Effect of locally injected autologous platelet-rich plasma on second intention wound healing of acute full-thickness skin defects in dogs

Clinical observation of ultraviolet therapy combined with autologous platelet-rich plasma in the treatment of chronic refractory wounds

Refractory wounds present complex and serious clinical dilemmas in plastic and reconstructive surgeries. Currently, there are no standard guidelines for the treatment of refractory wounds. To observe the clinical effects of ultraviolet (UV) therapy combined with autologous platelet-rich plasma (PRP) on chronic refractory wounds. Between January 2021 and December 2022, 60 inpatients with chronic refractory wounds were enrolled. Twenty patients were assigned to each of control groups 1 and 2 and treatment group according to whether they received PRP or UV treatment. All the patients underwent thorough debridement. Control group 2 received UV radiation. The treatment group underwent UV radiation combined with PRP gel covering the wound. Control group 1 underwent routine dressing changes after surgery, followed by skin grafting or skin key transfer if needed. One month later, we observed the wound healing in the two groups. After 2-4 PRP gel treatments, the wounds of patients in the treatment group healed. The healing time was 25.25 ± 4.93 days, and the dressings were changed 4.15 ± 3.30 times, both of which were better outcomes than in both control groups. In the treatment group, epidermal growth factor (EGF), insulin-like growth factor (IGF), platelet-derived growth factor (PGF), and transforming growth factor β (TGF-β) were slightly higher, and the concentration of vascular endothelial growth factor (VEGF) was significantly higher than in the control group (p < 0.05). PRP combined with UV therapy significantly increased the concentration of wound growth factors, accelerated wound healing, shortened treatment time, reduced treatment costs, and alleviated pain in patients.

Therapeutic applications of canine platelets and their derivatives: a narrative review

Platelets contain a multitude of growth factors and play a crucial role in physiological processes such as thrombogenesis, tissue repair, and angiogenesis. As a result, platelet-derived products have significant potential for efficient utilization in the realm of regenerative medicine due to their therapeutic and biological attributes. Numerous studies have already substantiated the therapeutic viability of platelets in various canine ailments. The existing literature indicates a substantial surge in the clinical application of canine platelets, positioning platelet-derived products as a viable alternative to conventional therapeutic agents. Platelet concentrates, including platelet-rich plasma and platelet-rich fibrin are commonly used as a therapeutic modality in clinical cases. These therapeutic derivatives exhibit effectiveness in tissue regeneration and can serve as complementary therapies. Notably, they offer a cost-effective and easily accessible therapeutic option, which has demonstrated its benefits in chronic inflammatory disorders such as osteoarthritis and tendinitis, ophthalmic conditions, wound healing, and mandibular injuries in canine patients. The broad spectrum of therapeutic effects displayed by platelets is providing researchers with novel perspectives for crafting therapeutic models in future investigations. This review centers on exploring the therapeutic potential of canine platelets across diverse disorders. Further exploration into platelet products, encompassing their preparation and applicability in canine medicine, is imperative. These inquiries hold the promise of unveiling fresh horizons for the domain of regenerative medicine.

Evaluation of the Effectiveness of Medical-Grade Honey and Hypericum Perforatum Ointment on Second-Intention Healing of Full-Thickness Skin Wounds in Cats

This study aimed to determine the effects of two topical treatments on second-intention wound healing in cats. Eight 2 × 2 cm full-thickness wounds were created, four on each side of the dorsal midline of eight laboratory cats, to receive either medical-grade honey ointment (MGH) and its control (HC), or Hypericum-based ointment (HP) and its control (HPC). MGH or HP ointment was applied to four wounds on the same side, while the remaining four were used as controls, chosen at random. Planimetry, laser Doppler flowmetry, daily physical examinations, and histologic examinations on days 0, 7, 14, and 25 were used to assess the healing of wounds. Tissue perfusion was better in the MGH-treated (2.14 ± 0.18 mm/s) and HP-treated wounds (2.02 ± 0.13 mm/s) than in the untreated controls HC (1.59 ± 0.11 mm/s) and HPC (1.60 ± 0.05 mm/s), respectively (p = 0.001). Histopathology revealed that the median edema score was lower in the MGH-treated (2; range 1-4) compared to the HC-treated wounds (3; range 2-4) on day 7 (p < 0.05). The median angiogenesis score was higher on day 7 in the MGH-treated (2; range 1-3) compared to the HP-treated wounds (2; range 1-2) (p = 0.046). The fibroblast concentration was increased in the MGH-treated wounds (3.5; range 3-4) compared to the HP-treated wounds (3; range 2-4) on day 25 (p = 0.046). MGH and HP increased tissue perfusion compared to the untreated controls. The MGH-treated wounds had histologic parameters superior to the HP-treated wounds regarding angiogenesis and fibroblast concentration in cutaneous wound healing in cats. Topical application of MGH and HP did not accelerate the healing process of feline cutaneous wounds.

The usefulness of platelet-rich plasma to manage skin wounds: A meta-analysis

A meta-analysis investigation to measure the usefulness of platelet-rich plasma (PRP) to manage skin wounds (SWs). A comprehensive literature inspection till February 2023 was applied and 1349 interrelated investigations were reviewed. The 22 chosen investigations enclosed animals' SWs were in the chosen investigations' starting point, 3348 of them were treated with PRP, and 2259 were control. Odds ratio (OR) in addition to 95% confidence intervals (CIs) were used to compute the value of the usefulness of PRP to manage SWs by the dichotomous and continuous approaches and a fixed or random model. PRP significantly higher percent of decreases in open wound area (OWA) (MD, 10.07; 95% CI, 6.55-13.59, P < 0.001), and lower healing time (HT) (MD, -6.31; 95% CI, -10.69 to -1.93, P = 0.005) compared to control in animals' SWs. PRP had a significantly higher percent of decreases in OWA and lower HT compared to control in animals' SWs. However, caused of the small sample sizes of several chosen investigations for this meta-analysis, care must be exercised when dealing with its values.

Acellular bovine pericardium as a biological dressing for treatment of cutaneous wounds of the distal limb in donkeys (Equus Asinus)

This research was performed to determine the impact of repeated topical dressing with acellular bovine pericardium (ABP) on healing distal limb wounds in donkeys. Twelve male clinically healthy donkeys were subjected to general anesthesia, and full-thickness wounds of six cm2 (2 × 3 cm) were created on the middle dorsolateral surface of the metacarpi. Two defects were made on each donkey’s forelimbs; the right limb was considered a control wound, and the left one was considered a treated wound. Moreover, the control wounds were irrigated with saline every three days postoperatively and bandaged with a standard dressing. The treated wounds were covered with ABP dressings. The ABP dressing was reapplied thrice at 7-, 14- and 21-days post-wound induction. In addition, the wound healing process was monitored clinically, histopathologically, and immunohistochemically of tissue as growth factor-β1, epidermal growth factor receptor, and vascular endothelial growth factor. Besides, the gene expression profile of angiogenic and myofibroblastic genes was applied as vascular endothelial growth factor-A, collagen type 3α1, fibroblast growth factor 7, and the transforming growth factor-β1.

The results revealed that the wounds treated with ABP healed more quickly than the control wounds. Additionally, the mean days required for healing were significantly shorter in the ABP-treated wounds (p < 0.05; 69.5 ± 1.6) compared to control wounds (86.3 ± 3). Furthermore, immunohistochemical and gene expression analyses were significantly improved in ABP wounds than in control wounds. In conclusion, ABP is considered a natural biomaterial and promotes the healing of distal limb wounds in donkeys if applied weekly during the first three-week post-wound induction.

Platelet-rich plasma: a comparative and economical therapy for wound healing and tissue regeneration

Rise in the incidences of chronic degenerative diseases with aging makes wound care a socio-economic burden and unceasingly necessitates a novel, economical, and efficient wound healing treatment. Platelets have a crucial role in hemostasis and thrombosis by modulating distinct mechanistic phases of wound healing, such as promoting and stabilizing the clot. Platelet-rich plasma (PRP) contains a high concentration of platelets than naïve plasma and has an autologous origin with no immunogenic adverse reactions. As a consequence, PRP has gained significant attention as a therapeutic to augment the healing process. Since the past few decades, a robust volume of research and clinical trials have been performed to exploit extensive role of PRP in wound healing/tissue regeneration. Despite these rigorous studies and their application in diversified medical fields, efficacy of PRP-based therapies is continuously questioned owing to the paucity of large samplesizes, controlled clinical trials, and standard protocols. This review systematically delineates the process of wound healing and involvement of platelets in tissue repair mechanisms. Additionally, emphasis is laid on PRP, its preparation methods, handling, classification,application in wound healing, and PRP as regenerative therapeutics combined with biomaterials and mesenchymal stem cells (MSCs).

Locally Injected Autologous Platelet-Rich Plasma Improves Cutaneous Wound Healing in Cats

Cutaneous defects in cats are commonly encountered in clinical practice, and healing can be accomplished by first or second intention. Platelet-rich plasma (PRP) is characterized by a plasma concentration containing a large number of platelets in a small volume of plasma. The objective of the present study was to record the efficacy of PRP infiltration in open wounds in laboratory cats. Six wounds were created in the dorsal midline of eight laboratory cats, with the wounds of one side designated as the PRP group and the wounds of the other side as the control group. Wound healing was evaluated by daily clinical examination, planimetry, laser Doppler flowmetry, and histologic examination on days 0, 7, 14, and 25, and by measurement of metalloproteinases (MMPs)-2 and -9 and tissue inhibitor metalloproteinase (TIMP)-1 on days 0, 14, and 25. Based on the results of the present study, the mean time for full coverage with granulation tissue was shorter in the PRP group, the mean contraction and total wound healing percentage were increased compared to the control group, and finally, the perfusion measured with laser Doppler flowmetry was higher in the PRP group during all examination days. In conclusion, this is the first study focusing on the topical application of PRP in the treatment of open wounds in laboratory cats, and our results are encouraging—showing a more rapid healing in the PRP group.

Co-administration of platelet-rich plasma and small intestinal submucosa is more beneficial than their individual use in promoting acute skin wound healing

Background

Acute skin wounds may compromise the skin barrier, posing a risk of infection. Small intestinal submucosa (SIS) is widely used to treat acute and chronic wounds. However, the efficacy of SIS to accelerate wound healing still needs to be improved to meet clinical demands. To tackle this problem, platelet-rich plasma (PRP) is used due to its potency to promote proliferation, migration and adhesion of target cells. In this study, we applied PRP and SIS to skin wounds to explore their effects on wound healing by evaluating re-epithelialization, collagen production, angiogenesis and the inflammatory response.

Methods

A 1 × 1-cm full-thickness skin defect was established in mice. Sixty mice were divided into four treatment groups: PRP + SIS, PRP, SIS and control. On days 3, 5, 7, 10 and 14 post-surgery, tissue specimens were harvested. Haematoxylin and eosin, Masson's trichrome, immunohistochemical and immunofluorescence double staining were used to visualize epidermal thickness, collagen and vascular regeneration and inflammation.

Results

Wound contraction in the PRP and PRP + SIS groups was significantly greater, compared with the other groups, on days 3 and 5 post-surgery. A histological analysis showed higher collagen expression in the PRP and PRP + SIS groups on day 7, which was associated with a thicker epidermal layer on day 14. In addition, immunohistochemical staining showed that CD31-positive blood vessels and vascular endothelial growth factor expression in the PRP + SIS and PRP groups were significantly higher, compared with the control group. Furthermore, immunofluorescence double staining showed that the number of M1 and M2 macrophages in the PRP + SIS and PRP groups was higher, compared with the control and SIS groups alone, on day 3. However, on day 7, the number of M1 macrophages dramatically decreased in the PRP + SIS and PRP groups. The ratio of M2 to M1 macrophages in the PRP + SIS and PRP groups was 3.97 and 2.93 times that of the control group and 4.56 and 3.37 times that of the SIS group, respectively.

Conclusion

Co-administration of SIS and PRP has a better effect on promoting angiogenesis, re-epithelialization and collagen regeneration in managing acute wound healing than either agent alone.

Case Report: A Novel Ventilated Thermoplastic Mesh Bandage for Post-operative Management of Large Soft Tissue Defects: A Case Series of Three Dogs Treated With Autologous Platelet Concentrates

A ventilated thermoplastic mesh bandage was used for the post-operative management of large soft tissue defects in three dogs. Once the granulation tissue appeared, the wounds were treated with liquid or jellified autologous platelet concentrates, Platelet Rich Plasma (PRP) and Platelet Lysate (PL), to improve the wound healing process. After cleaning the wound with sterile physiological solution, a dressing was performed with several layers of cotton. A window through the layers of cotton was opened above the wound. Then, the platelet concentrate was topically applied, and the bandage was completed by placing, over the access window, a ventilated thermoplastic mesh modeled according to the size and shape of the wound. After 24 h, it was replaced by a low adhesion bandage. The thermoplastic mesh avoids the direct contact between the wound and the external layers of the bandage, preventing the drainage of the topical agent and the removal of the growing healthy granulation tissue. The bandage proposed in this study is easily applied by the veterinarian and well-tolerated by the animal, ensuring high welfare standards in stressed patients presenting compromised clinical conditions.

Use of Autologous Leucocyte- and Platelet-Rich Plasma (L-PRP) in the Treatment of Aural Hematoma in Dogs

Leukocyte- and platelet-rich plasma (L-PRP) can accelerate the healing process by providing increased concentrations of platelet-derived growth factors. The objective of this study was to evaluate the clinical effect of L-PRP in the treatment of canine aural hematomas associated with otitis externa. Twenty mL of citrated whole blood was collected from each of the 17 dogs included and autologous L-PRP was produced. The aural hematoma was drained and 0.5–1 mL of L-PRP was injected. The dogs were examined weekly until 7 days after complete clinical healing. A final clinical follow-up was performed 6 weeks after the first treatment with L-PRP. If there was recurrence of the aural hematoma at the first follow-up, the treatment was repeated. In total, 2/17 cases were lost after the first follow-up. In 5/17 dogs, a short-term recurrence occurred. In 12/15 cases, complete clinical resolution was achieved with a single L-PRP application (Group A1) and in 3/15 with two treatments (Group A2). The mean time to complete clinical resolution was 16 ± 8.7 days (A1) and 23.3 ± 4 days (A2), respectively. No side effects were reported. The in situ administration of autologous L-PRP resulted in a complete resolution of the aural hematoma in all dogs that completed the clinical trial.

Effectiveness of Pre PRP Injection and Post Elevation Flap at Extended Random Flap Rat Skin

Background:Closure of the defect with a random skin flap is constrained by the extent of the defect area. Several studies have shown the benefits of administration of PRP (Platelet Rich Plasma) in random skin flap. The purpose of this study is to compare the effect of PRP injection given before flap elevation, after flap elevation and control on the extended random skin flap procedures in rats.Methods: This research is experimental with randomized post test only control group design (n = 27, divided into 3 treatment groups) that compare the effectiveness of PRP injection 24 hours prior to the elevation of the flap, after the elevation of the flap, and control in the extended random skin flap in rats. Random skin flap is made in the ratio 1: 5 on the rat skin. Measurement of viable area were observed on days 1, 7 and 14.Results: There were significantly increased viability of random skin flap on the group with PRP injection 24 hours prior flap elevation compared to other group of treatment. The average of viability on day first 39%±13% ;42%±34%; 62%±14%. On day 7th24%±13%; 36%±26%; 62%±12%.On day 14th16%±15%; 28%±22%; 60%±11%.Conclusion: Injection of PRP on extended random skin flap on rat 24 hours before flap elevationincrease viability of the flap compared to control group and group which receive PRP injection on extended random flap on rat skin after elevation of the flap. Viability increased due to angiogenesis stimulation after PRP injection.

The effect of deferoxamine injection on composite graft survival in rabbits

BACKGROUND

Composite graft as a reconstructive therapy option has limitations in size so that it is easily necrotic. Deferoxamine administration has been associated with increased neo-vascularity in wounds. We aimed to compare the administration of deferoxamine and Platelet-Rich Plasma (PRP) injection in a composite graft in rabbits.

METHODS

Thirty New Zealand rabbits were divided into three groups; the control group, the deferoxamine group, and the PRP group. The composite graft with a diameter of 2 cm was taken and replanted after rotating it 180°. The mean graft viability and the mean number of capillaries were evaluated on day 7 (POD 7) by macroscopic and histological evaluation using Hematoxylin-Eosin staining.

RESULTS

While the mean number of capillaries was not significantly different in control, deferoxamine, and PRP groups (p = 0.21), the mean survival rate in the control, deferoxamine, and PRP groups reached a significant level with p-value of 0.006 (66.6% vs. 63.8% vs. 99.6%, respectively).

CONCLUSIONS

Deferoxamine group had the highest number of capillaries, but had the lowest survival rate. In the PRP group, it had the lowest number of capillaries, but had the highest survival rate.

Autologous Platelet-Rich Plasma Enhances the Healing of Large Cutaneous Wounds in Dogs

Platelet-rich plasma (PRP) is known to play a crucial role in skin wound healing, in both Human and Veterinary Medicine. Remarkably, until now, no studies have reported PRP treatment in subacute full-thickness skin wounds of the dog. The aim of this study was to evaluate the effects of two consecutive applications of autologous PRP, with the second application after 15 days, in 6 dogs showing large subacute skin wounds. The percentage of contraction, re-epithelialization and healing in all treated patients indicated that no complications or side effects, associated with consecutive PRP treatments, occurred in any patient and all wounds achieved complete closure and re-epithelialization. Our results suggest a positive effect of repeated autologous topical PRP treatments in large cutaneous subacute wounds of different etiology. Therefore, this PRP treatment could represent a simple, cost-effective, and valid alternative to promote healing processes in subacute large wounds cases in dogs.

Efficacy of a Semi Automated Commercial Closed System for Autologous Leukocyte- and Platelet-Rich Plasma (l-prp) Production in Dogs: A Preliminary Study

BACKGROUND

To characterize the cellular composition (platelets, erythrocytes, and leukocytes) and determine platelet-derived growth factor isoform BB (PDGF-BB) concentration in canine leukocyte- and platelet rich plasma (L-PRP) produced using a commercial semi-automated closed system.

METHODS

Twenty milliliters of citrated whole blood were obtained from 30 healthy un-sedated canine blood donors and processed using a semi-automated completely closed commercial system (CPUNT 20, Eltek group, Casale Monferrato, Alessandria, Italy) according to the manufacturer's instructions. Erythrocyte, leukocyte, and platelet counts were determined in both whole blood (WB) and resultant L-PRP. The PDGF-BB concentration was evaluated after bovine thrombin activation of 10 L-PRP samples.

RESULTS

This commercial system produced on average 2.3 ± 0.7 mL of L-PRP containing a high concentration of platelets (767,633 ± 291,001 μL, p < 0.001), with a 4.4 fold increase in platelet count, lower concentration of erythrocytes (528,600 ± 222,773 μL, p < 0.001) and similar concentration of leukocytes (8422 ± 6346 μL, p = 0.9918) compared with WB. L-PRP had an average of 3442 ± 2061 pg/mL of PDGF-BB after thrombin activation. Neutrophils, lymphocytes and monocytes average percent content in L-PRP was 14.8 ± 13.2, 71.7 ± 18.5 and 10.7 ± 6.4, respectively.

CONCLUSION

Sterile canine L-PRP prepared using this semi-automated closed system is easy to obtain, produces a significant increase in platelet count compared to WB and contains a detectable concentration of PDGF-BB after activation. Additional in vitro and in vivo studies are needed to assess inflammatory markers concentration and the therapeutic efficacy of this L-PRP in dogs.

Treatment of canine osteoarthritis with allogeneic platelet-rich plasma: review of five cases

Background:

Osteoarthritis (OA) is a major cause of chronic pain and lameness in dogs. Platelet-rich plasma (PRP) is a concentrate of growth and differentiation factors from the blood, which can be used in regenerative medicine strategies.

Aim:

The main aim of this study was to evaluate the effect of allogeneic PRP on the treatment of canine OA.

Methods:

Five dogs from several breeds, between 6 and 12 years old, and from both genders were studied. Clinical and imageological examinations diagnosed OA in the knee, tibiotarsal, elbow, and intercarpal joints. These dogs were refractory to medical therapy and to physical rehabilitation protocols that included shockwave therapy, laser therapy, electrostimulation, hydrotherapy, and diathermy.

Animals were treated with allogeneic PRP obtained from the blood of the five dogs, which was processed in a pool. Echoguided intra-articular PRP injection was administered under sedation and after aseptic field preparation. Lameness at walk and trot (five grades) and pain (five scores) were evaluated before treatment and 30, 60, and 90 days post-treatment.

Results:

All animals presented improvements at 30 and 60 days in both parameters. Four dogs showed a decrease of three grades of lameness after 90 days and there was complete absence of lameness in 2 days. Pain was reduced from severe and moderate to mild in all the dogs after 30 days, and among them, three revealed no pain after 90 days.

Conclusion:

This study sheds light on the applicability and safety of a single administration of allogeneic PRP in osteoarthritic dogs.

Prospective Evaluation of Feline Sourced Platelet-Rich Plasma Using Centrifuge-Based Systems

Objective: To evaluate the hematologic components of platelet-rich plasma (PRP) generated using feline blood with two commercially available centrifuge-based systems^1,2.

Materials and methods: Twenty healthy adult cats were enrolled in this prospective study from November 2018 to January 2019. Feline blood samples were obtained for analysis of whole blood (WB) cellular components and preparation of PRP product. PRP was prepared using two commercial systems and complete blood count (CBC) testing was performed on both WB and PRP samples. The cellular composition of the PRP product was compared to the WB sample for each patient.

Results: Both systems showed significant decrease of median RBC concentration in PRP products compared to WB samples (P = 0.002 for both systems). System 1 significantly decreased median WBC concentration (P = 0.002). System 2 decreased WBC concentration, though statistical significance was not reached (P = 0.63). Median platelet concentration was decreased by 3% using System 1, and increased by 187% using System 2. Platelet aggregation presented a challenge with 8/20 (40%) of samples demonstrating platelet aggregation.

Clinical relevance: Commercial systems available for generation of PRP may be useful for creating a feline sourced product and in this study showed promise in decreasing RBC and WBC concentration. Neither system tested achieved 2–5 times platelet concentration from baseline. Platelet aggregation presented a significant obstacle to reliable generation of PRP products using feline blood. This treatment modality may be particularly beneficial for feline patients with osteoarthritis and soft tissue injuries, though first characterizing the PRP product made using feline blood is critical to validate its use in further clinical studies.

Platelet Function and Therapeutic Applications in Dogs: Current Status and Future Prospects

Significant progress has been made in the functional characterization of canine platelets in the last two decades. The role of canine platelets in hemostasis includes their adhesion to the subendothelium, activation, and aggregation, leading to primary clot formation at the site of injury. Studies on canine platelet function and advancements in laboratory testing have improved the diagnosis and understanding of platelet-related disorders as well as the knowledge of the mechanisms behind these diseases. This review focuses on the most recent discoveries in canine platelet structure, function, and disorders; and discusses the efficacy of various tests in the diagnosis of platelet-related disorders. With the relatively recent discovery of angiogenetic and reparative effects of growth factors found in platelets, this review also summarizes the use of canine platelet-rich plasma (PRP) alone or in association with stem cells in regenerative therapy. The characterization of proteomic and lipidomic profiles and development of platelet gene therapy in veterinary species are areas of future study with potential for major therapeutic benefits.

Leukocyte-rich PRP versus leukocyte-poor PRP - The role of monocyte/macrophage function in the healing cascade

The mechanism of action of Platelet Rich Plasma (PRP) is thought to be related to the biomolecules present in α-granules. However, for the healing process to occur, an inflammatory phase is also deemed necessary. Leukocytes present in the inflammatory phase release both pro- and anti-inflammatory molecules. The latter may play an important role in the process of "inflammatory regeneration". Thus, we propose that in the context of healing, both platelets and leukocytes play an important role, specifically due to the macrophage's plasticity to switch from the M1 to M2 fraction. Therefore, we propose that PRP products derived from the buffy coat may be more beneficial than detrimental from a standpoint of the regenerative potential of PRP.

A mini-pig model for evaluating the efficacy of autologous platelet patches on induced acute full thickness wound healing

Background

Autologous platelet concentrates are currently widely used across different areas of regenerative medicine in order to enhance the wound healing process. Although several protocols for platelet concentrates are available, their application remains difficult due to different protocols leading to distinct products with vary potential biological uses. In this study, we attempted to make a platelet patch (PP) using mixtures of platelet rich plasma (PRP) injection and platelet rich fibrin (PRF) to promote wound repair and regeneration.

Results

Experiments were performed using a full-thickness wound model in mini-pigs. Autologous PRP, PRF and PP were prepared immediately before creating four full-thickness skin wounds in pigs. We quantified concentrations of platelets, thrombin and various growth factors to ensure that the desired effect can be produced. After surgery, hydrocolloid dressing, PRP injection, PRF and PP was applied to experimentally induced wounds. Application efficacy was evaluated by measurement of wound sizes and histological examination. The results indicated that all wounds showed a significant size reduction. Wound repair efficacy in response to PP treatment exhibited enhanced re-epithelialization compared to PRP and PRF (P < 0.05) and higher wound contraction than did PRF application (P < 0.05). Another aspect, experiment using DsRed transgenic pigs as blood donors demonstrated that leucocytes in PP were incorporated into the wound bed at the end of the study, suggesting that leucocytes activity is stimulated in response to PP application. Safety of the experimental processes was also confirmed by examination of organ biopsies.

Conclusions

We used a mini-pig model to evaluate the efficacy of lab-made PP on induced full-thickness wound healing. Results demonstrated that application of one piece of PP was enough to obtain comparable efficacy versus general utilization of PRP or PRF for wound care. We also demonstrated that leucocytes in PP were incorporated into the wound bed and no safety concerns have been found in the whole experiment. This study provides a novel and feasible method for veterinary or clinical wound care.

Use of cancellous bone grafting to promote granulation tissue in a distal limb wound in a dog

A 5-year-old female spayed Shetland sheepdog presented for evaluation of bandage sores on the left pelvic limb after a splint was placed to stabilise a digit fracture incurred approximately 2 weeks previously. Multiple areas of necrosis were identified upon bandage removal. After debridement of devitalised tissue, a 4 cm wound on the plantar surface of the metatarsal bones (with exposed bone and tendons) remained. The Papineau technique (which involves removal of infected or necrotic tissue, placement of autogenous cancellous bone graft within a wound, and delayed skin closure) was used to treat this wound. Use of bone graft in this manner aims to promote early granulation tissue formation and reduce the time until wound reconstruction can be performed. Autogenous cancellous bone graft was harvested from the proximal humerus and placed within the metatarsal wound. Once a healthy granulation tissue bed was noted to cover the bone graft, a meshed full thickness skin graft was placed. To our knowledge, this is the first report of the Papineau technique being used for this purpose in a dog.

Platelet Rich Plasma: New Insights for Cutaneous Wound Healing Management

The overall increase of chronic degenerative diseases associated with ageing makes wound care a tremendous socioeconomic burden. Thus, there is a growing need to develop novel wound healing therapies to improve cutaneous wound healing. The use of regenerative therapies is becoming increasingly popular due to the low-invasive procedures needed to apply them. Platelet-rich plasma (PRP) is gaining interest due to its potential to stimulate and accelerate the wound healing process. The cytokines and growth factors forming PRP play a crucial role in the healing process. This article reviews the emerging field of skin wound regenerative therapies with particular emphasis on PRP and the role of growth factors in the wound healing process.

Platelet-rich plasma to treat experimentally-induced skin wounds in animals: A systematic review and meta-analysis

The objective of the study was to review current literature to determine whether the topical application of platelet-rich plasma (PRP) promotes healing in experimentally-induced full-thickness skin wounds in animals. The hypothesis was that the adjunct of PRP has a positive effect on wound healing. An electronic search was carried out on the following databases: Web of Science, Cochrane Library, PubMed, Research Gate, Cochrane Wounds Group, Veterinary Information Network. No publication date nor language restrictions were applied. Randomised and not randomised controlled clinical trials comparing PRP with placebo or with other treatments were included. The reduction of open wound area in PRP-treated (test) wounds compared to control wounds was the primary outcome. Secondary outcomes were healing time and number of healed cases in test group compared to control. The following effect sizes were calculated: the Hedges' g for continuous variables; the odds ratio for binary data. Eighteen controlled clinical trials were included in the qualitative and quantitative synthesis, with a total of 661 wounds. All studies were published in the period 2007-2016. Eight studies were carried out on rodent/lagomorph mammals and 10 on non-rodent/lagomorph mammals. In all included studies, control wounds underwent placebo or were left untreated. The PRP group showed a better healing performance than the control group in each outcome. The effect size was statistically significant considering the primary outcome and the overall aggregation of the three outcomes. The effect size, although in favour of the treatment with PRP, was not significant considering the healing time and the number of healings. The overall heterogeneity was mild or moderate. Five studies reported a high risk of selection bias. The publication bias was always mild or absent. The results support the hypothesis of the positive effects of the PRP when compared to control groups in the treatment of experimentally-induced full-thickness skin wounds in animals. PRP can therefore be considered an effective adjunctive therapy in stimulating second intention healing of acute wounds in healthy animals.

Low-level laser therapy: Case-control study in dogs with sterile pyogranulomatous pododermatitis

AIM

Low-level laser therapy (LLLT) is a therapeutic photobiostimulation with properties in reducing swelling, inflammation, and promoting tissue healing. The objective of this pilot study was to evaluate LLLT in sterile pyogranulomatous pododermatitis in five dogs.

MATERIALS AND METHODS

In each dog, one lesion was designated as the control (treated with a 0.0584% hydrocortisone aceponate spray), and one or more other lesions were treated with a gallium aluminum arsenide-laser, daily for 5 days. Lesions were scored before treatment (D0), at the end (D4), 16 days after the last laser treatment (D20), and after 2 months (D65).

RESULTS

Comparing the treated lesion group with the control lesion group, the clinical score was similar at D0, whereas there was a statistically significant difference at D4 and D20; in the treated group over time, there was a statistically significant improvement between D0, D4, and D20. Lesion recurrence was absent in more than 50% of the treated lesions at D65. No adverse reactions were reported.

CONCLUSION

Given the positive results of this first clinical study, it would be interesting to extend the study to confirm the validity of this type of therapy in sterile pyogranulomatous pododermatitis in the dog.

Effect of platelet-rich plasma on the healing of cutaneous defects exposed to acute to chronic wounds: a clinico-histopathologic study in rabbits

Background

Platelet-rich plasma (PRP) contains numerous growth factors to promote wound healing and angiogenesis. The aim of this study was to gain further information about the benefits of platelet-rich-plasma for healing cutaneous acute to chronic wounds.

Methods

A total of 30 New Zealand albino rabbits (n = 15/group) were randomly assigned to two experimental groups: control group, and PRP group. Bilateral resection defects measuring 3 cm were surgically created on the dorsolateral of the cutaneous in animals and the defects were randomly divided into two mentioned groups. Wound area, neovascularization, size and epithelialization were compared on days 7, 14 and 21 post-wounding. Histopathological analyses were conducted on 15 specimens from each group after sacrifice by the cellular aspects of the regeneration of the tissue.

Results

Our results were indicated that the wound area of PRP was smaller than that in the non-treated group on days 7, 14 and 21. Furthermore, a significant decrease of the wound size was observed in PRP groups that were significantly greater than that in the control group. A significant increase of the mean vascular density was noted in the PRP treated groups compared to the control groups at day 14 and especially day 21. This results indicated that PRP treated group’ enhanced angiogenesis at the wound beds as compared to no treatment group.

Conclusion

These results could be useful for researchers in the growing fields of tissue repair and experimental wound healing. Further studies will be essential to determine the role of PRP in clinical practice.