Resveratrol-coated chitosan mats promote angiogenesis for enhanced wound healing in animal model.

BACKGROUND: Growing incidences of chronic wounds recommend the development of optimal therapeutic wound dressings. Electrospun nanofibers have been considered to show potential wound healing properties when accompanied by other wound dressing materials. This study aimed to explore the potential role of Chitosan (CS) nanofibrous mats coated with resveratrol (RS) as an antioxidant and pro-angiogenic agent in rat models of skin wound healing. METHODS: Electrospun chitosan/polyethylene oxide (PEO) nanofibers were prepared using electrospinning technology and coated by 0.05 and 0.1 mg.ml resveratrol named as (CS/RS 0.05) and (CS/RS 0.1), respectively. The scaffolds were characterized physiochemically such as in vitro release study, TGA, FTIR spectroscopy analysis, biodegradability, and human dermal fibroblast seeding assay. The scaffold was subsequently used in vivo as a skin substitute on a rat skin wound model. RESULTS: In vitro tests revealed that all scaffolds promoted cell adhesion and proliferation. However, more cell viability was observed in CS/RS 0.1 scaffold. The biocompatibility of the scaffolds was validated by MTT assay, and the results did not show any toxic effects on human dermal fibroblasts. It was observed that RS-coated scaffolds had the ability to release RS in a controlled manner. In in vivo tests CS/RS 0.1 scaffold had the greatest impact on the healing process by improving the neodermis formation and modulated inflammation in wound granulation tissue. Histological analysis revealed enhanced vascular endothelial growth factor expression, epithelialization and increased depth of wound granulation tissue. CONCLUSIONS: The RS-coated CS/PEO nanofibrous scaffold accelerates wound healing and may be useful as a dressing for cell transfer and clinical skin regeneration.

Antibacterial and antioxidant double-layered nanofibrous mat promotes wound healing in diabetic rats.

Diabetic wounds are problematic to heal owing to microbial infections as well as decreased proliferation and high concentrations of reactive oxygen species. In this study, a double-layered nanofibrous mat containing grape seed extract (GSE) and silver sulfadiazine (SSD) was fabricated. A synthetic biodegradable polymer, e.g., polycaprolactone (PCL), and a natural material (i.e., collagen) were employed as wound dressing substances. The results showed that GSE possesses antioxidant activity which can be helpful in reducing free radicals. The platform exhibited antibacterial activity against gram-positive and -negative bacteria. The double-layered nanofibrous mat containing GSE and SSD not only was not toxic but also amplified the cell proliferation compared to a pure mat, showing the effect of plant extract. After induction of a round wound, the animals were divided into three groups, namely (1) normal group (receiving + GSE/-GSE nanofiber), (2) diabetic group (receiving + GSE/-GSE nanofiber), and (3) control group (receiving gauze). In vivo evaluation demonstrated no significant differences in the healing process of normal rats. Surprisingly, fully repaired skin was observed on day 14 in the double-layered nanofibrous mat containing GSE in the normal and diabetic groups whereas the wound of diabetic rats treated with pure mat was not completely healed. The macroscopic and microscopic results after 14 days showed the following order in wound repair: Normal/ + GES > Diabetic/ + GSE > Normal/-GES > Diabetic/-GSE > control (with gauze) (p < 0.05). Accordingly, the double-layered nanofibrous mat containing GSE and SSD used in the present study could be considered as a suitable wound dressing in order to shorten healing time and prevent infection during the wound healing process.

Spleen extracellular matrix provides a supportive microenvironment for ß-cell function.

Objectives: Type 1 diabetes mellitus is a common autoimmune and multifactorial disorder. Researchers have been interested in making a favorable islet-like tissue model for the treatment of diabetes. The main objective of this study was to determine the effects of the spleen extracellular matrix (S-ECM) on the function of the MIN6 cell line (a ß-cell model). Materials and Methods: In this experimental research, Wistar rat spleens were decellularized by sodium dodecyl sulfate (SDS) and Triton X-100. S-ECM was characterized by histological assessments, scanning electron microscopy, determination of residua DNA, and examination of the mechanical tensile property. Then, MIN6 cells were seeded on S-ECM scaffold. Glucose-stimulated insulin secretion and mRNA expression of insulin-related genes were examined to confirm the function of the cells. Results: The main components of S-ECM such as collagen and glycosaminoglycan remained after decellularization. Furthermore, very low residual DNA and appropriate mechanical behavior of S-ECM provided an ideal extracellular microenvironment for the MIN6 cells. GSIS results showed that the seeded cells in S-ECM secreted more insulin than the traditional two-dimensional (2D) culture. The expression of specific insulin-related genes such as PDX-1, insulin, Maf-A, and Glut-2 in the recellularized scaffold was more significant than in the 2D traditional cultured cells. Also, MTT assay results showed that S-ECM were no cytotoxic effects on the MIN6 cells. Conclusion: These results collectively have evidenced that S-ECM is a suitable scaffold for stabilizing artificial pancreatic islands.

Redesigning of 3-Dimensional Vascular-Muscle Structure Using ADSCs/HUVECs Co-Culture and VEGF on Engineered Skeletal Muscle ECM.

OBJECTIVE: The main objective of this study is to determine the myogenic effects of skeletal muscle extracellular matrix, vascular endothelial growth factor and human umbilical vein endothelial cells on adipose-derived stem cells to achieve a 3-dimensional engineered vascular-muscle structure. MATERIALS AND METHODS: The present experimental research was designed based on two main groups, i.e. monoculture of adipose tissue-derived stem cells (ADSCs) and co-culture of ADSCs and human umbilical vein endothelial cells (HUVECs) in a ratio of 1:1. Skeletal muscle tissue was isolated, decellularized and its surface was electrospun using polycaprolactone/gelatin parallel nanofibers and then matrix topography was evaluated through H and E, trichrome staining and SEM. The expression of MyHC2 gene and tropomyosin protein were examined through real-time reverse transcription polymerase chain reaction (RT-PCR) and immunofluorescence, respectively. Finally, the morphology of mesenchymal and endothelial cells and their relationship with each other and with the engineered scaffold were examined by scanning electron microscopy (SEM). RESULTS: According to H and E and Masson's Trichrome staining, muscle tissue was completely decellularized. SEM showed parallel Polycaprolactone (PCL)/gelatin nanofibers with an average diameter of about 300 nm. The immunofluorescence proved that tropomyosin was positive in the ADSCs monoculture and the ADSCs/HUVECs coculture in horse serum (HS) and HS/VEGF groups. There was a significant difference in the expression of the MyHC2 gene between the ADSCs and ADSCs/HUVECs culture groups (P<0.05) and between the 2D and 3D models in HS/ VEGF differentiation groups (P<001). Moreover, a significant increase existed between the HS/VEGF group and other groups in terms of endothelial cells growth and proliferation as well as their relationship with differentiated myoblasts (P<0.05). CONCLUSION: Co-culture of ADSCs/HUVECs on the engineered cell-free muscle scaffold and the dual effects of VEGF can lead to formation of a favorable engineered vascular-muscular tissue. These engineered structures can be used as an acceptable tool for tissue implantation in muscle injuries and regeneration, especially in challenging injuries such as volumetric muscle loss, which also require vascular repair.

Mesenchymal stem cells derived from the kidney can ameliorate diabetic nephropathy through the TGF-ß/Smad signaling pathway.

Diabetic nephropathy (DN) has been introduced as one of the main microvascular complications in diabetic patients, the most common cause of end-stage renal disease (ESRD). Based on the therapeutic potential of mesenchymal stem cells in tissue repair, we aimed to test the hypothesis that kidney stem cells (KSCs) might be effective in the kidney regeneration process. Stem cells from rat kidney were separated, and the surface stem cell markers were determined by flow cytometry analysis. Thirty-two Sprague Dawley rats were divided into four groups (control, control that received kidney stem cells, diabetic, diabetic treated with stem cells). To establish diabetic, model STZ (streptozotocin) (60 mg/kg) was used. The KSCs were injected into experimental groups via tail vein (2 × 106 cells/rat). In order to determine the impact of stem cells on the function and structure of the kidney, biochemical and histological parameters were measured. Further, the expression of miRNA-29a, miR-192, IL-1ß, and TGF-ß was determined through the real-time PCR technique. Phosphorylation of Smad2/3 was evaluated by using the standard western blotting. The KSCs significantly reduced blood nitrogen (BUN), serum creatinine (Scr), and 24-h urinary proteins in DN (P < 0.05). IL-1ß and TGF-ß significantly increased in the kidney of diabetic rats. In addition, the expression of miR-29a is significantly increased, whereas miR-192 decreased after treatment with KSCs (P < 0.05). Diabetic rats showed an increased level of phosphorylation of both Smad2 and Smad3 (P < 0.05). Periodic acid-Schiff (PAS) staining showed improved histopathological changes in the presence of KSCs. Stem cells derived from adult rat kidney may be an option for treating the early DN to improve the functions and structure of kidneys in rats with DN.

Effects of Exosomes Derived from Kidney Tubular Cells on Diabetic Nephropathy in Rats.

OBJECTIVE: One of the severe complications and well-known sources of end stage renal disease (ESRD) from diabetes mellitus is diabetic nephropathy (DN). Exosomes secreted from diverse cells are one of the novel encouraging therapies for chronic renal injuries. In this study, we assess whether extracted exosomes from kidney tubular cells (KTCs) could prevent early stage DN in vivo. MATERIALS AND METHODS: In this experimental, exosomes from conditioned medium of rabbit KTCs (RK13) were purified by ultracentrifuge procedures. The exosomes were assessed in terms of morphology and size, and particular biomarkers were evaluated by transmission electron microscopy (TEM), scanning electron microscopy (SEM), Western blot, atomic force microscopy (AFM) and Zetasizer Nano analysis. The rats were divided into four groups: DN, control, DN treated with exosomes and sham. First, diabetes was induced in the rats by intraperitoneial (i.p.) administration of streptozotocin (STZ, 50 mg/kg body weight). Then, the exosomes were injected each week into their tail vein for six weeks. We measured 24-hour urine protein, blood urea nitrogen (BUN), and serum creatinine (Scr) levels with detection kits. The histopathological effects of the exosomes on kidneys were evaluated by periodic acid-Schiff (PAS) staining and expressions of miRNA-29a and miRNA-377 by quantitative real-time polymerase chain reaction (qRT-PCR). RESULTS: The KTC-Exos were approximately 50-150 nm and had a spherical morphology. They expressed the CD9 and CD63 specific markers. Intravenous injections of KTC-Exos potentially reduced urine volume (P<0.0001), and 24- hour protein (P<0.01), BUN (P<0.001) and Scr (P<0.0001) levels. There was a decrease in miRNA-377 (P<0.01) and increase in miRNA-29a (P<0.001) in the diabetic rats. KTC-Exos ameliorated the renal histopathology with regulatory changes in microRNAs (miRNA) expressions. CONCLUSION: KTC-Exos plays a role in attenuation of kidney injury from diabetes by regulating the miRNAs associated with DN.

Therapeutic Effect of Kidney Tubular Cells-Derived Conditioned Medium on the Expression of MicroRNA-377, MicroRNA-29a, Aquapurin-1, Biochemical, and Histopathological Parameters Following Diabetic Nephropathy Injury in Rats.

Background: Diabetic nephropathy (DN) is a critical complication of diabetes mellitus. This study evaluates whether administration of conditioned medium from kidney tubular cells (KTCs-CM) has the ability to be efficacious as an alternative to cell-based therapy for DN. Materials and Methods: CM of rabbit kidney tubular cells (RK13; KTCs) has been collected and after centrifugation, filtered with 0.2 filters. Four groups of rats have been utilized, including control, DN, DN treated with CM, and sham group. After diabetes induction by streptozotocin (50 mg/kg body weight) in rats, 0.8 ml of the CM was injected to each rat three times per day for 3 consecutive days. Then, 24-h urine protein, blood urea nitrogen (BUN), and serum creatinine (Scr) have been measured through detection kits. The histopathological effects of CM on kidneys were evaluated by periodic acid-Schiff staining and the expression of microRNAs (miRNAs) 29a and 377 by using the real-time polymerase chain reaction. The expression of aquapurin-1 (AQP1) protein was also examined by Western blotting. Results: Intravenous injections of KTCs-CM significantly reduced the urine volume, protein 24-h, BUN, and Scr, decreased the miRNA-377, and increased miRNA-29a and AQP1 in DN treated with CM rats. Conclusion: KTCs-CM may have the potential to prevent kidney injury from diabetes by regulating the microRNAs related to DN and improving the expression of AQP1.

Aligned Poly(ε-caprolactone) Nanofibers Superimposed on Decellularized Human Amniotic Membrane Promoted Myogenic Differentiation of Adipose Derived Stem Cells.

OBJECTIVE: This study was designed to fabricate a suitable permanent scaffold for the normal aligned myotube formation and improve the process of myogenic differentiation of selected stem cells. MATERIALS AND METHODS: In this experimental study, an engineered scaffold composed of decellularized human amniotic membrane (DHAM) and electrospun fibers of poly(ε-caprolactone) (PCL) was fabricated and characterized. PCL nanofibers were superimposed on DHAM (PCL-DHAM) in two different patterns, including randomized fibers (Random) and aligned fibers (Aligned). Adipose derived stem cells (ADSCs) were isolated from adult Wistar rats and cultured on designed scaffold and induced to myotube differentiation. Using an MTT assay, the vitality of cells was determined. Then, myogenic cell differentiation was assessed using scan electron microscopy (SEM), immunofluorescence assay, and reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: The mechanical properties of engineered PCL-DHAM composite improved significantly compared to DHAM as a control. The engineered PCL-DHAM promoted cell growth and high expression of myosin, Mhc2 and myogenin and thus enhanced the myotube formation. CONCLUSION: These findings revealed that bio-composite membrane prepared from PCL nanofibers and DHAM, may represent a promising biomaterial as a desirable scaffold for applying in the bioengineered muscle repair.

Fabrication and Characterization of Glycerol/Chitosan/Polyvinyl Alcohol-Based Transparent Hydrogel Films Loaded with Silver Nanoparticles for Antibacterial Wound Dressing Applications.

BACKGROUND: Wounds have a bad prognostic nature and excessive discharges whose regular wound dressings are ineffective. Hydrogels are the best candidates for dressing such wounds due to their high water content and ability to exchange substances. Accordingly, the purpose of this study was to make a novel hydrogel wound dressing following the integration of various findings on wound healing and the use of regenerative medicine. MATERIALS AND METHODS: Various compounds were fabricated by glycerol/chitosan/polyvinyl alcohol (PVA) and then characterized to obtain the optimal composition using several techniques, including a water vapor passage test, scanning electron microscopy, water absorption, tensile strength, biodegradability, Fourier transform infrared spectroscopy, and antibacterial test. RESULTS: The findings revealed the optimal dressing ratio. Better antibacterial activity was found for the silver nanoparticle (AgNP) dressing. CONCLUSION: Our new fabricated dressing, glycerol/chitosan/PVA hydrogel loaded with AgNPs, exhibited satisfactory wound healing properties.

Role of Vascular Endothelial Growth Factor and Human Umbilical Vein Endothelial Cells in Designing An In Vitro Vascular-Muscle Cellular Model Using Adipose-Derived Stem Cells.

OBJECTIVE: Researchers have been interested in the creation of a favorable cellular model for use in vascular-muscle tissue engineering. The main objective of this study is to determine the myogenic effects of vascular endothelial growth factor (VEGF) and human umbilical vein endothelial cells (HUVECs) on adipose-derived stem cells (ADSCs) to achieve an in vitro vascular-muscle cellular model. MATERIALS AND METHODS: The present experimental research was conducted on two primary groups, namely ADSCs monoculture and ADSCs/HUVECs co-culture that were divided into control, horse serum (HS), and HS/VEGF differentiation subgroups. HUVECs were co-cultured by ADSC in a ratio of 1:1. The myogenic differentiation was evaluated using the reverse transcription-polymerase chain reaction (RT-PCR) and immunofluorescence in different experimental groups. The interaction between ADSCs and HUVECs, as well as the role of ADSCs conditional medium, was investigated for endothelial tube formation assay. RESULTS: Immunofluorescence staining indicated that Tropomyosin was positive in ADSCs and ADSCs and HUVECs co-culture groups on HS and HS/VEGF culture medium. Furthermore, the MyHC2 gene expression significantly increased in HS and HS/VEGF groups in comparison with the control group (P<0.001). More importantly, there was a significant difference in the mRNA expression of this gene between ADSCs and ADSCs and HUVECs co-culture groups on HS/VEGF culture medium (P<0.05). Current data revealed that the co-culture of ADSCs and HUVECs could develop endothelial network formation in the VEGF-loaded group. Also, the ADSCs-conditioned medium improved the viability and formation of the endothelial tube in the HS and VEGF groups, respectively. CONCLUSION: It was concluded that ADSCs/HUVECs co-culture and dual effects of VEGF can lead to the formation of differentiated myoblasts in proximity to endothelial network formations. These in vitro cellular models could be potentially used in vascular-muscle tissue engineering implanted into organ defects where muscle tissue and vascular regeneration were required.

The effect of glycyrrhizin acid on Bax and Bcl2 expression in hepatotoxicity induced by Titanium dioxide nanoparticles in rats.

AIM: This research studied the effects of glycyrrhizic acid (GA) on apoptosis induced with by titanium dioxide (NTiO2) in the liver of rats. BACKGROUND: It is widely accepted that the contamination resulting from nanoparticles (NPs) is an emerging dangerous issue. Metal oxide nanoparticles have high environmental stability and cause toxicity in the food chain. Thus, the present study investigated the anti-apoptotic effects of glycyrrhizic acid (GA) on the hepatotoxicity generated by titanium dioxide (NTiO2) NPs in the liver tissue. METHODS: Thirty-two male Wistar rats were randomly divided into four groups. NTiO2-treated rats were given 300 mg / kg of NTiO2 solution via gavage for 14 days; GA-treated were administered 100 mg/kg GA for 14 days; protection group was pre-treated with GA before NTiO2 administration for 7 days. Then, apoptotic index was evaluated through immunolocalization of Bax and Bcl-2 and TUNEL assay. RESULTS: we found that HSCORE of Bax expression and apoptotic index experienced a significant increase with NTiO2 (P <0.001), while Bcl-2 expression significantly diminished in NTiO2-treated rats (P <0.001). The results revealed that the increased Bax expression and apoptotic index were reversed by GA and enhanced the activities of Bcl2. CONCLUSION: The results revealed that GA effectively attenuated apoptosis against NTiO2 in rats.

Incorporation of Silver Sulfadiazine into An Electrospun Composite of Polycaprolactone as An Antibacterial Scaffold for Wound Healing in Rats.

OBJECTIVE: Fabrication of an antibiotic-loaded scaffold with controlled release properties for wound dressing is one of tissue engineering challenges. The aim of this study was to evaluate the wound-healing effectiveness of 500-µm thick polycaprolactone (PCL) nanofibrous mat containing silver sulfadiazine (SSD) as an antibacterial agent. MATERIALS AND METHODS: In this experimental study, an electrospun membrane of PCL nanofibrous mat containing 0.3% weight SSD with 500 µm thickness, was prepared. Morphological and thermomechanical characteristics of nanofibers were evaluated. Drug content and drug release properties as well as the surface hydrophobicity of the nanofibrous membrane were determined. Antimicrobial properties and cellular viability of the scaffold were also examined. A full thickness wound of 400 mm2 was created in rats, to evaluate the wound-healing effects of PCL/SSD blend in comparison with PCL and vaseline gas used as the control group. RESULTS: SSD at a concentration of 0.3% improved physicochemical properties of PCL. This concentration of SSD did not inhibit the attachment of human dermal fibroblasts (HDFs) to nanofibers in vitro, but showed antibacterial activity against Gram-positive Staphylococcus aureus (ST) and Gram-negative Pseudomonas aeruginosa (PS). Overall, results showed that SSD improves characteristics of PCL nanofibrous film and improves wound-healing process in one-week earlier compared to control. CONCLUSION: Cytotoxicity of SSD in fabricated nanofibrous mat is a critical challenge in designing an effective wound dressing that neutralizes cellular toxicity and improves antimicrobial activity. The PCL/SSD nanofibrous membrane with 500- µm thickness and 0.3% (w/v) SSD showed applicable characteristics as a wound dressing and it accelerated wound healing process in vivo.

Isolating human dermal fibroblasts using serial explant culture.

BACKGROUND: The purpose of this study was to introduce an applicable culture technique to isolate human dermal fibroblasts (HDFs); which could also contribute to research, clinical practices, as well as tissue engineering. METHODS: Samples from the human skin were dissected and cultured via serial explant technique. Subsequently, the isolated fibroblasts were assessed for their protein markers and genetic variations via immunofluorescence (IF) and karyotyping; respectively. Following the employment of this technique, a small piece of explant completely disappeared; while no dermis remained after 10 days. RESULTS: The quantity of HDFs harvested through this culture technique was reported at a normal level. The results of immunostaining also indicated that the isolated fibroblasts had expressed vimentin and fibronectin; whereas no cells had shown cytokeratin and epidermal marker. Moreover, karyotyping results for the fibroblasts isolated by the given technique revealed no chromosomal diversity after passage 20. CONCLUSIONS: It was concluded that serial explant culture was an efficient technique for isolating HDFs from a small piece of skin in short-time periods; which could also preserve their normal morphology and molecular characteristics.

Effects of Quercetin-Loaded Nanoparticles on MCF-7 Human Breast Cancer Cells.

: Background and objectives: Previous studies have shown anti-tumor activity of quercetin (QT). However, the low bioavailability of QT has restricted its use. This study aimed to assess the toxic effect of QT encapsulated in solid lipid nanoparticles (QT-SLNs) on the growth of MCF-7 human breast cancer cells. Materials and Methods: MCF-7 and MCF-10A (non-tumorigenic cell line) cell lines treated with 25 µmol/mL of QT or QT-SLNs for 48 h. Cell viability, colony formation, oxidative stress, and apoptosis were evaluated to determine the toxic effects of the QT-SLNs. Results: The QT-SLNs with appropriate characteristics (particle size of 85.5 nm, a zeta potential of -22.5 and encapsulation efficiency of 97.6%) were prepared. The QT-SLNs showed sustained QT release until 48 h. Cytotoxicity assessments indicated that QT-SLNs inhibited MCF-7 cells growth with a low IC50 (50% inhibitory concentration) value, compared to the free QT. QT-SLNs induced a significant decrease in the viability and proliferation of MCF-7 cells, compared to the free QT. QT-SLN significantly increased reactive oxygen species (ROS) level and MDA contents and significantly decreased antioxidant enzyme activity in the MCF-7 cells. Following QT-SLNs treatment, the expression of the Bcl-2 protein significantly decreased, whereas Bx expression showed a significant increase in comparison with free QT-treated cells. Furthermore, The QT-SLNs significantly increased apoptotic and necrotic indexes in MCF-7 cells. Viability, proliferation, oxidative stress and apoptosis of MCF-10A cells were not affected by QT or QT-SLNs. Conclusion: According to the results of this study, SLN significantly enhanced the toxic effect of QT against human breast cancer cells.

MafA Overexpression: A New Efficient Protocol for In Vitro Differentiation of Adipose-Derived Mesenchymal Stem Cells into Functional Insulin-Producing Cells.

OBJECTIVE: We proposed a novel differentiation method for the efficient differentiation of adipose-derived mesenchymal stem cells (ADMSCs) into functional insulin-producing cells (IPCs) based on MafA overexpression. MATERIALS AND METHODS: In this experimental study, a eukaryotic expression vector containing MafA [MafA/pcDNA3.1(+)] was constructed and purified. ADMSCs were differentiated into IPCs. ADMSCs were assigned in two groups including control (C), and the MafA overexpressed (MafA+) groups. The ADMSCs were transfected by MafA/pcDNA 3.1(+) at day 10 of the differentiation. Differentiated cells were analyzed for the expression of multiple ß cell specific genes (Nkx2.2, Ngn3, Isl-1, Pdx1, MafA, Nkx6.1, and Insulin) using real-time polymerase chain reaction (PCR). The insulin secretion potency of the differentiated cells in response to glucose exposure was also determined using an enzyme-linked immunosorbent assay (ELISA) method and Dithizone (DTZ) staining. The IPCs from the control manipulated group, and un-differentiated ADMSCs group were transplanted to streptozotocin (STZ)-diabetic rats. Rats were monitored for blood glucose and insulin concentration. RESULTS: The results revealed that ADMSCs were successfully differentiated into IPCs through the 14 day differentiation protocol. The expression of ß-cell specific genes in MafA+ IPCs was higher than in control cells. Glucose-induced insulin secretion after the exposure of IPCs to glucose was higher in MafA+ group than the control group. The STZdiabetic rats showed an ability to secrete insulin and apparent hyperglycemic condition adjustment after transplantation of the control IPCs. The mean insulin concentration of diabetic rats that were transplanted by manipulated IPCs was significantly higher than ADMSCs-transplanted rats; however, no effect was observed in the concentration of bloodn glucose. CONCLUSION: The overexpression of MafA can be used as a novel promising approach for the efficient production of IPCs from ADMSCs in vitro. However, the future therapeutic use of the MafA+ IPCs in diabetic animals needs further investigations.

Application of polycaprolactone, chitosan, and collagen composite as a nanofibrous mat loaded with silver sulfadiazine and growth factors for wound dressing.

Fabrication of nanofibrous biomaterials composed of natural and synthetic materials that incorporated with antibiotic and growth factors with controlled release manner is an attractive topic in wound healing. The purpose of this study was to prepare optimal composite of materials as biomimetic nanofibrous mats for application in wound healing. The mat was prepared of polycaprolactone (PCL) in the bottom, chitosan/poly ethylene oxide (Cs/PEO) in the middle, and PCL/collagen (PCL/Coll) in the top layer. A panel of standard characterization tests of nanofibrous mat was performed and its compatibilities in strength and integration were confirmed. Middle layer was loaded with epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF), and silver sulfadiazine (SSD) was incorporated in the bottom layer as an anti-infection factor. Then, on the dorsum of rats, a 400-mm2 wound was created and surrounded by a silicone ring to control the usual tissue contractions. Nanofibrous mats with or without growth factors were applied as wound dressings and at day 14, the healing process was evaluated. At day 14, the treated group by designed mat showed faster epithelialization and angiogenesis. Silicone ring in the test group was desirable in wound closure compared to the control group. Reformation of skin tissue was manifested in a shorter time. This composite nanofibrous mat could be introduced as a dynamic and effective candidate for wound dressing.

The combined effect of Pdx1 overexpression and Shh manipulation on the function of insulin-producing cells derived from adipose-tissue stem cells.

Pancreatic and duodenal homeobox 1 (Pdx1) and Sonic hedgehog (Shh) are the key regulators of beta-cell function. In vitro experiments have shown that there is significant cooperation between Pdx1 and Shh with regard to the production and maintenance of insulin-producing cells (IPCs). In this study, the combined effect of Pdx1 overexpression and Shh manipulation on the function of adipose tissue-derived IPCs was determined. A eukaryotic expression vector (Pdx1- pCDNA3.1(+)) was constructed and transfected into a Chinese hamster ovary (CHO) cell line. Adipose tissue-derived mesenchymal stem cells (ADMSCs) obtained from rats were assigned to two groups [control (C) and manipulated (M)] and differentiated into IPCs. Manipulated cells were treated with a mixture of FGF-ß and cyclopamine and recombinant Shh protein at days 3 and 11, respectively, and transfected with Pdx1- pCDNA3.1(+) at day 10. The expression of multiple genes related to function of beta cells was analyzed using real-time PCR. The functionality of IPCs in vitro was analyzed through dithizone (DTZ) staining and ELISA. IPCs were injected into the tail vein of diabetic rats, and blood glucose and insulin concentrations were measured. CHO cells transfected with Pdx1- pCDNA3.1(+) showed a significantly higher expression of Pdx1 compared with nontransfected cells. Manipulated IPCs exhibited a significantly higher expression of MafA, Nkx2.2, Nkx6.1, Ngn3, insulin, and Isl1 and a higher insulin secretion in response to glucose challenge in relation to control cells. Rats that received manipulated IPCs exhibited a higher ability to normalize blood glucose and insulin secretion when compared to controls. Our protocol might be used for more efficient cell therapy of patients with diabetes in the future.

Anticancer Activity of Curcumin-Loaded PLGA Nanoparticles on PC3 Prostate Cancer Cells.

Curcumin (Cur) has been found to be very efficacious against many different types of cancer cells. However, the major disadvantage associated with the use of Cur is its low systemic bioavailability. Our present work investigated the toxic effect of encapsulation of Cur in PLGA (poly lactic-coglycolic acid) nanospheres (NCur) on PC3 human cancer prostate cell. In the present study, we have investigated the effects of NCur on growth, autophagia, and apoptosis in PC3 cells, respectively, by MTT assay, fluorescence microscopy, and Flow cytometry. MTT assays revealed that the NCur at the concentration of 25 µg/mL for 48 h were able to exert a more pronounced effect on the PC3 cells as compared to free Cur. Apoptotic index was significantly increased in NCur-treated cells compared to free Cur. The percentage of autophagic cells (LC3-II positive cells) was also significantly increased in NCur treatment in comparison to free Cur. These data indicate that the NCur has considerable cytotoxic activity more than Cur on PC3 cell lines, which is mediated by induction of both apoptotic and autophagic processes. Thus, NCur has high potential as an adjuvant therapy for clinical application in prostate cancer.

Curcumin-loaded poly lactic-co-glycolic acid nanoparticles effects on mono-iodoacetate -induced osteoarthritis in rats.

Curcumin has been found to be very efficacious against many different types of diseases. However, the major disadvantage associated with the use of curcumin is its low systemic bioavailability. In the present study the protective effects of curcumin-loaded poly lactic-co-glycolic acid nanoparticles (nanocurcumin) against mono-iodoacetate-induced osteoarthritis in rats was investigated. Mono-iodoacetate was injected into right knee joints to induce osteoarthritis. In experimental groups, 14 days after injection of mono-iodoacetate, curcumin (200 mg kg-1) and nanocurcumin (200 mg kg-1) were gavaged, respectively, for two weeks. Then the rats were sacrificed and the right knee joints were removed and fixated in 10% formalin for histological assessments. Cellularity and matrix staining were significantly increased in articular cartilage of curcumin-treated animals compared to mono-iodoacetate group (p < 0.01). These effects were significantly (p < 0.01) more in nanocurcumin-treated animals. These results suggested that administration of nanocurcumin prevented the structural changes of articular cartilage in mono-iodoacetate model of osteoarthritis in rats.

Sonic hedgehog pathway suppression and reactivation accelerates differentiation of rat adipose-derived mesenchymal stromal cells toward insulin-producing cells.

BACKGROUND AIMS: Sonic hedgehog (Shh) is an intercellular signaling molecule that regulates pancreas development in mammals. Manipulation of Shh signaling pathway can be used as reliable approach to improve the generation of functional insulin-producing cells (IPCs) from mesenchymal stromal cells (MSCs). METHODS: In the present study, a novel differentiation protocol was used to produce IPCs from adipose tissue-derived MSCs (ATDMSCs) based on sequential inhibition and reactivation of Shh pathway. ATDMSCs were differentiated into IPCs via a 14-day basic protocol using 1% insulin transferrin selenium (ITS) and 1% nicotinamide in Dulbecco's Modified Eagle's Medium medium. A mixture of 0.25 µmol/L cyclopamine + 64 ng/mL basic fibroblast growth factor at day 3 of differentiation and 150 ng/mL recombinant Shh at day 11 of differentiation were used, respectively, to promote sequential inhibition and reactivation of Shh pathway. Insulin granule formation, glucose-stimulated insulin secretion and gene expression pattern related to the pancreatic endocrine development and function were analyzed in manipulated and unmanipulated IPCs. RESULTS: IPCs obtained after Shh manipulation secreted higher amounts of insulin in vitro. This phenotype was accompanied by increased expression of both genes critical for ß-cell function and transcription factors associated with their mature phenotype including Pdx1, MafA, Nkx2.2, Nkx6.1, Ngn3, Isl1 and insulin at day 14 of differentiation. CONCLUSIONS: Our findings indicated that the early inhibition and late reactivation of Shh signaling pathway during the differentiation of ATDMSCs improved the functional properties of IPCs, a novel method that could be considered as an alternative approach for cell-based therapy for type 1 diabetes.