查看更多>>摘要：Abstract A series of amphiphilic block and random copolymers based on phenylboronic acid pinacol ester were synthesized via reversible addition–fragmentation chain transfer polymerization. The obtained copolymers can self-assemble in aqueous solution into stable block copolymer nanoparticles and random nanoparticles with sizes of 116.1–158.6 and 126.3–187.0?nm, respectively. All nanoparticles showed hydrogen peroxide (H2O2) sensitivity, and the random copolymer nanoparticles presented faster responsiveness to H2O2 than did those derived from block copolymers. Berberine (BBR) can be effectively encapsulated into block and random copolymer nanoparticles with loading capacity of 7.6%–9.1% and 7.3%–8.9%, respectively. The BBR release can be controlled in an H2O2 medium. For the random copolymer nanoparticles, the release rate of BBR was faster and the cumulative release amounts in response to H2O2 were higher over 48?h. The BBR cumulative release amount in the H2O2 medium for the block and random copolymer nanoparticles was 62.2%–70.2% and 68.6%–80.4%, respectively. Moreover, good biocompatibility was observed for the BBR-loaded block and random copolymer nanoparticles. BBR and BBR-loaded nanoparticles can improve Glut4 translocation to the cell membrane and promote glucose transport into cells. BBR-loaded nanoparticles can decrease the blood glucose levels in diabetic rats over 15?days. These results imply that the different chain formulation of block and random copolymers affects the H2O2 responsiveness and that the two kinds of nanoparticles exhibit potential application as novel vehicles for BBR delivery to regulate blood glucose levels.
查看更多>>摘要：Abstract To overcome problems associated with topical delivery of tacrolimus (TCS), a thermoresponsive in situ gel system containing pluronic F127 (PL), and chitosan (CS) was developed, to enhance the precorneal retention, and to sustain the release of the drug. The PL-CS in situ gel was optimized using a 2-factor-3-level central composite experimental design by selecting the concentration of PL and CS as independent variables while gelation time, gelation temperature, and spreadability as dependent variables. The optimized formulation was developed using 22.5?g PL and 0.3?g CS, gels at 33.6?°C, in 22.93?s, and showed the spreadability of 6.2?cm. In vitro studies conducted for the optimized gel revealed the sustained release of TCS (81.73% in 4?h) and improved corneal permeation (74.13% in 4?h), compared with TCS solution. The mechanism of release of TCS followed the Higuchi model with Fickian diffusion transport. Further, histopathology and HET-CAM studies revealed that the developed gel was non-irritating and safe for ocular administration.
查看更多>>摘要：Abstract The purpose of this study was to develop a novel drug-polymer conjugation (mPEG-b-PCL-DOX) and study on its toxicity, bio-safety, and in?vitro antitumor activity of mPEG-b-PCL-DOX. The polymer methoxy poly(ethylene glycol)-block-poly(ε-caprolactone) (mPEG-b-PCL) was prepared by ring-opening polymerization. Then, succinic anhydride was reacted with mPEG-b-PCL via esterification reaction to produce mPEG-b-PCL-COOH. Finally, the polymer mPEG-b-PCL-DOX was obtained by conjugating DOX to mPEG-b-PCL-COOH by amidation. The Fourier transform infrared spectroscopy (FTIR) and 1H nuclear magnetic resonance (1H NMR) spectra were used to study the structures of obtained polymers. Transmission electron microscope (TEM) and Dynamic laser scattering (DLS) were employed to monitor the morphology and size distribution of mPEG-b-PCL-DOX nanoparticles (NPs). The mPEG-b-PCL-DOX NPs were administrated to KM rats by intraperitoneal injection to study the bio-safety of final NPs. The cell uptake and in?vitro anti-tumor activity of final NPs were carried out with HCT116 cells as models. FTIR and 1H NMR spectra confirmed the obtaining of mPEG-b-PCL-DOX. The fabricated NPs were in round shapes with an average diameter of 300?nm. These NPs did not induce hemolysis and physiological or pathological changes in rats’s organs. Finally, cell teats showed that these NPs could be endocytosed by HCT 116 cells, and they had better anti-tumor effects than free DOX did. Therefore, the mPEG-b-PCL-DOX NPs had a potential application in anti-cancer therapy.
Aras CansuTümay ?zer ElifG?ktalay G?khanSaat Gülbahar...
18页
查看更多>>摘要：Abstract Electrospun nanofibers have a natural wound healing effect due to their similarity to the extracellular matrix (ECM). Nigella sativa oil, which has therapeutic properties, is used for a wide variety of applications in traditional medicine. The aim of this study was to investigate the release characteristic and wound healing performance of Nigella sativa oil (NSO) loaded polyurethane (PU) electrospun nanofibrous mats in wound dressing applications. In addition, the antibacterial activity and cytotoxicity of the electrospun mats were studied. Analyses using a scanning electron microscope (SEM) showed that PU/NSO nanofibrous mat with an average fiber diameter of 416?±?66?nm were successfully fabricated. NSO was released at a maximum ratio of 30% from the electrospun mat, and the Korsmeyer-Peppas model was identified as best for determining the release mechanism. Significant antibacterial activity was observed against Staphylococcus aureus (90.26%) and Escherichia coli (95.75%). The developed PU/NSO nanofibrous mat increased the cell viability more than 100% in human umbilical vein endothelial cell line (HUVEC) cell line. The NSO loaded PU nanofibrous mat significantly promoted the wound healing process on a rat wound model, and its wound closure reached approximately 85% compared to the control groups on the 9th day (p?<?0.01). The results indicated PU/NSO nanofibrous mat is a suitable candidate for a wound dressing.
查看更多>>摘要：Abstract Recently, different carbon-based nanomaterials have been used as reinforcing agents in acrylic bone cement formulations. Among them, graphene oxide (GO) has attracted the attention of scientific community since it could improve not only the mechanical properties but also the biocompatibility characteristics of these materials. However, using GO presents some drawbacks, such as its poor dispersion and lack of interaction with polymeric matrices, which should be prior resolved to achieve its optimal performance in acrylic bone cement. Thus, in this work, GO was treated with 3-methacryloxy propyl trimethoxy silane at various concentrations (1, 3 and 5?wt.%) to improve the interaction between the nanofiller and the poly (methyl methacrylate) matrix. Modified GO was incorporated at different percentages (0.1, 0.5 and 0.75?wt.%) into acrylic bone cement formulations and some properties were evaluated. The silanization process of the GO was confirmed by FTIR, TGA and EDX. The improvement in the mechanical performance was monitored on the compression properties whereas those related with biological properties were evaluated by osteoblast cell viability and hemocompatibility tests. Results suggest that using a 1?wt.% of the silane coupling agent, during surface treatment of GO, yields the best mechanical performance in this type of materials. It was also found that the presence of neat GO or silanized GO does not compromise the cytocompatibility and hemocompatibility of acrylic bone cement formulations.
查看更多>>摘要：Abstract It is well known that poly(2-methoxyethyl acrylate) (PMEA) has good blood compatibility and its performance is attributed to its water structure. Recently, we applied solution nuclear magnetic resonance spectroscopy (solution-NMR) for analyzing the water structure in PMEA at ambient temperature and concluded that this method is useful because of the clear observation of the resonance peaks at low and high magnetic field (downfield and upfield, respectively) areas indicating the existence of more than two types of water. The present study was performed to compare the water structure of poly(tetrahydrofurfuryl acrylate) (PTHFA) and poly(2-hydroxyethyl methacrylate) (PHEMA) using solution 2H-NMR and deuterium oxide as water at the temperature range 15–45?°C. It was found that PTHFA has a different water structure from that of PHEMA. Water in PTHFA clearly showed two resonance peaks at downfield and upfield areas, with different spin-lattice relaxation times, T1 2H (high and low values, respectively). These observations are similar to those of PMEA. In contrast, PHEMA showed only one broad resonance peak (at downfield) with a low T1 2H value. Based on these observations, this study discusses the effect of water structures on the blood compatibility of these polymers.
查看更多>>摘要：Abstract The protein/cell interactions with the surface at the blood-biomaterial interface generally control the efficiency of biomedical devices. A wide range of active processes and slow kinetics occur simultaneously with many biomaterials in healthcare applications, leading to multiple biological reactions and reduced clinical functions. In this work, we present a brief review of studies as the interface between proteins and biomaterials. These include mechanisms of resistance to proteins, protein-rejecting polyelectrolyte multilayers, and coatings of hydrophilic, polysaccharide and phospholipid nature. The mechanisms required to attain surfaces that resist adhesion include steric exclusion, water-related effects, and volume effects. Also, approaches in the use of hydrophilic, highly hydrated, and electrically neutral coatings have demonstrated a good ability to decrease cell adhesion. Moreover, amongst the available methods, the approach of layer-by-layer deposition has been known as an interesting process to manipulate protein and cell adhesion behavior.
查看更多>>摘要：Abstract Due to the insufficient endothelialization and the poor colonization of smooth muscle cells (SMCs), small-diameter vascular tissue engineering is still challenging. An ideal vascular graft is expected to effectively support the formation of endothelial monolayer and the colonization of SMCs. In this study, we proposed a bilayered scaffold with hierarchical pore size constructed from nano and microfibers by electrospinning PCL-PEG-PCL (PCE) and a blend of PCE and gelatin (PCEG) sequentially. The structural features of nano and microfibers were tuned by the concentration of PCE and the proportion of PCE/gelatin in electrospun solution respectively. The results demonstrated the best nanofiber morphology and relatively high mechanical properties were achieved in 18% PCE (w/v) (PCE18) and PCE and gelatin with a weight ratio of 7:3 (P7G3) at a concentration of 18% (w/v) electrospun membranes. The in vitro co-culturing studies of cells and membranes indicated all the PCE membranes supported the proliferation and spreading of endothelial cells and the further endothelialization of the membranous surface, while PCEG membranes facilitated the migration inward of SMCs. Taking the porosity and mechanical properties into consideration, PCE18 and P7G3 were chosen to construct the inner and outer layers of the bilayered scaffold with hierarchical pore size respectively. The circumferential ring test demonstrated that the bilayered scaffold has good mechanical property both in dry and wet state. After cells were co-cultured with this bilayered scaffold for 7?days, the results manifested a continuous endothelial monolayer has formed on the luminal surface and the SMCs have started to colonized from outer layers, indicating the vast potential of this bilayered scaffold in vascular remodeling and regeneration.
查看更多>>摘要：Abstract In the first step of this study, 2-oxo-2-[(2,4,6-trifluorophenyl)amino]ethyl-2-methylprop-2-enoate(OTFAMA) monomer was synthesized and characterized. Then, a series copolymers were obtained by free-radical copolymerization method of OTFAMA and glycidyl methacrylate (GMA), which is a commercial monomer at 65?°C in 1,4-dioxane solvent. Structural characterizations of synthesized monomer and copolymers were carried out using FTIR, 1H-13C-NMR instruments. The composition of the copolymers was estimated by elemental analysis. The reactivity ratios (r 1 and r 2) were obtained from the various linear graphical methods. The values of r 1 (OTFAMA) = 0.33 and r 2 (GMA) = 0.45 were found from the same graphical methods. The thermal behaviors of all the polymers have been investigated using the differential scanning calorimetry (DSC) and the thermogravimetric analysis (TGA). A kinetic study of the thermal decompostion of copolymers was investigated using thermogravimetric analyzer with non-isothermal methods selected for analyzing solid-state kinetics data. The average activation energy values were calculated via Kissinger and Ozawa models in a period of α?=?0.10–0.80. Photo stability of the copolymers was investigated. Also, the biological activity of the copolymers against different bacterial and fungal species has been investigated.
查看更多>>摘要：Abstract In biomaterials and drug delivery, the development of polymeric therapies capable of the synchronized release of several therapeutic agents remains an important challenge. In this article, we describe the development of polymeric nanoparticles (PNPs) with precise molar ratios of Curcumin (CUR) and Methotrexate (MEX). The highly symmetric synthetic approach allows for the development of novel NPs-based combination therapeutic strategies for colorectal cancer. The fabricated CUR/MEX@PNPs were confirmed by transmission microscopy (TEM) and the size and polydispersity index were assessed through the dynamic light scattering (DLS). CUR and MEX were released slowly from the drug delivery without any burst impact. Furthermore, CUR/MEX@PNPs exhibited dose-responsive cytotoxic effects in CL40 and SW1417 cells, with a greater cell death ratio than that of free drugs. The drugs-loaded polymeric nanomaterials were more easily taken up by cancer cells in?vitro, according to the cellular uptake analysis. The apoptotic features were confirmed by various fluorescence staining assay. The results of the fluorescent assay reveal that the nanomaterials remarkably induce apoptosis in colorectal cancer cells. Further, the apoptosis cell death mechanism was displayed that these nanomaterials significantly induce apoptosis in the targeted cancer cells. Overall, the current investigation confirmed that CUR/MEX@PNPs could be used to successfully combat colorectal cancers in the immediate future. Highlights We have developed the Curcumin (CUR) and Methotrexate (MEX) encapsulated polymeric nanoparticles (CUR/MEX@PNPs).CUR/MEX@PNPs confirmed by the various analytical methods.CUR/MEX@PNPs enhanced the in?vitro proliferation against the colorectal cancer cells.Biochemical analysis results reveals that CUR/MEX@PNPs induce apoptosis.The apoptosis was confirmed by Annexin-V-FITC and PI for flow cytometry.
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