Hansenberry2854
In this work, we show synthesis that leads to thermoreponsive poly-N-isopropyl acrylamide (pNIPAM) nanogels with sizes below 100 nm, irrespectively of the surfactant to crosslinker ratio. We also show that in many environments the temperature induced pNIPAM collapse at Lower Critical Solution Temperature (LCST) of 32.5 °C is accompanied by gel nanoparticles' aggregation. Thus, the proper information on the nanoparticle (NP) structure and deswelling can be obtained only if the routinely measured hydrodynamic radius is supplemented by information on the molecular weight, which can be obtained from the intensity of scattered light. We measured the dynamics and reversibility of the deswelling and subsequent aggregation processes. Furthermore, we show that the highly concentrated pNIPAM gel NPs reversibly form bulk hydrogel networks of varied interconnected porous structure. We show, that in case of drying pNIPAM gel NPs above the LCST, it is possible to obtain films with 20-fold increase in storage modulus (G') compared to hydrogel networks measured at room temperature. They exhibit temperature hysteresis behavior around LCST of 32.5 °C similar to pNIPAM films. Finally, we show that these hydrogel films, lead to extended proliferation of cells across three different types fibroblast, endothelial and cancer cells. Additionally, none of the films exhibited any cytotoxic effects. Our study brings new insights into physicochemical characterization of pNIPAM gel NPs and networks behavior in realistic conditions of in vitro measurements, especially by means of dynamic light scattering as well as final unique properties of both gel NPs and formed porous films for possible tissue engineering applications.Three-dimensional (3D) printing technology is serving as a promising approach of fabricating titanium (Ti) and its alloys used for bone tissue engineering. However, the biological inertness nature of Ti material limits its capability to bind directly with the bone tissue. This paper aims to enhance the bioactivity and osteogenesis of 3D printed Ti-6Al-4V implants by constructing a hierarchical micro/nano-topography on the surface. Ti-6Al-4V implants were prepared by the electron beam melting (EBM) technique. A method combining ultrasonic acid etching with anodic oxidation is proposed for surface modification of EBM Ti-6Al-4V implants in this study. The acid etching step was to remove any existent residual powders on the implant's surface and construct micro-pits and -grooves on the EBM microrough surface. Nanotube arrays with a diameter of 40-50 nm were superimposed on the micro-structured substrate via anodic oxidation. The results of in vitro experiments showed that the hierarchical micro/nano-structured suIFICANCE Traditional titanium implants have the nature of biological inertness, which limits their capability to bind directly with the bone tissue. The failure of implants after couple of years of implantation will cause huge pain to the patients. In this work, a surface modification method for 3D printed implants was developed to construct a hierarchical micro/nano-structure. Through the in vitro and in vivo experiments, we proved that this hierarchical micro/nano-structure induced a better promotion effect on osteoblast proliferation and differentiation comparing with untreated surface or polished surface, and was also capable of bolstering the new bone formation, suggesting a potent strategy to improve the biological properties of 3D printed titanium implants. The work is expected to accelerate the application of 3D printed orthopedic and dental implants in clinics.Motivated by the need for self-disinfecting materials that can be used to reduce the surface transmission of harmful microbes to healthy hosts, here we prepared a photodynamic antimicrobial membrane comprised of electrospun cellulose diacetate (CA) microfibers into which the photosensitizer protoporphyrin IX (PpIX) was in situ embedded. The resultant porous PpIX-embedded CA (PpIX/CA) microfibrous membranes were prepared with two different photosensitizer loadings 5 and 10 wt% PpIX with respect to CA (85 and 170 nmol PpIX/mg membrane, respectively). The singlet oxygen (1O2) generated by the embedded photosensitizer was confirmed by electron paramagnetic resonance spectroscopic studies through generation of the TEMPO radical, and its photooxidation efficiency was further investigated using potassium iodide as a model substrate. Antibacterial photodynamic inactivation studies showed that the PpIX/CA membrane achieved a 99.8% reduction in Gram-positive S. aureus after illumination (Xe lamp, 65 ± 5 mW/cm2, λ ≥ 420 nm; 30 min), with a lower level of reduction (86.6%) for Gram-negative E. coli. Potentiation with potassium iodide was found to be an effective way to further enhance the antimicrobial efficacy of the PpIX/CA microfibrous membrane, achieving 99.9999% (6 log units) inactivation of both S. aureus and E. coli in the presence of 25 and 100 mM KI, respectively. These findings indicate that the electrospun CA microfibrous membrane is an ideal matrix for a photosensitizer such as PpIX to be embedded and effectively sensitized upon visible light illumination, and its antimicrobial photodynamic inactivation efficiency could be strongly enhanced with the increased KI addition, showing a promising future for its use in pathogen transmission defensive materials.Two core-double-shell pH-sensitive nanocarriers were fabricated using Fe3O4 as magnetic core, poly(glycidyl methacrylate-PEG) and salep dialdehyde as the first and the second shell, and doxorubicin as the hydrophobic anticancer drug. https://www.selleckchem.com/products/deferiprone.html Two nanocarriers were different in the drug loading steps. The interaction between the first and the second shell assumed to be pH-sensitive via acetal cross linkages. The structure of nanocarriers, organic shell loading, magnetic responsibility, morphology, size, dispersibility, and drug loading content were investigated by IR, NMR, TG, VSM, XRD, DLS, HRTEM and UV-Vis analyses. The long-term drug release profiles of both nanocarriers showed that the drug loading before cross-linking between the first and second shell led to a more pH-sensitive nanocarrier exhibiting higher control on DOX release. Cellular toxicity assay (MTT) showed that DOX-free nanocarrier is biocompatible having cell viability greater than 80% for HEK-293 and MCF-7 cell lines. Besides, high cytotoxic effect observed for drug-loaded nanocarrier on MCF-7 cancer cells. Cellular uptake analysis showed that the nanocarrier is able to transport DOX into the cytoplasm and perinuclear regions of MCF-7 cells. In vitro hemolysis and coagulation assays demonstrated high blood compatibility of nanocarrier. The results also suggested that low concentration of nanocarrier have a great potential as a contrast agent in magnetic resonance imaging (MRI).Selective delivery of drugs to damaged tissues favorable to reduce the side effects while enhancing the therapeutic efficacy. The purpose of the present study was the design and synthesis of multi-targeted nanoparticles for co-delivery of both drug and nucleic acid to cancer cells. In this study biocompatible compounds such as chitosan, polyethylene glycol (PEG), polycaprolactone (PCL), folic acid (FA) and glucose (Glu) were used to synthesize the FA-PEG-Chitosan-PCL-Chitosan-PEG-FA (FPCP) and Glu-PEG-Chitosan-PCL-Chitosan-PEG-Glu (GPCP) copolymers. Then, paclitaxel (PTX), oleic acid-coated FeCO nanoparticles (FeCO-OA) and 6-carboxy-fluorescein phosphoramidate (FAM)-labeled siRNA (siRNA-FAM) were encapsulated into either FPCP or GPCP, or both FPCP and GPCP (GFPCP), using the solvent evaporation technique. In vitro and in vivo biocompatibility and drug delivery efficiency of FPCP/FeCO-OA/PTX, GPCP/FeCO-OA/PTX and GFPCP/FeCO-OA/PTX nanoparticles were determined by recording the MTT assay, weight loss and tumor teractions between different amphipathic copolymers in appropriate is an efficient and easy technique to synthesize complex and multifunctional nanoparticles.Copper is well known for its multifunctional biological effects including antibacterial and angiogenic activities, while silicon-containing bioceramic has proved to possess superior biological properties to hydroxyapatite (HA). In this work, CuO was introduced to silicocarnotite (Ca5(PO4)2SiO4, CPS) to simultaneously enhance its mechanical and antibacterial properties, and its cytocompatibility was also evaluated. Results showed that CuO could significantly facilitate the densification process of CPS bioceramic through liquid-phase sintering. The bending strength of CPS with the addition of 3.0 wt% CuO improved from 29.2 MPa to 63.4 MPa after sintered at 1200 °C. Moreover, Cu-CPS bioceramics demonstrated superior in vitro antibacterial property against both S. aureus and E. coli strains by destroying their membrane integrity, and the antibacterial activity augmented with CuO content. Meanwhile, the released Cu ions from Cu-CPS bioceramics could promote the proliferation of human umbilical vein endothelial cells (HUVECs), and the in vitro cytocompatibility exhibited concentration dependence on Cu ions. These suggest that Cu-CPS bioceramics might be promising candidates for bone tissue regeneration with an ability to prevent postoperative infections.A simple, inexpensive in situ oxidative polymerization of aniline and pyrrole using ammonium persulfate (APS) as oxidant and hydrochloric acid (HCl) as dopant has been used to synthesize a hybrid (PAni-Co-PPy)@TiO2 nanocomposite with titanium oxide (TiO2) nanoparticles (NPs) wrapped into (PAni-Co-PPy) copolymer. The synthesized nanocomposite has been shown with higher oxygen reduction reactions (ORR) as an excellent cathode material for higher performance in the complex of (PAni-Co-PPy)+/TiO2(O-). The charge transport phenomenon between TiO2 and (PAni-Co-PPy)+ were found adequate with subsequent delocalization of electron/s at PAni and PPy. The self-doping nature of TiO2 (O-) played a vital role in oxygen adsorption and desorption process. With higher electrical conductivity and surface area, these were tested in microbial fuel cells (MFCs) for ORRs at cathode. This yielded a relatively higher current and power density output as compared to PAni@TiO2, PPy@TiO2, and commercially available Pt/C cathode catalysts in MFC system. In overall, the prepared (PAni-Co-PPy)@TiO2 nano-hybrid cathode delivered ~2.03 fold higher power density as compared to Pt/C catalyst, i.e. ~987.36 ± 49 mW/m2 against ~481.02 ± 24 mW/m2. The properties of electro-catalysts established an improved synergetic effect between TiO2 NPs and (PAni-Co-PPy). In effect, the enhanced surface area and electrochemical properties of the prepared (PAni-Co-PPy)@TiO2 nano-hybrid system is depicted here as an effective cathode catalyst in MFCs for improved performance.The enzymatic oxidation of glucose to produce reactive oxygen species (ROS) provides honey with antimicrobial efficacy. This mechanism offers an alternative to traditional antibiotics; however, topical use of honey is limited due to its adherent and highly viscous properties. This study aims to overcome these issues by engineering a powder-based system that eases delivery and offers in situ activation of ROS. Starch based drying agents were utilised to enable freeze drying of a medical honey, with methylated-β-cyclodextrin (MCD) enabling the highest active incorporation (70%) while still producing a free-flowing powder. Addition of a superabsorbent, sodium polyacrylate (≤40%) was shown to facilitate in situ gelation of the powder, with an absorption capacity of up to 120.7 ± 4.5 mL g-1. Promisingly efficacy of the optimised superabsorbent powder was demonstrated in vitro against several clinically relevant Gram-negative and Gram-positive bacteria (Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa).