Homologous Platelet-rich Plasma Research Articles

Platelet-rich plasma for the treatment of scleroderma-associated ulcers: a single-center experience and literature review

Systemic sclerosis (SS) is a complex connective tissue disease characterized by vasculopathy and progressive fibrosis, primarily considered an autoimmune disorder. SS can affect multiple organs and tissues, including the skin, respiratory, gastrointestinal, genitourinary, cardiovascular, and musculoskeletal systems. Skin involvement is common, and SS-related ulcers, especially digital ulcers, occur in roughly 50% of patients. These ulcers not only cause pain but also significantly impact patients' quality of life, and in severe cases, they can lead to infection, gangrene, and amputation. The search for novel therapies for scleroderma-related ulcers remains an ongoing research area. Platelet-rich plasma (PRP) has been investigated as a potential treatment for difficult-to-heal ulcers, including diabetic, pressure, and vascular ulcers. In this study, we share our experience in treating scleroderma ulcers with PRP. Ten patients with confirmed SS and chronic skin ulcers lasting at least six weeks, which had not responded to conventional treatments, were selected for the study. Homologous PRP gel was prepared and applied once a week for up to eight weeks. The ulcers were documented photographically before and after PRP treatment, and pain levels were assessed using a visual analog scale (VAS). We also conducted a systematic review of the literature focusing on the use of PRP in the setting of SS. The results from our casuistry showed that the ten patients, including eight females and two males with a median age of 52.5 years, had ulcer sizes ranging from 0.78 cm2 to 28.26 cm2. The ulcers were located on fingers, legs, and heels, and they were associated with various forms of SS, including limited and diffuse cutaneous involvement. Raynaud's phenomenon was prevalent, and two patients exhibited organ involvement. The average ulcer size at the end of PRP treatment decreased significantly, with a 78% reduction in ulcered area. Pain levels also markedly improved, as indicated by a reduction in VAS scores. With regards to systematic revision of literature, we retrieved 45 cases of SS treated with PRP-based therapeutic regimes. However, only a minority of them (n=16) underwent PRP treatment for the treatment of SS-related ulcers. An improvement in wound size and pain has been documented in all cases. Taken together, these data highlight the potential benefits of using homologous PRP in the treatment of scleroderma ulcers, emphasizing its positive impact on ulcer size reduction and pain relief.

Osteocalcin levels evaluation of freeze-dried homologus platelet-rich plasma in periodontal treatment

Objective: The aim of this study was to evaluate enhanced osteocalcin levels by using freeze-dried homologous platelet-rich plasma (FD HPRP) in periodontal treatment to support the osteogenesis process.
 Material and Methods: FD HPRP was made by HPRP from the blood bank, then freeze-drying and for sterilization, the γ-radiation process was carried out with doses of 20 and 25 kGy. The osteoblast (Cell line MG63) was cultured to confluent and then treated with FD HPRP 20 kGy, FD HPRP 25 kGy. Osteocalcin levels were tested using enzyme-linked immunosorbent assay (ELISA) on the 7th and 14th days. The data were analyzed using a t test
 Results: There was a significant difference in the osteocalcin levels between FD HPRP 20 and FD HPRP 25 (p<0.05). Osteocalcin levels increased on day 14 in each group and the highest one on the 7th and 14th days was FD HPRP 25.
 Conclusion: The present results showed that FD HPRP with simple preparation could support the osteogenesis process

Engineering homologous platelet-rich plasma, platelet-rich plasma-derived exosomes, and mesenchymal stem cell-derived exosomes-based dual-crosslinked hydrogels as bioactive diabetic wound dressings

The management of diabetic wounds remains a critical therapeutic challenge. Platelet-rich plasma (PRP) gel, PRP-derived exosomes (PRP-Exos), and mesenchymal stem cell-derived exosomes (MSC-Exos) have demonstrated therapeutic potential in wound treatment. Unfortunately, their poor mechanical properties, the short half-lives of growth factors (GFs), and the burst release of GFs and exosomes have limited their clinical applications. Furthermore, proteases in diabetic wounds degrade GFs, which hampers wound repair. Silk fibroin is an enzyme-immobilization biomaterial that could protect GFs from proteases. Herein, we developed novel dual-crosslinked hydrogels based on silk protein (SP) (sericin and fibroin), including SP@PRP, SP@MSC-Exos, and SP@PRP-Exos, to promote diabetic wound healing synergistically. SP@PRP was prepared from PRP and SP using calcium gluconate/thrombin as agonist, while SP@PRP-Exos and SP@MSC-Exos were derived from exosomes and SP with genipin as crosslinker. SP provided improved mechanical properties and enabled the sustained release of GFs and exosomes, thereby overcoming the limitations of PRP and exosomes in wound healing. The dual-crosslinked hydrogels displayed shear-induced thinning, self-healing, and eradication of microbial biofilms in a bone-mimicking environment. In vivo, the dual-crosslinked hydrogels contributed to faster diabetic wound healing than PRP and SP by upregulating GFs expression, down-regulating matrix metalloproteinase-9 expression, and by promoting an anti-NETotic effect, angiogenesis, and re-epithelialization. Hence, these dual-crosslinked hydrogels have the potential to be translated into a new generation of diabetic wound dressings.

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.

Comparison of topical 0.03% tacrolimus and homologous injectable platelet-rich plasma in the treatment of keratoconjunctivitis sicca in dogs.

Keratoconjunctivitis sicca (KCS) is predominantly an immune-mediated chronic inflammatory ocular disease that is commonly diagnosed in dogs. This study aimed to compare the conventional use of topical immunosuppressant tacrolimus 0.03% eye drops and a new therapy injectable homologous platelet-rich plasma (HPRP) into the third eyelid gland and inferior and superior palpebral conjunctiva of dogs with KCS. A total of 66 eyes from 33 dogs were evaluated. The eyes were divided into three equal groups: Negative control group, tacrolimus group (TG), and homologous platelet-rich plasma group (HPRPG). The animals were evaluated using the Schirmer's tear test-1 (STT-1), osmolarity test (OT), strip meniscometry test (SMT), tear film break-up test (TBUT), fluorescein test, lissamine green test (LGT), and cytological and histopathological analyses. In TG, there was a significant increase (p < 0.05) in the STT-1 and SMT values, and goblet cell count in the palpebral conjunctiva by the end of the study. In HPRPG, 36% (four dogs) received three applications, 55% (six dogs) received two applications, and 9% (one dog) received one application before the initial ocular signs improved. There was a significant decrease (p < 0.05) in the lymphocyte and neutrophil counts of the palpebral conjunctiva in HPRPG than in TG. Both groups showed equivalent improvements in TBUT, OT, and LGT values. Tacrolimus 0.03% eye drops were more efficient than HPRP in increasing tear production and the number of goblet cells. However, injectable HPRP was more efficient than tacrolimus in decreasing the number of conjunctival inflammatory cells. Treatment with injectable HPRP requires an average of two to three applications, is safe and feasible, and can be used as a cheaper alternative or as an adjuvant to conventional treatment with topical immunosuppressants.

​Evaluation of Homologous Platelet Rich Plasma (PRP) Drop and Leucocyte Platelet Rich Fibrin (L-PRF) Membrane for Corneal Ulcer Healing in Dogs

Background: To evaluate use of homologous platelet rich plasma (PRP) drop and leucocyte-platelet rich fibrin (L-PRF) clot/membrane as regenerative therapy for healing of corneal ulcer in dogs and its subsequent comparison with conventional therapy. Methods: In this randomized study, 30 dogs were divided into three groups of 10 animals each. It was ensured each group had grade I, II and III ulcers. Group I received medicinal treatment with antimicrobial and non-steroidal anti-inflammatory eye drop. In Group II PRP drops and in Group III L-PRF membrane was used to evaluate corneal ulcer healing. Homologous platelet concentrates were prepared in laboratory and used for assessment of healing on various grades of corneal ulcer on basis on reduction in size and depth of ulcer, presence of stromal infiltration, scleral involvement, corneal opacity and vascularization. Result: Post treatment, the size of corneal ulcer started to reduce gradually from day 7 onwards. Significant (p≤0.05) reduction was observed from day 10 in group I after instillation of drops Moxifloxacin and Flurbiprofen and in group II after instillation of PRP. It was measured as 5.35 ± 0.63 and 5.20 ± 0.98 mm at day 0, which reduced significantly (p≤0.05) to 3.90 ± 0.50 and 3.10 ± 0.98 mm at day 10 in group I and group II respectively. In group III there was significant reduction in size of ulcer from day 0 to day 7 measuring 7.80 ± 1.05 and 0.20 ± 0.11mm respectively. Thereafter, from day 10 onwards complete sealing of ulcer was observed in all the cases. Post treatment there was no significant reduction in corneal opacity from day 0 to day 30 in group I dogs and corneal opacity persisted specially in grade II and grade III ulcers. There was significant reduction (p≤0.05) in opacity from 2.90 ± 0.35 to 2.10 ± 0.38 and 3.00 ± 0.37 to 2.40 ± 0.34 in group II and group III dogs from day 0 to day 10 respectively. In group I, II and III there was significant (p≤0.05) reduction in vascularization from 1.50±0.30 to 1.20±0.13, 1.30±0.37 to 0.60±0.22 and 1.40±0.31 to 0.40±0.31 from day 0 to day 15 respectively. There was a significant reduction in vascularization on day 15 in group II and group III compared to group I animals.

​​The Effect of Platelet Rich Plasma on Wound Healing in the Repair of Experimental Penile Fractures

Background: Penile fractures are caused by the rupture of the tunica albuginea and the underlying layers of corpus cavernosum as a result of the exposure of the erect penis to blunt trauma. Although conservative treatment methods have been recommended in former studies, recent studies favor early surgical options. Platelet-rich plasma (PRP) is a blood product rich in cytokines and several growth factors, obtained from the patient’s own blood commonly used to stimulate healing in acute and chronic wound treatments. The efficiency of homologous PRP treatment in rats with penile fractures have been assessed in terms of clinical manifestation and histopathological findings in the present study. Methods: Thirty-five rats were randomly divided into five groups, each containing seven rats as follows: 1. Conservative group: Following the formation of penile fracture, medical interventions were not initiated on fracture area and the wound was left for secondary healing. 2. Bandage group: Following the formation of penile fracture, self-adherent elastic bandage (3M Coban) was applied to the fracture area for three days. 3. Primary repair group: Following the formation of a penile fracture, the lacerated area was repaired with 7/0 vicryl primary sutures. 4. Primary repair + Homologous Platelet Rich Plasma group: Before the operation, 10 cc of blood was taken from one rat under general anesthesia by intracardiac puncture and PRP material was prepared from this blood. Homologous PRP was topically administered on the wound in the fracture area and then the penile fracture was repaired with 7/0 vicryl as simple separate stitches. 5. Non-operative control group: Surgical procedures were not applied to this group; it was used as the control group. Result: The effect of the PRP treatments on the surgical repair options in the rats with penile fractures was investigated. The present findings revealed that following the repair with conservative treatments, the fracture format persisted and various complications like infection, oedema, excessive fibrosis and hyperemia were encountered. On the other hand, the best healing was achieved in primary repair + PRP group in terms of clinical manifestation and histopathological findings.

Clinical Studies on Platelet-Rich Plasma Therapy for Chronic Cutaneous Ulcers: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Significance: Platelet-rich plasma (PRP) may be a potential drug for treatment of chronic refractory ulcers, which increase the risk of systemic infection and local canceration. However, the efficacy and safety of clinical application of PRP are still controversial. Thus, this study was aimed to assess the efficacy and safety of PRP in patients with chronic ulcers. Recent Advances: For this meta-analysis, Cochrane's Library, MEDLINE, EMBASE, PubMed, Web of Science, and CINAHL (Cumulate Index to Nursing and Allied Health Literature) databases were searched. Results were pooled using a random-effects model. The primary outcome was the proportion of completely healed chronic ulcers. Critical Issues: Seventeen randomized controlled trials were included. Compared with the control group, PRP significantly increased the fraction of healed ulcers (pooled risk ratio [RR] = 1.50; 95% confidence interval [CI] = 1.20 to 1.87; I2 = 47.8%). In autologous PRP (APRP) and homologous PRP (HPRP) subgroups, there were statistical differences between the control group versus treatment subgroup (pooled RR = 1.30, 95% CI = 1.10 to 1.54, I2 = 25.7%; pooled RR = 3.53, 95% CI = 1.94 to 6.43, I2 = 0.0%, respectively). In terms of percent of chronic ulcers area healed, there was a statistically significant difference between the PRP-treated group versus the control group (standard mean difference [SMD] = 1.37, 95% CI = 0.91 to 1.82, I2 = 22.1%). As for PRP safety, there existed a statistically significant difference between the APRP subgroup and the HPRP subgroup, respectively (pooled RR = 0.58; 95% CI = 0.35 to 0.98; I2 = 0.0%) and (pooled RR = 4.12; 95% CI = 1.55 to 10.96; I2 = 6.8%). Future Directions: Our findings shows that PRP may be a beneficial treatment of chronic skin ulcers and that APRP may be much safer than HPRP.

Use of platelet concentrate gel in second-intention wound healing: a case\xa0report

BackgroundWound healing is a complex and dynamic process. Healing of acute and chronic wounds can be impaired by patient factors (that is, comorbidities) and/or wound factors (that is, infection). Regenerative medicine products, such as autologous/homologous platelet-rich plasma gel, may speed up the healing process. Autologous/homologous platelet-rich plasma is an advanced wound therapy used for hard-to-heal acute and chronic wounds. The cytokines and growth factors contained in platelet-rich plasma play a crucial role in the healing process.Case presentationA 61-year-old Caucasian male patient, suffering from mental retardation following meningitis, with a transplanted kidney due to prior renal impairment, and under immunosuppressant therapy, was submitted to aneurysmectomy of his proximal left forearm arteriovenous fistula. A few days later, the patient came to our attention with substantial blood loss from the surgical site. The wound presented no signs of healing, and after fistula reparation and considering persistent infection of the surgical site (by methicillin-resistant Staphylococcus aureus), surgeons decided for second-intention healing. To favor healing, 10 mL homologous platelet concentrate gel was sequentially applied. After each application, wound was covered with nonadherent antiseptic dressing. After only seven applications of homologous platelet concentrate gel, wound completely recovered and no amputation was necessary.ConclusionsTopical application of homologous platelet-rich plasma gel in healing wound shows beneficial results in wound size reduction and induces granulation tissue formation. Platelet-rich plasma could be a safe and cost-effective treatment for managing the cutaneous wound healing process to shorten the recovery period and thereby improve patient quality of life.

In Vitro Osteogenic Potential of Freeze-Dried Homologous Platelet-Rich Plasma

Introduction: Platelet-rich plasma (PRP) is paid attention for regenerative therapy because it clinically improves neoangiogenesis and periodontal regeneration. PRP can be made in form of homologous PRP (HPRP) from healthy, screened, and habitual blood donors and freeze-dried to increase stored time of HPRP and maintain growth factors. The purpose of this study is to evaluate freeze-dried homologous platelet-rich plasma (FD HPRP) on osteogenesis. Material and Methods: HPRP was taken from the blood bank and then a freeze-drying and γ-radiation process was carried out with doses of 20 and 25 KGy, respectively, for the sterilization. Blood was collected as much as 10 mL and then centrifuged at 700 rpm for 3 minutes to produce injectable platelet-rich fibrin (iPRF) as a positive control. Cell line MG63 were cultured to confluent, and then treated with FD HPRP 20 kGy, FD HPRP 25 kGy, iPRF, and one group non treated as a negative control. Osteocytes were determined based on morphology after hematoxylin staining to see the differentiation process. The data were analyzed using one-way analysis of variance (ANOVA). Results: There was a significant difference in the number of osteocytes between FD HPRP and negative control (P < 0.05). The number of osteocytes FD HPRP 25 was higher than FD HPRP 20. Conclusion: The present results indicate that FD HPRP could support the bone regeneration and used without any preparation like fresh PRP.

Does Estradiol Level in Platelet-Rich Plasma Improve Efficacy of Androgenic Alopecia Treatment?

Although some studies in the literature report that autologous and homologous platelet-rich plasma (PRP) can be employed in the treatment of androgenic alopecia (AGA), no study, to the authors' knowledge, has examined the estrogen concentration of prepared PRP. The authors aimed to determine the presence of estrogen in PRP and to investigate the effect of estrogen concentration of PRP on AGA treatment. Between 2017 and 2018, 30 male patients with hair loss complaints were included in this prospective study. Autologous PRP was injected in patients in Group 1. Homologous PRP with high estrogen levels was injected in the patients in Group 2. PRP was injected in both groups 4 times at 0, 1, 3, and 6 months. The obtained photographs were evaluated and hair densities of each patient at controls were calculated. The mean estrogen level measured in PRP was statistically significantly higher in Group 2. In both groups, the increase in hair density was observed from the first month, but this increase was statistically significantly higher in all controls in Group 2. In Group 2, there was a statistically significant increase in the 1st and 3rd months compared with the previous control, but there was no difference between the 6th and 12th months and the 3rd month. Increased hair density is greater and earlier in the group receiving estrogen-rich PRP than in the group utilizing autologous PRP. The authors think that estrogen-rich PRP may be employed in the treatment of AGA in the presence of an appropriate donor.

Effects of homologous and heterologous rich platelets plasma, compared to poor platelets plasma, on cutaneous healing of rabbits.

Purpose:To evaluate and compare the effects of homologous and heterologous PRP (Platelet-Rich Plasma) on the quality and speed of skin wound healing, compared to Poor Platelet Plasma (PPP).Methods:Twenty-one male adult rabbits were used; two for preparing homologous PRP, with the rest of them separated randomly in three groups, according to the treatment received: PPP - control (n=5), homologous PRP (n=7), heterologous (n=7). Excisional skin wounds were made on the back of the animals, for the application of homologous and heterologous PPP and PRP. At the 14th post-operative day (POD), the animals were subjected to a new wound, and the treatments were inverted. The wounds were evaluated macroscopically and histologically.Results:A larger percentage of scar retraction was observed on the group treated with heterologous PRP, compared to homologous PRP, at the third POD, an increase of 25.03% (p=0.01). No other statistically significant differences among treatments were observed. Among every group, skin healing was efficient, without local adverse effects.Conclusions:Heterologous PRP contributed with more tissue retraction at the beginning of the wound healing process. After this, there were no differences on the wound healing skin process treated with PRP or PPP. However, our findings suggest the presence of others plasmatic factors, besides platelets, which could also contribute to the wound healing process, and thus, should be further investigated.

Differences in donor compatibility for fresh and freeze-dried homologous platelet rich plasma studied using crossmatch test

Platelet-rich plasma (PRP) rich in growth factors has evolved as an important therapy for periodontal tissue regeneration. A healthy blood donors obtained for homologous PRP (h-PRP). The Freeze-drying h-PRP sample provides an effective method to ensure a longer shelf-life. The h-PRP samples are subjected to crossmatch testing in clinics to prevent any immune response in recipients. The present study aimed to evaluate the differences in donor compatibility on crossmatch test results towards fresh and freeze-dried h-PRP (FD h-PRP). This was a laboratory experiment, h-PRP prepared according to the protocol of blood bank, and 40 recipients blood samples divided into two groups, fresh h-PRP (control group) and FD h-PRP. The crossmatch test was performed to evaluate h-PRP compatibilities by using the gel-test method. The data were analyzed using the chi-square test. The results of the study showed that the crossmatch test on FD h-PRP samples was 100 % compatible and could increase the compatibility results of the donor. the FD h-PRP was safe to become donors and clinical applications.

A New Treatment for the Reconstruction of the Medial Compartment of the Ankle: The Combined Use of Biological Materials

Fractures, especially if articular and periarticular, are frequently associated to functional and clinical disabling outcomes and chronic pain. In particular, the injuries with loss of bone, ligament, and/or tendon tissue in which the full recovery of the wound area is not obtained are the worst anatomical/pathological conditions to heal. In this study, three different biological materials were used as regenerative approaches to rebuild the medial malleolus fracture of the ankle in which loss of bone, ligament, and tendon tissue occur. In particular, the morselized human bone tissue was combined with the human dermis decellularized, both augmented with homologous platelet-rich plasma. The magnetic resonance imaging study with contrast at the follow-up showed a signal compatible with vascularization of the tissue without sign of degeneration. Our new regenerative approach in which different biological materials were combined together showed a good choice of treatment for the reconstruction of not repairable outcome of a fracture.

Evaluation of autologous and homologous platelet rich plasma as a surgical wound healing promoter in rabbits

The present study compared the efficacy of autologous and homologous platelet rich plasma (PRP) as a surgical wound healing promoter in rabbits. Sixteen adult healthy rabbits were divided into two groups i.e. A and B. Group A was treated with autologous platelet rich plasma (APRP) and group B was treated with homologous platelet rich plasma (HPRP). Both groups were operated for skin grafting (auto grafting) at two (PRP treated experimental and control) sites. Clinical evaluation of PRP was performed by using macroscopic (edema, exudation, coloration, temperature, cosmetic appearance and healing status) and microscopic (acute inflammation, fibroblast proliferation and granulation tissue proliferation) parameters. The healing status, coloration and cosmetic appearance of APRP treated group were more satisfactory than HPRP treated group. APRP group also showed less inflammation, edema and more granular tissue proliferation as compare to HPRP group. It was concluded that autologous PRP is an efficient surgical wound healing promoter in rabbits.

Efficacy of Homologous, Platelet-rich Plasma Dressing in Chronic Non-healing Ulcers: An Observational Study.

BackgroundChronic non-healing ulcers are a frequent problem in developing countries and represent a heavy burden to the patients because they lack the necessary growth factors (GFs) to maintain the healing process and are frequently complicated by super, added infections. Traditional therapies, such as regular dressings and wound debridement, cannot provide satisfactory results since these treatments are not able to provide the necessary GFs. Platelet-rich plasma (PRP) helps in enhancing the wound healing by releasing various GFs. The aim was to evaluate the efficacy of PRP dressing in the treatment of chronic non-healing ulcers.MethodsPatients attending the outpatient department on a regular basis and those admitted as inpatients for chronic wound management were included in the study. It was an observational study done in a tertiary health center for a period of one year. All patients with eligible criteria were treated with PRP at twice-weekly intervals for a maximum of 10 dressings. At the end of the five weeks period, the reduction in the size of the ulcers (area and volume) was assessed.ResultsA total of 104 cases with chronic non-healing ulcers of various causes were treated with homologous PRP twice weekly for a maximum of 10 dressings. In those 104 patients, non-healing ulcers in 85 patients (81.73%) were healed at the end of the last dressing. Non-healing ulcers in 13 patients (12.5%) were healed with skin grafting. Among those patients, the baseline mean ulcer area was 5.03 cm2. For each visit, there was a reduction in the ulcer area. At the end of the last visit, the mean ulcer area was 1.69 cm2, which was significant in this study.ConclusionDue to the lack of necessary GFs in chronic non-healing ulcers, PRP is safe and enhances the healing rates of chronic wounds, thereby reducing overall hospital stay and morbidity.

Treatment of Tendon, Muscle and Ligament Injuries and Degenerative Joint Disorders with Homologous Platelet Rich Plasma Injection

Background: Recently, PRP are being used to treat acute and chronic injuries in an attempt to jump start healing due to being too much growth factor source. However, the homologous platelet rich plasma has been investigated in several studies to treat chronic wounds. In this study, we used H-PRP injection for tendon, muscle and ligament injuries and degenerative joint disorders. Our objective was to use homologous PRP for the treatment of tendon, muscle and ligament injuries and degenerative joint disorders and investigate the effects of it. Methods: We applied 164 injection of homolog PRP to 109 patients. We repeated the injection in 17 patients. The 139 injection were made intra-articulacy patients and 25 injections were applied to the soft tissue. We followed all of the patients for one year. Results: No severe adverse events or complications related to the injections were observed during the treatment or follow-up period. All of the patients were very satisfied with the treatment and had reported pain relief and increase of their life standards subjectively. Second session was performed to the seventeen patients after six months. Sixteen of them had resumed knee pain and one of them had temporomandibular joint pain. However, we also observed no side effects with patient satisfaction. Conclusion: This study showed Homologous PRP could be safely used without any adverse effects to treat the patients of tendon, muscle and ligament injuries and degenerative joint disorders with high patient satisfaction.

Evaluation of Three Methods of Platelet-Rich Plasma for Treatment of Equine Distal Limb Skin Wounds

Wounds localized on the distal limbs in horses are difficulty healing. No studies have been conducted to evaluate homologous platelet-rich plasma (PRP) in horses. The aim of this study was to evaluate the effect upon applying autologous PRP, homologous PRP, and autologous PRP gel on the wound healing process of wounds on the distal limb of horses. To study a possible correlation between the platelet count and wound healing time, four skin wounds of 4 cm2 were surgically created on the dorsolateral aspect of the third metacarpus in eight healthy adult horses. Each skin wound was randomly treated according to the established treatment groups (G): GI, treated with autologous PRP injection on the wound edges; GII treated topically with autologous PRP gel; and GIII homologous PRP injection on the wound edges and control group treated with saline solution injected on the wound edges. The animals were monitored every fifteen days throughout the wound healing process. The wound size was determined using a tape measure. Skin biopsies were obtained on the 15th and 30th day after the first PRP treatment. Autologous PRP gel treatment reduced the healing time in 15 days compared to the wounds of the control group. Histologically, GII presented a higher frequency of mild inflammation and mild to moderate neovascularization of biopsies 1 and 2. Platelet-rich plasma in gel form showed the best result on wound healing of the distal limb of horses in both clinical and histopathological evaluations. The homologous PRP is recommended for the recovery of animals with compromised hemodynamic conditions.

Eccentric Training for Tendon Healing After Acute Lesion: A Rat Model

Background: The tendon is a dynamic entity that remodels permanently. Platelet-rich plasma (PRP) injection has been shown to have a beneficial effect on tendon healing after lesion in rats. Furthermore, eccentric exercise seems to improve the mechanical quality of the tendon. Hypothesis: A combination of PRP injection and eccentric training might be more effective than either treatment alone. Study Design: Controlled laboratory study. Methods: Adult male rats were anesthetized, an incision was performed in the middle of their left patellar tendon and an injection of physiological fluid (PF) or homologous PRP was randomly made at the lesion level. The rats were then divided into 2 groups: the eccentric group, undergoing eccentric training 3 times a week, and the untrained group, without any training. Thus, 4 groups were compared. After 5 weeks, the tendons were removed and their ultimate tensile strength and energy were measured. Tendons were frozen for proteomic analyses when all biomechanical tests were completed. Statistical analysis was performed with linear mixed effect models. Results: No significant difference was found between the treatments using PF injection or PRP injection alone. However, the value of the ultimate tensile force at rupture was increased by 4.5 N (108% of control, P = .006) when eccentric training was performed. An intragroup analysis revealed that eccentric training significantly improved the ultimate force values for the PRP group. Proteomic analysis revealed that eccentric training led to an increase in abundance of several cytoskeletal proteins in the PF group, while a decrease in abundance of enzymes of the glycolytic pathway occurred in the PRP-treated groups, indicating that this treatment might redirect the exercise-driven metabolic plasticity of the tendon. Conclusion: Eccentric training altered the metabolic plasticity of tendon and led to an improvement of injured tendon resistance regardless of the treatment injected (PF or PRP). Clinical Relevance: This study demonstrates the necessity of eccentric rehabilitation and training in cases of tendon lesion regardless of the treatment carried out.

Homologous platelet-rich plasma for the treatment of knee osteoarthritis in selected elderly patients: an open-label, uncontrolled, pilot study.

The objective of this study was to evaluate the safety and the effect of platelet-rich plasma (PRP) intra-articular injections obtained from blood donors (homologous PRP) on elderly patients with early or moderate knee osteoarthritis (OA) who are not candidates for autologous PRP treatment. A total of 60 symptomatic patients, aged 65-86 years, affected by hematologic disorders and early or moderate knee OA, were treated with 5 ml of homologous PRP intra-articular injections every 14 days for a total of three injections. Clinical evaluations before the treatment, and after 2 and 6 months were performed by International Knee Documentation Committee (IKDC), Knee injury and Osteoarthritis Outcome Score (KOOS) and Equal Visual Analogue Scale (EQ VAS) scores. Adverse events and patient satisfaction were recorded. No severe complications were noted during the treatment and the follow-up period. A statistically significant improvement from basal evaluation to the 2-month follow-up visit was observed, whereas a statistically significant worsening from the 2-month to the 6-month follow-up visit was showed. The overall worst results were observed in patients aged 80 years or over and in those affected by minor bone attrition. It was found that 90% of patients were satisfied at the 6-month evaluation. Homologous PRP has an excellent safety profile but offers only a short-term clinical improvement in selected elderly patients with knee OA who are not candidates for autologous PRP treatment. Increasing age and developing degeneration result in a decreased potential for homologous PRP injection therapy. Further studies are needed to confirm these findings.