Small Volumes Of Plasma Research Articles

Chemical Exposomics in Human Plasma by Lipid Removal and Large-Volume Injection Gas Chromatography-High-Resolution Mass Spectrometry.

For comprehensive chemical exposomics in blood, analytical workflows are evolving through advances in sample preparation and instrumental methods. We hypothesized that gas chromatography-high-resolution mass spectrometry (GC-HRMS) workflows could be enhanced by minimizing lipid coextractives, thereby enabling larger injection volumes and lower matrix interference for improved target sensitivity and nontarget molecular discovery. A simple protocol was developed for small plasma volumes (100-200 μL) by using isohexane (H) to extract supernatants of acetonitrile-plasma (A-P). The HA-P method was quantitative for a wide range of hydrophobic multiclass target analytes (i.e., log Kow > 3.0), and the extracts were free of major lipids, thereby enabling robust large-volume injections (LVIs; 25 μL) in long sequences (60-70 h, 70-80 injections) to a GC-Orbitrap HRMS. Without lipid removal, LVI was counterproductive because method sensitivity suffered from the abundant matrix signal, resulting in low ion injection times to the Orbitrap. The median method quantification limit was 0.09 ng/mL (range 0.005-4.83 ng/mL), and good accuracy was shown for a certified reference serum. Applying the method to plasma from a Swedish cohort (n = 32; 100 μL), 51 of 103 target analytes were detected. Simultaneous nontarget analysis resulted in 112 structural annotations (12.8% annotation rate), and Level 1 identification was achieved for 7 of 8 substances in follow-up confirmations. The HA-P method is potentially scalable for application in cohort studies and is also compatible with many liquid-chromatography-based exposomics workflows.

Pharmacokinetic profiles of methylcobalamin in rats after multiple administration routes by a simple LC-MS/MS assay with a small volume of plasma

Methylcobalamin (MBL) is a vitamin B12 coenzyme and is effective for treating peripheral neuropathies. Little is known about pharmacokinetics (PK) of MBL in animals, we have developed a simple assay for MBL by using only 0.01 mL of plasma for PK of MBL in rats. Under minimal light exposure (<5 lx), MBL was extracted by a simple protein precipitation using methanol and detected by liquid chromatography with tandem mass spectrometry. MBL in rat plasma at 20–10,000 ng/mL was quantified using only 0.01 mL of plasma. Relative error and relative standard deviation met the acceptance criteria in reproducibility assessments, indicating the robustness of the assay. PK of MBL was evaluated after intravenous, intramuscular, and subcutaneous administration. PK of MBL was dose proportional at 5–20 mg/kg in both intramuscular and subcutaneous administrations. Bioavailability after the two dosing routes was complete (ca. 100 %). The incurred sample reanalysis also supported that the assay is robust. The established assay was successfully applied to PK studies in rats to find that MBL showed high bioavailability after intramuscular and subcutaneous administrations.

Platelet-rich plasma in dermatology and aesthetic medicine

Introduction and purpose Aesthetic medicine is one of the youngest fields of medicine. Initially, it focused on improving the quality of life of patients by using various treatments aimed at stopping the aging process. Over time, this branch of medicine has developed dynamically, and nowadays the treatments focus not only on improving the appearance of the skin and its defects, but are also used to treat many dermatological problems. Platelet-rich plasma (PRP) is an autologous concentrate of platelets in a small volume of plasma. having numerous applications in many fields of medicine. The aim of this work is to present the method, focusing on its positive effects in the problems of aesthetic and regenerative medicine, as well as in some dermatological diseases. Material and methods The review was baised on the articles obtained from Pubmed and Google Scholar scientific databases from recent years using the keywords: aesthetic medicine, platelet-rich plasma, dermatology. Results The presence of numerous growth factors and other active ingredients makes the action of PRP comprehensive and based on several mechanisms. Studies show a positive effect, especially in skin rejuvenation and anti-aging prevention, hair reconstruction, wound healing and reconstruction of scars of various etiologies, as well as in pigmentation disorders. Moreover, combining PRP with other methods such as laser therapy or microneedling produces a synergistic effect, improving overall treatment results. Conclusions Platelet-rich plasma is an autologous preparation obtained after centrifugation of blood collected from the patient. The properties of PRP make it widely used in many clinical situations. is used both in aesthetic medicine and in dermatological problems. It should be emphasized that further multi-center studies are needed to standardize treatment protocols and adapt them to specific problems. Keywords: aesthetic medicine, platelet-rich plasma, dermatology.

Capillary Force-Driven Quantitative Plasma Separation Method for Application of Whole Blood Detection Microfluidic Chip.

Separating plasma or serum from blood is essential for precise testing. However, extracting precise plasma quantities outside the laboratory poses challenges. A recent study has introduced a capillary force-driven membrane filtration technique to accurately separate small plasma volumes. This method efficiently isolates 100-200 μL of pure human whole blood with a 48% hematocrit, resulting in 5-30 μL of plasma with less than a 10% margin of error. The entire process is completed within 20 min, offering a simple and cost-effective approach to blood separation. This study has successfully addressed the bottleneck in self-service POCT, ensuring testing accuracy. This innovative method shows promise for clinical diagnostics and point-of-care testing.

Pesticides in small volume plasma samples: Method development and application to smallmouth bass (Micropterus dolomieu) from the Chesapeake Bay watershed, USA

Nontarget organisms are exposed to pesticides following applications in agricultural and urban settings, potentially resulting in deleterious effects. Direct measurements of pesticides in biological tissues may aid in characterizing exposure, accumulation, and potential toxicity versus analyses in environmental media alone (e.g., water, soil, and air). Plasma represents a nonlethal sampling medium that can be used to assess recent exposures to contaminants. Herein, a method was developed to test the extraction of 210 pesticides and their transformation products in small volume plasma samples (100 μL). Plasma samples were protein precipitated with 0.5 % formic acid in acetonitrile added to the sample (ratio of 3.5:1). Pass-through solid phase extraction was used for sample matrix and lipid removal and samples were analyzed by liquid chromatography and gas chromatography with tandem mass spectrometry. Recoveries of 70.0–129.8 % were achieved for 182 pesticides and degradates across the low (25 ng mL−1), medium (100 ng mL−1), and high (250 ng mL−1) spike levels. Method detection levels ranged 0.4–13.0 ng mL−1. Following development, the method was applied to smallmouth bass (Micropterus dolomieu) plasma samples (n = 10) collected from adults in the Chesapeake Bay watershed. Individual plasma samples resulted in four to seven analytes detected with summed concentrations ranging 16.4–95.0 ng mL−1. Biological multiresidue pesticide methods help elucidate recent exposures of bioactive compounds to nontarget organisms.

Platelet-rich plasma - a revolutionary therapeutic option in multi-disciplinary indications

Background: Platelet-rich plasma (PRP) was originally described as a small volume of plasma that contains higher concentrations of platelets, compared to peripheral blood. Although currently the use of PRP in most indications is off-label, it is not prohibited. Initially, PRP was used for wound healing and tissue regeneration in fields such as orthopaedics, dermatology, maxillofacial surgery and dentistry.&#x0D; Aim of the study: The aim of this article was to present and summarise the modern production methods, the mechanism of action at the molecular and biochemical level and the most important uses and indications of PRP in present-day medicine.&#x0D; Material and methods: A cross-sectional search of relevant literature was performed in databases using accepted wording. Publications from 2003-2023 were included. The entire process has been supplemented with additional procedures to increase the reliability of this publication.&#x0D; Results: Orthopaedics has gained many minimally invasive therapeutic solutions thanks to PRP. Its effects on ligament and tendon tissues have been studied, where promising data have been proven. Also in aesthetic medicine and dermatology, many treatment strategies have been developed using PRP, mainly for the treatment of acne, androgenic alopecia and delaying tissue ageing as much as possible.&#x0D; Conclusion: Platelet-rich plasma has found application in the treatment of many conditions in orthopaedics, dermatology, aesthetic medicine and dentistry. It is characterised by good therapeutic efficacy, with relatively low risk. However, high-quality studies are still lacking to provide more reliable data.

Multichannel resonant acoustic rheometry system for quantification of coagulation of multiple human plasma samples

Resonant Acoustic Rheometry (RAR), a newly developed ultrasound-based technique for non-contact characterization of soft viscoelastic materials, has shown promise for quantitative viscoelastic assessment of temporally changing soft biomaterials in real time, and may be used to monitor blood coagulation process. Here, we report the development of a novel, multichannel RAR (mRAR) system for simultaneous measurements of multiple temporally evolving samples and demonstration of its use for monitoring the coagulation of multiple small-volume plasma samples. The mRAR system was constructed using an array of 4 custom-designed ultrasound transducers at 5.0 MHz and a novel electronic driving system that controlled the generation of synchronized ultrasound pulses for real time assessment of multiple samples simultaneously. As a proof-of-concept of the operation of the mRAR system, we performed tests using pooled normal human plasma samples and anti-coagulated plasma samples from patients treated with warfarin with a range of International Normalized Ratio (INR) values as well-characterized samples with different coagulation kinetics. Our results show that simultaneous tracking of dynamic changes in 4 plasma samples triggered by either kaolin or tissue factor was achieved for the entire duration of coagulation. The mRAR system captured distinct changes in the samples and identified parameters including the clotting start time and parameters associated with the stiffness of the final clots that were consistent with INR levels. Data from this study demonstrate the feasibility of the mRAR system for efficient characterization of the kinetic coagulation processes of multiple plasma samples.

A Simple UPLC-MS/MS Assay of Rifampin in a Small Volume of Human Plasma.

Rifampin (RIF) is a typical cytochrome P450 (CYP) 3A inducer and inhibitor of organic anion transporting polypeptide (OATP) 1B1 to assess drug-drug interaction (DDI) via CYP3A or OATP1B1 in clinical settings. To ensure sufficient exposure of RIF in DDI studies, it is important to determine plasma RIF concentrations. In this study, we developed a simple RIF assay in a small volume of human plasma by ultraperformance liquid chromatography with tandem mass spectrometry. RIF in 0.02 mL of plasma was extracted using protein precipitation and separated on a reverse phase column under gradient elution of three mobile phases, where the mobile phase C containing 1% formic acid was exclusively used to reduce the carryover of RIF. RIF and the internal standard were detected by multiple reaction monitoring in positive-ion electrospray ionization. RIF was quantifiable at 0.025-10 μg/mL without the carryover issue. The intra- and inter-run assays confirmed the reproducibility of the assay. Stability assessments ensured that RIF in human plasma was stable for 6 h at room temperature and for 409 days at -15 °C or below. The assay was successfully applied to a pharmacokinetic study with successful incurred sample reanalysis.

New approach to rifampicin stability and first-line anti-tubercular drug pharmacokinetics by UPLC-MS/MS

Successful tuberculosis (TB) therapy requires achieving sufficient exposure to multiple drugs. Limited stability of several first-line anti-TB drugs might compromise reliable therapeutic drug monitoring (TDM). We developed and validated a sensitive and selective UPLC-MS/MS method for simultaneous quantification of isoniazid (INH), pyrazinamide (PZA), rifampicin (RIF), its metabolite 25-desacetylrifampicin and degradation products: rifampicin quinone and 3-formyl-rifampicin. Analysis was completed from a very small plasma volume (20 µL) using only protein precipitation with methanol. Chromatographic separation was achieved on a Kinetex Polar C18 column (2.6 µm; 150 × 3 mm) with a mobile phase consisting of 5 mM ammonium acetate and acetonitrile, both containing 0.1 % formic acid, in gradient elution. The analytes were detected using a positive ionization mode by multiple reaction monitoring. The LLOQ for RIF and its degradation products was 0.1 µg/mL, 0.05 µg/mL for INH, and 0.2 µg/mL for PZA. The method was validated based on the FDA guidance. The application of the method was confirmed in the analysis of RIF, INH, and PZA, as well as RIF metabolism/degradation products in plasma samples of patients with TB. Based on the detailed stability study of the analyzed compounds at various storage conditions, we proposed recommendations for handling the plasma and serum samples in TDM and other pharmacokinetic studies.

A Novel Method for Determination of Cyclobenzaprine in the Different Matrixes by UHPLC-DAD: Application to Real Human Plasma and Pharmaceutical Formulations.

This study presents a novel and efficient method for determining of cyclobenzaprine (CBP) in human plasma and tablets using simple liquid-liquid microextraction and ultra-high performance liquid chromatography-diode-array detector. The developed method was optimized and validated for selectivity, linearity, precision, accuracy, limit of detection (LOD) and limit of quantification (LOQ). The chromatographic separation was achieved using a C18 column with a mobile phase consisting of a mixture of deionized water containing 0.1% TFA and methanol (30:70, v:v) at a flow rate of 1.0mL/min. The extraction process provided high-efficiency recovery of CBP with a small plasma volume (%94.3). The method showed good linearity within the concentration range of 0.005-10μg/mL, with a correlation coefficient of 0.999. The LOD and LOQ values were found to be 0.0013 and 0.005μg/mL, respectively. The intra- and inter-day %RSD were <8%, and %RE were ranged from -0.50 to 0.01%. The proposed method was successfully applied to the analysis of CBP in real human plasma samples and tablets, indicating its applicability in clinical and pharmaceutical research. In conclusion, the simple, low cost, high sensitivity and rapid nature of this method make it an attractive option for the quantification of CBP in human plasma and pharmaceutical dosage forms.

Immunoaffinity‐Based Microfluidic Platform for Exosomal MicroRNA Isolation from Obese and Lean Mouse Plasma

AbstractA new way of intercellular communication has been recently demonstrated, consisting of the controlled release of small vesicles loaded with bioactive factors (proteins, lipids, and nucleic acids chiefly amongst them) to the extracellular compartment. Importantly, these extracellular vesicles (EVs), including microvesicles and exosomes, regulate various physiological processes and, when disturbed, may contribute to the onset and progression of many diseases. Hence, they can be exploited as informative biomarkers to diagnose and monitor pathological conditions, including type 2 diabetes and associated metabolic disease. However, currently available techniques to isolate EVs lack reproducibility, effectiveness, and rapidity and require high amounts of starting samples, limiting their introduction in clinical practice. The objective of this work is to use a simple and easy‐to‐use microfluidic platform for capturing and quantifying a specific subpopulation of EVs from a small volume of plasma. As a proof‐of‐concept, the platform is tested with murine plasma. An analysis of the microRNA (miRNA) content of the isolated EVs is performed, detecting significant differences when comparing lean and obese mice. Thus, the device offers an easy, straightforward system to detect and analyze plasma‐derived EVs in the everyday clinical setting.

Depletion of abundant plasma proteins for extracellular vesicle proteome characterization: benefits and pitfalls

Blood extracellular vesicles (EVs) play essential roles in cell–cell communication and their molecular cargo is a promising source of disease biomarkers. However, proteomic characterization of plasma-derived EVs is challenged by the presence of highly abundant plasma proteins, which limits the detection of less abundant proteins, and by the low number of EVs in biological fluids. The aim of this study was to investigate if the removal of abundant plasma proteins prior to EV isolation could improve plasma-derived EV characterization by LC–MS/MS and expand the proteome coverage. Plasma depletion was performed using a single-use spin column and EVs were isolated from only 100 µL of non-depleted and depleted plasma by size exclusion chromatography. Afterwards, EVs were characterized by nanoparticle tracking analysis and mass spectrometry–based proteomics using a data-independent acquisition approach. Depleted plasma-derived EVs had higher particle concentrations and particle-to-protein ratios. Depletion did increase the protein coverage with a higher number of identifications in EVs from depleted plasma (474 proteins) than from non-depleted (386 proteins). However, EVs derived from non-depleted plasma carried a slightly higher number of common EV markers. Overall, our findings suggest that plasma depletion prior to EV isolation by size exclusion chromatography provides higher yield and protein coverage, but slightly lower identification of EV markers. This study also showed the possibility to characterize the proteome of EVs derived from small plasma volumes, encouraging the clinical feasibility of the discovery of EV biomarkers.

Effects of Autologous and Homologous Platelet Rich Plasma on Full Thickness Autologous Skin Graft in Dogs

Background: Wound healing is a complicated mechanism that includes inflammatory, proliferative and remodelling stages. Platelet rich plasma (PRP) is a small volume of blood plasma fortified with platelets and growth factors that enhance the healing by stimulating angiogenesis and formation of granulation tissue. Methods: The present study was performed to evaluate the effect of autologous and homologous platelet rich plasma on full thickness dermatological reconstructive surgery in dogs. The dogs were divided in two groups A and B, each with four clinical cases. In groups A and B, autologous and homologous PRP was used respectively as skin graft augmentation. The macroscopic parameters of the study included colour, edema, exudation and histopathological parameters included acute inflammation, fibroblast proliferation and granulation tissue formation. All these observations were made on days 3, 7 and 14 post-operatively. Result: On the basis of findings of this study, it was concluded that autologous PRP is a better graft healing promoter in terms of self-limiting acute inflammation, fibroblast proliferation, granular tissue and early healing of graft as compared to homologous PRP.

Absolute pharmacokinetics of heparin in primates

Heparin is a commonly used anticoagulant drug, derived from the tissues of animals including pigs, cows, and sheep. Measuring heparin concentration in plasma is challenging due to its complex molecular structure. Existing methods rely on measuring heparin's anticoagulant activity, which provides pharmacodynamic (PD) data but not pharmacokinetic (PK) data, measuring concentration over time. To overcome this limitation, we used liquid chromatography-mass spectrometry (LC-MS) and the multiple reaction monitoring (MRM) method to directly measure heparin's concentration in non-human primates after administering porcine, bovine, and ovine heparin. A protocol was developed to enable an MRM method for application to small plasma volumes without purification. The PK data obtained from LC-MS are then compared with the data obtained using the Heparin Red assay and the PD data determined using biochemical clinical assays. Results showed that LC-MS and Heparin Red assay measurements closely correlated with unfractionated heparin's biological activities, supporting the use of mass spectra and dye-binding assays to determine heparin levels in plasma. This study builds a way for the measurement of heparin concentration in plasma, which could lead to an improved understanding of heparin's metabolism and dosing safety.

Small Volume Plasma Exchange as an Alternative to Conventional Plasma Exchange and Intravenous Immunoglobulin for Myasthenic Crisis: A Case Report

Myasthenic crisis is a life-threatening condition. At times it manifests as the initial presentation of the underlying myasthenia gravis. Rapidly acting therapies for treatment of this condition are plasma exchange and intravenous immunoglobulin. We report a case of myasthenic crisis in a young female, presenting with respiratory failure and bulbar symptoms. She had significantly raised titres of anti-acetylcholine receptor antibody. She was treated with multiple sessions of small volume plasma exchange. This modification of conventional plasma exchange significantly reduces costs and is potentially an effective alternative to conventional plasma exchange and intravenous immunoglobulin in resource-poor settings.

Longitudinal perturbations of plasma nuclear magnetic resonance profiles in neonatal encephalopathy.

Neonatal encephalopathy (NE) is a major cause of mortality and severe neurological disability in the neonatal period and beyond. We hypothesized that the degree of brain injury is reflected in the molecular composition of peripheral blood samples. A sub-cohort of 28 newborns included in the HYPOTOP trial was studied. Brain injury was assessed by magnetic resonance imaging (MRI) once per patient and neurodevelopment at 24 months of age was evaluated using the Bayley III Scales of Infant and Toddler Development. The nuclear magnetic resonance (NMR) profile of 60 plasma samples collected before, during, and after cooling was recorded. In total, 249 molecular features were quantitated in plasma samples from newborns and postnatal age showed to affect detected NMR profiles. Lactate, beta-hydroxybutyrate, pyruvate, and three triglyceride biomarkers showed the ability to discern between different degrees of brain injury according to MRI scores. The prediction performance of lactate was superior as compared to other clinical and biochemical parameters. This is the first longitudinal study of an ample compound panel recorded by NMR spectroscopy in plasma from NE infants. The serial determination of lactate confirms its solid position as reliable candidate biomarker for predicting the severity of brain injury. The use of nuclear magnetic resonance (NMR) spectroscopy enables the simultaneous quantitation of 249 compounds in a small volume (i.e., 100 μL) of plasma. Longitudinal perturbations of plasma NMR profiles were linked to magnetic resonance imaging (MRI) outcomes of infants with neonatal encephalopathy (NE). Lactate, beta-hydroxybutyrate, pyruvate, and three triglyceride biomarkers showed the ability to discern between different degrees of brain injury according to MRI scores. Lactate is a minimally invasive candidate biomarker for early staging of MRI brain injury in NE infants that might be readily implemented in clinical guidelines for NE outcome prediction.

Determination of Catecholamines in a Small Volume (25μL) of Plasma from Conscious Mouse Tail Vein.

The determination of plasma catecholamine levels is commonly used as a measure of the sympathetic nervous system's response to stress and is highly important for diagnosis, therapy, and prognosis of cardiovascular diseases, catecholamine-secreting tumors arising from the chromaffin cells of the sympathoadrenal system, and affective disorders. Diseases in which catecholamines are significantly elevated include pheochromocytoma, Parkinson's disease, Alzheimer's disease, neuroblastoma, ganglioneuroblastoma, von Hippel-Lindau disease, baroreflex failure, chemodectina (nonchromaffin paraganglioma), and multiple endocrine neoplasia. Plasma norepinephrine levels provide a guide to prognosis in patients with stable, chronic, and congestive heart diseases. The method described here for the determination of plasma catecholamines is based on the principle that plasma catecholamines are selectively adsorbed on acid-washed alumina at pH 8.7 and then eluted at a pH between 1.0 and 2.0. Upon injection, catecholamines in elutes were separated by a reversed phase C-18 column. After separation, the catecholamines present within the mobile phase enter the electrochemical detector. Electrochemical detection occurs because electroactive compounds oxidize at a certain potential and thereby liberate electrons that create measurable current. Catecholamines readily form quinones under these conditions, get oxidized, release two electrons, and create current. The electrochemical detector detects this electrical current that linearly correlates to the catecholamine concentration loaded into the ultra-performance liquid chromatography instrument. A 15-min mixing time during the adsorption and desorption steps was found to be optimal. If the washing step was omitted, the catecholamines could not be eluted from the acid-washed alumina. To prevent dilution, the alumina had to be centrifuged and not aspirated to dryness after the washing step. We report here that by changing the range in the electrochemical detector, plasma catecholamines were measured with only 12.5μL of plasma and more reliably with 25μL of plasma. The detection limit was 1ng/mL. This assay method is very useful as blood can be collected from the tail vein in a conscious mouse and the same mouse can be used for time-dependent or age-dependent studies.

Microfluidic Acoustic Method for High Yield Extraction of Cell-Free DNA in Low-Volume Plasma Samples.

Cell-free DNA has many applications in clinical medicine, in particular in cancer diagnosis and cancer treatment monitoring. Microfluidic-based solutions could provide solutions for rapid, cheaper, decentralized detection of cell-free tumoral DNA from a simple blood draw, or liquid biopsies, replacing invasive procedures or expensive scans. In this method, we present a simple microfluidic system for the extraction of cell-free DNA from low volume of plasma samples (≤500μL). The technique is suitable for either static or continuous flow systems and can be used as a stand-alone module or integrated within a lab-on-chip system. The system relies on a simple yet highly versatile bubble-based micromixer module whose custom components can be fabricated with a combination of low-cost rapid prototyping techniques or ordered via widely available 3D-printing services. This system is capable of performing cell-free DNA extractions from small volumes of blood plasma with up to a tenfold increase in capture efficiency when compared to control methods.

Evaluation of Platelet Rich Plasma for Treatment of Female Pattern Hair Loss: A Placebo-Controlled Case Study

Background: Platelet Rich Plasma (PRP) is an autologous concentration of human platelets contained in a small volume of plasma, has been proposed as a potential adjuvant therapy to Female Pattern Hair Loss (FPHL). Despite the widespread use of PRP in numerous fields of medicine, there have been few studies that investigated the clinical efficacy of PRP in FPHL. Methods: Fourteen female patients, age ranged from 20-45 years, diagnosed with female pattern hair loss were enrolled in this single-blinded randomized placebo-controlled study. Fourteen patients were divided randomly into two groups: Group 1 were injected with PRP using insulin syringe and group 2 were injected with normal saline as placebo. All patients were followed at 3 and 6 months after the last treatment sessions. Of the total subjects enrolled, on ten subjects completed the study. In total, 7 (70%) individuals received PRP and 3 (30%) received placebo. During all the treatment sessions, there were no severe adverse events reported. The study yielded investigator, subject and photographic assessments. Results: On the basis of the independent-blinded investigator assessment of change in the patient’s scalp hair growth from baseline, treatment in PRP group demonstrated as scale 1 improvement in 5 subjects (26-50%) and scale 2 improvement in 2 subjects (51-75%) at the final visit as compared to baseline (Fig. 1,2). In contrast, in the placebo group were rated as scale 0 improvement (0-25%). Conclusion: PRP injection for FPHL is a simple, cost-effective and feasible treatment option with good safety profile. However more randomized and multicentric trials with a large number of patients will be required to prove the validity of these results, to obtain these answers and to get more robust statistical results.

Ocular surgical use of autologous platelet‐rich plasma

AbstractEye platelet‐rich plasma (E‐PRP) concentrates platelets in a small volume of plasma which contains a high concentration of important growth factors and cell adhesion molecules. These cell adhesion molecules and growth factors occupy a major role in wound healing and enhance the physiological procedure at the site of the injury or the surgery. Platelet‐rich plasma in the form obtained in ophthalmology, E‐PRP, is a reliable and effective surgical coadjuvant to promote corneal wound healing in severe corneal ulcers and corneal perforations and may be associated with other ocular surface reconstruction procedures.Actually, platelet‐rich plasma (E‐PRP) offers new surgical perspectives in many fields of medicine helping in wound healing, it represents a greater similarity to the natural healing process as a composite of multiple growth factors, is safe due to its autologous nature and has both mitogenic and chemotactic properties. E‐PRP functions as a drug delivery system and a tissue sealant.The α‐granules within these platelets liberate platelet‐derived growth factors, platelet‐derived growth factor BB (PDGF‐BB), transforming growth factor β1 (TGF‐β1), epidermal growth factor (EGF), and vascular endothelial growth factor A (VEGF‐A) which have an important anti‐inflammatory action. It has many ocular surface applications such as in dry eye, dormant corneal ulcers, and it is also used surgically as a sutured clot of autologous fibrin membrane in big neurotrophic corneal ulcers or imminent/already perforated eyes.There are new uses of E‐PRP such as the intracameral application of E‐PRP for different purposes or injection into the lacrimal glands. All of them with the aim of improving the functionality of damaged eye tissue.