Attachment and proliferation of human gingival fibroblasts seeded on barrier membranes using Wharton's jelly-derived stem cells conditioned medium: An in vitro study.

The effect of Wharton's jelly mesenchymal stem cells conditioned medium (WJMSCs-CM) and zinc oxide nanoparticles (ZnO-NPs) on cultured human gingival fibroblasts on various barrier membranes was investigated in this study. In this study, human gingival fibroblasts were prepared and cultured on three membranes: collagen membrane, acellular dermal matrix (ADM) with ZnO-NPs, and ADM without ZnO-NPs. WJMSCs-CM was given to the testing groups, while control groups received the same membranes without WJMSCs-CM. Following 48 and 72 h, 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) tests were performed to assess cell survival. Cell proliferation on the membranes was also evaluated using 4',6-diamidino-2-phenylindole (DAPI) staining after 48 and 72 h. Field emission scanning electron microscopy was used to determine membrane surface structure and cell adhesion. Nanoparticles were also subjected to an energy-dispersive x-ray analysis to identify their chemical structure. Two-way analysis of variance was used to conduct the statistical analysis. The p-value ≤.05 was considered significant. When ADM-ZnO-NPs were combined with CM, fibroblast viability, and adhesion significantly differed from ADM-ZnO-NPs alone. DAPI results confirmed cell proliferation in all six groups on both experiment days. The abundance and concentrated distribution of cells during cell proliferation were found in CM-containing membranes, specifically the ADM-ZnO-NPs membrane, demonstrating the improved biocompatibility of the ADM-ZnO-NPs membrane for cell proliferation. The other groups did not significantly differ from one another. WJMSCs-CM positively affected the viability and proliferation of gingival fibroblasts, but only marginally. Under certain conditions, ZnO-NPs below a specific concentration increased the biocompatibility of the membranes.

Fabrication and evaluation of the regenerative effect of a polycaprolactone/chitosan nanofibrous scaffold containing bentonite nanoparticles in a rat model of deep second-degree burn injury.

Objectives: In the present study, we evaluated the effect of a nanofibrous scaffold including polycaprolactone (PCL), chitosan (CHT), and bentonite nanoparticles (Ben-NPS) on wound healing in order to introduce a novel dressing for burn wounds. Materials and Methods: PCL, PCL/CHT, and PCL/CHT/Ben-NPS nanofibrous scaffolds were fabricated by the electrospinning technique. Their structural and physiochemical characteristics were investigated by Fourier-transform infrared spectroscopy (FTIR) analysis, scanning electron microscopy (SEM), tensile strength, water contact angle, as well as, swelling and degradation profiles test. The disc diffusion assay was carried out to investigate the antibacterial potential of the scaffolds. In addition, the cell viability and proliferation ability of human dermal fibroblasts (HDFs) on the scaffolds were assessed using MTT assay as well as SEM imaging. The wound-healing property of the nanofibrous scaffolds was evaluated by histopathological investigations during 3,7, and 14 days in a rat model of burn wounds. Results: SEM showed that all scaffolds had three-dimensional, beadles-integrated structures. Adding Ben-NPS into the PCL/CHT polymeric composite significantly enhanced the mechanical, swelling, and antibacterial properties. HDFs had the most cell viability and proliferation values on the PCL/CHT/Ben-NPS scaffold. Histopathological evaluation in the rat model revealed that dressing animal wounds with the PCL/CHT/Ben-NPS scaffold promotes wound healing. Conclusion: The PCL/CHT/Ben-NPS scaffold has promising regenerative properties for accelerating skin wound healing.

Study the Effect of Calendula officinalis Extract Loaded on Zinc Oxide Nanoparticle Cream in Burn Wound Healing.

The skin, the body's largest organ, acts as a protective barrier against pathogens and environmental damage. Skin burns can result from heat, chemicals, friction, or electricity. Nanoscience has recently been utilized to create ointments and creams for burns. Zinc oxide nanoparticles are crucial due to their antimicrobial and antioxidant properties. In this study, a cream containing nanoparticles was loaded with calendula extract, and its ability to promote tissue healing was investigated in Wistar rats with skin burns. The zinc oxide nanoparticles were chemically synthesized and loaded with calendula extract. The morphology and physicochemical properties of the nanoparticles were confirmed by SEM, ZETA size, XRD, and FTIR assays. The MTT technique was employed to assess the cream's impact on fibroblast growth. The antimicrobial activity of the nanoparticles was investigated against Pseudomonas using the MIC method. Real-time PCR was used to determine the expression of the Bax and Bcl-2 genes in aeruginosa. The results showed that zinc oxide nanoparticles at high concentrations increased the proliferation of the fibroblast cells. Histopathological studies showed granulation and epithelialization of the tissue without any hemorrhage or tissue infection during the first days of treatment with this cream. The animal models treated with the cream showed an increase in Bcl-2 gene expression and a decrease in Bax expression. We concluded that zinc oxide nanoparticles loaded with calendula extract have a practical effect in healing burn wounds due to their unique antibacterial properties of zinc oxide nanoparticles and their anti-inflammatory and wound-healing effects. The synergistic effect of these two substances significantly improved the healing process. This newly developed cream can be introduced as a successful and viable treatment option in burn wounds.

Local Flap Reconstruction of Burn Contractures in Extremities and Neck: A Nine-Year Experience with Long-Term Outcome Evaluation in Southwestern Iran.

Background: Treating burn scar contractures remains challenging for reconstructive surgeons; no clear guidelines declare the optimal and most effective technique. We evaluated the efficacy of local flaps in treating patients with post-burn contractures. Methods: This retrospective study included 243 patients with post-burn contractures referred to Taleghani Hospital (Khuzestan, southwest Iran) for local flap reconstruction from 2011 to 2020. Patients' demographic data, detailed descriptions of scars, surgical procedures, and flap outcomes were assessed. A plastic surgeon conducted all surgical procedures, the goals of which were to release the scar and cover the defect. Joint range of motion (ROM) (according to goniometric measurements), complications, need for second-stage surgery, and patient satisfaction were assessed. Results: After scar release, 70.4% of joints were covered with a Z-plasty and similar local flaps, 26.1% with a Z-plasty plus skin grafts, and 3.5% with only skin grafts. The outcome after one year revealed a significant improvement in mean ROM (by 45.80% of the normal ROM; P< 0.001). The mean functional and aesthetic satisfaction scores were 9.45 and 7.61 out of 10, respectively. The complication rate was 10.82%: re-contracture occurred in 3.82%, flap tip necrosis in 1.27%, and partial flap necrosis in 0.31%. Conclusion: Simple local flaps such as the Z-plasty are safe and effective in covering the joint following post-burn contracture release. Due to the feasibility, minimal need for facilities, steep learning curve, acceptable functional and aesthetic outcomes, and low complication rate, we strongly recommend the Z-plasty for reconstructing burn contractures, particularly in LMICs.

The internal aqueous phase gelation improves the viability of probiotic cells in a double water/oil/water emulsion system.

This research studied the viability of probiotic bacterium Lactobacillus plantarum (L. plantarum) encapsulated in the internal aqueous phase (W 1) of a water-in-oil-in-water (W 1/O/W 2) emulsion system, with the help of gelation and different gelling agents. Additionally, the physicochemical, rheological, and microstructural properties of the fabricated emulsion systems were assessed over time under the effect of W 1 gelation. The average droplet size and zeta potential of the control system and the systems fabricated using gelatin, alginate, tragacanth gum, and carrageenan were 14.7, 12.0, 5.1, 6.4, and 7.3 µm and - 21.1, -34.1, -46.2, -38.3, and -34.7 mV, respectively. The results showed a significant increase in the physical stability of the system and encapsulation efficiency of L. plantarum after the W 1 gelation. The internal phase gelation significantly increased the viability of bacteria against heat and acidic pH, with tragacanth gum being the best gelling agent for increasing the viability of L. plantarum (28.05% and 16.74%, respectively). Apparent viscosity and rheological properties of emulsions were significantly increased after the W 1 gelation, particularly in those jellified with alginate. Overall, L. plantarum encapsulation in W 1/O/W 2 emulsion, followed by the W 1 gelation using tragacanth gum as the gelling agent, could increase both stability and viability of this probiotic bacteria.

Preparation and evaluation of a polycaprolactone/chitosan/propolis fibrous nanocomposite scaffold as a tissue engineering skin substitute.

Introduction: Recently, the application of nanofibrous mats for dressing skin wounds has received great attention. In this study, we aimed to fabricate and characterize an electrospun nanofibrous mat containing polycaprolactone (PCL), chitosan (CTS), and propolis for use as a tissue-engineered skin substitute. Methods: Raw propolis was extracted, and its phenolic and flavonoid contents were measured. The physiochemical and biological properties of the fabricated mats, including PCL, PCL/CTS, and PCL/CTS/Propolis were evaluated by scanning electron microscopy (SEM), atomic force microscopy (AFM), mechanical analysis, swelling and degradation behaviors, contact angle measurement, cell attachment, DAPI staining, and MTT assay. On the other hand, the drug release pattern of propolis from the PCL/CTS/Propolis scaffold was determined. A deep second-degree burn wound model was induced in rats to investigate wound healing using macroscopical and histopathological evaluations. Results: The results revealed that the propolis extract contained high amounts of phenolic and flavonoid compounds. The fabricated scaffold had suitable physicochemical and mechanical properties. Uniform, bead-free, and well-branched fibers were observed in SEM images of mats. AFM analysis indicated that the addition of CTS and propolis to PCL elevated the surface roughness. MTT results revealed that the electrospun PCL/CTS/Propolis mat was biocompatible. The presence of fibroblast cells on the PCL/CTS/Propolis mats was confirmed by DAPI staining and SEM images. Also, propolis was sustainably released from the PCL/CTS/Propolis mat. The animal study revealed that addition of propolis significantly improved wound healing. Conclusion: The nanofibrous PCL/CTS/Propolis mat can be applied as a tissue-engineered skin substitute for healing cutaneous wounds, such as burn wounds.

MRI tracking of human Wharton's jelly stem cells seeded onto acellular dermal matrix labeled with superparamagnetic iron oxide nanoparticles in burn wounds.

Background: In vivo cell tracking after transplantation in regenerative medicine remains an unmet challenge and limits current understanding of the wound healing mechanism through cell-based therapies. This study investigated tracking of human Wharton's jelly stem cells (hWJSCs) seeded onto an acellular dermal matrix (ADM) and labeled with superparamagnetic iron oxide nanoparticles (SPIONs) by magnetic resonance imaging (MRI) in burn injury. Method: The hWJSCs were characterized and assessed for growth kinetics. A total of 30 rats were enrolled in three equal groups. Group 1 underwent scald burn injury left without treatment, the group 2 was treated by an ADM that was prepared from cosmetic surgery skin samples and the group 3 received hWJSCs labeled with SPIONs seeded onto an ADM. Tensile strength was evaluated before and after interventions, real time PCR assessed apoptosis, and Prussian blue staining, scanning electron microscopy (SEM) and MRI were used for the tracking of labeled cells. Results: The hWJSCs exhibited mesenchymal stem cell properties. Population doubling time was 40.1 hours. SPIONs did not show any toxic effect. The hWJSCs seeded onto an ADM decreased Bax and increased Bcl-2 gene expression. Internalization of SPIONs within hWJSCs was confirmed by Prussian blue staining, SEM and MRI until day 21. There was a significant difference between the Young's moduli of normal skin and the group receiving hWJSCs seeded onto an ADM. Histological observations and SEM imaging confirmed that MRI is an accurate method to track SPION-labeled hWJSCs in vivo. Conclusions: This study showed that SPION labeling coupled with MRI can be used to further understand the fate of stem cells after transplantation in a burn model.

Acute lung injury induced by acute uremia and renal ischemic-reperfusion injury: The role of toll-like receptors 2 and 4, and oxidative stress.

Objectives: Acute lung injury (ALI) is a common complication of distant organ dysfunction induced by acute kidney injury (AKI). Toll-like receptors (TLRs) have a critical role in progression of AKI. The main goal of this study was to determine whether lung gene expression of TLR2 and TLR4 change by ischemic (renal bilateral ischemic-reperfusion; BIR) and uremic (bilateral nephrectomy; BNX) AKI. Materials and Methods: Forty male rats were divided into five groups. Two kidneys were removed in BNX, and renal pedicles were clamped in BIR for 45 min. The kidney and lung tissue, and blood samples were collected and saved after 24 hr in all groups. The bone marrow mesenchymal stem cells were immediately injected (1×106,IV) into the treated groups. The expression of TLR2, TLR4, TNF-α, and VEGF was checked by RT-PCR in the tissue samples. MDA level, SOD, and CAT activity were evaluated in the tissue samples. Results: Structural disturbance of ALI was detected as alveolar hemorrhage and vascular congestion after BIR and BNX. Lung TLR2 and TLR4 but not TNF-α and VEGF up-regulated in these groups. Oxidative stress stabilized after the BIR and BNX in the tissue samples. BMSCs reduce the expression of TLR2 and TLR4 and oxidative stress in the treated groups. Conclusion: Acutely gathering systemic mediators after renal ischemic or uremic injury induce ALI through overexpression of TLR2 and TLR4 and oxidative stress. Therefore, the Lung protective effect of BMSCs may be related to modulation of TLR2 and TLR4 and oxidative stress in the kidney and lung tissue.

Preparation and evaluation of polycaprolactone/chitosan/Jaft biocompatible nanofibers as a burn wound dressing.

Tissue engineering is an emerging method for replacing damaged tissues. In this study, the potential application of electrospun polycaprolactone/chitosan/ the internal layer of oak fruit (Jaft) as skin scaffolds was investigated. A combination of Polycaprolactone (PCL), chitosan (CH), and the internal layer of oak fruit (Jaft) was used to incorporate mechanical properties of synthetic polymers, biological properties of natural polymers, and antibacterial activity of Jaft. Physical and morphological characteristics of prepared scaffolds were investigated using a scanning electron microscope (SEM), mechanical analysis, swelling ratio, and contact angle. Moreover, chemical and biological properties were evaluated by Fourier-transform infrared spectroscopy (FTIR), chromatography, flow cytometry, DAPI staining, MTT assay, and trypan blue exclusion assay. Obtained results demonstrated that the fabricated scaffolds have good mechanical properties. Moreover, the addition of chitosan and Jaft to the PCL scaffolds improved their water absorption capacity as well as surface hydrophilicity. MTT results showed the fabricated nanofibrous scaffolds have adequate cell viability, which is higher than the cell culture plate at each time point of culture. Furthermore, SEM images of cultured scaffolds, trypan blue exclusion assay, and DAPI staining confirmed that fibroblast cells could be well-attached and proliferate on the PCL/CH/Jaft scaffolds. Results have proven that this novel bioactive scaffold has promising mechanical properties, suitable biocompatibility in vitro, and in vivo. Consequently, it could be a promising candidate for skin tissue engineering applications.

Therapeutic effects of bone marrow mesenchymal stem cells via modulation of TLR2 and TLR4 on renal ischemia-reperfusion injury in male Sprague-Dawley rats.

Introduction: Acute kidney injury (AKI) induced by renal ischemia-reperfusion (I/R) injury is a pro-inflammatory process that activates toll-like receptors (TLRs). Stem cell therapy holds a great promise for kidney repair. Therefore, we investigated the immunomodulatory role of bone marrow stromal cells (BMSCs) on TLR2 and TLR4 expression in AKI in male Sprague-Dawley rats. Methods: BMSCs were isolated from the bone marrow of male rats, cultured in DMEM, and characterized using appropriate markers before transplantation. Renal I/R was induced by 45 minutes bilateral ischemia followed by 24 hours of reperfusion. Rats received intraperitoneal injections of BMSCs (1.5 × 106 cells, i.p, per rat) immediately after termination of renal ischemia. Serum samples were collected pre-and post-stem cells injection for assessment of blood urea nitrogen (BUN) and creatinine (Cr) levels. The kidneys were harvested after 24 hours of reperfusion for structural and molecular analysis. Results: Renal I/R caused severe tissue injuries and increased the level of BUN (166.5 ± 12.9 vs. 18.25 ± 1.75) and Cr (3.7 ± 0.22 vs. 0.87 ± 0.06) compared to the sham group. In addition, mRNA expression of TLR2 and TLR4 elevated in the renal I/R group. Administration of BMSCs improved the functional and structural state of the kidney induced by I/R and down-regulated TLR2 and TLR4 gene expression. Conclusion: The results showed a highly significant renoprotection by BMSCs that indicates their therapeutic potential in I/R injures. These effects are most likely associated with the TLR2/4 signaling pathway via modulation of the inflammatory response cascades.

The Epidemiology of Burn and Lethal Area of Fifty Percentage (LA50) in Children in Shiraz, Southern Iran.

BACKGROUND: This study was conducted to assess the epidemiology of burn and lethal area of fifty percentage (LA50) in children in Shiraz, Southern Iran. METHODS: In this case series study, 619 hospitalized burn children from burn centers affiliated to Shiraz University of Medical Sciences, Shiraz, Iran from 2012 to 2016 were enrolled. Demographic characteristics of patients such as age, gender, place and cause of burn, and morality rate were evaluated. LA50 was measured using Probit analysis. RESULTS: The mean age of patients was 4.4±3.4 years. The mortality rate in burn patients was 8.7% and LA50 of total body surface area (TBSA%) ranged from 40.1% in 2012 to 68.3% in 2016. Although the number of male burn patients (65%) was more than females (35%), the mortality rate in females was more than males (11.4% vs. 7.2%). Scald and flame were the most common causes of burn. CONCLUSION: The findings in our burn center comparing burn patients to developed countries showed that LA50 and survival rate were lower denoting to an urgent necessity to promote current policies in burn care and prevention and to decrease the mortality rate too.

Effect of dermal fibroblasts and mesenchymal stem cells seeded on an amniotic membrane scaffold in skin regeneration: A case series.

BACKGROUND: Skin wound healing has always been a challenging subject as it involves the coordinated functioning of various cells and molecules. Any disorder in wound healing can cause healing failure and result in chronic wounds. In this study, we hypothesized that co-cultured dermal fibroblasts (DFs) and Wharton's jelly mesenchymal stem cells (WJ-MSCs) seeded on an acellular amniotic membrane scaffold could be used to promote skin regeneration in chronic ulcers. MATERIALS AND METHODS: In this case series, the chronic wounds of five diabetic patients aged between 30 and 60 years were treated with co-cultured WJ-MSCs and DFs seeded on an acellular amniotic membrane. Treatment was applied and the wound healing process was evaluated every three days for nine days, with the patients being subsequently followed up for one month. The wound healing percentage, time taken for the wound to heal, and wound size were monitored. RESULTS: The mean wound healing rate (WHR) increased progressively in all lesions. The mean percentage of wound healing after transplantation of the biological scaffold enriched with WJ-MSCs and autologous DFs after treatment was 93.92%, respectively. The healing percentage significantly increased after three days; significant decreases in wound size and healing time were recorded after six and nine days of treatment, respectively (p < 0.002); and total skin regeneration and re-epithelialization were achieved by the ninth day of treatment. There were no side effects or complications. CONCLUSION: Given the current problems and complications presented by chronic wounds, Novel Clinical approaches involving cell therapy and tissue engineering can be regarded as an attractive therapeutic option for the treatment of chronic and difficult-to-heal wounds.

Syringic Acid: A Potential Natural Compound for the Management of Renal Oxidative Stress and Mitochondrial Biogenesis in Diabetic Rats.

BACKGROUND: Diabetic nephropathy can lead to renal diseases; oxidative stress and mitochondrial dysfunction have critical roles in its development. OBJECTIVES: In this study, the effect of syringic acid (SYR), a natural phenolic acid, on diabetic nephropathy and mitochondrial biogenesis was examined. METHODS: Diabetes was induced in rats by injecting streptozotocin. SYR (25, 50 and 100 mg/kg/day) was orally administered for 6 weeks. SYR effects on factors, such as antioxidant activities and mRNA expression level of mitochondrial biogenesis indexes, were evaluated. RESULTS: In SYR-treated rats, blood glucose and ALP level were significantly reduced. SYR increased kidney GSH content in the diabetic group. Elevated renal catalase and superoxide dismutase activities in diabetic rats were restored to normal levels after treatment. SYR significantly reduced the renal TBARS level, which had increased in diabetic rats. This compound also significantly upregulated renal mRNA expression of PGC-1α and NRF-1, and increased mtDNA/nDNA ratio in diabetic rats. These values were reduced in the non-treated diabetic group. The results show improvement of histopathological damages of kidney in the SYR treated group in comparison with the diabetic group. CONCLUSION: According to the results, SYR alters renal antioxidant defense mechanisms. Also, it could be considered as a novel approach by targeting mitochondria in renal diabetic complications.

Butyl methyl imidazolium silica sulfate (BMIm)SS: A novel hybrid nano-catalyst for highly efficient synthesis of new 1,2-diol monoesters of ibuprofen as the novel prodrugs of ibuprofen having potent analgesic property.

The fabrication, characterization of butyl methyl imidazolium silica sulfate [BMIm]SS as a novel nano hybrid catalyst and its application in synthesis of new ibuprofen (IBP) 1,2-diol mono esters were described. [BMIm]SS catalyzed the reaction of IBP with epoxides to afford the new IBP 1,2-diol mono esters in good to excellent yields. The products were tested in vivo for the analgesic properties on female mice using formalin test. The test results revealed that most compounds, in particular compounds 1h, 1k and 1o displayed potent analgesic activity compare to IBP as a reference drug. No mortality was observed due to the toxicity of the synthesized compounds. The docking analysis was conducted that confirmed the strong binding affinity of active compounds to active site of murine cyclooxygenase-2 (COX-2) enzyme compare to IBP. The in silico pharmacokinetic profile, drug likeness and toxicity predictions were carried out for all compounds which determined that 1h can be suggested as an appropriate future drug candidate.

The Healing Effect of Aloe Vera Gel on Acetic Acid-Induced Ulcerative Colitis in Rat.

BACKGROUND The use of herbal and synthetic compounds can be effective in improving the areas and repair of tissues that have been affected during the processes like what happens in ulcerative colitis (UC) as a common inflammatory disorder. According to the beneficial effects of aloe vera, in this study, we aimed to assess the therapeutic effects of oral aloe vera gel on acetic acid-induced colitis in rats by histopathological and molecular analysis of Bax, and BCL-2 genes expression (using RT-PCR technique) in colon tissue samples. METHODS This experimental study comprised 32 adult male Sprague Dawley rats weighting 220 ± 20 g that were randomly divided into four groups as follows. The control group (healthy rats), colitis group in which UC was induced by transrectal administration of 3% acetic acid with no treatment, oral form of sulfasalazine group in which UC was induced by transrectal administration of 3% acetic acid, then was treated by oral administration of sulfasalazine 500 mg/kg body weight, and the fourth group which received oral form of aloe vera gel (200 mg / kg) for 21 days, respectively after induction of UC. Then, the therapeutic effects of treatment groups were compared with the control group and the colitis group with no treatment, by the assessment of histopathological and molecular changes in the colon tissues of rats on the 7th, 14th, and 21st days. Finally, the collected data were analyzed using statistical tests. RESULTS Histologically, aloe vera gel treatment could reduce and heal colon tissue damages in induced colitis. Also, this gel reduced apoptosis in rat's colon with acetic acid-induced colitis, which showed in significantly decreased in Bax mRNA expression and significantly increased BCL-2 mRNA expression compared with the colitis group with no treatment. CONCLUSION Aloe vera gel has a significant effect on the treatment of UC in rat because of the beneficial effect that was found from aloe vera such as decreasing the severity of colitis as evidenced by histopathological findings, and with respect to apoptosis and gene expression that were related to wound healing process, and suppression of the elevation of Bax mRNA with the upregulation of Bcl-2, which can be considered effective in the treatment of UC.

Polyurethane/chitosan/hyaluronic acid scaffolds: providing an optimum environment for fibroblast growth.

OBJECTIVE: Biodegradable polymers can replace damaged tissue components using tissue engineering techniques. The objective of this study is to determine an optimum environment for polymer scaffolds to improve the proliferation of fibroblast cells capable of wound repair. METHOD: In this study, the addition of polysaccharides, such as chitosan (CH) or hyaluronic acid (HA), to a polyurethane (PU) polymer was evaluated using different methods to determine if they affect scaffold morphology and cell activity of fibroblasts prepared from human foreskin tissues. Mechanical properties, such as tensile strength, contact angle and swelling test, were used to check the physical and mechanical properties of the scaffold. Fibroblast growth was also measured at 24, 48 and 72 hours. RESULTS: Scanning electron microscopy (SEM) determined that a 3:1 ratio of PU/CH scaffold, developed by electrospinning, allowed the formation of a uniform structure in scaffold fibres. Physical mechanical tests showed that PU electrospun scaffolds were not modified by the addition of CH. The mean stretch and mean water absorption increased significantly using the PU/CH scaffold, compared with the PU scaffold. However, the mean tensile strength and the mean contact angle, used to study space and porosity, did not differ between scaffolds. Fourier transform infrared spectroscopy confirmed the functional groups (-OH, -NH and -C=O) in the PU/CH scaffold, compared with PU or CH chemical structures alone. HA was then added to CH and PU/CH scaffolds to evaluate the growth of fibroblast cells. Results showed that cell viability and the number of cells, using MTT and trypan blue exclusion assay, respectively, increased significantly at 24, 48 and 72 hours of culture in PU/CH/HA scaffold compared to HA, CH/HA, and PU/HA. Moreover, PU/HA at 48 and 72 hours also increased cell viability and cell numbers compared to HA and CH/HA scaffolds. However, scaffolds at 72 hours had limited space for cell growth. Moreover, SEM data demonstrated that fibroblasts were able to proliferate, penetrate, migrate and survive on PU/HA and PU/CH/HA three-dimensional scaffolds, especially during the first 48 hours. Furthermore, 4',6-diamidino-2-phenylindole (DAPI) staining confirmed that fibroblasts could penetrate PU scaffolds and showed higher cell viability and lower cellular damage in PU/CH/HA, compared to CH/HA and PU/HA scaffolds. Finally, flow cytometry using CD90 and CD105 surface markers revealed that >90% of cells isolated from the human dermis were fibroblasts. CONCLUSION: In summary, PU/HA and PU/CH/HA scaffolds were found to be biocompatible and provided a suitable environment for the growth and proliferation of fibroblasts, which filled and covered all pores between the fibres. The new scaffold used in this study, made of synthetic and natural polymers, is a good candidate for applications in tissue engineering. It is therefore recommended to use PU in grafts or in wound dressing.

The role of labeled cell therapy with and without scaffold in early excision burn wounds in a rat animal model.

OBJECTIVES: One of the essential problems in burn therapy is performing the permanent replacement of skin in full and deep thickness injuries. Human Wharton's Jelly mesenchymal stem cells (HWJMSCs) have a unique combination of prenatal and postnatal properties. Decellularized human amniotic membrane (DHAM) can be used as a scaffold for HWJMSCs-therapy. We aimed to evaluate the quantity and quality of healing in the early excision burn wound dressing with 3-dimensional and 2- dimensional cell cultures. MATERIALS AND METHODS: Amniotic and umbilical cords were isolated from the mothers who were candidates for cesarean section. HAM was decellularized using the mechanical and enzymatic method. HWJMSCs were isolated and cultured; cell surface markers were examined for authentication of MSCs and labeled using a viral vector containing the cGFP gene. Burns were created using brass bar in 32 adult male Albino rats and randomly divided into four groups (DHAM+HWJMSCs, injection of HWJMSCs, HWJMSCs was spread on the wound, and DHAM alone). Rats were sacrificed on the 7th and 14th days for pathological examination of the wound. Comparisons between the study groups were made by one-way analysis of variance. RESULTS: Wound healing process in DHAM+HWJMSCs was much more progressed during the first week in comparison to other groups, and exhibited significant differences in re-epithelialization, formation of granulation tissue, and hemorrhage (P<0.05). CONCLUSION: The utility of the amniotic scaffold seeded by the human mesenchymal stem cells is recommended for accelerating the healing process.

Vascularization strategies for skin tissue engineering.

A number of challenges in skin grafting for wound healing have drawn researchers to focus on skin tissue engineering as an alternative solution. The core idea of tissue engineering is to use scaffolds, cells, and/or bioactive molecules to help the skin to properly recover from injuries. Over the past decades, the field has significantly evolved, developing various strategies to accelerate and improve skin regeneration. However, there are still several concerns that should be addressed. Among these limitations, vascularization is known as a critical challenge that needs thorough consideration. Delayed wound healing of large defects results in an insufficient vascular network and ultimately ischemia. Recent advances in the field of tissue engineering paved the way to improve vascularization of skin substitutes. Broadly, these solutions can be classified into two categories as (1) use of growth factors, reactive oxygen species-inducing nanoparticles, and stem cells to promote angiogenesis, and (2) in vitro or in vivo prevascularization of skin grafts. This review summarizes the state-of-the-art approaches, their limitations, and highlights the latest advances in therapeutic vascularization strategies for skin tissue engineering.

Nanoencapsulation of Andrographolide Rich Extract for the Inhibition of Cervical and Neuroblastoma Cancer Cells.

Andrographis paniculata is traditionally used for many diseases and scientifically proven for anti-cancer property. Andrographolide which is the marker compound is believed to be the main contributor to the pharmacological activities. The poor solubility and bioavailability of this diterpenoid lactone could be overcome by nanoencapsulation. Reflux extraction, and followed by successive Soxhlet fractionation were used to obtain andrographolide rich extract from the herb. Spontaneous emulsion solvent diffusion was used to nanoencapsulate andrographolide using poly(lactic-co-glycolic acid) with 1% polyvinyl alcohol as emulsifier. Nanospheres loaded with andrographolide was found to have the particle size, 163 nm; polydispersity index, 0.26 and zeta potential, - 57.85 mV. The encapsulation efficiency and in vitro drug release were 80.0% and 84.2%, respectively. The andrographolide nanoparticles could inhibit the proliferation of cervical and neuroblastoma cells with no adverse effect on normal human skin cells. Andrographolide rich extract loaded nanoparticles could inhibit the proliferation of HeLa and SH-SY5Y cells, mainly through Bax-induced apoptosis. The result was consistent with the low expression of anti-apoptotic genes (Bcl-2 and Bcl-xL) and prognostic factor (Ki-67). The tumour size of HeLa bearing mice was significantly reduced (73%) after treated with andrographolide rich nanoparticles (10 mg/kg body weight) for a month.

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.