Treatment with platelet-rich plasma of surgically related dormant corneal ulcers

Blood-Derived Eye Drops for the Treatment of Corneal Neuropathic Pain

Blood-derived preparations, including autologous or allogenic serum, umbilical cord serum/plasma, and platelet-rich plasma eye drops, contain various growth factors, cytokines, and immunoglobulins that resemble natural tears. These components play important roles in corneal cell migration, proliferation, and wound healing. Blood-derived eye drops have demonstrated clinical effectiveness across a spectrum of ocular surface conditions, encompassing dry eye disease, Sjögren's syndrome, graft-versus-host disease, and neuropathic corneal pain (NCP). Currently, management of NCP remains challenging. The emergence of blood-derived eye drops represents a promising therapeutic approach. In this review, we discuss the benefits and limitations of different blood-derived eye drops, their mechanisms of action, and treatment efficacy in patients with NCP. Several studies have demonstrated the clinical efficacy of autologous serum eye drops in relieving pain and pain-like symptoms, such as allodynia and photoallodynia. Corneal nerve parameters were also significantly improved, as evidenced by increased nerve fiber density, length, nerve reflectivity, and tortuosity, as well as a decreased occurrence of beading and neuromas after the treatment. The extent of nerve regeneration correlated with improvement in patient-reported photoallodynia. Cord plasma eye drops also show potential for symptom alleviation and corneal nerve regeneration. Future directions for clinical practice and research involve standardizing preparation protocols, establishing treatment guidelines, elucidating underlying mechanisms, conducting long-term clinical trials, and implementing cost-effective measures such as scaling up manufacturing. With ongoing advancements, blood-derived eye drops hold promise as a valuable therapeutic option for patients suffering from NCP.

Neurophysiology of corneal neuropathic pain and emerging pharmacotherapeutics

The altered activity generated by corneal neuronal injury can result in morphological and physiological changes in the architecture of synaptic connections in the nervous system. These changes can alter the sensitivity of neurons (both second-order and higher-order projection) projecting pain signals. A complex process involving different cell types, molecules, nerves, dendritic cells, neurokines, neuropeptides, and axon guidance molecules causes a high level of sensory rearrangement, which is germane to all the phases in the pathomechanism of corneal neuropathic pain. Immune cells migrating to the region of nerve injury assist in pain generation by secreting neurokines that ensure nerve depolarization. Furthermore, excitability in the central pain pathway is perpetuated by local activation of microglia in the trigeminal ganglion and alterations of the descending inhibitory modulation for corneal pain arriving from central nervous system. Corneal neuropathic pain may be facilitated by dysfunctional structures in the central somatosensory nervous system due to a lesion, altered synaptogenesis, or genetic abnormality. Understanding these important pathways will provide novel therapeutic insight.

The Preventive Effects of Platelet-Rich Plasma Against Knee Osteoarthritis Progression in Rats

BACKGROUND

In recent years, the intra-articular administration of platelet-rich plasma (PRP), a novel therapeutic strategy for knee osteoarthritis (KOA), has gained attention. However, the efficacy of PRP in inhibiting degenerative joint changes remains unclear. The current study aimed to evaluate the therapeutic effect of the intra-articular administration of PRP in rats with induced KOA.

MATERIALS AND METHODS

PRP was prepared from the whole blood of nine-week-old male Wistar rats via centrifugation at 25°C, 200 × g, for seven minutes. KOA was induced in the right knees of the rats via destabilization of the medial meniscus (DMM) surgery. The animals were divided into the control, sham, DMM, and DMM + PRP groups (n = 5 each). The rats in the DMM + PRP group received 50 μL of intra-articular PRP in the right knee joint four weeks after surgery. The rotarod test was conducted to assess locomotive function. Eight weeks after DMM surgery, the degree of medial meniscus extrusion was measured via computed tomography (CT) images on the right knee. Then, a histological analysis of the harvested knees was conducted. KOA progression was assessed using the Osteoarthritis Research Society International (OARSI) score. The number of multinucleated tartrate-resistant acid phosphatase (TRAP)-positive osteoclasts in the subchondral bone was counted via histological analysis.

RESULTS

The degree of medial meniscus extrusion did not significantly differ between the DMM and DMM + PRP groups. Similarly, there were no significant differences in the walking time based on the rotarod test between the DMM and DMM + PRP groups. However, the DMM group had a significantly higher OARSI score than the DMM + PRP group. The number of TRAP-positive osteoclasts in the subchondral bone of the DMM group increased over time, peaking four weeks after surgery. The DMM + PRP group had a higher number of TRAP-positive osteoclasts in the subchondral bone than the control group. However, there was no significant difference between the number of TRAP-positive osteoclasts between the DMM group and the control and sham groups.

CONCLUSION

The intra-articular administration of PRP may inhibit KOA progression in a rat model, especially in the articular cartilage degradation and osteophyte formation. The results can provide further evidence about the efficacy of PRP against KOA progression and can contribute to the current practice of healthcare professionals based on accurate knowledge.

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

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

Development of a new plasma rich in growth factors membrane with improved optical properties

PURPOSE

The aim of the present work was to develop a fibrin membrane using plasma rich in growth factors (PRGF) technology with improved optical properties to be used for the treatment of ocular surface diseases.

BASIC PROCEDURES

Blood was drawn from three healthy donors, and the volume of PRGF obtained from each donor was divided into two main groups: i) PRGF or ii) platelet-poor plasma (PPP). Each membrane was then used pure or diluted to 90 %, 80 %, 70 %, 60 % and 50 %. The transparency of each of the different membranes was evaluated. The degradation and morphological characterization of each membrane was also performed. Finally, a stability study of the different fibrin membranes was performed.

MAIN FINDINGS

The transmittance test showed that the fibrin membrane with the best optical characteristics was obtained after removal of platelets and dilution of fibrin to 50 % (50 % PPP). No significant differences (p > 0.05) were observed between the different membranes in the fibrin degradation test. The stability test showed that the membrane at 50 % PPP retains its optical and physical characteristics after storage at - 20 °C for 1 month compared to storage at 4 °C.

PRINCIPAL CONCLUSIONS

The present study describes the development and characterization of a new fibrin membrane with improved optical characteristics while maintaining mechanical and biological characteristics. The physical and mechanical properties of the newly developed membrane are preserved after storage for at least 1 month at - 20 °C.

Therapeutic Effect of Platelet-Rich Plasma Improves Bladder Overactivity in the Pathogenesis of Ketamine-Induced Ulcerative Cystitis in a Rat Model

The present study attempted to elucidate whether intravesical instillation of platelet-rich plasma (PRP) could decrease bladder inflammation and ameliorate bladder hyperactivity in ketamine ulcerative cystitis (KIC) rat model. Female Sprague Dawley (S-D) rats were randomly divided into control group, ketamine-treated group, ketamine with PRP treated group, and ketamine with platelet-poor plasma (PPP) treated group. Cystometry and micturition frequency/volume studies were performed to investigate bladder function. The morphological change of bladder was investigated by Mason’s trichrome staining. Western blotting analysis were carried out to examine the protein expressions of inflammation, urothelial differentiation, proliferation, urothelial barrier function, angiogenesis and neurogenesis related proteins. The results revealed that treatment with ketamine significantly deteriorated bladder capacity, decreased voiding function and enhanced bladder overactivity. These pathological damage and interstitial fibrosis may via NF-κB/COX-2 signaling pathways and muscarinic receptor overexpression. PRP treatment decreased inflammatory fibrotic biosynthesis, attenuated oxidative stress, promoted urothelial cell regeneration, and enhanced angiogenesis and neurogenesis, thereafter recovered bladder dysfunction and ameliorate the bladder hyperactivity in KIC rat model. These findings suggested that the PRP therapy may offer new treatment options for those clinical KIC patients.

Topical Therapeutic Options in Corneal Neuropathic Pain

Purpose of Review: Corneal neuropathic pain can be difficult to treat, particularly due to its lack of response to standard dry eye therapies. We describe a variety of topical therapeutic options that are available to treat corneal neuropathic pain with a significant or primary peripheral component. We also describe possible mechanisms of action for such topical therapies.

Recent Findings: Topical corticosteroids and blood-derived tear preparations can be helpful. Newer therapies, including topical lacosamide and low-dose naltrexone are emerging therapeutic options that may also be considered.

Summary: Corneal neuropathic pain with a significant peripheral component may be managed with a variety of topical therapeutic options.

Platelet rich plasma effectiveness in bowel anastomoses: A systematic review

BACKGROUND

Anastomotic leak constitutes a major problem in abdominal surgery. Technical insufficiency, topical or systemic factors contribute to disrupted healing of the performed bowel anastomosis and result in anastomosis leakage, with detrimental effects on patient postoperative outcomes. Despite the investigation of several factors and the invention of protective materials, the ideal agent to prevent anastomotic leaks is yet to be determined.

AIM

To study the effect of platelet rich plasma (PRP) on the healing of bowel anastomoses.

METHODS

A systematic literature search was performed in PubMed, EMBASE, and Scopus databases to identify studies investigating the effect of PRP application on bowel anastomosis.

RESULTS

Eighteen studies were eligible with a total population of 712 animals including rats (14 studies), rabbits (2 studies) and pigs (2 studies). No postoperative complications were reported following PRP application. Fourteen out of 18 studies reported a statistically significant higher anastomosis bursting pressure in PRP groups compared to control either in healthy animals or animal models with underlying condition or intervention, such as intraperitoneal chemotherapy or peritonitis. Similar results were reported by ten studies in terms of tissue hydroxyproline levels. One study reported significant increase in collagen deposition in PRP groups. PRP application resulted in significantly decreased inflammatory cell infiltration in the presence of peritonitis or intraperitoneal chemotherapy (6 studies).

CONCLUSION

The application of PRP is associated with improved bowel anastomosis outcomes, especially in animal models having an underlying condition affecting the normal healing process. PRP application seems to augment the normal healing process under these circumstances. However, further studies are needed to investigate the potential role of PRP on bowel anastomosis healing, especially in clinical settings.

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.

Effect of Platelet-Rich Plasma on Corneal Epithelial Healing after Phototherapeutic Keratectomy: An Intraindividual Contralateral Randomized Study

Purpose

To assess the effect of platelet-rich plasma (PRP) on the healing response of the corneal epithelium in eyes undergoing phototherapeutic keratectomy (PTK).

Methods

We prospectively examined 20 eyes of 10 patients undergoing bilateral PTK for granular corneal dystrophy or band keratopathy. Patients were randomly assigned to start topical administration of PRP ophthalmic suspension (PRP group) or artificial tears (control group) 4 times daily for 2 weeks. Immediately, 1, and 2 days, and 1 week after PTK, we quantitatively measured the staining area of the corneal epithelium, using slit-lamp photography. We also determined the subjective symptoms and the satisfaction, using the visual analogue system (VAS).

Results

The staining area in the PRP group was significantly smaller than that in the control group on days 1 and 2 (Wilcoxon signed-rank test, p = 0.022 and p = 0.017, respectively), but not on day 7 (p = 0.317). The recovery rate of the corneal epithelium in the PRP group was significantly higher than that in the control group on days 1 and 2 (p = 0.022 and p = 0.017, respectively), but not on day 7 (p = 0.317). We found no significant differences in pain (p = 0.139), foreign body sensation (p = 0.108), epiphora (p = 1.000), or satisfaction (p = 0.295), between the two groups. Postoperative complications did not occur in any of the eyes in the study.

Conclusions

The PRP treatment was effective for enhancing corneal epithelial recovery in the early postoperative period, without significant adverse events, in post-PTK-treated eyes, suggesting that it may hold promise as one of the treatment options for treating such postsurgical patients.

Cell and Cell Free Therapies in Osteoarthritis

Osteoarthritis (OA) is the most common articular disease in adults and has a current prevalence of 12% in the population over 65 years old. This chronic disease causes damage to articular cartilage and synovial joints, causing pain and leading to a negative impact on patients' function, decreasing quality of life. There are many limitations regarding OA conventional therapies-pharmacological therapy can cause gastrointestinal, renal, and cardiac adverse effects, and some of them could even be a threat to life. On the other hand, surgical options, such as microfracture, have been used for the last 20 years, but hyaline cartilage has a limited regeneration capacity. In recent years, the interest in new therapies, such as cell-based and cell-free therapies, has been considerably increasing. The purpose of this review is to describe and compare bioregenerative therapies' efficacy for OA, with particular emphasis on the use of mesenchymal stem cells (MSCs) and platelet-rich plasma (PRP). In OA, these therapies might be an alternative and less invasive treatment than surgery, and a more effective option than conventional therapies.

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

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

Combined Platelet Rich Plasma and Amniotic membrane in the treatment of Perforated Corneal Ulcers

PURPOSE

To report the outcomes of using synthetic amniotic membrane with platelet rich plasma for the primary management of corneal perforations.

SETTING

Ophthalmology department. Faculty of Medicine, Minia University, Minia, Egypt.

METHODS

A case series of 10 patients diagnosed with corneal perforation underwent emergency surgical procedure for repair of the perforation through the implantation of synthetic amniotic membrane with platelet-rich plasma clot under it and the application of platelet-rich plasma eye drops, with a follow up period of up to 4 weeks.

RESULTS

All cases demonstrated formation of adequate intraocular pressure digitally, within the first 7 days, and all cases showed complete sealing of the corneal perforation within the 4 weeks follow up period, mild symptoms were reported only in the 1^st postoperative week like foreign body sensation and lacrimation. 3 of the treated patients underwent penetrating keratoplasty after 6 months with satisfactory visual outcomes.

CONCLUSION

The combination of amniotic membrane implant and platelet rich plasma in both the clot and eye drop forms is an effective and easy accessible method for the primary management of corneal perforations.

Comparison of Allogeneic Platelet-rich Plasma With Autologous Platelet-rich Plasma for the Treatment of Diabetic Lower Extremity Ulcers

Autologous platelet-rich plasma (au-PRP) has been widely used for the management of refractory chronic wounds. However, patients with diabetic lower extremity ulcers (DLEUs) usually have complicated clinical conditions, and the utility of au-PRP is limited. In this study, the feasibility, effectiveness, and safety of allogeneic platelet-rich plasma (al-PRP) and au-PRP were investigated and compared in the treatment of DLEUs. A total of 75 in-patients with type 2 diabetes were assigned to the al-PRP group (n = 20), au-PRP group (n = 25), and conventional wound therapeutic (CWT) group (n = 30) matched by the ankle brachial index and ulcer size from December 2015 to August 2018. Based on metabolic and nutritional regulation, infective control, and topical wound management, al-PRP, au-PRP, and CWT were administered to each group, respectively. Evaluation of treatment outcomes was determined by the parameters of wound healing and adverse reactions. The therapeutic times and average concentration of platelets were not significantly different between the au-PRP and al-PRP groups. The wound healing times of the al-PRP group (56.9 ± 29.22 d) and au-PRP group (55.6 ± 33.8 d) were significantly shorter than those of the CWT group (88.0 ± 43.4 d) (P < 0.01), but there was no significant difference between the groups with PRP treatment. Although there was no significant difference in the daily healing area among all groups (P > 0.05), the trend of the healing rate in the al-PRP group (16.77 ± 12.85 mm²), au-PRP group (14.31 ± 18.28 mm²), and CWT group (9.90 ± 8.51 mm²) gradually decreased. No obvious adverse reactions (fever, edema, pain, skin itching, rash, or other sensory abnormalities) were observed in either the au-PRP or the al-PRP groups. Both al-PRP and au-PRP could effectively and safely promote wound healing in patients with DLEUs. Alternatively, al-PRP could be used for DLEUs as an off-the-shelf solution when au-PRP is limited.

Corneal Ulcer in Dogs and Cats: Novel Clinical Application of Regenerative Therapy Using Subconjunctival Injection of Autologous Platelet-Rich Plasma

Background: Corneal ulcer could be a major source of distress in small animals, with many contributing agents. In recent years, few studies evaluated the efficacy of platelet-rich plasma (PRP) in healing corneal ulcers. Aim: This study aimed to assess the ability of subconjunctival injection of autologous PRP in the treatment of corneal ulcers in dogs and cats as well as estimate the expression of matrix metalloproteinase (MMP)-2, MMP-9, and oxidative stress biomarkers in these patients. Methods: A total number of 28 animals (16 cats and 12 dogs) were enrolled in this study. Each animal was subjected to clinical, neurologic, and ophthalmic examinations where the type of ulcer was documented. Tear samples were collected for evaluation of oxidative biomarkers and MMPs; conjunctival swabs were taken to identify the involved organism. PRP was prepared from each animal and given as subconjunctival injection; numbers of injections were done according to case response. Clinical follow-up was done and documented for each case. Results: In cat patients, female and Persian cats were most affected; unilateral and superficial ulcers were most recorded. In male dogs, unilateral, and superficial ulcers were most recorded. FHV-1 was most identified in cats, while Staphylococcus aureus was most identified in dogs. Numbers of injections needed to achieve healing were recorded, with 50% of dogs needing two injections with 1-week intervals and 50% of cats needed three injections with 1-week intervals. Alterations in both oxidative biomarkers and MMPs were recorded in affected animals. Conclusion: The use of autologous PRP as a subconjunctival injection in treating corneal ulcers in dogs and cats is effective. The number of injections is the case and corneal ulcer type-dependent. Clinical Significance: Autologous PRP as a subconjunctival injection in treating corneal ulcer is a relatively cheap, safe method and can be done in the clinical setting.

Novel applications of platelet concentrates in tissue regeneration (Review)

Numerous studies have explored the suitability of biocompatible materials in regenerative medicine. Platelet concentrates are derived from centrifuged blood and are named according to their biological characteristics, such as platelet-rich plasma, platelet-rich fibrin and concentrated growth factor. Platelet concentrates have gained considerable attention in soft and hard tissue engineering. Indeed, multiple components of autologous platelet concentrates, such as growth factors, fibrin matrix and platelets, serve essential roles in wound healing. Current studies are focused on cutting-edge strategies to meet the requirements for tissue restoration by improving the properties of autologous platelet concentrates. In the present review, applications of platelet concentrates for tissue engineering are discussed, presenting a selection of recent advances and novel protocols. In addition, several aspects of these strategies, such as the advantages of lyophilized platelet concentrates and the combination of platelet concentrates with biomaterials, stem cells or drugs are discussed. The present review aims to summarize novel strategies using platelet concentrates to improve the outcomes of wound healing.

Comparison of Two Preparation Methods for Platelet-Rich Plasma Eye Drops for Release of Growth Factors and De-Epithelization Rabbit Model

Purpose

To compare two platelet-rich plasma (PRP) preparation methods (double spin (D-PRP) and TriCell PRP (T-PRP)) for eye drops, concentration yields of platelets and other cells, release of growth factors, and efficacy of the de-epithelization rabbit model.

Methods

PRP was extracted by D-PRP and T-PRP from 30 ml blood from healthy adults. After extraction, platelets and leukocytes were counted. D-PRP and T-PRP were preserved during A: 1 h storage at room temperature, B: 1 h storage at −20°C, C: 24 h storage at 4°C, and D: 24 h storage at −20°C. Platelet-derived growth factor (PDGF) was measured. Freezing/thawing PRP eye drops and control were instilled in the de-epithelization rabbit model four times per day for 5 days. Histology was compared between eyes treated with control, D-PRP, and T-PRP.

Results

14 ml of D-PRP and 4 ml of T-PRP were extracted from 30 ml whole blood samples. D-PRP and T-PRP had 41.36 ± 8.43 × 10⁴ and 67.02 ± 13.55 × 10⁴ platelets and 0.41 ± 0.24 × 10³/ml and 10.09 ± 4.29 × 10³/ml leucocytes, respectively. In the four storage methods, PDGF concentrations in T-PRP were higher than those in D-PRP eye drops. Freezing/thawing D-PRP and T-PRP increased PDGF concentrations. Histology showed corneal epithelium thickness in T-PRP-treated eyes after healing (38.41 ± 9.10 μm) was significantly higher than that in control-treated (27.77 ± 4.76 μm) and D-PRP-treated eyes (18.32 ± 3.14 μm) (P < 0.05). There was no corneal damage with inflammation in corneal stroma and epithelium of all tested groups. Electron microscopy revealed strong adhesion between cell junctions in T-PRP-treated eyes.

Conclusions

Freezing/thawing of PRP extracted with the T-PRP kit may result in high platelet and leukocyte concentration and produce high PDGF concentration. PRP eye drops including leucocytes could increase thickness of corneal epithelium without corneal inflammation.

Effects of platelet-rich plasma on the healing of sternal wounds: A meta-analysis

Sternal wound infection (SWI) is a devastating complication after cardiac surgery. Platelet-rich plasma (PRP) may have a positive impact on sternal wound healing. A systematic review with meta-analyses was performed to evaluate the clinical effectiveness of topical application of autologous PRP for preventing SWI and promoting sternal wound healing compared to placebo or standard treatment without PRP. Relevant studies published in English or Chinese were retrieved from the Cochrane Central Register of Controlled Trials (The Cochrane Library), PubMed, Ovid EMBASE, Web of Science, Springer Link, and the WHO International Clinical Trials Registry Platform (ICTRP) using the search terms "platelet-rich plasma" and "sternal wound" or "thoracic incision." References identified through the electronic search were screened, the data were extracted, and the methodological quality of the included studies was assessed. The meta-analysis was performed for the following outcomes: incidence of SWI, incidence of deep sternal wound infection (DSWI), postoperative blood loss (PBL), and other risk factors. In the systematic review, totally 10 comparable studies were identified, involving 7879 patients. The meta-analysis for the subgroup of retrospective cohort studies (RSCs) showed that the incidence of SWI and DSWI in patients treated with PRP was significantly lower than that in patients without PRP treatment. However, for the subgroup of randomized controlled trials (RCTs), there was no significant difference in the incidence of SWI or DSWI after intervention between the PRP and control groups. There was no significant difference in PBL in both RCTs and RSCs subgroups. Neither adverse reactions nor in-situ recurrences were reported. According to the results, PRP could be considered as a candidate treatment to prevent SWI and DSWI. However, the quality of the evidence is too weak, and high-quality RCTs are needed to assess its efficacy on preventing SWI and DSWI.

Human Platelets and Derived Products in Treating Ocular Surface Diseases - A Systematic Review

Human platelet products have emerged as an alternative treatment for a range of ocular surface diseases such as dry eye and corneal ulceration. With significant therapeutic potential and increasing popularity, this study aimed to conduct a systematic review to detail the various production methods involved in generating platelet-derived products, compare and analyze clinical findings across available studies, and disseminate the relative advantages, limitations, and challenges of using platelet products to treat ocular surface disease. Thirty-eight clinical studies were identified, excluding studies conducted in animals and non-English language. Studies reported clinical outcomes, which included ocular surface disease index, best-corrected visual acuity, and corneal fluorescein staining. Most clinical studies reported improved patient signs and symptoms with an increasing variety of human platelet products including platelet rich plasma eye drops, human platelet lysate and platelet gels. However, due to variations in production methods, and study designs as well as confusing terminology, it was suggested that characterization of platelet products is needed for proper evaluation across studies.

Quantification of Growth Factors and Fibronectin in Diverse Preparations of Platelet-Rich Plasma for the Treatment of Ocular Surface Disorders (E-PRP)

Purpose

The purpose of this study was to quantify the presence of growth factors (GFs) and fibronectin in autologous platelet-rich plasma for topical ocular use (E-PRP) comparing their concentration when different preparation and preservation procedures were applied.

Methods

E-PRP was prepared with blood from healthy volunteers. The count of platelets, leukocytes, and red blood cells in the whole blood and E-PRP were performed. The concentration of the GFs platelet-derived growth factor BB (PDGF-BB), transforming growth factor β1 (TGF-β1), epidermal growth factor (EGF), vascular endothelial growth factor A (VEGF-A), and fibronectin was determined in each of the four procedures applied including fresh, frozen at −20°C for 3 months, fresh-spin, and frozen-spin at −20°C E-PRP samples. Posterior statistical analysis was performed to establish significant differences between groups and between GFs in relation to the amounts of platelets.

Results

Platelets in the E-PRP doubled in the number of basal values of whole blood (P ≤ 0.01). The blood cells in the E-PRP decreased drastically in red cells (99%) and also in leukocytes (82%). The concentration of PDGF-BB and EGF was significantly higher (P < 0.01) when the E-PRP samples were frozen at −20°C. However, no significant differences were observed for TGF-β1, VEGF-A, and fibronectin (P > 0.05). The concentration of GFs in the E-PRP did not necessarily correlate with the number of platelets.

Conclusions

Freezing the E-PRP for 3 months at −20°C increased the concentration of important proteins, such as PDGF-BB and EGF, and maintained the levels of others. These findings are essential because treatments, such as E-PRP, used by patients with ocular surface dysfunctions tend to prolong it in time. In addition, subsequent centrifugation of the E-PRP decreased the values of TFG-β1, but not the other GFs, which would allow adjusting the concentration of TFG-β1, as necessary. This procedure guarantees their correct conservation and viability.

Translational Relevance

This work demonstrates how clinical application can be improved by starting from basic research. The quantification of GFs and fibronectin in platelet-rich plasma (PRP) helps to clarify which is the best mode of preparation and preservation of PRP for clinical applications. This allows to optimize the product that is delivered to the patients as a treatment for the dysfunctions of the ocular surface, guaranteeing that the conservation does not affect at all the quality of the PRP that it is going to be used.

Comparison of platelet-rich plasma gel in the care of the pressure ulcers with the dressing with serum physiology in terms of healing process and dressing costs

This research was carried out with the aim of comparing the effects of platelet-rich plasma (PRP) gel and gas dressing with serum physiologic applied to stage II pressure ulcer in coccyx of patients for 2 months on healing process and dressing costs. This prospective randomised controlled experimental study was conducted with 60 patients hospitalised in the palliative care unit after surgery. The experimental group (n = 30) was dressed with platelet-rich plasma gel. The control group (n = 30) was treated with serum physiologic dressing. At the end of the 20th observation of the patients in the experimental group, it was found that the mean scores of area, exudate, and tissue type in pressure sores decreased statistically (P < .001). In the control group, no significant difference was found between the mean PUSH score at the end of the 20th observation (P > .05). The study showed that PRP gel had a positive effect on healing of stage II pressure ulcers with platelet-rich plasma gel dressings. In addition, when evaluated in the long term, it was concluded that platelet-rich plasma gel is easily accessible and less costly than serum physiological dressing.

Effects of autologous platelet-rich plasma coated sutures on intestinal anastomotic healing in rabbits

The objective of this study was to investigate the intestinal anastomotic healing enhancing effect of platelets-rich plasma (PRP) using PRP-coated sutures in a rabbit model. A total of 30 mature male rabbits were divided into 3 groups (10 rabbits per group). Group 1 received uncoated sutures, group 2 received sodium acetate-coated sutures, and group 3 received PRP-coated sutures. Polyglactin 910 (Vicryl, USA), size 4-0 was used in all groups. Five rabbits of each group were euthanized on day 3 following the surgery while the remaining 5 rabbits were euthanized on day 10. Gross evaluation of the anastomotic site in PRP-coated sutures group demonstrated significantly (P < 0.05) lower adhesion formation scores on both days 3 and 10 of the study while in the control groups, evidence of leakage at the anastomotic site was present along with signs of haemorrhage and local inflammation. On day 10 in the control groups, there were strands of strong adhesions between the ileum, colon and cecum with large amount of fibrin deposited at the site of the anastomosis. Tissues of the anastomotic site revealed a significant level of hydroxyproline on day 10 in PRP-coated sutures group compared with control groups. Histopathological evaluation revealed significantly (P < 0.05) less inflammatory infiltration, and more angiogenesis and collagen deposition on day 10 in PRP-coated sutures group compared to the control groups. Results of this study clearly indicate promising healing enhancing effects of using PRP-coated sutures at intestinal anastomotic site with little to no obvious disadvantages.

A contemporary view of platelet-rich plasma therapies: moving toward refined clinical protocols and precise indications

The positive extensive clinical experience with platelet-rich plasma (PRP) in different medical areas has prompted researchers to explore clinical opportunities for optimized PRP therapies. PRP is safe but we have to make it more effective. The growing diversity of formulations and presentations enrich the field of PRP research and offer hope to refine clinical indications. Moving toward targeting the right disease phenotypes with the right PRP formulation or combination product (PRP + cell products) can offer opportunities to change treatment options in osteoarthritis and nonhealing wounds. Both are active areas of research that could offer opportunities, although cost efficacy is still an open question. Our position is to believe that these serious disease areas are likely to benefit from PRP therapies.