparative study was carried out on thirty patients who suffered from moderate inflammatory and non-inflammatory acne vulgaris. The patients were classified into two groups: group I: adolescent (≤ 25 years) and group II: post-adolescent (< 25 years). Each group received four sessions of intralesional PRP injection on one side of the face and a long-pulsed Nd:YAG (1064 nm) laser on the other side with 2 weeks interval. Evaluation was done by blinded dermatologists using photographs and lesions counting and by patient satisfaction. Side effects were also noted. Both groups (adolescents and post-adolescent) showed a high statistically significant improvement of inflammatory as well as non-inflammatory lesions either in PRP or Nd:YAG laser–treated side with no significant difference between the two sides. The intralesional PRP injection and 1064 nm long-pulsed Nd:YAG laser are safe and effective methods for controlling inflammatory as well as non-inflammatory acne vulgaris in both adolescents and post-adolescent patients.

Platelet-rich plasma outcomes do not correlate with patient satisfaction or perceived cost-effectiveness

BACKGROUND

As platelet-rich plasma injection for knee osteoarthritis (OA) has increased in popularity, it has become more important to assess its effectiveness and satisfaction with its use in the context of its high cost. The purpose of this study was to determine satisfaction, commercial appeal, and effectiveness of platelet-rich plasma (PRP) for the treatment of knee OA.

METHODS

A retrospective review of patients who underwent PRP injection in the knee from 2016 to 2019 was performed. Various patient-reported outcomes were collected, including: satisfaction with the PRP injection (out of 100), whether the patient would want to undergo PRP injection again, whether they would recommend the injection and whether they felt that the injection was worth the cost was collected. VAS pain scores were collected and measured out of 100. Demographics and radiographical information were obtained via chart review. Statistical analyses were conducted including descriptive statistics and binary logistic and linear regressions.

RESULTS

Overall, 114 patients were included. The mean pre-injectionpain score was 70.4, and the mean pain level decreased after injection to 36.8. Patients rated their satisfaction on average as neutral along the aforementioned continuous scale (49.2), , 50.9% stated that they would get the PRP injection again, 60.5% would recommend to a friend, and 50.9% felt the injection was worth the cost. Younger age and improved post-injection pain correlated with increasing likelihood of desiring further PRP injection.

CONCLUSIONS

Patients on average rated satisfaction slightly below average, indicating net neutrality in terms of satisfaction with their injection. Furthermore, only half of the patients indicated that it was worth the cost and that they would receive it again. Younger age and post-injection pain relief increased desire for further injection, but pain-relief did not correlate with patients saying that the injection was worth the cost.

Platelets' Role in Dentistry: From Oral Pathology to Regenerative Potential

Platelets are a cellular subgroup of elements circulating in the bloodstream, responsible for the innate immunity and repairing processes. The diseases affecting this cellular population, depending on the degree, can vary from mild to severe conditions, which have to be taken into consideration in cases of minor dental procedures. Their secretion of growth factors made them useful in the regenerative intervention. The aim of this review is to examine the platelets from biological, examining the biogenesis of the platelets and the biological role in the inflammatory and reparative processes and clinical point of view, through the platelets' pathology and their use as platelets concentrates in dental regenerative surgery.

Cytokine Profiling and Intra-Articular Injection of Autologous Platelet-Rich Plasma in Knee Osteoarthritis

Osteoarthritis (OA) is a degenerative joint disease leading to joint pain and stiffness. Due to lack of effective treatments, physical and psychological disabilities caused by OA have a detrimental impact on the patient’s quality of life. Emerging evidence suggests that intra-articular injection of platelet-rich plasma (PRP) may provide favorable results since PRP comprises not only a high level of platelets but also a huge amount of cytokines, chemokines, and growth factors. However, the precise mechanism and standardization method remain uncertain. This study aimed to examine cytokine profiling in both PRP and platelet-poor plasma (PPP) of knee OA patients and to determine the effects of PRP on OA chondrocytes and knee OA patients. PRP contained a wide variety of cytokines, chemokines, growth factors, and autologous intra-articular PRP injection resulted in favorable outcomes in knee OA patients. Significant increases in levels of IL-1, IL-2, IL-7, IL-8, IL-9, IL-12, TNF-α, IL-17, PDGF-BB, bFGF, and MIP-1β were detected in PRP compared to PPP (p < 0.001). An in vitro study showed a marked increase in proliferation in OA chondrocytes cultured with PRP, compared to PPP and fetal bovine serum (p < 0.001). In a clinical study, knee OA patients treated with PRP showed improvement of physical function and pain, assessed by physical performance, Western Ontario and McMaster Universities Arthritis Index and visual analog scale. Our findings from both in vitro and clinical studies suggest that intra-articular PRP injection in knee OA patients may be a potential therapeutic strategy for alleviating knee pain and delaying the need for surgery.

A Simple Double-Spin Closed Method for Preparing Platelet-Rich Plasma

Objective: To describe and analyze a new protocol for the extraction of platelet-rich plasma (PRP) for use in clinical practice and compare this technique with methods that have been previously described in the medical literature.

Methods: Sixteen blood samples from healthy volunteers were collected. PRP was prepared using our new double-spin technique, consisting of successive centrifugation of blood samples with two different spins, without opening the container. Descriptive analysis of cell counts in baseline and PRP samples was undertaken. Comparison between cell and platelet count in baseline and PRP samples, as well as the statistical analysis, were done.

Results: The mean platelet concentration ratio was 3.47 (SD: 0.85; 95% CI: 3.01-3.92; range: 2.48-5.71). The baseline whole blood platelet count correlated positively to the PRP platelet count (rP = 0.56; 95% CI: 0.09-0.88; P = 0.023). The PRP was enriched for lymphocytes and monocytes but presented significantly lower counts of neutrophils and eosinophils in comparison to baseline.

Conclusion: Results show a safe and easily reproducible method to obtain PRP for use in clinical daily practice.

Effect of advanced platelet-rich fibrin and concentrated growth factor on tissues around implants in maxillary anterior region

Aim

To assess the effect of advanced platelet-rich fibrin (APRF) and concentrated growth factor (CGF) on tissues around implants in the maxillary anterior region.

Settings and Design

This was a prospective clinical study.

Materials and Methods

Thirty subjects were divided into three groups with 10 dental implants in each group, i.e., Group 1: Control group, Group 2: Endosseous implant placement with APRF, and Group 3: Endosseous implant placement with CGF. The subjects were assessed at baseline (at the time of prosthesis placement), 2 weeks, 2 months, 6 months, and 1 year for modified sulcular bleeding index, periimplant probing depth, mucosal suppuration, bleeding on probing, crestal bone level as well as implant stability.

Statistical Analysis Used

Oneway Analysis of variance and Post hoc Bonferroni were the statistical tests used.

Results

The difference in implant stability at 2 months was significantly (P < 0.05) more among the control and CGF groups compared to APRF group. However; the crestal bone levels, periimplant probing depth, modified sulcular bleeding index, mucosal suppuration, and bleeding on probing were statistically non-significant (P > 0.05).

Conclusion

CGF and APRF accelerated osseointegration. Furthermore, they had a positive effect on stabilization values. However, CGF showed better results and with further clinical trials may show a positive effect on implant healing period.

Ovarian response to intraovarian platelet-rich plasma (PRP) administration: hypotheses and potential mechanisms of action

PURPOSE

Platelet-rich plasma (PRP) therapy has been used as an adjunct to fertility treatments in women with very low ovarian reserve and premature ovarian insufficiency. Recent literature in both humans and animals suggest that intraovarian PRP administration in the setting of poor ovarian reserve may help ovarian function and increase the chances of pregnancy.

METHODS

A comprehensive literature search through PubMed, MEDLINE databases, and recent abstracts published at relevant society meetings was performed and resulted in 25 articles and 2 abstracts published that studied effect of PRP on the ovaries for the purpose of reproduction.

RESULTS

This review article presents all the data published to date pertaining to intraovarian PRP injection and pregnancy, both naturally and after in vitro fertilization. It also presents the most recent data on the use of ovarian PRP in in vitro and animal model studies highlighting the possible mechanisms by which PRP could impact ovarian function.

CONCLUSIONS

Even though recent commentaries questioned the use of PRP as an "add-on" therapy in fertility treatment because it has not been thoroughly studied, the recent basic science studies presented here could increase awareness for considering more serious research into the efficacy of PRP as an adjunct for women with poor ovarian reserve, premature ovarian insufficiency, and even early menopause who are trying to conceive using their own oocytes. Given its low-risk profile, the hypothetical benefit of PRP treatment needs to be studied with larger randomized controlled trials.

Platelet concentrates in periodontics: review of in vivo studies and systematic reviews

Clot formation is the first step of the healing process, and clinical procedures always find ways to stabilize this clot better. Platelets play a significant role in clot formation, and Platelet Concentrates (Pc) are an abundant reservoir of platelets. This article aims to review the in vitro research and systematic reviews on PCs that are currently available. Broadly, PCs mainly include Platelet-rich plasma and platelet-rich fibrin. PCs are an excellent source for growth factors such as PDGF-AA, TGF β1, VEGF, EGF, and IGF. Numerous systematic reviews and meta-analyses have analyzed the clinical application of PCs in various periodontal procedures. In alveolar ridge preservation, PCs are known to reduce postoperative pain, edema, trismus, and inflammation. PRF had shown significant improvement in achieving root coverage and recession depth reduction. PCs exhibited a positive influence on CAL gain when used as an adjunct to OFD in treating infra-bony defects. Pcs have a positive effect on bone maturation in the short term. Besides, PCs can be used in regenerative endodontics, treatment of medication-related osteoradionecrosis of Jaw (MRONJ), and accelerating tooth movement. In conclusion, PCs positively affect soft tissue healing, while their role in hard tissue healing is still unclear.

The Effect of Calcium Gluconate on Platelet Rich Plasma Activation for VEGF-A Expression of Human Dental Pulp Stem Cells

Objective  Platelet-rich plasma (PRP) activation is an important factor in triggering the initial release of blood-derived growth factors from platelets. Vascular endothelial growth factor-A (VEGF-A) can be expressed by human dental pulp stem cells (hDPSCs) and plays an important role in dental pulp angiogenesis. The aim of this study is to analyze the effects of calcium gluconate on PRP activation in hDPSC VEGF-A expression.

Materials and Methods  Two types of PRP and their corresponding activators were analyzed in this study: PRP (activated using calcium chloride/CaCl ₂ ) and PRP-T (activated using CaCl ₂ with the addition of 10% calcium gluconate). hDPSCs were obtained by using an out-growth method (DPSCs-OG), and harvest between the fifth and sixth passages, then cultured in three different media groups: control, PRP, and PRP-T, which were planted in 96 wells (5 × 10 ³ each well). The VEGF-A expression of hDPSCs was analyzed by using an ELISA test and observed at 24, 48, and 72 hours.

Statistical Analysis  This study was performed by using one-way ANOVA ( p  < 0.05) test.

Results  There were significant differences between all groups ( p  < 0.05) at 48 and 72 hours of observations, and no significant differences in the PRP and PRP-T groups at 48 and 72 hours of observations ( p  > 0.05).

Conclusion  PRP and PRP-T were equally effective in inducing VEGF-A expression of hDPSCs.

Appraisal of Experimental Methods to Manage Menopause and Infertility: Intraovarian Platelet-Rich Plasma vs. Condensed Platelet-Derived Cytokines

The first published description of intraovarian platelet-rich plasma (PRP) appeared in mid-2016, when a new experimental technique was successfully used in adult human ovaries to correct the reduced fertility potential accompanying advanced maternal age. Considering the potential therapeutic scope of intraovarian PRP would likely cover both menopause and infertility, the mainstream response has ranged from skeptical disbelief to welcome astonishment. Indeed, reports of intraovarian PRP leading to restored menses in menopause (as an alternative to conventional hormone replacement therapy) and healthy term livebirths for infertility patients (from IVF or as unassisted conceptions) continue to draw notice. Yet, any proper criticism of ovarian PRP applications will be difficult to rebut given the heterogenous patient screening, varied sample preparations, wide differences in platelet incubation and activation protocols, surgical/anesthesia techniques, and delivery methods. Notwithstanding these aspects, no adverse events have thus far been reported and ovarian PRP appears well tolerated by patients. Here, early studies guiding the transition of ‘ovarian rejuvenation’ from experimental to clinical are outlined, with mechanisms to explain results observed in both veterinary and human ovarian PRP research. Current and future challenges for intraovarian cytokine treatment are also discussed.

The Biological Use of Platelet-Rich Plasma in Skeletal Muscle Injury and Repair

Platelet-rich plasma (PRP) is a blood product that contains several growth factors and active proteins. PRP is thought to be used autologously to assist in the repair of injured tissues as well as to treat pain at the site of injury. The mechanism behind PRP in regenerative medicine has been well investigated and includes the identification and concentration of released growth factors and exosomes. The benefits of PRP have been highly recommended and are used widely in orthopaedics and sports medicine, including repair of injured skeletal muscle. This current report summarizes some of the more recent studies in the use of PRP as it relates to muscle healing, in both the in vitro and clinical arenas.

Platelet-rich plasma in hair loss-Mechanism, preparation, and classification

Platelet-rich plasma is the autologous plasma containing platelet concentration more than the baseline separated after centrifugation. It has become a very popular option for the treatment of hair loss in the past few decades. Used alone or in combination with other treatment options it has found a place as a hair restoration procedure throughout the world. However, evidence supporting its credibility is quite ambiguous with contradictory reports available in the literature. In this article, we try to analyze the available data regarding its mechanism of action, preparation protocols, and classification, with regard to hair loss.

Healing of Chronic Wounds with Platelet-Derived Growth Factors from Single Donor Platelet-Rich Plasma following One Freeze-Thaw Cycle. A Cross-Sectional Study

Chronic non-healing wounds (CNHWs) may be associated with trauma or idiopathic in nature and are difficult to treat. Our objective was to assess the use of platelet-derived growth factor (PDGF) from single-donor platelets (al-PRP), using one freeze-thaw cycle, for treating CNHWs. We conducted a cross-sectional study. A total of 23 CNHWs being treated with al-PRP. The al-PRP treatment can be considered successful in well over half (n = 13, 56.5%) of the wounds. We found that all the wounds treated for up to 7 weeks showed partial or complete healing, while those treated for between 8 and 12 weeks did not show healing, healing again being successful in cases in which treatment was extended to more than 13 weeks (85.7%). Using chi-square tests, this relationship was found to be highly significant (p < 0.001, chi² = 19.51; p value = 0.00006). Notably, Cramer's V coefficient was very high (0.921), indicating that the effect size of PRP treatment duration on healing is very large (84.8%). We could suggest that the use of al-PRP in the healing of CNHWs is a promising approach. Further studies with larger sample sizes and long follow-ups are needed to obtain multivariate models to explain which factors favour the healing of ulcers treated with PRP.

Subcision, chemical peels, and platelet-rich plasma: Combination approaches for the treatment of striae distensae

Striae distensae (SD) are disfiguring skin condition causing cosmetic troubles and psychological distress. The aim was to compare the efficacy and safety of platelet-rich plasma (PRP) versus its combination with subcision or medium-depth peeling (glycolic acid 70% followed by trichloroacetic acid [TCA] 35%) for SD treatment. Seventy-five female patients with SD were divided into three equal groups with the contralateral side in each patients represented the control group. Group A treated with PRP, group B received PRP + subcision while group C received PRP + combined peeling (GA 70% + TCA 35%). Primary outcome included clinical improvement, patients' satisfaction, and Dermatology Life Quality Index (DLQI). Striae measurement, skin biopsies were also assessed. Very much improvement was achieved in 28%, 44%, and 36% in groups A, B, and C respectively. The combined groups (B and C) showed significantly higher patients' satisfaction and DLQI than group A (p = 0.03), (p < 0.0001). A significant decrease in all striae measurements was achieved with all groups (p < 0.001); however, groups B and C showed more decrease (p = 0.2 and 0.4). A highly significant decrease in the mean number of sessions was found in group B (p < 0.0001). All groups demonstrated improvement in dermal collagen deposition, which was higher in the combined groups. Side effects were mild and well tolerated. The combination of PRP with subcision or peeling was more effective and offered a higher therapeutic response than PRP alone. Moreover, the subcision has superior efficacy in striae albae and safer in darker skin types.

Effect of Combined Leukocyte-Poor Platelet-Rich Plasma and Hyaluronic Acid on Bone Marrow-Derived Mesenchymal Stem Cell and Chondrocyte Metabolism

OBJECTIVE

Given the potential applications of combined biologics, the authors sought to evaluate the in vitro effect of combined platelet-rich plasma (PRP) and hyaluronic acid (HA) on cellular metabolism.

DESIGN

Bone marrow-derived mesenchymal stem cells (BMSCs) and chondrocytes were obtained from the femurs of Sprague-Dawley rats. An inflammatory model was created by adding 10 ng/mL interleukin-1-beta to culture media. Non-crosslinked high-molecular-weight HA, activated-PRP (aPRP), and unactivated-PRP (uPRP) were tested. Cellular proliferation and gene expression were measured at 1 week. Genes of interest included aggrecan, matrix metalloproteinase (MMP)-9, and MMP-13.

RESULTS

Combined uPRP-HA was associated with a significant increase in chondrocyte and BMSC proliferation at numerous preparations. There was a trend of increased chondrocyte aggrecan expression with combined PRP-HA. The greatest and only significant decrease in BMSC MMP-9 expression was observed with combined PRP-HA. While a significant reduction of BMSC MMP-13 expression was seen with PRP and HA-alone, a greater reduction was observed with PRP-HA. MMP-9 chondrocyte expression was significantly reduced in cells treated with PRP-HA. PRP-alone and HA-alone at identical concentrations did not result in a significant reduction. The greatest reduction of MMP-13 chondrocyte expression was observed in chondrocytes plus combined PRP-HA.

CONCLUSIONS

We demonstrated a statistically significant increase in BMSC and chondrocyte proliferation and decreased expression of catabolic enzymes with combined PRP-HA. These results demonstrate the additive in vitro effect of combined PRP-HA to stimulate cellular growth, restore components of the articular extracellular matrix, and reduce inflammation.

Platelet Rich Plasma Hybridized Adipose Transplant (PHAT) for the Treatment of Hair Loss: A Case Series

Background

Platelet-rich plasma (PRP) has long been used for the restoration of hair in conjunction with microneedling or on its own. Fat grafting to the scalp has also been utilized in the past to improve the quality of hair and the possibility of successful hair transplant. The novel therapy reported in this case series combines the natural progression of these two techniques and utilizes synergistic effects to improve the quality of hair, either in preparation for micrografting or without hair transplant.

Objectives

To demonstrate the principles behind the novel approach to restoration of hair and the rationale for its use.

Methods

A review of the evidence for PRP and fat transfer for non-scarring alopecia serves as the foundation for the combination treatment reported herein. Through presentation of three cases in this series, we provide examples of the utility of this approach for non-scarring alopecia. This report includes a female who suffered non-scarring alopecia following COVID-19 hospitalization and intensive care stay where she lost a large percentage of her hair, in addition to two male patients suffering from androgenic alopecia.

Results

Platelet-rich plasma-hybridized adipose transplant hair was shown in these three cases to improve both the quality and density of hair. It improved the density of hair in all patients and was characterized first by a short period of transient hair loss followed by new hair growth which develops starting at 4 weeks and was readily apparent at 12-week follow-up. Results were maintained at 6-month and 1-year follow-up.

Conclusions

PHAT hair offers a combination of beneficial effects—namely the unique healing properties and growth signaling provided by PRP, along with adipocyte angiogenic and growth signaling, which both work to improve scalp quality. The combination of these effects is better than previously characterized PRP injections alone in the hands of these individual practices. This may be due to synergistic interactions at a cellular level, but additional clinical studies are needed to better understand this novel treatment and the observed effects.

Level of Evidence IV

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

Cell Therapy: Types, Regulation, and Clinical Benefits

Cell therapy practices date back to the 19th century and continue to expand on investigational and investment grounds. Cell therapy includes stem cell- and non-stem cell-based, unicellular and multicellular therapies, with different immunophenotypic profiles, isolation techniques, mechanisms of action, and regulatory levels. Following the steps of their predecessor cell therapies that have become established or commercialized, investigational and premarket approval-exempt cell therapies continue to provide patients with promising therapeutic benefits in different disease areas. In this review article, we delineate the vast types of cell therapy, including stem cell-based and non-stem cell-based cell therapies, and create the first-in-literature compilation of the different "multicellular" therapies used in clinical settings. Besides providing the nuts and bolts of FDA policies regulating their use, we discuss the benefits of cell therapies reported in 3 therapeutic areas-regenerative medicine, immune diseases, and cancer. Finally, we contemplate the recent attention shift toward combined therapy approaches, highlighting the factors that render multicellular therapies a more attractive option than their unicellular counterparts.

Autologous matrix-induced chondrogenesis plus peripheral blood concentrate (AMIC+PBC) in chondral defects of the first metatarsophalangeal joint

OBJECTIVE

Chondral restoration in chondral defects of the 1st metatarsophalangeal joint (MTP1) using autologous matrix-induced chondrogenesis plus peripheral blood concentrate (AMIC+PBC).

INDICATIONS

Chondral defects MTP1.

CONTRAINDICATIONS

Acute infection.

SURGICAL TECHNIQUE

Thigh tourniquet. Medial approach. Tenolysis of all tendons, arthrolysis, synovectomy. Bursectomy in case of bursitis. Resection osteophytes, optional cheilectomy. Debridement of chondral defects until surrounding cartilage stable. Microfracturing with 1.6 mm K‑wire. 15 cc peripheral venous blood harvested with double lumina syringe. Centrifugation (10 min, 1500 RPM). Aspiration of supernatant including the entire fluid layer directly above the erythrocyte layer (peripheral blood concentrate [PBC]). Chondro-Gide matrix was cut to size and impregnated in PBC 3 min (impregnation). Fixation of the matrix into the chondral defect with fibrin glue (AMIC+PBC). Joint motion to ensure stable fixation. Insertion drainage and wound infiltration catheter. Layer wise closure.

POSTOPERATIVE MANAGEMENT

Full weightbearing in a dressing shoe. Joint motion exercise starting at the day of surgery.

RESULTS

The aim of the study was to compare matrix-associated stem cell transplantation (MAST) with AMIC+PBC. Patients who were treated with MAST from October 1, 2011 to July 15, 2016 (n = 623) or with AMIC+PBC from July 17, 2016 to March 19, 2018 (n = 230) were included. In all, 480 (89%)/176 (89%) patients (MAST/AMIC+PBC) completed 2‑year follow-up. The average degree of osteoarthritis was 2.1/2.2. The chondral defect size was 0.9/1.0 cm² on average. Visual Analogue Scale Foot and Ankle (VAS FA) and European Foot and Ankle Society score (EFAS score) improved to 72.4/74.1//16.8/17.1 (MAST//AMIC+PBC) at follow-up, respectively. No parameter significantly differed between the MAST and AMIC+PBC cohorts.

Comparing the efficacy of dual Platelet-Rich Plasma (PRP) and Hyaluronic Acid (HA) therapy with PRP-alone therapy in the treatment of knee osteoarthritis: a systematic review and meta-analysis

Purpose

This study aims to compare the efficacy of a dual therapy of Platelet-Rich Plasma (PRP) and Hyaluronic Acid (HA) compared with PRP-alone therapy in the treatment of knee osteoarthritis (KOA).

Methods

PubMed, Embase, CINAHL, SCOPUS, Cochrane Library, grey literature and bibliographic references were searched from inception to January 2021. Only randomized controlled trials (RCTs) and retrospective cohort studies comparing the effect of PRP and HA versus PRP-alone therapy for KOA were included. Literature retrieval and data extraction were conducted by three independent reviewers. Pooled analysis of Visual Analogue Scale (VAS), Western Ontario and McMaster Universities Arthritis Index (WOMAC), International Knee Documentation Committee (IKDC) scores and adverse events were conducted.

Results

Ten studies (7 RCTs, 3 cohort studies) involving 983 patients were covered. Dual PRP and HA therapy resulted in significant reduction in VAS compared to PRP-alone therapy at 4–6 weeks (P < 0.00001) and 12 months (P < 0.00001). Dual therapy resulted in better WOMAC score improvement at 3 (P = 0.02), 6 (P = 0.05) and 12 months (P < 0.0001) compared to PRP-alone therapy. The IKDC score for dual therapy was also higher at 6 months compared to PRP-alone therapy (P = 0.007). Regarding adverse events, dual therapy was generally safer than PRP-alone therapy (P = 0.02).

Conclusion

While there is a paucity of large high-quality Level I studies, current best evidence suggests that dual therapy with PRP and HA for KOA may be effective at providing pain relief and improvement in function up to 1 year following administration.

Level of evidence

II.

Hypertonic Dextrose Prolotherapy, an alternative to intra-articular injections with Hyaluronic Acid in the treatment of knee osteoarthritis: systematic review and meta-analysis

ABSTRACT

Intra-articular injections with hyaluronic acid are recommended in the treatment of knee osteoarthritis (KOA); however, hypertonic dextrose prolotherapy (HDP) has been reported as effective and safe. The aim was to evaluate the effectiveness of HDP for pain reduction and improvement of function in individuals with KOA in comparison with hyaluronic acid by meta - analysis. The search was performed in electronic databases. Six studies were included (395 participants). No statistically significant differences were found between prolotherapy and hyaluronic acid in pain control in the short term, however, in the sub-analysis where included only the studies that used intra-articular injection within the prolotherapy scheme, an effect was found in favor of the prolotherapy groups (d = -1.33, 95% CI -2.50 to -0.16, p (z) 0.03). Also, an effect was found in favor of the prolotherapy group in the improvement in function (d = -1.05, 95% CI -2.03 to -0.08, p (z) 0.03). No major adverse reactions or side effects were reported in any of the studies. HDP appears to be an effective intervention to decrease pain and improve function in KOA, with efficacy similar to intra-articular injections with hyaluronic acid in the short-term follow-up. Nonetheless, better-quality clinical trials are necessary.

Platelet-Rich Plasma: A Comprehensive Review of Emerging Applications in Medical and Aesthetic Dermatology

Platelet-rich plasma (PRP) has been integrated into numerous treatment regimens for medical and aesthetic dermatology. While some of these approaches are well-established, many uses are underreported in the literature. We sought to identify and summarize the emerging dermatologic applications for PRP by conducting a comprehensive PubMed search of studies published between 2000 and 2020. These studies were reviewed to synthesize collection methods, treatment schedule, adverse effects, and the impact of therapy for new and emerging uses for PRP. In general, we identified positive treatment outcomes for skin rejuvenation, scar revision, alopecia, pigmentary disorders, lichen sclerosus, leprosy-induced peripheral neuropathy, plaque psoriasis, and nail disorders. Widely, therapy was well-tolerated and suitable for all reported phototypes. The variations in collection and application sequences make concrete recommendations difficult to discern, underscoring the need for a standardized approach to preparation and treatment methods. We hope this review serves as an outline for new and interesting uses for PRP and will help readers familiarize themselves with this exciting technology for comfortable integration into their practices.

OPTIMIZING A PLATELET-RICH PLASMA CONCENTRATION PROTOCOL FOR SOUTH AMERICAN SEA LIONS (OTARIA FLAVESCENS)

Accelerated healing in wild or captive South American sea lions (Otaria flavescens) is a key tool to help minimize infection and complications associated with open wounds, dental disease, and ocular pathology. Platelet-rich plasma (PRP) is an autogenous source for growth factors based on platelet concentration, which can be obtained by centrifuging whole blood collected in sodium citrate anticoagulant. Currently, there are well-defined PRP concentration protocols for humans and most domestic companion animal species. However, there is no clear centrifugation protocol for obtaining PRP in most marine mammal species. This study aimed to optimize the platelet concentration protocol based on whole blood centrifugation using speeds ranging from 500 to 5,000 rpm and times ranging from 3 to 6 min. Blood was drawn from seven adult South American sea lions, placed into 1-ml sodium citrate tubes, and centrifuged following 12 different centrifugation protocols. PRP was designated as the lower third fraction of the centrifuged plasma. Platelet counts were performed using flow cytometry and statistical analysis was carried out to establish a well-defined protocol for efficient PRP production. Transmission electron microscopy (TEM) analysis was performed to evaluate possible platelet degranulation during the different centrifugation protocols and measure platelet areas. Maximum concentration of platelets in PRP was 4.73-fold higher than the number of platelets in equal volume of whole blood, and significant differences in the concentrations obtained were found between the 12 centrifugation protocols evaluated using different speed and time combinations. The best one-step centrifugation protocol resulted from using 900-rpm speed for 3 min. The highest-fold increase was achieved using a two-step centrifugation protocol, which combined the most efficient one-step centrifugation protocol (900 rpm, 3 min) with a second centrifugation using 2,000-rpm speed for 6 min. TEM analysis confirmed that platelets were complete and maintained integrity after the proposed protocol.

Regeneration of dentin-pulp complex by using dental pulp stem cells in dog

INTRODUCTION

Although missing tooth is not life-threatening, it affects the quality of daily life. Stem cells have emerged as an important player in the generation and maintenance of many tissues. The role of scaffolds has changed from a passive carrier to a bioactive matrix, which can be used to induce cellular behavior. The aim of this study was to determine the possibility of regeneration of dentin-pulp complex with dental pulp stem cells (DPSCs) in an animal model.

MATERIALS AND METHODS

In this animal study after extraction of DPSCs and cultivation, 10 types of scaffolds were made by using platelet-rich plasma (PRP), cancellous bone, and collagen pad. They were inserted in different parts of the dog's mouth. After the 4^th month, the area was operated, and the scaffolds were removed.

RESULTS

Microscopic examination revealed no sign of cell differentiation and formation of new structures in those models which used collagen scaffolds. However, the dentin-pulp complex emerged in models that the combination of bone scaffolds and PRP or stem cells was used.

CONCLUSION

Using bone scaffolds in combination with PRP or DPSCs to regenerate dentin-pulp complex in dog helped odontoblastic and pulpal differentiation as well as the formation of predentin and tubular dentin.

Red blood cells and their releasates compromise bone marrow-derived human mesenchymal stem/stromal cell survival in vitro

PURPOSE

The use of bone marrow aspirate (BMA) and bone marrow aspirate concentrate (BMC) in the treatment of inflammatory orthopedic conditions has become a common practice. The therapeutic effect of BMA/BMC is thought to revolve primarily around the mesenchymal stem/stromal cell (MSC) population residing within the nucleated cell fraction. MSCs have the unique ability to respond to site of injury via the secretion of immunomodulating factors, resolving inflammation in diseased joints. Recently, the importance of hematocrit (HCT) in BMC has been debated, as the potential impact on MSC function is unknown. In the present study, we investigate MSC health over a short time-course following exposure to a range of HCT and red blood cell releasate (RBC_rel) conditions.

METHODS

Bone marrow-derived human MSCs in early passage were grown under conditions of 0%, 2.5%, 5%, 10%, 20% and 40% HCT and RBC_rel conditions for 3 days. At each day, the percentage of viable, apoptotic and necrotic MSCs was determined via flow cytometry. Relative viable MSC counts in each condition was determined to account for dynamic changes in overall MSC densities over the time-course. Statistical analysis was performed using a one-way ANOVA comparing test conditions to the control followed by a Dunnett's multiple comparison test.

RESULTS

Significant reductions in viable MSCs concurrent with an increase in necrotic MSCs in high HCT and RBC_rel conditions was observed within 24 h. At each successive timepoint, the percent and relative number of viable MSCs were reduced, becoming significant in multiple HCT and RBC_rel conditions by Day 3. Necrosis appears to be the initial mode of MSC death following exposure to HCT and RBC_rel, followed by apoptosis in surviving MSC fractions.

CONCLUSION

Various levels of HCT and RBC_rel severely compromise MSC health within 3 days and HCT should be controlled in the preparation of BMC products. Further, HCT of BMCs should be routinely recorded and tracked with patient outcomes along with routine metrics (e.g. nucleated cell counts, fibroblast-colony forming units). Differences in HCT may account for the inconsistencies in the efficacy of BMC reported when treating orthopedic conditions.

Mechanical Properties of Human Concentrated Growth Factor (CGF) Membrane and the CGF Graft with Bone Morphogenetic Protein-2 (BMP-2) onto Periosteum of the Skull of Nude Mice

Concentrated growth factor (CGF) is 100% blood-derived, cross-linked fibrin glue with platelets and growth factors. Human CGF clot is transformed into membrane by a compression device, which has been widely used clinically. However, the mechanical properties of the CGF membranes have not been well characterized. The aims of this study were to measure the tensile strength of human CGF membrane and observe its behavior as a scaffold of BMP-2 in ectopic site over the skull. The tensile test of the full length was performed at the speed of 2mm/min. The CGF membrane (5 × 5 × 2 mm3) or the CGF/BMP-2 (1.0 μg) membrane was grafted onto the skull periosteum of nude mice (5-week-old, male), and harvested at 14 days after the graft. The appearance and size of the CGF membranes were almost same for 7 days by soaking at 4 °C in saline. The average values of the tensile strength at 0 day and 7 days were 0.24 MPa and 0.26 MPa, respectively. No significant differences of both the tensile strength and the elastic modulus were found among 0, 1, 3, and 7 days. Supra-periosteal bone induction was found at 14 days in the CGF/BMP-2, while the CGF alone did not induce bone. These results demonstrated that human CGF membrane could become a short-term, sticky fibrin scaffold for BMP-2, and might be preserved as auto-membranes for wound protection after the surgery.

Prophylactic use of platelet-rich plasma for post-spinal low back pain following gynecological surgery: a randomized clinical trial

BACKGROUND

Post-spinal back pain is suggested to occur as a result of a localized inflammatory response that is often associated with some degree of muscle spasm. We aimed to evaluate the effect of platelet-rich plasma (PRP) in reducing the incidence of post-spinal back pain.

METHODS

One hundred patients were randomly enrolled and scheduled for elective gynecological surgery under spinal anesthesia. After the subarachnoid block, group A (placebo) received 2 mL of sodium chloride 0.9% injected into the track of spinal needle during its withdrawal (2 mm after outward withdrawal in muscles and subcutaneous tissues). While patients in group B (PRP); received 2 ml of PRP injected into the track of the spinal needle during its withdrawal. The primary outcome was the number of patients who developed post-spinal low back pain within the first week following the subarachnoid block. Secondary outcomes included the time of the first analgesic request and total meperidine consumption during the first 24 h postoperatively.

RESULTS

Fifteen patients in the PRP group developed low back pain during the first week following subarachnoid block compared to 26 patients in the placebo group (p = 0.037). There was a significant decrease in the mean meperidine consumption during first 24 h postoperatively in PRP group (174 ± 14 mg) compared to placebo group (210 ± 22 mg) (p < 0.0001). Also, the first analgesic request was significantly delayed in PRP group (243 ± 21 min.) compared to placebo group (185 ± 31 min.) (p < 0.0001).

CONCLUSION

This study demonstrated the positive effects of platelet-rich plasma on the prevention of post-spinal backache.

Evaluation of the Effects of Platelet-Rich Plasma on Follicular and Endometrial Growth: A Literature Review

Platelet-rich plasma (PRP) has been used in several areas of medicine due to its ability to promote tissue regeneration by growth factors and cytokines. This review addresses the use of PRP to rejuvenate ovarian follicles and increase the thickness of the endometrium to receive an embryo. PRP is obtained from the patient's own blood (autologous blood) - a fact that determines a lower chance of rejection reactions. Alpha granules of platelets provide and release supra physiological amounts of growth factors and cytokines, which provide a regenerative stimulus in tissues with low healing potential. In the ovary, PRP and its growth factors stimulate vascularization and recruitment of available primordial follicles that could no longer be otherwise stimulated. The rejuvenation of the ovary by PRP infusion aims to obtain new oocytes in ovaries with low numbers of follicles or low follicular reserve markers. In the preparation of the endometrium, PRP is used for its several growth factors that allow tissue proliferation and endometrial thickening, especially in cases of endometria that are difficult to prepare or that fail to reach an adequate minimum thickness (>7mm). To date, there are few studies of greater expression in the literature that support the use of PRP with the two purposes described above. Thus, although promising, the technique must still be validated by larger clinical trials.