Effect of Topical Platelet-Rich Plasma on Burn Healing After Partial-Thickness Burn Injury

Platelet-derived biomaterial controls aspergillus fumigatus keratitis by decreasing fungal burden: an in vivo study

Fungal keratitis is a severe corneal infection characterized by suppurative and ulcerative lesions. Aspergillus fumigatus is a common cause of fungal keratitis. Antifungal drugs, such as natamycin, are currently the first-line treatment for fungal keratitis, but their ineffectiveness leads to blindness and perforation. Additionally, the development of fungal resistance makes treating fungal keratitis significantly more challenging. The present study used platelet-derived biomaterial (PDB) to manage A. fumigatus keratitis in the animal model. Freezing and thawing processes were used to prepare PDB, and then A. fumigatus keratitis was induced in the mice. Topical administration of PDB, natamycin, and plasma was performed; quantitative real-time PCR (qPCR) and histopathologic examination (HE) were used to assess the inhibitory effect of the mentioned compounds against fungal keratitis. The qPCR results showed that PDB significantly decreased the count of A. fumigatus compared to the control group (P-value ≤ 5). Natamycin also remarkably reduced the count of fungi in comparison to the untreated animal, but its inhibitory effect was not better than PDB (P-value > 5). The findings of HE also demonstrated that treatment with PDB and natamycin decreased the fungal loads in the corneal tissue. However, plasma did not show a significant inhibitory effect against A. fumigatus. PDB is intrinsically safe and free of any infections or allergic responses; additionally, this compound has a potential role in decreasing the burden of A. fumigatus and treating fungal keratitis. Therefore, scientists should consider PDB an applicable approach to managing fungal keratitis and an alternative to conventional antifungal agents.

Sodium alginate/carboxycellulose/polydopamine composite microspheres for rapid hemostasis of deep irregular wounds

Hemostasis of deep irregular wounds is a severe problem in clinical practice. The development of rapid-acting hemostatic agents for deep and irregular wound is urgently needed. Here, sodium alginate/carboxycellulose/polydopamine (SA/CNF/PDA) microspheres was prepared by reverse emulsification and crosslinking with Ca2+, and SA/CNF/PDA composite hemostatic microspheres with porous structure were obtained by freeze-drying. SA/CNF/PDA composite hemostatic microspheres exhibited excellent porosity and water absorption which could rapidly absorb blood on the wound surface. Moreover, SA/CNF/PDA composite microspheres demonstrated remarkable hemostatic capabilities both in vitro and in vivo. It exhibited strong hemostatic performance in models of mouse tail-break and liver damage. Especially in liver injury model, it was completely hemostatic in 95 s, and blood loss (19.3 mg). The hemostatic efficacy of the SA/CNF/PDA composite microspheres was amplified through the stimulation of both exogenous and endogenous coagulation pathways. Therefore, SA/CNF/PDA composite hemostatic microspheres are suitable for rapid hemostasis of deep irregular wounds which are potential rapid hemostatic material for surgical application.

Platelet-derived exerkine CXCL4/platelet factor 4 rejuvenates hippocampal neurogenesis and restores cognitive function in aged mice

The beneficial effects of physical activity on brain ageing are well recognised, with exerkines, factors that are secreted into the circulation in response to exercise, emerging as likely mediators of this response. However, the source and identity of these exerkines remain unclear. Here we provide evidence that an anti-geronic exerkine is secreted by platelets. We show that platelets are activated by exercise and are required for the exercise-induced increase in hippocampal precursor cell proliferation in aged mice. We also demonstrate that increasing the systemic levels of the platelet-derived exerkine CXCL4/platelet factor 4 (PF4) ameliorates age-related regenerative and cognitive impairments in a hippocampal neurogenesis-dependent manner. Together these findings highlight the role of platelets in mediating the rejuvenating effects of exercise during physiological brain ageing.

Effects of platelet-rich plasma on the memory impairment, apoptosis, and hippocampal synaptic plasticity in a rat model of hepatic encephalopathy

OBJECTIVES

In the present study, we aimed to determine whether intraperitoneal injection of platelet-rich plasma (PRP) could have a neuroprotective effect on learning, memory, and synaptic plasticity impairment as well as hippocampal apoptosis in rats with hepatic encephalopathy induced by bile duct ligated (BDL).

METHODS

The rats were divided into four groups: the control, sham, BDL+ V (vehicle), and BDL+ PRP. The BDL rats were treated with PRP immediately after the surgery, and the injection was done every 3 days for 30 days. The passive avoidance and Morris water maze tests were used for the evaluation of learning and memory. The long-term potentiation (LTP), basal-synaptic transmission, and paired-pulse ratio, as an index for measurement of neurotransmitter release probability, were evaluated by field-potential recording. After taking a blood sample for assessment of the liver enzymes, the animals were sacrificed and their hippocampus was removed for evaluation of cleaved caspase-3 by Western blot.

RESULTS

Serological assessment of the liver function showed that BDL severely impaired the liver function. Also, PRP treatment could partially improve the liver dysfunction along with recovery in fear memory and spatial learning memory performance, LTP, basal-synaptic transmission, and neurotransmitter release probability. PRP-treated rats also showed a significant reduction in neuronal apoptosis in the CA1 area.

CONCLUSIONS

The results of this study suggest that PRP improves cognitive performance and synaptic plasticity in BDL rats via direct neuroprotective property and/or indirectly by improvement of hepatic dysfunction.

The Role of Autologous PRP on Deep Partial-Thickness Burn Wound Healing in Bama Pigs

In this study, we aimed to evaluate the therapeutic effects of autologous platelet-rich plasma (PRP) on deep partial-thickness burns in Bama pigs. Deep partial-thickness burn wounds were created on the back of Bama pigs. The reepithelialization time was compared between the PRP and control groups. The mean score of Ki67 (+) cells and α-SMA (+) vessels, the mean thickness of epidermis and dermis of the healing wounds were determined via H&E staining and immunohistochemical assay. The levels of the growth factors epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), and vascular endothelial growth factor (VEGF) were examined by ELISA. Our data showed that the time to wound reepithelialization was shorter in the PRP group compared with the control group. The thickness of the epidermis was larger in the PRP group compared with the control group. On the 7th and 14th days after the treatment, the mean score of Ki67 (+) cells and α-SMA (+) vessels were higher in the PRP group compared with the control group. The PRP group showed higher levels of growth factors (EGF, bFGF, and VEGF) compared with the control group by ELISA. The results indicated that PRP could improve wound healing process of deep partial-thickness burns in Bama pigs. The PRP increased the thickness of epidermis of the healed wounds, cell proliferation, and angiogenesis. We demonstrated that applying PRP had a greater potential for the treatment of deep partial-thickness burns.

Effect of Subcutaneous Topical Ozone Therapy on Second-Degree Burn Wounds in Rats: An Experimental Study

Burns are one of the most severe traumas, causing coagulative destruction of the skin. The use of various products that accelerate wound healing in patients with burns may affect rates of patient survival and reduce complications. We studied the effects of subcutaneous ozone injection on second-degree burn wounds in animal model. For this study, 72 Sprague-Dawley male rats were divided randomly into the following three groups: control group , silver sulfadiazine group, and ozone group; each group was then divided randomly into two subgroups (day 7 or day 14 examination and sacrifice). Superficial partial thickness burns were created on the lower back. In the control group, subcutaneous 0.9% serum saline was injected daily into the burn area. In the silver sulfadiazine group, burns were dressed daily with silver sulfadiazine. In the ozone group, subcutaneous ozone was injected daily into the burn area. We performed tissue hydroxyproline level measurements and histopathological evaluations. When groups were compared in terms of weight change, no significant difference was found between day 7 and day 14. With regard to tissue hydroxyproline levels the ozone group had significantly higher levels on both day 7 and day 14 (P < .001). In histopathological evaluations, we determined that wound healing in the ozone group was significantly higher than in the other groups. We found that subcutaneous ozone therapy was more effective than silver sulfadiazine in the healing process of second-degree burn wounds and could be safely used in the treatment of burn wounds.

Investigation into antibacterial and wound healing properties of platelets lysate against Acinetobacter baumannii and Klebsiella pneumoniae burn wound infections

Background and aim

Treatment of burn wound infections has become a global challenge due to the spread of multidrug-resistant bacteria; therefore, the development of new treatment options for the mentioned infections is essential. Platelets have drawn much attention for this purpose because they are a safe and cost-effective source of different antimicrobial peptides and growth factors. The present study evaluated antibacterial effects and wound healing properties of Platelet-derived Biomaterial (PdB) against Acinetobacter baumannii and Klebsiella pneumoniae burn wound infections.

Methods

PdB was prepared through the freezing and thawing process and then, in vitro antibacterial effect was determined by disk diffusion and broth microdilution methods. Afterward, burn wound was inflicted on 56 rats, infected with both bacteria, and topical administration was performed to evaluate antibacterial effects and wound healing properties of PdB.

Results

In vitro results showed that PdB inhibited the growth of A. baumannii in the highest dose (0.5), while we did not detect any inhibitory effects against K. pneumoniae. By contrast, PdB significantly inhibited the growth of bacteria in treated animal wounds compared to the control groups (P value < 0.05). Macroscopic assessments pointed to the significant enhancement of wound closure in the treated animals. In addition, histopathological examination demonstrated that treatment of rats with PdB led to a considerable increase in re-epithelialization and attenuated the formation of granulation tissue (P value < 0.05).

Conclusion

The use of topical PdB is an attractive strategy for treating A. baumannii and K. pneumoniae burn wound infections because it inhibits bacterial growth and promotes wound healing properties.

[Not Available]

Platelet rich plasma (PRP) has trophic functions due to a high concentration of growth factors and cytokines. These properties may be of therapeutic interest in the management of burn injuries. In preparation for a clinical study at the Lyon Burn Centre on PRP as an inducer of healing in burns, we carried out a review of the literature looking at the results of the use of this therapy. A review of the literature on the use of PRP for the treatment of burn injuries was performed by querying the PUBMED database using the keywords [platelet rich plasma] AND [burns]. Controlled clinical or pre-clinical studies in English or French were included. Eleven articles were identified, consisting of eight preclinical animal model studies and three clinical studies. These looked at the effects of PRP on the healing of burned areas whether they were grafted or not, on the improvement of neuropathic pain, and on distant skin trophicity. The results of recent preclinical studies show shorter epithelialization times thanks to PRP. In humans, a significant study (201 patients) validates its use in combination with thin skin grafts, and another shows benefits on distant cutaneous trophicity. In conclusion, the use of PRP topically or by injection under the skin has a potential benefit in the management of acute burns. A large-scale series validates its use in clinical practice.

Exploring Cadaver Skin For Standardization Of Rabbit And Porcine Burn Models In Research

Burn animal models provide substantial insights into burn pathophysiology. Choice of the apt model is important for determining the clinical efficacy of new medicines. Therefore, standardization of burn models is crucial for scientific research. Use of common techniques like hot water, electricity and incandescent instruments to generate animal burn models is widely reported. However, great discrepancy in employed temperature and exposure times demands user-dependent standardization of the animal model prior to research. Establishment of custom generated in vivo burn models giving consideration to reduced use, suffering and risk of the experimental animal is equally crucial. Accordingly, this pilot study demonstrates a novel approach using rabbit and porcine cadaver skin for standardization of burn parameters prior to use in live animal models. Using a custom-made soldering iron coupled to a 16cm2 surface area copper plate, burns at randomly chosen temperatures of 80˚C and 120˚C, with exposure times ranging from 60s to 180s, were produced on rabbit and porcine cadaver skins. On gross and histopathological analysis, parameters required to generate characteristic changes for deep partial and full thickness burn involvement were established. The identified temperature and exposure time parameters were further validated in live animal models. In vivo validation established the success of this approach, highlighting reduced animal use, ease, reproducibility and efficacy in burn model standardization. The findings of this study will hopefully encourage researchers to opt for cadaver skin to determine parameters required to generate a specific degree of burn prior to its use in live animals for burn research.

Combination of platelet-rich plasma and stromal vascular fraction on the level of transforming growth factor-β in rat subjects experiencing deep dermal burn injury

INTRODUCTION

The combination of stromal vascular fraction (SVF) and platelet-rich plasma (PRP) is effective at increasing the concentration of growth factors including transforming growth factor-β (TGF-β). The increase in this growth factor is expected to accelerate the healing of burns. This study aims to determine the effect of giving a combination of SVFs and PRP on TGF-β levels in the healing process of deep dermal burns.

METHODS

This was an experimental study in 64 rats using a post-test control group design consisting of 1 group of SVFs and PRP combination injection treatment group, 1 group given a topical combination of SVFs and PRP, 1 group given Vaseline, and 1 control group.

RESULTS

There was a significant difference in TGF-β levels between the deep dermal burns group that was given a combination of SVFs and PRP injection and topical, the Vaseline group, and the control group with p-value <0.05.

CONCLUSION

The combination of SVFs and PRP increases the level of TGF-β in the healing process of deep dermal burns.

Platelets in Neurodegenerative Conditions-Friend or Foe?

It is now apparent that platelet function is more diverse than originally thought, shifting the view of platelets from blood cells involved in hemostasis and wound healing to major contributors to numerous regulatory processes across different tissues. Given their intriguing ability to store, produce and release distinct subsets of bioactive molecules, including intercellular signaling molecules and neurotransmitters, platelets may play an important role in orchestrating healthy brain function. Conversely, a number of neurodegenerative conditions have recently been associated with platelet dysfunction, further highlighting the tissue-independent role of these cells. In this review we summarize the requirements for platelet-neural cell communication with a focus on neurodegenerative diseases, and discuss the therapeutic potential of healthy platelets and the proteins which they release to counteract these conditions.

Wound healing properties and antimicrobial activity of platelet-derived biomaterials

We analyzed the potential antibacterial effects of two different PdB against methicillin-resistant S. aureus and P. aeruginosa. The third-degree burn wound healing effects of PdB was also studied. Blood samples were obtained from 10 healthy volunteers and biological assays of the PdB were performed and the antimicrobial activity against MRSA and P. aeruginosa was determined using disk diffusion (DD), broth microdilution (BMD), and time-kill assay methods. 48 Wistar albino rats were burned and infected with MRSA. Two groups were injected PdB, the control groups were treated with plasma and received no treatment respectively. In the next step, the rats were euthanized and skin biopsies were collected and histopathologic changes were examined. The results of DD and BMD showed that both PdB performed very well on MRSA, whereas P. aeruginosa was only inhibited by F-PdB and was less susceptible than MRSA to PdBs. The time-kill assay also showed that F-PdB has an antibacterial effect at 4 hours for two strains. Histopathological studies showed that the treated groups had less inflammatory cells and necrotic tissues. Our data suggest that PdB may possess a clinical utility as a novel topical antimicrobial and wound healing agent for infected burn wounds.

Plasma-Alginate Composite Material Provides Improved Mechanical Support for Stem Cell Growth and Delivery

Blood plasma-based products have been recently utilized in different tissue engineering applications, ranging from soft tissue repair to bone regeneration. Plasma contains fibrinogen which can be converted to an insoluble fibrin-laden gel in the presence of activated thrombin. In tissue engineering, these plasma-based materials can serve either as a three-dimensional scaffold to deliver therapeutic cells in vivo or as a growth factor-rich supply for tissue regeneration. Unfortunately, plasma-based materials are often mechanically weak and easily deformed, thus limiting their usability in harsh clinical settings. Simpler methods to create sturdier plasma-based materials are therefore needed. To this end, we hypothesized that combining alginate with plasma can create a composite plasma material with improved mechanical properties. Incorporating alginate into plasma produced composite gels with increasing bulk stiffness, as measured by rheology. Specifically, the plasma-alginate composite (PAC) gels with an alginate concentration of 2.86 mg/mL were 10-fold stiffer than pure plasma gels (11 vs 112 Pa). Interestingly, gel lysis rates were unchanged despite increasing alginate concentration (lysis time approximately 50 min). Adipose-derived stem cells cultured in the stiffer PAC gels expressed stemness markers (THY1, ENG, NT5E) at levels comparable to those in the pure plasma gels. Similarly, proangiogenic factor secretion was also constant across all gel conditions. In sum, we envision this PAC gel system will extend the use of plasma gel-based therapies into more rigorous clinical applications.

Developing a Simple Burn Model in Rats of Different Ages

This article describes a simple and safe model of partial and full thickness burn injury in rats of different ages, which will be essential in our future burn research to explore the age-related mechanism of wound repair and new therapies for burn injuries. A self-made metal column, which was heated in a boiling water bath, was applied for different time periods to the lower back of rats of different ages in burn creation. Wounds were observed visibly at different time points postburn. Biopsies were obtained and examined at 72-hour postburn to determine the depth of burns. The contact durations producing the desired depth of injury in the rat model under constant temperature and pressure were: 3 seconds (deep second degree) and 5 seconds (third degree) in 1-month-old rats; 3 seconds (superficial second degree), 5 seconds (deep second degree), and 7-9 seconds (third degree) in 2-month-old rats; 3-5 seconds (superficial second degree), 7-9 seconds (deep second degree), and 11-13 seconds (third degree) in 12- and 18-month-old rats. This reliable and reproducible experimental model produces consistent burn injuries in rats of different ages by regulating the contact durations, which will help us to understand the underlying pathophysiology of burn injuries and develop novel therapeutic modalities for burn patients of different ages.

Platelet-rich plasma, a powerful tool in dermatology

Platelet-rich plasma (PRP), a platelet concentrate contained in a small volume of plasma, has become a promising option in the last decade to treat different diseases related to the skin due to its high concentration of growth factors. When it is of autologous origin, it decreases the probability of suffering adverse reactions and transfusion-transmitted infections, thus it is an optimal and safe therapy for the patient. PRP has been used in the treatment of several dermatological conditions such as acne, alopecia, and skin ulcers. Its use has also extended to other skin conditions such as melasma, hyperpigmentation, and burns, where it stimulates tissue repair and regeneration. The purpose of this article is to review the management and treatment of different dermatological alterations with PRP. Although there are a variety of studies that support the use of PRP, more research is needed to standardise the protocols for obtaining, processing, and applying it as well as understanding the biological and molecular bases of its functioning.

The effects of Platelet-rich Plasma on healing of partial thickness burns in a porcine model

Platelet-rich plasma (PRP) derived from autologous peripheral blood is rich in platelets that release growth factors and cytokines. We determined the effects of topically applied autologous PRP in a partial thickness porcine burn model. Partial thickness burns were created on the backs and flanks of six domestic pigs (24 burns each) using an aluminium bar preheated to 80° C for 20 seconds. After removing the necrotic epidermis, the burns were randomly treated with a topical antibiotic ointment or a single (day 2), double (days 2 and 7), or triple (days 2, 7, and 14) topical application of PRP that was prepared freshly before application. Periodic imaging and full thickness biopsies were conducted to monitor healing over 28 days. The percentage wound reepithelialization at days 11, 14, 18 and 21 did not differ significantly among the groups. By day 28 all wounds were completely (>95%) reepithelialized, and there were no differences among the groups. Time to complete healing (presented as mean, [SD]) did not differ among the groups (antibiotics, 17.1 [3.5]; single PRP, 17.6 [4.0]; double PRP, 18.4 [3.9]; and triple PRP, 17.7 [3.3] days; ANOVA P=0.43). Scar depth (presented as mean, [SD]) in mm at day 28 by treatment group was: antibiotic 5.0 [1.0], single PRP 5.5 [1.1], double PRP 5.4 [1.1], and triple PRP 5.5 [0.6], ANOVA P=0.026. We conclude that PRP results in similar rates of reepithelialization and scar depth to standard topical antibiotics in a partial thickness porcine burn model.

Analysis of the effect of subcutaneous injection of omental-derived cells on the healing of third degree burns in rats: a preliminary study

Burn injury is considered a global health issue. Third degree burn wounds do not heal spontaneously and require skin grafts. Some factors could contribute to wound healing. In this study we assessed the effect of non-fatty omental cells in burn wound healing. Similar third degree burn wounds were induced on the back of 192 rats. Forty-eight of these rats were put in a control group that did not receive any treatment. The rest of the rats were put in 3 groups, each receiving a different treatment regime. Rats in group 2 had a daily application of silver sulfadiazine; group 3 rats were injected with omental cells, and group 4 rats were injected with phosphate buffer saline (PBS) once, followed by daily application of Vaseline to the burned region. Parameters such as open epidermis length, number of epidermal cell layers, granulation tissue thickness (GTT) and neutrophil density were evaluated in each group. The average open epidermis length in the omental cell group was less than in the other groups on days 10 and 20 (P<0.05). The thickness of epidermal cell layers in the group receiving cells was greater than in the other groups on all days. On the 20th day, there was a significant difference in GTT between the four groups (P<0.05). The injection of non-fatty omental cells has a positive effect on third degree burn wounds in rats.

Can mesenchymal stem cells pretreated with platelet-rich plasma modulate tissue remodeling in a rat with burned skin?

Our aim was to study the effect of platelet-rich plasma (PRP) on the proliferation of bone-marrow-derived mesenchymal stem cells (BM-MSCs) and to investigate their roles in the healing of experimental burn injury and the possible mechanism of action. Our work was divided into in-vitro and in-vivo studies. The in-vitro study included untreated MSCs and MSCs treated with PRP. Levels of TGF-β and cell proliferation were assessed. In the in-vivo study, 72 rats were distributed equally among 6 groups: control, burn, burn with MSCs, burn with PRP, burn with both MSCs and PRP, and burn with MSCs pretreated with PRP. On the 7th and 20th day after injury, the serum levels of transforming growth factor beta (TGF-β) and tumor necrosis factor alpha (TNF-α), as well as interleukin-10 (IL-10) levels in skin tissue were measured by ELISA; histopathology and gene expression of MMP-1, TIMP-2, Ang-1, Ang-2, and vimentin by real-time PCR were performed in all groups. In vitro: proliferation of MSCs and TGF-β increased in the PRP-treated group compared with the control group. In vivo: Ang-1, Ang-2, and vimentin were upregulated, whereas MMP-1 and TIMP-2 were downregulated. TGF-β and IL-10 were increased, whereas TNF-α was decreased in all treated groups with more significance in MSCs and PRP on day 20. Histopathology of burn skin was improved in all treated groups, particularly in MSCs pretreated with PRP 20 days post-burn.