NanoBio Australia 2014 Biomaterials Science Poster Prize Winners

Biomaterials Science was delighted to award Poster Prizes at the NanoBio Australia 2014 conference held at  The University of Queensland, St. Lucia, Australia on 6th – 10th July 2014. The winner was Young-Seon Ko and the Runner-up was Ms Liyu Chen.
Young-Seon Ko and Liyu Chen receiving their poster prize.
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High throughput evaluation of surfaces for stem cell culture

Polymer microarrays for stem cell adhesion studies

This study identifies new surfaces optimized for human pluripotent stem cell expansion using a high-throughput polymer microarray chip.

The biomaterials community is moving toward using high-throughput tools to evaluate cell-material interactions at an unprecedented rate. For instance, polymer microarrays have become popular for identifying candidate surfaces that elicit a desired biological response. Using a single microarray chip, low volumes of polymer solution are deposited in a grid-like format using robotic ink-jet or contact printing. The chip is polymerized to manufacture a polymer microarray. After fabricating the microarray, cells are deposited directly onto the spots of the chip and cultured to determine materials that support a specific cell phenotype.

At the Laboratory of Biophysics and Surface Analysis at the University of Nottingham, Celiz et al. evaluated human pluripotent stem cell growth on a polymer microarray containing 141 varieties of (meth)acrylate and (meth)acrylamide photo-curable polymers. To maximize the diversity of the microarray, monomers containing a variety of nitrogen, fluorine, oxygen, aromatic, and aliphatic side chains were utilized.  Monomers were selected on their ability to be photo-polymerized by UV irradiation. The surface chemistry after polymerization was assessed using ToF-SIMS, and water contact angle measurements determined the surface wettability of each spot.

Partial least squares analysis (PLS) was utilized to correlate surface chemistry and wettability to identify surfaces that would yield high human pluripotent stem cell (hPSC) adhesion. Of the 141 surfaces screened in the array, 47 polymers supported hPSC attachment. Interestingly, no relationship was observed between surface wettability and cell adhesion, indicating wettability of a surface is not sufficient to predict hPSC adhesion. PLS analysis subsequently identified correlations between polymer surface chemistry and experimental hPSC adhesion. Additional experiments confirmed that increased protein adsorption on specific polymer spots was a contributor to cell adhesion to the polymer surface.

Collectively, the polymer array developed in this study was able to operate as a high-throughput tool to identify surfaces amenable to hPSC adhesion. Moving forward, polymer microarrays have the potential to identify a broad library of surfaces capable of supporting sustained hPSC growth and pluripotency.

Chemically diverse polymer microarrays and high throughput surface characterization: a method for discovery of materials for stem cell culture
A. D. Celiz, J. G. W. Smith, A. K. Patel, R. Langer, D. G. Anderson, D. A. Barrett, L. E. Young, M. C. Davies, C. Denning and M. R. Alexander
Biomater. Sci., 2014, Advance Article DOI: 10.1039/C4BM00054D

Brian Aguado is currently a Ph.D. Candidate and NSF Fellow in the Biomedical Engineering department at Northwestern University. He holds a B.S. degree in Biomechanical Engineering from Stanford University and a M.S. degree in Biomedical Engineering from Northwestern University. Read more about Brian’s research publications here.

Follow the latest journal news on Twitter @BioMaterSci or go to our Facebook page.

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2014 Biomaterials Science Lectureship Awarded to Suzie Pun

It is with great pleasure that we announce Professor Suzie Pun (University of Washington) as the recipient of the inaugural Biomaterials Science Lectureship.

This award, which will be an annual event for the journal,  honours a younger scientist who has made a significant contribution to the biomaterials field. The recipient is selected by the Biomaterials Science Editorial Board from a list of candidates nominated by the community.

More about Suzie…

Suzie H. Pun received her Chemical Engineering Ph.D. degree in 2000 from the California Institute of Technology.  She then worked as a senior scientist at Insert Therapeutics/Calando Pharmaceuticals for 3 years developing polymeric drug delivery systems before joining the Department of Bioengineering at University of Washington (UW).  She is currently the Robert J Rushmer Associate Professor of Bioengineering, an Adjunct Associate Professor of Chemical Engineering, and a member of the Molecular Engineering and Sciences Institute at UW.  Her research focus area is in drug and gene delivery systems and she has published over 70 research articles in this area.  Current application areas for her group include biologics delivery to the central nervous system and cancer.  For this work, she was recognized with a Presidential Early Career Award for Scientists and Engineers in 2006. 

Take a look at this paper for an example of Suzie’s recent research:

Comparative study of guanidine-based and lysine-based brush copolymers for plasmid delivery Peter M. Carlson, Joan G. Schellinger, Joshuel A. Pahang, Russell N. Johnson and Suzie H. Pun  
Biomater. Sci., 2013, 1, 736-744 DOI: 10.1039/C3BM60079C 

We would like to thank everybody who nominated a candidate for the Lectureship- we received many excellent nominations, and the Editorial Board had a difficult task in choosing between some outstanding candidates.

We invite you to join us in congratulating Suzie in the comments below.

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Top 10 Most-accessed Biomaterials Science articles – Q1 2014

This month sees the following articles in Biomaterials Science that are in the top ten most accessed from January – March:

Stimuli-responsive functionalized mesoporous silica nanoparticles for drug release in response to various biological stimuli 
Xin Chen, Xiaoyu Cheng, Alexander H. Soeriyadi, Sharon M. Sagnella, Xun Lu, Jason A. Scott, Stuart B. Lowe, Maria Kavallaris and J. Justin Gooding    
Biomater. Sci., 2014,2, 121-130
DOI: 10.1039/C3BM60148J  
  
Hyaluronic acid hydrogel stiffness and oxygen tension affect cancer cell fate and endothelial sprouting 
Yu-I Shen, Hasan E. Abaci, Yoni Krupski, Lien-Chun Weng, Jason A. Burdick and Sharon Gerecht    
Biomater. Sci., 2014,2, 655-665
DOI: 10.1039/C3BM60274E  
 
Hydrogel scaffolds as in vitro models to study fibroblast activation in wound healing and disease 
Megan E. Smithmyer, Lisa A. Sawicki and April M. Kloxin    
Biomater. Sci., 2014,2, 634-650
DOI: 10.1039/C3BM60319A  
  
Fabrication of zeolite–polymer composite nanofibers for removal of uremic toxins from kidney failure patients 
Koki Namekawa, Makoto Tokoro Schreiber, Takao Aoyagi and Mitsuhiro Ebara    
Biomater. Sci., 2014,2, 674-679
DOI: 10.1039/C3BM60263J  
 
Enzyme responsive materials: design strategies and future developments 
Mischa Zelzer, Simon J. Todd, Andrew R. Hirst, Tom O. McDonald and Rein V. Ulijn    
Biomater. Sci., 2013,1, 11-39
DOI: 10.1039/C2BM00041E  
 
Mesoporous silica nanoparticles for the design of smart delivery nanodevices 
Montserrat Colilla, Blanca González and María Vallet-Regí    
Biomater. Sci., 2013,1, 114-134
DOI: 10.1039/C2BM00085G  
  
Smart hydrogels as functional biomimetic systems 
Han L. Lim, Yongsung Hwang, Mrityunjoy Kar and Shyni Varghese    
Biomater. Sci., 2014,2, 603-618
DOI: 10.1039/C3BM60288E  
  
Non-eroding drug-releasing implants with ordered nanoporous and nanotubular structures: concepts for controlling drug release 
Moom Sinn Aw, Mima Kurian and Dusan Losic    
Biomater. Sci., 2014,2, 10-34
DOI: 10.1039/C3BM60196J  
 
Fracture-based micro- and nanofabrication for biological applications 
Byoung Choul Kim, Christopher Moraes, Jiexi Huang, M. D. Thouless and Shuichi Takayama    
Biomater. Sci., 2014,2, 288-296
DOI: 10.1039/C3BM60276A  
 
Nanoscale semiconductor devices as new biomaterials 
John Zimmerman, Ramya Parameswaran and Bozhi Tian    
Biomater. Sci., 2014,2, 619-626
DOI: 10.1039/C3BM60280J  

Why not take a look at the articles today and blog your thoughts and comments below.

Fancy submitting an article to Biomaterials Science? Then why not submit to us today!

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Cancer therapy with nanoparticles

Biomaterials Science web writer, Debanti Sengupta, highlights a HOT article from the journal

Researchers have demonstrated that controlling nanoparticle shape and packing can impact how cancer therapeutics interact with cells.

Photodynamic therapy is an innovative emerging therapy for cancer.  This therapeutic modality consists of introducing light-activated molecules known as ‘photosensitizers’ into cancer cells.  When activated with light, these photosensitizers are able to produce toxic molecules within the cells (also known as reactive oxygen species or ROS) that can eventually cause cancer cell death.  Photosensitizers are often introduced into the cells using nanoparticle carriers. In order for effective cell death to occur, ROS must be formed within the nanoparticles and then diffuse out of the nanoparticles into the cells.

In this article, Chu et al. have designed silica-based nanocarriers that can control how photosensitizers interact with cells. They previously found that when photosensitizer-loaded nanoparticles were packed more densely, the amount of ROS that was released decreased.  In contrast, more loosely packed nanoparticles allowed for greater release of ROS into cells. In this study, the researchers designed a third type of nanoparticle consisting of a gold nanorod coated with dense silica. They found that this third type of nanoparticle released photosensitizers much more efficiently than the either densely packed or loosely packed silica-only particles. They also discovered that the nanorod-based particles produced a different distribution of ROS as compared to the loose or dense silica-only particles. When cells were treated with these nanoparticles, loosely-packed silica particles and the nanorod-based particles demonstrated dramatic decreases in cell-viability due to the action of the photosensitizers. Further, while the silica-based loose and dense particles caused cells to die via a programmed cell death (apoptotic) route, the nanorod-based particles caused cell death via cell injury resulting in premature cell death (necrosis).

These experiments suggest that controlling the composition and shape of the nanoparticles that carry photosensitizers to cancer cells can alter both the number of cancer cells killed as well as the mechanism by which the cells die. This work has implications for future photodynamic therapeutic strategies.

Zhiqin Chu, Silu Zhang, Chun Yin, Ge Lin and Quan Li
Biomater. Sci., 2014, Advance Article DOI: 10.1039/C4BM00024B

Debanti Sengupta recently completed her PhD in Chemistry from Stanford University.  She is currently a Siebel postdoctoral scholar at the University of California, Berkeley.

Follow the latest journal news on Twitter @BioMaterSci or go to our Facebook page.

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Cerebellar neuron development on hybrid matrix constructs

The cerebellum is a region in the brain responsible for regulating motor control and cognitive functions such as attention and language. During development of the cerebellum (and of other tissues), cells interact with the surrounding microenvironment known as the extracellular matrix (ECM). These neuron-ECM interactions regulate neuronal differentiation, growth, formation of synapses, and neurite outgrowth. Specifically, ECM components including collagen and laminin-1 (lam-1) are known to regulate the alignment, migration, and neurite outgrowth of Purkinje cells (PCs). However, the dual signaling roles of collagen and laminin-1 during cerebellar tissue development have not been fully explored.

Dr. Shantanu Sur, a postdoctoral fellow in Prof. Samuel Stupp’s laboratory at Northwestern University, has collaborated with Dr. Thomas Launey at the RIKEN Brain Science Institute in Japan to explore cerebellar tissue development using biomaterial hydrogels. Sur has developed an artificial matrix consisting of collagen and synthetic peptide amphiphile (PA) molecules presenting IKVAV, the peptide on laminin-1 responsible for cell adhesion and neurite outgrowth. Sur et al. evaluated the spatiotemporal expression of lam-1 and collagen in rat cerebellums during PC development (embryonic to post-natal) using histology and immunostaining. Given the changes in the ratio of lam-1 to collagen during PC formation and growth, these results suggest the dynamic involvement of these ECM proteins in forming the neural architecture of the cerebellum.

Using a biomimetic approach to mimic the critical lam-1 to collagen ratio, Sur proceeded to model the dynamic nature of the ECM during PC development with a synthetic collagen-PA hydrogel. Collagen (types I-V) and IKVAV-PA molecules were mixed together in solution at varying concentrations and gelled using ammonia vapor. This simple method allowed Sur to evaluate the density of PC growth, axon guidance, and dendrite morphology in gels using a wide array of collagen and IKVAV-PA concentrations. Strikingly, effects on PC phenotype were observed as a function of the collagen:IKVAV-PA ratio and not the absolute concentrations of each ECM component within the matrix.

Sur comments that the hybrid matrix provides an easily tunable environment to enable the in vitro testing of the role of ECM signals on neuronal maturation. “Our study shows that the optimal ECM-derived cues for neurons change at specific stages of development,” Sur says. “This observation will drive us to work on the design of a dynamic matrix where the extracellular signals delivered to the neuron can be tuned spatiotemporally.” Additionally, the collagen/IKVAV-PA gels may be used to identify cell-ECM interactions during the development of other tissue types, given the simplicity of the technique.

Collectively, this study demonstrates the exciting use of engineered matrices to evaluate spatiotemporal cell-ECM interactions, with the hopes to further elucidate mechanisms of tissue development.

Synergistic regulation of cerebellar Purkinje neuron development by laminin epitopes and collagen on an artificial hybrid matrix construct
Shantanu Sur, Mustafa O. Guler, Matthew J. Webber, Eugene T. Pashuck, Masao Ito, Samuel I. Stupp, and Thomas Launey
Biomater. Sci., 2014, Advance Article, DOI: 10.1039/C3BM60228A

Brian Aguado is currently a Ph.D. Candidate and NSF Fellow in the Biomedical Engineering department at Northwestern University. He holds a B.S. degree in Biomechanical Engineering from Stanford University and a M.S. degree in Biomedical Engineering from Northwestern University. Read more about Brian’s research publications here.

To keep up-to-date with all the latest research, sign-up to our RSS feed or Table of contents

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Emerging Investigators themed issue now published

We are pleased to announce that the Biomaterials Science 2014 Emerging Investigators themed issue is now available to read online.

Edited by Phillip Messersmith and Norio Nakatsuji, co-Editors in Chief of Biomaterials Science, this issue highlights the exciting and important work being carried out by some of the most talented up-and-coming researchers in the field.  Read more about the issue in the Editorial.

Here is a sample of the reviews, communications and papers that feature in the Emerging Investigators themed issue:

On the cover

Fabrication of zeolite–polymer composite nanofibers for removal of uremic toxins from kidney failure patients Koki Namekawa, Makoto Tokoro Schreiber, Takao Aoyagi and Mitsuhiro Ebara 

 
Review
Smart hydrogels as functional biomimetic systems Han L. Lim, Yongsung Hwang, Mrityunjoy Kar and Shyni Varghese 
 
Minireviews
Peptoids for biomaterials science King Hang Aaron Lau 
 
Communications
 
Hyaluronic acid hydrogel stiffness and oxygen tension affect cancer cell fate and endothelial sprouting Yu-I Shen, Hasan E. Abaci, Yoni Krupski, Lien-Chun Weng, Jason A. Burdick and Sharon Gerecht
 
Papers
Translocation of flexible polymersomes across pores at the nanoscale Carla Pegoraro, Denis Cecchin, Jeppe Madsen, Nicholas Warren, Steven P. Armes, Sheila MacNeil, Andrew Lewis and Giuseppe Battaglia
 
Structural reinforcement of cell-laden hydrogels with microfabricated three dimensional scaffolds Chaenyung Cha, Pranav Soman, Wei Zhu, Mehdi Nikkhah, Gulden Camci-Unal, Shaochen Chen and Ali Khademhosseini
 
Integrative and comparative analysis of coiled-coil based marine snail egg cases – a model for biomimetic elastomers Paul A. Guerette, Gavin Z. Tay, Shawn Hoon, Jun Jie Loke, Arif F. Hermawan, Clemens N. Z. Schmitt, Matthew J. Harrington, Admir Masic, Angelo Karunaratne, Himadri S. Gupta, Koh Siang Tan, Andreas Schwaighofer, Christoph Nowak and Ali Miserez
 
 
Molecular farming of fluorescent virus-based nanoparticles for optical imaging in plants, human cells and mouse models S. Shukla, C. Dickmeis, A. S. Nagarajan, R. Fischer, U. Commandeur and N. F. Steinmetz 
 
More papers from the themed issue can be downloaded here.
 
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Cells as Legos: Using cells for gelation of hydrophobically-modified polymers

Engineering tissue mimics in vitro using cells and materials is one of the core goals of biomaterials science. To develop a tailored cell culture environment, natural and/or synthetic hydrogels are used to mimic the extracellular matrix. Cells are embedded in a hydrogel matrix in a process known as “encapsulation.” During encapsulation, polymers in solution are chemically or physically cross-linked to immobilize cells in a mesh-like structure. The cell-loaded hydrogels are subsequently used for various regenerative medicine applications.

Researchers at the University of Maryland have developed a novel encapsulation technique for embedding cells in hydrogel materials. Instead of passively encapsulating cells in the polymer mesh, cells serve as “active structural elements” and are connected to the polymer chains. Using hydrophobically-modified (hm) alginate and chitosan, hydrophobic regions along the polymer chains are physically embedded in the hydrophobic cell membrane. The cells serve as struts to link together the polymer mesh. Rheological studies were performed to confirm the sol-gel transition when hm-polymers were combined to form gels (unmodified polymer controls did not form gels). To show the versatility of the system, various cell types were used to form gels with hm-alginate and hm-chitosan, including human umbilical vein endothelial cells (HUVECs), MCF7 breast cancer cells, and blood cells.

Analogous to building block toys such as Legos, the non-covalent hm-polymer and cell interactions are reversible with the addition of excess hydrophobic binding “pockets.” Using α-cyclodextrin, the gels are immediately transformed into free-flowing solutions (confirmed using rheology). The α-cyclodextrin serves to sequester the hydrophobic tails of the hm-polymer and gently release the cells from the mesh. Interestingly, α-cyclodextrin does not affect cell viability because the molecule is not large enough to bind two-tailed lipids of the cell membrane. Viability of the cells was confirmed before and after the gentle release from the gel, indicating that cell membranes remained unharmed during the gel reversal process.

Taken together, hm-polymers could serve as a unique technique to embed and release cells from a hydrogel matrix. Using cells as building blocks is highly desirable for several applications including 3D cell culture models and injectable cell therapies.

Reversible gelation of cells using self-assembling hydrophobically-modified biopolymers: toward self-assembly of tissue
Vishal Javvaji, Matthew B. Dowling, Hyuntaek Oh, Ian M. White and Srinivasa R. Raghavan
Biomater. Sci., 2014, Advance Article, DOI: 10.1039/C4BM00017J

Brian Aguado is currently a Ph.D. Candidate and NSF Fellow in the Biomedical Engineering department at Northwestern University. He holds a B.S. degree in Biomechanical Engineering from Stanford University and a M.S. degree in Biomedical Engineering from Northwestern University. Read more about Brian’s research publications here.

To keep up-to-date with all the latest research, sign-up to our RSS feed or Table of contents

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Third Symposium on Innovative Polymers for Controlled Delivery Sponsorship

We are pleased to announce that The 3rd Symposium on Innovative Polymers for Controlled Delivery (SIPCD 2014)

In Honor of Prof. Dr. Jan Feijen’s 70th Birthday

will be held on September 16-19, 2014 in the Garden Hotel, Suzhou, China

The symposium is co-organized by Soochow University and Changchun Institute of Applied Chemistry, Chinese Academy of Sciences. SIPCD 2014 will welcome approximately 450 delegates, with 31 invited lectures and 220 poster presentations. The whole symposium is organized in one single session. It will also include a stimulating Debate on Drug Delivery.

Invited speakers include Biomaterials Science board members Jianjun Cheng and Jun Wang. A full list of International Plenary Speakers can be found here.

Please see the conference website to register your attendance or submit an abstract.

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Controlling neuronal behavior with nano-topography

Morphological and cellular changes in neurons in response to different nanotopographies

The ability to control neuronal behavior and growth is highly sought among researchers interested in neuro-regenerative medicine.  Over the past two decades, it has become widely accepted that modifications in a substrate’s physical surface topography can influence the growth patterns of seeded neurites.  However, the advent of techniques that are capable of fabricating nano-textured surfaces has revealed that the magnitude of this influence may be much greater than originally thought.  In this paper, a group of scientists from KAIST review a number of recent advances in the development of nano-topographies which can influence neuronal behavior.

Many of these advances revolve around improving neural adhesion, providing directional guidance for axonal growth, and accelerating the speed of neurite outgrowth.  Numerous groups have become interested in using nanowire arrays to improve neuron adhesion, eliminating the need for any additional surface coating.  In a 2010 Nano Letters publication, Xie et al. were able to demonstrate the creation of a silicon nanopillar array that could selectively pin cortical neurons to desired locations.  Any cells that were seeded onto, or later came into contact with the nanopillars became immobilized, enabling a long-term observational study of their electrical activity.  Other groups have found that nanofiber bundles make excellent scaffolding materials for neurons and can be used to direct and align neurite growth.  In addition, when compared to planar surfaces, nanofiber-based substrates were shown to increase the speed at which initial neurite formation occurred.

Although the benefits of nano-textured substrates are clear, the mechanism by which neurons translate these physical cues into biological signals is still something of a mystery.  However, many of the reviewed papers suggest that actin filaments and focal adhesions (FA) play a major role.  One group found that f-actin often forms networks which resemble the shape of the underlying surface topography and that the impairment of f-actin polymerization completely erases any ability neurons have to respond to nanotopographical cues.  Other groups have demonstrated that the size of FA is proportional to the degree of neuronal alignment with underlying surface structures.  An increase in alignment leads to a larger FA which ultimately results in a more stable neurite attachment.

Regardless of the mechanism, it has become clear in recent years that nanotopography is an important parameter for the controlled manipulation of neuronal behavior.  In this mini-review, Kim et al. are able to provide an interesting overview on the progress that has already been made within this area.

Neurons on nanometric topographies: insights into neuronal behaviors in vitro
M. Kim, M. Park, K. Kang, and I.S. Choi.
Biomater. Sci., 2014, 2, 148-155 DOI: 10.1039/C3BM60255A

Ellen Tworkoski is a guest web-writer for Biomaterials Science.  She is currently a graduate student in the biomedical engineering department at Northwestern University (Evanston, IL, USA).

Follow the latest journal news on Twitter @BioMaterSci or go to our Facebook page.

To keep up-to-date with all the latest research, sign-up to our RSS feed or Table of contents alert.

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