Fibroblast Cell Growth Research Articles

New anti-proliferative triterpenes from hydrolyzate of total Gynostemma pentaphyllum saponins induces cell cycle arrest and apoptosis in human breast cancer cells

• Three undescribed triterpenes were obtained from hydrolyzate of G. pentaphyllum . • All the isolated compounds exhibited significant cytotoxic activity. • Gypensapogenin II possessed good anti-proliferative selectivity against Bcap37 cells. • It significantly inhibited proliferation and migration led to G1 cells cycle arrest. • It also induced apoptosis in Bcap37 cells through mitochondrial pathway. Phytochemical investigation of the hydrolysate in total Gynostemma pentaphyllum saponins led to the isolation of three previously undescribed triterpenes, Gypensapogenin II ( 1 ), Gypensapogenin III ( 2 ), and Gypensapogenin IV ( 3 ), together with five known compounds. Their structures were mainly identified by NMR and HR-ESI-MS data. All isolated compounds were evaluated in Bcap37, A549, Hela, and HepG-2 cells and showed significant anti-cancer activities, while having a much weaker effect on the growth of normal human breast cells (MCF-10a) and lung fibroblast cells (MRC5). Among the compounds, compound 1 possessed good anti-proliferative selectivity against Bcap37 cells (IC 50 value of 6.13 ± 0.86 μM). Furthermore, basic mechanism studies revealed that compound 1 significantly decreased survival and inhibited proliferation and migration leading to G1 cell cycle arrest and apoptosis in Bcap37 cells through mitochondrial pathway. Taken together, these results indicated compound 1 exerted promising anti-proliferative activity, and inhibited the migration and promoted the apoptosis of Bcap37 cells.

Stimuli-responsive electrospun nanofibers based on PNVCL-PVAc copolymer in biomedical applications.

Poly(N-vinylcaprolactam) (PNVCL) is a suitable alternative for biomedical applications due to its biocompatibility, biodegradability, non-toxicity, and showing phase transition at the human body temperature range. The purpose of this study was to synthesize a high molecular weight PNVCL-PVAc thermo-responsive copolymer with broad mass distribution suitable for electrospun nanofiber fabrication. The chemical structure of the synthesized materials was detected by FTIR and 1HNMR spectroscopies. N-Vinyl caprolactam/vinyl acetate copolymers (159,680 molecular weight (g/mol) and 2.51 PDI) were synthesized by radical polymerization. The phase transition temperature of N-vinyl caprolactam/vinyl acetate copolymer was determined by conducting a contact angle test at various temperatures (25, 26, 28, and 30 [Formula: see text]). The biocompatibility of the nanofibers was also evaluated, and both qualitative and quantitative results showed that the growth and proliferation of 929L mouse fibroblast cells increased to 80% within 48h. These results revealed that the synthesized nanofibers were biocompatible and not cytotoxic. The results confirmed that the synthesized copolymers have good characteristics for biomedical applications.

Comparative study of cell growth and cellular adhesion on Ti-6Al-4V surfaces made by Selective Laser Melting followed by different surface post processing steps

Selective laser melting is generally considered as to improve the design of medical implants, thus supporting medical treatment and maintaining mobility of invalid and older people. In particular, medical grade titanium alloys are in favour for spinal implants, as being nowadays manufactured by, e.g., milling. Selective laser melting offers the advantage of an adapted elasticity as to avoid stress shielding within the backbone by including complex lattice structures inside the individualized implant. For the integration into the backbone, surface properties, particularly surface roughness, are crucial with respect to biocompatibility and cell growth. Opposite to conventional milling, selective laser melting, however, results in an inferior surface roughness, leading to the necessity of downstream process steps.We report on cell growth and cellular adhesion of human primary fibroblasts on medical grade Ti-6Al-4V fabricated by selective laser melting followed by combinations of milling, hot isostatic pressing, chemical surface treatment and steam-sterilization to generate different surface conditions for cell growth. For example, cell growth is studied for varying milling path spacing on SLM parts exhibiting different surface roughness. Our results reveal good cell growth for milling path spacing lower than 0.18 mm as compared to higher milling path spacing and not milled surfaces. Cell fluorescence images and SEM images show that the cell growth is additionally hampered by the edges of the milling path. Conveniently, process failures such as pores originating from the selective laser melting process do not hamper the cell growth.

LINC01915 Facilitates the Conversion of Normal Fibroblasts into Cancer-Associated Fibroblasts Induced by Colorectal Cancer-Derived Extracellular Vesicles through the miR-92a-3p/KLF4/CH25H Axis.

Increasing long non-coding RNAs are reported to regulate the cell growth, apoptosis, and metastasis of cancer-associated fibroblasts (CAFs).This study aimed to explore how LINC01915 influences the conversion of normal fibroblasts (NFs) into CAFs in colorectal cancer (CRC). LINC01915 expression was initially measured in clinical tissue samples and in NFs and CAFs. Identification of the interaction between LINC01915, miR-92a-3p, KLF4, and CH25H was done. The effects of LINC01915, miR-92a-3p, and KLF4 on the angiogenesis, extracellular vesicle (EV) uptake by NFs, and activation of stromal cells were assessed using gain- or loss-of-function approaches. Xenograft mouse models were established to validate these in vitro findings in vivo. EVs were shown to stimulate NF proliferation, migration, and angiogenesis, as well as facilitate NF conversion into CAFs. CRC tissues and CAFs showed downregulated expression of LINC01915, which was associated with poor prognosis of patients. Moreover, employed LINC01915 inhibited tumor angiogenesis, CAF activation, and the uptake of tumor-derived EVs by NFs. Mechanistically, LINC01915 could competitively bind to miR-92a-3p and caused upregulation of the miR-92a-3p target KLF4 which, in turn, promoted the transcription of CH25H, leading to the suppressed uptake of EVs by NFs. The in vivo and in vitro experimental results showed that LINC01915 inhibited the uptake of CRC-derived EVs by NFs through the miR-92a-3p/KLF4/CH25H axis, thus arresting the angiogenesis and the conversion of NFs into CAFs and in turn prevent tumor growth. These data together supported the inhibiting role of LINC01915 in the conversion of NFs into CAFs triggered by the CRC-derived EVs and the ensuing tumor growth, which may be related to its regulation on the miR-92a-3p/KLF4/CH25H axis.

Analyzing the Effect of Vitronectin on Cell Growth and Mesenchymal-Epithelial Transition of Pulmonary Fibroblast Cells.

Vitronectin (VTN), a multifunctional glycoprotein, is involved in various biological and pathological processes. The purpose of this study was to explore the effect of VTN on mesenchymal-epithelial transition (MET) of pulmonary fibroblast cells. Lentivirus encoding for VTN-specific shRNA was constructed and infected into the cultured fibroblast WI-38 cells. Real-time PCR and Western blot were applied to examine the expression of VTN in WI-38 cells. MTT assay was used to assess cell proliferation. Western blot was conducted to examine the expression of MET-related and apoptosis-related proteins. The knockdown of VTN significantly inhibited the growth of WI-38 cells compared to the control group. Meanwhile, knockdown of VTN remarkably increased the expression of Bax and Caspase 3 compared with the control group. Furthermore, knockdown of VTN significantly promoted the expression of E-cadherin in comparison to control group. Knockdown of VTN promoted the expression of apoptosis-related factors, meanwhile, facilitated the MET process of fibroblast cells by regulating the expression of relevant factors. In sum, VTN performed a potential regulator in cell growth and MET of pulmonary fibroblast cells, which can be considered as a potential target for diagnose and therapy of relevant diseases.

Wound healing potential of human umbilical cord mesenchymal stem cell conditioned medium: An in vitro and in vivo study in diabetes-induced rats.

Background and Aim:Human umbilical cord mesenchymal stem cells (hUC-MSCs) and its conditioned medium (CM) promote wound healing. This study investigated the wound healing potential of hUC-MSC CM in vitro and in vivo using diabetic animal models.Materials and Methods:The CM from hUC-MSC CM prepared under hypoxic conditions (hypoxic hUC-MSC) was evaluated for stimulating rat fibroblast growth, collagen production (in vitro), and wound healing in animal models (in vivo). An excision wound on the dorsal side of the diabetes-induced rats was established, and the rats were randomly divided into non-treatment, antibiotic, and hypoxic hUC-MSC CM groups. The cell number of fibroblasts and collagen secretion was evaluated and compared among the groups in an in vitro study. By contrast, wound size reduction, width of re-epithelialization, and the collagen formation area were assessed and compared among the groups in an in vivo study.Results:CM under hypoxic conditions contained a higher concentration of wound healing-related growth factors. Hypoxic hUC-MSC CM could facilitate fibroblast cell growth and collagen synthesis, although not significant compared with the control group. Re-epithelialization and collagen production were higher in the hUC-MSC CM group than in the antibiotic and non-treatment groups.Conclusion:Hypoxic hUC-MSC CM possessed more positive effects on the wound healing process based on re-epithelialization and collagen formation than antibiotic treatment did.

Development of Si doped nano hydroxyapatite reinforced bilayer chitosan nanocomposite barrier membranes for guided bone regeneration

Guided Bone Regeneration (GBR) is a widely used process for the treatment of periodontal defects to prevent the formation of surrounding soft tissue at the periodontal defect and to provide hard tissue regeneration. Recently GBR designs have focused on the development of resorbable natural polymer-based barrier membranes due to their biodegradability and excellent biocompatibility. The aim of this study is to fabricate a novel bilayer nanocomposite membrane with microporous sublayer composed of chitosan and Si doped nanohydroxyapatite particles (Si-nHap) and chitosan/PEO nanofiber upper layer. Bilayer membrane was designed to prevent epithelial and fibroblastic cell migration and growth impeding bone formation with its upper layer and to support osteogenic cell bioactivity at the defect site with its sublayer. Microporous and nanofiber layers were fabricated by using freeze-drying and electrospinning techniques respectively. The effect of Si-nHap content on the morphological, mechanical and physical properties of the composites were investigated using SEM, AFM, micro-Ct, compression test, water uptake capacity and enzymatic degradation study. Antimicrobial properties of nanocomposite membranes were investigated with tube dilution and disk diffusion methods. In vitro cytotoxicity of bilayer membranes was evaluated. Saos-2 and NIH/3T3 proliferation studies were carried out on each layer. In vitro bioactivity of Saos-2 and NIH/3T3 cells were evaluated with ALP activity and hydroxyproline content respectively. Results showed that Si-nHap incorporation enhanced the mechanical and physical properties as well as controlling biodegradability of the polymer matrix. Besides, Si-nHap loading induced the bioactivity of Saos-2 cells by enhancing cell attachment, spreading and biomineralization on the material surface. Thus, results supported that designed bilayer nanocomposite membranes can be used as a potential biomaterial for guided bone regeneration in periodontal applications.

Antibacterial and Biocompatible Hydrogel Dressing Based on Gelatin- and Castor-Oil-Derived Biocidal Agent.

Favored antibacterial activity associated with excellent biocompatibility, mechanical durability, and exudate handling needs to be addressed by modern dressing to achieve the desired wound healing. This paper deals with developing a new green and facile approach to manufacturing nonleachable antibacterial gelatin-based films for wound dressing. Therefore, a reactive methoxy-silane-functionalized quaternary ammonium compound bearing a fatty amide residue originating from castor oil (Si-CAQ) was initially synthesized. The antibacterial dressings were then fabricated via sol-gel and condensation reactions of the mixture containing gelatin, Si-CAQ, (3-glycidyloxypropyl) trimethoxysilane, and poly(vinyl alcohol). By utilizing bioactive polymers as starting materials and eliminating organic solvents during the dressing preparation, desirable clinical safety could be ensured. The gelatin-based films presented appropriate mechanical properties, such as flexibility and strength, in both dried and hydrated states (tensile strength >6 MPa and elongation >100). It is due to the in situ generations of the inorganic silicon domain in the organic framework via the sol-gel cross-linking process. The prepared dressings exhibited desirable features, including excellent biocompatibility (cell viability >95%), proper wound-exudate-managing characteristics (equilibrium water contact (EWA) 280-350% and water vapor transmission rate (WVTR) 2040-2200 g/m2/day), fluid handling capacity (FHC) (3-3.35 g), as well as commendable hemocompatibility. The promising bactericidal activity of the dressing against Bacillus subtilis, methicillin-resistant Staphylococcus aureus, and Escherichia coli strains with a contact-killing efficacy of 100% could prevent infection development at the wounded area. As evaluated by the wound scratch assay, the desired fibroblast cell growth, migration, and proliferation indicated the capability of the dressing to facilitate the healing process by encouraging fibroblast cell migration to the damaged area. In vivo wound-healing results showed that the prepared biocidal dressing stimulates wound healing and enhances epithelialization, collagen maturation, and vascularization of wounds due to their antibacterial effects and accelerated cellular functions.

A Robust Protocol for Decellularized Human Lung Bioink Generation Amenable to 2D and 3D Lung Cell Culture

Decellularization efforts must balance the preservation of the extracellular matrix (ECM) components while eliminating the nucleic acid and cellular components. Following effective removal of nucleic acid and cell components, decellularized ECM (dECM) can be solubilized in an acidic environment with the assistance of various enzymes to develop biological scaffolds in different forms, such as sheets, tubular constructs, or three-dimensional (3D) hydrogels. Each organ or tissue that undergoes decellularization requires a distinct and optimized protocol to ensure that nucleic acids are removed, and the ECM components are preserved. The objective of this study was to optimize the decellularization process for dECM isolation from human lung tissues for downstream 2D and 3D cell culture systems. Following protocol optimization and dECM isolation, we performed experiments with a wide range of dECM concentrations to form human lung dECM hydrogels that were physically stable and biologically responsive. The dECM based-hydrogels supported the growth and proliferation of primary human lung fibroblast cells in 3D cultures. The dECM is also amenable to the coating of polyester membranes in Transwell™ Inserts to improve the cell adhesion, proliferation, and barrier function of primary human bronchial epithelial cells in 2D. In conclusion, we present a robust protocol for human lung decellularization, generation of dECM substrate material, and creation of hydrogels that support primary lung cell viability in 2D and 3D culture systems

Comparative Evaluation of Safety and Efficacy of a Novel Hyaluronic Acid-polynucleotide/Poly-L-lactic Acid Composite Dermal Filler

Poly-L-lactic acid (PLLA) is widely used in tissue engineering. The natural polymer hyaluronic acid (HA) shows excellent biocompatibility and affects cell signaling, proliferation, and differentiation. In addition, a polynucleotide (PN) induces cell growth of human skin fibroblasts and osteoblasts. In this study, we evaluated the properties, safety, and efficacy of a novel composite filler consisting of cross-linked HA with PN in combination with monodisperse PLLA microspheres manufactured using Inventage Lab Precision Particle Fabrication method. The composition of the filler and characteristics of the microspheres were examined via scanning electron microscopy, particle size analysis, gel permeation chromatography, and rheology and osmolality measurement. Additionally, safety and efficacy of HA-PN/PLLA composite filler were conducted in in vitro and in vivo. Analysis of PLLA microspheres revealed spherical surfaces and a narrower particle size distribution than that in PLLA filler. HA-PN/PLLA composite filler had higher viscosity and elasticity values and similar osmolality as compared to those of HA and PN fillers. The nontoxicity in in vitro and in vivo tests reflected that the composite filler may be safe for human use. In addition, the composite filler maintained a more stable volume than did HA filler for 24 weeks after administration in HWY/Slc hairless rats. Furthermore, the results support the effect of HA-PN/PLLA in restoring skin structure. Altogether, these data suggest that the novel composite filler might be a safe and effective option in terms of tissue integration, clinical management during delivery and high esthetic durability. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Attachment and Growth of Fibroblast Cells on Poly (2-Methoxyethyl Acrylate) Analog Polymers as Coating Materials

The regulation of adhesion and the subsequent behavior of fibroblast cells on the surface of biomaterials is important for successful tissue regeneration and wound healing by implanted biomaterials. We have synthesized poly(ω-methoxyalkyl acrylate)s (PMCxAs; x indicates the number of methylene carbons between the ester and ethyl oxygen), with a carbon chain length of x = 2–6, to investigate the regulation of fibroblast cell behavior including adhesion, proliferation, migration, differentiation and collagen production. We found that PMC2A suppressed the cell spreading, protein adsorption, formation of focal adhesion, and differentiation of normal human dermal fibroblasts, while PMC4A surfaces enhanced them compared to other PMCxAs. Our findings suggest that fibroblast activities attached to the PMCxA substrates can be modified by changing the number of methylene carbons in the side chains of the polymers. These results indicate that PMCxAs could be useful coating materials for use in skin regeneration and wound dressing applications.

The Effect of Biopolymer Coatings on Hernia Meshes in a Rat Model

Purpose: To improve biocompatibility and texture of hernia meshes has played a key role in tissue engineering for decades. Biopolymer (Polyethylenimine (PEI) and 3-Glycidoxypropyltrimethoxysilane (GOPS)) coating on Polypropylene (PP) and expanded Polytetrafluoroethylene (ePTFE) mesh showed promising results in fibroblast adhesion and cell growth in an invitro analysis. The objective of this animal study was to evaluate whether this may influence the incorporation into host tissue. Methods: 30 male Lewis rats were divided into 3 groups (n=10): Group 1: ePTFE/PEI, Group 2: ePTFE/GOPS, Group 3: PP/PEI. In each animal, a 3x0.5 cm coated mesh was implanted in the right rectus sheath in sublay position, the uncoated mesh was implanted on the left equally. After 90 days, the rats were sacrificed and each side of the rectus sheath was analyzed separately for adhesions and mechanical strength. Histopathological assessment included Gieson’s stain and haematoxylin-eosin staining. The Wilcoxon test was used for statistical analyses. Results: The GOPS-coated ePTFE tends to cause more adhesions. There was no significant difference in the mechanical strength within and between the groups, but the PEI-coated polypropylene was significantly less extendible (p<0.05) compared to the uncoated PP. In group 2, Gieson’s stain showed a significantly lower surrounding tissue reaction of foreign-body giant cells and scar tissue around the PEI-coated mesh compared to the uncoated ePTFE (p<0.05). Conclusions: It is possible to coat surgical mesh devices with biopolymers. They do not lead to a lack of mechanical strength. The GOPS-coating did not show any general positive effect on the biocompatibility of meshes. The PEIcoating resulted in a lower surrounding tissue reaction and in a less extendible abdominal wall and should therefore be investigated further.

Dermal fibroblast cells interactions with single and triple bacterial-species biofilms.

Polymicrobial biofilm leads to wound healing delay. We set up an in vitro co-culture model of single- and triple-species biofilms of Staphylococcus aureus, Pseudomonas aeruginosa and Enterococcus faecalis with dermal fibroblast to assess the fibroblast response against to the different biofilms. Scratch and viability assays and biofilm cell quantifications were performed by WST-1, CLSM and plating method, respectively. Quorum sensing-related gene expression levels in P. aeruginosa and E. faecalis were analysed by reverse-transcriptase PCR. The immune responses of cells against S. aureus, P. aeruginosa and E. faecalis biofilms were measured by cytokine and matrix metalloproteinase analyzes. The influence of biofilm soluble factors on fibroblasts was also determined. After 24h, triple-species biofilm cells caused the removal of the fibroblasts from the surfaces indicating the negative synergistic effect of three species. After co-cultures, twenty-five cytokines were significantly increased in fibroblast cells compared to control. Compared to other strains, the most important cytokine, chemokine and growth factors increased was observed in P. aeruginosa co-cultures with fibroblast. While the expressions of fsrB and gelE genes were significantly upregulated in E. faecalis biofilm cells cultured with fibroblast cells, no significant difference was observed in P. aeruginosa. The wound healing and cell growth of fibroblasts were disrupted more aggressively in the presence of P. aeruginosa and triple-species biofilm cells. P. aeruginosa generally induced a stronger immune response in the fibroblasts than E. faecalis and S. aureus.

Examination of lipid profiles in abdominal fascial healing using MALDI-TOF to identify potential therapeutic targets

BackgroundFailure of fascial healing in the abdominal wall can result in incisional hernia, which is one of the most common complications after laparotomy. Understanding the molecular healing process of abdominal fascia may provide lipid markers of incisional hernia or therapeutic targets that allow prevention or treatment of incisional hernias. PurposeThis study aims to investigate temporal and in situ changes of lipids during the normal healing process of abdominal fascia in the first postoperative week. MethodsOpen hemicolectomy was performed in a total of 35 Wistar rats. The midline fascia was closed identically for all rats using a single continuous suturingtechnique. These animals were sacrificed with equal numbers (n = 5) at each of 7-time points (6, 12, 24, 48, 72, 120, and 168 h. The local and temporal changes of lipids were examined with mass spectrometry imaging and correlated to histologically scored changes during healing using hematoxylin and eosin staining. ResultsTwo phosphatidylcholine lipid species (PC O-38:5 and PC 38:4) and one phosphatidylethanolamine lipid (PE O-16:1_20:4) were found to significantly correlate with temporal changes of inflammation. A phosphatidylcholine (PC 32:0) and a monosialodihexosylganglioside (GM3 34:1;2) were found to correlate with fibroblast cell growth. ConclusionGlycerophospholipids and gangliosides are strongly involved in the normal healing process of abdominal fascia and their locally fluctuating concentrations are considered as potential lipid markers and therapeutic targets of fascial healing.

Efficacy of chitinase-3-like protein 1 as an invivo bone formation predictable marker of maxillary/mandibular bone marrow stromal cells.

IntroductionMaxillary/mandibular bone marrow stromal cells (MBMSCs) are a useful cell source for bone regeneration in the oral and maxillofacial region. To further ensure the clinical application of MBMSCs in bone regenerative therapy, it is important to determine the bone formation capacity of MBMSCs before transplantation. The aim of this study is to identify the molecular marker that determines the in vivo bone formation capacity of MBMSCs.MethodsThe cell growth, cell surface antigens, in vitro and in vivo bone formation capacity of MBMSCs were examined. The amount of chitinase-3-like protein 1 (CHI3L1) secreted into the conditioned medium was quantified. The effects of CHI3L1 on the cell growth and osteogenic differentiation potential of MBMSCs and on the cell growth and migration of vascular endothelial cells and fibroblasts were examined.ResultsThe cell growth, and in vitro and in vivo bone formation capacity of the cells treated with different conditions were observed. MBMSCs that secreted a large amount of CHI3L1 into the conditioned medium tended to have low in vivo bone formation capacity, whereas MBMSCs that secreted a small amount of CHI3L1 had greater in vivo bone formation capacity. CHI3L1 promoted the migration of vascular endothelial cells, and the cell growth and migration of fibroblasts.ConclusionOur study indicates that the in vitro osteogenic differentiation capacity of MBMSCs and the in vivo bone formation capacities of MBMSCs were not necessarily correlated. The transplantation of high CHI3L1 secretory MBMSCs may suppress bone formation by inducing fibrosis at the site. These results suggest that the CHI3L1 secretion levels from MBMSCs may be used as a predictable marker of bone formation capacity in vivo.

A Study of Combining Elastin in the Chitosan Electrospinning to Increase the Mechanical Strength and Bioactivity.

While electrospun chitosan membranes modified to retain nanofibrous morphology have shown promise for use in guided bone regeneration applications in in vitro and in vivo studies, their mechanical tear strengths are lower than commercial collagen membranes. Elastin, a natural component of the extracellular matrix, is a protein with extensive elastic property. This work examined the incorporation of elastin into electrospun chitosan membranes to improve their mechanical tear strengths and to further mimic the native extracellular composition for guided bone regeneration (GBR) applications. In this work, hydrolyzed elastin (ES12, Elastin Products Company, USA) was added to a chitosan spinning solution from 0 to 4 wt% of chitosan. The chitosan–elastin (CE) membranes were examined for fiber morphology using SEM, hydrophobicity using water contact angle measurements, the mechanical tear strength under simulated surgical tacking, and compositions using Fourier-transform infrared spectroscopy (FTIR) and post-spinning protein extraction. In vitro experiments were conducted to evaluate the degradation in a lysozyme solution based on the mass loss and growth of fibroblastic cells. Chitosan membranes with elastin showed significantly thicker fiber diameters, lower water contact angles, up to 33% faster degradation rates, and up to seven times higher mechanical strengths than the chitosan membrane. The FTIR spectra showed stronger amide peaks at 1535 cm−1 and 1655 cm−1 in membranes with higher concentrated elastin, indicating the incorporation of elastin into electrospun fibers. The bicinchoninic acid (BCA) assay demonstrated an increase in protein concentration in proportion to the amount of elastin added to the CE membranes. In addition, all the CE membranes showed in vitro biocompatibility with the fibroblasts.

Designing hybrid nanofibers based on keratin-poly (vinyl alcohol) and poly (Ɛ-caprolactone) for application as wound dressing

In this study, the production of hybrid scaffolds containing keratin/polyvinyl alcohol (Ker/PVA) and poly (Ɛ-caproactone) (PCL) for application in skin regeneration has been investigated. In the first step, the extraction of keratin from wool fibers was done, and then electrospinning process was used to fabricate hybrid nanofibers. Ker/PVA blend solution was extruded from one syringe and poly(ε-caprolactone) solution from the other one and hybrid nanofibers were gathered onto a rotary drum collector. The effect of different ratios of Ker/PVA (30:70), (50:50), and (70:30) with PCL were studied on the morphology, hydrophilicity and mechanical features of the scaffolds. The Ker/PVA (50:50)-PCL nanofibers presented an appropriate modulus and mechanical strength similar to the natural skin. These scaffolds possessed high levels of hydrophilicity, which improved cell-scaffold adhesion and increased the growth and proliferation of fibroblast cells. Keratin based nanofibers demonstrated antibacterial characteristic against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus.

Development of Tunable Silk Fibroin/Xanthan Biopolymeric Scaffold for Skin Tissue Engineering Using L929 Fibroblast Cells

Skin acts as protective barrier against a number of factors such as dust, opportunistic microbial and viral infections, regulates body temperature and waste discharge. Fibroblast cell population plays an important role in development of skin architecture. A scaffold having capability to support and enhance fibroblast growth is a viable option for wound dressing material which can shorten the time for wound to heal. In this work, Silk Fibroin (SF) and Xanthan (Xa) were blended in three ratios 80 SF: 20 Xa (SFX82), 60 SF: 40 Xa (SFX64), and 50 SF: 50 Xa (SFX55) to create SF/Xa scaffold. Miscibility and other physicochemical properties of SF/Xa scaffold are functions of blending ratios and blend with the ratio 80 SF: 20 Xa has the highest miscibility. Thermal properties of SF/Xa blends are a function of miscibility with SFX82 having superior thermal properties of all fabricated scaffolds. The porosity of SF/Xa scaffolds is in the range of 67% to 50%, with pore size of 58.1 µm–45.5 µm, water uptake capacity of 92%–86%, and surface roughness of 49.95 nm–385 nm. SFX82 shows highest growth rate of L929 fibroblast cells indicating its superiority over other scaffolds for providing biological cues for the growth and proliferation of fibroblastic cells in natural environment. SFX82 scaffold is found to be most suitable for fibroblastic cells thereby enhancing the tissue regeneration at wound site.

Electrospun Skin Tissue Engineering Scaffolds Based on Polycaprolactone/Hyaluronic Acid/L-ascorbic Acid

Skin tissue engineering is an evolving method to reconstruct skin damages caused by disease, burn or trauma. In skin tissue engineering, scaffolds should prepare three-dimensional structure for skin cells. Electrospinning technique has been widely applied for producing nano/micro-scale fiber scaffolds in tissue engineering. In this study, electrospun scaffolds based on polycaprolactone (PCL) and hyaluronic acid (HA) containing L-ascorbic acid (AA) were fabricated. Morphology, contact angle, functional groups, biodegradability and drug release of the scaffolds were evaluated. L929 fibroblast cells seeded on nanofibrous scaffolds and cell attachment and viability were evaluated as well. According to the results, the fibers diameter were less than 180 nm and by adding hyaluronic acid, the hydrophilicity of scaffolds increased and degradation rate was adjusted. The encapsulation efficiency and successful release of ascorbic acid in nanofibrous scaffolds were demonstrated. According to the results, the cell growth, proliferation and adhesion of L929 fibroblast cells on the PCL/HA/AA scaffolds were enhanced in comparison with the PCL scaffold. Moreover, PCL/HA (80:20) containing 40 mg of AA nanofibrous scaffold could be potentially applied for skin tissue engineering.

CDC25B induces cellular senescence and correlates with tumor suppression in a p53-dependent manner

The phosphatase cell division cycle 25B (Cdc25B) regulates cell cycle progression. Increased Cdc25B levels are often detected in cancer cell lines and human cancers and have been implicated in contributing to tumor growth, potentially by providing cancer cells with the ability to bypass checkpoint controls. However, the specific mechanism by which increased Cdc25B impacts tumor progression is not clear. Here we analyzed The Cancer Genome Atlas (TCGA) database and found that patients with high CDC25B expression had the expected poor survival. However, we also found that high CDC25B expression had a p53-dependent tumor suppressive effect in lung cancer and possibly several other cancer types. Looking in more detail at the tumor suppressive function of Cdc25B, we found that increased Cdc25B expression caused inhibition of cell growth in human normal fibroblasts. This effect was not due to alteration of specific cell cycle stage or inhibition of apoptosis, nor by induction of the DNA damage response. Instead, increased CDC25B expression led cells into senescence. We also found that p53 was required to induce senescence, which might explain the p53-dependent tumor suppressive function of Cdc25B. Mechanistically, we found that the Cdc25B phosphatase activity was required to induce senescence. Further analysis also found that Cdc25B stabilized p53 through binding and dephosphorylating p53. Together, this study identified a tumor-suppressive function of Cdc25B that is mediated through a p53-dependent senescence pathway.