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

Evaluation of the Effects of Autologous Leukocyte- and Platelet-Rich Fibrin Membranes for Treating Chronic Wounds: A Prospective Study

(1) Background: The aim of this prospective study was to evaluate the efficacy of topical application of leukocyte- and platelet-rich fibrin (L-PRF) membranes for treating chronic cutaneous wounds in dogs. (2) Methods: Chronic wounds unresponsive to conventional treatments were assessed on digital photographs and classified using the Bates-Jensen Wound Assessment Tool (BWAT). Each lesion was treated with L-PRF membranes. Epithelialization, granulation tissue formation, wound healing rate, and contraction were statistically analyzed during follow-up. (3) Results: All but one of the cases were treated with a single application of L-PRF for a median of 30 days after onset. All wounds healed after a median of 22 days. The BWAT score, total wound area, and granulation tissue decreased significantly over time while wound contraction increased. The most significant reduction in the total wound area was observed within the first 3 weeks after treatment. None of the dogs required the administration of antibiotics. (4) Conclusions: L-PRF membrane promoted the wound healing process in dogs and is a valuable and cost-effective tool for treating chronic wounds, thereby reducing the need for antibiotics administration.

Comparing the Effectiveness of Platelet-Rich Plasma Alone Versus Combined With Microneedles or Radiofrequency for Neck Wrinkle Treatment

BACKGROUND

Neck wrinkles are a prominent characteristic of skin aging, with recent studies indicating that interventions such as platelet-rich plasma (PRP), microneedling (MN), and radiofrequency (RF) can effectively rejuvenate aging skin.

AIMS

This study aims to assess and compare the efficacy of three treatment modalities in addressing neck wrinkles.

METHODS

Fifteen female participants with a neck Lemperle Wrinkle Assessment Scale (WAS) score of 3-4 were enrolled in a randomized clinical trial. The subjects were randomly assigned to three treatment groups: PRP injection, MN + PRP topical PRP application, and RF + PRP injection. They received treatment once a month for three consecutive months, and a clinical outcome evaluation was performed at 1 and 6 months after the final treatment.

RESULTS

The WAS scores and global aesthetic improvement score (GAIS) demonstrated notable enhancements 1 month postfinal treatment across all three groups, with a notably greater number of participants experiencing improved outcomes in the RF + PRP group 6 months posttreatment. Specifically, at the 1-month follow-up, the RF + PRP group exhibited a statistically significant enhancement in skin elasticity and collagen, surpassing the improvements observed in the other two groups (p < 0.05). No significant disparities in skin elasticity and collagen were detected in all groups prior to and after 6 months of treatment. Adverse events were mild and transient, such as redness, swelling, bruising, and pain.

CONCLUSION

This study revealed that all the treatments can effectively improve neck wrinkles 1 month after the last treatment. A better therapeutic effect could be observed in the RF + PRP group compared with the other two groups at 6 months after the last treatment.

Antibacterial Effect of Canine Leucocyte Platelet-Rich Plasma (L-PRP) and Canine Platelet-Poor Plasma (PPP) Against Methicillin-Sensitive and Methicillin-Resistant Staphylococcus pseudintermedius

Staphylococcus pseudintermedius (SP) is a commensal and opportunistic pathogen of skin and mucosal surfaces, isolated from healthy dogs and from canine pyoderma cases. It has recently gained attention due to its increasing antibiotic resistance. Platelet-rich plasma (PRP) is a biological product, obtained through a blood centrifugation process, which has antibacterial properties evidenced by in vitro and in vivo studies conducted in both the human and veterinary field. This in vitro study evaluated the antimicrobial effect of canine non-activated and activated leucocyte-rich PRP (L-PRP) and platelet-poor plasma (PPP) against two strains of SP isolated from dogs with pyoderma: one a multidrug-resistant strain (MDR) and one a non-MDR strain. Twenty healthy un-sedated adult blood donor dogs were enrolled for L-PRP and PPP production via a closed semi-automatic system for veterinary use. The evaluation of antimicrobial effect was performed using the micro-inhibition in broth method, exposing SP strains to 10 L-PRP, 10 activated L-PRP and 10 PPP samples, respectively. Bacterial growth was evaluated using CFU count at three timepoints (immediately after incubation T0, after 1 h T1 and after 2 h T2). L-PRP and PPP had a significant antimicrobial effect at all three timepoints which was similar against both non-MDR and MDR SP strains. Activation appeared to reduce the duration of the antimicrobial effect in L-PRP. More studies are necessary to confirm these preliminary results.

Sea food by-products valorization for biomedical applications: evaluation of their wound regeneration capabilities in an Ex vivo skin model

Introduction

The skin is often exposed to harmful stimuli that might compromise its integrity and functionality. After an injury, the skin has a limited capability to restore its complex structure, and in the case of severe skin damage, surgical operations and rapid application of wound dressings are often required to promote optimal wound healing. Nowadays, collagen-based biomaterials are widely used in combination with bioactive molecules able to prevent excessive inflammation and possible infections. In line with a circular economy and blue biotechnology approach, it was recently demonstrated that both collagen and bioactive molecules (i.e., antioxidant compounds) can be sustainably obtained from sea food by-products and effectively used for biomaterial development. Herein, we describe and compare the application of two marine collagen-based wound dressings (CBWDs), produced with materials obtained from sea urchin food waste, for the treatment of skin lesions in a wound healing organ culture (WHOC) model.

Methods

The ex vivo WHOC model was set up starting from rat skin explants and the induced lesions were assigned into three different groups: control (CTRL) group, not treated, marine collagen wound dressing (MCWD) group, and antioxidants-enriched marine collagen wound dressing (A-MCWD) group. After 5 and 10 days, specimens were examined for organ maintenance and assessed for the healing process.

Results

Immunohistochemical results showed that both CBWDs were similarly successful in prolonging skin repair, preserving the epidermal barrier up to 5 days under static culture conditions. Histological and gene expression analysis highlighted that the A-MCWD might support and accelerate skin wound healing by exerting antioxidant activity and counteracting inflammation.

Discussion

Overall, these findings underline the potential of sea urchin food waste as a novel resource for the development of functional medical devices for the treatment of skin wounds.

Autologous platelet-rich fibrin enhances skin wound healing in a feline trauma model

Trauma is a common cause of cutaneous surgical disease with an increased risk of secondary infection in cat clinics. Platelet-rich fibrin (PRF), a platelet and leukocyte concentrate containing multiple cytokines and growth factors, is known to accelerate the healing of wounds. However, how PRF affects wound healing in the cat trauma model has not been fully investigated. The study aimed to examine the impact of PRF on skin wound healing in the cat trauma model. In this study, PRF from cats was successfully produced for our investigation. The models of feline trauma were effectively established. A total of 18 cats were randomly divided into 3 groups (n = 6): (1) Control group (CON); (2) PRF group; (3) Manuka honey group (MAN, as a positive control). Experiments were performed separately on days 7, 14, 21, and 28. Our results showed that PRF was a safe and efficient method of wound healing that did not influence the cat's body temperature, respiration rate, and heart rate (HR). PRF accelerated skin wound healing in the cat trauma model based on the rate and histological observation of wound healing. In addition, PRF promoted the production of growth factors and suppressed inflammation during wound healing. PRF accelerated wound healing by increasing the formation of collagen fibers, as shown by Masson-trichrome staining. The outcomes of the PRF and MAN groups were comparable. In conclusion, PRF improves the healing of skin wounds in cats by boosting the synthesis of growth factors, reducing inflammation, and enhancing the synthesis of collagen fibers.

The effect of two platelet-rich plasma aspiration techniques on plasma cellular concentrations using a double syringe gravitational centrifugation system

OBJECTIVE

To identify which aspiration technique increased plasma platelet concentration and which technique minimized plasma leukocyte and erythrocyte concentrations using a gravitational double-syringe platelet rich plasma (PRP) system.

STUDY DESIGN

Controlled laboratory study.

ANIMALS

Thirty adult dogs.

METHODS

Whole blood was collected into two autologous conditioned plasma (ACP) syringes and an ethylenediaminetetraacetic acid (EDTA tube) (control samples). The ACP syringes were centrifuged for 5 min at 1500 rpm. The proximal 2 mL of plasma from one ACP syringe was deposited in an EDTA tube (preflash samples). Plasma from the second ACP syringe was withdrawn until the buffy coat was pierced, producing a "flash" of red blood cells, agitated and deposited into an EDTA tube (flash samples). Complete blood counts were performed.

RESULTS

Mean plasma platelet concentrations of the control, preflash, and flash samples were 2.4 × 105/dL, 3.3 × 105/dL and 4.1 × 105/dL, respectively. The mean platelet concentration of the flash samples was 7.9 × 104/dL higher than the preflash samples (p = .005). The mean platelet concentration was lower in the control samples than the preflash (p = .002) and flash (p < .0001) samples. The median plasma leukocyte concentration of the preflash samples (0/dL) was lower than in the flash samples (2.4 × 103/dL) (p = .001). The median plasma hematocrit value of the preflash samples (0%) was lower than in the flash samples (1.0%) (p = .002).

CONCLUSION

The flash method is not necessary to produce a PRP sample.

CLINICAL SIGNIFICANCE

Both methods produced PRP. However, clinicians should avoid aspirating the buffy coat when processing PRP for therapies where leukocytes and erythrocytes are contraindicated.

Advances and prospects of platelet-rich plasma therapy in veterinary ophthalmology

In the recent decades, there has been a significant uptick on the use of platelet-rich plasma (PRP) as a better alternative for ophthalmologic therapies in pathologies, primarily of the ocular surface. PRP is a class of liquid platelet concentrate containing a supra-physiological concentration of platelets in a relatively small amount of plasma. Its potential to heal various tissues has piqued interest in its therapeutic application as a biomaterial in regenerative medicine. It is currently a popular therapeutic agent in plastic surgery, cardiothoracic surgery, reconstructive surgery, and even oral and maxillofacial surgery. Based on the data from in vitro and in vivo studies, it can be concluded that PRP possesses adequate therapeutic potential in ocular pathologies, especially those involving cornea. In addition, the high concentrations of growth factors (TGF-β, VEGF, EGF) present in the PRP accelerate the healing of the corneal epithelium. PRP has great therapeutic prospects in veterinary ophthalmology as a regenerative therapeutic modality. However, several variables are yet to be defined and standardized that can directly affect the efficacy of PRP application in different ophthalmic conditions. There is a shortage of research on the use of PRP in ocular surface defects compared to the number of studies and reports on the use of autologous and allogeneic serum eye drops. Therefore, a data-driven approach is required to generate consensus/guidelines for the preparation, characterization, and therapeutic use of PRP in veterinary ophthalmology. This review aims to inform readers of the latest research on PRP, including its preparation methods, physiological and biochemical properties, clinical applications in veterinary ophthalmology, and their safety and efficacy.

Platelet- Rich Plasma Treatment Supported by Ultrasound Detection of Septa in Recurrent Canine Aural Hematoma: A Case Series

Aural hematoma is a common pathological condition in veterinary practice with a high incidence rate in dogs. Drainage, corticosteroid injections, and surgical approaches represent the common treatments in these clinical cases. However, surgery leaves visible signs and is usually correlated with recurrence, scars, and deformation of the treated pinna. For this reason, more effective and less invasive methods have been proposed over the years. Platelet-Rich Plasma (PRP) is one of the most promising options due to its pro-regenerative properties and capability to modulate the inflammatory state. The present work reports 12 cases of canine aural hematoma treated with PRP. The PRP treatment was combined with an ultrasound evaluation of the pinna to detect and treat all involved septa. The results show that relatively large volumes (2 mL) of PRP associated with an ultrasound guide are safe and efficacious in the treatment of canine aural hematoma requiring a maximum of two infiltrations, both in acute and chronic conditions. All the patients recovered their normal ear thickness (compared with the controlateral one) without relapses, averaging 38.5 days from their first treatment (10-90 days; SD: 24.7). The key role of PRP combined with a tailored diagnosis process carried out by the veterinarian, which included using an ultrasound system and the proper bandage, suggests that this approach may represent a valid alternative to surgery and corticosteroids.

Assessment of the quality of the healing process in experimentally induced skin lesions treated with autologous platelet concentrate associated or unassociated with allogeneic mesenchymal stem cells: preliminary results in a large animal model

Regenerative medicine for the treatment of skin lesions is an innovative and rapidly developing field that aims to promote wound healing and restore the skin to its original condition before injury. Over the years, different topical treatments have been evaluated to improve skin wound healing and, among them, mesenchymal stem cells (MSCs) and platelet-rich plasma (PRP) have shown promising results for this purpose. This study sought to evaluate the quality of the healing process in experimentally induced full-thickness skin lesions treated with PRP associated or unassociated with MSCs in a sheep second intention wound healing model. After having surgically created full-thickness wounds on the back of three sheep, the wound healing process was assessed by performing clinical evaluations, histopathological examinations, and molecular analysis. Treated wounds showed a reduction of inflammation and contraction along with an increased re-epithelialization rate and better maturation of the granulation tissue compared to untreated lesions. In particular, the combined treatment regulated the expression of collagen types I and III resulting in a proper resolution of the granulation tissue contrary to what was observed in untreated wounds; moreover, it led to a better maturation and organization of skin adnexa and collagen fibers in the repaired skin compared to untreated and PRP-treated wounds. Overall, both treatments improved the wound healing process compared to untreated wounds. Wounds treated with PRP and MSCs showed a healing progression that qualitatively resembles a restitutio ad integrum of the repaired skin, showing features typical of a mature healthy dermis.

Human Platelet-Rich Plasma Regulates Canine Mesenchymal Stem Cell Migration through Aquaporins

Platelet products are commonly used in regenerative medicine due to their effects on the acceleration and promotion of wound healing, reduction of bleeding, synthesis of new connective tissue, and revascularization. Furthermore, a novel approach for the treatment of damaged tissues, following trauma or other pathological damages, is represented by the use of mesenchymal stem cells (MSCs). In dogs, both platelet-rich plasma (PRP) and MSCs have been suggested to be promising options for subacute skin wounds. However, the collection of canine PRP is not always feasible. In this study, we investigated the effect of human PRP (hPRP) on canine MSCs (cMSCs). We isolated cMSCs and observed that hPRP did not modify the expression levels of the primary class of major histocompatibility complex genes. However, hPRP was able to increase cMSC viability and migration by at least 1.5-fold. hPRP treatment enhanced both Aquaporin (AQP) 1 and AQP5 protein levels, and their inhibition by tetraethylammonium chloride led to a reduction of PRP-induced migration of cMSCs. In conclusion, we have provided evidence that hPRP supports cMSC survival and may promote cell migration, at least through AQP activation. Thus, hPRP may be useful in canine tissue regeneration and repair, placing as a promising tool for veterinary therapeutic approaches.

Autologous platelet-rich fibrin promotes wound healing in cats

Street cats commonly present large skin wounds that pose significant challenges in veterinary practice. Platelet-rich fibrin (PRF) is a second-generation platelet concentrate increasingly used in humans to promote wound healing. Ease of use and clinical success in humans has prompted interest in using PRF in veterinary practice. However, until now, there is no reported study on the use of autologous PRF in feline wound management. This study evaluated the effect of application of autologous PRF in cats with naturally occurring cutaneous wounds. 16 cats with full-thickness cutaneous acute/subacute wounds were randomly allocated to PRF or Control (standard care) groups. Each cat was enrolled for 2 weeks. PRF was prepared according to previously described procedures. PRF was applied on Days 1 and 4 in addition to standard wound care. Wound size was measured using tracing planimetry. Wound surface area was calculated using SketchAndCalc^™ software on scanned tracing images. Average wound sizes at enrolment were 8.39 cm² (Control) (standard deviation (SD) 5.08 cm²) and 9.18 cm² (PRF) (SD 3.71 cm²) (range 2.42-15.97 cm²). By Day 14, the mean wound size for the Control group was 2.17 cm² (SD 1.52 cm²) and for the PRF was 0.62 cm² (SD 0.44 cm²) (p = 0.015). At Day 14, the PRF group showed mean 93.85% wound contraction with SD 3.66, while the control group showed mean 76.23% wound contraction with SD 5.30 (p = <0.0001). Based on the results, PRF could be further investigated to promote wound healing in cats as a low-risk and convenient adjunctive therapy.

Regenerative Medicine and Rehabilitation Therapy in the Canine

Regenerative medicine is used in the canine to optimize tissue healing and treat osteoarthritis and soft tissue injuries. Rehabilitation therapy is also often implemented in the treatment and management of musculoskeletal conditions in the canine. Initial experimental studies have shown that regenerative medicine and rehabilitation therapy may work safely and synergistically to enhance tissue healing. Although additional study is required to define optional rehabilitation therapy protocols after regenerative medicine therapy in the canine, certain fundamental principles of rehabilitation therapy still apply to patients treated with regenerative medicine.

Owner assessed outcomes following elbow arthroscopy with or without platelet rich plasma for fragmented medial coronoid process

Objective

Document the outcomes of bilateral arthroscopic subtotal coronoidectomy for the fragmented medial coronoid process, quantify persistent lameness that required additional treatment (PRP), and document the outcomes of dogs that followed up with PRP injections.

Study design

Retrospective study.

Sample population

Overall, 115 dogs underwent arthroscopy alone and 31 received PRP at least 6 weeks after arthroscopy. The owner's response rate was ~50% (73 dogs).

Methods

Collected data included signalment, unilateral or bilateral clinical signs, intra-articular chondroprotective injection during the procedure, if PRP intra-articular injection was received postoperatively, and if it was received, the time from the initial surgery to administration was recorded. Outcomes were assessed via standardized owner questionnaires using the Liverpool Osteoarthritis in Dogs (LOAD) score, the Canine Brief Pain Inventory (CBPI) score, and the overall quality of life (QOL) assessment.

Results

Approximately 20% of the patients received PRP post-operatively due to persistent lameness following surgery. Similar pain scores were found between the two groups with an average of 11–13 LOAD score, 13–15 CBPI score, and good quality of life. Older animals at the time of surgery and those that received pain-relieving medications after the procedure were more painful and affected their functional outcome. PRP as an adjunctive therapy achieved a perceived good to excellent quality of life in ~90% of pets in this population.

Conclusion

Arthroscopy and subtotal coronoidectomy followed by PRP, if needed, seemed to decrease pain, and improve lameness in the long term.

Clinical significance

PRP should be considered as adjunctive therapy in dogs with the limited response to arthroscopy alone.

Platelet-Rich Plasma as an Orthobiologic: Clinically Relevant Considerations

Platelet-rich plasma (PRP) is an autologous blood-derived product processed to concentrate platelets and the associated growth factors. PRP has been shown to be relatively well-tolerated and safe to use for a number of conditions in humans, equines, and canines. There are multiple commercial systems that have been validated for canine use. These systems use a variety of methodologies to produce a PRP product. However, PRP products have been shown to differ greatly between systems. Further study is needed to fully elucidate optimal component concentrations for various indications.

Platelet Lysate for Mesenchymal Stromal Cell Culture in the Canine and Equine Species: Analogous but Not the Same

Simple Summary

Regenerative medicine using platelet-based blood products or adult stem cells offers the prospect of better clinical outcomes with many diseases. In veterinary medicine, most progress has been made with the development and therapeutic use of these regenerative therapeutics in horses, but the clinical need is given in dogs as well. Our aim was to transfer previous advances in the development of horse regenerative therapeutics, specifically the use of platelet lysate for feeding stem cell cultures, to the dog. Here, we describe the scalable production of canine platelet lysate, which could be used in regenerative biological therapies. We also evaluated the canine platelet lysate for its suitability in feeding canine stem cell cultures in comparison to equine platelet lysate used for equine stem cell cultures. Platelet lysate production from canine blood was successful, but the platelet lysate did not support stem cell culture in dogs in the same beneficial way observed with the equine platelet lysate and stem cells. In conclusion, canine platelet lysate can be produced in large scales as described here, but further research is needed to improve the cultivation of canine stem cells.

Abstract

Platelet lysate (PL) is an attractive platelet-based therapeutic tool and has shown promise as xeno-free replacement for fetal bovine serum (FBS) in human and equine mesenchymal stromal cell (MSC) culture. Here, we established a scalable buffy-coat-based protocol for canine PL (cPL) production (n = 12). The cPL was tested in canine adipose MSC (n = 5) culture compared to FBS. For further comparison, equine adipose MSC (n = 5) were cultured with analogous equine PL (ePL) or FBS. During canine blood processing, platelet and transforming growth factor-β1 concentrations increased (p < 0.05 and p < 0.001), while white blood cell concentrations decreased (p < 0.05). However, while equine MSC showed good results when cultured with 10% ePL, canine MSC cultured with 2.5% or 10% cPL changed their morphology and showed decreased metabolic activity (p < 0.05). Apoptosis and necrosis in canine MSC were increased with 2.5% cPL (p < 0.05). Surprisingly, passage 5 canine MSC showed less genetic aberrations after culture with 10% cPL than with FBS. Our data reveal that using analogous canine and equine biologicals does not entail the same results. The buffy-coat-based cPL was not adequate for canine MSC culture, but may still be useful for therapeutic applications.

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.

Therapeutic Potential of Platelet-Rich Plasma in Canine Medicine

Platelets are the reservoir of growth factors and play a major role in several physiological processes, such as coagulation, angiogenesis, immune response, and tissue repair. Platelet concentrates are broadly classified into two groups depending on their fibrin content, namely platelet-rich plasma (PRP) and platelet-rich fibrin (PRF). They are further divided based on their leucocyte contents. The PRP is plasma containing supra-physiological concentrations of the platelets. The growth factors present in the PRP play a crucial role in the promotion of local angiogenesis, regulation of cellular activity, stem cell homing, proliferation and differentiation of different stem cells, and deposition of matrix proteins contributing to tissue regeneration. This review aimed to establish the therapeutic potential of PRP in canine medicine with a particular focus on the applications in ophthalmology, dermatology, and musculoskeletal disorders. A systematic literature review was performed to identify the literature published during the past 20 years (2001-2021) using authentic academic databases, such as PubMed, Science Direct, Google Scholar, and Scopus. In the initial search, 556 articles were identified and based on the specific inclusion and exclusion criteria, 59 articles were selected for further analysis. The clinical efficacy of PRP depends on the number of platelets and the growth factor concentration. The PRP-based biological therapy has broad clinical applications in musculoskeletal pathologies. It is a simple, safe, and cost-effective method that can be used to treat various diseases and disorders in canine practice. For example, PRP is used for managing corneal ulcers, corneal erosion, alkali burn, keratoconjunctivitis sicca, burn wounds, chronic wounds, cutaneous ulcers, acute traumatic bone fractures, tendinopathies, cartilage pathologies, osteoarthritis, and abdominal wall defects either as monotherapy or as an adjunctive therapeutic agent. In addition, PRP is widely used as a carrier of mesenchymal stem cells for transplanting into bone defects. Therefore, allogeneic PRP therapy can be considered a simple, safe, and cost-effective method for the treatment of various diseases and disorders in canine practice. The therapeutic application of PRP in canine medicine is limited in the present study due to the lack of consensus for collection, characterization, and clinical use. Hence, further studies are required to establish the actual worth of PRP-based regenerative strategies in canine medicine.

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.

Characterization and Therapeutic Use of Extracellular Vesicles Derived from Platelets

Autologous blood products, such as platelet-rich plasma (PRP), are gaining increasing interest in different fields of regenerative medicine. Although growth factors, the main components of PRP, are thought to stimulate reparation processes, the exact mechanism of action and main effectors of PRP are not fully understood. Plasma contains a high amount of extracellular vesicles (EVs) produced by different cells, including anucleated platelets. Platelet-derived EVs (PL-EVs) are the most abundant type of EVs in circulation. Numerous advantages of PL-EVs, including their ability to be released locally, their ease of travel through the body, their low immunogenicity and tumourigenicity, the modulation of signal transduction as well as the ease with which they can be obtained, has attracted increased attention n. This review focuses briefly on the biological characteristics and isolation methods of PL-EVs, including exosomes derived from platelets (PL-EXOs), and their involvement in the pathology of diseases. Evidence that shows how PL-EVs can be used as a novel tool in medicine, particularly in therapeutic and regenerative medicine, is also discussed in this review.

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.

Platelet-Rich Plasma-Derived Exosomal USP15 Promotes Cutaneous Wound Healing via Deubiquitinating EIF4A1

Epithelial regeneration is an essential wound healing process, and recent work suggests that different types of exosomes (Exos) can improve wound repair outcomes by promoting such epithelial regeneration. Platelet-rich plasma (PRP) is known to facilitate enhanced wound healing, yet the mechanisms underlying its activity are poorly understood. To explore these mechanisms, we first isolated PRP-derived Exos (PRP-Exos). Using immortalized keratinocytes (HaCaT cells) treated with PBS, PRP, or PRP-Exos, we conducted a series of in vitro Cell Counting Kit-8 (CCK-8), EdU, scratch wound, and transwell assays. We then established a wound defect model in vivo in mice and assessed differences in the mRNA expression within these wounds to better understand the basis for PRP-mediated wound healing. The functions of PRP-Exos and USP15 in the context of wound healing were then confirmed through additional in vitro and in vivo experiments. We found that PRP-Exos effectively promoted the in vitro proliferation, migration, and wound healing activity of HaCaT cells. USP15 was further identified as a key mediator through which these PRP-Exos were able to promote tissue repair both in vitro and in vivo. At a mechanistic level, USP15 enhanced the functional properties of HaCaT cells by promoting EIF4A1 deubiquitination. Thus, PRP-Exos and USP15 represent promising tools that can promote wound healing via enhancing epithelial regeneration.

A Prototype Skin Substitute, Made of Recycled Marine Collagen, Improves the Skin Regeneration of Sheep

Simple Summary

Marine ecosystems are a huge source of unexplored “blue” materials for different applications. The edible part of sea urchin is limited, and the vast majority of the product ends up as waste. Our studies intend to fully recycle wastes from the food industry and reconvert them in high added-value products, as innovative biocompatible skin substitutes for tissue regeneration. The aim of the present work is to apply the pioneering skin substitute in in vivo experimental wounds to test its regenerative potential and compare it, in a future study, to the available commercial membranes produced with collagen of bovine, porcine, and equine origin. Results are encouraging since the skin substitute made with marine collagen reduced inflammation, promoted the deposition of granulation tissue, and enhanced a proper re-epithelialization with the adequate development of skin appendages. In summary, our findings might be of great interest for processing industries and biotech companies which transform waste materials in high-valuable and innovative products for Veterinary advanced applications.

Abstract

Skin wound healing is a complex and dynamic process that aims to restore lesioned tissues. Collagen-based skin substitutes are a promising treatment to promote wound healing by mimicking the native skin structure. Recently, collagen from marine organisms has gained interest as a source for producing biomaterials for skin regenerative strategies. This preliminary study aimed to describe the application of a collagen-based skin-like scaffold (CBSS), manufactured with collagen extracted from sea urchin food waste, to treat experimental skin wounds in a large animal. The wound-healing process was assessed over different time points by the means of clinical, histopathological, and molecular analysis. The CBSS treatment improved wound re-epithelialization along with cell proliferation, gene expression of growth factors (VEGF-A), and development of skin adnexa throughout the healing process. Furthermore, it regulated the gene expression of collagen type I and III, thus enhancing the maturation of the granulation tissue into a mature dermis without any signs of scarring as observed in untreated wounds. The observed results (reduced inflammation, better re-epithelialization, proper development of mature dermis and skin adnexa) suggest that sea urchin-derived CBSS is a promising biomaterial for skin wound healing in a “blue biotechnologies” perspective for animals of Veterinary interest.