Herein, we aim to develop a facile method for the fabrication of mechanical metamaterials from templated polymerization of thermosets including phenolic and epoxy resins using self-assembled block ...copolymer, polystyrene–polydimethylsiloxane with tripod network (gyroid), and tetrapod network (diamond) structures, as templates. Nanoindentation studies on the nanonetwork thermosets fabricated reveal enhanced energy dissipation from intrinsic brittle thermosets due to the deliberate structuring; the calculated energy dissipation for gyroid phenolic resins is 0.23 nJ whereas the one with diamond structure gives a value of 0.33 nJ. Consistently, the gyroid-structured epoxy gives a high energy dissipation value of 0.57 nJ, and the one with diamond structure could reach 0.78 nJ. These enhanced properties are attributed to the isotropic periodicity of the nanonetwork texture with plastic deformation, and the higher number of struts in the tetrapod diamond network in contrast to tripod gyroid, as confirmed by the finite element analysis.
Herein, we aim to develop a simple method for the fabrication of well-ordered nanoporous materials from polystyrene-block-poly(dimethylsiloxane) (PS-PDMS) diblock copolymer. By taking advantage of ...the intrinsic strong segregation strength between PS and PDMS, gyroid-structured PS-PDMS can be simply acquired from initially lamellae-forming PS-PDMS (i.e., PS-PDMS with almost equal volume fractions for the two blocks) by using solution casting with PS selective solvent. With the high etching selectivity of the constituted blocks, nanoporous PS materials with gyroid-structured nanochannels can be obtained from self-assembled PS-PDMS by selectively etching the PDMS block using hydrofluoric acid. The fabricated nanoporous PS can be used as a template for controlled synthesis followed by removal of the PS to obtain various types of nanoporous materials including organics (such as epoxy) and inorganics (such as SiO2 and Ni) with well-defined gyroid textures.
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•A simple method for acquiring gyroid-structured PS-PDMS from lamellar composition is proposed.•Well-order nanoporous PS can be obtained from solution-cast PS-PDMS by selective etching using hydrofluoric acid.•Gyroid-structured organics and inorganics can be fabricated by using nanoporous PS for templated synthesis.
Abstract
Bioinspired from structural coloration of butterfly wing structure, this work aims to fabricate nanoporous chitosan for UVC reflection. By taking advantage of self-assembled polystyrene-
b
...-polydimethylsiloxane (PS-
b
-PDMS) with double gyroid texture followed by hydrofluoric acid etching of PDMS block, nanoporous PS with well-defined nanochannels can be fabricated, and used as a template for templated crosslinking reaction of chitosan through a multiple pore-filling process. Well-ordered nanoporous chitosan with shifting networks in nanoscale can be successfully fabricated after removal of the PS template. With the low absorption of chitosan in the ultraviolet region and the shifting networks for opening the bandgap, it is appealing to exploit the nanonetwork chitosan as high reflective materials for UVC optical devices, as evidenced by finite-difference time-domain (FDTD) simulation and optical measurements experimentally.
Nanoporous epoxy with gyroid texture is fabricated by using a nanoporous polymer with gyroid-forming nanochannels as a template for polymerization of epoxy. The nanoporous polymer template is ...obtained from the self-assembly of degradable block copolymer, polystyrene-b-poly(l-lactide) (PS–PLLA), followed by hydrolysis of PLLA blocks. Templated polymerization can be conducted under ambient conditions to create well-defined, bicontinuous epoxy networks in a PS matrix. By taking advantage of multistep curing of epoxy, well-ordered robust nanoporous epoxy can be obtained after removal of PS template, giving robust porous materials. The through-hole nanoporous epoxy in the film state can be used as a coated layer to enhance the adsorbability for both lysozyme and bovine serum albumin.
Photothermal-responsive (PTR) and anti-oxidative silk fibroin/dopamine nanoparticles (SD NPs) mediated by tyrosinase were produced, and decorated either by curcumin or albumin (BSA) to produce ...SD/curcumin or SD/BSA NPs as drug delivery vehicles, respectively. Both drug loaded NPs were further blended into SF solutions to produce SD films, as a depot-based drug delivery. The reaction mechanisms for producing new SD NPs were proposed. Anti-oxidative activities for SD NPs were examined by H2O2 scavenge capacities of NPs. NPs were not cytotoxic at concentration of 1000μg/mL. Moreover, heparin was coated to SD films to produce SDH films for temporary implants. Cumulative release profiles for drugs loaded SDH films showed fast releases and then sustained releases stages. Furthermore, the releases of curcumin in sustained stages for varying SD/curcumin NPs loaded into SDH films were dependent on amounts of NPs. BSA releases profiles for SD/BSA NPs loaded into SDH films were similar to those profiles for the films carried with SD/curcumin NPs but release periods of BSA were short. Degrees of PTR effects with irradiation of near infrared on the releases of two drugs loaded films were different. Blood clot at wound areas of rats with SDH films implantations was not found for 24 h study.
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Pacemaker cells can be differentiated from stem cells or transdifferentiated from quiescent mature cardiac cells via genetic manipulation. Here we show that the exposure of rat quiescent ventricular ...cardiomyocytes to a silk-fibroin hydrogel activates the direct conversion of the quiescent cardiomyocytes to pacemaker cardiomyocytes by inducing the ectopic expression of the vascular endothelial cell-adhesion glycoprotein cadherin. The silk-fibroin-induced pacemaker cells exhibited functional and morphological features of genuine sinoatrial-node cardiomyocytes in vitro, and pacemaker cells generated via the injection of silk fibroin in the left ventricles of rats functioned as a surrogate in situ sinoatrial node. Biomaterials with suitable surface structure, mechanics and biochemistry could facilitate the scalable production of biological pacemakers for human use.
Alzheimer's disease (AD) is the most common cause of dementia of late life. To enhance our understanding of AD proteome, the serum proteins were analyzed using two-dimensional gel electrophoresis ...(2DE) combined with nano-high performance liquid chromatography electrospray ionization tandem mass spectrometry (nano-HPLC-ESI-MS/MS) followed by peptide fragmentation patterning. In this study, six protein spots with differential expression were identified. Five up-regulated proteins were identified as actin, apolipoprotein A-IV (Apo A-IV), inter-alpha-trypsin inhibitor heavy chain H4 (ITIH4), alpha-1-antitrypsin (AAT), and antithrombin-III (AT-III); one protein, activity-dependent neuroprotector homeobox protein (ADNP) was down-regulated in AD patients. These proteins with differential expression in the serum may serve as potential indicators of AD. Our results suggested that ADNP may play an important role in slowing the progression of clinical symptoms of AD.
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► We used proteomic approaches in an attempt to identify the serum biomarkers for AD. ► Six proteins with differential expression were identified in AD serum samples. ► ADNP may play an important role in slowing the progression of AD clinical symptoms. ► The identified proteins are valuable for screening biomarkers for further AD study.
Abstract Polysaccharides and proteins profoundly impact the development and growth of tissues in the natural extra-cellular matrix (ECM). To mimic a natural ECM, polysaccharides were incorporated ...to/or co-sprayed with silk fibroin (SF) to produce SF/chitosan (CS) or SF/CS–hyaluronic acid (SF/CS–HA) microparticles that were further processed by mechanical pressing and genipin cross-linking to produce hybrid cardiac patches. The ATR–FTIR spectra confirm the co-existence of CS or CS–HA and SF in microparticles and patches. For evaluating the cellular responses of rMSCs to the SF/CS and SF/CS–HA cardiac patches, the growth of rMSCs and cardiomyogenic differentiation of 5-aza inducing rMSCs cultured on patches was examined. First, the isolated rMSCs were identified with various positive and negative surface markers such as CD 44 and CD 31 by a flow cytometric technique, respectively. For examining the growth of rMSCs on the patches, MTT viability assay was performed, and the results demonstrated that the growth of rMSCs on SF and SF-hybrid patches significantly exceeded ( P < 0.001) that on culture wells after seven days of cultivation. Additionally, the relative growth rates of rMSCs on SF/CS and SF/CS–HA hybrid patches were significantly better ( P < 0.01) than that on SF patches that were also observed by using vimentin stain to the cells. For instance, the relative cell growth rates (%) in cell culture wells, SF, SF/CS and SF/CS–HA patches were 100%, 282.9 ± 6.5%, 337.0 ± 8.0% and 332.6 ± 6.6% ( n = 6, for all), respectively. For investigating the effects of the hybrid patches on cardiomyogenic differentiation of 5-aza inducing rMSCs, the expressions of specific cardiac genes of cells such as Gata4 and Nkx2.5 were examined by real-time quantitative polymerase chain reaction (real-time PCR) analysis. The results of cardiomyogenic differentiation of induced rMSCs on SF/CS and SF/CS–HA hybrid patches significantly improved the expressions of cardiac genes of Gata4, Nkx2.5, Tnnt2 and Actc1 genes (all, P < 0.01 or better, n = 3) than those on SF patches and culture wells. Interestingly, the results of cardiac gene expressions of the cells on the SF/CS–HA hybrid patches were the most pronounced in promoting cardiomyogenic differentiations in this investigation. Furthermore, immunofluorescence staining of cardiac proteins such as cardiotin and connexin 43 for induced rMSCs cultured on SF/CS and SF/CS–HA hybrid patches were much pronounced compared with SF patches, indicating the improvements of cardiomyogenic differentiation on the hybrid patches. The results of this study demonstrate that the SF/CS and SF/CS–HA hybrid patches may be promising biomaterials for regenerating infarcted cardiac tissues.
The purpose of this study was to investigate the IOP-lowering effects of the ITRI-E-212, a new Rho-associated protein kinase (ROCK) inhibitor. ITRI-E-212 improved fluid outflow through the trabecular ...meshwork and reduced IOP with transient and mild conjunctival hyperemia. ITRI-E-212 can potentially be developed into new antiglaucoma agents.
ITRI-E-212 was selected from more than 200 amino-isoquinoline structures because of its adequate solubility and drug-loading percentage in eye drops. ITRI-E-212 has less than 50% inhibitory concentration (IC50) against ROCK2. The in vitro kinase inhibition was evaluated using the ADP-Glo kinase assay. A comprehensive analysis of the kinase inhibitor selectivity of ITRI-E-212 was performed using the KINOMEscan methodology. The IOP-lowering effect and tolerability of ITRI-E-212 were investigated in normotensive and ocular hypertensive rabbits. The pharmacokinetics study was performed in vivo in the aqueous humor (AH), and hyperemia was assessed.
ITRI-E-212 showed high in vitro inhibitory activity against ROCK2 and high specificity against AGC kinases. The mean IOP-lowering effect of ITRI-E-212 in normotensive and ocular hypertensive models was 24.9% and 28.6%, respectively; 1% ITRI-E-212 produced notable reductions in IOP that were sustained for at least 6 hours after each dose once per day. Only transient, mild hyperemia was observed. The compound extracted from the AH reached 78.4% ROCK2 kinase inhibition at 1 hour after dose administration and was sustained for 4 hours.
ITRI-E-212 is a novel and highly specific ROCK2 inhibitor with the ability to lower IOP in animal models. It has favorable pharmacokinetic and ocular tolerability profiles with only minimal conjunctival hyperemia.
The feasibility of silk fibroin protein (SF) scaffolds for tissue engineering applications to promote cell proliferation has been demonstrated, as well as the ability to mimic natural extra-cellular ...matrix (ECM), SF/chitosan (CS), a polysaccharide, scaffolds for tissue engineering. However, the response of cells to SF/CS–hyaluronic acid (SF/CS–HA) scaffolds has not been examined, which this study attempts to do and then compares those results with those of SF scaffolds. SF/CS–HA microparticles were fabricated to produce scaffolds in order to examine the proliferations of human dermal fibroblasts (HDF) in the scaffolds. Positive zeta potentials and ATR-FTIR spectra confirmed the co-existence of SF and CS–HA in SF/CS–HA microparticles. HDF proliferated well and migrated into SF/CS–HA scaffolds for around 160 μm in depth, as well as those in SF scaffolds after 7 days of cultivation, as observed using confocal microscopy. Interestingly, HDF grown in SF/CS–HA scaffolds had a markedly higher cell density than that in SF ones. Additionally, MTT assay revealed that the growth rates of HDF in SF/CS–HA scaffolds significantly exceeded (
P
< 0.01,
n
= 5) those in scaffolds of SF and SF/CS. The daily glucose consumptions and lactate formations, metabolic parameters, of HDF grown in SF/CS–HA and SF/CS scaffolds were significantly higher (
P
< 0.01,
n
= 3) than those in SF ones in most culturing days. Results of this study suggest that SF/CS–HA scaffolds have better cell responses for tissue engineering applications than SF ones.
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