scholarly journals Effect of Unloading Condition on the Healing Process and Effectiveness of Platelet Rich Plasma as a Countermeasure: Study on In Vivo and In Vitro Wound Healing Models

2020 ◽  
Vol 21 (2) ◽  
pp. 407 ◽  
Author(s):  
Francesca Cialdai ◽  
Alessandra Colciago ◽  
Desiré Pantalone ◽  
Angela Maria Rizzo ◽  
Stefania Zava ◽  
...  

Wound healing is a very complex process that allows organisms to survive injuries. It is strictly regulated by a number of biochemical and physical factors, mechanical forces included. Studying wound healing in space is interesting for two main reasons: (i) defining tools, procedures, and protocols to manage serious wounds and burns eventually occurring in future long-lasting space exploration missions, without the possibility of timely medical evacuation to Earth; (ii) understanding the role of gravity and mechanical factors in the healing process and scarring, thus contributing to unravelling the mechanisms underlying the switching between perfect regeneration and imperfect repair with scarring. In the study presented here, a new in vivo sutured wound healing model in the leech (Hirudo medicinalis) has been used to evaluate the effect of unloading conditions on the healing process and the effectiveness of platelet rich plasma (PRP) as a countermeasure. The results reveal that microgravity caused a healing delay and structural alterations in the repair tissue, which were prevented by PRP treatment. Moreover, investigating the effects of microgravity and PRP on an in vitro wound healing model, it was found that PRP is able to counteract the microgravity-induced impairment in fibroblast migration to the wound site. This could be one of the mechanisms underlying the effectiveness of PRP in preventing healing impairment in unloading conditions.

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Yan Xu ◽  
Ze Lin ◽  
Lei He ◽  
Yanzhen Qu ◽  
Liu Ouyang ◽  
...  

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.


2021 ◽  
Author(s):  
Yan Xu ◽  
Ze Lin ◽  
Lei He ◽  
Yanzhen Qu ◽  
Ouyang Liu ◽  
...  

Abstract Background: Epithelial regeneration is an essential wound healing process, and recent work suggests that different types of exosomes (Exos) can be employed to 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. Results: We found that PRP-derived exosomes (PRP-Exos) effectively promoted the in vitro proliferation, migration, and wound healing activity of human immortalized keratinocytes (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. Conclusions: PRP-Exos and USP15 represent promising tools that can promote wound healing via enhancing epithelial regeneration.


2021 ◽  
Vol 22 (8) ◽  
pp. 4087
Author(s):  
Maria Quitério ◽  
Sandra Simões ◽  
Andreia Ascenso ◽  
Manuela Carvalheiro ◽  
Ana Paula Leandro ◽  
...  

Insulin is a peptide hormone with many physiological functions, besides its use in diabetes treatment. An important role of insulin is related to the wound healing process—however, insulin itself is too sensitive to the external environment requiring the protective of a nanocarrier. Polymer-based nanoparticles can protect, deliver, and retain the protein in the target area. This study aims to produce and characterize a topical treatment for wound healing consisting of insulin-loaded poly-DL-lactide/glycolide (PLGA) nanoparticles. Insulin-loaded nanoparticles present a mean size of approximately 500 nm and neutral surface charge. Spherical shaped nanoparticles are observed by scanning electron microscopy and confirmed by atomic force microscopy. SDS-PAGE and circular dichroism analysis demonstrated that insulin preserved its integrity and secondary structure after the encapsulation process. In vitro release studies suggested a controlled release profile. Safety of the formulation was confirmed using cell lines, and cell viability was concentration and time-dependent. Preliminary safety in vivo assays also revealed promising results.


2017 ◽  
Vol 751 ◽  
pp. 581-585 ◽  
Author(s):  
Piyaporn Kampeerapappun ◽  
Pornpen Siridamrong

The objective of this study was to investigate sericin-polyurethane nanofiber cover (SUC) for wound dressing materials in a rat skin. Sericin-polyurethane blended nanofibers were fabricated by using electrospinning. The composition of 3%w/v polyurethane in ethanol and 19% w/v sericin were blended and electrospun at 15 kV, 20 cm from tip to collector with a feed rate of 6.2 ml/hr. The mats, approximately 1.5 mm thick, were sterile by gamma irradiation with a radiation dose of 15 kGy. The samples of in vitro and in vivo testing were separated into three groups; gauze, polyurethane nanofiber cover (UC), and SUC. In vitro cultured L929 cell lines were investigated with inverted microscope. It was found that cells migrated to SCU. For in vivo tests, the remaining wound in rats was measured on day 2-14 after excision. Compared to original size of wound samples, the size of the wound remained 24% for SUC, 33% for gauze, and 34% for UC at day 8. The sericin, an active agent, contained in SUC mats was about 5 µl at 1.5 ×1.5 cm. It can be concluded that sericin is non-toxic to cells and can promote wound healing process in rats.


2021 ◽  
pp. 088532822199601
Author(s):  
Linying Shi ◽  
Fang Lin ◽  
Mou Zhou ◽  
Yanhui Li ◽  
Wendan Li ◽  
...  

The ever-growing threats of bacterial infection and chronic wound healing have provoked an urgent need for novel antibacterial wound dressings. In this study, we developed a wound dressing for the treatment of infected wounds, which can reduce the inflammatory period (through the use of gentamycin sulfate (GS)) and enhance the granulation stage (through the addition of platelet-rich plasma (PRP)). Herein, the sustained antimicrobial CMC/GMs@GS/PRP wound dressings were developed by using gelatin microspheres (GMs) loading GS and PRP, covalent bonding to carboxymethyl chitosan (CMC). The prepared dressings exhibited high water uptake capability, appropriate porosity, excellent mechanical properties, sustain release of PRP and GS. Meanwhile, the wound dressing showed good biocompatibility and excellent antibacterial ability against Gram-negative and Gram-positive bacteria. Moreover, in vivo experiments further demonstrated that the prepared dressings could accelerate the healing process of E. coli and S. aureus-infected full-thickness wounds i n vivo, reepithelialization, collagen deposition and angiogenesis. In addition, the treatment of CMC/GMs@GS/PRP wound dressing could reduce bacterial count, inhibit pro-inflammatory factors (TNF-α, IL-1β and IL-6), and enhance anti-inflammatory factors (TGF-β1). The findings of this study suggested that biocompatible wound dressings with dual release of GS and PRP have great potential in the treatment of chronic and infected wounds.


Author(s):  
Gil Topman ◽  
Orna Sharabani-Yosef ◽  
Amit Gefen

A wound healing assay is simple but effective method to study cell migration in vitro. Cell migration in vitro was found to mimic migration in vivo to some extent [1,2]. In wound healing assays, a “wound” is created by either scraping or mechanically crushing cells in a monolayer, thereby forming a denuded area. Cells migrate into the denuded area to complete coverage, and thereby “heal” the wound. Micrographs at regular time intervals are captured during such experiments for analysis of the process of migration.


Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3116
Author(s):  
Thien Do ◽  
Tien Nguyen ◽  
Minh Ho ◽  
Nghi Nguyen ◽  
Thai Do ◽  
...  

(1) Background: Wounds with damages to the subcutaneous are difficult to regenerate because of the tissue damages and complications such as bacterial infection. (2) Methods: In this study, we created burn wounds on pigs and investigated the efficacy of three biomaterials: polycaprolactone-gelatin-silver membrane (PCLGelAg) and two commercial burn dressings, Aquacel® Ag and UrgoTulTM silver sulfadiazine. In vitro long-term antibacterial property and in vivo wound healing performance were investigated. Agar diffusion assays were employed to evaluate bacterial inhibition at different time intervals. Minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and time-kill assays were used to compare antibacterial strength among samples. Second-degree burn wounds in the pig model were designed to evaluate the efficiency of all dressings in supporting the wound healing process. (3) Results: The results showed that PCLGelAg membrane was the most effective in killing both Gram-positive and Gram-negative bacteria bacteria with the lowest MBC value. All three dressings (PCLGelAg, Aquacel, and UrgoTul) exhibited bactericidal effect during the first 24 h, supported wound healing as well as prevented infection and inflammation. (4) Conclusions: The results suggest that the PCLGelAg membrane is a practical solution for the treatment of severe burn injury and other infection-related skin complications.


2020 ◽  
Author(s):  
Daisuke Ito ◽  
Hiroyasu Ito ◽  
Takayasu Ideta ◽  
Ayumu Kanbe ◽  
Soranobu Ninomiya ◽  
...  

Abstract Background The skin wound healing process is regulated by various cytokines, chemokines, and growth factors. Recent reports have demonstrated that spermine/spermidine (SPD) promote wound healing through urokinase-type plasminogen activator (uPA)/uPA receptor (uPAR) signaling in vitro. Here, we investigated whether the systemic and topical administration of SPD would accelerate the skin wound-repair process in vivo.Methods A skin wound repair model was established using C57BL/6 J mice. SPD was mixed with white petrolatum for topical administration. For systemic administration, SPD mixed with drinking water was orally administered. Changes in wound size over time were calculated using digital photography.Results Systemic and topical SPD treatment significantly accelerated skin wound healing. The administration of SPD promoted the uPA/uPAR pathway in wound sites. Moreover, topical treatment with SPD enhanced the expression of IL-6 and TNF-α in wound sites. Scratch and cell proliferation assays revealed that SPD administration accelerated scratch wound closure and cell proliferation in vitro.Conclusion These results indicate that treatment with SPD promotes skin wound healing through activation of the uPA/uPAR pathway and induction of the inflammatory response in wound sites. The administration of SPD might contribute to new effective treatments to accelerate skin wound healing.


Biomedicines ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1153
Author(s):  
Verena Schneider ◽  
Daniel Kruse ◽  
Ives Bernardelli de Mattos ◽  
Saskia Zöphel ◽  
Kendra-Kathrin Tiltmann ◽  
...  

Burns affect millions every year and a model to mimic the pathophysiology of such injuries in detail is required to better understand regeneration. The current gold standard for studying burn wounds are animal models, which are under criticism due to ethical considerations and a limited predictiveness. Here, we present a three-dimensional burn model, based on an open-source model, to monitor wound healing on the epidermal level. Skin equivalents were burned, using a preheated metal cylinder. The healing process was monitored regarding histomorphology, metabolic changes, inflammatory response and reepithelialization for 14 days. During this time, the wound size decreased from 25% to 5% of the model area and the inflammatory response (IL-1β, IL-6 and IL-8) showed a comparable course to wounding and healing in vivo. Additionally, the topical application of 5% dexpanthenol enhanced tissue morphology and the number of proliferative keratinocytes in the newly formed epidermis, but did not influence the overall reepithelialization rate. In summary, the model showed a comparable healing process to in vivo, and thus, offers the opportunity to better understand the physiology of thermal burn wound healing on the keratinocyte level.


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