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alginate hydrogel

In-Yong Kim, Hyungsoo Choi, Kyekyoon Kevin Kim
In this study, we investigated the effect of intracapsular environment on the survival of anchorage-dependent cells (ADCs) encapsulated in alginate microcapsules with three different core structures, i.e., liquid, semi-liquid and microsphere-encapsulating semi-liquid core, using NIH 3T3 fibroblasts as an ADC model. For the latter, we fabricated poly (ε-caprolactone) microspheres and co-encapsulated them with the cells, to establish cell-substrate interactions in the capsule. The fibroblast cells co-encapsulated with the microspheres exhibited higher survival and growth than those without...
January 18, 2017: Journal of Microencapsulation
Bao-Ngoc B Nguyen, Rebecca A Moriarty, Tim Kamalitdinov, Julie M Etheridge, John P Fisher
The generation of functional, vascularized tissues is a key challenge for the field of tissue engineering. Before clinical implantations of such tissue engineered bone constructs can succeed, tactics to promote neovascularization need to be strengthened. We have previously demonstrated that the tubular perfusion system (TPS) bioreactor is an effective culturing method to augment osteogenic differentiation and maintain viability of human mesenchymal stem cells (hMSC). Here, we devised a strategy to address the need for a functional microvasculature by designing an in vitro coculture system that simultaneously cultures osteogenic differentiating hMSCs with endothelial cells (ECs)...
January 17, 2017: Journal of Biomedical Materials Research. Part A
Jingjing Hu, Yanchun Quan, Yuping Lai, Zhao Zheng, Zhiqi Hu, Xinyu Wang, Tianjiao Dai, Qiang Zhang, Yiyun Cheng
Aminoglycosides are a family of critically important antibiotics for the treatment of serious infections including multidrug-resistant pathogens. However, clinical use of aminoglycoside antibiotics is compromised by bacterial biofilm formation at subinhibitory concentrations or adverse side effects such as ototoxicity and nephrotoxicity at high antibiotic doses. Preparation of aminoglycoside formulation that allows on-demand drug delivery is a solution to this sticky issue. Here, we designed a new type of aminoglycoside hydrogels by cross-linking oxidized polysaccharides such as dextran, carboxymethyl cellulose, alginate, and chondroitin using aminoglycosides as cross-linkers...
January 7, 2017: Journal of Controlled Release: Official Journal of the Controlled Release Society
Jae Won Lee, Kuen Yong Lee
Controlling the cell-matrix interaction is a critical factor in the design and fabrication of tissue engineering scaffolds. A particular peptide sequence, Arg-Gly-Asp (RGD peptide), is often used as an adhesion ligand in the engineering of different types of tissues. While in some cases this has been adequate, the use of multiple ligands may be required for the successful engineering of some tissue types. We hypothesized that hydrogels presenting both the RGD peptide and the YIGSR peptide (Tyr-Ile-Gly-Ser-Arg) could successfully regulate the phenotype of PC12 cells, thereby providing a new platform for effective tissue engineering applications...
January 3, 2017: Colloids and Surfaces. B, Biointerfaces
Jakub Grzesiak, Agnieszka Śmieszek, Krzysztof Marycz
BACKGROUND: Osteogenic differentiation of mesenchymal stem cells has been extensively investigated with regards to different aspects, including the analysis of cell intracellular and extracellular proteome, cell gene expression pattern, and morphology. During the osteogenic differentiation, osteoblasts produce and release specific proteins, like osteocalcin and osteopontin. Simultaneously, cells produce the extracellular matrix (ECM) that resembles the bone ECM, with high quantity of calcium and phosphorus...
2017: Cell & Bioscience
Sehrish Jabeen, Atif Islam, Abdul Ghaffar, Nafisa Gull, Ayesha Hameed, Anbreen Bashir, Tahir Jamil, Tousif Hussain
Silane crosslinked biopolymer based novel pH-responsive hydrogels were fabricated by blending the cationic (chitosan) and anionic (alginate) polymers with poly(vinyl alcohol). Tetraethoxysilane (TEOS) was used, as a crosslinker in different amounts due to its nonhazardous nature, to study its impact on physical and chemical properties of the prepared injectable hydrogels along with the controlled release of drug. The swelling response of the prepared hydrogels was examined in different solvent media which exhibited decreased swelling ratio with increase in the amount of TEOS...
January 4, 2017: International Journal of Biological Macromolecules
Masoud Rezvanain, Naveed Ahmad, Mohd Cairul Iqbal Mohd Amin, Shiow-Fern Ng
Natural polymer-based hydrogel films have great potential for biomedical applications and are good candidates for wound dressings. In this study, we aimed to develop simvastatin-loaded crosslinked alginate-pectin hydrogel films by ionic crosslinking to improve the mechanical characteristics, wound fluid uptake and drug release behavior. Alginate-pectin hydrocolloid films were chemically crosslinked by immersing in different concentrations of CaCl2 (0.5-3% w/v) for 2-20min. The degree of crosslinking was influenced by both contact time and CaCl2 concentration...
January 4, 2017: International Journal of Biological Macromolecules
Makoto Takenaka, Ki-Seok Yoon, Takahiro Matsumoto, Seiji Ogo
Pyruvate ferredoxin oxidoreductase from Citrobacter sp. S-77 (PFORS77) was purified in order to develop a method for acetyl-CoA production. Although the purified PFORS77 showed high O2-sensitivity, the activity could be remarkably stabilized in anaerobic conditions. PFORS77 was effectively immobilized on ceramic hydroxyapatite (PFORS77-HA) with an efficiency of more than 96%, however, after encapsulation of PFORS77-HA in alginate, the rate of catalytic acetyl-CoA production was highly reduced to 36% when compared to that of the free enzyme...
March 2017: Bioresource Technology
Zhongxue Tang, Yuanyuan Fu, Zhanfang Ma
In this work, multiple signal amplification strategies for ultrasensitive label-free electrochemical immunoassay for carbohydrate antigen 24-2 (CA242) were developed using redox sodium alginate-Pb(2+)-graphene oxide (SA-Pb(2+)-GO) hydrogel. The SA-Pb(2+)-GO hydrogel was synthesised by simply mixing SA, GO, and Pb(2+) and then implemented as a novel redox species with a strong current signal at -0.46V (vs. Ag/AgCl). After the three-dimensional and porous SA-Pb(2+)-GO hydrogel was in situ generated on a glassy carbon electrode (GCE), chitosan was adsorbed on the obtained electrode to further enrich Pb(2+)...
December 22, 2016: Biosensors & Bioelectronics
Khaow Tonsomboon, Annabel L Butcher, Michelle L Oyen
Mechanically robust hydrogels are required for many tissue engineering applications to serve as cell-supporting structures. Unlike natural tissues, the majority of existing tough hydrogels lack ordered microstructures organized to withstand specific loading conditions. In this work, electrospun gelatin nanofibres, mimicking the collagen network in native tissues, are used to strengthen and resist crack propagation in brittle alginate hydrogels. Aligned nanofibre reinforcement enhances the tensile strength of the hydrogels by up to two orders of magnitude...
March 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
Minsung Park, Sungchul Shin, Jie Cheng, Jinho Hyun
We describe the nanocomposite membrane for cell encapsulation using nanocelluose hydrogels. One of the surfaces of bacterial cellulose (BC) pellicles was coated with collagen to enhance cell adhesion and the opposite side of the BC pellicles was coated with alginate to protect transplanted cells from immune rejection by the reduced pore size of the composite membrane. The morphology of nanocomposite membrane was observed by scanning electron microscopy and the permeability of the membrane was estimated by the release test using different molecular weights of polymer solution...
February 20, 2017: Carbohydrate Polymers
Liu Yuan, Yu Wu, Qi-Sheng Gu, Hany El-Hamshary, Mohamed El-Newehy, Xiumei Mo
Recently, photocrosslinked hydrogels have attracted more and more attention in biomedical applications. In this study, a serials of injectable hydrogels were fabricated from aldehyde methacrylate sodium alginate and amino gelatin (AMSA/AG) using a two-step process. Here, sodium alginate, a kind of natural polysaccharide, was modified by oxidizer to form aldehyde sodium alginate (ASA), and methacrylate groups were further grafted on the main chain of ASA. Gelatin, the denatured form of collagen, was modified with ethylenediamine (ED) to graft more amino groups...
December 23, 2016: International Journal of Biological Macromolecules
Fu-Hsuan Tsai, Yutaka Kitamura, Mito Kokawa
Liquid-core hydrogel beads (LHB) were formulated through reverse spherification, by sodium alginate and using calcium lactate (CL) to replace the common calcium source, calcium chloride. The effect of four independent variables: first gelation time (X1), CL concentration in first gelation (X2), secondary gelation time (X3), and CL concentration in secondary gelation (X4), on seven physical properties of LHB: diameter, hardness (Y1), loading efficiency (LE, Y2), release amount of total phenolic compounds (TP) in simulated gastric (Y3) and small intestinal (Y4) fluid, swelling capacity (Y5), and sphericity (Y6), were evaluated...
December 23, 2016: International Journal of Biological Macromolecules
Max Darnell, Simon Young, Luo Gu, Nisarg Shah, Evi Lippens, James Weaver, Georg Duda, David Mooney
The rate of stress relaxation of adhesion substrates potently regulates cell fate and function in vitro, and in this study the authors test whether it can regulate bone formation in vivo by implanting alginate gels with differing rates of stress-relaxation carrying human mesenchymal stem cells into rat calvarial defects. After three months, the rats that received fast-relaxing hydrogels (t1/2 ≈ 50 s) show significantly more new bone growth than those that received slow-relaxing, stiffness-matched hydrogels...
December 20, 2016: Advanced Healthcare Materials
Julia Koehler, Leonie Wallmeyer, Sarah Hedtrich, Achim M Goepferich, Ferdinand P Brandl
The development of chronic wounds has been frequently associated with alkaline pH values. The application of pH-modulating wound dressings can, therefore, be a promising treatment option to promote normal wound healing. This study reports on the development and characterization of acidic hydrogel dressings based on interpenetrating poly(ethylene glycol) diacrylate/acrylic acid/alginate networks. The incorporation of ionizable carboxylic acid groups results in high liquid uptake up to 500%. The combination of two separate polymer networks significantly improves the tensile and compressive stability...
December 20, 2016: Macromolecular Bioscience
Qiushui Chen, Dong Chen, Jing Wu, Jin-Ming Lin
Designing cell-compatible, bio-degradable, and stimuli-responsive hydrogels is very important for biomedical applications in cellular delivery and micro-scale tissue engineering. Here, we report achieving flexible control of cellular microencapsulation, permeability, and release by rationally designing a diblock copolymer, alginate-conjugated poly(N-isopropylacrylamide) (Alg-co-PNiPAM). We use the microfluidic technique to fabricate the bifunctional copolymers into thousands of mono-disperse droplet-templated hydrogel microparticles for controlled encapsulation and triggered release of mammalian cells...
November 2016: Biomicrofluidics
Jenna Dumbleton, Pranay Agarwal, Haishui Huang, Nathaniel Hogrebe, Renzhi Han, Keith J Gooch, Xiaoming He
Advancements in tissue engineering require the development of new technologies to study cell behavior in vitro. This study focuses on stem cell behavior within various miniaturized three-dimensional (3D) culture conditions of alginate biomaterials modified with the Arg-Gly-Asp (RGD) peptide known for its role in cell adhesion/attachment. Human embryonic palatal mesenchyme (HEPM) cells, bone marrow derived mesenchymal stem cells (MSCs), and human adipose derived stem cells (ADSCs) were cultured on a flat hydrogel of different concentrations of alginate-RGD, and in the miniaturized 3D core of microcapsules with either a 2% alginate or 2% alginate-RGD shell...
June 2016: Cellular and Molecular Bioengineering
Joanna Lewandowska-Łańcucka, Katarzyna Mystek, Arn Mignon, Sandra Van Vlierberghe, Anna Łatkiewicz, Maria Nowakowska
The paper presents the synthesis, the physico-chemical and the biological properties of novel hybrid materials prepared from photo-crosslinked gelatin/alginate-based hydrogels and silica particles exhibiting potential for the regeneration of bone tissue. Both alginate and gelatin were functionalized with methacrylate and methacrylamide moieties, respectively to render them photo-crosslinkable. Submicron silica particles of two sizes were dispersed within three types of polymeric sols including alginate, gelatin, and gelatin/alginate blends, which were subsequently photo-crosslinked...
February 10, 2017: Carbohydrate Polymers
Huiyun Wen, Ting Gao, Zizhen Fu, Xing Liu, Jiatong Xu, Yishu He, Ningxia Xu, Ping Jiao, An Fan, Saipeng Huang, Weiming Xue
It is of high interest to obtain hydrogel membranes with optimum mechanical stability, which is a prerequisite to the successful fabrication of hydrogel microcapsules for cell separation. In this work, we developed magnetic responsive alginate/chitosan (MAC) hydrogel microcapsules by co-encapsulation of microbial cells and superparamagnetic iron oxide nanoparticles (SPIONs) reacting under a high voltage electrostatic field. We investigated the influence of the molecular weight of chitosan, microcapsules size, and membrane crosslinking time on the swelling behavior of microcapsules as an indicator of stability of the membranes...
February 10, 2017: Carbohydrate Polymers
Ji Hyun Kim, Saerom Park, Hyungsup Kim, Hyung Joo Kim, Yung-Hun Yang, Yong Hwan Kim, Sang-Kyu Jung, Eunsung Kan, Sang Hyun Lee
Alginate/bacterial cellulose nanocomposite beads, with well-controlled size and regular spherical shapes, were prepared in a simple manner by entrapping Gluconacetobacter xylinus in barium alginate hydrogel beads, followed by cultivation of the entrapped cells in culture media with a low sodium ion concentration. The entire surface of the alginate hydrogel beads containing the cells was covered with cellulose fibers (∼30nm) after 36h of cultivation. The cellulose crystallinity index of the alginate/bacterial cellulose beads was 0...
February 10, 2017: Carbohydrate Polymers
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