Platelet-rich plasma (PRP) promotes fetal mesenchymal stem/stromal cell migration and wound healing process

Combined treatment of umbilical cord Wharton's jelly-derived mesenchymal stem cells and platelet-rich plasma for a surgical patient with hospital-acquired pressure ulcer: a case report and literature review

Hospital-acquired pressure ulcers (HAPUs) are still an important worldwide issue related to the safety and quality of patient care, which are among the top five adverse events reported. Patients who develop HAPUs have longer stays in the hospital than necessary, are at a greater risk of infections, and are more likely to die. Surgical patients are prone to developing PUs because they often remain immobile for extended periods of time, and their surgical procedures may limit the flow of blood oxygen and nutrition and lead to a decrease in muscle tone. Mesenchymal stem cells (MSCs) represent an attractive stem cell source for tissue regeneration in clinical applications, which have been demonstrated to improve wound healing through re-epithelialization, increased angiogenesis, and granulation tissue formation. Here, we present the case of an emergency surgical patient who developed an ulcer on the right heel during hospitalization. The human umbilical cord Wharton's jelly-derived MSCs (WJ-MSCs) re-suspended in platelet-rich plasma (PRP) were injected into ulcer margins. Four days after the WJ-MSC application, the patient showed progressive healing of the PU. From days 4 to 33, granulation tissue formation and re-epithelialization were clearly observed. The ulcer was almost healed completely on day 47, and the pain in the patient's wound area also decreased. Thus, intradermal transplantation of WJ-MSCs and PRP was safe and effective for treatment in patients with pressure ulcers. WJ-MSCs, together with PRP, may offer a promising treatment option for wound healing.

The Benefits of Using Platelet-rich Plasma with Dermal Substitutes for Extremity Posttraumatic Skin Defects: A Short-term Outcome

Background

Skin injuries are very common. Skin grafting is an ongoing wound management procedure. The artificial dermis, PELNAC, has been considered in the treatment of several acute and chronic skin injuries. Platelet-rich plasma (PRP) is blood plasma with a platelet count higher than the baseline. It is presumed to act in a synergetic pattern to promote the healing of wounds. This study was conducted to assess the potential benefit of adding PRP to PELNAC as adjuvant therapy in treating posttraumatic skin.

Methods

In this study, adult patients who were admitted to the hospital with extremity traumatic skin and soft tissue defects with exposed bare bone, exposed tendons, or exposed cartilage in the period between October 2019 and March 2021 were allocated to either being managed with dermal substitute (PELNAC) together with PRP (group I) or PELNAC alone (group II).

Results

Patients in group I showed a higher mean graft take rate and a lower mean time for neovascularization of the acellular dermal matrix, with a statistically highly significant difference. The Vancouver Scar Scale values showed no significant difference in either group. The PRP-treated group showed statistically significant shorter hospital stays.

Conclusions

The addition of PRP to the treatment protocol showed better outcomes in terms of graft take rate, time for neovascularization of acellular dermal matrix, and length of hospital stay, with no side effects. The present study findings emphasize the promising outcome of PRP in addition to the standard treatment of complex wounds to achieve rapid and safe healing.

Autologous concentrated growth factor mediated accelerated bone healing in root-end microsurgery: A multicenter randomized clinical trial

Introduction

Concentrated growth factor (CGF) is a new-generation autologous platelet concentrate that promotes tissue regeneration and has anti-inflammatory properties. This randomized multicenter trial aimed to evaluate the effects of CGF on bone healing in combination with root-end microsurgery.

Methods

Healthy adult patients indicated for root-end microsurgery were randomly assigned to either the CGF or control (no CGF implantation) groups. CGF was implanted into the bone cavity after root-end filling with mineral trioxide aggregate. Clinical and periapical radiographic evaluations were conducted at 1, 3, 6, and 12 months postoperatively, with follow-up cone-beam computed tomography (CBCT) at 6 months. The lesion volume reduction rate was calculated based on data from the preoperative and follow-up CBCT images.

Results

A total of 24 patients were enrolled. The treatment success rate was 91.7% and 83.3% on 12-month periapical radiography and 6-month CBCT, respectively, without a significant difference between the two groups. The lesion volume reduction rate in the CGF group (75.6%) was significantly higher than that in the control (61.0%) group.

Conclusions

Autologous CGF in conjunction with root-end microsurgery accelerated lesion reduction as observed on CBCT. Administering autologous blood products to stimulate healing in addition to removing the source of infection appears to be a promising treatment option for root-end microsurgery.

Assessing cell migration in hydrogels: An overview of relevant materials and methods

Cell migration is essential in numerous living processes, including embryonic development, wound healing, immune responses, and cancer metastasis. From individual cells to collectively migrating epithelial sheets, the locomotion of cells is tightly regulated by multiple structural, chemical, and biological factors. However, the high complexity of this process limits the understanding of the influence of each factor. Recent advances in materials science, tissue engineering, and microtechnology have expanded the toolbox and allowed the development of biomimetic in vitro assays to investigate the mechanisms of cell migration. Particularly, three-dimensional (3D) hydrogels have demonstrated a superior ability to mimic the extracellular environment. They are therefore well suited to studying cell migration in a physiologically relevant and more straightforward manner than in vivo approaches. A myriad of synthetic and naturally derived hydrogels with heterogeneous characteristics and functional properties have been reported. The extensive portfolio of available hydrogels with different mechanical and biological properties can trigger distinct biological responses in cells affecting their locomotion dynamics in 3D. Herein, we describe the most relevant hydrogels and their associated physico-chemical characteristics typically employed to study cell migration, including established cell migration assays and tracking methods. We aim to give the reader insight into existing literature and practical details necessary for performing cell migration studies in 3D environments.

Tumor activated platelets induce vascular mimicry in mesenchymal stem cells and aid metastasis

Extent of metastasis influences activation of platelets in tumor-microenvironment. Activated platelets potentiate mesenchymal-stem-cells (MSCs) to migrate in secondary metastatic sites without participation in process of invasion. Presence of higher percentage of MSCs along with activated-platelets induces formation of vascular-mimicry (VM). The pathophysiology, VM, has already been reported in multiple types of cancer including lung, ovary, melanoma etc. and related to poor-prognosis. Interaction of MSCs with platelets in cell-to-cell contact dependent manner is essential for their migration, thereby, VM. Evidences are obtained suggesting that under influence of tumor-associated-activated-platelets, expressions of vimentin, ve-cadherin are increased, along with decrease in e-cadherin on CD105⁺ MSCs in both mRNA and protein levels that may help in formation of vessel like structure in VM. Adoptive transfer of MSCs along with tumor-activated-platelets causes greater B16 melanoma metastasis at lungs in comparison to MSCs with non-activated platelets. Presence of CD105⁺Vimentin⁺ MSCs in vessel like structure in the metastatic lung confirms the involvement of platelet-activated-MSCs in VM, thereby, in metastasis.

Lacrimal gland injection of platelet rich plasma for treatment of severe dry eye: a comparative clinical study

Background

We aimed to assess the efficacy of the injections of platelet rich plasma (PRP) for the treatment of severe dry eye disease (DED).

Results

In this retrospecitve interventional clinincal study, we included 28 eyes of 14 patients with severe DED who were diagnosed with Sjogren syndrome. Each patient received unilateral lacrimal gland injection of PRP at days 0, 30, 60 and 90 days while the other eye served as control group who received preservative free eye drops. We objectively assessed parameters at baseline, 1 month, 2 months and 3 months including ocular surface analyzer (OSA) namely; noninvasive tear breakup times (NIBUT), tear meniscus height (TMH), lipid layer thickness (LLT) in addition to the Schirmer test I, corneal fluorescein staining (CFS) and meiboscore. The mean age was 43.4 ± .7.85 years. Comparing different parameters, baseline data showed non-significant difference between injected eye group and control group. After 1 and 3 months of follow up, there were significant differences between both groups regarding NITBUT, TMH, LLT, CFS and Schirmer test, with p <  0.001 in favor of PRP group.

Conclusion

Injection of PRP in lacrimal gland is simple, safe, and effective technique in treatment of severe dry eye; proved by improvement of tear film parameters through subjective and objective assessment. Further studies are needed to standardize the technique and to confirm these results.

Innovative Treatment Strategies to Accelerate Wound Healing: Trajectory and Recent Advancements

Wound healing is highly specialized dynamic multiple phase process for the repair of damaged/injured tissues through an intricate mechanism. Any failure in the normal wound healing process results in abnormal scar formation, and chronic state which is more susceptible to infections. Chronic wounds affect patients’ quality of life along with increased morbidity and mortality and are huge financial burden to healthcare systems worldwide, and thus requires specialized biomedical intensive treatment for its management. The clinical assessment and management of chronic wounds remains challenging despite the development of various therapeutic regimens owing to its painstakingly long-term treatment requirement and complex wound healing mechanism. Various conventional approaches such as cell therapy, gene therapy, growth factor delivery, wound dressings, and skin grafts etc., are being utilized for promoting wound healing in different types of wounds. However, all these abovementioned therapies are not satisfactory for all wound types, therefore, there is an urgent demand for the development of competitive therapies. Therefore, there is a pertinent requirement to develop newer and innovative treatment modalities for multipart therapeutic regimens for chronic wounds. Recent developments in advanced wound care technology includes nanotherapeutics, stem cells therapy, bioengineered skin grafts, and 3D bioprinting-based strategies for improving therapeutic outcomes with a focus on skin regeneration with minimal side effects. The main objective of this review is to provide an updated overview of progress in therapeutic options in chronic wounds healing and management over the years using next generation innovative approaches. Herein, we have discussed the skin function and anatomy, wounds and wound healing processes, followed by conventional treatment modalities for wound healing and skin regeneration. Furthermore, various emerging and innovative strategies for promoting quality wound healing such as nanotherapeutics, stem cells therapy, 3D bioprinted skin, extracellular matrix-based approaches, platelet-rich plasma-based approaches, and cold plasma treatment therapy have been discussed with their benefits and shortcomings. Finally, challenges of these innovative strategies are reviewed with a note on future prospects.

Autologous Platelet‐Rich Plasma Drops for Evaporative Dry Eye Disease from Meibomian Gland Dysfunction: A Pilot Study

Purpose

To evaluate the effects of autologous platelet‐rich plasma (PRP) drops for evaporative dry eye (EDE) disease from meibomian gland dysfunction (MGD).

Methods

This is a retrospective, consecutive case series of 20 eyes of 10 patients with EDE from MGD treated with PRP drops from November 2020 to November 2021 at a single outpatient clinic in Ontario, Canada. PRP drops were prepared from whole blood using a two-step centrifugation method. Patients were instructed to instill these drops six times daily for 4 weeks. The Canadian Dry Eye Assessment (CDEA) questionnaire score, patient subjective assessment (PSA) score, first and average non-invasive break-up times (f/a NIBUT), tear meniscus height (TMH), bulbar redness (BR), and meibograph grade (MG) were measured before and after the treatment course.

Results

Significant improvements in dry eye symptoms and tear film parameters were observed. Dry eye symptoms significantly improved as per the CDEA (mean difference (MD) = −5.45, 95% confidence interval (CI) = [−7.9, −3.1], p<0.001) and PSA (MD = −2.6, 95% CI = [−3.9, −1.2], p<0.001). There were significant improvements in tear film parameters including fNIBUT (MD = 3.85s, 95% CI = [1.2, 6.8], p=0.006), aNIBUT (MD = −6.81s, 95% CI = [5.7, 11.1], p<0.001) and TMH (MD = 0.08, 95% CI = [0.003, 0.2], p=0.045). There was an improvement in conjunctival injection as measured by BR (MD = −0.36, 95% CI = [−0.4, −0.15], p=0.373). Five eyes experienced a one-grade improvement in MG (p=0.453), and none experienced worsening in MG with treatment. No temporary or permanent adverse effects were noted.

Conclusion

Four weeks of PRP therapy resulted in significant functional improvements in dry eye symptoms and tear film quality and quantity. Improvements in conjunctival injection and microstructural improvements in meibomian glands were also observed in some eyes. Overall, PRP is a promising treatment option for patients with EDE from MGD refractory to conventional treatments.

PRP Versus Standard of Care for Venous leg Ulcers: A Systematic Review and Meta-Analysis of Prospective Comparative Studies

Venous leg ulcers (VLUs) are chronic and recalcitrant lower limb wounds that affect millions of patients annually, severely reducing their quality of life, and causing a significant burden on the health care system. Recently, Platelet rich plasma (PRP) has been used to improve healing of VLUs. This systematic review aimed at evaluating the effectiveness of PRP versus the standard of care commonly used to treat VLUs. Ten prospective studies (8 randomized) met the inclusion criteria comprising 451 patients with 527 VLUs. Results were as follows: a) the weighted Odds Ratio (OR) of the mean healing rate was 2.84 (95% CI = 1.160 to 5.056, I2 = 41.4%, p = 0.0004), b) the mean healed ulcer areas were 79.2 ± 19% for the PRP group and 51.7 ± 36% for the control group (p = 0.007) in favor of the PRP group, and c) the weighted infection OR showed no significant difference between both groups. Additionally, negative correlations were found between healing rate and duration of VLUs and initial size of the ulcers. This meta-analysis demonstrated significant beneficial effects of PRP versus standard of care on healing rate, reduction in surface, and reduction in healing time of VLUs. Infection and other complications were similar to standard of care. Therefore, our analytical data would support the use of PRP as a safe and effective treatment for VLUs.

Insight into Factors Influencing Wound Healing Using Phosphorylated Cellulose-Filled-Chitosan Nanocomposite Films

Marine polysaccharides are believed to be promising wound-dressing nanomaterials because of their biocompatibility, antibacterial and hemostatic activity, and ability to easily shape into transparent films, hydrogels, and porous foams that can provide a moist micro-environment and adsorb exudates. Current efforts are firmly focused on the preparation of novel polysaccharide-derived nanomaterials functionalized with chemical objects to meet the mechanical and biological requirements of ideal wound healing systems. In this contribution, we investigated the characteristics of six different cellulose-filled chitosan transparent films as potential factors that could help to accelerate wound healing. Both microcrystalline and nano-sized cellulose, as well as native and phosphorylated cellulose, were used as fillers to simultaneously elucidate the roles of size and functionalization. The assessment of their influences on hemostatic properties indicated that the tested nanocomposites shorten clotting times by affecting both the extrinsic and intrinsic pathways of the blood coagulation system. We also showed that all biocomposites have antioxidant capacity. Moreover, the cytotoxicity and genotoxicity of the materials against two cell lines, human BJ fibroblasts and human KERTr keratinocytes, was investigated. The nature of the cellulose used as a filler was found to influence their cytotoxicity at a relatively low level. Potential mechanisms of cytotoxicity were also investigated; only one (phosphorylated microcellulose-filled chitosan films) of the compounds tested produced reactive oxygen species (ROS) to a small extent, and some films reduced the level of ROS, probably due to their antioxidant properties. The transmembrane mitochondrial potential was very slightly lowered. These biocompatible films showed no genotoxicity, and very importantly for wound healing, most of them significantly accelerated migration of both fibroblasts and keratinocytes.

Striae Distensae: In Vitro Study and Assessment of Combined Treatment With Sodium Ascorbate and Platelet-Rich Plasma on Fibroblasts

INTRODUCTION

Striae distensae (SD) appear clinically as parallel striae, lying perpendicular to the tension lines of the skin. SD evolve into two clinical phases, an initial inflammatory phase in which they are called "striae rubrae" (SR) and a chronic phase in which they are called striae albae (SA). Fibroblasts seem to play a key role in the pathogenesis of stretch marks. This study was aimed at describing and analyzing stretch marks-derived fibroblasts (SMF), the differences between SR- and SA-derived fibroblasts (SRF, SAF), testing two treatments in vitro (sodium ascorbate and PrP) on SAF.

MATERIAL AND METHODS

To characterize the SMF, the expression of alpha smooth muscle actin (alpha SMA) was investigated. Type I collagen expression was measured in SAF, before and after adding different PrP concentrations and sodium ascorbate in the culture medium. Results were processed through statistical analysis models using the Student's t-test.

RESULTS

A significant increase in alpha SMA (P <0.001) was observed in SRF. SAF treated with PrP and sodium ascorbate showed a resumption of their metabolic activity by an increase in collagen type I production and cell proliferation. After 24 h of incubation with PrP 1% and PrP 5% + sodium ascorbate, cell viability was increased by 140% and 151% and by 156 and 178% after 48 h, respectively, compared to the control.

CONCLUSION

Our study shows that a biologically mediated improvement in SMF metabolic activity is possible. Our promising results require further trials to be able to confirm the reproducibility of this combined treatment, particularly in vivo.

NO LEVEL ASSIGNED

This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable.

Cellular Response to Individual Components of the Platelet Concentrate

Platelet concentrates and especially their further product platelet lysate, are widely used as a replacement for cell culturing. Platelets contain a broad spectrum of growth factors and bioactive molecules that affect cellular fate. However, the cellular response to individual components of the human platelet concentrate is still unclear. The aim of this study was to observe cellular behavior according to the individual components of platelet concentrates. The bioactive molecule content was determined. The cells were supplemented with a medium containing 8% (v/v) of platelet proteins in plasma, pure platelet proteins in deionized water, and pure plasma. The results showed a higher concentration of fibrinogen, albumin, insulin growth factor I (IGF-1), keratinocyte growth factor (KGF), and hepatocyte growth factor (HGF), in the groups containing plasma. On the other hand, chemokine RANTES and platelet-derived growth factor bb (PDGF-bb), were higher in the groups containing platelet proteins. The groups containing both plasma and plasma proteins showed the most pronounced proliferation and viability of mesenchymal stem cells and fibroblasts. The platelet proteins alone were not sufficient to provide optimal cell growth and viability. A synergic effect of platelet proteins and plasma was observed. The data indicated the importance of plasma in platelet lysate for cell growth.

Injectable gelatin microspheres loaded with platelet rich plasma improve wound healing by regulating early inflammation

We investigated the potential of gelatin microspheres (GMs) loaded with platelet-rich plasma (PRP) to enhance their wound healing effect. Platelets from the PRP were immobilized onto GMs to form biomimetic bioreactor GM+PRP. The therapeutic effect of this agent was further investigated in vivo on a wound-healing model in rats. Wounds were locally injected with phosphate buffered saline (PBS), GM, PRP, and GM+PRP. Wound healing rate, vessel density, and inflammation level were measured histologically, by RT-PCR, and by Western blotting at days 3, 7, 14, and 21. Platelets on GM caused a continuous high release in both interleukin-10 and metalloproteinase-3 compared with PRP alone. Both GM+PRP and PRP successfully accelerated the wound healing process, while GM alone did not improve the wound healing process compared with the untreated control. Wounds treated with GM+PRP resulted in shorter healing period and improved dermal structure. GM+PRP improved angiogenesis in the wound by increasing expression of angiogenic factors. GM+PRP prolonged and enhanced the cytokine release profile compared with PRP. By promoting the inflammatory and angiogenic responses, GM+PRP has the potential to improve wound healing. Our findings demonstrate that GMs are an injectable carrier that enhanced the therapeutic effects of PRP.

Applications of Mesenchymal Stem Cells in Skin Regeneration and Rejuvenation

Mesenchymal stem cells (MSCs) are multipotent stem cells derived from adult stem cells. Primary MSCs can be obtained from diverse sources, including bone marrow, adipose tissue, and umbilical cord blood. Recently, MSCs have been recognized as therapeutic agents for skin regeneration and rejuvenation. The skin can be damaged by wounds, caused by cutting or breaking of the tissue, and burns. Moreover, skin aging is a process that occurs naturally but can be worsened by environmental pollution, exposure to ultraviolet radiation, alcohol consumption, tobacco use, and undernourishment. MSCs have healing capacities that can be applied in damaged and aged skin. In skin regeneration, MSCs increase cell proliferation and neovascularization, and decrease inflammation in skin injury lesions. In skin rejuvenation, MSCs lead to production of collagen and elastic fibers, inhibition of metalloproteinase activation, and promote protection from ultraviolet radiation-induced senescence. In this review, we focus on how MSCs and MSC-derived molecules improve diseased and aged skin. Additionally, we emphasize that induced pluripotent stem cell (iPSC)-derived MSCs are potentially advanced MSCs, which are suitable for cell therapy.

The effects of oyster shell/alpha-calcium sulfate hemihydrate/platelet-rich plasma/bone mesenchymal stem cells bioengineering scaffold on rat critical-sized calvarial defects

Engineering scaffolds combining natural biomineral and artificially synthesized material hold promising potential for bone tissue regeneration. We fabricated a bioengineering scaffold, oyster shell (OS) and alpha-calcium sulfate hemihydrate (α-CSH) as scaffold, platelet-rich plasma (PRP) as provider of growth factors and bone mesenchymal stem cells (BMSCs) as seed cells, and determined it could be applied as a new type of bone graft substitutes by rat calvarial defects repairing experiment in vitro and in vivo. SEM showed that the mean diameter of the pores was about 150 μm with a range of 50-200 μm, and scaffold's porosity was ~27.4% by Archimedes' Principle. In vitro, Scaffold + BMSCs + PRP group presented a higher ALP activity compared with other groups by ELISA (P < 0.05). But the expression of OC was not detectable on day 4 or 8. The MTT assay showed that the relative cell number of BMSCs+PRP group increased significantly (P < 0.05). In vivo, the smallest defect area of skull and highest volume of regenerated new bone were observed in Scaffold + PRP + BMSCs group by X-ray and Micro-CT analysis (P < 0.05). And the similar results also were observed in HE and Masson staining. The immunohistochemistry staining for osteogenic marker proteins ALP and OC showed that the most obvious positive staining was observed in Scaffold + PRP + BMSCs group (P < 0.05). The expression of inflammatory markers IL-6 and TNF-α was the lowest in control group (P < 0.05). In conclusion, a bioengineering scaffold based on OS, created by simply combining α-CSH and PRP and implanting with BMSCs, could be clinically useful and has marked advantages as a targeted, off-the-shelf, cell-loaded treatment option for the bone healing of critical-size calvarial defects.

Peptides from Animal Origin: A Systematic Review on Biological Sources and Effects on Skin Wounds

Background

Skin wounds are closely correlated with opportunistic infections and sepsis risk. Due to the need of more efficient healing drugs, animal peptides are emerging as new molecular platforms to accelerate skin wound closure and to prevent and control bacterial infection.

Aim

The aim of this study was to evaluate the preclinical evidence on the impact of animal peptides on skin wound healing. In addition, we carried out a critical analysis of the studies' methodological quality. Main Methods. This systematic review was performed according to the PRISMA guidelines, using a structured search on the PubMed-Medline, Scopus, and Web of Science platforms to retrieve studies published until August 25, 2020 at 3 : 00 pm. The studies included were limited to those that used animal models, investigated the effect of animal peptides with no association with other compounds on wound healing, and that were published in English. Bias analysis and methodological quality assessments were examined through the SYRCLE's RoB tool.

Results

Thirty studies were identified using the PRISMA workflow. In general, animal peptides were effective in accelerating skin wound healing, especially by increasing cellular proliferation, neoangiogenesis, colagenogenesis, and reepithelialization. Considering standardized methodological quality indicators, we identified a marked heterogeneity in research protocols and a high risk of bias associated with limited characterization of the experimental designs.

Conclusion

Animal peptides show a remarkable healing potential with biotechnological relevance for regenerative medicine. However, rigorous experimental approaches are still required to clearly delimit the mechanisms underlying the healing effects and the risk-benefit ratio attributed to peptide-based treatments.

Cell-Free Fat Extract Increases Dermal Thickness by Enhancing Angiogenesis and Extracellular Matrix Production in Nude Mice

BACKGROUND

Although adipose-derived stem cells (ADSCs) and nanofat exert antiaging effects on skin, they contain cellular components that have certain limitations in clinical practice. Cell-free fat extract (Ceffe) is a fraction purified from nanofat through removal of cellular components and lipid remnants that contains various growth factors.

OBJECTIVES

The purpose of this study was to evaluate the effects of Ceffe on cultured human dermal fibroblasts in vitro and on the dermis of nude mice in vivo.

METHODS

In the in vitro study, human dermal fibroblasts were cultured with Ceffe for 72 hours, followed by flow cytometry measurement of cell proliferation and cell cycle. In the in vivo study, different concentrations of Ceffe were injected into the dorsal skin of nude mice for 4 weeks. The thickness of the dermis; proliferation of cells; density of the capillary; and expressions of type I and III collagen (Col-1 and Col-3), matrix metalloproteinase-1, matrix metalloproteinase-3, tissue inhibitor of metalloproteinase-1, and tissue inhibitor of metalloproteinase-3 were measured through histologic and Western blot analyses.

RESULTS

Ceffe significantly increased cell proliferation in cultured dermal fibroblasts. In the mouse skin, Ceffe significantly increased the thickness of the dermis, number of proliferating cells, density of the capillary, and expressions of Col-1 and Col-3.

CONCLUSIONS

Ceffe increased the dermal thickness of nude mice, possibly by enhancing angiogenesis and extracellular matrix production, and can therefore be used for skin rejuvenation.

Platelet-Rich Plasma Improves the Wound Healing Potential of Mesenchymal Stem Cells through Paracrine and Metabolism Alterations

Chronic and acute nonhealing wounds represent a major public health problem, and replacement of cutaneous lesions by the newly regenerated skin is challenging. Mesenchymal stem cells (MSC) and platelet-rich plasma (PRP) were separately tested in the attempt to regenerate the lost skin. However, these treatments often remained inefficient to achieve complete wound healing. Additional studies suggested that PRP could be used in combination with MSC to improve the cell therapy efficacy for tissue repair. However, systematic studies related to the effects of PRP on MSC properties and their ability to rebuild skin barrier are lacking. We evaluated in a mouse exhibiting 4 full-thickness wounds, the skin repair ability of a treatment combining human adipose-derived MSC and human PRP by comparison to treatment with saline solution, PRP alone, or MSC alone. Wound healing in these animals was measured at day 3, day 7, and day 10. In addition, we examined in vitro and in vivo whether PRP alters in MSC their proangiogenic properties, their survival, and their proliferation. We showed that PRP improved the efficacy of engrafted MSC to replace lost skin in mice by accelerating the wound healing processes and ameliorating the elasticity of the newly regenerated skin. In addition, we found that PRP treatment stimulated in vitro, in a dose-dependent manner, the proangiogenic potential of MSC through enhanced secretion of soluble factors like VEGF and SDF-1. Moreover, PRP treatment ameliorated the survival and activated the proliferation of in vitro cultured MSC and that these effects were accompanied by an alteration of the MSC energetic metabolism including oxygen consumption rate and mitochondrial ATP production. Similar observations were found in vivo following combined administration of PRP and MSC into mouse wounds. In conclusion, our study strengthens that the use of PRP in combination with MSC might be a safe alternative to aid wound healing.

In vitro evidence supporting applications of platelet derivatives in regenerative medicine

The role of platelets in haemostasis has long been known, but understanding of these cells' involvement in wound healing/tissue repair is more recent and has given rise to a multitude of translational studies. Tissue repair processes consist of complex, regulated interactions between cells modulated by biologically active molecules, most of which are growth factors released by activated platelets: this aspect represents the rationale on which the use of platelet derivatives for clinical purposes is based. In the last years, many in vitro studies have focused on the mechanisms of action by which these growth factors affect the biological activities of cells, thus supporting tissue healing. Although limited by some drawbacks (two-dimensional in vitro monocultures cannot replicate the tissue architecture and organisation of organs or the continuous interplay between different cell types), in vitro studies do have the advantages of giving rapid results and allowing precise control of platelet concentrations and other parameters.This review offers an updated overview of the data obtained from the most recent bench-top studies focused on the effects of platelet derivatives on a wide variety of human cells, highlighting their possible impact for in vivo applications. The heterogeneity of the data obtained so far is very evident. This can be explained by the different experimental settings used in each study, which may be the cause of the variability in clinical outcomes. In fact, in vitro studies suggest that the composition of platelet derivatives and the method used for their production and activation (or not) and the platelet concentration used can have profound effects on the final results.

Platelet-rich plasma affects the proliferation of canine bone marrow-derived mesenchymal stromal cells in vitro

BACKGROUND

Reported efficacy of platelet-rich plasma (PRP) in regenerative medicine is contradictory. We validated the effects of PRP on proliferation of canine bone marrow-derived multipotent mesenchymal stromal cells (K9BMMSCs) in vitro. PRP was extracted from blood of six dogs with osteoarthritis. K9BMMSCs were established from bone marrow and characterized for CD90 and CD19 expression by immunocytochemistry. Effects of PRP concentrations on viability of matching autologous K9BMMSCs were validated using MTS assay.

RESULTS

Positive CD90 and negative CD19 expression confirmed MSC origin. PRP at 40% volume/volume concentration increased, while PRP at 80 and 100% v/v concentrations suppressed viability of tested K9BMMSCs.

CONCLUSION

PRP concentration plays an important role in K9BMMSCs viability, which could affect tissue repairs in vivo.

Long-term culture of mesenchymal stem cells impairs ATM-dependent recognition of DNA breaks and increases genetic instability

BACKGROUND

Mesenchymal stem cells (MSCs) are attracting increasing interest for cell-based therapies, making use of both their immuno-modulating and regenerative potential. For such therapeutic applications, a massive in vitro expansion of donor cells is usually necessary to furnish sufficient material for transplantation. It is not established to what extent the long-term genomic stability and potency of MSCs can be compromised as a result of this rapid ex vivo expansion. In this study, we investigated the DNA damage response and chromosomal stability (indicated by micronuclei induction) after sub-lethal doses of gamma irradiation in murine MSCs at different stages of their in vitro expansion.

METHODS

Bone-marrow-derived tri-potent MSCs were explanted from 3-month-old female FVB/N mice and expanded in vitro for up to 12 weeks. DNA damage response and repair kinetics after gamma irradiation were quantified by the induction of γH2AX/53BP1 DSB repair foci. Micronuclei were counted in post-mitotic, binucleated cells using an automated image analyzer Metafer4. Involvement of DNA damage response pathways was tested using chemical ATM and DNA-PK inhibitors.

RESULTS

Murine bone-marrow-derived MSCs in long-term expansion culture gradually lose their ability to recognize endogenous and radiation-induced DNA double-strand breaks. This impaired DNA damage response, indicated by a decrease in the number of γH2AX/53BP1 DSB repair foci, was associated with reduced ATM dependency of foci formation, a slower DNA repair kinetics, and an increased number of residual DNA double-strand breaks 7 h post irradiation. In parallel with this impaired efficiency of DNA break recognition and repair in older MSCs, chromosomal instability after mitosis increased significantly as shown by a higher number of micronuclei, both spontaneously and induced by γ-irradiation. Multifactorial regression analysis demonstrates that in vitro aging reduced DNA damage recognition in MSCs after irradiation by a multiplicative interaction with dose (p < 0.0001), whereas the increased frequency of micronuclei was caused by an additive interaction between in vitro aging and radiation dose.

CONCLUSION

The detrimental impact of long-term in vitro expansion on DNA damage response of MSCs warrants a regular monitoring of this process during the ex vivo growth of these cells to improve therapeutic safety and efficiency.

Functional secretome analysis reveals Annexin-A1 as important paracrine factor derived from fetal mesenchymal stem cells in hepatic regeneration

BACKGROUND

Human mesenchymal stem/stromal cells (MSCs) and their secreted molecules exert beneficial effects in injured tissues by promoting tissue regeneration and angiogenesis and by inhibiting inflammation and fibrosis. We have previously demonstrated that the therapeutic activity of fetal MSCs derived from amniotic fluid (AF-MSCs) and their hepatic progenitor-like cells (HPL) is mediated by paracrine effects in a mouse model of acute hepatic failure (AHF).

METHODS

Herein, we have combined proteomic profiling of the AF-MSCs and HPL cell secretome with ex vivo and in vivo functional studies to identify specific soluble factors, which underpin tissue regeneration in AHF.

FINDINGS

The anti-inflammatory molecule Annexin-A1 (ANXA1) was detected at high levels in both AF-MSC and HPL cell secretome. Further functional analyses revealed that the shRNA-mediated knock-down of ANXA1 in MSCs (shANXA1-MSCs) decreased their proliferative, clonogenic and migratory potential, as well as their ability to differentiate into HPL cells. Liver progenitors (oval cells) from AHF mice displayed reduced proliferation when cultured ex vivo in the presence of conditioned media from shANXA1-MSCs compared to control MSCs secretome. Intra-hepatic delivery of conditioned media from control MSCs but not shANXA1-MSCs reduced liver damage and circulating levels of pro-inflammatory cytokines in AHF.

INTERPRETATION

Collectively, our study uncovers secreted Annexin-A1 as a novel effector of MSCs in liver regeneration and further underscores the potential of cell-free therapeutic strategies for liver diseases. FUND: Fondation Santé, GILEAD Asklipeios Grant, Fellowships of Excellence - Siemens, IKY, Reinforcement of Postdoctoral Researchers, IKY.

Autologous platelet-rich plasma for healing chronic venous leg ulcers: Clinical efficacy and potential mechanisms

The overall quality of evidence of autologous platelet-rich plasma (PRP) for treating chronic wounds remains low. While further well-designed clinical studies are clearly required to convincingly demonstrate the efficacy of autologous PRP in improved healing of venous leg ulcers (VLUs) and other chronic wounds, there is also an increasing need to better define the underlying mechanisms of action and whether positive outcomes can be predicted based on the analysis of PRP. This brief review will discuss the current understanding of autologous PRP in VLUs and whether molecular evaluation of PRP at the time of collection could potentially be informative to clinical outcomes. Benefits of the autologous PRP treatment strategy include that PRP is easily accessible and is relatively inexpensive and safe. Better understanding of the mechanisms involved could improve treatment, enable supplementation, and/or lead to gains in product development. Analysis of PRP could also add value to future clinical trials on efficacy and potentially personalised treatment regimens.

Autologous Platelet-Rich Plasma for Nonhealing Ulcers: A Comparative Study

Purpose

The use of platelet-rich plasma (PRP) for the treatment of nonhealing ulcers is a relatively new technique. Although it seems to result in a satisfying level of healing and low complication rates, data regarding its effectiveness remain sparse. This study aims to evaluate the potential therapeutic effects of PRP on chronic nonhealing ulcers.

Materials and Methods

This was a prospectively designed study comparing outcomes between patients treated with PRP (Group A, n=15) and patients treated conventionally (Group B, n=12) for different types of nonhealing ulcers. In Group A, PRP was produced from the patients’ own peripheral blood samples and was applied on the ulcer once every week. In Group B, patients were treated conventionally, without applying PRP. The total treatment period was 5 weeks.

Results

Both groups were similar regarding age, sex, comorbidities, and time of treatment. In Group A, patients showed a nonsignificant reduction of 4.5 mm² in ulcer area (P=0.190) and a reduction of more than 1 mm in depth (P=0.0006), while Group B showed an increase of 108±80.5 mm² in ulcer area after 5 weeks (P=0.016). The healing rate (HR) in Group A was stable and positive throughout the treatment period, while HR in Group B was initially negative but became positive after the 3rd week.

Conclusion

PRP application once a week promotes the healing of chronic ulcers. It improves the ulcer’s depth and HR, although its effect on ulcer area seems to be nonsignificant. However, larger comparative series are still needed to confirm these findings.

In Vitro Scratch Assay to Demonstrate Effects of Arsenic on Skin Cell Migration

Understanding the physiologic mechanisms of wound healing has been the focus of ongoing research for many years. This research directly translates into changes in clinical standards used for treating wounds and decreasing morbidity and mortality for patients. Wound healing is a complex process that requires strategic cell and tissue interaction and function. One of the many critically important functions of wound healing is individual and collective cellular migration. Upon injury, various cells from the blood, surrounding connective, and epithelial tissues rapidly migrate to the wound site by way of chemical and/or physical stimuli. This migration response can largely dictate the outcomes and success of a healing wound. Understanding this specific cellular function is important for translational medicine that can lead to improved wound healing outcomes. Here, we describe a protocol used to better understand cellular migration as it pertains to wound healing, and how changes to the cellular environment can significantly alter this process. In this example study, dermal fibroblasts were grown in media supplemented with fetal bovine serum (FBS) as monolayer cultures in tissue culture flasks. Cells were aseptically transferred into tissue culture treated 12-well plates and grown to 100% confluence. Upon reaching confluence, the cells in the monolayer were vertically scratched using a p200 pipet tip. Arsenic diluted in culture media supplemented with FBS was added to individual wells at environmentally relevant doses ranging 0.1-10 M. Images were captured every 4 hours (h) over a 24 h period using an inverted light microscope to observe cellular migration (wound closure). Images were individually analyzed using image analysis software, and percent wound closure was calculated. Results demonstrate that arsenic slows down wound healing. This technique provides a rapid and inexpensive first screen for evaluation of the effects of contaminants on wound healing.

Platelet-rich plasma improves therapeutic effects of menstrual blood-derived stromal cells in rat model of intrauterine adhesion

Background

Intrauterine adhesion (IUA) is a major cause of female secondary infertility. We previously demonstrated that menstrual blood-derived stromal cell (MenSC) transplantation helped severe IUA patients have pregnancy and endometrium regeneration. We also initiated platelet-rich plasma (PRP) acted as a beneficial supplement in MenSC culturing and a potential endometrial receptivity regulator. Here, we investigated the therapeutic effect of combined transplantation of MenSCs with PRP in rat IUA models and the mechanisms of MenSCs in endometrium regeneration.

Methods

Rat IUA models were established by intrauterine mechanical injured. Nine days later, all rats were randomly assigned to four groups received different treatment: placebo, MenSC transplantation, PRP transplantation, and MenSCs + PRP transplantation. The traces of MenSCs were tracked with GFP label. Endometrial morphology and pathology, tissue proliferation, inflammation, pregnancy outcomes, and mechanism of MenSCs in the regeneration of endometrium were investigated.

Results

Notably, at days 9 and 18 post-treatment, MenSC transplantation significantly improved endometrial proliferation, angiogenesis, and morphology recovery and decreased collagen fibrosis and inflammation in the uterus. MenSCs had lesion chemotaxis, colonized around the endometrial glands. Gene expression of human-derived secretory protein IGF-1, SDF-1, and TSP-1 was detected in the uterus received MenSCs at day 18. The three treatments can all improve fertility in IUA rats. Moreover, gene expressions of cell proliferation, developmental processes, and other biological processes were induced in MenSC transplantation group. Hippo signaling pathway was the most significantly changed pathway, and the downstream factors CTGF, Wnt5a, and Gdf5 were significantly regulated in treatment groups. PRP enhanced these parameters through a synergistic effect.

Conclusions

In summary, MenSCs could effectively improve uterine proliferation, markedly accelerate endometrial damage repairment and promote fertility restoration in IUA rats, suggesting a paracrine restorative effect and Hippo signaling pathway stimulation. Our results indicate MenSCs, a valuable source of cells for transplantation in the treatment intrauterine adhesion. Combined with PRP, this cell therapy was more effective.

Electronic supplementary material

The online version of this article (10.1186/s13287-019-1155-7) contains supplementary material, which is available to authorized users.

Wound Healing: A Cellular Perspective

Wound healing is one of the most complex processes in the human body. It involves the spatial and temporal synchronization of a variety of cell types with distinct roles in the phases of hemostasis, inflammation, growth, re-epithelialization, and remodeling. With the evolution of single cell technologies, it has been possible to uncover phenotypic and functional heterogeneity within several of these cell types. There have also been discoveries of rare, stem cell subsets within the skin, which are unipotent in the uninjured state, but become multipotent following skin injury. Unraveling the roles of each of these cell types and their interactions with each other is important in understanding the mechanisms of normal wound closure. Changes in the microenvironment including alterations in mechanical forces, oxygen levels, chemokines, extracellular matrix and growth factor synthesis directly impact cellular recruitment and activation, leading to impaired states of wound healing. Single cell technologies can be used to decipher these cellular alterations in diseased states such as in chronic wounds and hypertrophic scarring so that effective therapeutic solutions for healing wounds can be developed.

Autologous Platelet-Rich Plasma Reduces Healing Time of Chronic Venous Leg Ulcers: A Prospective Observational Study

The study investigated whether the application of dressings with autologous platelet-rich plasma (PRP) would reduce the healing time in patients with chronic venous leg ulcers. This is a prospective observational study that included 100 patients diagnosed with lower extremity venous insufficiency complicated by ulceration of a leg or foot, who had been after angioplasty of stenotic artery. Patients were divided into two groups of 50 each: treated with PRP (study group) and treated with conventional hydrocolloid dressings (control group). We followed the wound changes at Day 10, Day 20, and Day 30 of treatment and compared them with the baseline appearance at Day 0. We evaluated the appearance, area, and depths of wounds with ultrasound. The granulation process was examined histologically to document skin formation and wound tissue neovascularization. The findings were that treatment with PRP dressings resulted in a significant progressive reduction in ulcer size, irrespective of the ulcer's initial size, compared to treatment with conventional dressings. Further, the best effect of PRP was noticed in the category of largest wounds. After a month of treatment with PRP dressings, more than 50% of all ulcers were completely healed. The young epidermis appeared together with the granulation tissue, and the formation of dermis took shape after 20 days of treatment. We conclude that the use of PRP dressings is a safe, nonsurgical adjunctive procedure for treating chronic venous leg ulcers. The potential benefit of PRP dressings over conventional ulcer treatment requires further in-depth exploration.

Novel trends in application of stem cells in skin wound healing

The latest findings indicate the huge therapeutic potential of stem cells in regenerative medicine, including the healing of chronic wounds. Main stem cell types involved in wound healing process are: epidermal and dermal stem cells, mesenchymal stem cells (MSCs), endothelial progenitor cells (EPCs) and hematopoietic stem cells (HSCs). In the therapy of chronic wounds, they can be administrated either topically or using different matrix like hydrogels, scaffolds, dermal substitutes and extracellular matrix (ECM) derivatives. Stem cells are proven to positively influence wound healing by different direct and indirect mechanisms including residing cells stimulation, biomolecules release, inflammation control and ECM remodelling. MSCs are especially worth mentioning as they can be easily derived from bone-marrow or adipose tissue. Apart from traditional approach of administering living stem cells to wounds, new trends have emerged in recent years. Good healing results are obtained using stem cell secretome alone, for example exosomes or conditioned media. There are also attempts to improve healing potential of stem cells by their co-culture with other cell types as well as by their genetic modifications or pretreatment using different chemicals or cell media. Moreover, stem cells have been tested for novel therapeutic purposes like for example acute burns and have been used in experiments on large animal models including pigs and sheep. In this review we discuss the role of stem cells in skin wound healing acceleration. In addition, we analyse possible new strategies of stem cells application in treatment of chronic wounds.

Large adipose tissue generation in a mussel-inspired bioreactor of elastic-mimetic cryogel and platelets

Soft tissue generation, especially in large tissue, is a major challenge in reconstructive surgery to treat congenital deformities, posttraumatic repair, and cancer rehabilitation. The concern is along with the donor site morbidity, donor tissue shortage, and flap necrosis. Here, we report a dissection-free adipose tissue chamber-based novel guided adipose tissue regeneration strategy in a bioreactor of elastic gelatin cryogel and polydopamine-assisted platelet immobilization intended to improve angiogenesis and generate large adipose tissue in situ. In order to have matched tissue mechanics, we used 5% gelatin cryogel as growth substrate of bioreactor. Platelets from the platelet-rich plasma were then immobilized onto the gelatin cryogel with the aid of polydopamine to form a biomimetic bioreactor (polydopamine/gelatin cryogel/platelet). Platelets on the substrate led to a sustained high release in both platelet-derived growth factor and vascular endothelial growth factor compared with non-polydopamine-assisted group. The formed bioreactor was then transferred to a tissue engineering chamber and then inserted above inguinal fat pad of rats without flap dissection. This integrate strategy significantly boomed the vessel density, stimulated cellular proliferation, and upregulated macrophage infiltration. There was a noticeable rise in the expression of dual-angiogenic growth factors (platelet-derived growth factor and vascular endothelial growth factor) in chamber fluid; host cell migration and host fibrous protein secretion coordinated with gelatin cryogel degradation. The regenerated adipose tissue volume gained threefold larger than control group (p < 0.05) with less fibrosis tissue. These results indicate that a big well-vascularized three-dimensional mature adipose tissue can be regenerated using elastic gel, polydopamine, platelets, and small fat tissue.

First data on in vitro fertilization and blastocyst formation after intraovarian injection of calcium gluconate-activated autologous platelet rich plasma

Platelets modulate clinically relevant yet incompletely understood tissue regeneration processes, and platelet rich plasma (PRP) has been previously used with some success in various non-reproductive medical contexts. Here, we extended PRP application to ovarian tissue with a view to document impact on ovarian reserve among women attending for infertility treatment. PRP was freshly isolated from patients (n= 4) with diminished ovarian reserve as determined by at least one prior IVF cycle canceled for poor follicular recruitment response or estimated by serum AMH and/or FSH, no menses for ≥1 year. Immediately following substrate isolation and activation with calcium gluconate, approximately 5 mL of autologous PRP was injected into each ovary under direct transvaginal sonogram guidance. For each study subject, AMH, FSH, and serum estradiol data were recorded at two-week intervals post-PRP and compared to baseline (pre-PRP) values. In this pilot group, mean (±SD) patient age was 42 ± 4 years with infertility duration reported as 60 ± 25 months. Following this protocol of intraovarian PRP administration, increases in serum AMH (p = .17), decreases in FSH (p < .01), or both, were observed in all cases, sufficient to permit retrieval of 5.3 ± 1.3 MII oocytes. IVF occurred 78 ± 22 (range =  59-110) days after activated PRP injection, and results appeared independent of patient age, infertility duration, baseline platelet concentration or pretreatment antral follicle count. Each patient had at least one blastocyst suitable for cryopreservation. While autologous PRP has been successfully applied therapeutically to various tissues to accelerate healing and wound repair, this is the first description of direct injection of activated PRP into the human ovary of poor prognosis IVF patients. Evidence of improved ovarian function was noted in all who received intraovarian PRP, possibly as early as two months after treatment. Additional research is needed to clarify (and enhance) which PRP components are responsible for altered ovarian function, and to identify predictive characteristics for patients most likely to benefit from this intervention.

Adipose tissue-derived extracellular fraction characterization: biological and clinical considerations in regenerative medicine

Background

Adipose tissue-derived stem cells are considered to be a promising source in the field of cell therapy and regenerative medicine. In addition to direct cell replacement using adipose tissue or purified stem cells, intercellular molecule exchange by the adipose tissue complex, a vast array of bioactive secretory factors, demonstrated beneficial effects by reducing tissue damage and stimulation of endogenous repair. However, for therapeutic purposes, the use of secretome derivatives, such as full conditioned media or purified exosomes generated in vitro, may present considerable disadvantages for cell manufacturing, storage, product safety, and their potential as a ready-to-go therapeutic product.

Methods

In this study, the effect of a liquid fraction of lipoaspirates isolated intraoperatively from 28 healthy donors was evaluated for their protective effect against oxidative stress and senescence, proliferation, and migration in vitro on normal human melanocytes, keratinocytes, and fibroblasts. Immunoenzymatic quantification of several growth factors and important signal molecules was used to define the biological profile of physiological adipose tissue secretome.

Results

Adipose tissue extracellular fraction (AT-Ex), isolated from lipoaspirate, exhibited significant potential for skin repair. AT-Ex augmented dermal and epidermal cell proliferation in a dose-dependent manner without promoting cancer cell growth. Moreover, migration of dermal fibroblasts, an important phenomenon implicated in endogenous repair, was enhanced by AT-Ex treatment. AT-Ex has a positive impact on oxidative stress damage when cells are exposed to extrinsic hostile factors and prevent a fibroblast senescence phenotype including paracrine functions associated with skin aging.

Conclusions

Collectively, our findings propose natural systems carrying the physiological balance of in-vivo produced secretome that could improve cutaneous wound healing and tissue repair. This approach, representing an innovative perspective and therapeutic strategy in regenerative medicine, could also be combined with autologous stem cell grafts to treat chronic nonhealing wounds, stable vitiligo, severe burns, and post-oncological scarring.

Electronic supplementary material

The online version of this article (10.1186/s13287-018-0956-4) contains supplementary material, which is available to authorized users.

Randomised, prospective clinical trial of platelet-rich plasma injection in the management of severe dry eye

BACKGROUND

To evaluate the effectiveness of platelet-rich plasma (PRP) injections in the treatment of severe dry eye.

METHODS

This prospective, intervention study included patients with severe dry eye who had been diagnosed with Sjogren syndrome. Patients were divided into two groups. The intervention group received PRP (n=15) injections on days 0, 30, 60 and 90, as well as hyaluronic acid five times per day. The comparison group received hyaluronic acid (n=15) five times per day. Subjects were measured at baseline and at 30, 60 and 90 days. The primary outcome measures were changes in corneal staining according to the Oxford classification, results of the Schirmer test and tear break-up time (TBUT). The secondary outcome measures were changes in the Ocular Surface Disease Index (OSDI) and treatment compliance.

RESULTS

All subjects completed the study. The intervention group showed improvements in all primary outcome measures when compared with the control group, including a reduction in corneal staining (p<0.001), increase in the mean Schirmer value from 5.6±0.7 to 9.0±1.1 mm, and an increase in TBUT from 4.0±0.4 to 6.4±0.4 s at day 90. An improvement in subjective OSDI values was also found.

CONCLUSION

PRP injection is safe and effective in improving tear parameters as well as subjective parameters, and was found to be superior to hyaluronic acid alone in the management of patients with severe dry eye. This represent a novel alternative treatment for severe dry eye.

TRIAL REGISTRATION NUMBER

NCT02257957.

The Effects of Hyperacute Serum on the Elements of the Human Subchondral Bone Marrow Niche

Mesenchymal stem cells (MSCs) are widely used in laboratory experiments as well as in human cell therapy. Their culture requires animal sera like fetal calf serum (FCS) as essential supplementation; however, animal sera pose a risk for clinical applications. Human blood derivatives, for example, platelet-rich plasma (PRP) releasates, are potential replacements of FCS; however, it is unclear which serum variant has the best effect on the given cell or tissue type. Additionally, blood derivatives are commonly used in musculoskeletal diseases like osteoarthritis (OA) or osteonecrosis as “proliferative agents” for the topical MSC pool. Hyperacute serum (HAS), a new serum derivative, has been designed to approximate the natural coagulation cascade with a single-step, additive-free preparation method. We investigated the effects of HAS on monolayer MSC cultures and in their natural niche, in 3D subchondral bone and marrow explants. Viability measurements, RT-qPCR evaluation for gene expression and flow cytometry for cell surface marker analysis were performed to compare the effects of FCS-, PRP-, or HAS-supplemented culture media. Monolayer MSCs showed significantly higher metabolic activity following 5 days' incubation in HAS, and osteoblast-specific mRNA expression was markedly increased, while cells also retained their MSC-specific cell surface markers. A similar effect was observed on bone and marrow explants, which was further confirmed with confocal microscopy analysis. Moreover, markedly higher bone marrow preservation was observed with histology in case of HAS supplementation compared to FCS. These findings indicate possible application of HAS in regenerative solutions of skeletal diseases like OA or osteonecrosis.

The effect of mesenchymal stem cells combined with platelet-rich plasma on skin wound healing

INTRODUCTION

Mesenchymal stem cells (MSCs) are multipotent stem cells that have the potential of proliferation, high self-renewal, and the potential of multilineage differentiation. The differentiation potential of the MSCs in vivo and in vitro has caused these cells to be regarded as potentially appropriate tools for wound healing. After the burn, trauma or removal of the tumor of wide wounds is developed. Although standard treatment for skin wounds is primary healing or skin grafting, they are not always practical mainly because of limited autologous skin grafting.

EVIDENCE ACQUISITIONS

Directory of Open Access Journals (DOAJ), Google Scholar, PubMed (NLM), LISTA (EBSCO), and Web of Science have been searched.

EVIDENCE SYNTHESIS

For clinical use of the MSCs in wound healing, two key issues should be taken into account: First, engineering biocompatible scaffolds clinical use of which leads to the least amount of side effects without any immunologic response and secondly, use of stem cells secretions with the least amount of clinical complications despite their high capability of healing damage.

CONCLUSION

In light of the MSCs' high capability of proliferation and multilineage differentiation as well as their significant role in modulating immunity, these cells can be used in combination with tissue engineering techniques. Moreover, the MSCs' secretions can be used in cell therapy to heal many types of wounds. The combination of MSCs and PRP aids wound healing which could potentially be used to promote wound healing.

Silencing of Profilin-1 suppresses cell adhesion and tumor growth via predicted alterations in integrin and Ca2+ signaling in T24M-based bladder cancer models

Bladder cancer (BC) is the second most common malignancy of the genitourinary system, characterized by the highest recurrence rate of all cancers. Treatment options are limited; thus a thorough understanding of the underlying molecular mechanisms is needed to guide the discovery of novel therapeutic targets. Profilins are actin binding proteins with attributed pleiotropic functions to cytoskeletal remodeling, cell adhesion, motility, even transcriptional regulation, not fully characterized yet. Earlier studies from our laboratory revealed that decreased tissue levels of Profilin-1 (PFN1) are correlated with BC progression to muscle invasive disease. Herein, we describe a comprehensive analysis of PFN1 silencing via shRNA, in vitro (by employing T24M cells) and in vivo [(with T24M xenografts in non-obese diabetic severe combined immunodeficient mice (NOD/SCID) mice]. A combination of phenotypic and molecular assays, including migration, proliferation, adhesion assays, flow cytometry and total mRNA sequencing, as well as immunohistochemistry for investigation of selected findings in human specimens were applied. A decrease in BC cell adhesion and tumor growth in vivo following PFN downregulation are observed, likely associated with the concomitant downregulation of Fibronectin receptor, Endothelin-1, and Actin polymerization. A decrease in the levels of multiple key members of the non-canonical Wnt/Ca²⁺ signaling pathway is also detected following PFN1 suppression, providing the groundwork for future studies, addressing the specific role of PFN1 in Ca²⁺ signaling, particularly in the muscle invasive disease.

Platelet Rich Plasma: New Insights for Cutaneous Wound Healing Management

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

The role of PRP and adipose tissue-derived keratinocytes on burn wound healing in diabetic rats

Introduction: Diabetic burn wounds and ulcers are significant complications of diabetic patients. The aim of this study is to investigate the use of platelet rich-plasma (PRP) and/or keratinocyte-like cells (KLCs) in diabetic thermal wound rat model and to evaluate EGF, FGF-2, TGF-β1, COL1α2, MCP-1 and VEGF-α as wound healing markers at gene expression level.

Method: In this study, we used adipose tissue as the source of mesenchymal stem cells (MSCs) and differentiated MSCs into KLCs. KLCs were characterized and transferred to the burn areas on the dorsum of streptozotocine (STZ)-induced diabetic rats. We prepared PRP from rat blood and evaluated its effect alone or in combination with KLCs. On 3^rd, 7^th, 10^th and 14^th days after treatment, wound areas were measured and biopsy samples were excised from the wound areas of the KLCs and/or PRP-treated and untreated diabetic rats to analyze gene expression levels of wound healing markers by qPCR.

Results: We observed that, wound contraction started earlier in the PRP and/or KLCs-treated groups in comparison to the control group. However, PRP and KLCs when applied in combination showed additive affect in wound healing. In all groups treated with KLCs and/or PRP, the gene expression levels of evaluated growth factors and COL1α2 increased, while MCP-1 levels decreased when compared to the untreated diabetic rats. In addition, the most prominent difference in qPCR results belongs to combined PRP and KLCs-treated group.

Conclusion: We demonstrated that applying PRP and KLCs in combination has a greater potential for treatment of diabetic burn wounds.

Comparative Effects of Platelet-Rich Plasma, Platelet Lysate, and Fetal Calf Serum on Mesenchymal Stem Cells

We studied the effects of human platelet-rich plasma and platelet lysate on proliferation, migration, and colony-forming properties of rat mesenchymal stem cells. Platelet-rich plasma and platelet lysate stimulated the proliferation, migration, and colony formation of mesenchymal stem cells. A real-time study showed that platelet-rich plasma produces the most potent stimulatory effect, while both platelet-rich plasma and platelet lysate stimulated migration of cells.

Effects of three blood derived products on equine corneal cells, an in vitro study

BACKGROUND

Despite advances in therapy of corneal ulcerative diseases in horses, a vast number of cases require surgical intervention, due to poor response to treatment. Topical application of serum has been used for many years, based on its anticollagenolytic properties and the presence of growth factors promoting corneal wound healing. However, although other blood derived products i.e. platelet rich plasma (PRP), plasma rich in growth factors (PRGF) have been widely used in equine orthopaedics and in human ophthalmology, no reports of the effects of these blood derived products exist in equine ophthalmology.

OBJECTIVES

To determine in vitro effects of PRGF and PRP on equine corneal cells compared with serum.

STUDY DESIGN

Prospective controlled cohort study.

METHODS

Blood from 35 healthy horses was used to produce serum, PRGF (Endoret^® ), and PRP (E-PET™). Limbal- and stromal cells were isolated from healthy corneas of six horses and treated with 20% serum, 20% PRGF or 20% PRP. Proliferation rates and migration capacity were analysed in single cell cultures as well as co-culture systems.

RESULTS

Cell proliferation increased with PRP treatment, remained constant in PRGF treated cells, and declined upon serum treatment over a period of 48 h. Migration capacity was significantly enhanced with PRP treatment, compared with PRGF treatment. Intact leucocytes, mainly eosinophils, were only detected in PRP.

MAIN LIMITATIONS

Due to the study design use of autologous blood products on corneal cells was not possible.

CONCLUSIONS

The results demonstrate beneficial effects of PRP on proliferation as well as migration capacity of equine corneal cells in vitro. In vivo studies are warranted to determine further beneficial effects of PRP in horses with corneal ulcers.

Umbilical Cord Blood Platelet Lysate as Serum Substitute in Expansion of Human Mesenchymal Stem Cells

Objective

The diverse clinical applications for human mesenchymal stem cells (hM- SCs) in cellular therapy and regenerative medicine warrant increased focus on developing adequate culture supplements devoid of animal-derived products. In the present study, we have investigated the feasibility of umbilical cord blood-platelet lysate (UCB-PL) as a standard substitute for fetal bovine serum (FBS) and human peripheral blood-PL (PB-PL).

Materials and Methods

In this experimental study, platelet concentrates (PC) from UCB and human PB donors were frozen, melted, and sterilized to obtain PL. Quality control included platelet cell counts, sterility testing (viral and microbial), total protein concentrations, growth factor levels, and PL stability. The effects of UCB-PL and PB-PL on hMSCs proliferation and differentiation into osteocytes, chondrocytes, and adipocytes were studied and the results compared with FBS.

Results

UCB-PL contained high levels of protein content, platelet-derived growth factor-AB (PDGF-AB), and transforming growth factor (TGF) compared to PB-PL. All growth factors were stable for at least nine months post-storage at -70˚C. hMSCs proliferation enhanced following treatment with UCB-PL. With all three supplements, hMSCs could differentiate into all three lineages.

Conclusion

PB-PL and UCB-PL both were potent in hMSCs proliferation. However, PB promoted osteoblastic differentiation and UCB-PL induced chondrogenic differentiation. Because of availability, ease of use and feasible standardization of UCB-PL, we have suggested that UCB-PL be used as an alternative to FBS and PB-PL for the cultivation and expansion of hMSCs in cellular therapy.

Use of platelet-rich plasma (PRP) in microsurgery

Platelet-rich plasma (PRP) is currently used for its property to improve tissue regeneration and wound healing. Platelet derived growth factors are involved in tissue regeneration and new vessels formation that could improve a free flap survival. Nevertheless to validate the use of regenerative medicine in microsurgery further large and robust human clinical trials are needed.

Possible mechanism underlying the association between higher hemoglobin level and hypertension in older Japanese men

AIM

Hemoglobin is reported to be positively associated with hypertension. However, the underlying mechanism of this association is unknown. Recently, bone marrow-derived CD34-positive cells have been reported to play an important role in endothelial repair in conjunction with platelets. As the association between hypertension and endothelial dysfunction is bidirectional, the influence of endothelial repair also might strongly influence the association between hemoglobin and hypertension.

METHODS

To clarify the clinical importance of the hematological parameter on endothelial maintenance in older men, we carried out a cross-sectional study of 222 Japanese men aged 60-69 years undergoing a general health checkup.

RESULTS

For participants with a lower platelet count (≤21.0/μL), hemoglobin was significantly positively associated with hypertension, but not for participants with a higher platelet count (>21.0/μL). The classical cardiovascular risk factor adjusted odds ratio of hypertension for 1-standard deviation increment of hemoglobin (1.0 g/dL) was 2.09 (95% CI: 1.26, 3.48) for participants with a lower platelet count, and 1.07 (95% CI: 0.68, 1.67) for participants with a higher platelet count. We also found that although there was no significant correlation between hemoglobin and circulating CD34-positive cells for participants with a lower platelet count (β = -0.06, P = 0.603), a significant positive correlation was seen for participants with a higher platelet count (β = 0.29, P = 0.004).

CONCLUSIONS

The positive association between hemoglobin and hypertension was limited to participants with a lower platelet count as a result of insufficient endothelial repair. These results represent an efficient tool for clarifying the mechanism of endothelial maintenance that correlates with hypertension. Geriatr Gerontol Int 2017; 17: 2586-2592.

The combination of nano-calcium sulfate/platelet rich plasma gel scaffold with BMP2 gene-modified mesenchymal stem cells promotes bone regeneration in rat critical-sized calvarial defects

BACKGROUND

Mesenchymal stem cells (MSCs) can be differentiated into an osteoblastic lineage in the presence of growth factors (GFs). Platelet-rich plasma (PRP), which can be easily isolated from whole blood, contains a large amount of GFs, and, therefore, promotes bone growth and regeneration. The main goal of this work was to develop and investigate the effect of a new sandwich-like bone scaffold which combines a nano-calcium sulfate (nCS) disc along with PRP fibrin gel (nCS/PRP) with BMP2-modified MSCs on bone repair and regeneration in rat critical-sized calvarial defects.

METHODS

We evaluated the cytotoxicity, osteogenic differentiation and mineralization effect of PRP extract on BMP2-modified MSCs and constructed a sandwich-like nCS/PRP scaffold (mimicking the nano-calcium matrix of bone and carrying multi GFs in the PRP) containing BMP2-modified MSCs. The capacity of this multifunctional bone regeneration system in promoting bone repair was assessed in vivo in a rat critical-sized (8 mm) calvarial bone defect model.

RESULTS

We developed an optimized nCS/PRP sandwich-like scaffold. Scanning electron microscopy (SEM) results showed that nCS/PRP are polyporous with an average pore diameter of 70-80 μm and the cells can survive in the nCS/PRP scaffold. PRP extract dramatically stimulated proliferation and differentiation of BMP2-modified MSCs in vitro. Our in vivo results showed that the combination of BMP2-modified MSCs and nCS/PRP scaffold dramatically increased new bone regeneration compared with the groups without PRP and/or BMP2.

CONCLUSIONS

nCS/PRP scaffolds containing BMP2-modified MSCs successfully promotes bone regeneration in critical-sized bone defects. This system could ultimately enable clinicians to better reconstruct the craniofacial bone and avoid donor site morbidity for critical-sized bone defects.

Proteomics analysis of bladder cancer invasion: Targeting EIF3D for therapeutic intervention

Patients with advanced bladder cancer have poor outcomes, indicating a need for more efficient therapeutic approaches. This study characterizes proteomic changes underlying bladder cancer invasion aiming for the better understanding of disease pathophysiology and identification of drug targets. High resolution liquid chromatography coupled to tandem mass spectrometry analysis of tissue specimens from patients with non-muscle invasive (NMIBC, stage pTa) and muscle invasive bladder cancer (MIBC, stages pT2+) was conducted. Comparative analysis identified 144 differentially expressed proteins between analyzed groups. These included proteins previously associated with bladder cancer and also additional novel such as PGRMC1, FUCA1, BROX and PSMD12, which were further confirmed by immunohistochemistry. Pathway and interactome analysis predicted strong activation in muscle invasive bladder cancer of pathways associated with protein synthesis e.g. eIF2 and mTOR signaling. Knock-down of eukaryotic translation initiation factor 3 subunit D (EIF3D) (overexpressed in muscle invasive disease) in metastatic T24M bladder cancer cells inhibited cell proliferation, migration, and colony formation in vitro and decreased tumor growth in xenograft models. By contrast, knocking down GTP-binding protein Rheb (which is upstream of EIF3D) recapitulated the effects of EIF3D knockdown in vitro, but not in vivo. Collectively, this study represents a comprehensive analysis of NMIBC and MIBC providing a resource for future studies. The results highlight EIF3D as a potential therapeutic target.

Minocycline enhances the mesenchymal stromal/stem cell pro-healing phenotype in triple antimicrobial-loaded hydrogels

Mesenchymal stromal/stem cells (MSCs) have demonstrated pro-healing properties including an anti-inflammatory cytokine profile and the promotion of angiogenesis via expression of growth factors in pre-clinical models. MSCs encapsulated in poly(ethylene glycol) diacrylate (PEGdA) and thiolated gelatin poly(ethylene glycol) (Gel-PEG-Cys) crosslinked hydrogels have led to controlled cellular presentation at wound sites with favorable wound healing outcomes. However, the therapeutic potential of MSC-loaded hydrogels may be limited by non-specific protein adsorption on the delivery matrix that could facilitate the initial adhesion of microorganisms and subsequent virulent biofilm formation. Antimicrobials loaded concurrently in the hydrogels with MSCs could reduce microbial bioburden and promote healing, but the antimicrobial effect on the MSC wound healing capacity and the antibacterial efficacy of the hydrogels is unknown. We demonstrate that minocycline specifically induces a favorable change in MSC migration capacity, proliferation, gene expression, extracellular matrix (ECM) attachment, and adhesion molecule and growth factor release with subsequent increased angiogenesis. We then demonstrate that hydrogels loaded with MSCs, minocycline, vancomycin, and linezolid can significantly decrease bacterial bioburden. Our study suggests that minocycline can serve as a dual mechanism for the regenerative capacity of MSCs and the reduction of bioburden in triple antimicrobial-loaded hydrogels.

STATEMENT OF SIGNIFICANCE

Wound healing is a complex biological process that can be hindered by bacterial infection, excessive inflammation, and inadequate microvasculature. In this study, we develop a new formulation of poly(ethylene glycol) diacrylate and thiolated gelatin poly(ethylene glycol) crosslinked hydrogels loaded with minocycline, vancomycin, linezolid, and mesenchymal stromal/stem cells that induces a favorable wound healing phenotype in mesenchymal stromal/stem cells and prevents bacterial bioburden on the hydrogel. This combinatorial approach to biomaterial development has the potential to impact wound healing for contaminated full thickness cutaneous wounds.

miR-26a Mediates Adipogenesis of Amniotic Fluid Mesenchymal Stem/Stromal Cells via PTEN, Cyclin E1, and CDK6

Recent findings indicate that microRNAs (miRNAs) are critical for the regulatory network of adipogenesis in human mesenchymal stem/stromal cells (MSCs). Fetal MSCs derived from amniotic fluid (AF-MSCs) represent a population of multipotent stem cells characterized by a wide range of differentiation properties that can be applied in cell-based therapies. In this study, miRNA microarray analysis was performed to assess miRNA expression in terminal differentiated AF-MSCs into adipocyte-like cells (AL cells). MiR-26a was identified in high expression levels in AL cells indicating a critical role in the process of adipogenesis. Overexpression of miR-26a in AF-MSCs led to significant induction of their adipogenic differentiation properties that were altered after miR-26a inhibition. We have demonstrated that miR-26a regulates adipogenesis through direct inhibition of PTEN, which in turn promotes activation of Akt pathway. Also, miR-26a modulates cell cycle during adipogenesis by interacting with Cyclin E1 and CDK6. These results point to the regulatory role of miR-26a and its target genes PTEN, Cyclin E1, and CDK6 in adipogenic differentiation of AF-MSCs, providing a basis for understanding the mechanisms of fat cell development and obesity.