Role of stem cells in the management of chronic wounds

The Combination of Stromal Vascular Fraction Cells and Platelet-Rich Plasma Mediates the Inflammatory Process in Deep Dermal Burn Injury

The combination of platelet-rich plasma (PRP) and stromal vascular fraction cells (SVFs) was beneficial in accelerating wound healing. This study aims to assess the effect of this combination in balancing the inflammatory process to accelerate burn healing. Thirty eligible Wistar rats were used in this study to establish a deep dermal degree burn wound model. They were randomly divided into four groups: locally injected with the combination of SVFs and PRP (n=9), vaseline (n=9), placebo (n=9), and healthy Wistar rats group (n=3), as treatment group, positive control group, negative control group and healthy control group, respectively. The burn wound tissue was excised from three separated sacrificed rats (8, 24 and 48 hours) to examine polymorphonuclear (PMN) and lymphocyte counts through the standard hematoxylin-eosin procedure and for cyclooxygenase2 (COX-2) expression through the immunohistochemical procedure. The highest PMN, lymphocyte cell count, and COX 2 expression were found at 8 hours in the local injection with the PRP combination SVF group (28,555±11,237, 8,111±3,218, and 4,666±2,309, respectively, p <0.05 except for COX 2). The regression analysis results showed that local injection of a combination of PRP and SVF could reduce PMN cells by 1.068 times, lymphocytes by 1.786 times, and COX 2 by 1.853 times greater than topical application with vaseline. The combined injection of PRP and SVF effectively heals deep burns by acutely increasing the PMN cell and lymphocyte count, and COX 2 expression. Conversely, the treatment decreased the PMN cell and lymphocyte count but not the COX 2 expression in the sub-acute phase of wound healing.

Multifunctional and Smart Wound Dressings—A Review on Recent Research Advancements in Skin Regenerative Medicine

The healing of wounds is a dynamic function that necessitates coordination among multiple cell types and an optimal extracellular milieu. Much of the research focused on finding new techniques to improve and manage dermal injuries, chronic injuries, burn injuries, and sepsis, which are frequent medical concerns. A new research strategy involves developing multifunctional dressings to aid innate healing and combat numerous issues that trouble incompletely healed injuries, such as extreme inflammation, ischemic damage, scarring, and wound infection. Natural origin-based compounds offer distinct characteristics, such as excellent biocompatibility, cost-effectiveness, and low toxicity. Researchers have developed biopolymer-based wound dressings with drugs, biomacromolecules, and cells that are cytocompatible, hemostatic, initiate skin rejuvenation and rapid healing, and possess anti-inflammatory and antimicrobial activity. The main goal would be to mimic characteristics of fetal tissue regeneration in the adult healing phase, including complete hair and glandular restoration without delay or scarring. Emerging treatments based on biomaterials, nanoparticles, and biomimetic proteases have the keys to improving wound care and will be a vital addition to the therapeutic toolkit for slow-healing wounds. This study focuses on recent discoveries of several dressings that have undergone extensive pre-clinical development or are now undergoing fundamental research.

Stem Cell Therapy for Burns: Story so Far

Burn injuries affect approximately 11 million people annually, with fatalities amounting up to 180,000. Burn injuries constitute a global health issue associated with high morbidity and mortality. Recent years have seen advancements in regenerative medicine for burn wound healing encompassing stem cells and stem cell-derived products such as exosomes and conditioned media with promising results compared to current treatment approaches. Sources of stem cells used for treatment vary ranging from hair follicle stem cells, embryonic stem cells, umbilical cord stem cells, to mesenchymal stem cells, such as adipose-derived mesenchymal stem cells, bone marrow-derived mesenchymal stem cells, and even stem cells harvested from discarded burn tissue. Stem cells utilize various pathways for wound healing, such as PI3/AKT pathway, WNT-β catenin pathway, TGF-β pathway, Notch and Hedgehog signaling pathway. Due to the paracrine signaling mechanism of stem cells, exosomes and conditioned media derived from stem cells have also been utilized in burn wound therapy. As exosomes and conditioned media are cell-free therapy and contain various biomolecules that facilitate wound healing, they are gaining popularity as an alternative treatment strategy with significant improvement in outcomes. The treatment is provided either as direct injections or embedded in a natural/artificial scaffold. This paper reviews in detail the different sources of stem cells, stem cell-derived products, their efficacy in burn wound repair, associated signaling pathways and modes of delivery for wound healing.

The role of bacterial extracellular vesicles in chronic wound infections: Current knowledge and future challenges

Chronic wounds are a significant global problem with an increasing economic and patient welfare impact. How wounds move from an acute to chronic, non-healing, state is not well understood although it is likely that it is driven by a poorly regulated local inflammatory state. Opportunistic pathogens such as Staphylococcus aureus and Pseudomonas aeruginosa are well known to stimulate a pro-inflammatory response and so their presence may further drive chronicity. Studies have demonstrated that host cell extracellular vesicles (hEVs), in particular exosomes, have multiple roles in both increasing and decreasing chronicity within wounds; however, the role of bacterial extracellular vesicles (bEVs) is still poorly understood. The aim of this review is to evaluate bEV biogenesis and function within chronic wound relevant bacterial species to determine what, if any, role bEVs may have in driving wound chronicity. We determine that bEVs drive chronicity by both increasing persistence of key pathogens such as Staphylococcus aureus and Pseudomonas aeruginosa and stimulating a pro-inflammatory response by the host. Data also suggest that both bEVs and hEVs show therapeutic promise, providing vaccine candidates, decoy targets for bacterial toxins or modulating the bacterial species within chronic wound biofilms. Caution should, however, be used when interpreting findings to date as the bEV field is still in its infancy and as such lacks consistency in bEV isolation and characterization. It is of primary importance that this is addressed, allowing meaningful conclusions to be drawn and increasing reproducibility within the field.

The potential therapeutic effect of adipose-derived mesenchymal stem cells in the treatment of cutaneous leishmaniasis caused by L. major in BALB/c mice

Leishmaniasis is one of the most neglected tropical infectious diseases in the world. The emergence of drug resistance and toxicity and the high cost of the available drugs with a lack of new anti-leishmanial drugs highlight the need to search for newer therapies with anti-leishmanial activities. Due to the mesenchymal stem cell (MSC) immunomodulatory capacity, they have been applied in a wide variety of disorders. In this study, the potential effects of adipose-derived MSC (AD-MSCs) therapy and its combination with glucantime were evaluated in a murine model of cutaneous leishmaniasis induced by L. major. The results showed that AD-MSCs improved wound healing and decreased parasite burden. The real-time PCR results obtained from mice treated with AD-MSCs showed that IL-12 and TNF-α genes were upregulated. IL-10, arginase, and FOXP3 genes were downregulated whereas no differences in expression of the IL-4 gene were found. Overall, it seems that AD-MSCs therapy enhances Th1 immune response in L. major infected BALB/c mice. Unexpectedly, our results showed that the association of glucantime to AD-MSCs treatments did not lead to an increment in the anti-leishmanial activity.

Stem Cells: A Golden Therapy for Diabetic Wounds

Diabetes mellitus is the 7th leading cause of death worldwide. Diabetes can affect the organ systems and lead to serious complications, majorly categorized as macrovascular complications, microvascular complications, and diabetic wounds. Foot ulcer develops in 15-25% diabetic patients. In diabetic wound, there is an impairment in growth factor, neuropeptide, matrix metalloproteinases, angiogenesis, and immune system. Many approaches are being experimented to manage this major complication of diabetic foot, but unfortunately with lower success rate. Stem cell is an upcoming field which is being explored in the world of diabetes. Hence, this review is designed to understand the basic pathogenesis and complications of types of diabetes and the role of stem cells in a diabetic wound and the benefits related to it.

Application of Amniotic Stem Cells on an Acellular Dermal Matrix Scaffold in a Burned Patient: A Case Report

BACKGROUND

Advances in science have allowed newly created medicinal products based on gene therapy, somatic cell therapy, and tissue engineering to be used in the treatment of human diseases. December 2008 legislation aims to ensure they are both safe for patients and available throughout the European Union. Amniotic stem cells are designated by the European Medicines Agency Committee for Advanced Therapies as an advanced therapy medicinal product; therefore, production must be in accordance with Regulation (EC) No. 1394/2007 of the European Council of 13 November 2007 on advanced therapy medicinal products.

OBJECTIVES

This article details preliminary results of innovative amniotic stem cell transplant (supported by an acellular dermal matrix [ADM] produced in-house with Suprathel wound and burn dressing) in a burn patient and compares them with results in a patient treated with allogeneic skin.

MATERIAL AND METHODS

Amniotic stem cells were applied to a 40-year-old patient with IIb°/III° thermal burns of 36% of total body surface area and III°/IV° of 1%. Wound healing was assessed by histologic examination and the Bates-Jensen scale. Reduction in pain perception was verified by 10-point visual analog scale. Hospitalization time was compared to length of stay for patients treated with standard therapy.

RESULTS

The patient was discharged from hospital on the 12th day after surgery with complete wound healing (almost 2 times shorter than the control).

CONCLUSIONS

The use of amniotic stem cells and ADM may be the optimal method for burn treatment.

Wound Healing and the Use of Medicinal Plants

Cutaneous wound healing is the process by which skin repairs itself. It is generally accepted that cutaneous wound healing can be divided into 4 phases: haemostasis, inflammation, proliferation, and remodelling. In humans, keratinocytes re-form a functional epidermis (reepithelialization) as rapidly as possible, closing the wound and reestablishing tissue homeostasis. Dermal fibroblasts migrate into the wound bed and proliferate, creating “granulation tissue” rich in extracellular matrix proteins and supporting the growth of new blood vessels. Ultimately, this is remodelled over an extended period, returning the injured tissue to a state similar to that before injury. Dysregulation in any phase of the wound healing cascade delays healing and may result in various skin pathologies, including nonhealing, or chronic ulceration. Indigenous and traditional medicines make extensive use of natural products and derivatives of natural products and provide more than half of all medicines consumed today throughout the world. Recognising the important role traditional medicine continues to play, we have undertaken an extensive survey of literature reporting the use of medical plants and plant-based products for cutaneous wounds. We describe the active ingredients, bioactivities, clinical uses, formulations, methods of preparation, and clinical value of 36 medical plant species. Several species stand out, including Centella asiatica, Curcuma longa, and Paeonia suffruticosa, which are popular wound healing products used by several cultures and ethnic groups. The popularity and evidence of continued use clearly indicates that there are still lessons to be learned from traditional practices. Hidden in the myriad of natural products and derivatives from natural products are undescribed reagents, unexplored combinations, and adjunct compounds that could have a place in the contemporary therapeutic inventory.

Wound healing and fibrosis: current stem cell therapies

Scarring is a result of the wound healing response and causes tissue dysfunction after injury. This process is readily evident in the skin, but also occurs internally across organ systems in the form of fibrosis. Stem cells are crucial to the innate tissue healing response and, as such, present a possible modality to therapeutically promote regenerative healing while minimizing scaring. In this review, the cellular basis of scaring and fibrosis is examined. Current stem cell therapies under exploration for skin wound healing and internal organ fibrosis are discussed. While most therapeutic approaches rely on the direct application of progenitor-type cells to injured tissue to promote healing, novel strategies to manipulate the scarring response are also presented. As our understanding of developmental and stem cell biology continues to increase, therapies to encourage regeneration of healthy functional tissue after damage secondary to injury or disease will continue to expand.

Amniotic cells share clusters of differentiation of fibroblasts and keratinocytes, influencing their ability to proliferate and aid in wound healing while impairing their angiogenesis capability

An alternative to cultured skin cell grafts usage in burn treatment is the graft of allogenic stem cells. We verified whether amniotic stem cells are better than the present therapeutic standard: grafts of autologous keratinocytes and fibroblasts along with autologous adipose-derived stem cells, and whether amniotic stem cells can support the growth of autologous keratinocytes and fibroblasts in the culture. The study was performed on the material from 18 amnia. Skin cells were obtained from 3 patients. In order to assess the influence of stem cells on keratinocytes and fibroblasts, the following experiments were performed: impact on viability and cell cycle, wound healing capability, angiogenesis capability, influence on the proliferation speed and capability to differentiate into skin cells. We demonstrated that human amniotic membrane-derived mesenchymal stem cells (hAMMSCs) share amniotic proteins with skin cells. Amniotic stem cells may replace skin fibroblasts in grafts due to the close similarity in their surface antigens, with significantly larger proliferative potential and ability to stimulate wound healing. It was shown that adding amniotic cells to both keratinocytes and fibroblast cultures accelerates directional migration by ≥ 40%. We confirmed in this study the influence of amniotic cells on the proliferation and cell cycle of fibroblasts and keratinocytes. Amniotic stem cells can be successfully used not only as a first choice graft but also to replace 3T3 line cells, supporting the proliferation of the cells during the culturing, as well as a supplementary graft supporting an autologous graft of keratinocytes and fibroblasts.

Adipose-derived stem cells for treatment of chronic ulcers: current status

Chronic ulcers remain a difficult challenge in healthcare systems. While treatment options are limited, stem cells may be a novel alternative. Adipose-derived stem cells (ADSC) have become increasingly popular compared with bone marrow-derived stem cells as they are far easier to harvest. To summarize the current status of treating chronic ulcers with ADSC, this systematic review includes all clinical trials on the subject from PubMed and EmBase, as well as all registered clinical trials on ClinicalTrials.Gov. A total of nine clinical trials and fourteen registered trials were included. The studies were significantly different in terms of study design and patient population, and the overall quality of the studies was low to moderate. Despite the overall low study quality and the significant differences between the studies, some conclusions were consistent: ADSCs are safe, improve the healing of chronic ulcers, and reduce pain. As these results are consistent despite the shortcomings of the studies, they appear to highlight the efficacy of ADSCs in the treatment of chronic ulcers. Larger numbers of higher quality studies are needed to determine the precise role of ADSCs in treating chronic leg ulcers.

The Isolation and Production of the Ready-to-Use Product (the Amniotic Stem Cell Culture) in Accordance with Good Manufacturing Practice Regulations

According to the Committee for Advanced Therapies, amniotic stem cells were classified as an advanced therapy medicinal product. This work aims to standardize the isolation of amniotic stem cells and the selection of the optimal time of transplantation and cell application methods in burn patients according to the guidelines of the Good Manufacturing Practice. The placenta used in the study was sourced during a Cesarean section. The remnants of the amnion preparation were placed in a sterile container and transferred to a class B environment, where the primary cultures began. The highest average number of cells was obtained by tissue homogenization and culture growth on the AmnioGrow medium. The isolation of the pure monoculture should be performed using the antibodies against CD105. On the basis of an analysis of population doubling, the aging of a population, the cells' viability, and the severity of injury, the cells should be used between passages 3 and 6. Significant differences were found in the number and viability of cells that were transferred as a full sheet, depending on the transfer method. To sum up, amniotic cells are a promising source in the treatment of burns and can be used as a hospital exemption.

The role of adult tissue-derived stem cells in chronic leg ulcers: a systematic review focused on tissue regeneration medicine

Wound healing is an articulated process that can be impaired in different steps in chronic wounds. Chronic leg ulcers are a special type of non-healing wounds that represent an important cause of morbidity and public cost in western countries. Because of their common recurrence after conventional managements and increasing prevalence due to an ageing population, newer approaches are needed. Over the last decade, the research has been focused on innovative treatment strategies, including stem-cell-based therapies. After the initial interest in embryonic pluripotent cells, several different types of adult stem cells have been studied because of ethical issues. Specific types of adult stem cells have shown a high potentiality in tissue healing, in both in vitro and in vivo studies. Aim of this review is to clearly report the newest insights on tissue regeneration medicine, with particular regard for chronic leg ulcers.

Cadaveric bone marrow mesenchymal stem cells: first experience treating a patient with large severe burns

BACKGROUND

In January 2005, Rasulov et al. originally published "First experience in the use of bone marrow mesenchymal stem cells (MSCs) for the treatment of a patient with deep skin burns". Here, we present the first ever treated patient with cadaveric bone marrow mesenchymal stem cells (CMSCs) in the history of Medicine.

METHODS

A young man, who severely burned 60 % of his total body surface with 30 % of full-thickness burns while working with a grass trimmer that exploded, was involved in the study. MSCs were obtained from the bone marrow of a cadaver donor in a routine procurement procedure of CUCAIBA, the Province of Buenos Aires, Argentina, Ministry of Health, Transplantation Agency, cultured, expanded, and applied on the burned surfaces using a fibrin spray after early escharotomy.

RESULTS

So far, our preliminary experience and our early results have been very impressive showing an outstanding safety data as well as some impressive good results in the use of CMSCs.

CONCLUSIONS

Based on all this, we think that improvements in the use of stem cells for burns might be possible in the near future and a lot of time as well as many lives could be saved by many other research teams all over the world. CMSCs will probably be a real scientific opportunity in Regenerative Medicine as well as in Transplantation.

A Comparative Study of Honey and Phenytoin Dressings for Chronic Wounds

Chronic wounds are a common problem faced by health care professionals, both in the community and in the hospital setting. The aim of this study was to evaluate the use of honey and phenytoin with respect to the process of wound healing, eradication of infection, pain relief and hospital stay. The study included 150 patients, 3 groups of 50 each (group A, honey dressing; group B, phenytoin dressing; group C, saline dressing). The appearance of granulation tissue was faster with significant wound area reduction after 3 weeks in groups A and B compared to group C. Eradication of infection was evident earlier in the honey- and phenytoin-treated groups along with significant pain relief as compared to that of group C. The outcomes of the use of honey and phenytoin as wound dressings are beneficial and comparable. Honey provides quicker pain relief and removes malodour more effectively.

Treatment of non-healing sternum wound after open-heart surgery with allogenic platelet-rich plasma and fibrin glue-preliminary outcomes

Introduction:

Non-healing wound in the sternal region after coronary arteries bypass graft surgery is a serious complication. For healing a chronic wound, several novel approaches have been proposed recently such as using bone marrow stem cells, platelets and fibrin glue (PFG); but a non-invasive method is highly desirable in the first approach for treatment. The current study was undertaken to evaluate the effect of the combination of PFG in one treatment.

Materials and Methods:

We report on the treatment of six patients with life-threatening chronic sternum wounds, which caused septicemia with multi-drug resistant pathogens. The ulcers were extensively debrided initially and were measured and photographed at weekly intervals. The combination of PFG was applied topically on the wound after every 2 days.

Results:

The wounds were completely closed in five patients and significantly reduced in size in one. There was no evidence of local or systemic complications and any abnormal tissue formation, keloid or hypertrophic scarring.

Conclusions:

Our study suggests, in the first approach, PFG can be used safely in order to heal a non healing sternum wound following coronary artery bypass surgery.