Topical application of hPDGF-A-modified porcine BMSC and keratinocytes loaded on acellular HAM promotes the healing of combined radiation-wound skin injury in minipigs

Mesenchymal stem cell-based therapy for burn wound healing

Burns, with their high incidence and mortality rates, have a devastating effect on patients. There are still huge challenges in the management of burns. Mesenchymal stem cells (MSCs), which have multidirectional differentiation potential, have aroused interest in exploring the capacity for treating different intractable diseases due to their strong proliferation, tissue repair, immune tolerance and paracrine abilities, among other features. Currently, several animal studies have shown that MSCs play various roles and have beneficial effects in promoting wound healing, inhibiting burn inflammation and preventing the formation of pathological scars during burn healing process. The substances MSCs secrete can act on peripheral cells and promote burn repair. According to preclinical research, MSC-based treatments can effectively improve burn wound healing and reduce pain. However, due to the small number of patients and the lack of controls, treatment plans and evaluation criteria vary widely, thus limiting the value of these clinical studies. Therefore, to better evaluate the safety and effectiveness of MSC-based burn treatments, standardization of the application scheme and evaluation criteria of MSC therapy in burn treatment is required in the future. In addition, the combination of MSC pretreatment and dressing materials are also conducive to improving the therapeutic effect of MSCs on burns. In this article, we review current animal research and clinical trials based on the use of stem cell therapy for treating burns and discuss the main challenges and coping strategies facing future clinical applications.

An update on stem cells applications in burn wound healing

Burn wounds have proven to be capable of having a long lasting devastating effects on human body. Conventional therapeutic approaches are not up to the mark as they are unable to completely heal the burn wound easily and effectively. Major pitfalls of these treatments include hypertrophic scarring, contracture and necrosis. Presence of these limitations in the current therapies necessitate the search for a better and more efficient cure. Regenerative potency of stem cells in burn wound healing outweigh the traditional treatment procedures. The use of multiple kinds of stem cells are gaining interest due to their enhanced healing efficiency. Distinctions of stem cells include better and faster burn wound healing, decreased inflammation levels, less scar progression and fibrosis on site. In this review, we have discussed the wound-healing process, present methods used for stem cells administration, methods of enhancing stem cells potency and human studies. Pre-clinical and the clinical studies focused on the treatment of thermal and radiation burns using stem cells from 2003 till the present time have been enlisted. Studies shows that the use of stem cells on burn wounds, whether alone or by the help of a scaffold significantly improves healing. Homing of the stem cells at the wound site results in the re-epithelialization, angiogenesis, granulation, inhibition of apoptosis, and regeneration of skin appendages together with reduced infection rate in the human studies. Several studies on animals have shown that stem cells can effectively promote wound healing. Although more research is needed to find out the effectiveness of this treatment in patients with severe burn wounds.

Combining miR-23b exposure with mesenchymal stem cell transplantation enhances therapeutic effects on EAE

Bone marrow mesenchymal stem cells (BMSCs) have the immuno-modulatory capacity to ameliorate autoimmune diseases, such as multiple schlerosis (MS), systemic lupus erythematosus and rheumatoid arthritis. However, BMSC-mediated immunosuppression can be challenging to achieve. The efficacy of BMSC transplantation may be augmented by an adjuvant therapy. Here, we demonstrated that treatment of mice with experimental autoimmune encephalomyelitis (EAE), a model of MS, with BMSCs over-expressing microRNA (miR)-23b provided better synergistic and longer-term therapeutic effects than treatment with traditional BMSCs. Over-expression of miR-23b enhanced the ability of BMSCs to inhibit differentiation of Th17 cells and reduced IL-17 secretion. Compared to traditional BMSCs, the miR-23b over-expressing BMSCs (miR23b-BMSCs) exhibited enhanced secretion of tumor growth factor beta 1 (TGF-β₁), a cytokine that promotes the differentiation of regulatory T (Treg) cells. Pathologically, miR23b-BMSC transplantation delayed EAE progression, apparently by reducing the Th17/Treg cell ratio and inhibiting inflammatory cell infiltration across the blood-brain barrier, and thus slowing spinal cord demyelination. These results may lead to better utility of BMSCs as a treatment for autoimmune diseases.

The effect of allogenic human Wharton's jelly stem cells seeded onto acellular dermal matrix in healing of rat burn wounds

BACKGROUND

Various methods were introduced to overcome the autograft shortage in burn wound care, including cell transplantation and tissue engineering.

AIMS

To evaluate the healing effect of allogenic human Wharton's jelly stem cells (hWJSCs) seeded onto acellular dermal matrix (ADM) in rat burn injuries.

PATIENTS AND METHODS

Human Wharton's jelly stem cells provided from umbilical cord tissue were characterized before transplantation, and the growth kinetic was determined. Skin samples from cosmetic surgeries were used for preparation of ADM. Forty male Sprague Dawley rats were randomly divided into 4 equal groups. Third-degree burn was induced for all animals by exposing to hot water using a 2 cm ring for 10 seconds. Group 1 was burned rats that did not receive any treatment. After burn injury, the second group received silver sulfadiazine (SSD), the third group was treated just by using ADM, and the fourth group received 2 × 10⁶ hWJSCs seeded onto ADM. The animals were euthanized for histologic evaluation after 7, 14, and 21 days.

RESULTS

Human Wharton's jelly stem cells were characterized to be spindle shape and positive for osteogenic and adipogenic induction and for mesenchymal markers but lacked hematopoietic markers. Population doubling time (PDT) was 40.1 hours with an increasing growth trend until day 6th. Macro- and microscopically, the healing was mild in ADM group and moderate in ADM + hWJSCs group after 21 days.

CONCLUSION

Allogenic hWJSCs seeded onto ADM improved the healing process in burn wounds denoting to their therapeutic and anti-inflammatory effects in burn wounds that can be added to the literature.

Prevention of Burn Wound Progression by Mesenchymal Stem Cell Transplantation: Deeper Insights Into Underlying Mechanisms

INTRODUCTION

Burns are dynamic wounds that may present a progressive expansion of necrosis into the initially viable zone of stasis. Therefore, salvage of this zone is a major subject of focus in burn research. The beneficial effects of mesenchymal stem cells (MSCs) on the survival of the zone of stasis have been previously documented. However, many gaps still exist in our knowledge regarding the underlying protective mechanisms. Hence, this study was designed to evaluate the pathophysiological basis of MSCs in the prevention of burn wound progression.

METHODS

Wistar rats received thermal trauma on the back according to the "comb burn" model. Animals were randomly divided into sham, control, and stem cell groups with sacrifice and analysis at 72 hours after the burn. The stasis zones were evaluated using histochemistry, immunohistochemistry, biochemistry, real-time polymerase chain reaction assay, and scintigraphy to evaluate the underlying mechanisms.

RESULTS

Gross evaluation of burn wounds revealed that vital tissue percentage of the zone of stasis was significantly higher in the stem cell group. Semiquantitative grading of the histopathologic findings showed that MSCs alleviated burn-induced histomorphological alterations in the zone of stasis. According to CC3a staining and expression analysis of Bax (B-cell leukemia 2-associated X) and Bcl-2 (B-cell leukemia 2) genes, MSCs attenuated increases in apoptosis postburn. In addition, these transplants showed an immunomodulatory effect that involves reduced neutrophilic infiltration, down-regulation of proinflammatory cytokines (tumor necrosis factor α, interleukin 1β [IL-1β], and IL-6), and up-regulation of the anti-inflammatory cytokine IL-10 in the zone of stasis. Burn-induced oxidative stress was significantly relieved with MSCs, as shown by increased levels of malondialdehyde, whereas the expression and activity of the antioxidant enzyme superoxide dismutase were increased. Finally, MSC-treated interspaces had enhanced vascular density with higher expression levels for vascular endothelial growth factor A, platelet-derived growth factor, fibroblast growth factor, and transforming growth factor β. Gamma camera images documented better tissue perfusion in animals treated with MSCs.

CONCLUSIONS

The protective effects of MSCs are mediated by the inhibition of apoptosis through immunomodulatory, antioxidative, and angiogenic actions.

The application of mesenchymal stem cells to treat thermal and radiation burns

Mesenchymal stem cells (MSCs) have been developed for a number of indications due to their regenerative and anti-inflammatory phenotypes and their utility is enhanced by the fact that allogeneic transplant is feasible with this cell type. Animal studies and early human cases indicate that this has the potential to be an exciting new therapy for treating chronic non-healing wounds such as diabetic ulcers, burns and cutaneous radiation burns. This review will focus on the use of MSCs to treat thermal and radiation burns. Large, severe burns are difficult to treat and pose a major public health burden worldwide. They are characterized by an extensive loss of the outer protective barrier, delayed wound healing, increased oxidative stress and a heightened inflammatory state. The breakdown of the protective barrier results in increased susceptibility to fluid loss and bacterial sepsis. In the case of radiation burns, chronic inflammation can result in subsequent waves of tissue injury leading to skin breakdown and necrosis. The aim of this review is to summarize the current knowledge on MSCs in treating thermal and radiation burns along with the specific scope of characterizing the biologic function of MSCs that help enhance wound healing in these chronic injuries.

Effect of Allogeneic Bone Marrow-mesenchymal Stem Cells (BM-MSCs) to Accelerate Burn Healing of Rat on the Expression of Collagen Type I and Integrin α2β1

BACKGROUND AND OBJECTIVE

Burn is a public health problem, it causes physical disability even death. Treatment of burn wound has been conducted in various ways, but the satisfactory healing has not been provided. Bone marrow-derived mesenchymal stem cells (BM-MSCs) treatment is one of attempt to burn recovery, accelerate wound healing and angiogenesis. This study aimed to investigate the effect of allogeneic BM-MSC treatment on the expression of collagen type I and integrin α2β1 in burn skin tissue of rat observed on day 14.

MATERIALS AND METHODS

Twelve Wistar rats divided into two groups, control group (injected with phospate buffer solution) and treatment group (injected with BM-MSC). Rat was anaesthetized with xylazine and ketamine (ratio 1:1), fur of rat's back was shaved and full thickness burn was made by boiling plate in hot water for 30 min and patched on the back for 20 min. The burns were covered by tegaderm film and elastomult haft. Antalgin as an analgetic was injected to rats during observation process. Burns of rat was observed on day 14. In this study one-way analysis of variance test and Tukey as a further test were analyzed.

RESULTS

The results showed that the healing time of allogeneic BM-MSC treatment on burn skin tissue rats was faster, the thickness of collagen type I in burn skin tissue of rats was thicker (0.977 μm) than controls (0.475 μm) and statistically demonstrated significant differences (p = 0.000). The average percentage of integrin α2β1 expression was higher (2.94%) than control group (2.34%), but the differences were not statistically significant (p = 0.176).

CONCLUSION

The study concluded that BM-MSC treatment was able to accelerate the healing process of burns by increasing the thickness of the collagen and the percentage of integrin α2β1, thus accelerated the cell migration involved during wound healing.

Effect of mesenchymal stem cells and platelet-derived growth factor on the healing of radiation induced ulcer in rats

Radiation-induced skin ulceration is a frequent complication of radiation therapy. This study investigated the effects of rat mesenchymal stem cells (rMSCs) and platelet-derived growth factor (PDGF) on the healing of radiation-induced soft tissue injury. Sprague-Dawley rats (n=17) were irradiated on the right and left buttocks with a single dose of 50 Gy. The right buttocks were administered with phosphatebuffered solution as a control. The left buttocks were administered with either rMSCs (2×10⁶ cells), PDGF (8 µg), or PDGF combined with rMSCs. Administration was done at three weeks after irradiation. Wound healing was analyzed by calculating the percentage of residual ulcerated skin area compared to the total irradiated area during the five week healing period after administration. Modified skin scores were also assessed. Finally, skin lesions were histologically evaluated. More than 40% of the irradiated skin area within the irradiated zone underwent ulceration within 16 days postirradiation, with peak ulceration exceeding 50% around three weeks post-irradiation. Administration of rMSCs or PDGF alone did not confer any significant healing effect. The combined rMSCs+PDGF treatment significantly reduced the wound size compared with the nontreated control up to two weeks postinjection. Regarding the histological examination, lesions administered with PDGF (either alone or mixed with rMSCs) resulted in a greater deposition of highly organized collagen fibers throughout the dermis layer, compared with the control. In conclusion, the combined administration of rMSCs and PDGF efficiently enhanced the healing of radiation-induced skin ulceration.

Expanded endothelial progenitor cells mitigate lung injury in septic mice

Endothelial progenitor cells (EPCs) improve survival and reduce organ failure in cecal ligation and puncture-induced sepsis; however, expanded EPCs may represent an even better approach for vascular repair. To date, no study has compared the effects of non-expanded EPCs (EPC-NEXP) with those of expanded EPCs (EPC-EXP) and mesenchymal stromal cells of human (MSC-HUMAN) and mouse (MSC-MICE) origin in experimental sepsis. One day after cecal ligation and puncture sepsis induction, BALB/c mice were randomized to receive saline, EPC-EXP, EPC-NEXP, MSC-HUMAN or MSC-MICE (1 × 10⁵) intravenously. EPC-EXP, EPC-NEXP, MSC-HUMAN, and MSC-MICE displayed differences in phenotypic characterization. On days 1 and 3, cecal ligation and puncture mice showed decreased survival rate, and increased elastance, diffuse alveolar damage, and levels of interleukin (IL)-1β, IL-6, IL-10, tumor necrosis factor-α, vascular endothelial growth factor, and platelet-derived growth factor in lung tissue. EPC-EXP and MSC-HUMAN had reduced elastance, diffuse alveolar damage, and platelet-derived growth factor compared to no-cell treatment. Tumor necrosis factor-α levels decreased in the EPC-EXP, MSC-HUMAN, and MSC-MICE groups. IL-1β levels decreased in the EPC-EXP group, while IL-10 decreased in the MSC-MICE. IL-6 levels decreased both in the EPC-EXP and MSC-MICE groups. Vascular endothelial growth factor levels were reduced regardless of therapy. In conclusion, EPC-EXP and MSC-HUMAN yielded better lung function and reduced histologic damage in septic mice.

Retention of Endogenous Viable Cells Enhances the Anti-Inflammatory Activity of Cryopreserved Amnion

Objective: Human amniotic membrane (hAM) has been used to treat wounds for more than 100 years. However, widespread use of fresh hAM has been limited due to its short shelf life and safety concerns. To overcome these concerns, different preservation methods have been introduced. The majority of these methods result in devitalized hAM (dev-hAM). Recently, we developed a cryopreservation method that retains all hAM components intact (int-hAM), including viable endogenous cells. To understand the advantages of retaining viable cells in preserved hAM, we compared the anti-inflammatory properties of int-hAM and dev-hAM.

Approach: The tissue composition of int-hAM and dev-hAM was compared with fresh hAM through histology and cell viability analysis. We also evaluated the ability of int-hAM and dev-hAM to regulate tumor necrosis factor-α (TNF-α), interleukin-1α (IL-1α), and IL-10 release when co-cultured with immune cells; to produce prostaglandin E2 (PGE2) on TNF-α stimulation; and to inhibit proteases.

Results: Int-hAM maintained the structural and cellular integrity of fresh hAM. Int-hAM had >80% cell viability post-thaw and remained viable for at least a week in culture. Viable cells were not detected in dev-hAM. Compared with dev-hAM, int-hAM showed significantly greater downregulation of TNF-α and IL-1α, upregulation of PGE2 and IL-10, and stronger inhibition of collagenase.

Innovation and Conclusion: A new cryopreservation method has been developed to retain all native components of hAM. For the first time, we show that viable endogenous cells significantly augment the anti-inflammatory activity of cryopreserved hAM.

The Use of Stem Cells in Burn Wound Healing: A Review

Burn wound healing involves a series of complex processes which are subject to intensive investigations to improve the outcomes, in particular, the healing time and the quality of the scar. Burn injuries, especially severe ones, are proving to have devastating effects on the affected patients. Stem cells have been recently applied in the field to promote superior healing of the wounds. Not only have stem cells been shown to promote better and faster healing of the burn wounds, but also they have decreased the inflammation levels with less scar progression and fibrosis. This review aims to highlight the beneficial therapeutic effect of stem cells in burn wound healing and to discuss the involved pathways and signaling molecules. The review covers various types of burn wound healing like skin and corneal burns, along with the alternative recent therapies being studied in the field of burn wound healing. The current reflection of the attitudes of people regarding the use of stem cells in burn wound healing is also stated.

The immunology of the porcine skin and its value as a model for human skin

The porcine skin has striking similarities to the human skin in terms of general structure, thickness, hair follicle content, pigmentation, collagen and lipid composition. This has been the basis for numerous studies using the pig as a model for wound healing, transdermal delivery, dermal toxicology, radiation and UVB effects. Considering that the skin also represents an immune organ of utmost importance for health, immune cells present in the skin of the pig will be reviewed. The focus of this review is on dendritic cells, which play a central role in the skin immune system as they serve as sentinels in the skin, which offers a large surface area exposed to the environment. Based on a literature review and original data we propose a classification of porcine dendritic cell subsets in the skin corresponding to the subsets described in the human skin. The equivalent of the human CD141(+) DC subset is CD1a(-)CD4(-)CD172a(-)CADM1(high), that of the CD1c(+) subset is CD1a(+)CD4(-)CD172a(+)CADM1(+/low), and porcine plasmacytoid dendritic cells are CD1a(-)CD4(+)CD172a(+)CADM1(-). CD209 and CD14 could represent markers of inflammatory monocyte-derived cells, either dendritic cells or macrophages. Future studies for example using transriptomic analysis of sorted populations are required to confirm the identity of these cells.

Beneficial effects of platelet-derived growth factor on hemorrhagic shock in rats and the underlying mechanisms

Studies have shown that local application of platelet-derived growth factor (PDGF) can be used for the treatment of acute and chronic wounds. We investigated if systemic application of PDGF has a protective effect on acute hemorrhagic shock in rats in the present study. Using hemorrhagic shock rats and isolated superior mesenteric arteries, the effects of PDGF-BB on hemodynamics, animal survival, and vascular reactivity as well as the roles of the gap junction proteins connexin (Cx)40 and Cx43, PKC, and Rho kinase were observed. PDGF-BB (1–15 μg/kg iv) significantly improved the hemodynamics and blood perfusion to vital organs (liver and kidney) as well as vascular reactivity and improved the animal survival in hemorrhagic shock rats. PDGF recovering shock-induced vascular hyporeactivity depended on the integrity of the endothelium and myoendothelial gap junction. Cx43 antisense oligodeoxynucleotide abolished these improving effects of PDGF, whereas Cx40 oligodeoxynucleotide did not. Further study indicated that PDGF increased the activity of Rho kinase and PKC as well as vascular Ca2+ sensitivity, whereas it did not interfere with the intracellular Ca2+ concentration in hypoxia-treated vascular smooth muscle cells. In conclusion, systemic application of PDGF-BB may exert beneficial effects on hemorrhagic shock, which are closely related to the improvement of vascular reactivity and hemodynamics. The improvement of PDGF-BB in vascular reactivity is vascular endothelium and myoendothelial gap junction dependent. Cx43, Rho kinase, and PKC play very important role in this process. These findings suggest that PDGF may be a potential measure to treat acute clinical critical diseases such as severe trauma, shock, and sepsis.

Preparation and antitumor effect of a toxin-linked conjugate targeting vascular endothelial growth factor receptor and urokinase plasminogen activator

The aberrant signaling activation of vascular endothelial growth factor receptor (VEGFR) and urokinase plasminogen activator (uPA) is a common characteristic of many tumors, including lung cancer. Accordingly, VEGFR and uPA have emerged as attractive targets for tumor. KDR (Flk-1/VEGFR-2), a member of the VEGFR family, has been recognized as an important target for antiangiogenesis in tumor. In this study, a recombinant immunotoxin was produced to specifically target KDR-expressing tumor vascular endothelial cells and uPA-expressing tumor cells and mediate antitumor angiogenesis and antitumor effect. Based on its potent inhibitory effect on protein synthesis, Luffin-beta (Lβ) ribosome-inactivating protein was selected as part of a recombinant fusion protein, a single-chain variable fragment against KDR (KDRscFv)-uPA cleavage site (uPAcs)-Lβ-KDEL (named as KPLK). The KDRscFv-uPAcs-Lβ-KDEL (KPLK) contained a single-chain variable fragment (scFv) against KDR, uPAcs, Lβ, and the retention signal for endoplasmic reticulum proteins KDEL (Lys-Asp-Glu-Leu). The KPLK-expressing vector was expressed in Escherichia coli, and the KPLK protein was isolated with nickel affinity chromatography and gel filtration chromatography. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis test demonstrated KPLK was effectively expressed. Result of in vitro cell viability assay on non-small cell lung cancer (NSCLC) H460 cell line (uPA-positive cell) revealed that KPLK significantly inhibited cell proliferation, induced apoptosis, and accumulated cells in S and G2/M phases, but the normal cell line (human submandibular gland cell) was unaffected. These effects were enhanced when uPA was added to digest KPLK to release Lβ. For in vivo assay of KPLK, subcutaneous xenograft tumor model of nude mice were established with H460 cells. Growth of solid tumors was significantly inhibited in animals treated with KPLK up to 21 days, tumor weights were decreased, and the expression of angiogenesis marker CD31 was downregulated; meanwhile, the apoptosis-related protein casspase-3 was upregulated. These results suggested that the recombinant KPLK may have therapeutic applications on tumors, especially uPA-overexpressing ones.

Smac/DIABLO regulates the apoptosis of hypertrophic scar fibroblasts

In abnormal skin wound healing, hypertrophic scars (HS) are characterized by excessive fibroblast hypercellularity and an overproduction of collagen, leading to atypical extracellular matrix (ECM) remodeling. Although the exact mechanisms of HS remain unclear, decreased HS fibroblast (HSFB) apoptosis and increased proliferation are evident in the development of HS. In this study, the contribution of the second mitochondria-derived activator of caspases/direct inhibitor of apoptosis protein (IAP)-binding protein with a low isoelectric point (pI) (Smac/DIABLO), an apoptosis-promoting protein released from the mitochondria, was investigated in human normal skin and HSFB cultures. The expression of Smac/DIABLO is usually decreased in many malignant tumors compared with normal tissues. Immunohistochemical analysis of skin tissues and the western blot analyses of fibroblasts revealed that the expression of Smac/DIABLO was lower in HS tissues compared with normal skin tissues. Of note, adenovirus-mediated Smac/DIABLO overexpression in the cultured HSFBs significantly reduced cell proliferation, as detected by the cell counting kit-8, and increased caspase-3 and -9 activity, as detected by spectrofluorimetry. In addition, it increased apoptosis, as detected by fluorescence-activated cell sorting (FACS). Furthermore, we found that the silencing of Smac with siRNA in the HSFBs induced a noticeable decrease in caspase-3 and -9 activity, leading to a significant reduction in apoptosis. In addition, the mRNA expression of type I and III pro-collagen detected in the HSFBs was significantly increased following the silencing of Smac with siRNA and was inhibited following Smac/DIABLO overexpression, as shown by real-time RT-PCR. In conclusion, Smac/DIABLO decreases the proliferation and increases the apoptosis of HSFBs. To our knowledge, the data from our study suggest for the first time that Smac/DIABLO is a novel therapeutic target for HS.

Transplantation of BMSCs expressing hVEGF165 /hBD3 promotes wound healing in rats with combined radiation-wound injury

The combined radiation-wound injury is a refractory wound with decreased number or dysfunction of repairing cells and growth factors. This remains a challenge in clinical practice. The object of this study is to evaluate the therapeutic efficacy of a combination of human vascular endothelial growth factor 165 (hVEGF(165)) and human beta-defensin 3 (hBD3) in the treatment of such wounds. A plasmid-carrying hVEGF(165) gene and hBD3 gene was used to transfect rat bone-marrow-derived mesenchymal stem cells (BMSCs). The supernatant from the modified BMSCs significantly promoted the proliferation and cell migration of human endothelial cells and it also inhibited the growth of bacteria and fungus, demonstrating the successful expression of the transfected genes. The hVEGF(165)/hBD3-modified BMSCs were then injected into the sites of combined radiation-wound injury on rats. It demonstrated that wound-healing time was shortened significantly in the treated rats. The granulation tissue formation/maturation, skin appendage regeneration and collagen deposition were also improved significantly. Strong expression of hVEGF(165) and hBD3 was detected in the wound surface at early stage of the healing. The results indicate that topical transplantation of hVEGF(165)/hBD3-modified BMSCs promoted wound healing, and this gene therapy strategy presents a promising approach in the treatment of refractory wounds such as the combined radiation-wound injury.

Modulation of inflammation by Cicaderma ointment accelerates skin wound healing

Skin wound healing is a natural and intricate process that takes place after injury, involving different sequential phases such as hemostasis, inflammatory phase, proliferative phase, and remodeling that are associated with complex biochemical events. The interruption or failure of wound healing leads to chronic nonhealing wounds or fibrosis-associated diseases constituting a major health problem where, unfortunately, medicines are not very effective. The objective of this study was to evaluate the capacity of Cicaderma ointment (Boiron, Lyon, France) to accelerate ulcer closure without fibrosis and investigate wound healing dynamic processes. We used a necrotic ulcer model in mice induced by intradermal doxorubicin injection, and after 11 days, when the ulcer area was maximal, we applied Vaseline petroleum jelly or Cicaderma every 2 days. Topical application of Cicaderma allowed a rapid recovery of mature epidermal structure, a more compact and organized dermis and collagen bundles compared with the Vaseline group. Furthermore, the expression of numerous cytokines/molecules in the ulcer was increased 11 days after doxorubicin injection compared with healthy skin. Cicaderma rapidly reduced the level of proinflammatory cytokines, mainly tumor necrosis factor (TNF)-α and others of the TNF pathway, which can be correlated to a decrease of polymorphonuclear recruitment. It is noteworthy that the modulation of inflammation through TNF-α, macrophage inflammatory protein-1α, interleukin (IL)-12, IL-4, and macrophage-colony-stimulating factor was maintained 9 days after the first ointment application, facilitating the wound closure without affecting angiogenesis. These cytokines seem to be potential targets for therapeutic approaches in chronic wounds. Our results confirm the use of Cicaderma for accelerating skin wound healing and open new avenues for sequential treatments to improve healing.

Acute radiation syndrome caused by accidental radiation exposure - therapeutic principles

Fortunately radiation accidents are infrequent occurrences, but since they have the potential of large scale events like the nuclear accidents of Chernobyl and Fukushima, preparatory planning of the medical management of radiation accident victims is very important. Radiation accidents can result in different types of radiation exposure for which the diagnostic and therapeutic measures, as well as the outcomes, differ. The clinical course of acute radiation syndrome depends on the absorbed radiation dose and its distribution. Multi-organ-involvement and multi-organ-failure need be taken into account. The most vulnerable organ system to radiation exposure is the hematopoietic system. In addition to hematopoietic syndrome, radiation induced damage to the skin plays an important role in diagnostics and the treatment of radiation accident victims. The most important therapeutic principles with special reference to hematopoietic syndrome and cutaneous radiation syndrome are reviewed.