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Light micrograph of incised wound of the rabbit's skin after 3 days. a: The open edges wound with large amount of necrotic debris and fibrin within the incised gap and cover the wound surface as showed by black arrows in zinc oxide group, (H and E stain, 40X). B: The partially closed wound with moderate amount of necrotic debris with fibrin that cover the wound surface as showed by black arrows in PRP group, (H and E stain, 40X). c: Granulation tissue: Slight infiltration of neutrophil (yellow arrows) with underlining neovascularization as indicated by red arrows in zinc oxide group (H and E stain, 100X). d: Granulation tissue: Moderate infiltration of neutrophil (yellow arrows) with underlining neovascularization as indicated by red arrows in the PRP group (H and E stain, 100X).
Source publication
In this study efficiency of platelet rich plasma (PRP) and zinc oxide on full thickness wounds created on rabbits was researched. This study conducted on 24 New Zealand rabbits divided 2 groups. A circular of 1.5 × 1.5 cm (2.5 cm²) full thickness skin wound was created under the general anesthesia. 1 ml PRP (5.503106/mm³) was applied to the one of...
Contexts in source publication
Context 1
... oxide group, wound showed incision gap (not closed well) with large amount of necrotic debris and fibrin cover the surface of wound also within the wound gap, with few underlying neovascularization and infiltration of few numbers of inflammatory cells mainly neutrophil (granulation tissue), and the epithelial surface still absent in this period (Fig. 7 a, c), while, in the PRP group the covering epithelial cells pro- liferate and 'crawl' atop the wound bed, given that cover for the new tissue with underlying markedly neovascularization and considerable number of inflammatory cells mainly neutrophil (granulation tissue) as in ( Fig. 7 b, ...
Context 2
... and the epithelial surface still absent in this period (Fig. 7 a, c), while, in the PRP group the covering epithelial cells pro- liferate and 'crawl' atop the wound bed, given that cover for the new tissue with underlying markedly neovascularization and considerable number of inflammatory cells mainly neutrophil (granulation tissue) as in ( Fig. 7 b, ...
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Background:
Platelet-rich plasma (PRP) treatment may encourage hair growth by promoting cellular maturation, differentiation, and proliferation.
Objective:
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Materials and methods:
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Aim: To affirm that autologous platelet rich plasma is a useful adjunct to early tangential excision and skin grafting to enhance wound epithelization rates and improve scar quality.
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Citations
... A study by Badis et al. (19) showed that PRP reduced inflammation during the first 3 days postsurgery and promoted epithelialization in 3 weeks of healing when compared with placebo. Similar findings were noted by Abdullah et al. (20) in his study on full thickness wounds in rabbits. AFG facilitates wound regeneration by promoting angiogenesis, immunomodulation, differentiation, and proliferation (21). ...
Background: Autologous fat grafts (AFGs) and platelet-rich plasmas (PRPs) are useful adjuncts to healing of chronic wounds. In the resource-limited setting, PRP is the more attractive option owing to its ease of use. There is, however, a paucity of data comparing the two. Methods: In this single-center randomized controlled trial, we recruited 56 participants in the AFG (26) and PRP (30) groups. Bed preparation and standard dressings were done, then AFGs or PRPs were injected at the wound base and peri-wound area. On days 3, 7, 14, 21, and 28 data for epithelialization, granulation, wound contraction, pain, and infections were collected and analyzed using SPSS. Results: Granulation and epithelialization increased from day 0 to 28 in both groups with statistical differences observed on days 0, 14, and 21 (p values = 0.033, 0.002, and 0.002, respectively, for granulation and no significant difference noted for epithelialization). Contraction was observed in both groups from day 0 to 28 with a significant difference noted on days 3 and 7 (p value = 0.015 and 0.004, respectively). Pain decreased from day 0 to 28, with the PRP group recording lower values. There were no infections among the AFG group, while in the PRP group, infections were reported on day 3. Conclusions: PRP provides a viable option over fat graft in the management of chronic wounds.
... [107][108][109] Additionally, topical application of PRP has gained recognition as an effective clinical approach for surgical or wound site(s), promoting tissue repair, reducing inflammation, and accelerating the healing process. [110][111][112] Furthermore, in addition to standalone PRP delivery, clinicians frequently combine PRP with surgical procedures involving bone grafts. This approach aims to optimize the integration of graft materials and enhance the overall success of the surgical intervention. ...
Despite significant advances in the understanding and delivery of osteosynthesis, fracture non-union remains a challenging clinical problem in orthopaedic surgery. To bridge the gap, basic science characterization of fracture healing provides a platform to identify and target biological strategies to enhance fracture healing. Of immense interest, Platelet-rich plasma (PRP) is a point of care orthobiologic that has been extensively studied in bone and soft tissue healing given its relative ease of translation from the benchtop to the clinic. The aim of this narrative review is to describe and relate pre-clinical in-vitro and in-vivo findings to clinical observations investigating the efficacy of PRP to enhance bone healing for primary fracture management and non-union treatment. A particular emphasis is placed on the heterogeneity of PRP preparation techniques, composition, activation strategies, and delivery. In the context of existing data, the routine use of PRP to enhance primary fracture healing and non-union management cannot be supported. However, it is acknowledged that extensive heterogeneity of PRP treatments in clinical studies adds obscurity; ultimately, refinement (and consensus) of PRP treatments for specific clinical indications, including repetition studies are warranted.
... According to several in vivo studies, zinc oxide revealed anti-inflammatory properties [39][40][41], accelerating the wound healing process [36,[39][40][41]. A study conducted in rabbits showed that topical zinc oxide accelerates wound contraction [42], while in burn treatment it increases reepithelization rate and dermis maturation, decreasing wound colonization, along with scar thickness [43]. The topical treatment with zinc gluconate healed similar results and presented a similar bacteria load when compared with other topical treatments [44]. ...
Skin repair encompasses epidermal barrier repair and wound healing which involves multiple cellular and molecular stages. Therefore, many skin repair strategies have been proposed. In order to characterize the usage frequency of skin repair ingredients in cosmetics, medicines, and medical devices, commercialized in Portuguese pharmacies and parapharmacies, a comprehensive analysis of the products’ composition was performed. A total of 120 cosmetic products, collected from national pharmacies online platforms, 21 topical medicines, and 46 medical devices, collected from INFARMED database, were included in the study, revealing the top 10 most used skin repair ingredients in these categories. A critical review regarding the effectiveness of the top ingredients was performed and an in-depth analysis focused on the top three skin repair ingredients pursued. Results demonstrated that top three most used cosmetic ingredients were metal salts and oxides (78.3%), vitamin E and its derivatives (54.2%), and Centella asiatica (L.) Urb. extract and actives (35.8%). Regarding medicines, metal salts and oxides were also the most used (47.4%) followed by vitamin B5 and derivatives (23.8%), and vitamin A and derivatives (26.3%). Silicones and derivatives were the most common skin repair ingredients in medical devices (33%), followed by petrolatum and derivatives (22%) and alginate (15%). This work provides an overview of the most used skin repair ingredients, highlighting their different mechanisms of action, aiming to provide an up-to-date tool to support health professionals’ decisions.
... 36,46 Several studies have shown that PRP has antibacterial activity against Candida albicans, Cryptococcus neoformans, Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), 47 but it has no effect on some bacteria, including Klebsiella pneumoniae (K. pneumonia), Enterococcus faecalis (E. ...
Wound healing is a complex process in tissue regeneration through which the body responds to the dissipated cells as a result of any kind of severe injury. Diabetic and non‐healing wounds are considered an unmet clinical need. Currently, different strategic approaches are widely used in the treatment of acute and chronic wounds which include, but are not limited to, tissue transplantation, cell therapy and wound dressings, and the use of an instrument. A large number of literatures have been published on this topic; however, the most effective clinical treatment remains a challenge. The wound dressing involves the use of a scaffold, usually using biomaterials for the delivery of medication, autologous stem cells, or growth factors from the blood. Antibacterial and anti‐inflammatory drugs are also used to stop the infection as well as accelerate wound healing. With an increase in the ageing population leading to diabetes and associated cutaneous wounds, there is a great need to improve the current treatment strategies. This research critically reviews the current advancement in the therapeutic and clinical approaches for wound healing and tissue regeneration. The results of recent clinical trials suggest that the use of modern dressings and skin substitutes is the easiest, most accessible, and most cost‐effective way to treat chronic wounds with advances in materials science such as graphene as 3D scaffold and biomolecules hold significant promise. The annual market value for successful wound treatment exceeds over $50 billion US dollars, and this will encourage industries as well as academics to investigate the application of emerging smart materials for modern dressings and skin substitutes for wound therapy.
... The platelets then adhere and interact with the exposed sub-endothelial matrix components, release thrombin, and become activated to secrete granule contents to their surroundings, ultimately forming a platelet plug of fibrin at the bleeding site [16]. The entrapped activated platelets release growth factors, cytokines, chemokines, and other signaling components that attract neutrophils, macrophages, fibroblasts, and endothelial cells to propagate wound healing by facilitating subsequent phases of inflammation, proliferation, and remodeling [17]. Hence, platelets combat blood loss by adhesion, activation, and aggregation at the wound bed via augmentation of the fibrin network to initiate the wound healing process. ...
Platelet-rich plasma (PRP) is an autologous concentration of human platelets in a small volume of plasma. PRP has displayed remarkable therapeutic potential in promoting wound healing and tissue regeneration. The significance behind its use lies in the abundance of growth factors (GF) in the PRP concentrate. These factors are shown to regulate cell migration, attachment, proliferation, differentiation, and promote extracellular matrix accumulation in the wound healing process. Furthermore, its endogenous and autologous nature renders them biocompatible and biodegradable to host tissues. However, GFs suffer from a short half-life as they are susceptible to degradation by proteolytic enzymes. GFs need to be administered frequently to exert their therapeutic effects and this shortcoming has limited their clinical efficacy. To overcome such challenges, novel drug delivery systems are sought to stabilize them as well as to allow their controlled release in sufficient doses at specific sites without affecting their therapeutic efficacy. The clinical value of PRP relies on effective delivery systems which maximize their therapeutic benefit. This review shed light on the recent advancements in delivery systems for platelet derived growth factors with regards to wound healing applications. In addition, the current findings of PRP-based therapy and patent status of PRP centered drug delivery systems are also highlighted. This review hopes to stimulate ideas and encourage researchers to identify future avenues worth investigating in the field of PRP therapy.
... The blood was isolated into three layers, and the top layer was separated from the other layers by transferring to another centrifugation tube and then was centrifuged again at 3200 rpm (1600 g) for 15 minutes. 10,17 Tooth extraction process in animal models Extraction was performed under anaesthesia (ketamine and xylazine) to relieve pain. During the extraction process, the experimental animals were conditioned as comfortably as possible and were put to sleep on a support board. ...
Background: Tissue engineering technology has been used globally and proven to accelerate wound healing. This study aimed to analyse the effect of adding hydroxyapatite (HA) as a scaffold to platelet-rich fibrin (PRF) as a growth factor in accelerating the wound healing process as seen from the expression of matrix metalloproteinase-13 (MMP-13).
Methods: This research is an animal experiment conducted on 18 rabbits ( Oryctolagus cuniculus) . Rabbits were randomly divided into the following three groups of treatment: (G1) the application of PRF group, (G2) the application of PRF+HA group and (C) the control group without any application. Furthermore, each treatment group was split randomly into three groups of observation time. Periodontal tissue biopsy was performed to analyse the histopathological features that were examined on the basis of the level of MMP-13 immunoexpression.
Results: MMP-13 immunoexpression in the PRF+HA group showed better histoscore results, indicating a substantial reduction in MMP-13 values compared with other groups. The healing process was shown to increase with increasing observation time (p<0.05), and the PRF+HA group outperformed the PRF and control groups. On day 3, MMP-13 exhibited a dark brown colour of Immunohistochemistry (IHC), which indicated an increase in the expression value of MMP-13 in the early stages of healing, namely, inflammation. On day 14, light brown IHC was seen, especially in group 2, as a reference that the remodeling process had begun.
Conclusions: This study indicates that the application of HA can accelerate the socket healing process by decreasing the level of immunoexpression of MMP-13. HA is an alloplastic material that has inherent bioactive properties that support osteoconduction, which functions as a scaffold in the form of a fibrin matrix that can bind MMPs so that it can accelerate the wound healing process.
... The thickness of the granulation tissue (proliferation) and connective tissue area was measured using a micrometer video JVC Japan with four-fold magnification (14) . Evaluation of wound healing was assessed by scoring the epithelialization and the thickness of granulation tissue (15) . The epithelialization indicator used a semiquantitative evaluation of histological sections (16) , where score 1 = displacement cells (<50%), 2 = transfer of cells (≥50%), 3 = closure of the entire excision, 4 = closure of the entire excision score + keratinization. ...
This study aims to identify the effect of Hylocereus polyrhizus on the level of VEGFs and TGF-β1 in acute Wistar rat wounds. Male Albino Wistar rats (n = 54) whose (250-350 g) were divided into 3 groups (negative control, positive control, and Hylocereus polyrhizus). The animals were wounded at right and left dorsal back with an 8 mm punch biopsy. Hylocereus polyrhizus 7.5% topical cream was applied on the wound surface using a cotton bud. The VEGF and TGF-β1 were evaluated with ELISA on the 3rd, 7th, and 14th days. Analyzed using independent t-test and paired t-test (SPSS 21, Chicago Inc.). The Hylocereus polyrhizus group had higher level of VEGF and TGF-β1 compared to positive control (p = 0.011; r = -0.584) and (p = 0.000; r = 0.888), respectively, on the 14th day. It was found that there was an upward trend between the TGFβ-1 level and the tissue granulation's score (p: 0.051 and r: -0.466) as well as TGFβ-1 levels with epithelialization score (p: 0.001 and r: 0.708) in the Hylocereus polyrhizus topical group. This study has shown that Hylocereus polyrhizus can accelerate wound healing during both the inflammation and proliferation phase.
... Zinc ion possibly inhibits the growth of plaque formation and exhibits a promising potential to be used as an antibacterial agent in future dentifrices and mouth rinses [6]. Zinc containing wound dressings are commonly used for topical applications which enhance healing of chronic and acute wounds [7][8][9]. Meanwhile, there are also many evidences that zinc can provide anti-infective action in the damaged skin or tissues with little side effects [10][11][12][13][14][15]. ...
Background
In order to enhance the antibacterial activity and reduce the toxicity of Zn ²⁺ , novel complexes of Zn(II) were synthesized.
Results
A water-soluble zinc-glucose-citrate complex (ZnGC) with antibacterial activity was synthesized at pH 6.5. The structure, morphology, characterization, acute toxicity, antibacterial and antioxidant activities, and in situ intestinal absorption were investigated. The results showed that zinc ion was linked with citrate by coordinate bond while the glucose was linked with it through intermolecular hydrogen bonding. The higher the molecular weight of sugar is, the more favorable it is to inhibit the formation of zinc citrate precipitation. Compared with ZnCl 2 , ZnGC complex presented better antibacterial activity against Staphylococcus aureus ( S. aureus , Gram-positive) and Escherichia coli ( E. coli , Gram-negative).
Conclusions
The results of acute toxicity showed no obvious toxicity in this test and in situ intestinal absorption study, suggesting that ZnGC complex could be used as a potential zinc supplement for zinc deficiency.
... PRP application has promising results in acute as well as chronic injuries [46]. Recently, PRP is used in many medical fields such as regenerative medicine, dental implants and prostheses, maxillofacial surgery, plastic, orthopedics, treatment diabetic ulcer, and dry eye [13,47]. ...
Aging is a natural progressive decline in the biological function of cells. Age-related changes in the cornea can affect its ability to refract light or repair itself. Platelet-rich plasma (PRP) has a promising role in regenerative medicine and evidenced its efficacy in multiple fields, but in corneal aging has not yet been elucidated. The present work was performed to estimate the regenerative antioxidant effect of PRP on corneal aging in rats. Rats were assigned into two main groups: (GI) adult group and (GII) aged group. The adult group was divided into GIa (adult rats), GIb (adult-saline treated), and GIc (adult-PRP treated). The aged group was divided into GIIa (aged rats) and GIIb (aged, PRP treated). PRP was administered by a single subconjunctival injection. After 10 days, histological, ultrastructural, immunohistochemical, and morphometrical investigations were carried out. Examination of the corneal sections of the aged group revealed corneal epithelial thinning, shedding of the surface epithelium with loss of desmosomal junction, and irregularity in Bowman’s membrane. Disorganized widely spaced collagen bundles and neovascularization were detected in corneal stroma associated with thickening in Descemet’s membrane. Ultrastructural examination revealed shrunken hyperchromatic nuclei, swollen mitochondria, and scanty cytoplasm with a strong nuclear reaction for caspase-3 immunostaining. Moreover, antioxidant/free radicals’ imbalance was detected by the increase of malondialdehyde (MDA) level with a decrease of glutathione peroxidase (GPx) and superoxide dismutase (SOD) levels. In contrast, GIIb (aged, PRP treated) section examination revealed a restoration of the thickness of the corneal epithelial layer and Descemet’s membrane with an amendment of collagen fiber regularity that is associated with weak nuclear reaction to caspase-3 and recovery of the balance in the redox state. These findings proved the effectiveness of PRP as a promising regenerative treatment for the age-associated changes in the cornea.
1. Introduction
The cornea is the transparent anterior part of the eye that covers the iris, pupil, and the anterior chamber. Its major functions are to support the tear film and surface refractivity and to transmit light through its translucent tissue to the lens and then to the retina [1]. Corneal hydration is vital to protect the corneal epithelium from injuries and preservation of corneal transparency [2].
The cornea is formed of five distinct histological layers arranged from outer to inner, respectively, corneal epithelium, Bowman’s membrane, stroma, Descemet’s membrane, and endothelium.
The corneal epithelium (stratified squamous nonkeratinized) is one of the most sensitive and densely innervated surface tissues in the human body. It promotes the maintenance of reflex tear production and the physiologic renewal of the corneal epithelium [3]. Corneal stroma represents almost 90% of the corneal thickness [4].
The integrity of the stroma and the normal metabolism of endothelial cells are important factors to preserve corneal transparency [2]. The transparency depends on the regular spacing and uniform diameter of the collagen bundles in the stroma [5].
Moreover, Descemet’s membrane is the basement membrane of the corneal endothelium cell layer. The endothelial cell layer provides a barrier function and acts as an active water pump to keep the cornea in a constant state of dehydration [6]. People are born with a fixed number of corneal endothelial cells that gradually decreased with age [1].
Aging is a natural biological progressive process characterized by a decrease in cellular and molecular tissue functions [7]. Corneal aging produces both structural and functional changes that have a major effect on vision [8]. These changes may include keratoconus, alterations of higher order aberrations of the cornea, and a rotation of the axis of astigmatism resulting in a shift from with-the-rule to against-the-rule astigmatism [9]. Age-related alterations lead to dry eye, which in turn leads to a decrease in visual acuity, discomfort, subjacent epithelial injury, and inflammation [1].
Platelet-rich plasma (PRP) becomes an attractive way of treatment in several fields like regenerative medicine, dental and plastic surgical applications, ophthalmological surgery, trauma, and skin burns [10].
PRP is an endogenously derived therapeutic technology so it is a nontoxic and nonimmunogenic technique used to accelerate and stimulate tissue healing [11]. PRP is obtained from centrifugation for the blood sample to get cellular constitute with a platelet concentration higher than that in circulating blood [12].
PRP was found to promote tissue regeneration by enhancing cell proliferation and differentiation [13]. Platelets secrete several growth factors, including insulin-like growth factors, platelet-derived growth factor, vascular endothelial growth factor, and fibroblast growth factor [11, 14]. These growth factors promote the process of collagen formation, angiogenesis, and regeneration. Moreover, the antimicrobial ability of PRP was proved by leukocytes’ presence that lowering the risk of infection [13].
The present study is conducted to assess the efficacy of autologous platelet-rich plasma on the histopathological changes that occurred in the cornea during the aging process.
2. Materials and Methods
2.1. Animals
Thirty male albino rats of Wistar strain were used in the present study. Eighteen of the rats were aged 3-6 months old and were considered as adult rats, and the rest were aged 22-26 months old and were considered as aged rats [15]. Animals were obtained from the animal house of Research Center and Bilharzial Research Unit of Faculty of Medicine, Ain Shams University.
Rats were allowed free access to water and food and were housed in a wire cage with 12 hours day and night cycle. The animals were kept in adjusted laboratory conditions (temperature , well-ventilated wire cages). Animals were left one week for acclimatization before the start of the experiment.
2.2. Ethical Consideration
All the experiments and animal procedures were conducted following the national guidelines approved by the Committee of Animal Research Ethics (CARE), Faculty of Medicine, Ain Shams University, and following the NIH Guidelines for the Care and Use of Laboratory Animals 8th edition.
2.3. Experimental Design
In Group I, twelve adult rats were divided randomly into two groups as follows:
Ia (adult, untreated group): six adult rats were not subjected to any procedure
Ib (adult, saline-treated group): six adult rats received a single subconjunctival injection of 0.5 ml of saline then left untreated for the rest of the experiment (10 days)
Ic (adult, PRP treated group): six adult rats received a single subconjunctival injection of 0.5 ml of platelet-rich plasma (PRP) then were left untreated for the rest of the experiment (10 days) [14]
In Group II, twelve aged rats were divided randomly into two groups as follows:
IIa (aged, untreated group): six aged rats were not subjected to any procedure
IIb (aged, PRP-treated group): six aged rats received a single subconjunctival injection of 0.5 ml of platelet-rich plasma (PRP) then were left untreated for the rest of the experiment (10 days) [14]
2.4. Preparation of Platelet-Rich Plasma (PRP)
Blood samples were collected from the rats to be injected by their PRP. Rats were anesthetized by intraperitoneal injection of 10% chloral hydrate (350 mg/kg body weight) [16]. Venous blood was collected from the tail vein in acid citrate dextrose (ACD) tubes. The samples were centrifuged at 1480 rpm for 6 minutes at 20°C to sediment down red blood cells (RBCs). The supernatant plasma containing platelets was transferred into another sterile tube without anticoagulant. Secondly, the centrifuge was done at 4000 rpm for 15 minutes at 20°C to separate platelet-rich plasma (PRP) (lower 1/3rd) from platelet-poor plasma (PPP) (the upper 2/3rd) [17]. Samples were centrifuged by using Jouan ki22 Refrigerated Centrifuge (LAB EQUIP LTD, France) and processed at the Tissue Culture and Research Center in the Faculty of Medicine, Al-Azhar University, Egypt.
At the end of the experiment, all rats were euthanized by an intraperitoneal injection of phenobarbital (50 mg/kg body weight) [18]. Then, the eyes were enucleated. Some were fixed in 10% formal saline; the cornea was dissected and processed for light microscopy. Others were fixed in glutaraldehyde and processed for the ultrastructural study.
2.5. Light Microscopic Study
Specimens were fixed in 10% neutral-buffered formalin, dehydrated in graded alcohol, cleared in xylol, and embedded in paraffin. Sections of 5 μm thickness were stained with. (1)Hematoxylin and Eosin (HE) staining method [19](2)Masson trichrome staining method: for the detection of collagen fibers [19]
The slides were examined and photographed with the Lecia ICC50 camera.
2.6. Immunohistochemical Study
Five μm thick corneal sections were obtained from paraffin blocks, and the slides were dried and deparaffinized. Slides were washed in PBS. An antigen retrieval solution was applied for 10 minutes and endogenous incubation in 3% H2O2 for 10 minutes. The sections were incubated with rabbit polyclonal anticaspase-3 (Abcam, ab4051; Cambridge, UK, dilution 1 : 100) at room temperature for 90 minutes. Sections were then washed several times with PBS then incubated with secondary antibody (catalog number ab205718, Abcam, Cambridge, UK) at room temperature for 20 minutes [20]. Negative control sections were performed with the same procedure, but the primary antibody was nonimmune rabbit serum.
2.7. Ultrastructural Study
Corneal specimens from sacrificed rats were obtained and fixed in glutaraldehyde and osmium tetroxide. The fixed parts were dehydrated and embedded in Epon resin. Semithin sections, 1 μm thick was cut and stained with 1% toluidine blue and examined by a light microscope to choose the selected areas for proper orientation. Ultrathin sections (80-90 nm) were cut with a diamond knife and stained by Uranyl acetate and lead citrate [21].
The electron microscopic study was performed with a Jeol 1010 Transmission Electron Microscope (Japan) at the Regional Center for Mycology and Biotechnology, Al-Azhar University, Egypt.
2.8. Tissue Homogenate (Determination of Redox Status in the Cornea)
The tissue samples were homogenized in cold phosphate buffered saline (PBS; 10% ) using a tissue homogenizer. The homogenate was centrifuged at 10,000 rpm for 20 min at 4°C, and the supernatant was collected.
2.8.1. Malondialdehyde (MDA) Level
It is the indicator of lipid peroxidation (Colorimetric/Fluorometric Assay Kit, Catalog # K739-100, BioVision, USA). 10 mg of the sample tissue was blended with 150 μl dH2O, 3 μl BHT, and 1 vol of 2 N perchloric acid, vortexing then centrifuged to remove precipitated protein for 10 min (4000 rpm).
2.8.2. Glutathione Peroxidase Activity (GPx)
Glutathione peroxidase family of enzymes plays an important role in the protection from oxidative damage (Colorimetric Assay Kit, Catalog #K762-100; 100 reactions; Store kit at –20°C). 0.1 g tissue sample was homogenized then centrifuge for 15 min.
2.8.3. Superoxide Dismutase (SOD)
It is a group of enzymes that catalyze the superoxide radicals to hydrogen peroxide thus providing cellular defense against reactive oxygen species (Colorimetric Assay Kit, Catalog #K335-100; Store kit at –4°C). Tissue samples were washed by PBS then centrifuged at 500 rpm for 5 min.
All tissue homogenate samples were processed at Tissue Culture and Research Center, Histology Department, Al-Azhar University.
2.9. Morphometric Study
Images were analyzed using computer-based software, the image analyzer Leica (Q 500 MC program, Wetzlar, Germany) at Histology Department, Faculty of Medicine, Al-Azhar University, Egypt. Six different nonoverlapping randomly selected fields obtained from different animals from the same group were used to measure: (1)The thickness of the corneal epithelium in HE sections(2)The thickness of Descemet’s membrane in HE sections(3)Area of the percentage of caspase-3 positive cells in immunohistochemically stained sections
2.10. Statistical Analysis
The obtained data were statistically analyzed using the SPSS statistical package (IBM Corporation, New York, USA), and data are presented as (SD). Statistical analysis was performed using one-way analysis of variance (ANOVA) followed by a Tukey’s post hoc multiple comparison test. The difference was considered significant at and highly statistically significant at .
3. Results
Light and electron microscopic examination of sections of the cornea from groups Ia, Ib, and Ic showed similar findings with no observable differences. Thus, they were represented as the adult group (I) in figures.
3.1. Histological Results
Examination of HE stained sections of the cornea obtained from the adult group showed the typical structure of the cornea; the corneal epithelium is the outer layer which was formed of stratified squamous nonkeratinized epithelium appeared with superficial flat squamous cells having flat nuclei, intermediate polygonal cells with rounded nuclei, and basal columnar cells with oval nuclei. The second layer is the Bowman’s membrane which was a thin homogenous layer consisting of fibrous tissue that lies beneath the corneal epithelium (Figures 1(a) and 1(b)). The avascular corneal stroma was the third layer. It contains regularly arranged bundles of collagen fibers with spindle-shaped keratocytes in between (Figures 1(a)–1(c)). The next layer the Descemet’s membrane which appeared homogenous continuous beneath the stroma and was covered by an inner single layer of flat endothelial cells which was the fifth layer (Figures 1(a) and 1(c)).
(a)
... Wounds are skin deformities characterized by the disruption of the living tissue wholesome on both physiological and anatomical levels. The strategy of healing of wounds is overseen by a gathering of procedures, including inflammation, coagulation, granulation tissue development, epithelization, and tissue redesign (Abdullah et al. 2019;Wasef et al. 2019). Cytokines and growth factors mediate the procedure of injured tissue curative biotic which supports and strengthens the principal cellular activities essential for healing (Tatar et al. 2017). ...
... Also, to induce the injured tissue curing, there are different locally active factors of growth and clotting factors, such as transforming growth factor-α (TGF-α), platelet-derived growth factor (PDGF), insulin-like growth factor (IGF), growth factor from the vascular endothelial, and growth factor from fibroblast (Jee et al. 2016;Tatar et al. 2017). Blood platelets release fibrin, vitronectin, and fibronectin to make a holding matrix for the epithelial tissue relocation and supply a background for connective tissue (Abdullah et al. 2019). ...
... Later, they ultimately accelerate the granulation tissue collagenation and maturation, subsequently displaying a potent wound healing effect (Cakmak et al. 2014;Tatar et al. 2017). The use of PRP and its healing potential in dermal wounds have been described in several clinical and experimental studies in humans (Dionyssiou et al. 2013) and animals (Abdullah et al. 2019;Jee et al. 2016;Lee et al. 2008;Lee et al. 2019). The dynamic sequential events of the natural healing process support the requirements of cytokines combination approaches (Monteiro et al. 2009). ...
Platelet-rich plasma (PRP) composites of various cytokines and growth factors which have the potential to activate and speed the process of wound repair. Sildenafil also is a potent stimulator of angiogenesis which favors its potential effects on wound healing in several models. Existing work planned to examine the effectiveness of topical application of PRP and/or sildenafil citrate hydrogel (SCH) in a non-splinted excision skin wound model. Adult male rats were allocated into control, PRP, SCH, and PRP/SCH groups. On the 7th and 14th days, blood and tissue samples were collected for hematobiochemical, histopathological, and immunohistochemistry analyses. PRP and/or SCH topical treatments caused an enhancement of wound healing parameters, including a rapid switch from inflammatory phase to connective tissue stage evident by less systemic hematological changes and decreased values of proinflammatory cytokines (IL-6, TNF-α, and IL-1β) and C-reactive protein (CRP) on the 7th or 14th days post-wounding. Also, tissue hydroxyproline, collagen, nitrite, and total protein contents were higher in therapeutically handled wounded rats. Histologically, PRP- and/or SCH-treated wounded rats exhibited less necrosis, inflammation, and fibrin with a higher level of granulation tissue formation on the 7th day post-wounding and abundant collagen remodeling, epithelization, and vascularization on the 14th day relative to control. Interestingly, combined PRP and SCH treatment was more efficient in wound healing scoring with less inflammation, more collagen remodeling, and more epithelization. Our findings confirm the effectiveness of PRP and/or SCH as a topical wound healing treatment, with better skin wound healing with their combination.
