Apheresis Platelet Rich-Plasma for Regenerative Medicine: An In Vitro Study on Osteogenic Potential

Biologic therapies in stress fractures: Current concepts

Stress fractures, a common overuse injury in physically active individuals, present a significant challenge for athletes and military personnel. Patients who sustain stress fractures have demanding training regimes where periods of rest and immobilisation have unacceptable negative consequences on sports goals and finances. Aside from being an overuse injury, there are various contributing risk factors that put certain individuals at risk of a stress fracture. The main two being nutritional deficiencies and hormonal variations, which have significant effects on bone metabolism and turnover. Historically, treatment of stress fractures focused on conservative strategies such as rest and immobilisation. Calcium and vitamin D deficiencies have been closely linked to stress fractures and so over time supplementation has also played a role in treatment. With the introduction of biologics into orthopaedics, newer treatment strategies have been applied to accelerate fracture healing and perhaps improve fracture callus quality. If such therapies can reduce time spent away from sport and activity, it would be ideal for treating stress fractures. This article aims to offer insights into the evolving landscape of stress fracture management. It investigates the pre-clinical evidence and available published clinical applications. Though fracture healing is well understood, the role of biologics for fracture healing is still indeterminate. Available literature for the use of biologic therapies in stress fractures are restricted and most reports have used biologics as a supplement to surgical fixation in subjects in studies that lack control groups. Randomised control trials have been proposed and registered by a few groups, with results awaited. Assessing individuals for risk factors, addressing hormonal imbalances and nutritional deficiencies seems like an effective approach to addressing the burden of stress fractures. We await better designed trials and studies to accurately determine the clinical benefit of adding biologics to the management of these injuries.

Cryopreservation affects platelet macromolecular composition over time after thawing and differently impacts on cancer cells behavior in vitro

Cryopreservation affects platelets' function, questioning their use for cancer patients. We aimed to investigate the biochemical events that occur over time after thawing to optimize transfusion timing and evaluate the effect of platelet supernatants on tumor cell behavior in vitro. We compared fresh (Fresh-PLT) with Cryopreserved platelets (Cryo-PLT) at 1 h, 3 h and 6 h after thawing. MCF-7 and HL-60 cells were cultured with Fresh- or 1 h Cryo-PLT supernatants to investigate cell proliferation, migration, and PLT-cell adhesion. We noticed a significant impairment of hemostatic activity accompanied by a post-thaw decrease of CD42b+ , which identifies the CD62P--population. FTIR spectroscopy revealed a decrease in the total protein content together with changes in their conformational structure, which identified two sub-groups: 1) Fresh and 1 h Cryo-PLT; 2) 3 h and 6 h cryo-PLT. Extracellular vesicle shedding and phosphatidylserine externalization (PS) increased after thawing. Cryo-PLT supernatants inhibited cell proliferation, impaired MCF-7 cell migration, and reduced ability to adhere to tumor cells. Within the first 3 hours after thawing, irreversible alterations of biomolecular structure occur in Cryo-PLT. Nevertheless, Cryo-PLT should be considered safe for the transfusion of cancer patients because of their insufficient capability to promote cancer cell proliferation, adhesion, or migration.

Efficacy and safety of platelet-rich plasma and autologous-serum eye drops for dry eye in primary Sjögren's syndrome: a randomized trial

We compared the efficacy and safety of autologous-serum (AS) and platelet-rich plasma (PRP) eye drops for dry eye (DE) treatment in primary Sjögren's syndrome (SS). This prospective, randomized, double-blinded clinical study included patients diagnosed with primary SS DE. Thirty-eight participants were randomly assigned to the AS or PRP groups. Corneal and conjunctival staining scores, Schirmer I test, tear film break-up time (TBUT), and ocular surface disease index (OSDI) scores were evaluated at 4 and 12 weeks. Conjunctival impression cytology (CIC) metaplasia grade and goblet cell density grade at 12 weeks were compared with those at baseline. Corneal and conjunctival staining scores and TBUT significantly improved at 4 and 12 weeks in both groups (all p < 0.005). No significant difference between the AS and PRP groups was observed at 4 and 12 weeks. The Schirmer I values, OSDI scores, CIC metaplasia grade, and goblet cell density grade did not significantly change at 4 and 12 weeks in either group. Both AS and PRP eye drops are effective for primary SS DE without a significant difference. Considering that the preparation time of PRP is shorter than that of AS, PRP can be a good alternative treatment for primary SS DE.

Method Based on Ultrafiltration to Obtain a Plasma Rich in Platelet and Plasma Growth Factors

Platelet-Rich Plasma (PRP) is an autologous biological product which, due to its regenerative capacity, is currently used in different fields of medicine. This biological treatment has proven to be effective in numerous research studies due to its high content of growth factors released by platelets. However, the current systems used to obtain PRP do not enrich the growth factors and cytokines outside platelets. Considering this, the present work aims to develop a new technique by which all the biomolecules present in plasma are enriched. Thus, a new method based on ultrafiltration has been developed for the obtaining of the novel PRP. By this method, ultrafiltration of the plasma water is carried out using a 3KDa filtering unit. The results showed that the technique was able to concentrate extraplatelet factors, such as IGF-1 and HGF, in contrast with conventional plasmas. Thus, the cultured cells responded with increased viability to this new PRP. These results could provide a new approach to the treatment of injuries requiring regenerative medicine, potentially improving the outcomes of the conventional PRPs.

Homologous platelet gel on radiation-induced dermatitis in a patient receiving head and neck radiotherapy plus cetuximab: A case report

INTRODUCTION

Acute radiodermatitis is a significant complication of cancer radiotherapy, and platelet-based therapies are emerging as potential new treatments.

MAIN SYMPTOMS AND IMPORTANT CLINICAL FINDINGS

In this report, we present the case of a patient with head and neck cancer undergoing radiotherapy combined with the monoclonal antibody cetuximab. After 4 weeks of this treatment, the patient developed cutaneous radiation dermatitis. Despite receiving standard treatment with corticosteroids and emollient cream, the lesion did not improve.

MAIN DIAGNOSIS

cutaneous radiation dermatitis on head and neck cancer patient.

THERAPEUTIC INTERVENTIONS

Topical application of platelet gel was initiated on the wound. From the second week of radiotherapy to the 4th week, homologous platelet-rich plasma was applied on the dermatitis using a bandage, 4 times a day.

OUTCOMES

The topical treatment with homologous platelet gel resulted in complete healing of the radiodermatitis, including restoration of the epidermis, reepithelialization, and reduction in associated pain.

CONCLUSION

homologous platelet gel might be an alternative to standard treatment of radiation dermatitis.

Effect of Autologous Platelet-Rich Plasma Drops in the Treatment of Ocular Surface Disease

Purpose

Platelet rich plasma (PRP) is an autologous preparation that concentrates platelets in a small volume of plasma. The purpose of this study was to determine if PRP eye drops improved the symptoms and signs of ocular surface disease.

Patients and Methods

A retrospective case series was conducted of patients who were prescribed PRP eye drops. Subjects were excluded if they did not have follow-up, underwent intraocular surgery prior to follow-up, received nerve growth factor treatments, or did not have a baseline examination with photography. Symptoms were assessed using the Ocular Surface Disease Index (OSDI). Patients also underwent a slit lamp exam, ocular surface staining with fluorescein and lissamine green, and Schirmer testing.

Results

The charts of 47 patients treated with PRP drops for ocular surface disease were reviewed. Sixty-four eyes of 32 patients were included in the study who had photographs of lissamine green staining taken at baseline and at follow-up. Thirteen patients (28%) had ocular graft-versus-host disease, 16 patients (34%) had Sjögren's syndrome, and 4 patients (8.5%) had rheumatoid arthritis. There was a statistically significant decrease in OSDI score from baseline to follow-up (39.5 vs 30.8 points, p = 0.02). Among the 64 eyes included, 9 (14%) had an improvement in conjunctival lissamine green staining, while 6 (9%) had an increase in staining at follow-up. Among the 20 eyes with Schirmer testing, there was a borderline significant increase in score from baseline to follow-up (5.9 vs 9.7, p = 0.06). Among the 44 eyes that had corneal fluorescein staining (CFS) reported, 8 (18.2%) had decreased staining and 2 (4.5%) had increased staining at follow-up.

Conclusion

Treatment with PRP drops was associated with a significant improvement in symptoms in patients with ocular surface disease. Future larger prospective studies are needed to further evaluate the efficacy of PRP drops for treating ocular surface disease.

Variability in Platelet-Rich Plasma Preparations Used in Regenerative Medicine: A Comparative Analysis

Background

Platelet-rich plasma (PRP) and its derivatives are used in several aesthetic, dental, and musculoskeletal procedures. Their efficacy is primarily due to the release of various growth factors (GF), interleukins, cytokines, and white blood cells. However, the PRP preparation methods are highly variable, and studies lack consistency in reporting complete procedures to prepare PRP and characterize PRP and its derivatives. Also, all the tissue-specific (in vivo and in vitro) interactions and functional properties of the various derivatives/factors of the PRP have not been taken into consideration by any study so far. This creates a potential space for further standardization of the PRP preparation methods and customization of PRP/PRP derivatives targeted at tissue-specific/pathology specific requirements that would enable efficacious and widely acceptable usage of PRP as main therapy, rather than being used as adjuvant therapy. The main objective of our study was to investigate the variability in PRP preparation methods and to analyze their efficacy and reliability.

Method

This study considered articles published in the last 5 years, highlighting the variability in their PRP preparation methods and characterization of PRP. Following the PRISMA protocol, we selected 13 articles for the study. The selected articles were assessed using NHLBI quality assessment tool.

Results

We noted differences in (1) approaches to producing PRP, (2) extent of characterization of PRP, (3) small scale and large-scale preparation methods, (4) in vitro and in vivo studies.

Conclusion

We identified two studies describing the procedures which are simple, reproducible, economical, provide a good yield of platelets, and therefore can be considered methods for further tissue-specific and pathology-specific standardizations of PRP and its derivatives. We recommend further randomized studies to understand the full therapeutic potential of the constituents of PRP and its derivatives.

Platelet-rich plasma promotes diabetic ulcer repair through inhibition of ferroptosis

BACKGROUND

Ferroptosis, a newly discovered form of cell death, can accumulation activates lipid peroxidation and excessive oxidative stress in a high glucose environment. These phenomena suggest there may be ferroptosis pathways in the pathological processes associated with diabetic ulcer (DU). Platelet-rich plasma (PRP) promotes the healing of DU wounds, which may be achieved by the regulation of ferroptosis pathways. Hence, the present study aimed to investigate this association and uncover the potential underlying mechanisms.

METHODS

Cell injury models induced by high glucose were constructed using EA.HY926 (vascular endothelial cells), HSF (fibroblasts), and rat DU models. The MDA, total ROS, total SOD content, the gene and protein expression of GPX4, SLC7A11, and ACSL4, and the expression levels of inflammatory cytokines IL-1β, IL-10, and NLRP3 was subsequently used to evaluate the important role of ferroptosis in the pathological process of DU, and elucidating the molecular mechanism of PRP in ulcer repair.

RESULTS

The results show that compared with the DU control group, the healing rate of the dorsal ulcer wound in the PRP intervention group was accelerated, and the expression levels of inflammatory cytokines IL-1β, IL-10, and NLRP3 in the granulation tissue of ulcer wounds was lower. Further, the expression levels of CD31 and VEGF were higher, the gene and protein expression levels of GPX4 and SLC7A11 were increased, the expression levels of ACSL4 were less, the SOD content was higher, and the MDA content was lower.

CONCLUSIONS

In this study, ferroptosis was preliminarily verified in DUs at the cellular and animal levels, while PRP could inhibit ferroptosis and significantly improve the migration and regeneration ability of fibroblasts and vascular endothelial cells induced by high glucose.

Ultrasound-guided platelet-rich-plasma injections for reducing sacroiliac joint pain: A paradigmatic case report and literature review

BACKGROUND

Sacro-iliac joint (SIJ) pain is an often-misdiagnosed cause (up to 30% cases) of atypical low back pain (LBP) that might be treated with a wide range of conservative interventions. However, Platelet-Rich-Plasma (PRP) ultrasound-guided injections at SIJ level in subjects with mitochondrial disorders have not yet been investigated.

CASE PRESENTATION

A 52-year-old Caucasian male with fluoroquinolone-related mitochondrial dysfunction referred to a Physical Medicine and Rehabilitation Outpatient, complaining of severe SIJ pain (Numeric Pain Related Scale, NPRS=8). We performed two bilateral PRP ultrasound-guided injections at the sacro-iliac level. PRP is a simple, efficient, and minimally invasive approach. After the first PRP injection, there was a considerable reduction of pain (NPRS=8 vs 5). The second PRP infiltration was performed after 2 weeks and in both cases no adverse events. At the 6-month follow-up evaluation, the patient showed good physical recovery, with the absence of pain (NPRS=0).

CONCLUSION

To the best of our knowledge, this is the first report in the literature assessing the safety and effectiveness of PRP ultrasound-guided injections for SIJ pain in a patient affected by mitochondrial disorders. Thus, this case report might have relevant clinical implications in the treatment of SIJ pain in patients affected by this rare pathological condition, albeit further observational studies are warranted to confirm these findings.

Differential Protein Content between Fresh and Freeze-Dried Plasma Rich in Growth Factors Eye Drops

The purpose of this study was to analyze the proteomic composition of plasma rich in growth factors eye drops (PRGF) in comparison to lyophilized PRGF eye drops (PRGF lyo). The differential protein expression of keratocyte (HK) cells after PRGF or PRGF lyo treatment was also determined. Blood from different donors was collected and processed to obtain PRGF and PRGF lyo eye drops. Then, HK cells were treated with both formulations. A proteomic analysis was performed to evaluate the differential proteomic profile between PRGF and PRGF lyo, and the differential protein expression by HK cells after treatment with both blood-derived products. About 280 proteins were detected between both blood-derived formulation, with only 8 of them reaching significant differences. Furthermore, 101 out of 3213 proteins showed statistically significant deregulation in HK cells after treatment with PRGF or PRGF lyo. Gene Ontology analysis showed that these significant deregulated proteins were involved in 30 functional processes. However, the Ingenuity Pathway Analysis showed that no significant differences were found in any of the identified processes. In summary, the present study show that no significant differences were found in the proteomic profile or in the signaling pathways activation in HK cells between PRGF and PRGF lyo.