Zobrazení zdroje stránky Salazarlowe7690

Cytotoxicity tests revealed that the samples were non-toxic. Despite none of the samples having been raised up through cell adhesion tests, cell differentiation revealed promising results for the Ta-CaP.Porous scaffolds have been widely used for bone tissue engineering (BTE), and the pore structure of scaffolds plays an important role in osteogenesis. Silk fibroin (SF) is a favorable biomaterial for BTE due to its excellent mechanical property, biocompatibility, and biodegradation, but the lack of cell attachment sites in SF chemical structure resulted in poor cell-material interactions. In this study, SF scaffolds were coated with fibronectin/gelatin (Fn/G) to improve cell adhesion. Furthermore, the effect of pore size in Fn/G coated SF scaffolds on osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) were investigated in vitro. Scaffolds with average pore diameters of 384.52, 275.23, and 173.8 μm were prepared by salt leaching method, labelled as Large, Medium, and Small group. Porcine BMSCs were seeded on scaffolds and cultured in osteogenic medium for 21 days to evaluate cell proliferation, alkaline phosphatase (ALP) activity, calcium deposition, gene expression of osteogenic markers, and histological performance. The results showed Fn/G coating effectively improved cell adhesion on SF scaffolds. Cell metabolic rate in each group increased significantly with time, but there was no statistical difference at each time point among the three groups. On day 21, ALP/DNA and calcium/DNA in the Small group were significantly higher than those in the Large group. Among the three pore sizes, the Small group showed higher mRNA expression of COl I on day 7, OPN on day 14, and OCN on day 21. Immunohistochemical staining on day 21 showed that Col I and OCN in Small group were more highly expressed. In conclusion, the Fn/G coated SF scaffolds with a mean pore diameter of 173.8 μm was optimal for osteogenic differentiation of BMSC in vitro.The essentiality of macrophages for biomaterial-mediated osteogenesis has been increasingly recognized. However, it is still unclear what is the specific role and molecular mechanisms of macrophages and material properties in the regulation of osteogenesis. As an interdisciplinary field exploring the cross-talk between immune and skeletal systems, osteoimmunology has shifted the perspective of bone substitute materials from immunosuppressive materials to immunomodulatory materials. To fabricate an immunomodulatory Ti implant, alginate/chitosan multilayer films were fabricated on the surface of titania nanotubes (TNTs) to control the release of an anti-inflammatory cytokine interleukin (IL)-4 according to our previous work. The osteogenic effects and regulation mechanisms of the immunomodulatory Ti implants were investigated in vitro in different BMSCs culture modes. Alginate/chitosan multilayer-coated samples (with or without IL-4 loading) showed better direct osteogenic ability than TNTs by promoting biomineralization and up-regulating osteogenic gene expression (BMP1α, ALP, OPN, OCN) of BMSCs. Notably, material-induced macrophage polarization, M1 and M2, enhanced early and mid-stage osteogenesis of BMSCs via distinct pathways M1 activated both BMP6/SMADs and Wnt10b/β-catenin pathways; while M2 activated TGF-β/SMADs pathway. Material surface properties dominated in regulating late osteogenesis probably due to the surface chemical composition (alginate, chitosan and Ca2+, etc.). Due to synergistic effects of material-induced inflammatory microenvironment and material surface properties, IL-4-loaded samples exhibited superior osteogenic capability through co-activation of three signaling pathways. The in vivo studies in rat bone defect model revealed that IL-4-loaded immunomodulatory implants successfully achieved macrophage phenotypic transition from pro-inflammatory M1 to anti-inflammatory M2 and subsequently improved new bone formation.The development of theranostic platforms combining surface-enhanced Raman spectroscopy (SERS) imaging with NIR-stimulated photothermal therapy (PTT) is of utmost importance for the precise diagnosis and selective treatment of cancers, especially in superficial solid tumors. For this purpose, a versatile theranostic nanoprobe of liposomal layer-coated Au nanocages (AuNCs) was decorated with an anti-MUC18 single-chain antibody (scFv). 4-mercapto benzoic acid (p-MBA)-labeled AuNCs (p-AuNCs) were coated by a liposomal layer (p-AuNCs@lip), followed by conjugating anti-MUC18 scFv via post-insertion method to form immuno-liposomal layer-coated AuNCs (p-AuNCs@scFv-lip). Physicochemical characterizations of the p-AuNCs@scFv-lip were investigated by transmission electron microscopy (TEM) and UV-vis and Raman spectroscopy. Furthermore, the targeting ability and theranostic efficiency of the nanoprobe were evaluated for specific diagnosis and treatment of cancerous melanoma cells by flow cytometry, SERS mapping, and live/dead assay. The formation of lipid layer on p-AuNCs surface was confirmed by TEM imaging. After decorating the liposomal layer with scFv, a relevant red shift was observed in the UV-vis spectrum. [https://www.selleckchem.com/products/pf-04691502.html PF-04691502 clinical trial] Moreover, p-AuNCs@lip presented characteristic peaks in the Raman spectrum, which exhibited only a minor change after scFv conjugation (p-AuNCs@scFv-lip). Interestingly, the cellular uptake of AuNCs@scFv-lip by A375 cell line (MUC18+) showed a 24-fold enhancement compared with SKBR3 cells (MUC18-). AuNCs@scFv-lip specifically identified A375 cells from SKBR cells via SERS mapping and effectively killed A375 cells through the PTT mechanism. Taken together, this theranostic platform can provide a promising tool for both in situ diagnosis and remote-controlled thermal ablation of cancer cells.Conventional electrospun small diameter vascular grafts have a random fiber orientation. In order to achieve mechanical characteristics similar to a native blood vessel, a controllable fiber orientation is of interest. In this study the electrospinning jet was directly controlled by means of an auxiliary, changeable electrostatic field, so that the fibers could be deposited in adjustable orientations. Prostheses with circumferentially, axially, fenestrated and randomly aligned fibers were electrospun on Ø2mm mandrels out of a thermoplastic polyurethane (PUR) and a polylactid acid (PLLA). The impact of the materials and the various preferential fiber orientations on the resulting biomechanics was investigated and compared with that of the native rat aorta in quasistatic and dynamic hoop tensile tests. The test protocol included 3000 dynamic loading cycles in the physiological blood pressure range and ended with a quasistatic tensile test. Any orientation of the fibers in a particular direction resulted in a significant reduction in scaffold porosity for both materials. The standard randomly oriented PUR grafts showed the highest compliance of 29.7 ± 5.5 [%/100 mmHg] and were thus closest to the compliance of the rat aortas, which was 37.2 ± 6.5 [%/100 mmHg]. The maximum tensile force was increased at least 6 times compared to randomly spun grafts by orienting the fibers in the circumferential direction. During the 3000 loading cycles, creeping of the native rat aorta was below 1% whereas the electrospun grafts showed creeping up to 2.4 ± 1.2%. Although the preferred fiber orientations were only partially visible in the scanning electron micrographs, the mechanical effects were evident. The investigations suggest a multi-layer wall structure of the vascular prosthesis, since none of the preferred fiber directions and the materials used could imitate the typical j-shaped mechanical characteristics of the rat aorta.The pre-mature release of therapeutic cargos in the bloodstream or off-target sites is a major hurdle in drug delivery. However, stimuli-specific drug release responses are capable of providing greater control over the cargo release. Herein, various types of nanocarriers have been employed for such applications. Among various types of nanoparticles, mesoporous silica nanoparticles (MSNPs) have several attractive characteristics, such as high loading capacity, biocompatibility, small size, porous structure, high surface area, tunable pore size and ease of functionalization of the external and internal surfaces, which facilitates the entrapment and development of stimuli-dependent release of drugs. MSNPs could be modified with such stimuli-responsive entities like nucleic acid, peptides, polymers, organic molecules, etc., to prevent pre-mature cargo release, improving the therapeutic outcome. This controlled drug release system could be modulated to function upon extracellular or intracellular specific stimuli, including pH, enzyme, glucose, glutathione, light, temperature, etc., and thus provide minimal side effects at non-target sites. This system has great potential applications for the targeted delivery of therapeutics to treat clinically challenging diseases like cancer. This review summarizes the synthesis and design of stimuli-responsive release strategies of MSNP-based drug delivery systems along with investigations in biomedical applications.Surface treatment of biomaterials could enable reliable and quick cellular responses and accelerate the healing of the host tissue. Here, a series of calcium phosphates (CaPs) were surface treated by hydrogen peroxide (H2O2) and the treatment effects were physicochemically and biologically evaluated. For this aim, as-synthesized CaPs doped with strontium (Sr2+), iron (Fe2+), silicon (Si4+), and titanium (Ti4+) ions were sonicated in H2O2 media. The results showed that the specific surface area and zeta potential values of the surface-treated CaPs were increased by ~50% and 25%, respectively. Moreover, the particle size and the band-gap (Eg) values of the surface-treated CaPs were decreased by ~25% and ~2-10%, respectively. The concentration of oxygen vacancies was increased in the surface-treated samples, which was confirmed by the result of ultraviolet (UV), photoluminescence (PL), Commission Internationale de l'éclairage (CIE 1931), and X-ray photoelectron spectroscopy (XPS) analyses. In vitro cellular assessments of surface-treated CaPs exhibited an improvement in cytocompatibility, reactive oxygen species generation (ROS) capacity, bone nodule formation, and the migration of cells up to ~8%, 20%, 35%, and 13%, respectively. Based on the obtained data, it can be stated that improved physicochemical properties of H2O2-treated CaPs could increase the ROS generation and subsequently enhance the biological activities. In summary, the results demonstrate the notable effect of the H2O2 surface treatment method on improving surface properties and biological performance of CaPs.Nanomaterials hold promise as a straightforward approach for enhancing the performance of bioactive compounds in several healthcare scenarios. Indeed, nanoencapsulation represents a valuable strategy to preserve the bioactives, maximizing their bioavailability. Here, a nanoencapsulation strategy for the treatment of nonalcoholic fatty liver disease (NAFLD) is presented. NAFLD represents the most common chronic liver disease in Western societies, and still lacks an effective therapy. Hydroxytyrosol (HT), a naturally occurring polyphenol, has been shown to protect against hepatic steatosis through its lipid-lowering, antioxidant and anti-inflammatory activities. However, the efficient delivery of HT to hepatocytes remains a crucial aspect the design of smart nanogels appears as a promising tool to promote its intracellular uptake. In this paper, we disclose the synthesis of nanogel systems based on polyethylene glycol and polyethyleneimine which have been tested in an in vitro model of hepatic steatosis at two different concentrations (0.