Read by QxMD icon Read


Alexander E G Baker, Roger Y Tam, Molly S Shoichet
In order to mimic native breast cancer cell growth in vitro as spheroids, a well-defined matrix that mimics the tumor microenvironment is required. Finding a biomimetic material for 3D cell culture, other than Matrigel, has challenged the field. Since hyaluronan is naturally abundant in the tumor microenvironment and can be chemically modified, we synthesized a hyalu-ronan hydrogel with independently tunable mechanical and chemical properties for 3D culture of breast cancer cells. By modifying HA with distinct bioorthogonal functional groups, its mechanical properties are controlled by chemical crosslinking via oxime liga-tion while its biochemical properties are controlled by grafting bioactive peptides via Diels-Alder chemistry...
October 17, 2017: Biomacromolecules
Kazuki Fukushima, Yuto Inoue, Yuta Haga, Takayuki Ota, Kota Honda, Chikako Sato, Masaru Tanaka
We developed a biodegradable polycarbonate that demonstrates antithrombogenicity and vascular cell adhesion via organocatalytic ring-opening polymerization of a trimethylene carbonate (TMC) analogue bearing a methoxy group. The monoether-tagged polycarbonate demonstrates a platelet adhesion property that is 93 and 89% lower than those of poly(ethylene terephthalate) and polyTMC, respectively. In contrast, vascular cell adhesion properties of the polycarbonate are comparable to those controls, indicating a potential for selective cell adhesion properties...
October 17, 2017: Biomacromolecules
Arthur Markus Anton, Aniela Heidebrecht, Nasir Mahmood, Mario Beiner, Thomas Scheibel, Friedrich Kremer
Spider dragline silk is distinguished through the highest toughness of all natural as well as artificial fiber materials. To unravel the toughness's molecular foundation and to enable manufacturing biomimetic analogues, we investigated the morphological and functional structure of recombinant fibers, which exhibit toughness similar to that of the natural template, on the molecular scale by means of vibrational spectroscopy and on the mesoscale by X-ray scattering. Whereas the former was used to identify protein secondary structures and their alignment in the natural as well as artificial silks, the latter revealed nanometer-sized crystallites on the higher structural level...
October 17, 2017: Biomacromolecules
Jia Tian, Lei Xu, Yudong Xue, Xiaoze Jiang, Weian Zhang
Drug resistance is a primary obstacle that seriously reduces therapy efficiency of most chemotherapeutic agents. To address this issue, the photochemical internalization (PCI) was employed to help the anticancer drug escape from lysosome and improve their translocation to the nucleus. Herein, a pH-sensitive porphyrin-based amphiphilic block copolymer (PEG113-b-PCL54-a-porphyrin) was synthesized, which was acted not only as a carrier for the delivery of DOX, but also as a photosensitizer for PCI.PEG113-b-PCL54-a-porphyrin as a drug carrier exhibited a higher drug loading capacity, entrapment efficiency and DOX release content...
October 16, 2017: Biomacromolecules
Emily H Pilkington, May Lai, Xinwei Ge, William J Stanley, Bo Wang, Miaoyi Wang, Aleksandr Kakinen, Marc-Antoine Sani, Michael R Whittaker, Esteban N Gurzov, Feng Ding, John F Quinn, Thomas P Davis, Pu Chun Ke
Protein aggregation into amyloid fibrils is a ubiquitous phenomenon across the spectrum of neurodegenerative disorders and type 2 diabetes. A common strategy against amyloidogenesis is to minimize the populations of toxic oligomers and protofibrils by inhibiting protein aggregation with small molecules or nanoparticles. However, melanin synthesis in nature is realized by accelerated protein fibrillation to circumvent accumulation of toxic intermediates. Accordingly, we designed and demonstrated the use of star-shaped poly(2-hydroxyethyl acrylate) (PHEA) nanostructures for promoting the aggregation while ameliorating the toxicity of human islet amyloid polypeptide (IAPP), the peptide involved in glycemic control and the pathology of type 2 diabetes...
October 16, 2017: Biomacromolecules
Jiabing Ran, Hao Zeng, Janak Lal Pathak, Pei Jiang, Yi Bai, Pan Yan, Guanglin Sun, Xinyu Shen, Hua Tong, Bin Shi
In bone tissue engineering (BTE), most of the currently developed scaffolds still lack the ability to demonstrate high porosity and high mechanical strength simultaneously or the ability to maintain bioactivity and sustained release of loaded biofactors. In this work, we constructed an anisotropic triple-pass tubular framework within a lyophilized porous GEL scaffold using FP, which was prepared by coating DEX-covered Whatman paper (WP) using the silk fibroin (SF) membrane with β-sheet conformation. This novel structural design endowed the functionalized paper frame (FPF)/scaffold implant high porosity, high mechanical strength, and sustained DEX delivery capability...
October 16, 2017: Biomacromolecules
Laura G Bracaglia, Michael Messina, Shira Winston, Che-Ying Kuo, Max Lerman, John P Fisher
Vascular grafts that can support total replacement and maintenance by the body of the injured vessel would improve outcomes of major surgical reconstructions. Building scaffolds using components of the native vessel can encourage biological recognition by native cells as well as mimic mechanical characteristics of the native vessel. Evidence is emerging that incorporating predetermined building-blocks into a tissue engineering scaffold may oversimplify the environment and ignore critical structures and binding sites essential to development at the implant...
October 16, 2017: Biomacromolecules
Wenjing Lin, Xiaofang Zhang, Long Qian, Na Yao, Ya Pan, Lijuan Zhang
Current researches are mainly trend to address the development of multi-functional nanocarriers which could precisely reach the disease sites, release drugs in a controlled-manner and act as an imaging agent for both diagnosis and targeted therapy. In this study, a pH-sensitive theranostic nanoplatform as a promising dual-functional nanovector for tumor therapy and CT imaging was developed. 21-arm star like triblock polymerof β-cyclodextrin-{poly(-caprolactone)-poly(2-aminoethyl methacrylate)-poly[poly(ethylene glycol) methyl ether methacrylate]}21 [β-CD-(PCL-PAEMA-PPEGMA)21] with stable unimolecular micelles formed in aqueous solution was firstly synthesized by combined ROP with ARGET ATRP techniques, and then were used as template for fabrication of gold nanoparticles (AuNPs) with uniform sizes and excellent colloidal stability in situ, followed by the encapsulation of doxorubicin (DOX) with maximum entrapment efficiency up to 60% to generate the final product β-CD-(PCL-PAEMA-PPEGMA)21/AuNPs/DOX...
October 15, 2017: Biomacromolecules
Eunkyoung Kim, Mijeong Kang, Tanya Tschirhart, Mackenzie Malo, Ekaterina Dadachova, Gaojuan Cao, Jun-Jie Yin, William E Bentley, Zheng Wang, Gregory F Payne
Melanins are ubiquitous in nature but their biological activities and functions have been difficult to discern. Conventional approaches to determine material function start by resolving structure and then characterize relevant properties. These approaches have been less successful for melanins because of their complex structure and insolubility, and because their relevant properties are not readily characterized by conventional methods. Here, we report a novel spectroelectrochemical reverse engineering approach that focuses on redox and radical scavenging activities...
October 15, 2017: Biomacromolecules
Pascal Bertsch, Stéphane Isabettini, Peter Fischer
Nanocrystalline cellulose (NCC) is a promising material for formation of hydrogels and nematically ordered phases. While salt addition is known to facilitate hydrogel formation, it remains unclear whether this originates from cationic bridging or charge screening effects. Herein, we demonstrate the effect of mono- and divalent salts on NCC gelation and nematic ordering. A strong correlation of NCC suspension zeta-potential and rheological behavior was found. Lower concentrations of divalent cations were needed to decrease NCC zeta-potential and form hydrogels...
October 13, 2017: Biomacromolecules
Chuncai Zhou, Yue Yuan, Panyu Zhou, Fangyingkai Wang, Yuanxiu Hong, Nuosha Wang, Shuogui Xu, Jianzhong Du
It is an important challenge for bone repair to effectively deliver growth factors and at the same time to prevent and cure inflammation without obvious pathogen resistance. Herein, we designed a kind of antibacterial peptide-mimetic alternating copolymers (PMACs) to effectively inhibit and kill both Gram-positive and Gram-negative bacteria. The minimum inhibition concentrations (MICs) of the PMACs against E. coli and S. aureus are 8.0 μg/mL, which are much lower than that of antibacterial peptides synthesized by other methods such as widely used ring-opening polymerization of N-carboxyanhydride (NCA)...
October 11, 2017: Biomacromolecules
Mahentha Krishnamoorthy, Danyang Li, Amir S Sharili, Tina Gulin-Sarfraz, Jessica M Rosenholm, Julien Ezra Gautrot
Polymer brush-functionalised nanomaterials offer interesting features for the design of gene delivery vectors as their physico-chemical and structural properties can be designed independently of the chemistry, size and shape of the nanomaterial core. However, little is known of the parameters regulating the adsorption and infiltration of DNA molecules at the surface of positively charged polymer brushes, despite the importance of such processes for gene delivery. Here we investigate the role of the molecular environment (e...
October 11, 2017: Biomacromolecules
Cristina Cepraga, Sophie Marotte, Edna Ben Daoud, Arnaud Favier, Pierre-Henri Lanoe, Cyrille Monnereau, Patrice Baldeck, Chantal Andraud, Jacqueline Marvel, Marie-Therese Charreyre, Yann Leverrier
One of the challenges of photodynamic therapy is to increase the penetration depth of light irradiation in the tumor tissues. Although two-photon excitation strategies have been developed, the two-photon absorption cross-sections of clinically used photosensitizers are generally low (below 300 GM). Besides, photosensitizers with high cross-section values are often non water-soluble. In this research work, a whole family of photosensitizer-polymer conjugates was synthesized via the covalent binding of a photosensitizer with a relatively high cross-section along a biocompatible copolymer chain...
October 11, 2017: Biomacromolecules
Jiayi Yu, Yanyi Xu, Shan Li, Gabrielle V Seifert, Matthew L Becker
Hydroxyapatite (HA) nanocrystals were blended with 1,6-hexanediol L-phenylalanine-based poly(ester urea) (PEU). These composites were 3D-printed into porous scaffolds (75% porosity) via fused deposition modeling (FDM) technique and seeded with MC3T3-E1 pre-osteoblast cells in vitro to examine their bioactivity. The resulting 3D-printed scaffolds exhibited a compressive modulus of ~50 MPa after 1-week incubation in PBS at 37 °C, a cell viability of >95%, and a composition dependent enhancement of radio-contrast...
October 11, 2017: Biomacromolecules
Qing Li, Fei Lu, Guofang Zhou, Kun Yu, Bitao Lu, Yang Xiao, Fangying Dai, Dayang Wu, Guangqian Lan
Silver inlaid with gold nanoparticles (Au-Ag NPs) prepared by using egg white with an average sized of 10 nm and homogeneous dispersion were tested and presented red fluorescence. Au-Ag NPs were loaded into chitosan as wound dressing (CS-Au-Ag). CS-Au-Ag released silver ions faster, in higher amount, and in a more durable manner than chitosan dressing loaded with silver nanoparticles with the same silver content (CS-Ag), consequently, showing enhanced antibacterial activity. Cytotoxicity tests indicated that CS-Au-Ag showed low cytotoxicity to L929 cells similar to CS-Ag...
October 11, 2017: Biomacromolecules
Dominic W Malcolm, Margaret A T Freeberg, Yuchen Wang, Kenneth R Sims, Hani A Awad, Danielle S W Benoit
pH-responsive diblock copolymers provide tailorable nanoparticle (NP) architecture and chemistry critical for siRNA delivery. Here, diblock polymers varying in first (corona) and second (core) block molecular weight (Mn), corona/core ratio, and core hydrophobicity (%BMA) were synthesized to determine their effect on siRNA delivery in murine tenocytes (mTenocyte) and murine and human mesenchymal stem cells (mMSC and hMSCs, respectively). NP-mediated siRNA uptake, gene silencing, and cytocompatibility were quantified...
October 11, 2017: Biomacromolecules
Long Gao, Zhongyue Huang, Shifeng Yan, Kunxi Zhang, Shenghua Xu, Guifei Li, Lei Cui, Jingbo Yin
The microcarrier system offers an attractive method for cellular amplification and phenotype enhancement in the field of bone tissue engineering. However, it remains a challenge to fabricate porous microcarriers with osteoinductive activity for speedy and high-quality osseointegration in regeneration of serious complication of bone fracture, like nonunion. Here, we present a facile method for the first time manufacture microcarriers with osteogenic effects and properties based on well controlled and long-term Sr(2+) release...
October 10, 2017: Biomacromolecules
Kunkun Zhu, Jiangjiang Duan, Jinhua Guo, Shuangquan Wu, Ang Lu, Lina Zhang
Chitosan has biocompatibility and biodegradability, however the practical use of the bulk chitosan materials is hampered by its poor strength, which can not satisfy the mechanical property requirement of organs. Thus, the construction of highly strong chitosan-based materials has attracted much attention. Herein, the high strength nanofibrous hydrogels and films (CS-E) were fabricated from the chitosan solution in LiOH/KOH/urea aqueous system via a mild regenerating process. Under the mild condition (ethanol at low temperature) without the severe fluctuation in the system, the alkaline-urea shell around the chitosan chains was destroyed, and the naked chitosan molecules had sufficient time for the orderly arrangement in parallel manner to form relatively perfect nanofibers...
October 9, 2017: Biomacromolecules
Zhiyuan Ma, Yong-Guang Jia, X X Zhu
Betulin is a natural triterpene compound with anti-carcinogen and antiviral activities. It is conjugated with methacrylate and then copolymerized with a galactose-bearing comonommer by RAFT polymerization to yield both random and block copolymers. These glycopolymers are designed to possess similar molecular weights and monomer compositions for easy comparison. They self-assembled into micelles as shown by dynamic light scattering (DLS) and transmission electron microscopy. The smaller micelles formed by the random copolymers facilitated the encapsulation of Nile Red and released more of this hydrophobic model compound (46% in 4 days versus 32% released from the block copolymers)...
October 5, 2017: Biomacromolecules
Ryunosuke Funahashi, Yusuke Okita, Hiromasa Hondo, Mengchen Zhao, Tsuguyuki Saito, Akira Isogai
Layer-by-layer peeling of surface molecules of native cellulose microfibrils was performed using a repeated sequential process of 2,2,6,6-tetramethylpiperidine-1-oxyl radical-mediated oxidation followed by hot alkali extraction. Both highly crystalline algal and tunicate celluloses and low-crystalline cotton and wood celluloses were investigated. Initially, the C6-hydroxy groups of the outermost surface molecules of each algal cellulose microfibril facing the exterior had the gauche-gauche (gg) conformation, whereas those facing the interior had the gauche-trans (gt) conformation...
October 5, 2017: Biomacromolecules
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"